U.S. patent application number 15/538402 was filed with the patent office on 2017-12-07 for plant cultivation device.
This patent application is currently assigned to NATUREDYNE INC.. The applicant listed for this patent is NATUREDYNE INC.. Invention is credited to Keiichi NAKAJIMA.
Application Number | 20170347538 15/538402 |
Document ID | / |
Family ID | 56244712 |
Filed Date | 2017-12-07 |
United States Patent
Application |
20170347538 |
Kind Code |
A1 |
NAKAJIMA; Keiichi |
December 7, 2017 |
PLANT CULTIVATION DEVICE
Abstract
The present invention is a plant cultivation device. The water
tank supplies cultivation water to the cultivation tank via an
irrigation conduit. The water tank also suctions cultivation water
from the cultivation tank via a water-sucking pipe. The
heat-collecting part receives sunlight, and the pressure of air
that is heated inside the air-storage part presses the surface of
the water inside the water tank. The water tank supplies
cultivation water that has been pressed by said air to a culture
medium material. The heat-collecting part raises the surface of the
water inside the water tank as a result of the heated air being
cooled by a decrease in the sunlight. The water tank suctions
cultivation water from a bottom section of the cultivation
tank.
Inventors: |
NAKAJIMA; Keiichi; (Tokyo,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NATUREDYNE INC. |
Tokyo |
|
JP |
|
|
Assignee: |
NATUREDYNE INC.
Tokyo
JP
|
Family ID: |
56244712 |
Appl. No.: |
15/538402 |
Filed: |
March 10, 2016 |
PCT Filed: |
March 10, 2016 |
PCT NO: |
PCT/JP2016/001344 |
371 Date: |
June 21, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
Y02P 60/12 20151101;
A01G 27/00 20130101; A01G 31/02 20130101; A01G 24/35 20180201; Y02P
60/21 20151101; A01G 27/005 20130101; A01G 2031/006 20130101; Y02A
40/266 20180101; A01G 27/003 20130101; Y02P 60/124 20151101; A01G
9/243 20130101; Y02A 40/27 20180101; Y02P 60/216 20151101; Y02A
40/25 20180101; A01G 9/247 20130101 |
International
Class: |
A01G 9/24 20060101
A01G009/24; A01G 27/00 20060101 A01G027/00; A01G 31/02 20060101
A01G031/02 |
Foreign Application Data
Date |
Code |
Application Number |
May 15, 2015 |
JP |
PCT/JP2015/002466 |
Claims
1. A plant cultivation device, comprising: a cultivation tank for
growing a plant; a water tank for supplying cultivation water to
the cultivation tank via a watering channel and for suctioning the
cultivation water from the cultivation tank via a water-sucking
pipe; and a heat-collecting part having an air-storage part that
communicates with an upper section of the water tank, wherein the
heat-collecting part receives sunlight and causes pressure of air
heated inside the air-storage part to press a surface of water
inside the water tank, the water tank supplies the cultivation
water that has been pressed by air to a culture medium material
arranged inside the cultivation tank from above through the
watering channel, the heat-collecting part causes the surface of
water inside the water tank to be raised as a result of cooling the
heated air caused by a decrease of the sunlight, and the water tank
suctions the cultivation water from a bottom section of the
cultivation tank via the water-sucking pipe in accordance with
rising of the cultivation water.
2. The plant cultivation device according to claim 1, further
comprising: a discharge check valve that prevents backflow of the
cultivation water supplied from the water tank to the cultivation
tank; and a suction check valve that prevents backflow of the
cultivation water suctioned from the cultivation tank to the water
tank, wherein the discharge check valve and the suction check valve
each include a valve member having a downwardly tapered conical
shape and a specific gravity larger than the cultivation water, and
a valve seat having a downwardly tapered funnel-like shape
conforming to a shape of the valve member, the water-sucking pipe
is shut by the valve member and the valve seat of the suction check
valve making surface contact with each other due to gravity, as
well as by a pressure of the cultivation water whose surface has
been pressed by the heat-collecting part inside the water tank
exceeding a pressure of the cultivation water inside the
water-sucking pipe, the watering channel is opened by the valve
member and the valve seat of the discharge check valve separating
from each other by a pressure of the cultivation water whose
surface has been pressed by the heat-collecting part inside the
water tank exceeding a pressure of the cultivation water inside the
watering channel, and consequently, the cultivation water in the
water tank is fed to the cultivation tank through the watering
channel, the watering channel is shut by the valve member and the
valve seat of the discharge check valve making surface contact with
each other due to gravity, as well as by a pressure of the
cultivation water whose surface has been raised by the
heat-collecting part inside the water tank falling below a pressure
of the cultivation water inside the watering channel, and the
water-sucking pipe is opened by the valve member and the valve seat
of the suction check valve separating from each other by a pressure
of the cultivation water whose surface has been raised by the
heat-collecting part inside the water tank falling below a pressure
of the cultivation water inside the water-sucking pipe, and
consequently, the cultivation water is fed from the cultivation
tank through the water-sucking pipe in accordance with rising of
the cultivation water in the water tank.
3. The plant cultivation device according to claim 2, wherein the
discharge check valve and the suction check valve are positioned
outside the water tank and detachable for the watering channel and
the water-sucking pipe.
4. The plant cultivation device according to claim 2, wherein the
discharge check valve and the suction check valve each further
include a cover and a base, the base having the valve seat, the
valve member being disposed between the cover and the valve seat,
the cover and the base having threads, and threads of the cover
capable of being removed and mated with threads of the base.
5. The plant cultivation device according to claim 1, further
comprising a water replenishing device that replenishes the
cultivation water to the cultivation tank via a filter material
arranged in the bottom section of the cultivation tank, wherein the
water replenishing device includes a water refill tank that stores
the cultivation water, a suction pressure part that replenishes the
cultivation water to the cultivation tank via the filter material,
and a water refill tube that feeds the cultivation water stored in
the water refill tank into an upper space of the suction pressure
part, the cultivation water in the water refill tank being fed into
the upper space of the suction pressure part by a drop of water
level in the suction pressure part caused by replenishment of the
cultivation water by the suction pressure part.
6. The plant cultivation device according to claim 5, wherein the
suction pressure part is a separate body from the cultivation
tank.
7. The plant cultivation device according to claim 5, wherein the
suction pressure part and the cultivation tank are integrated,
sharing walls, and the filter material extends to a bottom section
of the suction pressure part.
8. The plant cultivation device according to claim 5, wherein a
plurality of the water refill tanks are arranged stepwise so that a
water level difference occurs between one of the water refill tanks
and another of the water refill tanks, and an upper-side water
refill tank is provided with a water supply means for supplying the
cultivation water in the upper-side water refill tank to a
lower-side water refill tank.
9. The plant cultivation device according to claim 5, wherein the
water replenishing device further includes an adjuster provided to
the water refill tube, and the adjuster adjusts flow rate of the
cultivation water inside the water refill tube.
10. The plant cultivation device according to claim 5, wherein the
cultivation tank further includes a supporter that is arranged
inside the cultivation tank and supports the culture medium
material, and the supporter has an upwardly or downwardly tapered
funnel-like shape to form a space between the filter material and a
bottom part of the culture medium material.
11. The plant cultivation device according to claim 1, further
comprising: two or more cultivation tanks for growing the plant;
one heat-collecting part communicating with the two or more
cultivation tanks; and an air feed pipe through which the
heat-collecting part communicates with the water tank, through
which pressure of air that has been heated by the heat-collecting
part transmits, and through which pressure of the air that has been
cooled by the heat-collecting part transmits, wherein the
heat-collecting part conveys a change of the pressure of the heated
air to the water tank through the air feed pipe to cause the
surface of water in the water tank to be pressed by pressure of the
heated air, and the heat-collecting part conveys a change of the
pressure of the cooled air to the water tank through the air feed
pipe to cause the surface of water in the water tank to be raised
by pressure of the cooled air.
12. The plant cultivation device according to claim 1, wherein the
heat-collecting part includes a heat-collecting body positioned
inside the air-storage part.
13. The plant cultivation device according to claim 1, wherein the
culture medium material has an upwardly tapered conical shape, the
culture medium material has restorability in a direction in which a
distal end of the conical shape appears above the water surface
when the culture medium material is floating on the cultivation
water, the distal end has a seed receiving part where a seed of the
plant is embedded, and the culture medium material expands when
immersed in the cultivation water.
14. The plant cultivation device according to claim 1, further
comprising a water replenishing device that replenishes the
cultivation water to the cultivation tank via a filter material
arranged in the bottom section of the cultivation tank, wherein the
water replenishing device includes a water refill tank that stores
the cultivation water, a water storage part that replenishes the
cultivation water to the cultivation tank via the filter material,
a suction pressure part that communicates with the water storage
part and is positioned higher than the water storage part so as to
feed the cultivation water to the water storage part by gravity,
and a water refill tube that feeds the cultivation water stored in
the water refill tank into an upper space of the suction pressure
part, the cultivation water in the water refill tank being fed into
the upper space of the suction pressure part by a drop of water
level in the suction pressure part caused by replenishment of the
cultivation water by the suction pressure part.
15. The plant cultivation device according to claim 1, further
comprising: a discharge check valve that prevents backflow of the
cultivation water supplied from the water tank to the cultivation
tank; a suction check valve that prevents backflow of the
cultivation water suctioned from the cultivation tank to the water
tank; a connection pipe that connects the discharge check valve and
the suction check valve; and a water inlet pipe that connects a
middle portion of the connection pipe with the water tank, wherein
the water-sucking pipe is shut by the suction check valve being
closed by a pressure of the cultivation water whose surface has
been pressed by the heat-collecting part inside the water tank
exceeding a pressure of the cultivation water inside the
water-sucking pipe, the watering channel is opened by the discharge
check valve being opened by a pressure of the cultivation water
whose surface has been pressed by the heat-collecting part inside
the water tank exceeding a pressure of the cultivation water inside
the watering channel, and consequently, the cultivation water in
the water tank is fed to the cultivation tank through the watering
channel, the watering channel is shut by the discharge check valve
being closed by a pressure of the cultivation water whose surface
has been raised by the heat-collecting part inside the water tank
falling below a pressure of the cultivation water inside the
watering channel, and the water-sucking pipe is opened by the
suction check valve being opened by a pressure of the cultivation
water whose surface has been raised by the heat-collecting part
inside the water tank falling below a pressure of the cultivation
water inside the water-sucking pipe, and consequently, the
cultivation water is fed from the cultivation tank through the
water-sucking pipe in accordance with rising of the cultivation
water in the water tank.
16. The plant cultivation device according to claim 1, further
comprising: a discharge check valve that prevents backflow of the
cultivation water supplied from the water tank to the cultivation
tank; and a suction check valve that prevents backflow of the
cultivation water suctioned from the cultivation tank to the water
tank, wherein the discharge check valve and the suction check valve
are each formed of a valve member having a flexible bill part, the
flexible bill part has a slit and a notch on an upper side at a
distal end of the flexible bill part, the slit is provided only in
the notch positioned at a center of the upper side, the
water-sucking pipe is shut by the slit of the suction check valve
being closed by a pressure of the cultivation water whose surface
has been pressed by the heat-collecting part inside the water tank
exceeding a pressure of the cultivation water inside the
water-sucking pipe, the watering channel is opened by the slit of
the discharge check valve being opened by a pressure of the
cultivation water whose surface has been pressed by the
heat-collecting part inside the water tank exceeding a pressure of
the cultivation water inside the watering channel, and
consequently, the cultivation water in the water tank is fed to the
cultivation tank through the watering channel, the watering channel
is shut by the slit of the discharge check valve being closed by a
pressure of the cultivation water whose surface has been raised by
the heat-collecting part inside the water tank falling below a
pressure of the cultivation water inside the watering channel, and
the water-sucking pipe is opened by the slit of the suction check
valve being opened by a pressure of the cultivation water whose
surface has been raised by the heat-collecting part inside the
water tank falling below a pressure of the cultivation water inside
the water-sucking pipe, and consequently, the cultivation water is
fed from the cultivation tank through the water-sucking pipe in
accordance with rising of the cultivation water in the water
tank.
