U.S. patent application number 11/391229 was filed with the patent office on 2006-08-03 for heat exchanger and heat exchange ventilator.
This patent application is currently assigned to MITSUBISHI DENKI KABUSHIKI KAISHA. Invention is credited to Hidemoto Arai, Youichi Sugiyama, Kenzou Takahashi.
Application Number | 20060168813 11/391229 |
Document ID | / |
Family ID | 19163548 |
Filed Date | 2006-08-03 |
United States Patent
Application |
20060168813 |
Kind Code |
A1 |
Arai; Hidemoto ; et
al. |
August 3, 2006 |
Heat exchanger and heat exchange ventilator
Abstract
A heat exchanger for realizing a high degree of humidity
exchange efficiency at a low cost. The heat exchanger in which
partition members respectively separated from each other by a
spacing maintained by one of spacing members facilitate circulation
of two different air flows, with total enthalpy heat exchange
occurring between these two air flows via the partition members.
The partition members comprise an air shielding sheet type material
comprising a hydrophilic fiber and also including a moisture
absorbent, and the air permeability (JIS P 8117) of the partition
members is at least 200 seconds/100 cc.
Inventors: |
Arai; Hidemoto; (Tokyo,
JP) ; Takahashi; Kenzou; (Tokyo, JP) ;
Sugiyama; Youichi; (Tokyo, JP) |
Correspondence
Address: |
BUCHANAN INGERSOLL PC;(INCLUDING BURNS, DOANE, SWECKER & MATHIS)
POST OFFICE BOX 1404
ALEXANDRIA
VA
22313-1404
US
|
Assignee: |
MITSUBISHI DENKI KABUSHIKI
KAISHA
|
Family ID: |
19163548 |
Appl. No.: |
11/391229 |
Filed: |
March 29, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10189556 |
Jul 8, 2002 |
|
|
|
11391229 |
Mar 29, 2006 |
|
|
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Current U.S.
Class: |
29/890.039 ;
29/890.038; 29/890.054 |
Current CPC
Class: |
F24F 2003/1435 20130101;
F28D 21/0015 20130101; F28D 9/0062 20130101; Y10T 29/49364
20150115; Y10T 29/49393 20150115; Y10T 29/49366 20150115; F24F
3/147 20130101 |
Class at
Publication: |
029/890.039 ;
029/890.038; 029/890.054 |
International
Class: |
B21D 53/04 20060101
B21D053/04 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 16, 2001 |
JP |
2001-351213 |
Claims
1. A method of manufacturing a heat exchanger of the type in which
partition members respectively separated from each other by a
spacing maintained by a spacing member to facilitate circulation of
two different air flows, with total enthalpy heat exchange
occurring between said two air flows via said partition members,
wherein the method comprises the steps of: applying a coating
solution comprising a moisture absorbent and no flame retardant to
a first base material for the partition members, the base material
prepared by wet beating to obtain a fine hydrophilic fiber, making
a paper in a warm water using the fine hydrophilic fiber, rolling a
wet paper with a moisture content of 15 to 25% and subsequently
calendaring the paper by compressing the paper with rollers,
corrugating a second base material having flame resistant
properties for the spacing members, and bonding the corrugated
second base material to the first base material having the moisture
absorbent.
2. A method of manufacturing a heat exchanger of the type in which
partition members respectively separated from each other by a
spacing maintained by a spacing member to facilitate circulation of
two different air flows, with total enthalpy heat exchange
occurring between said two air flows via said partition members,
wherein the method comprises the steps of: applying a coating
solution comprising a moisture absorbent, polyvinyl alcohol and no
flame retardant to one side of a first base material for the
partition members, the base material prepared by wet beating to
obtain a fine hydrophilic fiber, making a paper in a warm water
using the fine hydrophilic fiber, rolling a wet paper with a
moisture content of 15 to 25% and subsequently calendaring the
paper by compressing the paper with rollers, corrugating a second
base material having flame resistant properties for the spacing
members, and bonding the corrugated second base material to the
first base material having the moisture absorbent.
3. The method according to claim 1, wherein said moisture absorbent
is lithium chloride.
4. The method according to claim 2, wherein said moisture absorbent
is lithium chloride.
5. The method according to claim 1, wherein a thickness of said
first base material is within a range from 10 micron to 50
micron.
6. The method according to claim 2, wherein a thickness of said
first base material is within a range from 10 micron to 50
micron.
