U.S. patent application number 16/778507 was filed with the patent office on 2020-05-28 for hydroponic nutrient aeration and flow control device and system.
The applicant listed for this patent is Flow-Rite Controls, Ltd.. Invention is credited to Daniel N. Campau, Mark W. Herrema.
Application Number | 20200163298 16/778507 |
Document ID | / |
Family ID | 69404924 |
Filed Date | 2020-05-28 |
United States Patent
Application |
20200163298 |
Kind Code |
A1 |
Campau; Daniel N. ; et
al. |
May 28, 2020 |
HYDROPONIC NUTRIENT AERATION AND FLOW CONTROL DEVICE AND SYSTEM
Abstract
The specification discloses a hydroponic nutrient aeration and
flow control (NAFC) device and system, which both aerates and
controls the flow of the hydroponic nutrient solution. The NAFC
device has no moving parts. Each NAFC device mixes and aerates the
nutrient from the nutrient reservoir with air and/or nutrient from
one of the grow tanks. Each NAFC device additionally controls the
flow of the aerated nutrient solution to the grow tank and the
nutrient reservoir. The vertical position of the end of the
nutrient return line in each grow tank may be adjusted to adjust
the level of the nutrient solution within the grow tank.
Inventors: |
Campau; Daniel N.; (Ada,
MI) ; Herrema; Mark W.; (Rockford, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Flow-Rite Controls, Ltd. |
Byron Center |
MI |
US |
|
|
Family ID: |
69404924 |
Appl. No.: |
16/778507 |
Filed: |
January 31, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16057116 |
Aug 7, 2018 |
10588276 |
|
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16778507 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A01G 31/02 20130101;
A01G 27/005 20130101; A01G 2031/006 20130101; Y02P 60/21
20151101 |
International
Class: |
A01G 31/02 20060101
A01G031/02 |
Claims
1. A hydroponic nutrient circulation system comprising: a nutrient
reservoir; a plurality of grow tanks; a nutrient supply system for
supplying nutrient from the nutrient reservoir to the grow tanks,
the nutrient supply system including a nutrient supply line
extending into each grow tank; a nutrient return system for
returning nutrient from the grow tanks to the nutrient reservoir,
the nutrient return system including a nutrient return line
extending into each grow tank; an air supply line extending into
each grow tank; and a plurality of aeration devices, each aeration
device within one of the grow tanks, each aerator device including:
a nutrient supply intake connected to the associated nutrient
supply line; an air intake connected to the associated air supply
line; a nozzle in fluid communication with the nutrient supply
intake; a mixing chamber in fluid communication with the nozzle and
with the air intake; and an outlet in fluid communication with the
mixing chamber.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to hydroponics, and more
particularly to hydroponic nutrient circulation systems.
[0002] Hydroponics is the method of growing plants without soil,
using a solution of water and dissolved mineral and/or organic
nutrients. Only the roots are immersed in the nutrient solution,
and sometimes only the tips of the roots are immersed. Because soil
nutrients are not available to the plants, it is critical that all
of the necessary nutrients be added and maintained in the correct
ratios in the nutrient solution. Hydroponic nutrient solutions must
be monitored to ensure that nutrient concentration, oxygen
concentration, pH, and temperature are within desired ranges.
[0003] Hydroponic systems are widely used by hobbyists and
commercial growers. Growers employ a number of techniques to
provide access to nutrients and to maintain the proper nutrient
mixture for the plants.
[0004] Hobbyists with limited production needs may use static
systems in which the plants are supported above a tank of nutrient
solution with only the roots extending into the solution. In these
systems, to assure the roots are continuously immersed, water must
be added to replace the water loss to transpiration and
evaporation. The plants could die if the roots are out of the
solution for only a few hours. Nutrient mixture ratios, pH, and
temperature in each grow tank must be monitored and adjusted as
nutrients are consumed by the plants and as nutrient concentration
changes due to water level changes. Additionally, the plant roots
must have access to oxygen. It is common practice to bubble air
through the nutrient solution so that the solution absorbs
sufficient oxygen to meet plant needs. Air pumps and air stones,
the same as those used in aquariums, are used for this purpose.