17. The plant cultivation device according to claim 1, comprising
two or more cultivation tanks for growing the plant, wherein the
watering channel is a duct that has branches and distributes water
to each of the two or more cultivation tanks by branching, and a
sponge is mounted at a discharge port of the watering channel that
leads to the cultivation tank.
18. The plant cultivation device according to claim 1, further
comprising a water replenishing device that replenishes the
cultivation water to the cultivation tank via a filter material
arranged in the bottom section of the cultivation tank, wherein the
water replenishing device includes a water refill tank that stores
the cultivation water, a suction pressure part that feeds the
cultivation water to the cultivation tank via the filter material,
and a water refill tube that feeds the cultivation water stored in
the water refill tank into an upper space of the suction pressure
part, the cultivation water in the water refill tank being fed into
the upper space of the suction pressure part by a drop of water
level in the suction pressure part caused by replenishment of the
cultivation water by the suction pressure part, the plant
cultivation device further comprising a water feeder that
communicates with the water refill tank and supplies the
cultivation water to the water replenishing device, the water
feeder having a ballcock.
19. The plant cultivation device according to claim 18, further
comprising an other water replenishing device, wherein the water
refill tank of the other water replenishing device communicates
indirectly with the water feeder via the water refill tank that
communicates with the water feeder.
20. The plant cultivation device according to claim 1, wherein the
culture medium material includes gel particles containing a
fertilizer component.
Description
TECHNICAL FIELD
[0001] The present invention relates to a plant cultivation
device.
BACKGROUND ART
[0002] PTL 1 discloses a plant cultivation device that irrigates
plants with water by a watering pump. This plant cultivation device
further includes a power supply device. The power supply device
converts wind or sunlight to electric power and supplies this
electric power to the watering pump.
CITATION LIST
Patent Literature
[0003] [PTL 1] Japanese Patent Application Laid-open No.
2003-210040
SUMMARY OF INVENTION
Technical Problem
[0004] The invention described in PTL 1 enables a reduction in
electric power required for maintenance of the plant cultivation
device. However, this plant cultivation device additionally
requires electric power for controlling the power supply device. In
cultivating plants with such a plant cultivation device, it is
necessary not only to take care of the plants but also to manage
the power supply device. This imposes a large burden on users.
[0005] An object of the present invention is to reduce the
dependency on external power supply and electric control of plant
cultivation devices.
Solution to Problem
[0006] [1] The plant cultivation device according to one aspect of
the present invention includes a cultivation tank for growing
plants, and a solar heat pump system. The solar heat pump system
includes a water tank that supplies cultivation water to the
cultivation tank via a watering channel. The water tank is also a
water tank for suctioning cultivation water from the cultivation
tank via a water-sucking pipe. The solar heat pump system further
includes a heat-collecting part that has an air-storage part that
communicates with an upper section of the water tank. The
heat-collecting part receives sunlight and causes the pressure of
air heated inside the air-storage part to press the surface of the
water inside the water tank. The water tank supplies the
cultivation water that has been pressed by the air to a culture
medium material. The water tank thus supplies water via the
watering channel. The water tank supplies water from above the
culture medium material that is arranged inside the cultivation
tank. The heat-collecting part raises the surface of the water
inside the water tank. This rising of the water level occurs as a
result of the heated air being cooled by a decrease of the
sunlight. The water tank suctions the cultivation water from a
bottom section of the cultivation tank via the water-sucking pipe.
This suctioning occurs in accordance with the rising of the
cultivation water.
[0007] [2] Preferably, the solar heat pump system further includes
a discharge check valve that prevents backflow of the cultivation
water supplied from the water tank to the cultivation tank.
Preferably, the solar heat pump system further includes a suction
check valve that prevents backflow of the cultivation water
suctioned from the cultivation tank to the water tank. The
discharge check valve and the suction check valve preferably have a
valve member with a specific gravity larger than the cultivation
water. This valve member preferably has a downwardly tapered
conical shape. These check valves preferably further have a valve
seat with a funnel-like shape. This funnel-like shape preferably
has a downwardly tapered shape conforming to the shape of the valve
member.
[0008] Preferably, the pressure of the cultivation water whose
surface has been pressed by the heat-collecting part inside the
water tank exceeds the pressure of the cultivation water inside the
watering channel. This preferably causes the valve member and the
valve seat of the discharge check valve to separate from each
other. Preferably, this opens the watering channel. Meanwhile,
preferably, the water-sucking pipe is shut by the valve member and
the valve seat of the suction check valve making surface contact
with each other due to gravity, as well as by the pressure of the
cultivation water whose surface has been pressed by the
heat-collecting part inside the water tank exceeding the pressure
of the cultivation water inside the water-sucking pipe. Preferably,
as a result of this, the cultivation water inside the water tank is
fed to the cultivation tank through the watering channel.
Preferably, the pressure of the cultivation water whose surface has
been raised by the heat-collecting part inside the water tank falls
below the pressure of the cultivation water inside the
water-sucking pipe. This preferably causes the valve member and the
valve seat of the suction check valve to separate from each other.
Preferably, this opens the water-sucking pipe. Meanwhile,
preferably, the watering channel is shut by the valve member and
the valve seat of the discharge check valve making surface contact
with each other due to gravity, as well as by the pressure of the
cultivation water whose surface has been raised by the
heat-collecting part inside the water tank falling below the
pressure of the cultivation water inside the watering channel.
Preferably, as a result of this, the cultivation water is fed from
the cultivation tank through the water-sucking pipe in accordance
with the rising of the cultivation water inside the water tank.
[0009] [3] The discharge check valve and the suction check valve
are preferably located outside the water tank. Preferably, these
check valves are detachable for the watering channel and the
water-sucking pipe.
[0010] [4] The discharge check valve and the suction check valve
each preferably further include a cover and a base. The base
preferably has the valve seat. The valve member is preferably
disposed between the cover and the valve seat. The cover and the
base preferably have threads. Preferably, threads of the cover are
removably mated with threads of the base.
[0011] [5] The plant cultivation device preferably further includes
a water replenishing device that replenishes the cultivation water
to the cultivation tank. This replenishment preferably takes place
via a filter material disposed in the bottom section of the
cultivation tank. The water replenishing device preferably has a
water refill tank that stores the cultivation water. The water
replenishing device preferably further includes a suction pressure
part that replenishes the cultivation water to the cultivation tank
via the filter material. The water replenishing device preferably
further includes a water refill tube that feeds the cultivation
water stored in the water refill tank into an upper space of the
suction pressure part. Replenishment of the cultivation water by
the suction pressure part preferably causes a drop of the water
level inside the suction pressure part. This preferably causes the
cultivation water inside the water refill tank to be fed into the
upper space of the suction pressure part.
[0012] [6] The suction pressure part is preferably a separate body
from the cultivation tank.
[0013] [7] Alternatively, the suction pressure part and the
cultivation tank are preferably integrated, sharing the walls. In
this case, the filter material preferably extends to a bottom
section of the suction pressure part.
[0014] [8] Preferably, a plurality of the water refill tanks are
disposed stepwise. The water refill tanks are preferably arranged
such that there is a water level difference between one of the
water refill tanks and another of the water refill tanks. An
upper-side water refill tank is preferably provided with a water
supply means. This water supply means preferably supplies the
cultivation water in the upper-side water refill tank to a
lower-side water refill tank.
[0015] [9] The water replenishing device preferably further
includes an adjuster provided to the water refill tube. The
adjuster preferably adjusts the flow rate of the cultivation water
inside the water refill tube.
[0016] [10] The cultivation tank preferably further includes a
supporter that supports a culture medium material. The supporter is
preferably disposed inside the cultivation tank. The supporter
preferably has an upwardly or downwardly tapered funnel-like shape.
The supporter, by having this funnel-like shape, preferably forms a
space between the filter material and a bottom part of the culture
medium material.
[0017] [11] The plant cultivation device preferably includes two or
more cultivation tanks. The plant cultivation device preferably
includes one heat-collecting part that communicates with the two or
more cultivation tanks. The plant cultivation device preferably
further includes an air feed pipe that communicates the
heat-collecting part with the water tank. The air feed pipe
preferably allows the pressure of the air heated by the
heat-collecting part to travel to the water tank. The air feed pipe
preferably allows the pressure of the air cooled by the
heat-collecting part to travel to the water tank. The
heat-collecting part preferably conveys changes of the pressure of
the heated air to the water tank through the air feed pipe. This
preferably causes the heat-collecting part to press the surface of
the water inside the water tank with the pressure of the heated
air. The heat-collecting part preferably conveys changes of the
pressure of the cooled air to the water tank through the air feed
pipe. This preferably causes the heat-collecting part to raise the
surface of the water inside the water tank with the pressure of the
cooled air.
[0018] [12] The heat-collecting part preferably includes a
heat-collecting body positioned inside the air-storage part.
[0019] [13] The culture medium material preferably has an upwardly
tapered conical shape. The culture medium material preferably has
restorability in a direction in which a distal end of the conical
shape appears above the water surface when the culture medium
material is floating on the cultivation water. The culture medium
material preferably has a seed receiving part at the distal end
where a seed of the plant is embedded. The culture medium material
preferably expands when immersed in the cultivation water.
[0020] [14] The plant cultivation device preferably further
includes a water replenishing device that replenishes the
cultivation water to the cultivation tank via a filter material
arranged in the bottom section of the cultivation tank. The water
replenishing device preferably includes a water refill tank that
stores the cultivation water, a water storage part that replenishes
the cultivation water to the cultivation tank via the filter
material, a suction pressure part that communicates with the water
storage part and is positioned higher than the water storage part
so as to feed the cultivation water to the water storage part by
gravity, and a water refill tube that feeds the cultivation water
stored in the water refill tank into an upper space of the suction
pressure part. Preferably, the cultivation water in the water
refill tank is fed into the upper space of the suction pressure
part by a drop of the water level inside the suction pressure part
caused by replenishment of the cultivation water by the suction
pressure part.
[0021] [15] The plant cultivation device preferably further
includes a discharge check valve that prevents backflow of the
cultivation water supplied from the water tank to the cultivation
tank, a suction check valve that prevents backflow of the
cultivation water suctioned from the cultivation tank to the water
tank, a connection pipe that connects the discharge check valve and
the suction check valve, and a water inlet pipe that connects a
middle portion of the connection pipe with the water tank.
[0022] Preferably, the water-sucking pipe is shut by the suction
check valve being closed by the pressure of the cultivation water
whose surface has been pressed by the heat-collecting part inside
the water tank exceeding the pressure of the cultivation water
inside the water-sucking pipe. Preferably, the watering channel is
opened by the discharge check valve being opened by the pressure of
the cultivation water whose surface has been pressed by the
heat-collecting part inside the water tank exceeding the pressure
of the cultivation water inside the watering channel, as a result
of which the cultivation water in the water tank is fed to the
cultivation tank through the watering channel. Preferably, the
watering channel is shut by the discharge check valve being closed
by the pressure of the cultivation water whose surface has been
raised by the heat-collecting part inside the water tank falling
below the pressure of the cultivation water inside the watering
channel. Preferably, the water-sucking pipe is opened by the
suction check valve being opened by the pressure of the cultivation
water whose surface has been raised by the heat-collecting part
inside the water tank falling below the pressure of the cultivation
water inside the water-sucking pipe, as a result of which the
cultivation water is fed from the cultivation tank through the
water-sucking pipe in accordance with the rising of the cultivation
water in the water tank.
[0023] [16] The plant cultivation device preferably further
includes a discharge check valve that prevents backflow of the
cultivation water supplied from the water tank to the cultivation
tank, and a suction check valve that prevents backflow of the
cultivation water suctioned from the cultivation tank to the water
tank. The discharge check valve and the suction check valve each
preferably be formed of a valve member having a flexible bill part.
The bill part preferably has a slit and a notch on an upper side at
a distal end of the bill part. The slit is preferably provided only
in the notch positioned at the center of the upper side.
