U.S. patent application number 13/360078 was filed with the patent office on 2012-11-29 for electrically insulated air-conducting water heater.
Invention is credited to Yen-Chieh HUANG.
Application Number | 20120297530 13/360078 |
Document ID | / |
Family ID | 47218189 |
Filed Date | 2012-11-29 |
United States Patent
Application |
20120297530 |
Kind Code |
A1 |
HUANG; Yen-Chieh |
November 29, 2012 |
ELECTRICALLY INSULATED AIR-CONDUCTING WATER HEATER
Abstract
Electric shock to a user has been a major concern for a
conventional electric water heater installed in or near a bathroom.
An electrically insulated air-conducting water heater utilizes
electrically insulating hot air to indirectly heat water to avoid
electric hazard to a user of an electric water heater. The present
invention comprises an air pump unit, a heating and temperature
control unit, and an air venting unit having a plurality of tiny
air nozzles immersed in a water pool. Ambient air is collected by
the air pump unit, heated in the heating and temperature control
unit, and injected into a water pool through the air venting unit
as a form of zillions of small hot bubbles to heat the water. Apart
from serving as an electrically safe water heater, the present
invention also functions as a hot-bubble sauna machine, bathroom
body dryer, and air conditioner.
Inventors: |
HUANG; Yen-Chieh; (Hsinchu
City, TW) |
Family ID: |
47218189 |
Appl. No.: |
13/360078 |
Filed: |
January 27, 2012 |
Current U.S.
Class: |
4/493 |
Current CPC
Class: |
A45D 20/16 20130101;
A61H 33/025 20130101; A61H 33/028 20130101; A61H 33/063 20130101;
E04H 4/129 20130101 |
Class at
Publication: |
4/493 |
International
Class: |
E04H 4/14 20060101
E04H004/14 |
Foreign Application Data
Date |
Code |
Application Number |
May 27, 2011 |
TW |
100118661 |
Claims
1. An electrically insulated air-conducting water heater, which
uses a plurality of hot air bubbles to heat water in a water pool,
comprising an air pump unit including an air inlet to collect
ambient air and then press forward the ambient air;. a heating and
temperature control unit connecting with the air pump unit to heat
the ambient air pressed down by the air pump unit to form hot air;
and an air venting unit including a plurality of tiny air nozzles,
immersed in the water pool, connecting with the heating and
temperature control unit to receive the hot air via an air conduit,
and releasing the hot air via the tiny air nozzles.
2. The electrically insulated air-conducting water heater according
to claim 1, wherein the air venting unit includes an air-storage
volume and a thermal conductive structure, and wherein the thermal
conductive structure includes two opposite surfaces, one in contact
with water and the other in contact with hot air.
3. The electrically insulated air-conducting water heater according
to claim 2, wherein the thermal conductive structure is arranged on
one side of the air venting unit, facing down the bottom of a water
pool.
4. The electrically insulated air-conducting water heater according
to claim 2, wherein the air venting unit includes at least one
sucking disk on the surface facing the bottom of the water
pool.
5. The electrically insulated air-conducting water heater according
to claim 2, wherein an air-impermeable plastic film partitions the
air-storage volume into an upper heat transfer compartment and a
lower heat transfer compartment, and wherein one side of the lower
heat transfer compartment joins with the thermal conductive
structure.
6. The electrically insulated air-conducting water heater according
to claim 1, wherein the air venting unit includes a plurality of
protrusions arranged on the upper surface thereof.
7. The electrically insulated air-conducting water heater according
to claim 2, wherein the thermal conductive structure is made of a
material selected from a group consisting of metal, plastic, and
rubber.
8. The electrically insulated air-conducting water heater according
to claim 1, wherein the tiny air nozzles have aperture diameters
between 1 and 1000 .mu.m.
9. The electrically insulated air-conducting water heater according
to claim 1, wherein the air inlet includes a filter arranged
inside.
10. The electrically insulated air-conducting water heater
according to claim 1, wherein the air conduit further includes at
least one air outlet directly blowing the hot air to the space
outside the water pool.
11. The electrically insulated air-conducting water heater
according to claim 10, wherein a plurality of air directing fins
arranged in the air outlet to adjust and control the flow direction
of the hot air.
12. The electrically insulated air-conducting water heater
according to claim 1, wherein the heating and temperature control
unit includes an electric heater to heat the air.
13. The electrically insulated air-conducting water heater
according to claim 1, wherein the heating and temperature control
unit includes a temperature controller for a user to set the
temperature of the air.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a water heater,
particularly to a water heater using electrically insulating air as
a heat conducting medium to increase water temperature.