[0005] It is common for commercial growers and hobbyists, looking
for more efficient ways to grow larger crops, to use centralized
reservoirs of nutrient solution delivered to multiple grow tanks
using pumps. These types of systems are referred to as
"recirculation systems." They are more practical than static
systems for growing large crops because nutrient solutions can be
monitored and maintained in a single location rather than in each
grow tank.
[0006] In one type of recirculation system, the solution from each
growing tank is returned to the reservoir through gravity return
pipelines. Automatic keep-full valves maintain reservoir level by
adding water to the reservoir as the level drops. Proper nutrient
mixture, pH, and temperature can be maintained for all of the grow
tanks in the network by monitoring and adjusting the reservoir
nutrient solution. The grow tanks still require aeration, which
typically is provided by a large air pump feeding a distribution
manifold so that air may be delivered to each grow tank. These
systems require the grow tanks to be located above the level of the
reservoir so that the gravity return lines can be used.
[0007] In another type of recirculation system, the multiple grow
tanks and the reservoir all are at the same level. The grow pots
are all connected to a common drain line so that they all have the
same liquid level as in the nutrient reservoir. A pump in the
reservoir delivers nutrient solution to each grow pot to provide a
continuous supply of fresh nutrient. Air is supplied by way of an
air pump with air stones in each grow tank. Drainpipe size is
generally large to assure that a common level is maintained in all
of the grow tanks and to assure that aggressive roots do not plug
the drain ports in the grow tanks.
[0008] Systems that use multiple grow tanks connected at the bottom
to a common reservoir at the same level as the grow tanks must all
operate at the same liquid level as the reservoir and each other.
This is not ideal if it is desired to adjust the level of an
individual grow tank to accommodate different plants and root
growth issues, or to use tiered benches to locate grow tanks at
different elevations. The hydroponic method known as Deep Water
Culture is often used in these systems. Plants sit above the
nutrient solution with just some of the roots immersed in the
solution. Grow tanks may have one or more plants. These systems are
not suitable if roots require different nutrient levels or grow
tanks are at different elevations.
[0009] Certain aspects of recirculation systems are less than
ideal. The drain piping system must connect the reservoir directly
with each grow tank. This requires leak-tight joints for grow tank
gravity drain ports to connect with the drain line. Particularly in
systems where grow tanks are elevated relative to the reservoir,
this can be a complex, three-dimensional network of pipes and
joints, thereby adding installation expense and making
modifications problematic. Reconfiguring pipelines requires a
shutdown of the operation, potentially leaving roots exposed to
air. Reconfiguring pipelines also can take significant time, which
adds to the risk of plant damage.
[0010] Aeration also presents problems. Aeration requires air pumps
and lines, which adds cost. Air lines must be routed to all grow
tanks adding to the network cost and complexity.
[0011] There are other problems related to the specific type of
grow tank. The grow tanks that employ the hydroponic system known
as Net Film Technique (NFT) use a thin film of liquid nutrient
flowing from one end to the other in the bottom of a trough-type
tank. This type of grow tank is widely used, for example, in
commercial vegetable and herb operations. Many plants can grow
side-by-side along the length of the trough. The plants sit in
holes in the cover of the trough with the tips of their roots
wetted by the thin layer of flowing nutrient. There are two basic
problems with such tanks. First, gravity drains in these tanks may
allow all nutrient solution to drain out quickly in the event of a
power interruption or pump failure. This can result in the loss of
an entire crop. Second, because these tanks are often rather long,
the flow of nutrient can get restricted by heavy root growth. If
plants are not monitored closely, the problem may not be found
until significant damage has occurred.
SUMMARY OF THE INVENTION
[0012] The present invention provides a hydroponic nutrient
aeration and flow control (NAFC) device and system, which both
aerates and controls the flow of the nutrient solution.