[0024] Preferably, the water-sucking pipe is shut by the slit of
the suction check valve being closed by the pressure of the
cultivation water whose surface has been pressed by the
heat-collecting part inside the water tank exceeding the pressure
of the cultivation water inside the water-sucking pipe. Preferably,
the watering channel is opened by the slit of the discharge check
valve being opened by the pressure of the cultivation water whose
surface has been pressed by the heat-collecting part inside the
water tank exceeding the pressure of the cultivation water inside
the watering channel, as a result of which the cultivation water in
the water tank is fed to the cultivation tank through the watering
channel. Preferably, the watering channel is shut by the slit of
the discharge check valve being closed by the pressure of the
cultivation water whose surface has been raised by the
heat-collecting part inside the water tank falling below the
pressure of the cultivation water inside the watering channel.
Preferably, the water-sucking pipe is opened by the slit of the
suction check valve being opened by the pressure of the cultivation
water whose surface has been raised by the heat-collecting part
inside the water tank falling below the pressure of the cultivation
water inside the water-sucking pipe, as a result of which the
cultivation water is fed from the cultivation tank through the
water-sucking pipe in accordance with the rising of the cultivation
water in the water tank.
[0025] [17] The plant cultivation device preferably includes two or
more cultivation tanks. The watering channel is preferably a duct
that has branches and distributes water to each of the two or more
cultivation tanks by branching. A sponge is preferably mounted at a
discharge port of the watering channel that leads to the
cultivation tank.
[0026] [18] The plant cultivation device preferably includes a
water replenishing device that replenishes the cultivation water to
the cultivation tank via a filter material arranged in the bottom
section of the cultivation tank. The water replenishing device
preferably includes a water refill tank that stores the cultivation
water, a suction pressure part that feeds the cultivation water to
the cultivation tank via the filter material, and a water refill
tube that feeds the cultivation water stored in the water refill
tank into an upper space of the suction pressure part. Preferably,
the cultivation water in the water refill tank is fed into the
upper space of the suction pressure part by a drop of the water
level in the suction pressure part caused by replenishment of the
cultivation water by the suction pressure part. The plant
cultivation device preferably includes a water feeder that
communicates with the water refill tank and supplies the
cultivation water to the water replenishing device. The water
feeder preferably has a ballcock.
[0027] [19] The plant cultivation device preferably further
includes another one of the water replenishing device. The water
refill tank of another one of the water replenishing device
preferably communicates indirectly with the water feeder via the
water refill tank that communicates with the water feeder.
[0028] [20] The culture medium material preferably includes gel
particles containing a fertilizer component.
Advantageous Effects of Invention
[0029] The present invention enables a plant cultivation device to
reduce its dependency on electric power and electric control.
BRIEF DESCRIPTION OF DRAWINGS
[0030] FIG. 1 is an end view of a plant cultivation device
according to one embodiment;
[0031] FIG. 2 is an end view of a plant cultivation device
according to Example 1;
[0032] FIG. 3 is an assembly diagram of a check valve according to
Example 1;
[0033] FIG. 4 is a schematic diagram of a plant cultivation device
according to Example 2;
[0034] FIG. 5 is a perspective view of the plant cultivation device
according to Example 2;
[0035] FIG. 6 is a schematic diagram of a discharge operation of a
pump according to Example 2;
[0036] FIG. 7 is a schematic diagram of a suction operation of the
pump according to Example 2;
[0037] FIG. 8 is a schematic diagram of an operation of a water
replenishing device according to Example 2;
[0038] FIG. 9 is a side view of a water refill tank according to a
variation of Example 2;
[0039] FIG. 10 is a schematic diagram of a culture medium material
supporter according to a variation of Example 2;
[0040] FIG. 11 is a schematic diagram of an expansion process of
the culture medium material according to a variation of Example
2;
[0041] FIG. 12 is a perspective view of a device of a double tank
type according to Example 3;
[0042] FIG. 13 is a perspective view of a device of a multiple tank
type according to Example 4;
[0043] FIG. 14 is a schematic diagram of a plant cultivation device
according to Examples 5 and 6;
[0044] FIG. 15 is a perspective view of a check valve according to
Example 7;
[0045] FIG. 16 is an end view of a pair of check valves according
to Example 7;
[0046] FIG. 17 is an end view of a pair of check valves according
to Example 7;
[0047] FIG. 18 is a schematic diagram of a check valve according to
a reference example;
[0048] FIG. 19 is a schematic diagram of a plant cultivation device
according to Example 8;
[0049] FIG. 20 is an end view of a watering channel according to
Example 8;
[0050] FIG. 21 is a partial cross-sectional view of a watering
channel according to Example 9;
[0051] FIG. 22 is a schematic diagram of a plant cultivation device
according to Example 10; and
[0052] FIG. 23 is a schematic diagram of a culture medium material
according to Example 11.
DESCRIPTION OF EMBODIMENTS
[0053] Embodiments and examples of the present invention will now
be described with reference to the drawings. Constituent elements
that are equivalent to each other in the drawings are given the
same reference numerals to omit redundant description of these
elements. Hatching is partly omitted in end faces of the drawings
for better visibility.
[0054] FIG. 1 shows a device 99, which is a plant cultivation
device according to an embodiment. In the drawing, illustration of
an intersecting point between a water inlet pipe 37 and a
water-sucking pipe 36 is simplified. The device 99 includes a
cultivation tank 19 and a solar heat pump system 32. The solar heat
pump system 32 includes a water tank 30. The water tank 30 supplies
cultivation water to the cultivation tank 19 via a watering channel
38. The water tank 30 suctions the cultivation water from the
cultivation tank 19 via the water-sucking pipe 36.
[0055] Cultivation water herein includes nutrient solutions.
Nutrient solution herein refers to water, to which ions, minerals,
and other nutrients are added as required, and which is suited to
the growth of plants as the plants absorb this nutrient solution
from the roots. Cultivation water herein includes water that
substantially does not contain these nutrients. In the following
description, unless otherwise specified, cultivation water may
sometimes be referred to simply as "water".
[0056] The solar heat pump system 32 shown in FIG. 1 further
includes a heat-collecting part 56. The heat-collecting part 56 has
an air-storage part 57. The air-storage part 57 communicates with
an upper section of the water tank 30. The heat-collecting part 56
presses the surface of the water inside the water tank 30 with air
pressure. The air pressure is generated by the heat-collecting part
56 receiving solar light, or sunlight 93, and heating the air
inside the air-storage part 57.
[0057] The water tank 30 shown in FIG. 1 supplies the water that
has been pressed by the air to a culture medium material 90. The
water tank 30 thus supplies water via the watering channel 38. The
water tank 30 supplies water from above the culture medium material
90 that is arranged inside the cultivation tank 19.
[0058] The heat-collecting part 56 shown in FIG. 1 raises the
surface of the water inside the water tank 30. This rising of the
water level occurs as a result of the heated air being cooled by a
decrease of the sunlight 93. The water tank 30 suctions water from
a bottom section of the cultivation tank 19 via the water-sucking
pipe 36. This suctioning occurs in accordance with the rising of
the water mentioned above.
[0059] As shown in FIG. 1, the solar heat pump system 32 suctions
water from outside the system, raises the water level inside the
system, and discharges the water out of the system. The solar heat
pump system 32 obtains energy necessary for this movement of water
with the heat-collecting part 56. Preferably, the solar heat pump
system 32 does not include an electric pump.
[0060] The solar heat pump system 32 shown in FIG. 1 further
includes a discharge check valve 43 that prevents backflow of the
water supplied from the water tank 30 to the cultivation tank 19.
The solar heat pump system 32 further includes a suction check
valve 41 that prevents backflow of the water suctioned from the
cultivation tank 19 to the water tank 30.
[0061] The device 99 shown in FIG. 1 requires substantially no
manpower for watering. This is because watering can be achieved by
the cycle of sunlight as described above. With the use of the
device 99, plants can be grown at lower cost than common
hydroponics methods. This is because the device 99 hardly relies or
relies less on electric power or electronic control as compared to
devices needed for hydroponics.
Example 1
[0062] FIG. 2 is an end view of a device 100 according to Example
1. In the drawing, illustration of an intersecting point between a
water inlet pipe 37 and a water-sucking pipe 36 is simplified. The
device 100 is a water-circulating plant cultivation device. The
device 100 includes a cultivation tank 19, a pump 29, and a water
replenishing device 59. Water circulates between the cultivation
tank 19 and the pump 29 as will be described later.
[0063] The cultivation tank 19 shown in FIG. 2 has a bottom section
20 and an upper face opening 21. The cultivation tank 19 has a body
part 23 provided as walls. The body part 23 extends from the bottom
section 20 to the upper face opening 21. The body part 23 is
preferably cylindrical. The inner cavity 24 of the cultivation tank
19 consists mainly of the hollow cavity in the center of the body
part 23.
[0064] The cultivation tank 19 shown in FIG. 2 includes a supporter
27. The supporter 27 supports a culture medium material 90. The
culture medium material 90 will be described in detail later. The
supporter 27 is arranged in the inner cavity 24. The supporter 27
is preferably arranged closer to the bottom section 20 than to the
upper face opening 21. This way, the cultivation tank 19 can
accommodate a larger culture medium material 90.
[0065] The filter material 25 shown in FIG. 2 is arranged in the
bottom section 20. The filter material 25 is interposed between the
inner cavity 24 and the water-sucking pipe 36. The filter material
25 is preferably a porous material including zeolite. The filter
material 25 is preferably packed in a mesh bag (not shown). The
upper face 22 of the filter material 25 faces the inner cavity 24.
The filter material 25 may be fixed to the bottom section 20 by the
supporter 27 pressing down on the upper face 22.
[0066] The pump 29 shown in FIG. 2 has a pump chamber 39 and a pair
of check valves 40. The pair of check valves 40 has a suction check
valve 41 and a discharge check valve 43. At least one of the
suction check valve 41 and the discharge check valve 43 is
preferably a gravity check valve. The suction check valve 41 and
discharge check valve 43 may be spring check valves.
[0067] The suction check valve 41 shown in FIG. 2 prevents creation
of a water flow that travels from the inner cavity 31 of the water
tank 30 toward the water-sucking pipe 36 without going through the
cultivation tank 19. The discharge check valve 43 prevents creation
of a water flow that travels from the inner cavity 31 toward the
watering channel 38 without going through the cultivation tank 19.
The suction check valve 41, water tank 30, and discharge check
valve 43 are arranged such that the water flows through the suction
check valve 41, water tank 30, and discharge check valve 43 in this
order.
[0068] At least one of the suction check valve 41 and discharge
check valve 43 shown in FIG. 2 is disposed outside the pump chamber
39. Preferably, both of the suction check valve 41 and discharge
check valve 43 are disposed outside the pump chamber 39. Even more
preferably, the suction check valve 41 and discharge check valve 43
are coupled to each other. Such a pair of check valves 40 can be
replaced easily.
[0069] The pair of check valves 40 shown in FIG. 2 may be a group
of check valves. The group of check valves may include a plurality
of suction check valves 41. The group of check valves may include a
plurality of discharge check valves 43.
[0070] FIG. 3 is an assembly diagram of one example of a pair of
check valves 40. The suction check valve 41 and discharge check
valve 43 may have the same configuration as shown in the drawing.
An end face of the suction check valve 41 before assembly is
represented on the right side of the drawing. An end face of the
discharge check valve 43 after assembly is represented on the left
side of the drawing. Above and below the pair of check valves 40
are shown side faces of respective ends of pipes connected to the
check valves.
[0071] The pair of check valves 40 shown in FIG. 3 includes a base
42, valve members 44a and 44b, and covers 46a and 46b. The base 42
includes valve seats 45a and 45b, rings 47a and 47b, and joints 48a
and 48b. The valve seat 45a and ring 47a of the suction check valve
41 are formed on the upper face of the base 42. The valve seat 45b
and ring 47b of the discharge check valve 43 are formed on the
upper face of the base 42. The rings 47a and 47b surround the valve
seats 45a and 45b, respectively.
[0072] The joint 48a of the suction check valve 41 and the joint
48b of the discharge check valve 43 shown in FIG. 3 are formed on
the lower face of the base 42. The joints 48a and 48b communicate
with the valve seats 45a and 45b, respectively. The valve seats 45a
and 45b have a downwardly tapered funnel-like shape.