7. The method according to claim 1, wherein air permeability (JIS b
8117) of said partition members is at least 200 seconds/100 cc.
8. The method according to claim 1, wherein the fine hydrophilic
fiber comprises cellulose fiber.
9. The method according to claim 1, wherein said second base
material having flame resistant properties contains guanidine
sulfamate.
10. The method according to claim 2, wherein air permeability (JIS
P 8117) of said partition members is at least 200 seconds/100
cc.
11. The method according to claim 2, wherein the fine hydrophilic
fiber comprises cellulose fiber.
12. The method according to claim 2, wherein said second base
material having flame resistant properties contains guanidine
sulfamate.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of application Ser. No.
10/189,556, filed Jul. 8, 2002, the contents of which are
incorporated herein by reference, which in turn claims priority to
Japanese Application No. 2001-351213, filed Nov. 16, 2001.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a heat exchanger and a heat
exchange ventilator which a laminated structure for performing heat
exchange between fluids and used mainly in the field of air
conditioning.
[0004] 2. Description of the Related Art
[0005] In recent years, air conditioning devices such as heaters
and coolers have developed considerably and have also become more
widely used, and as they living spaces using air conditioners have
expanded, there has been an associated increase in awareness of the
importance of heat exchangers for air conditioning devices capable
of recovering heat and humidity during the ventilation process.
Conventional air conditioning heat exchangers such as those
disclosed in Japanese Patent Publication No. Sho 47-19990 and
Japanese Patent Publication No. Sho 51-2131 are in widespread
use.
[0006] All of these conventional heat exchangers employ a basic
structure in which partition plates which transfer heat and are
moisture permeable are separated using spacer plates, and a
plurality of the layers are then superposed with a predetermined
spacing between the layers. The partition plates are square flat
plates, whereas the spacer plates are corrugated plates formed in
either a sawtooth wave shape or a sine wave shape which in a
projection plane thereof matches the partition plates.
[0007] Furthermore, each of the spacer plates is held between the
adjacent partition plates so that the formation directions of the
corrugations of the spacer plates alternately cross at an angle of
either 90 degrees or an angle close to 90 degrees. The fluid
passages of the dual system are formed so that the first air flow
and the second air flow are separated, and the fluid passages
running through the respective layers each comprising the spacer
plate and the partition plate are formed with alternating
orthogonality.
[0008] The properties required for the partition plates of a heat
exchanger are a low degree of air permeability and a high level of
moisture permeability. This is because in order to ensure that,
during operation of the heat exchanger, heat exchange of both
sensible heat and latent heat can be performed concurrently, with
no mixing between the external fresh air drawn into the room from
outside, and the foul air being discharged outside form inside the
room, it is necessary that water vapor be able to migrate
efficiently between the intake air and the exhaust air.
[0009] Examples of partition plate materials capable of coping with
these demands include the gas shielding materials disclosed in
Japanese Patent Publication No. Sho 58-46325. These materials are
obtained by impregnating or coating a porous member with a water
soluble polymer material including a halogenated lithium as a
moisture absorbent. Furthermore, Japanese Patent Publication No.
Sho 53-34663 discloses a method of improving the flame retardation
by mixing, where necessary, a guanidine based flame retardant with
the water soluble polymer material before the impregnation or
coating process.
[0010] In a heat exchanger comprising partition plates constructed
of the above type of moisture permeable gas shielding material
formed by impregnating or coating a porous member with a water
soluble polymer material, a problem arises in that under conditions
of high temperature and high humidity, such as those encountered in
summer, moisture absorption by the partition plates may cause a
portion of the water soluble polymer material to dissolve,
resulting in a blocking phenomenon and causing the material to
break or tear during rewinding operations such as corrugating.
Furthermore, this type of heat exchanger is produced by laminating
a plurality of heat exchanger structural members together, with
each structural member comprising a single faced corrugated
structure obtained by corrugating and bonding the material of the
spacer plate to the material of the partition plate.
[0011] The corrugation process is centered around upper and lower
gear shaped corrugators which rotate and intermesh with each other
and which are used for forming the spacer plate, and a press roller
for pressing the partition plate material onto the spacer plate
material while rotating. In order to ensure the corrugated shape of
the spacer plate, the upper and lower corrugators and the press
roller are normally maintained at a high temperature of at least
150.degree. C. Consequently, a portion of the water soluble polymer
material of the partition plate material tends to melt with the
heat from the press roller and fuse to the press roller. Although
this fusion of the partition plate material to the press roller can
be prevented by lowering the temperature of the press roller,
lowering the temperature can cause a collapse of the corrugated
shape, making the product unusable as a heat exchanger structural
member.