[0013] The NAFC device has no moving parts. The NAFC device
includes a nutrient supply intake, a grow tank return intake, a
nozzle communicating with the nutrient supply intake, a mixing
chamber in fluid communication with both the nozzle and the grow
tank return intake, an outlet port in fluid communication with the
mixing chamber and aligned with the nozzle, and a grow tank supply
outlet in fluid communication with the outlet port. Nutrient from
the nutrient reservoir flows into the nutrient supply intake,
through the nozzle, and into the mixing chamber. Nutrient and/or
air from the grow tank drain line is drawn through the grow tank
return intake and into the mixing chamber. The two nutrient flows
and/or the air are admixed within the mixing chamber, and a portion
of the admixture is directed into the outlet port for delivery to
the grow tank through the grow tank supply outlet.
[0014] The NAFC system includes an NAFC device within each nutrient
supply line to each grow tank. More specifically, the system
includes a nutrient reservoir, a plurality of grow tanks, a
nutrient supply system for supplying nutrient from the reservoir to
the grow tanks, a nutrient return system for returning nutrient
from the grow tanks to the nutrient reservoir, and a plurality of
NAFC devices--with each NAFC device within one of the nutrient
supply lines to one of the grow tanks.
[0015] In an alternative embodiment, the NAFC device may be used as
a hydroponic nutrient aerator (i.e. without a flow control
function).
[0016] The present invention provides significant improvement in
hydroponic system efficiency. The nutrient solution can be mixed,
aerated, and circulated to multiple grow tanks from a nutrient
reservoir; and the nutrient level in each grow tank may be
controlled or adjusted independently of the other grow tanks. The
present invention also eliminates the need for common drain lines,
improving safety and plumbing flexibility, and reducing cost. The
present invention also eliminates the need for holes and leak-tight
connections in the grow tanks for nutrient circulation. Further,
the present invention eliminates the need for air pumps, reducing
system component and installation costs.
[0017] These and other advantages and features of the invention
will be more fully understood and appreciated by reference to the
description of the current embodiment and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a perspective view of a Type I hydroponic nutrient
circulation system embodying the present invention.
[0019] FIG. 2 is a perspective view of a Type II hydroponic
nutrient circulation system embodying the present invention.
[0020] FIG. 3 is a perspective view of a pump and a manifold used
in the Type I system.
[0021] FIG. 4 is an elevational view of the nutrient aeration and
flow control (NAFC) device embodying the present invention.
[0022] FIG. 5 is an exploded sectional view of the NAFC device.
[0023] FIG. 6 is a sectional view of the NAFC device in a first
mode of operation.
[0024] FIG. 7 is a sectional view of the NAFC device in a second
mode of operation.
[0025] FIG. 8 is a sectional view of the aerator portion of the
NAFC device and additionally including a check valve.
[0026] FIG. 9 is a perspective view of the nutrient supply line and
the nutrient return line for a grow tank.
[0027] FIG. 10 is a perspective view similar to FIG. 9 but with a
different filter on the return line.
[0028] FIG. 11 is a perspective exploded view of the area within
the circle XI in FIG. 9.
[0029] FIG. 12 is an elevational view of an alternative embodiment
of the NAFC device.
[0030] FIG. 13 is a sectional view of the alternative embodiment of
the NAFC device.
[0031] FIG. 14 is a perspective view of the alternative embodiment
of the NAFC device connected to both nutrient supply and nutrient
drainage lines.
[0032] FIG. 15 is a perspective view of a grow tank aerator
assembly embodying the present invention.
[0033] FIG. 16 is a schematic illustration of the nutrient flow
within the aerator 22.
[0034] FIG. 17 is a graph illustrating the relationship between
nutrient flow, airflow, and nutrient pressure.
[0035] FIG. 18 is a perspective view of a saddle connection
assembly including the second alternative embodiment of the NAFC
device.
DESCRIPTION OF THE CURRENT EMBODIMENTS
[0036] Before the embodiments of the invention are explained, it is
to be understood that the invention is not limited to the details
of operation or to the details of construction; and the arrangement
of the components set forth in the following description or
illustrated in the drawings. The invention may be implemented in
various other embodiments and may be practiced or carried out in
alternative ways not expressly disclosed herein.