[0073] Threads are formed in the base 42 shown in FIG. 3. The
threads are preferably provided on the outer surface of the rings
47a and 47b. The valve members 44a and 44b have a downwardly
tapered conical shape. The valve members 44a and 44b have a
specific gravity larger than that of cultivation water. Preferably,
the specific gravity of the valve members 44a and 44b is larger
than that of pure water. The conical outer surface of the valve
member 44a and the funnel-like inner surface of the valve seat 45a
preferably make tight contact with each other.
[0074] To assemble the pair of check valves 40 shown in FIG. 3, the
valve members 44a and 44b are disposed between the cover 46a and
the valve seat 45a, and between the cover 46b and the valve seat
45b, respectively. The valve members 44a and 44b are received in
the valve seats 45a and 45b through the center of the rings 47a and
47b. Threads are formed in the inner surface of the covers 46a and
46b. Thus the threads of the covers 46a and 46b are mated with the
threads of the rings 47a and 47b.
[0075] These threads noted above allow the covers 46a and 46b shown
in FIG. 3 to be removably mated with the rings 47a and 47b.
Accordingly, the suction check valve 41 and discharge check valve
43 can be produced in an efficient manner. The covers 46a and 46b
can be removed from the base 42 by loosening the threads.
Therefore, the valve members 44a and 44b and valve seats 45a and
45b can be cleaned.
[0076] The arrows in FIG. 3 indicate the directions of water flows
83 and 84 coming in and out of the pair of check valves 40. The
water inlet pipe 35 connects to the cover 46a of the suction check
valve 41. Water is fed from the cover 46a to the water inlet pipe
35. The water-sucking pipe 36 connects to the joint 48a. Water is
fed from the water-sucking pipe 36 to the joint 48a. Therefore, a
water flow 84 is created, which travels from the water-sucking pipe
36 shown in FIG. 2 toward the water tank 30, and thus the water is
suctioned from the cultivation tank 19.
[0077] When the water tries to flow in the opposite direction from
that of the water flow 84 shown in FIG. 3, the valve member 44a
makes surface contact with the valve seat 45a and stops the water.
Even when there is no such water flow, the valve member 44a sinks
by gravity and makes surface contact with the valve seat 45a to
stop the water. In addition, the valve member 44a and the valve
seat 45a make tight contact with each other because of the pressure
of the cultivation water whose surface has been pressed by the
heat-collecting part inside the water tank exceeding the pressure
of the cultivation water inside the water-sucking pipe 36. As the
valve member 44a and the valve seat 45a make tight contact, water
leakage from the water tank 30 to the water-sucking pipe 36 is
prevented.
[0078] The water inlet pipe 37 connects to the joint 48b of the
discharge check valve 43 shown in FIG. 3. Water is fed from the
water inlet pipe 37 to the joint 48b. The pipe that forms the
watering channel 38 connects to the cover 46b. Water is fed from
the cover 46b to the watering channel 38. Therefore, a water flow
83 is created, which travels from the water tank 30 shown in FIG. 2
toward the watering channel 38, and thus the water is discharged
into the cultivation tank 19.
[0079] When the water tries to flow in the opposite direction from
that of the water flow 83 shown in FIG. 3, the valve member 44b
makes surface contact with the valve seat 45b and stops the water.
Even when there is no such water flow, the valve member 44b sinks
by gravity and makes surface contact with the valve seat 45b to
stop the water. In addition, the valve member 44b and the valve
seat 45b make tight contact with each other because of the pressure
of the cultivation water whose surface has been raised by the
heat-collecting part inside the water tank falling below the
pressure of the cultivation water inside the watering channel 38.
As the valve member 44b and the valve seat 45b make tight contact,
water leakage from the watering channel 38 to the water tank 30 is
prevented.
[0080] The discharge check valve 43 shown in FIG. 3 is detachable
for the water inlet pipe 37 and watering channel 38. The suction
check valve 41 is detachable for the water inlet pipe 35 and
water-sucking pipe 36. Therefore, the suction check valve 41 and
discharge check valve 43 are readily replaced. If the suction check
valve 41 and discharge check valve 43 are separate components, the
suction check valve 41 and discharge check valve 43 can be
individually replaced.
[0081] Referring back to FIG. 2, the pump chamber 39 shown in FIG.
2 has the water tank 30 and an air tank 50. The water tank 30 has a
sealing plug 33 and an air feed pipe 53. The inner cavity 31 of the
water tank 30 and the inner cavity 51 of the air tank 50
communicate with each other via the air feed pipe 53. The inner
cavity 31 and inner cavity 51 shown in FIG. 2 may be connected
without the air feed pipe 53 and they may for example form a single
space. This example is represented in FIG. 1 described above.
[0082] The water tank 30 shown in FIG. 2 is connected to the
suction check valve 41 and discharge check valve 43. The pump 29
includes the water inlet pipes 35 and 37 mentioned above. One end
of the water inlet pipe 35 connects to the discharge side of the
suction check valve 41. One end of the water inlet pipe 37 connects
to the suction side of the discharge check valve 43. The other ends
of the water inlet pipes 35 and 37 connect to the inner cavity
31.
[0083] The air tank 50 shown in FIG. 2 functions similarly to the
heat-collecting part 56 shown in FIG. 1. The air tank 50 has a
heat-collecting surface 52. The heat-collecting surface 52 is a
surface that collects the solar heat. The heat-collecting surface
52 absorbs the solar heat, and thus can release heat into the inner
cavity 51. The heat-collecting surface 52 may be positioned on the
outer surface of the air tank. The solar heat reaches the
heat-collecting surface as solar rays or solar heat waves. These
will be hereinafter referred to simply as solar heat.
[0084] The air tank 50 shown in FIG. 2 has a container 54 and a
heat-collecting body 55. The container 54 functions similarly to
the air-storage part 57 shown in FIG. 1. The inner cavity of the
container 54 is the inner cavity 51. The heat-collecting body 55
has the heat-collecting surface 52. The heat-collecting body 55 is
positioned in the inner cavity 51. The container 54 in this case is
partly or entirely transparent. The heat-collecting body 55
contacts the air inside the inner cavity 51. Thus the air tank 50
can heat the air inside the air tank 50 efficiently.
[0085] If the container 54 shown in FIG. 2 is transparent, the
heat-collecting surface 52 may be positioned on the inner surface
of the container 54 (not shown). The heat-collecting surface 52 may
be positioned on the outer surface of the container 54 (not shown).
The heat-collecting surface 52 in this case may receive solar heat,
solar rays, or solar heat waves that have transmitted through the
transparent container 54.
[0086] The device 100 shown in FIG. 2 includes the water-sucking
pipe 36 and watering channel 38 mentioned above. The water-sucking
pipe 36 connects the bottom section 20 of the cultivation tank 19
with the suction check valve 41 of the pump 29. The water-sucking
pipe 36 connects to the suction side of the suction check valve
41.
[0087] The watering channel 38 shown in FIG. 2 extends from the
discharge check valve 43 of the pump 29 as far as to reach the
upper face opening 21 of the cultivation tank 19. The watering
channel 38 connects to the discharge side of the discharge check
valve 43. The watering channel 38 may extend from the discharge
check valve 43 as far as to reach the inner cavity 24. The pump
chamber 39 is made airtight by closing the sealing plug 33 and the
pair of check valves 40.
[0088] The water replenishing device 59 shown in FIG. 2 connects to
the bottom section 20 of the cultivation tank 19. The water
replenishing device 59 replenishes water to the cultivation tank
19. The water replenishing device 59 has a water refill tank 60 and
a suction pressure tank 70. The suction pressure tank 70 forms a
suction pressure part. The water refill tank 60 includes a refill
port 63, a discharge pipe 65, and a water level indicator 67. A
cock is provided to the discharge pipe 65.
[0089] The suction pressure tank 70 shown in FIG. 2 has an outer
shell 72 and a sealing plug 73. The suction pressure tank 70 has a
suction pressure chamber 71. The suction pressure chamber 71 is
surrounded by the outer shell 72. The suction pressure chamber 71
can be kept airtight by introducing water therein and closing the
sealing plug 73.
[0090] The water replenishing device 59 shown in FIG. 2 further has
a water refill tube 75. The water refill tube 75 connects the inner
cavity 61 of the water refill tank 60 with the suction pressure
chamber 71. The water refill tube 75 is preferably connected to the
top or near the top of the suction pressure chamber 71. The water
refill tube 75 preferably feeds the water stored in the water
refill tank 60 into an upper space of the suction pressure tank 70.
The filter material 25 is interposed between the inner cavity 24 of
the cultivation tank 19 and the suction pressure chamber 71. The
suction pressure tank 70 replenishes water to the cultivation tank
19 via the filter material 25.
[0091] The water replenishing device 59 shown in FIG. 2 further has
an adjuster 78. The adjuster 78 is provided to the water refill
tube 75. The cross-sectional area of the water flow path inside the
adjuster 78 can be changed freely by operating the adjuster 78. The
adjuster 78 therefore can adjust the flow rate of the cultivation
water inside the water refill tube 75. The adjuster 78 may be a
valve, or a cock. By adjusting the flow rate of the cultivation
water, the water level in the cultivation tank 19 can be made
optimal in accordance with the types of the plants or external
environment.
[0092] The water refill tube 75 may have flexibility in the portion
where the adjuster 78 is provided. The water refill tube 75 may be
made of elastomer. In this case, the adjuster 78 may be a clamp. A
roller clamp is preferable. A roller clamp can change the
cross-sectional area of the inner cavity of the water refill tube
75 to a given size by compressing the water refill tube 75. The
roller clamp, as the adjuster 78, therefore can adjust the flow
rate of the cultivation water inside the water refill tube 75.
[0093] The water replenishing device 59 shown in FIG. 2 may not
include the adjuster 78. In this case, the inner cavity of the
water refill tube 75 need to have an appropriate cross-sectional
area. For example, the cross-sectional area of the inner cavity of
the water refill tube 75 may be set smaller than the
cross-sectional area of the inner cavity of the watering channel
38.
[0094] The suction pressure tank 70 shown in FIG. 2 is separate
from the cultivation tank 19. Therefore, the device 100 may further
include a water supply pipe 77. The water supply pipe 77 connects
the bottom section 20 of the cultivation tank 19 with the suction
pressure chamber 71. The suction pressure tank 70 and the
cultivation tank 19 may be integral with each other as will be
shown in the examples below.
Example 2
[0095] FIG. 4 is a schematic diagram of a device 101, which is a
plant cultivation device according to Example 2. In the device 101,
the cultivation tank 19 is located inside the suction pressure tank
70. The body part 23 of the cultivation tank 19 constitutes part of
the walls of the suction pressure chamber 71. In other words, the
suction pressure tank 70 and cultivation tank 19 are integrated,
sharing the walls. The suction pressure chamber 71 may laterally
surround the cultivation tank 19.
[0096] The filter material 25 shown in FIG. 4 extends to the bottom
section of the suction pressure chamber 71. In this example,
therefore, the water supply pipe 77 shown in FIG. 1 has been
removed. In other words, the water replenishing device 59 is
connected to the cultivation tank 19 via the filter material 25.
The suction pressure tank 70 has an outer shell 72. The space
surrounded by the outer shell 72, body part 23, and filter material
25 forms the suction pressure chamber 71.
[0097] In the device 101 shown in FIG. 4, the pair of check valves
40 is arranged inside the water tank 30. Therefore, the water inlet
pipes 35 and 37 shown in FIG. 1 may be omitted. In the device 101,
the cultivation tank 19, water tank 30, suction pressure tank 70,
and water refill tank 60 are integrated. The air tank 50 only is
separate from these. The air tank 50 is preferably provided outside
the device 101 because of the need to receive the sunlight.
[0098] FIG. 5 is a perspective view of the device 101. Some
components are omitted. The components other than the air tank 50
are integrated such as to surround the cultivation tank 19. The
device 101 can easily be designed to have a smaller volume than
that of the device 100 shown in FIG. 1. The plant cultivation
device can therefore be transported and installed as a unit.