[0012] In order to overcome this problem, conventionally, the
temperature of the press roller and the upper and lower corrugators
is adjusted to a temperature at which fusion is unlikely to occur,
and the feed speed is lowered to prevent any collapse of the
corrugations. As a result, the productivity drops significantly,
and the production costs increase. Furthermore, heat exchangers
produced using a partition plate formation method which requires no
chemical processing, such as those disclosed in Japanese Patent
Application No. Hei 5-109005 and Japanese Patent Application No.
Hei 5-337761, are also in widespread use.
[0013] In a device of the type in which two different air flows are
separated by partition plates, and heat exchange of sensible heat
and latent heat of these two air flows occurs through the partition
plates, the partition plates are formed from a porous sheet onto
one side of which is formed a composite moisture permeable film
comprising a thin film of a water insoluble hydrophilic polymer
which is permeable to water vapor. Consequently, there is no
deformation of the device even when used in an environment which
suffers repeated dew condensation, and a total enthalpy heat
exchanger can be provided which suffers no deterioration in
performance, even with extended use. Moreover, because the
hydrophilic polymer thin film is insoluble in water, it does not
mobilize and flow, and so deterioration in performance with time
does not occur.
[0014] In those cases where a resin film such as that described
above is used for the partition plates, a base material to which
the resin is applied is necessary, and so the total thickness of
the partition plate increases, and as a result, the moisture
permeability of the plate decreases.
[0015] Furthermore, mixing a moisture absorbent with the resin
during film formation in order to improve the moisture permeability
results in unsatisfactory film formation, and attempts to
impregnate or coat a completed film with a moisture absorbent do
not allow the addition of the required amount of moisture
absorbent.
[0016] Furthermore, another problem associated with a highly
moisture permeable resin film is that it is too expensive when
compared with one employing a porous base such as paper.
SUMMARY OF THE INVENTION
[0017] Accordingly, the present invention has been designed to
overcome the conventional problems described above, and it is an
object to provide a heat exchanger and a heat exchange ventilator
which are capable of realizing a high degree of humidity exchange
efficiency at a low cost.
[0018] The present invention provides a heat exchanger in which
partition members respectively separated from each other by a
spacing maintained by one of spacing members facilitate circulation
of two different air flows, with total enthalpy heat exchange
occurring between the two air flows via the partition members,
wherein the partition members comprise an air shielding sheet type
material comprising a hydrophilic fiber and also including a
moisture absorbent.
[0019] Furthermore in the aforementioned heat exchanger, the air
permeability (JIS P 8117) of the partition members is at least 200
seconds/100 cc.
[0020] Furthermore in the aforementioned heat exchanger, the
primary constituent of the aforementioned hydrophilic fiber is
cellulose fiber.
[0021] Furthermore in the aforementioned heat exchanger, the
primary constituent of the aforementioned moisture absorbent is an
alkali metal salt.
[0022] Furthermore in the aforementioned heat exchanger, the film
thickness of the partition members is within a range from 10
microns to 50 microns.
[0023] Furthermore in the aforementioned heat exchanger, the
partition members include a flame retardant which does not react
with the alkali metal salt or the primary constituent of the
moisture absorbent.
[0024] Furthermore in the aforementioned heat exchanger, the
aforementioned spacing member includes a flame retardant which does
not contribute to the moisture permeability.
[0025] The present invention also provides a heat exchange
ventilator with a heat exchanger in which partition members
respectively separated from each other by a spacing maintained by
one of spacing members facilitate circulation of two different air
flows, with total enthalpy heat exchange occurring between the two
air flows via the partition members, wherein the partition members
comprise an air shielding sheet type material comprising a
hydrophilic fiber and including a moisture absorbent.