[0037] In addition, it is to be understood that the phraseology and
terminology used herein are for the purpose of description and
should not be regarded as limiting. The use of "including" and
"comprising" and variations thereof encompasses the items listed
thereafter and equivalents thereof as well as additional items and
equivalents thereof. Further, enumeration may be used in the
description of various embodiments. Unless otherwise expressly
stated, the use of enumeration should not be construed as limiting
the invention to any specific order or number of components. Nor
should the use of enumeration be construed as excluding from the
scope of the invention any additional steps or components that
might be combined with or into the enumerated steps or components.
Any reference to claim elements as "at least one of X, Y and Z" is
meant to include any one or more of X, Y or Z individually, and any
combination of any one or more of X, Y and Z, for example, X, Y, Z;
X, Y; X, Z; and Y, Z.
[0038] Directional terms, such as "vertical," "horizontal," "top,"
"bottom," "upper," "lower," "inner," "inwardly," "outer" and
"outwardly," are used to assist in describing the invention based
on the orientation of the embodiments shown in the illustrations.
The use of directional terms should not be interpreted to limit the
invention to any specific orientation(s).
[0039] Embodiments of the hydroponic nutrient aerator and flow
control (NAFC) devices are illustrated in the drawings and
designated 10 and 310. Before the NAFC devices are described in
detail, it is noted the NAFC devices may be used in two types of
hydroponic installations. A "Type I" installation includes grow
tanks arrayed in proximity to the nutrient reservoir. In this type
of system, the NAFC devices 10 are mounted to a manifold connected
to a reservoir pump. A "Type II" installation includes a nutrient
reservoir remote from the grow tanks. In this type of system, the
NAFC devices 310 are distributed throughout the system, with one
NAFC device located near each grow tank.
I. Type I Hydroponic System
[0040] A Type I system is illustrated in FIG. 1 and generally
designated 100. The system 100 includes a nutrient reservoir 102
and a plurality of grow tanks 104. Although six grow tanks 104 are
depicted, the system 100 may include a greater or lesser number of
grow tanks. The system 100 further includes a submersible pump 106
and a manifold 108, shown in greater detail in FIG. 3. The pump 106
and the manifold 108 are submersed in the nutrient reservoir 102.
An NAFC device 10 is mounted to each outlet of the manifold
108.
[0041] The grow tanks 104 may be different in size and number of
plants, may sit at different elevations, and may operate at
different liquid levels. The grow tanks 104 may individually employ
different hydroponic techniques such as Deep Water Culture or Net
Film Technique, as well as any other technique where it is desired
to maintain a volume of nutrient solution matching the condition of
the nutrient reservoir. The grow tanks 104 are not connected to
each other by way of the common drain line. For simplicity, bucket
covers, net pots, and/or other accessories are not shown in
conjunction with the grow tanks 104, although the use of such
component and accessories would be conventional as known to those
skilled in the art.
II. TYPE I NUTRIENT AERATOR AND FLOW CONTROL (NAFC) DEVICE
[0042] The NAFC device 10 will be described in conjunction with the
Type I System 100. Each NAFC device 10 is part of an NAFC assembly
12, which additionally includes a supply hose or line 14 and a
return hose or line 16.
[0043] The NAFC assembly 12 provides independent circulation,
aeration, and level control to the grow tank 104 to which the NAFC
assembly is connected. The NAFC assembly 12 delivers fresh nutrient
and aeration through a supply hose 14 (see also FIG. 9) passing
through a hole in the grow tank cover (not shown) to the bottom of
the grow tank 104. As the level of nutrient in the grow tank 104
rises, the NAFC assembly 12 withdraws liquid from the surface of
the nutrient and returns the withdrawn nutrient to the reservoir
102 through a return hose 16, which also is installed in a hole in
the grow tank cover. The level of the nutrient is maintained within
the grow tank 104 at the lower end 18 of the return hose 16. The
level of the nutrient can be easily adjusted by moving the lower
end 18 of the return hose 14 to the desired level.