BACKGROUND OF THE INVENTION
[0002] In general, there are two types of water heaters, one
burning natural gas and the other consuming electricity to raise
the temperature of water. The latter is often adopted as a
replacement for the former to avoid the danger of carbon-monoxide
poisoning. However, a conventional electrical water heater employs
an electric heating element or coil in direct contact with water
through a heat conducting metallic material. In practice, only pure
water is a good insulator. A user of an electric water heater could
be constantly exposed to electric hazard when, for instance, taking
a bath. The present invention overcomes this difficulty by adopting
air, a much better electrically insulating medium, to conduct heat
from an electric heating element to water. The present invention is
not just an electrically safe water heater but also a hot-air sauna
machine when injecting hot air into a bath tub. In a cold weather,
the present invention can at the same time serve as an air
conditioner or a comfortable body dryer in a bathroom.
SUMMARY OF THE INVENTION
[0003] The primary objective of the present invention is to
overcome the problem that the conventional electric water heater
may cause electric shock to a user.
[0004] To achieve the abovementioned objective, the present
invention discloses an electrically insulated air-conducting water
heater, which applies a plurality of small hot air bubbles to heat
water in a water pool. The present invention comprises an air pump
unit, a heating and temperature control unit, and an air venting
unit having a plurality of tiny air nozzles.
[0005] The air pump unit is an air pump that takes in ambient air
and transports it into the heating and temperature control unit.
The heating and temperature control unit raises the temperature of
the air to a suitable level and generates hot air. The hot air
propagates down an air conduit to an air venting unit placed in a
water pool. Hot air is released into water through the air venting
unit to heat the water.
[0006] The air venting unit has a plurality of tiny air nozzles,
through which hot air is injected into water in the form of a great
number of micro hot air bubbles. Since a micro air bubble has a
smaller buoyant force compared with that of a large air bubble, a
micro-bubble can be kept in water for a longer time to heat the
water. Furthermore, the overall heating area of a great number of
micro-bubbles can be significantly larger than that of a single
large air bubble of the same volume Therefore, the heat stored in
the air can be efficiently conducted to water. The following theory
provides a concrete proof to the concept.
[0007] It is well known that heat transfer efficiency between two
objects is proportional to the surface contact area between them.
The following compares the surface area of a large air bubble with
that of a number of small bubbles derived from the same air volume
of the large bubble. Suppose that a large hot air bubble in water
has a radius of r.sub.b. Thus, the large hot air bubble has a
surface area S.sub.b and a volume V.sub.b, expressed by Equations
(1,2), respectively:
S.sub.b=4.pi.r.sub.b.sup.2 (1)
V.sub.b=4.pi.r.sub.b.sup.3/3 (2)
Suppose that the large hot air bubble is divided into N small air
bubbles of the same size, and assume that each small air bubble has
a radius of r.sub.s. Thus, the total surface area of small air
bubbles in contact with water S.sub.s is given by Equation (3):
S.sub.s=N4.pi.r.sub.s.sup.2 (3)
The total volume of the small hot bubbles V.sub.s can be expressed
by Equation (4):
V.sub.s=N4.pi.r.sub.s.sup.3/3 (4)
It is straightforward to obtain the ratio of the bubble's surface
areas for the two cases by taking the ratio of Equations (1) and
(3), given by:
S.sub.s/S.sub.b=N(r.sub.s/r.sub.b).sup.2 (5)
For a fair comparison, the air volume is kept constant or
V.sub.b=V.sub.s. From Equations (2, 4), the following relationship
holds for an equal air volume
N4.pi.r.sub.s.sup.3/3=4.pi.r.sub.b.sup.3/3 (6)
or
r.sub.s/r.sub.b=(1/N).sup.1/3 (7)
By substituting Equation (7) into (5), the area ratio
S.sub.s/S.sub.b becomes:
S.sub.s/S.sub.b=N.sup.1/3 (8)
Equation (8) clearly shows that a large amount of small air bubbles
can have a much larger heat-transfer contact area than does a
single large air bubble of the same air volume. Suppose that a
plurality of tiny air nozzles divide a large hot air bubble into
one million small hot air bubbles. According to Equation (8), the
surface area of all the small hot air bubbles is 100
(=(1,000,000).sup.1/3) times greater than that of the large hot air
bubble. Thus, the heating efficiency of those small hot air bubbles
is 100 times that of the single large hot air bubble. Normally, it
is not difficult to fabricate tiny air nozzles on an air venting
unit. For example, laser micro-machining is a convenient technique
to drill micro-air nozzles on materials.