[0026] Furthermore in the aforementioned heat exchange ventilator,
the air permeability (JIS P 8117) of the partition members is at
least 200 seconds/100 cc.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a perspective view showing a heat exchanger of an
Embodiment 1 according to the present invention, FIG. 2 is a
perspective view showing the heat exchanger structural member of
the heat exchanger shown in FIG. 1, FIG. 3 is an enlarged end view
of the heat exchanger structural member shown in FIG. 2, FIG. 4 is
a structural diagram showing a single facer machine for performing
corrugation processing of the heat exchanger shown in FIG. 1, and
FIG. 5 is a perspective view showing a heat exchange ventilator
using the heat exchanger shown in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] As follows is a description of embodiments of the present
invention made with reference to the drawings.
Embodiment 1
[0029] FIG. 1 is a perspective view showing a heat exchanger of an
Embodiment 1 according to the present invention, FIG. 2 is a
perspective view showing the heat exchanger structural member of
the heat exchanger shown in FIG. 1, FIG. 3 is an enlarged end view
of the heat exchanger structural member shown in FIG. 2, and FIG. 4
is a structural diagram showing a single facer machine for
performing corrugation processing of the heat exchanger shown in
FIG. 1. This embodiment is described using as an example, a
laminated hexahedron type heat exchanger 1 suitable for air
conditioning purposes, such as that shown in FIG. 1.
[0030] The heat exchanger 1 is composed of a structure wherein thin
partition members 2 which transfer heat and are moisture permeable
are separated using spacing members 3, and a plurality of the
layers are then superposed and bonded together with a predetermined
spacing between the layers. The partition members 2 of the heat
exchanger 1 are square or rhombus shaped flat plates, and the
spacing members 3 are corrugated plates formed in either a sawtooth
wave shape or a sine wave shape with a shape in a projection plane
thereof which matches the partition members 2.
[0031] Each of the spacing members 3 is held between the adjacent
partition members 2 so that the directions at the formation
directions of the corrugations alternate at an angle of either 90
degrees or an angle close to 90 degrees. Fluid passages 4 and fluid
passages 5 are respectively formed within the layers each
comprising the spacing member 3 and the partition member 2, and are
formed with alternating orthogonality. A first air flow (a) flows
through the fluid passages 4, and a second air flow (b) flows
through the fluid passages 5.
[0032] As shown in FIG. 2 and FIG. 3, the heat exchanger 1 is
produced by laminating and bonding a plurality of heat exchanger
structural elements 6 each formed by bonding a spacing member 3 to
one side of a single partition member 2. As shown in FIG. 3, the
heat exchanger structural element 6 is produced in a continuous
manner by using a flat air shielding sheet as the partition member
2, and then bonding the spacing member 3 which forms the fluid
passages 4 or 5 to the partition member 2 using the corrugation
processing described below.
[0033] The sheet thickness of the partition member 2 should be kept
as thin as possible from the viewpoint of moisture permeability
performance, although if the sheet is too thin then tensile
strength is lower during subsequent processing, and the sheet may
tear during the processing. Taking both the moisture permeability
and tensile strength into consideration, the thickness of the
partition member 2 may preferably be from 10 to 50 .mu.m. If the
production technology stability of the paper material which
constitutes the partition member 2 is also taken into
consideration, then the lower limit becomes approximately 25
.mu.m.
[0034] In this embodiment, a paper partition member 2 with a
thickness within a range from 10 to 50 .mu.m and a basis weight of
10 to 50 (g/m.sup.2) is used. Cellulose fiber is preferably used as
the primary constituent of the hydrophilic fiber of the paper which
forms the partition member 2. In this manner, by using cellulose
fiber as the primary constituent of the hydrophilic fiber of the
paper which forms the partition member 2, the tensile strength can
be increased at low cost.
[0035] This partition member 2 is prepared by wet beating using an
alkali solution or the like to obtain a fine hydrophilic fiber,
making a paper in a warm water using the highly beaten hydrophilic
fiber, rolling a wet paper with a moisture content of 15 to 25%,
and subsequently calendaring the paper by compressing the paper
with rollers. The conditions for the respective process steps are
adjusted and combined. These processes enable a partition member 2
comprising an air shielding sheet type material to be prepared.
Furthermore, because the partition member 2 is subjected to a high
pressure at the same time as the drying process, a partition member
2 can be prepared which displays high density, good moisture
permeability and a high degree of smoothness.
[0036] If the moisture content of the paper during paper making is
too high, then blocking and tearing of the paper is more likely to
occur during rolling, whereas if the calendaring is performed on
paper with a moisture content which is too low, then the desired
high density paper is difficult to obtain. It is assumed that the
reason for this observation is that if the paper is too dry,
movement between fibers decreases and so the shift to higher
densities caused by recombination of fibers is less likely to
proceed. Taking these factors into consideration, rolling should
preferably be performed on wet paper with a moisture content during
paper making within the range from 15 to 25%.