[0044] Because the supply hose 14 and the return hose 16 extend
over the top of the grow tank 104 and are secured in position by a
clip 20, which in turn is removably securable to the rim of the
grow tank, no holes are required in the grow tank. This arrangement
assures there are no leaks, and that grow tanks 104 can be
repositioned as needed without downtime or plumbing expense. The
incoming nutrient introduced into the bottom of the grow tank 104
lifts stale nutrient, so the stale nutrient can be drawn off and
returned to the nutrient reservoir 102. In this way, the nutrient
within each grow tank 104 is circulated and maintained in the same
condition as the nutrient in the nutrient reservoir 102.
[0045] Further, the NAFC assembly 10 has an inherent aerating
characteristic, which aerates the nutrient in the nutrient
reservoir 102, and which also mixes air and nutrient solution as
the nutrient solution flows to the grow tank 104. This eliminates
the need for a separate air pump.
[0046] The NAFC device 10 is illustrated in FIGS. 4-7. The NAFC
device 10 is a multiple-function, fluidic device with no moving
parts. The NAFC device 10 includes an aerator 22 and a receiver 24.
The receiver 24 is closely received and secured within the aerator
22. The aerator 22 includes a nutrient inlet 26 and an air inlet 28
for receiving nutrient and air respectively. The aerator 22 further
includes a nozzle 30 and a mixing chamber 38. The nozzle 24
includes a receiver port 32 and an outlet 34. The receiver port 32
is aligned with the nozzle 30.
[0047] As illustrated in FIGS. 6-7, the nutrient inlet 26 is
connected to the manifold 108; the grow tank return hose 16 is
connected to the air inlet 28; and the grow tank supply hose 14 is
connected to the output 34.
[0048] As illustrated in FIG. 6, under the pump pressure at the
inlet 26, a high velocity jet of nutrient solution exits the nozzle
30 into the mixing chamber 38. In the first mode of operation, in
which the end 18 of the grow tank return hose 16 is above the
liquid level in the grow tank 104, air is aspirated into the region
surrounding the nutrient jet in the mixing chamber 38. This enables
the nutrient jet to remain as a coherent jet that travels in a
straight path and impinges on the receiver port 32. Both the liquid
jet and some air enter the receiver port 32. This mix of fluids is
conveyed to the grow tank 104 by way of the grow tank supply hose
14. During the travel to the grow tank 104, the air and the liquid
mix; and oxygen is absorbed into the nutrient solution. Some of the
air aspirated into the nutrient jet bypasses the receiver 32 and
flows into the bypass chamber 41, through the bypass outlet 43, and
into the reservoir 102. In this way, the NAFC devices 10 aerate the
nutrient within the reservoir 102 as well as in the grow tanks
104.
[0049] FIG. 7 illustrates the operation of the NAFC device 10 in a
second mode when the nutrient level in the grow tank 104 rises
above the end 18 of the grow tank return hose 16 within the grow
tank 104. The nutrient liquid is then aspirated and drawn back
through the grow tank return hose 16 and into the NAFC device 10
where it mixes with the nutrient jet in mixing chamber 38. This
causes the nutrient jet to spread and contact the curved wall 40
that surrounds the nutrient jet. The nutrient jet is deflected by
way of Coanda effect or wall attachment effect, and is diverted
away from the receiver port 32. Flow to the grow tank is diminished
or even stopped completely, so that the flow of liquid in the grow
tank return hose 16 causes the grow tank level to drop back to the
end 18 of the hose at which point air is again aspirated and
another cycle of filling is initiated.
[0050] The NAFC device 10 cycles between the mode illustrated in
FIG. 6 and the mode illustrated in FIG. 7 continue as long as the
pump operates. This maintains the level in the grow tank at the end
18 of the grow tank return hose 16 and also circulates aerated
nutrient. Complete turnover time for a given volume of grow tank
nutrient can be controlled by the selection of the NAFC device
nozzle diameter and the pump pressure. For example, an NAFC device
10 with a nozzle diameter of 0.082 inches and a pump pressure of 6
psi will cycle the nutrient solution in a five-gallon grow tank
twice in one hour. Pumps may be run continuously or on a timer.