[0008] As mentioned above, a smaller hot bubble has smaller buoyant
force and can stay in water over a longer time. According to the
Archimedean principle, a body immersed in a fluid gets a buoyant
force F.sub.B equal to the weight of the fluid it displaces. In
other words, a bubble experiences a buoyant force equal to the
weight of the water having the same volume as the bubble:
F.sub.B=.rho.Vg (9)
where V is the volume of a bubble, p is the density of a fluid, and
g is the gravitational acceleration. It is evident from Equation
(9) that the buoyant force F.sub.B and thus the upward acceleration
of the bubble in water are proportional to its own volume. In other
words, a smaller hot bubble can stay in water longer than a larger
one. This increased heating time allows the smaller hot air bubbles
to transfer more heat to water.
[0009] Thus, the disclosure of using a large amount of hot
micro-bubbles to heat water is a key technical advancement of the
present invention. The small bubble size not only increases the
heat transfer area between air and water but also increases the
heating time of air to water. This technical advancement
effectively increases the heat transfer efficiency from hot air to
water.
[0010] The air venting unit further comprises an air-storage volume
and a thermal conductive structure. The air venting unit is
immersed in water in a water pool or a bath tub. The thermal
conductive structure is made of heat conducting materials with two
planar sides, one exposed to the air-storage volume and the other
exposed to water in the water pool. The hot air propagates down the
air venting unit through an air conduit. The heat energy stored in
the hot air can be quickly transferred to water via the thermal
conductive structure in contact with the air-storage volume. The
tiny air nozzles of the air venting unit divide the hot air into
small hot bubbles. The residual heat energy stored in the hot air
is carried to the small hot air bubbles and released to water.
[0011] In summary, ambient air is taken into an air pump unit and
heated by the heating and temperature control unit to form hot air.
The hot air is sent into an air venting unit through an air
conduit. When the hot air is transported into an air storage volume
in contact with a thermal conductive structure in the air venting
unit, the hot air quickly transfers part of its heat energy to the
thermal conductive structure to heat up the temperature of the
water in contact with the other side of the thermal conductive
structure. The hot air in the air-storage volume is then released
to water through a plurality of tiny air nozzles, which generate a
large number of air bubbles to continuously transfer heat to water,
massage a user in a bath tub, or warn up the temperature of a cold
bathroom.
[0012] According to the aforementioned concepts, the present
invention employs electrically insulating hot air as a heating
medium for a water heater. Electric energy is first transferred to
heat energy stored in air, which is then transferred to water
through a thermal conductive structure, or a large number of hot
air bubbles in water, or both. This water heating process ensures
electric insulation between the electricity and a user in water.
The high speed air bubbles ejected from the tiny air nozzles in the
air venting unit can at the same time generate ultrasound to
massage or clean a user in the water pool, dry the body of a person
or a pet animal, and warm up a cold bathroom.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a diagram schematically showing the structure of
electrically insulated air-conducting water heater according to the
present invention;
[0014] FIG. 2 is a diagram schematically showing the structure of
an electrically insulated air-conducting water heater according to
a first embodiment of the present invention;
[0015] FIG. 3 is a diagram schematically showing a detailed air
venting unit of an electrically insulated air-conducting water
heater according to the first embodiment of the present invention;
and
[0016] FIG. 4 is a diagram schematically showing the structure of
an electrically insulated air-conducting water heater according to
a second embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] The technical contents of the present invention are
described in details with reference to the drawings above.
[0018] Refer to FIG. 1, a diagram schematically showing the
structure of an electrically insulated air-conducting water heater
according to the present invention. The water heater of the present
invention uses a plurality of small hot bubbles 4 to heat water 3
in a water pool 5, comprising an air pump unit 10, a heating and
temperature control unit 20, and an air venting unit 30. The air
pump unit 10 takes in the ambient air 1 via an air inlet 11, and
then sends the ambient air 1 to the heating and temperature control
unit 20 via an air channel 23. The heating and temperature control
unit 20 heats the ambient air 1 to form hot air 2. The hot air 2 is
sent to the air venting unit 30 via an air conduit 31. A plurality
of tiny air nozzles 32 of the air venting unit 30 divides the hot
air 2 into a plurality of small hot bubbles 4. The small hot
bubbles 4 are released to the water 3 to heat the water 3.