[0037] The partition member 2 is prepared so that the porosity is
suppressed to approximately 20% to ensure an air permeability of at
least 5000 sec/100 cc. By ensuring that the air permeability is at
least 5000 sec/100 cc, the migration rate of carbon dioxide gas,
which is an important factor for a heat exchange ventilator, can be
suppressed to a value of no more than 1%. Considering the
desirability of suppressing this migration rate of carbon dioxide
gas, which is an important factor for a heat exchange ventilator,
to a value of no more than 1%, it is preferable that an air
permeability value of at least 5000 sec/100 cc is maintained. In
cases in which the migration rate of carbon dioxide gas is to be
suppressed to no more than 5%, an air permeability of at least 200
sec/100 cc is sufficient.
[0038] Because the partition member 2 is produced with a high
degree of wet beating, the cellulose fibers are short and a fuzzy
state can be produced. As a result, the fibers become very
interwoven enabling the tensile strength to be increased, and
moreover enabling a high density product to be produced on
compression. The reason why a fine hydrophilic fiber was used for
the partition member 2 is described below. Hydrophilic fibers such
as cellulose fibers form very high density products which are
impermeable to air.
[0039] As a result, it becomes very difficult for water vapor to
pass through the cavities between fibers from the high
concentration side to the low concentration side. It is thought
that any such migration occurs through attraction by hydroxyl
groups on the fiber surface, migration through the fiber to the low
concentration side according to the laws of diffusion, and
subsequent vaporization. Due to this principle, if the material
does not include a large quantity of hydroxyl groups, then the
moisture permeability will be lost, in a similar manner to resin
films such as polyethylene. Accordingly, the partition member 2
must utilize hydrophilic fibers of a material which includes a
large quantity of hydroxyl groups.
[0040] In order to improve the air shielding properties, it is
preferable that the partition member 2 is compressed to a high
density. Furthermore, in preparation for the chemical impregnation
conducted in subsequent steps, artificial bonds are introduced
between fibers during the paper making process by using a
thermosetting resin such as melamine resin, urea resin or an
epoxidized polyamide resin as a wet paper strength enhancing agent.
The thus obtained partition member 2, constructed of an air
shielding sheet type material, is subsequently subjected to
immersion or coating treatment with an alkali metal salt such as
lithium chloride which functions as a moisture absorbent, and with
guanidine sulfamate which is one of the guanidine salts typically
used as paper flame retardants and which does not form a salt on
reaction with lithium chloride, with each immersion or coating
treatment using 20% by weight of the compound relative to the
weight of the sheet.
[0041] A partition member 2 constructed in this manner from an air
shielding sheet type material includes a moisture absorbent, and so
it becomes easier for the material to draw moisture in, enabling
the migration of water vapor to happen more smoothly, and as a
result the moisture permeability can be improved. Furthermore,
because the primary constituent of the moisture absorbent is an
alkali metal salt, it can be readily dissolved in water.
Consequently, the preparation of the chemicals can be performed
smoothly, the operation can be completed easily, and the washing of
the equipment is also simplified. Furthermore, because alkali metal
salts offer extremely good moisture absorption, the moisture
permeability can be improved with even small amounts of added
salt.
[0042] By using a flame retardant (such as guanidine hydrochloride
or a sulfamate based guanidine) which does not react with the
alkali metal salt or the primary constituent of the moisture
absorbent, and then incorporating this flame retardant within the
partition member 2, flame resistant properties can be conferred on
the heat exchanger 1. Moreover, chemical processing of the
partition member 2 can be completed in a single process, enabling
an improvement in operating efficiency. Examples of typically used
paper flame retardants are the guanidine salts.
[0043] Of the guanidine salts, guanidine phosphate and guanidine
sulfamate are in actual use. However, if guanidine phosphate is
used as a moisture absorbent in paper, then the thermal stability
of the flame retardant paper obtained can be unsatisfactory,
leading to a tendency for a marked color change during heat
treatment. As a result, the actual usable salts are limited, and
guanidine sulfamate is used in preference.