[0099] Since the pump chamber 39 shown in FIG. 4 includes an air
feed pipe 53, the air tank 50 can be separated from the water tank
30. Therefore, as shown in FIG. 5, the air tank 50 can readily be
installed at a position where the sunlight 93 can be easily
received. The air tank 50 may be distanced from other components on
a plane, for example. The air feed pipe 53 may be curved at 90
degrees or more as shown in FIG. 5. The air feed pipe 53 may have
sufficient flexibility so that such bending is possible.
[0100] A method of cultivating plants with the use of the device
101 shown in FIGS. 4 and 5 will be shown below. First, as shown in
FIG. 4, the water tank 30 and cultivation tank 19 are filled with
water. The portions with fine horizontal hatching in the drawing
represent the presence of water. This applies also to other
drawings. The sealing plug 33 is opened when water is poured into
the water tank 30. Water is poured into the inner cavity 31 through
the open sealing plug 33. After that, the sealing plug 33 is shut
to make the pump chamber 39 airtight.
[0101] The culture medium material 90 shown in FIG. 4 is preferably
a material 90 that contains a water-absorbent compressed material
as shown in FIG. 5 before use. The water-absorbent compressed
material may be a dried natural material. The water-absorbent
compressed material preferably expands when immersed in water by
absorbing the water.
[0102] The properties of the water-absorbent compressed material
are not specifically limited. The properties are preferably
selected from the viewpoints of water retainability, air and water
permeabilities, and high swelling efficiency. From these
viewpoints, fibrous substances can be named as one example. Fibrous
substances include plant fibers, and mineral fibers such as rock
wool. Alternatively, the water-absorbent compressed material may be
made of a vegetable fertilizer. Vegetable fertilizers are
advantageous in that nitrogen deficiency can hardly occur in the
culture medium material 90 as compared to immature plant fibers,
for example. This is because the fibrous substances have been well
decomposed in vegetable fertilizers.
[0103] The culture medium material 90 shown in FIG. 5 has been
dried, so that it is lightweight and can be easily stored. The
culture medium material 90 is compressed, too, so that it can be
readily transported. Preferably, therefore, the culture medium
material 90 is produced beforehand, with compositions suitable for
the plant cultivation method according to this example, stored,
transported to a cultivation site, and unpackaged at the
cultivation site as required.
[0104] The culture medium material 90 before use is preferably
packed in a capsule 89 as shown in FIG. 5. The capsule 89 functions
as a package material of the culture medium material 90. Packaging
in capsules 89 promotes embodiment of this method even in areas
where suitable water-absorbent compressed materials are not
available.
[0105] The culture medium material 90 is taken out of the capsule
89 as shown in FIG. 5. The culture medium material 90 has been
compressed and has its volume reduced. Therefore, this culture
medium material 90 can be easily inserted into the inner cavity of
the cultivation tank 19 from the upper face opening of the
cultivation tank 19. Since the culture medium material 90 is a
water-absorbent compressed material, its volume increases when
immersed in water as shown in FIG. 4. For cultivation of plants,
the culture medium material is let swell until the culture medium
material 90 abuts on the inner wall surface of the cultivation tank
19.
[0106] Referring back to FIG. 4, seeds 91 of a desired type of
plant are sown on the upper face of the culture medium material 90
shown in FIG. 4. One or more types of seeds 91 can be sown on the
culture medium material 90. The seeds 91 may be covered with a
culture medium material of the same composition as that of the
culture medium material 90, soil, or other culture medium
materials. The plants are thus cultivated on the upper face of the
culture medium material 90.
[0107] Instead of the seeds 91 shown in FIG. 4, young plants,
seedlings, cuttings, bulbs, or other plant tissues of desired types
of plants may be planted. The plant may be a vegetable, or a fruit.
The vegetable can be any of root vegetables, leaf vegetables, stem
vegetables, flower vegetables, and fruit vegetables. Fruit
vegetables include tomatoes, cucumbers, and eggplants, but are not
limited to these.
[0108] Sunlight 93 is directed to the heat-collecting surface 52
shown in FIG. 5. This can be done by setting the air tank 50 or the
device 101 under the sunlight 93. The heat-collecting surface 52
receives the solar heat as mentioned above. During the day, the
heat-collecting surface 52 receives the sunlight 93 and collects
heat. During the night, the heat-collecting surface 52 does not
receive the sunlight 93, so it does not collect heat. Heat
collection by the heat-collecting surface 52 thus fluctuates in
daily cycles. While affected by the latitude and weather
conditions, the collected heat fluctuations in daily cycles go on
without requiring man-made power.
[0109] FIG. 6 is a schematic diagram of a discharge operation of
the pump 29. In the drawing, the water refill tank, which is part
of the water replenishing device, is omitted. The drawing shows the
device 101 during the day. When the sunlight 93 reaches the
heat-collecting surface 52 during the day, the heat-collecting
surface 52 receives the solar heat.
[0110] The heat-collecting body 55 shown in FIG. 6 gives away the
thermal energy received by the heat-collecting surface 52 to the
surrounding air. The thermal energy raises the temperature, as well
as pressure, of the air inside the inner cavity 51. The container
54 at this time does not undergo a significant deformation because
of a difference in pressure between inside and outside of the
container 54. Therefore, pressure rise 81 from the level before the
reception of the sunlight 93 occurs inside the air tank 50.
[0111] As shown in FIG. 6, the water tank 30 is filled with water.
The pressure rise 81 travels through the air feed pipe 53 to the
water tank 30. Pressure 85 acts to press down the water surface
inside the water tank 30. In other words, the pressure of the water
whose surface has been pressed by the air tank 50 inside the water
tank 30 exceeds the pressure of the water inside the watering
channel 38.
[0112] Accordingly, when the pressure 85 shown in FIG. 6 acts on
the water, the valve member 44b is pushed up. This cancels the
tight contact between the valve member 44b and the valve seat 45b.
The valve member 44b and the valve seat 45b separate further from
each other. Then, an upward water flow 83 is created in the
discharge check valve 43. In other words, the watering channel 38
is opened.
[0113] On the other hand, water tries to flow downward in the
suction check valve 41 shown in FIG. 6. However, since the valve
member 44a is in tight contact with the valve seat 45a, the water
is stopped. In other words, the water-sucking pipe 36 is shut.
Therefore, the water flow 83 is predominantly generated and the
pump 29 can carry out the desired discharge operation. In other
words, the water inside the water tank 30 is fed to the cultivation
tank 19 through the watering channel 38. No water flow is created
in the water-sucking pipe 36.
[0114] When the valve member 44b shown in FIG. 6 is pushed up, the
water flow 83 reaches the watering channel 38. The water inside the
water tank 30 eventually flows out from the distal end of the
watering channel 38 and drops onto the upper face opening 21 of the
cultivation tank 19. The water falls through and onto the upper
face of the culture medium material 90. As the water contacts the
air, oxygen is dissolved in the water.
[0115] The seedling 92 shown in FIG. 6 has been germinated from the
seed 91 shown in FIG. 4 and grown. The water inside the water tank
30 is irrigated to the culture medium material 90 through the
watering channel 38. The roots of the seedling 92 absorb the water
from the culture medium material. Thus the seedling 92 can actively
transpire as it receives the sunlight 93 during the day.
[0116] As described above, the device 101 shown in FIG. 6 can speed
up the growth of the seedling 92. The device 101 can provide this
function without receiving power supply or electronic control.
[0117] As the water flow 83 shown in FIG. 6 is created, the water
in the water tank 30 is decreased. This increases the air volume in
the air tank 50 and in the water tank 30. The increase in air
volume reduces the pressure rise 81, so that the pressure 85 is
decreased.
[0118] When the pressure 85 shown in FIG. 6 is reduced, the
pressure 85 soon comes to counterbalance the atmospheric pressure,
pump head pressure, and pressure losses in the discharge check
valve 43 and in the watering channel 38. When this happens and the
water flow 83 stops, the valve member 44b goes down by gravity and
makes surface contact with the valve seat 45b. Thus generation of a
water flow in the opposite direction from the water flow 83 is
prevented.
[0119] FIG. 7 is a schematic diagram of a suction operation of the
pump 29. In the drawing, the water refill tank, which is part of
the water replenishing device, is omitted. The drawing shows the
device 101 during the night. The heat-collecting surface 52 does
not receive solar heat during the night. When the temperature of
the atmosphere is lower than that of the heat-collecting surface
52, radiation heat 94 is released to the atmosphere.
[0120] The heat-collecting body 55 that has released heat from the
heat-collecting surface 52 shown in FIG. 7 is cooled down. The
heat-collecting body 55 takes in thermal energy from the air in the
inner cavity 51. The temperature of the air in the inner cavity 51
drops, and so does the pressure. Therefore, pressure reduction 82
from the level before the reception of the sunlight 93 occurs
inside the air tank 50.
[0121] As shown in FIG. 7, the water tank 30 is filled with water.
The pressure reduction 82 travels through the air feed pipe 53 to
the water tank 30. Pressure 86 acts to raise the water level inside
the water tank 30. In other words, the pressure of the water whose
surface has been raised by the air tank 50 inside the water tank 30
falls below the pressure of the cultivation water inside the
water-sucking pipe 36.
[0122] Accordingly, when the pressure 86 shown in FIG. 7 acts on
the water, the valve member 44a is pushed up. This cancels the
tight contact between the valve member 44a and the valve seat 45a.
The valve member 44a and the valve seat 45b separate further from
each other. This creates an upward water flow 84 in the suction
check valve 41. In other words, the water-sucking pipe 36 is
opened.
[0123] On the other hand, water tries to flow downward in the
discharge check valve 43 shown in FIG. 7. However, since the valve
member 44b is in tight contact with the valve seat 45b, the water
is stopped. In other words, the watering channel 38 is shut.
Therefore, the water flow 84 is predominantly generated and the
pump 29 can carry out the desired suction operation. In other
words, the water inside the cultivation tank 19 is fed through the
water-sucking pipe 36 in accordance with the rising of the water
inside the water tank 30. No water flow is created in the watering
channel 38.
[0124] When the valve member 44a shown in FIG. 7 is pushed up, the
water flow 84 connects to the water-sucking pipe 36. Water is drawn
from the culture medium material 90 through the bottom section 20
into the water-sucking pipe 36. The water inside the culture medium
material 90 moves toward the bottom section 20 by gravity or
capillary action. Since no water flow is created in the watering
channel 38 during the night as described above, no water is
supplied from the water tank 30 to the cultivation tank 19.
[0125] As shown in FIG. 7, fresh air 87 is supplied through the
upper face opening 21 into the culture medium material 90, from
which the water has been sucked away as described above. This
brings about aerobic conditions in the culture medium material 90
and promotes bacterial nitrification in the culture medium material
90. The water passes through the filter material 25 positioned in
the bottom section 20. The filter material 25 filters wastes from
the water and purifies the water. The filter material 25 may also
exchange ions with the water.
[0126] As described above, the device 101 shown in FIG. 7 can
improve the soil environment in the culture medium material 90. The
device 101 can provide this function without receiving power supply
or electronic control.
[0127] As the water flow 84 shown in FIG. 7 is created, the water
in the water tank 30 is increased. The volume of the air inside the
pump chamber 39 is therefore decreased. The increase in air volume
reduces the pressure reduction 82, so that the pressure 86 is
decreased.
[0128] When the pressure 86 shown in FIG. 7 is reduced, the
pressure 86 soon comes to counterbalance the atmospheric pressure,
pump head pressure, and pressure losses in the suction check valve
41 and in the water-sucking pipe 36. When this happens and the
water flow 84 stops, the valve member 44a goes down by gravity and
makes surface contact with the valve seat 45a. Thus generation of a
water flow in the opposite direction from the water flow 84 is
prevented.
[0129] As shown in FIGS. 6 and 7, the pump 29 repeatedly supplies
water from the water tank 30 to the cultivation tank 19 and
receives water from the cultivation tank 19 to the water tank 30 in
cycles. The device 101 thus functions as a water-circulating plant
cultivation device. This cyclic supplying and receiving of water
relies on the daily cycles of fluctuations in the heat collected by
the heat-collecting surface 52. Thus the device 101 can provide
this water-circulating function without receiving power supply or
electronic control.