[0019] Refer to FIG. 2 a diagram schematically showing the
structure of an electrically insulated air-conducting water heater
according to a first embodiment of the present invention. The air
pump unit 10 has an air inlet 11 to take in the ambient air 1 and
then pump the ambient air 1 to the heating and temperature control
unit 20. In the first embodiment, a filter 111 is arranged inside
the air inlet 11 to prevent foreign objects from entering the air
pump unit 10. The heating and temperature control unit 20,
following the air pump unit 10 through an air channel 23, heats the
ambient air 1 sent down by the air pump unit 10. The hot air 2
propagates down the air conduit 31 to reach the air venting unit
30. The air venting unit 30 is immersed in the water pool 5 and has
a plurality of tiny air nozzles 32 on the surface enclosing an
air-storage volume 33. The hot air 2 transferred to the air-storage
volume 33 is then divided into a plurality of small hot bubbles 4
by a plurality of tiny air nozzles 32 of the air venting unit 30.
Then, the hot air 2 is released to the water 3 in the form of small
hot bubbles 4. In the first embodiment, the tiny air nozzles 32 are
distributed on a surface of the air venting unit 30. The diameter
of the tiny air nozzles 32 is varied according to the desired
heating rate to water. For example, tiny air nozzles 32 having
smaller diameters can generate smaller hot bubbles 4 and increase
the total number of the bubbles 4 in water. As previously proved,
the small bubble can favorably increase the heat transfer area
between and contact time of the hot air and water. The diameters of
the tiny air nozzles 32 are preferably between 1 and 1000 .mu.m.
Alternatively, the tiny air nozzles 32 can be distributed on
selective sides or certain area of the air venting unit 30. For
example, under certain situation, a user 6 immersed in a bath tub
might want to avoid direct contact with the hot-air nozzles.
[0020] The air venting unit 30 may further comprise a thermal
conductive structure 37 having two opposite surfaces. The thermal
conductive structure 37 is made of partially or fully heat
conducting materials with two surfaces. One surface is exposed to
the air-storage volume 33 to extract heat from the hot air, and the
other is exposed to the water 3 in the water pool 5 to release heat
to the water. In the first embodiment, the thermal conductive
structure 37 is arranged at one side of the air venting unit 30,
facing down the bottom of the water pool 5 to avoid a direct
contact with a user 6. The thermal conductive structure 37 can be a
high thermal-conductivity material such as a metal plate with or
without a honeycomb structure, or simply some plastic or rubber
with good heat conductivity.
[0021] Refer to FIG. 3, a diagram schematically showing a detailed
air venting unit of an electrically insulated air-conducting water
heater according to the first embodiment of the present invention.
In the first embodiment, an air-impermeable plastic or rubber film
36 partitions the air-storage volume 33 into a upper heat transfer
compartment 331 and a lower heat transfer compartment 332. The
lower heat transfer compartment 332 having one side joint with the
thermal conductive structure 37. The hot air 2 propagates down the
air conduit 31, enters the lower heat transfer compartment 332
first, and then enters the upper heat transfer compartment 331. As
a result, the heat energy stored in the hot air 2 is first
transferred to the thermal conductive structure 37 and then
released to water through the tiny air nozzles 32. Specifically,
when passing through the lower heat transfer compartment 332, the
hot air 2 contacts the thermal conductive structure 37. The thermal
conductive structure 37 comprises a sheet or a plurality of thermal
conductive elements 371 and a plurality of air nozzles 372. The air
nozzles 372 are interleaved with or fabricated on the thermal
conductive element 371. When the hot air 2 passes the lower heat
transfer compartment 332, the heat energy stored in the hot air 2
is transferred to the water 3 through the thermal conductive
element 371 and some hot air 2 is released to the water 3 in the
form of small hot bubbles 4 via the air nozzles 372. The thermal
conductive element 371 may be made of a material such as plastic,
rubber, or metal having a good thermal conductivity. The remaining
hot air 2 continues to propagate into the upper heat transfer
compartment 331 and enter the water 3 in the form of small hot
bubbles 4 via the tiny air nozzles 32 on the top surface of the
upper heat transfer compartment 331. The hot bubbles 4 exiting the
tiny air nozzles 32 provide further heating to the water 3. The
user 6 can also enjoy a sauna bath from those bubbles, getting
herself or himself cleaned, massaged, and relaxed. Further, the hot
air 2 going out from the water 3 can be used to warm up a bathroom
in a cold weather. The air-impermeable plastic film 36 separate the
air-storage volume 33 into the upper heat transfer compartment 331
and lower heat transfer compartment 332. Since the heat is first
released to the lower heat transfer compartment 332, this
embodiment of the present invention keeps a high temperature zone
facing the bottom of the water pool but not facing the user 6. To a
user's comfort, a user can certainly adjust the heat transfer rate
by varying the pumping and heating speed from the air pump unit 10
and the heating and temperature control unit 20, respectively.