[0044] Furthermore, in those cases in which lithium chloride is
used as a moisture absorbent, because phosphorus is known to react
with lithium to generate a salt, phosphorus cannot be used. For the
above reasons, of the guanidine salts, either guanidine sulfamate
or guanidine hydrochloride is preferably used. The latter,
guanidine hydrochloride, has moisture absorbing properties, and so
is unsuitable as a paper flame retardant. However, in a total
enthalpy heat exchanger, because the moisture absorption is good,
guanidine hydrochloride has been used conventionally. In recent
years, however, materials including chlorine have been avoided due
to associated dioxin problems, and so there is a trend towards the
use of guanidine sulfamate.
[0045] In preparing the air shielding sheet for the partition
member 2, by carrying out flame retardant and moisture absorbent
treatments on a non-porous sheet which has been compressed to a
high density, a sheet with air shielding, moisture absorbent, and
flame retardant functions can be produced. In addition to this
partition member 2, a material 9 (paper material) of the spacing
member 3 comprising cellulose fibers as the primary constituent is
then fed through the single facer machine shown in FIG. 4 and
corrugated, producing in a continuous manner the single faced
corrugated type heat exchanger structural element 6.
[0046] The single facer machine for performing the corrugation
processing is constructed around upper and lower gear shaped
corrugators 10, 11 which rotate in mesh with each other and which
are used for forming the spacing member 3, a press roller 12 for
pressing the material of the partition member 2 onto the material 9
of the spacing member 3 while rotating, and a sizing roller 13. The
upper and lower corrugators 10, 11 and the press roller 12 are
maintained at a high temperature to enable the step-shaped
corrugations of the spacing member 3 to be more easily formed.
[0047] The sizing roller 13 applies an aqueous solvent-type vinyl
acetate based emulsion adhesive to the peaks of the corrugations of
the material 9 of the corrugated spacing member 3 being fed out of
the lower corrugator 11. The material of the partition member 2 is
fed around the press roller 12 with a moisture permeable film 8
facing outwards, and the side of the partition member 2 comprising
the moisture permeable film 8 becomes the adhesion surface with the
material 9 of the spacing member 3. By cutting the heat exchanger
structural element 6 produced in this manner, and then laminating
and bonding layers of the element together with a 90 degree
rotation in direction between the alternating layers, a heat
exchanger 1 such as that shown in FIG. 1 can be produced. Moreover,
by arranging and laminating the heat exchanger structural elements
6 so that the corrugation wave directions of the spacing members 3
are parallel, a counter flow heat exchanger can be obtained.
[0048] The feature of this method of producing a heat exchanger 1
is that a water soluble and heat fused air shielding polymer film
is not provided. As a result, within the single facer machine shown
in FIG. 4 used for conducting the corrugation processing, even if
the temperature of the upper and lower corrugators 10, 11 for
forming the corrugations and the press roller 12 is maintained at a
high temperature, the air shielding sheet used as the material for
the partition member 2 does not fuse onto the press roller 12, and
the corrugation processing can be conducted at a high temperature
which makes for easier formation of the corrugations, and with a
fast feed speed.
[0049] Furthermore, because a water soluble polymer film which
functions as an air shielding layer is not provided on the surface
of the partition member 2 as in conventional materials, the
adhesion during processing improves, and so the processing can be
conducted with a much faster feed speed than that used in the
conventional corrugation processing. As a result, the productivity
can be improved significantly. In addition, in comparison with
conventional porous paper materials, because products of the
present embodiment are subjected to high levels of beating,
although the tear strength deteriorates, an increase in bonding
strength enables an increase in the bursting strength, the tensile
strength and the folding endurance. Furthermore, even with a very
thin film the tensile strength is sufficient to endure subsequent
processing, and the conventional film thickness of approximately
100 microns can be reduced to approximately 20 microns, enabling
the moisture permeation resistance to be reduced to 1/5 of
conventional values.
[0050] FIG. 5 is a perspective view showing a heat exchange
ventilator using the heat exchanger shown in FIG. 1. This heat
exchange ventilator comprises a housing 101 with an internal inlet
port 104 and outlet port 106 on one of two opposing sides and an
external inlet port 105 and outlet port 107 on the other side,
inside of which is provided a heat exchanger 112 positioned between
the aforementioned inlet ports 104, 105 and outlet ports 107, 106,
and equipped with a supply passage 109 and an exhaust passage 108
which are positioned so as to cross one another and enable heat
exchange.