[0051] The aeration of the nutrient stream within the NAFC device
10 is schematically illustrated in FIG. 16. Nutrient N enters the
device through the intake port 26 and passes through the nozzle 30
to create the jet. The jet mixes with air received through the
intake port 28 and the aerated nutrient N' results.
[0052] FIG. 17 is a graph illustrating the nutrient flow and the
airflow through the NAFC device 10 at various nutrient head
pressures. The nutrient flow exceeds the airflow below a nutrient
head pressure of approximately 10 Ft. And the nutrient flow is less
than the airflow above that nutrient head pressure.
[0053] Because the end of the grow tank supply hoses are submerged,
an anti-siphon means is provided to introduce air into the hoses
when the pump is off. Anti-siphon means may be a small hole 42 in
the side of the hose above the nutrient level as illustrated in
FIG. 11.
[0054] Further, because the grow tank return hose 16 can
potentially be submerged at its end 18 when the pump turns off, a
check valve 44 may be placed in the intake port 28 to prevent the
contents of the nutrient tank from siphoning into the grow tank if
the grow tank nutrient level is below the nutrient reservoir level.
If the grow tank nutrient level is above the nutrient reservoir
level when the pump shuts off, the grow tank nutrient level will
drop to the set point which is the vertical position of the end 18
of the hose 16 in the grow tank. The check valve 44 is preferably a
duckbill type, but other check valves could be used. A low opening
differential pressure is preferred so the aspiration of nutrient
from the grow tank can occur at the fastest rate.
[0055] FIGS. 9 and 10 illustrate the mounting of the hoses 14 and
16 on the grow tank 104. A bracket 20 attaches to the rim 46 of the
grow tank 104 and directs the hoses downwardly into the grow tank.
The supply hose 14 extends to a low level (as described above), and
the end 19 preferably is positioned near the horizontal center of
the grow tank 104, so that nutrient and air are introduced near the
middle of the lower portion of the grow tank.
[0056] As illustrated in FIG. 9, the end 18 of the return hose 16
includes a filter 46 that prevents roots from entering the hose 16
and potentially blocking the hose. The filter 46 preferably is a
porous plastic material. A porous plastic material is preferred
over meshes or screens because roots can penetrate the openings in
those types of filters. The return hose 16 may be slid within the
bracket 20 so that the end 18 and the filter 46 may be placed at
the desired nutrient solution level for the grow tank 104. The
desired nutrient level may differ between plant pot sizes and may
also change as the roots develop. In some cases, as the roots grow,
the level will be set lower so that the root tips remain submerged
while the root mass may be exposed to air to improve oxygen
absorption. Preferably, the return hose 16 is marked with a
graduated scale indicating the depth of the nutrient liquid level.
The system holds the liquid level accurately at the location of the
end 18 of the return hose 16.
[0057] FIG. 10 illustrates a tubular filter or equalizer tube 46a,
which may be used in place of the filter 46 illustrated in FIG. 9.
The return hose 16 is located inside of the tubular filter 46a with
its lower end 18 at the level set point. The inside diameter of the
tubular filter 46a is larger than the outer diameter of the return
hose 16. The porosity of the tubular filter 46a enables the liquid
level inside the tubular filter to equalize with the grow tank
level. The tubular filter 46a offers increased filter area for
longer filter life.
III. TYPE II HYDROPONIC SYSTEM
[0058] A Type II System is illustrated in FIG. 2 and generally
designated 200. The system 200 includes a nutrient reservoir 202
and a plurality of grow tanks 204. The nutrient solution within the
nutrient reservoir 202 is distributed to the grow tanks 204 by way
of a network of pressure pipes 210 and return pipes 212. The
pressure and return pipes 210, 212 can be fitted with quick
disconnects at each grow tank location so that each NAFC device 10
may be snapped into or removed from the pipes without interrupting
the system operation. The reservoir 202 and the grow tanks 204 may
be similar to, or different from, the reservoir 102 and the grow
tanks 104 respectively.
IV. TYPE II NUTRIENT AERATOR AND FLOW CONTROL (NAFC) DEVICE
[0059] FIGS. 12 and 13 illustrate the NAFC device 310 for a Type II
hydroponic system. The NAFC device 310 includes an aerator 322 and
a receiver 324.