[0022] The air venting unit 30 may further have at least one
sucking disk 35 on the surface facing the bottom of the water pool
5. In the first embodiment, the air venting unit 30 is fixed to the
bottom of the water pool 5 or commonly a bathtub by a plurality of
sucking disks 35. The sucking disks 35, with some finite height,
can provide a gap space between the thermal conductive structure 37
and the bottom of the water pool 5, in which the water 3 can
contact the thermal conductive structure 37 to absorb the heat
energy from the thermal conductive structure 37. In the first
embodiment, a plurality of protrusions 34 is arranged on the upper
surface of the air venting unit 30. The protrusions 34 on one hand
prevent a user from blocking the air nozzles 32 when lying on the
air venting unit 30, and on the other hand provide some pressure
points to a user when a user lies in the water pool 5 to enjoy
sauna massage.
[0023] Refer to FIG. 4, a diagram schematically showing the
structure of an electrically insulated air-conducting water heater
according to a second embodiment of the present invention. In the
second embodiment, the heating and temperature control unit 20
includes an electric heater 21 and a temperature controller 22. The
electric heater 21 heats the ambient air 1 entering the heating and
temperature control unit 20 to form the hot air 2. The temperature
controller 22 controls the heating intensity of the electric heater
21 according to a user pre-set temperature for the hot air. In the
second embodiment, the air conduit 31 further has at least one air
outlet 311a, 311b and 311c. The hot air 2 is directly blown into
the open space from the air outlets 311a and 311b without going
through the water in the water pool 5. The user 6 may use the hot
air 2 from the air outlets 311a and 311b to dry hairs, hands, or
any other part of the user's body. Therefore, the present invention
also functions as a hair dryer and a hand dryer. In a cold
environment, additional air outlet 311c can be extended from the
air conduit 31 to serve as a warm air source of an air conditioner.
Further, a plurality of air directing fins 312 may be arranged in
the air outlet 311c to adjust and control the flow direction of the
hot air 2. It should be pointed out that the layout of the air
conduits and outlets shown in FIG. 4 is not a unique one but only
to exemplify the concept of the present invention. The present
invention may adopt a different arrangement for the air conduits
and outlets at different locations, angles, and heights to meet the
functional purposes of a hair dryer, hand dryer, body dryer, or air
conditioner. For example, a flexible bellow-type air conduit with
an outlet can be provided to a user for convenience of usage.
Furthermore, a control valve 313 may be used to switch the hot air
2 to blow out from a single air outlet or from multiple air outlets
simultaneously. The functions of the present invention are not
limited to serving a human user but can be extended to serving a
pet animal.
[0024] In conclusion, the electrically insulated air-conducting
water heater of the present invention adopts non-conducting air as
a heat-transfer medium to heat water, so as to avoid potential
electric hazard to a hot-water user. The non-conducting air is
collected by an air pump, heated electrically in the heating and
temperature control unit of the present invention, and injected
into water directly as a form of bubbles to heat water. To
effectively transfer the stored thermal energy in the hot air to
water, injecting micro-bubbles into water from micron-size air
nozzles is disclosed as a major advancement and key embodiment of
the present invention. A second embodiment of the present invention
is to firstly transfer part of the thermal energy of the hot air to
a thermally conductive material in contact with water and secondly
inject the hot air bubbles into water for further water heating. A
user of the present invention can adjust the temperature of the air
through the heating and temperature control unit of the present
invention according to the desired water-heating rate, the desired
bathroom temperature, or personal joy and comfort from a hot-bubble
sauna. The present invention can function simultaneously as an
electrically safe water heater, a hot-bubble sauna machine, a hand
dryer, a hair dryer, a body dryer, and an air conditioner to a
human user or a pet animal.
[0025] The embodiments described above are only to exemplify the
present invention but not to limit the scope of the present
invention. Any equivalent modification or variation according to
the spirit of the present invention is to be also included within
the scope of the present invention. For example, the generation of
the hot air does not require an installation of the air pump unit
in front of the heating and temperature control unit. A system
reversing the sequence of the installation is still well within the
scope of the present invention. Also, the diameters of the air
nozzles are not necessarily uniform for all nozzles. The present
invention can adopt different size nozzles at different locations
on the air venting unit to optimize the heating rate to water and
the comfort to a user.
* * * * *