[0130] The pump 29 shown in FIG. 7 may carry out the suction
operation not only during the night but also when the sun is
blocked by clouds. The seedling 92 transpires less actively when
the sun is blocked by clouds. Therefore, the culture medium
material 90 can have a lower water content than when there is
sunlight. The device 101 is therefore suited to controlling the
water content of the culture medium material 90 in accordance with
the amount of sunlight.
[0131] Next, the water supply operation of the water replenishing
device 59 will be described with reference to FIG. 8. In FIG. 8,
the pump and components connected thereto are omitted.
[0132] First, the significance of the water replenishing device 59
shown in FIG. 8 will be explained. As has been shown in FIG. 6, the
seedling 92 absorbs the water in the culture medium material 90 and
releases the water content to the atmosphere by transpiration. Thus
the water is lost from the circulation system consisting of the
cultivation tank 19 and the pump 29 shown in FIGS. 6 and 7.
[0133] When the seed 91 is sown, the water refill tank 60 is filled
with water, as shown in FIG. 4. The suction pressure chamber 71 is
airtightly sealed. The water replenishing device 59 keeps
replenishing the water in the water refill tank 60 to the
circulation system mentioned above. The water replenishing period
is longer than one daily cycle of supplying and receiving water by
the pump 29.
[0134] The young plant 95 shown in FIG. 8 has grown from the
seedling 92 shown in FIG. 6. Preferably, the water replenishing
device 59 keeps replenishing water to the circulation system until
the seed 91 shown in FIG. 4 grows into the young plant 95 shown in
FIG. 8, and until the young plant 95 bears fruit ready for harvest.
This period shall be referred to as cultivation period. Water
consumption during the cultivation period appears as a water level
drop 68.
[0135] The water level in the inner cavity 61 of the water refill
tank 60 shown in FIG. 8 is higher than the water level in the inner
cavity 24 of the cultivation tank 19. This water level difference
26 causes the water in the water refill tank 60 to flow toward the
cultivation tank 19. This indicates that there is a certain level
of water pressure, or a water pressure difference. This water
pressure or water pressure difference shall be referred to as
"pressure loss". The pressure loss between the water refill tank 60
and the cultivation tank 19 propagates indirectly through the
suction pressure chamber 71.
[0136] The suction pressure chamber 71 shown in FIG. 8 is
airtightly sealed as mentioned above. As the suction pressure tank
70 replenishes water to the cultivation tank 19, the water level of
the suction pressure chamber 71 goes down. When the water level of
the suction pressure chamber 71 lowers, the volume of the air 74
expands. The pressure of the air 74 is thus reduced.
[0137] When the pressure of the air 74 shown in FIG. 8 is reduced,
suction pressure is applied to the opening 76 of the water refill
tube 75 that faces the suction pressure chamber 71. Thus the water
inside the water refill tube 75 progresses into the suction
pressure chamber 71 from the opening 76. In other words, the water
inside the water refill tank 60 is fed into the upper space of the
suction pressure tank 70. This water drops down onto the water
surface in the suction pressure chamber 71. This way, the water
level that has lowered recovers. The volume of the air 74 returns
to its original level. Thus the pressure of the air 74
recovers.
[0138] When the water inside the water refill tube 75 shown in FIG.
8 moves into the suction pressure chamber 71 from the opening 76,
the volume of the air 74 reduces. The pressure of the air 74 thus
rises. Thus water pressure is applied to the filter material 25
that faces the suction pressure chamber 71. There is created a
water pressure difference in the filter material 25 between the
suction pressure chamber 71 side and the cultivation tank 19 side.
Due to the pressure loss in the filter material 25, not all the
pressure difference propagates to the cultivation tank 19.
Therefore, the water flows from the suction pressure chamber 71
toward the cultivation tank 19 more slowly than when there is no
filter material 25.
[0139] The operation of the suction pressure chamber 71 shown in
FIG. 8 is performed continuously or intermittently without
requiring human control. Namely, the water moves continuously or
intermittently from the water refill tank 60 toward the cultivation
tank 19 by the effects of the pressure loss described above. Water
is replenished from the water refill tank 60 toward the cultivation
tank 19 in a timely manner to make up for the amount lost by
transpiration from the young plant 95 or desiccation from the upper
face of the culture medium material 90.
[0140] The flow rate of the water traveling from the water refill
tank 60 toward the cultivation tank 19 shown in FIG. 8 can be
adjusted by the adjuster 78. As shown in FIG. 7, water is drawn
from the culture medium material 90 through the bottom section 20
into the water-sucking pipe 36. If the flow rate of the water
traveling from the water refill tank 60 toward the cultivation tank
19 is excessive, the culture medium material 90 keeps replenished
with water, so that the water cannot be sucked away from the
culture medium material 90.
[0141] Meanwhile, as shown in FIG. 6, water is supplied from the
watering channel 38 irrespective of the water content of the
culture medium material 90. Therefore, there may be cases where the
total amount of water supplied to the culture medium material 90
shown in FIG. 8 is excessive. This is where the adjuster 78 helps
control the total amount of water supplied to the culture medium
material 90.
[0142] As shown in FIGS. 6 and 7, the water level in the
cultivation tank 19 varies in daily cycles. Therefore, the pressure
loss varies in daily cycles. The water level difference 26 may be
considered as a difference between an average water level per day
in the cultivation tank 19 and the water level of the water refill
tank 60. The pressure loss remains constant throughout the
cultivation period.
[0143] For example, when a water level drop 68 is observed in the
water refill tank 60 shown in FIG. 8, the average water level in
the cultivation tank 19 is also reduced. As the average water level
in the cultivation tank 19 decreases, the roots of the young plant
95 grow deep down into the culture medium material 90. The roots
may reach the filter material 25. The roots may even extend through
the filter material 25. With the roots extended long into the
culture medium material 90, the young plant 95 can better absorb
nutrients.
[0144] In the water replenishing device 59 shown in FIG. 8,
backflow of the water can hardly ever happen. This is because the
air 74 that has a certain volume separates the opening 76 and the
water surface of the suction pressure chamber 71. That the opening
76 is smaller than the water surface of the suction pressure
chamber 71 also contributes to this. Namely, it is attributed to
the fact that, based on Pascal's law, the force required for
pressing the water in the water refill tube 75 from the suction
pressure chamber 71 side to flow reversely is much larger than the
force required for pressing down the water surface of the suction
pressure chamber 71.
[0145] The plant cultivation method according to the example has
been described above with reference to FIGS. 4 to 8. This method
provides the following advantages in cultivating plants. The
following advantages can also be enjoyed with the use of devices
according to other embodiments or examples.
[0146] First, the method according to the example enables the use
of organic fertilizers. This is an advantage not available in
common hydroponics. Organic fertilizer contains a large amount of
microorganisms including harmful bacteria and is difficult to use
in hydroponics. In the method according to the example, the air is
introduced periodically into the culture medium material so that
the micro-organic balance in the culture medium material can be
kept in conditions suited to the growth of plants.
[0147] Soil may contain plant pathogens or pests, but the plants
grown by the method according to the example will be less affected
by them, because the cultivation tank is separated from the ground.
This is an advantage over soil cultivation.
[0148] With the method according to the example, the cost will not
be too high even if it is performed for a single plant. This is
because, according to the example, growing of plants by watering
during the day, improvement of the soil environment, and continuous
replenishment of water over a cultivation period can be realized
without using electronic control.
[0149] While it is possible to cultivate a single plant in common
hydroponics, too, it is not practical from the viewpoint of
industrial applicability. In common hydroponics, costs are incurred
for electronic control and reduction of harmful bacteria. It is
essential in actuality to reduce the proportion of these costs to
the overall cost of cultivation. No feasible methods have been
found out other than increasing the scale of cultivation to realize
such a cost reduction.
[0150] FIG. 9 is a side view of water refill tanks 62a to 62c
according to a variation example of the device. The structure of
the water refill tanks 62a to 62c is the same as that of the
above-described water refill tank 60 except for the points noted
below. In this variation, the plant cultivation device includes two
or more pairs of cultivation tank and water replenishing device.
Each pair includes the water refill tanks 62a to 62c.
[0151] The water refill tanks 62a to 62c shown in FIG. 9 are
disposed on a step-like base 69. The water refill tanks 62a to 62c
are arranged sequentially from the top. The plurality of water
refill tanks 62a to 62c are arranged stepwise. The water refill
tanks should preferably be arranged such that there is a water
level difference between one water refill tank and another water
refill tank.
[0152] The device shown in FIG. 9 includes one water supply
passage, or two or more water supply passages, instead of the
discharge pipe 65 mentioned above. In this variation, the device
includes water supply passages 64a to 64c. The water supply
passages 64b and 64c connect to the side faces of the water refill
tanks 62a and 62b, respectively.
[0153] The water supply passages 64a to 64c shown in FIG. 9 each
extend from a side face of the water refill tank included in one
pair to above the upper face opening of the water refill tank
included in another pair. Namely, the water supply passages 64b and
64c respectively extend from the side faces of the water refill
tanks 62a and 62b to above the upper face openings of the water
refill tanks 62b and 62c. Discharge ports 66a to 66c are provided
to the side faces of the water refill tanks 62a to 62c. The water
supply passages 64b and 64c may respectively connect to the
discharge ports 66a and 66b.
[0154] In this variation example, the water supply passages 64a to
64c are provided as water supply means to upper-side water refill
tanks. These water supply passages 64a to 64c supply the water in
the upper-side water refill tank(s) to lower-side water refill
tank(s). In this variation example, water can be refilled to all
the water refill tanks by supplying water to the uppermost water
refill tank.
[0155] FIG. 10 is a schematic diagram of cultivation tanks 18a and
18b according to a variation example of the device. The structure
of the cultivation tanks 18a and 18b is the same as that of the
above-described cultivation tank 19 except for the points noted
below. The cultivation tanks 18a and 18b include supporters 28a and
28b, respectively. The supporter 28a has a downwardly tapered,
funnel-like shape, and the supporter 28a has a downwardly tapered,
funnel-like shape.
[0156] In the cultivation tank 19 shown in FIG. 3, the space
between the culture medium material 90 and the upper face 22 of the
filter material 25 is small. When irrigated, therefore, the
cultivation tank 19 is soon fully filled with water. On the other
hand, the supporters 28a and 28b shown in FIG. 10, by their
funnel-like shape, can form some space between the filter material
25 and the bottom part of the culture medium material 90.
[0157] In the cultivation tanks 18a and 18b shown in FIG. 10, the
space between the culture medium material 90 and the upper face 22
of the filter material 25 is larger than that of the cultivation
tank 19 shown in FIG. 3. Therefore, the cultivation tanks 18a and
18b are not fully filled with water soon when irrigated. Namely,
the shape of the supporters 28a and 28b functions to buffer the
rise of the water level.
[0158] The culture medium material 90 before being immersed in
water may have a lower face that is upwardly tapered funnel-like
shape, so that it can be fitted with the supporter 28a shown in
FIG. 10. Or, the culture medium material 90 before being immersed
in water may have a lower face that is downwardly tapered conical
shape, so that it can be fitted with the supporter 28b.
[0159] FIG. 11 is a schematic diagram of an expansion process of
the culture medium material according to a variation example of the
method. The culture medium material 96a that is a water-absorbent
compressed material is immersed in water, to obtain the culture
medium material 96e, after going through various forms of cultural
medium materials 96b to 96d in accordance with the predetermined
expansion process.
[0160] The culture medium material 96a shown in FIG. 11 has an
upper part 97a and a lower part 97b. The lower part 97b has a flat
bottom face. The upper part 97a has an upwardly tapered conical
shape. Therefore, the culture medium material 96a floating on water
has restorability. Namely, the tip of the upper part 97a with a
conical shape, of the culture medium material 96a, appears above
the water surface.
[0161] The culture medium material 96a shown in FIG. 11 has a seed
receiving part 98. The tip of the upper part 97a is formed as the
seed receiving part 98. The material of the seed receiving part 98
has higher water retainability than the material of the main body
of the culture medium material 96a. Therefore, it is well suited to
germination of seeds or watering for seedlings.