[0060] The aerator 322 is highly similar structurally and
functionally to the aerator 22 previously described. The elements
in the aerator 322 that correspond to elements in the aerator 22
are identified by the corresponding number preceded by the digit
"3". Accordingly, the inlet port 326 corresponds to the inlet port
26, and so forth. The primary difference between the aerator 322
and the aerator 22 is that the inlet port 326 is threaded to
receive a mating threaded component.
[0061] The receiver 324 is highly similar functionally to the
aerator 22 previously described. The elements in the receiver 324
that correspond to elements in the receiver 24 are identified by
the corresponding number preceded by the digit "3". Accordingly,
the receiver port 332 corresponds to the receiver port 32, and so
forth. Two differences between the receiver 324 and the receiver 24
are that (a) the grow tank supply line port 334 extends
transversely from the NAFC device 310 and (b) the outlet 335
includes an external fitting 337.
[0062] FIG. 14 illustrates the incorporation of the NAFC device 310
into the Type II system 200. The pressure line 210 is fitted with a
tee 206 at each growing tank 204 along with a quick coupling 208
having a shut-off valve (not visible). Similarly, the drain line
212 is fitted with a tee 214 along with a quick coupling having a
shut-off valve (not visible). All of these components are fluidly
and securely interconnected using techniques well known to those
skilled in the art.
[0063] The valves enable the NAFC unit 310 to be installed and
removed without shutting off the pump. This enables modifications
and service to be performed on individual growing stations without
interrupting system operation. The drain line is always filled with
nutrient solution at the reservoir head pressure. The check valves
prevent the nutrient from leaking out when the NAFC device 310 is
not installed.
[0064] Preferably, the NAFC device 310 is fitted with male
quick-connect fittings. When installing the NAFC into a pressurized
line, the NAFC grow tank connections are made first. Then the NAFC
outlet is connected to the drain line. Then the NAFC inlet fitting
is inserted into the quick coupler, which opens the shut-off valve,
and operation begins. When removing the NAFC device 310, the quick
coupling is first disconnected from the pressurized line, and then
the NAFC device is disconnected from the drain coupling and the
grow tank tubes.
[0065] FIG. 18 illustrates an alternative embodiment to the
arrangement illustrated in FIG. 14 for connecting the NAFC device
310 in a Type II system 200. The FIG. 18 design incorporates pipe
saddles 510 that may be attached to the nutrient supply line 210
and the nutrient drain line 212. The saddles 510 include
sprinkler-system, snap-on, self-tapping tees 512 and 514 to connect
the NAFC device 310 to the lines 210 and 212 respectively. The tees
512 and 514 simplify and reduce installation labor because the
self-tapping tool is incorporated into the saddle 510. The saddles
510 can be added to an existing pipe run without draining the
pipes. One suitable saddle is that made and sold by King
Innovations for use in underground sprinkler systems.
V. HIGH EFFICIENCY AERATOR
[0066] Many hydroponic growers would like to improve the aeration
in their recirculation systems. Air pumps, air stones, and
associated airlines require maintenance and may not always provide
sufficient oxygen to the plant roots. Accordingly, there is a need
for improved aeration in many existing hydroponic recirculation
systems.
[0067] There are alternatives to air pumps for aeration, but these
alternatives create problems when used in multiple tank
recirculation systems. Pumps fitted with a venturi aspirate air and
mix it with nutrient. These pumps are too large and too expensive
to connect to each grow tank to circulate individual nutrient
solution. If a large, single-venturi pump is used to augment
nutrient aeration and circulation, such a pump may increase the
flow rate beyond the grow tank drain capacity or not provide
sufficient oxygen if flow is limited. There are also aerators used
for marine live wells and bait wells that are designed to operate
with 500 GPH to 750 GPH or more. These marine aerators are
impractical to circulate individual grow tank nutrient with their
own pump, and would be problematic if mounted to each grow tank and
supplied by a system pump. At high enough flow rate to provide
enough air, the flow into the grow tanks would exceed drain
capacity, leading to uneven nutrient levels and potentially even
overflows.
[0068] The NAFC has a mode of configuration and operation ideal for
this situation. When the receiver 24 is not installed in the
aerator 22, the NAFC device may operate as a high-efficiency,
low-liquid-flow-rate aerator. Configured in this mode, and
designated NAFC-A, an aerator 22 may be mounted to each grow tank
and supplied by a central recirculation pump. The individual
aerators 22 have a relatively low flow rate, so grow tank capacity
will not be exceeded. However, the aerator 22 generates a high
velocity liquid jet, which creates a strong aspiration of air into
the jet. The strength of the aspiration effect is reflected by
comparing the strength of the vacuum head created by the NAFC-A
with other aerators at their normal operating flow rate. The
aerator 22 operating at 10 Ft. of head develops a liquid flow rate
of 0.65 GPM or 39 GPH. This is a manageable flow rate for a typical
6-gallon grow tank drain system. This aerator produces a turnover
rate of once every 6 minutes for a tank filled with 4 gallons of
nutrient.
[0069] FIG. 15 illustrates one embodiment of a grow tank aerator
assembly 400 incorporating the NAFC-A aerator 422. The assembly 400
includes an aerator 422, an air supply pipe 402, a nutrient inlet
port 426, a discharge tube 404, and a U 406. Nutrient is received
through intake port 426, and the nutrient flows through the aerator
422 to be aerated as described above. The aerated nutrient solution
is outputted into the tube 404 for discharge through the U 406 into
the grow tank (not shown in FIG. 15). The U 406 enables the aerator
assembly 400 to be mounted on the rim of a grow tank.
VI. CONCLUSION
[0070] The NAFC devices provide unique features to improve the
performance of hydroponic nutrient circulation systems. The devices
aerate the nutrient solution without the need for air pumps, air
stones, and air tube plumbing. The devices circulate aerated
nutrient solution without gravity drains or a common drain line
connecting grow tanks and the nutrient reservoir. The devices
provide individual grow tanks with adjustable level control without
the need for mechanical or electrical valves. The devices can empty
grow tanks without requiring drain holes in the grow tanks. The
devices enable grow tanks to be mounted at individual elevations.
The devices enable different size grow tanks to be serviced from
the same nutrient reservoir. The devices, when appropriately sized,
provide rapid cycling (i.e. turnover) of grow tank nutrient
solution. The devices may work with continuous or timed pump
operation. The devices may be used with the most popular types of
existing hydroponic systems. The devices enable an individual grow
tank in a network to be serviced (i.e. moved, emptied, cleaned,
replanted, etc.) without interrupting operation of the other tanks
in the network.
[0071] The aerator version (i.e. the NAFC-A device) delivers high
aeration to individual grow tanks without exceeding the existing
drain capacity of the systems.
[0072] The above descriptions are those of current embodiments of
the invention. Various alterations and changes can be made without
departing from the spirit and broader aspects of the invention as
defined in the appended claims, which are to be interpreted in
accordance with the principles of patent law including the doctrine
of equivalents.
[0073] This disclosure is illustrative and should not be
interpreted as an exhaustive description of all embodiments of the
invention or to limit the scope of the claims to the specific
elements illustrated or described in connection with these
embodiments. For example, and without limitation, any individual
element(s) of the described invention may be replaced by
alternative elements that provide substantially similar
functionality or otherwise provide adequate operation. This
includes, for example, presently known alternative elements, such
as those that might be currently known to one skilled in the art,
and alternative elements that may be developed in the future, such
as those that one skilled in the art might, upon development,
recognize as alternatives.
[0074] Further, the disclosed embodiments include a plurality of
features that are described in concert and that might cooperatively
provide a collection of benefits. The present invention is not
limited to only those embodiments that include all of these
features or that provide all of the stated benefits, except to the
extent otherwise expressly set forth in the issued claims. Any
reference to claim elements in the singular, for example, using the
articles "a," "an," "the" or "said," is not to be construed as
limiting the element to the singular.
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