[0162] The material of the seed receiving part 98 shown in FIG. 11
preferably has a larger particle size than the material of the main
body of the culture medium material 96a. The seed receiving part 98
preferably contains more clay substances than the main body of the
culture medium material 96a. This way, the seed receiving part 98
has suitable water retainability.
[0163] The seed 91 of a plant is embedded in the seed receiving
part 98 shown in FIG. 11. Therefore, the seed 91 will hardly go
under the water. The culture medium materials 96a to 96e are hard
to tip over. The seed 91 will unlikely come to position under the
culture medium material 96e.
[0164] The culture medium material 96a shown in FIG. 11 has a
conical shape. Therefore, even after the culture medium material
96a has expanded to become the culture medium material 96e, the
seed receiving part 98 is still positioned on the ridge or hill of
the culture medium material. Thus discharge 88 of water from the
seed receiving part 98 can be efficiently performed during the
cultivation of the plant.
Example 3
[0165] FIG. 12 is a perspective view of a device 102 of a double
tank type according to Example 3. Below, the differences between
the device 102 and the device 101 shown in FIG. 5 will be mainly
described. The device includes two cultivation tanks 17a and 17b.
The watering channel 38 extends as far as to the upper face
openings of the cultivation tanks 17a and 17b.
[0166] The device 102 shown in FIG. 12 has one pump. This pump
includes one air tank 50. The pump of the device 102 has one or two
water tanks. The water tank(s) connect(s) to the one air tank 50.
The device 102 has better space efficiency than the device 101.
Example 4
[0167] FIG. 13 is a perspective view of devices 103a to 103c of a
multiple tank type according to Example. Below, the differences
between the devices 103a to 103c and the device 101 shown in FIG.
5, and the device 102 shown in FIG. 9 will be mainly described. The
device 103a includes three or more cultivation tanks.
[0168] For example, the device 103a shown in FIG. 13 includes
cultivation tanks 17a to 17f. The device 103a has one pump. This
pump includes one air tank 50. The pump of the device 103 has one
water tank, or two or more water tanks. The water tank(s)
connect(s) to the one air tank 50. The devices 103b and 103c have
the same structure as that of the device 103a.
[0169] Devices equivalent to the devices 103a to 103c shown in FIG.
13 can be arranged in as large a number as the available land area
permits. Water, on the other hand, need not be supplied every day
to the entire surface of the land for cultivating the plants. The
plants can be grown well only by filling the water refill tanks of
the devices 103a to 103c and other devices just once. Water may be
replenished to the water refill tanks as required.
[0170] Growing plants with the use of the devices 103a to 103c
shown in FIG. 13 requires less water than growing plants planted
directly on the land. This is because the water in the devices 103a
to 103c hardly seeps into the land as ground water. This also
indicates that soil pollution by pesticides can hardly occur even
if pesticides are added to the water circulated in the devices 103a
to 103c. This also applies when other devices mentioned above are
used.
Example 5
[0171] The device 105 shown in FIG. 14 is a plant cultivation
device according to Examples 5 and 6. The device 105 has a water
replenishing device 119 instead of the water replenishing device 59
in Examples 1 and 2 (FIGS. 2 and 4). The water replenishing device
119 has the same structure as that of the water replenishing device
59 except for the following points. The water replenishing device
119 further has a water storage part 130. The water storage part
130 connects to the filter material 25. The water storage part 130
replenishes water to the cultivation tank 19 via the filter
material 25.
[0172] The water replenishing device 119 shown in FIG. 14 has a
suction pressure part 120 and a water supply pipe 127. The suction
pressure part 120 has the same structure as that of the suction
pressure part 70 in Examples 1 and 2 (FIGS. 2 and 4) except for the
following points. The suction pressure part 120 communicates with
the water storage part 130 via the water supply pipe 127. The
suction pressure part 120 can be formed integral with the water
refill tank 60.
[0173] The suction pressure part 120 shown in FIG. 14 is positioned
higher than the water storage part 130. Therefore, the suction
pressure part 120 can feed water to the water storage part 130 by
gravity. Preferably, the suction pressure part 120 has its bottom
face 131 positioned higher than the upper face 132 of the water
storage part 130. The suction pressure part 120 can be disposed in
an upper section of the water refill tank 60. The suction pressure
part 120 feeds water to the filter material 25 via the water
storage part 130.
[0174] In FIG. 14, the water storage part 130 and the cultivation
tank 19 are formed integral with each other. The water storage part
130 and the cultivation tank 19 are divided by the walls of the
body part 23. The water storage part 130 and the cultivation tank
19 may be formed separate from each other. In this case, the water
storage part 130 and the filter material 25 may be connected by
another water supply pipe.
[0175] The suction pressure part 120 shown in FIG. 14 has a suction
pressure chamber 121 inside. The suction pressure chamber 121 is
equivalent to the suction pressure chamber 71 in Examples 1 and 2
(FIGS. 2, 4, and 8) except for the following points. The suction
pressure chamber 121 communicates with the inner cavity of the
water storage part 130 via the water supply pipe 127.
[0176] One end of the water supply pipe 127 shown in FIG. 14
connects to the suction pressure chamber 121. The other end of the
water supply pipe 127 is positioned in the inner cavity of the
water storage part 130. This other end is covered by a porous
material 129. An adjuster 128 is attached to the water supply pipe
127. The adjuster 128 can have the same structure as that of the
adjuster 78 in Examples 1 and 2 (FIGS. 2 and 4).
Example 6
[0177] FIG. 14 also shows the structure of the solar heat pump
system according to Example 6. In the device 105, the pipe
structure for connecting the pair of check valves 40 with the water
tank 30 is different from that of Examples 1 and 2 in the following
points. The device 105 includes a connection pipe 134 and a water
inlet pipe 135. The connection pipe 134 is provided between the
suction check valve 41 and the discharge check valve 43. The
connection pipe 134 connects the suction check valve 41 and the
discharge check valve 43.
[0178] One end of the water inlet pipe 135 connects to a middle
portion of the connection pipe 134 shown in FIG. 14. The other end
of the water inlet pipe 135 connects to the water tank 30. The
water inlet pipe 135 has both functions of the water inlet pipes 35
and 37 in Examples 1 and 2. Namely, during watering, the water
inlet pipe 135 feeds water from the water tank 30 to the connection
pipe 134. When water is suctioned, the water inlet pipe 135 feeds
water from the connection pipe 134 to the water tank 30.
[0179] As shown in FIG. 14, a pressure change of the water inside
the water tank 30 that occurs when the water surface is pressed by
the air tank 50 that functions as a heat-collecting part travels
through the water inlet pipe 135 and the connection pipe 134. The
suction check valve 41 is closed by the pressure of the water in
the connection pipe 134, which is equal to the pressure of the
water in the water tank 30, exceeding the pressure of the water in
the water-sucking pipe 36. Thereby, the water-sucking pipe 36 is
shut.
[0180] As shown in FIG. 14, the discharge check valve 43 is opened
by the pressure of the water in the connection pipe 134, which is
equal to the pressure of the water in the water tank 30, exceeding
the pressure of the water in the watering channel 38. Thereby, the
watering channel 38 is opened. As a result, the water inside the
water tank 30 is fed to the cultivation tank 19 through the
watering channel 38.
[0181] As shown in FIG. 14, a pressure change of the water inside
the water tank 30 that occurs when the water level is raised by the
air tank 50 that functions as a heat-collecting part travels
through the water inlet pipe 135 and the connection pipe 134. The
discharge check valve 43 is closed by the pressure of the water in
the connection pipe 134, which is equal to the pressure of the
water in the water tank 30, falling below the pressure of the water
in the watering channel 38. Thereby, the watering channel 38 is
shut.
[0182] As shown in FIG. 14, the suction check valve 41 is opened by
the pressure of the water in the connection pipe 134, which is
equal to the pressure of the water in the water tank 30, falling
below the pressure of the water in the water-sucking pipe 36.
Thereby, the water-sucking pipe 36 is opened. As a result, the
water is fed from the cultivation tank 19 to the water tank 30
through the water-sucking pipe 36 in accordance with the rising of
the water inside the water tank 30.
Example 7
[0183] FIG. 15 shows a check valve according to Example 7. In this
example, a duck bill or bill-shaped suction check valve 141a shown
in FIG. 15 is used instead of the suction check valve 41 (FIG. 3)
used in Examples 1 and 2. The valve member of the suction check
valve 141a has two lips 144a and 144b that form a bill part. The
bill part has a funnel-like shape that includes the lips 144a and
144b. A base part 147a is provided below the bill part. The base
part 147a has a groove 148a.
[0184] The lips 144a and 144b shown in FIG. 15 have flexibility.
The lips 144a and 144b are preferably made of rubber. The lips 144a
and 144b are preferably curved inward of the valve member. This
structure allows the distal ends of the lips 144a and 144b to make
tight contact with each other easily.
[0185] The valve member of the suction check valve 141a shown in
FIG. 15 has a slit 145a and a notch 146a. The slit 145a and the
notch 146a are both positioned on the upper side that is at the
distal end of the bill part formed by the lips 144a and 144b. The
notch 146a is positioned at the center on the upper side. The upper
side is chamfered at both ends in an arc. The slit 145a is provided
only in the notch 146a. Preferably, the notch 146a has an arcuate
shape.
[0186] FIGS. 16 and 17 show a pair of check valves 140 according to
Example 7. The pair of check valves 140 has a suction check valve
141a and a discharge check valve 143a. The discharge check valve
143a has the same structure as that of the suction check valve
141a.
[0187] A housing 142 shown in FIGS. 16 and 17 is used for disposing
the pair of check valves 140 at predetermined positions inside the
pump. The housing 142 has openings 139a to 139c. The opening 139a
and opening 139b are provided at one end and the other end of the
housing 142, respectively. The opening 139c is provided in a body
part of the housing 142. The body part of the housing 142 functions
as the connection pipe 134 (FIG. 14) in Example 6. The pair of
check valves 140 and housing 142 can be replaced as one integral
unit.
[0188] The suction check valve 141a and discharge check valve 143a
shown in FIGS. 16 and 17 are attached in the inner cavity of the
housing 142. The bill part of the suction check valve 141a is
oriented to the center of the housing 142. The bill part of the
suction check valve 141a is oriented to the opening 139b.
[0189] The housing 142 shown in FIGS. 16 and 17 has protrusions
149a and 149b in the inner cavity. The groove 148a is fitted with
the protrusion 149a. The groove 148b of the discharge check valve
143a is fitted with the protrusion 149b. The base part 147a, and
the base part 147b of the discharge check valve 143a, make tight
contact with these protrusions to stop water leaks.
[0190] FIGS. 16 and 17 show the shape of the suction check valve
141a and discharge check valve 143a when the water pressure is
balanced, or when no water pressure is being applied (hereinafter
referred to as stationary state). In this state, the slit 145a and
the slit 145b of the discharge check valve 143a are preferably
closed.
[0191] As shown in FIGS. 16 and 17, the lips 144a and 144b of the
suction check valve 141a preferably become thinner toward the
distal ends. This structure allows the distal ends of the lips 144a
and 144b to make tight contact with each other easily. The same
applies to the lips of the discharge check valve 143a.
[0192] In FIG. 16, the pressure of the water whose surface has been
pressed by the heat-collecting part inside the water tank is
exceeding the pressure of the water inside the water-sucking pipe
and in the watering channel. Namely, the water pressure in the body
part of the housing 142 is relatively raised. At this time, the
bill part of the suction check valve 141a deforms to make a sharp
angle at the distal end as indicated with reference numeral 141b.
Thus the slit 145a is closed even more tightly than in the
stationary state. Therefore, the water-sucking pipe connecting to
the opening 139a is shut.
[0193] Meanwhile, the bill part of the discharge check valve 143a
shown in FIG. 16 expands so that the distal end is rounded as
indicated with reference numeral 143b. Thus the slit 145b opens in
conformity to the shape of the notch 146b. Since the notch 146b has
an arcuate shape, a hole having an oval cross section is formed.
The watering channel connecting to the opening 139b is thus opened.
As a result, the water inside the water tank is fed to the
cultivation tank through the opening 139c, opening 139b, and
watering channel.
[0194] In FIG. 17, the pressure of the water whose surface has been
pressed by the heat-collecting part inside the water tank is below
the pressure of the water inside the water-sucking pipe and in the
watering channel. Namely, the water pressure in the body part of
the housing 142 is relatively lowered. At this time, the bill part
of the discharge check valve 143a deforms to make a sharp angle at
the distal end as indicated with reference numeral 143c. Thus the
slit 145b is closed even more tightly than in the stationary state.
The watering channel connecting to the opening 139b is thus
shut.
[0195] Meanwhile, the bill part of the suction check valve 141a
shown in FIG. 17 expands so that the distal end is rounded as
indicated with reference numeral 141c. Thus the slit 145a opens in
conformity to the shape of the notch 146a. Since the notch 146a has
an arcuate shape, a hole having an oval cross section is formed.
Therefore, the water-sucking pipe connecting to the opening 139a is
opened. As a result, the water is fed from the cultivation tank to
the water tank through the water-sucking pipe, opening 139a, and
opening 139c in accordance with the rising of the water inside the
water tank.
[0196] FIG. 18 schematically shows a check valve 191 according to a
reference example. The check valve 191 has lips 194a and 194b that
form a bill part. The lips 194a and 194b have straight upper sides.
Abutment surfaces 196a and 196b are formed at the tips of the lips
194a and 194b. The abutment surfaces 196a and 196b form a slit 195
of the check valve 191.
[0197] The abutment surfaces 196a and 196b shown in FIG. 18 are in
tight contact with each other. In conformity therewith, the slit
195 is formed widely on the upper side of the bill part 194.
However, water passes such as to leak through between the abutment
surfaces 196a and 196b. Accordingly, the loss of water pressure is
large. In particular, since it is not actively planned to open the
slit 195 by a suction pressure from outside of the bill shape, the
slit does not easily open when suctioning water.
[0198] In comparison to the reference example described above, the
check valve of the example is characteristic in that it has a notch
in an arcuate shape. Because of this, a large hole is formed in the
upper side of the check valve when the slit opens. The lips that
form the bill part are curved, and become progressively thinner
toward the distal ends. When the slit is closed, the lips therefore
make tight contact with each other in the vicinity of the notch to
shut the hole. Accordingly, the degree of resistance against water
flow is changed significantly between when the hole is open and
when it is closed.
[0199] The check valve of the example responds quickly and operates
uniformly when it opens because of a pressure reduction outside the
bill part, or when it opens because of a pressure rise inside the
bill part, or when it closes because of a pressure rise outside the
bill part, or when it closes because of a pressure reduction inside
the bill part. Thus check valves of the same structure can be
favorably used for both suction check valve and discharge check
valve.
[0200] The duckbill check valve of the example has better
open/close accuracy as compared to the gravity check valves
described in Examples 1 and 2. In other words, they can open and
close highly accurately without depending on the processing
precision of the valve member and the like. Even if foreign
substances get stuck in the check valves, they can still maintain
their open/close accuracy. Therefore, they are also suited to
applications where a bed of nitrifying bacteria is introduced to
the water tank 30, for example. Since the check valve does not use
gravity, there are no variations in opening and closing operations
between when water is irrigated and when water is suctioned. Since
the check valve does not use gravity, the open/close accuracy does
not depend on the attachment accuracy of the check valve. The check
valve can be produced easily as a resin or rubber molded product.
The type or structure of the check valve is not limited as long as
the solar heat pump system operates normally. Namely, both gravity
check valves and duckbill check valves can be used favorably.
Example 8
[0201] FIG. 19 shows a device 106, which is a plant cultivation
device according to Example 8. The device 106 includes two or more
cultivation tanks. In the drawing, the device 106 includes three
cultivation tanks 155a to 155c. The cultivation tanks 155a to 155c
each have the same structure as that of the cultivation tank 19
(FIGS. 2 and 4) described in Examples 1 and 2.
[0202] The device 106 shown in FIG. 19 includes a watering channel
150a. The watering channel 150a has the following characteristics
in addition to those of the watering channel 38 (FIGS. 2 and 4) in
Examples 1 and 2. The watering channel 150a is a duct that has a
distributer 152. A main passage 151 and three branch passages 153a
to 153c connect to the distributer 152. The water flowing through
the watering channel 150a is divided by the distributer.
[0203] The branch passages 153a to 153c shown in FIG. 19 lead to
respective culture medium materials in the cultivation tanks 155a
to 155c. The watering channel 150 is branched so as to distribute
water to each of the cultivation tanks 155a to 155c. The watering
channel 150a enables supplying of water to a plurality of
cultivation tanks with one solar heat pump system. This example is
suited to applications where use of a plurality of relatively small
cultivation tanks is desirable.
Example 9
[0204] FIG. 20 shows a cross-sectional end face of the watering
channel 150a of Example 8 described above. As mentioned above,
there is a time when no water flows through the watering channel
150a. Thus the water is left inside the distributer 152 as an
irregular-shaped pool of water or water drops. This pool of water
causes unevenness in the water flow of the next time watering due
to the strong surface tension of water. Because of this, sometimes
it is difficult to distribute water evenly to each of the branch
passages 153a to 153c.
[0205] FIG. 21 shows a watering channel 150b according to Example
9. The watering channel 150b is different from the watering channel
150a (FIG. 20) in the following point. Sponges 157a to 157c are
mounted to discharge ports 154a to 154c on the cultivation tank
side of the branch passages 153a to 153c of the watering channel
150b. More specifically, water storage chambers 156a to 156c that
have a larger cross-sectional area than that of the discharge ports
154a to 154c are provided. The sponges 157a to 157c are disposed in
each of the water storage chambers 156a to 156c.
[0206] The sponge 157c is appearing in the cross section of the
water storage chamber 156c shown in FIG. 21. As the
water-impregnated sponge 157c serves as a plug, the watering
channel 150 including the distributer 152 is always filled with
water. Formation of water pools in the distributer 152 is thus
prevented. The watering channel 150b is suited to uniform
distribution of water to the branch passages 153a to 153c. The loss
of the pressure generated by the solar heat pump system caused by
the sponges 157a to 157c is small. Therefore they hardly affect the
total flow rate of water.
Example 10
[0207] FIG. 22 shows a device 107, which is a plant cultivation
device according to Example 10.
[0208] The device 107 includes a water feeder 160. The water feeder
160 communicates with the water refill tank 162a of the water
replenishing device via a drain 164a. The water refill tank 162a is
the same as the water refill tank 60 (FIGS. 2, 4, and 14) shown in
Examples 1, 2, and 5.
[0209] The water feeder 160 shown in FIG. 22 includes a ballcock
161. The ballcock 161 is connected to a water supply 159. The water
feeder 160 can keep the water level constant inside the water
refill tank 162a by means of the ballcock 161.
[0210] The device 107 shown in FIG. 22 further includes another
water replenishing device. The other water replenishing device
includes a water refill tank 162b. The water refill tank 162b
communicates with the water refill tank 162a via a drain 164b.
Namely, the water refill tank 162b indirectly communicates with the
water feeder 160 via the water refill tank 162a. Thus water can be
supplied to a plurality of water refill tanks 162a and 162b with
one water feeder 160, and also the water level can be kept constant
in these tanks. A series of water refill tanks can be connected
together in a chain, using other drains including a drain 164c. The
approach of this example wherein water refill tanks indirectly
communicate with the water feeder is suited to larger scale plant
cultivation devices.
Example 11
[0211] FIG. 23 shows a culture medium material 166. The culture
medium material 166 has gel particles 167. The gel particles 167
contain fertilizer components. The gel particles 167 are dispersed
in the culture medium material 166. The gel particles release the
fertilizer components slowly over a long period of time. Fertilizer
components include nitrogen, potassium, and the like. Gel particles
are preferably made of gelatin.
[0212] While the present invention has been described with
reference to embodiments, the present invention shall not be
limited by the above description. Various changes that can be
understood by a person skilled in the art can be made to the
configurations and details of the present invention within the
scope of the invention.
REFERENCE SIGNS LIST
[0213] 17a to 17f Cultivation tank [0214] 18a, 18b Cultivation tank
[0215] 19 Cultivation tank [0216] 20 Bottom section [0217] 21 Upper
face opening [0218] 22 Upper face [0219] 23 Body part [0220] 24
Inner cavity [0221] 25 Filter material [0222] 26 Water level
difference [0223] 27 Supporter [0224] 28a, 28b Supporter [0225] 29
Pump [0226] 30 Water tank [0227] 31 Inner cavity [0228] 32 Solar
heat pump system [0229] 33 Sealing plug [0230] 35 Water inlet pipe
[0231] 36 Water-sucking pipe [0232] 37 Water inlet pipe [0233] 38
Watering channel [0234] 29 Pump chamber [0235] 40 Pair of check
valves [0236] 41 Suction check valve [0237] 42 Base [0238] 43
Discharge check valve [0239] 44a, 44b Valve member [0240] 45a, 45b
Valve seat [0241] 46a, 46b Cover [0242] 47a, 47b Ring [0243] 48a,
48b Joint [0244] 50 Air tank [0245] 51 Inner cavity [0246] 52
Heat-collecting surface [0247] 53 Air feed pipe [0248] 54 Container
[0249] 55 Heat-collecting body [0250] 56 Heat-collecting part
[0251] 57 Air-storage part [0252] 59 Water replenishing device
[0253] 60 Water refill tank [0254] 61 Inner cavity [0255] 62a to
62c Water refill tank [0256] 63 Refill port [0257] 64a to 64c Water
supply passage [0258] 65 Discharge pipe [0259] 66a to 66c Discharge
port [0260] 67 Water level indicator [0261] 68 Water level drop
[0262] 69 Base [0263] 70 Suction pressure tank [0264] 71 Suction
pressure chamber [0265] 72 Outer shell [0266] 73 Sealing plug
[0267] 74 Air [0268] 75 Water refill tube [0269] 76 Opening [0270]
77 Water supply pipe [0271] 78 Adjuster [0272] 81 Pressure rise
[0273] 82 Pressure reduction [0274] 83, 84 Water flow [0275] 85, 86
Pressure [0276] 87 Fresh air [0277] 88 Discharge [0278] 89 Capsule
[0279] 90 Culture medium material [0280] 91 Seed [0281] 92 Seedling
[0282] 93 Sunlight [0283] 94 Radiation heat [0284] 95 Young plant
[0285] 96a to 96e Culture medium material [0286] 97a Upper part
[0287] 97b Lower part [0288] 98 Seed receiving part [0289] 99, 100
to 102, 103a to 103c Device [0290] 105-107 Device [0291] 119 Water
replenishing device [0292] 120 Suction pressure part [0293] 121
Suction pressure chamber [0294] 127 Water supply pipe [0295] 128
Adjuster [0296] 129 Porous material [0297] 130 Water storage part
[0298] 131 Bottom face [0299] 132 Upper face [0300] 134 Connection
pipe [0301] 135 Water inlet pipe [0302] 135 Water inlet pipe [0303]
139a to 139c Opening [0304] 140 Pair of check valves [0305] 141a to
141c Suction check valve [0306] 142 Housing [0307] 143a to 143c
Discharge check valve [0308] 144a, 144b Lip [0309] 145a, 145b Slit
[0310] 146a, 146b Notch [0311] 147a, 147b Base part [0312] 148a,
148b Groove [0313] 149a, 149b Protrusion [0314] 150 Watering
channel [0315] 151 Main passage [0316] 152 Distributer [0317] 153a
to 153c Branch passage [0318] 154a to 154c Discharge port [0319]
155a to 155c Cultivation tank [0320] 156a to 156c Water storage
chamber [0321] 157a to 157c Sponge [0322] 159 Water supply [0323]
160 Water feeder [0324] 161 Ballcock [0325] 162a, 162b Water refill
tank [0326] 164a to 164c Drain [0327] 166 Culture medium material
[0328] 167 Gel particle [0329] 191 Check valve [0330] 194 Part
[0331] 194a, 194b Lip [0332] 195 Slit [0333] 196a, 196b Abutment
surface
* * * * *