[0051] Then, within the supply passage 109 and the exhaust passage
108, which are attached to the housing 101 in a removable manner,
are provided blade casings 211 provided within the supply passage
109 and the exhaust passage 108 which house blowers 110, 111
respectively each comprising a blade 121 and an electric motor 126
for generating the supply flow and the exhaust flow respectively,
and the heat exchanger 112 for conducting heat exchange between the
aforementioned supply flow and exhaust flow which is provided so as
to be removable from an aperture 115 positioned in another side
surface of the housing.
[0052] Next is a description of the operation of this heat exchange
ventilator. In the heat exchange ventilator constructed in the
manner described above, during air conditioning ventilation using
the heat exchanger 112, by operating the respective blowers 110,
111, the internal air is drawn in via the ducting through the
internal inlet port 104 in the direction of the arrow A, passes
through the heat exchanger 112 and the exhaust passage 108 in the
direction of the arrow B, and is then blown out through the
external outlet port 107 by the exhaust blower 110 as shown by the
arrow C.
[0053] Furthermore, the external air is drawn in via the ducting
through the external inlet port 105 in the direction of the arrow
D, passes through the heat exchanger 112 and the supply passage 109
in the direction of the arrow E, is blown out through the internal
outlet port 106 by the supply blower 111 as shown by the arrow F,
and is then supplied internally via the ducting. During this time,
heat exchange occurs in the heat exchanger 112 between the exhaust
flow and the supply flow, and the heat is recovered from the
exhaust flow and used for reducing the load on the heater or
cooler. Provided a heat exchanger according to the embodiment
described above is used, the humidity exchange efficiency of the
heat exchange ventilator can be improved by approximately 10%.
Embodiment 2
[0054] In a similar manner to the Embodiment 1, this embodiment
also relates to a laminated hexahedron type heat exchanger suitable
for air conditioning purposes. With the exception of the
composition of the partition members, this embodiment is basically
the same as the Embodiment 1. Accordingly, FIG. 1 through FIG. 3
also apply to this embodiment so that those components which are
identical with those of the Embodiment 1 are designated with the
same reference numerals as those used for the Embodiment 1, and
description of those components is omitted.
[0055] In a similar manner to the Embodiment 1, the heat exchanger
1 of this embodiment comprises the structure shown in FIG. 1,
wherein the thin partition members 2 which transfer heat and are
moisture permeable are separated using the spacing members 3, and a
plurality of the layers are then superposed and bonded together
with a predetermined spacing between the layers. The partition
members 2 of the heat exchanger 1 are square or rhombus shaped flat
plates, and the spacing members 3 are corrugated plates formed in
either a sawtooth wave shape or a sine wave shape with a shape in a
projection plane thereof which matches the partition members 2.
[0056] Each of the spacing members 3 is held between the adjacent
partition members 2 so that the formation directions of the
corrugations alternate at an angle of either 90 degrees or an angle
close to 90 degrees. The fluid passages 4 and the fluid passages 5
are formed within the layers each composed of the spacing member 3
and the partition member 2, and are formed with alternating
orthogonality. The first air flow (a) flows through the fluid
passages 4, and the second air flow (b) flows through the fluid
passages 5.
[0057] As was the case for the Embodiment 1, and as shown in FIG. 2
and FIG. 3, this heat exchanger 1 is also produced by laminating a
plurality of the heat exchanger structural elements 6 each formed
by bonding the spacing member 3 to one side of the single partition
member 2. The heat exchanger structural element 6 is produced in a
continuous manner by using the similar air shielding sheet to the
Embodiment 1 as the partition member 2, performing impregnation or
coating treatment of this sheet with lithium chloride as a moisture
absorbent, and then bonding the material 9 of the spacing member 3
which forms the fluid passages 4, 5 to the thus formed air
shielding material of the partition member 2 using the corrugation
processing.
[0058] The air shielding sheet which forms the partition member 2
can be selected from the same sheets as for the Embodiment 1. In
order to further improve the moisture permeability, the
impregnation or coating is conducted using only lithium chloride as
the moisture absorbent dissolved in an aqueous solvent. Due to the
low porosity level, the air shielding sheet is poorly permeated by
chemicals, and as a result, there is a danger that large amounts of
chemicals cannot be applied. In other words, even if attempts are
made to apply large quantities of the lithium chloride moisture
absorbent in order to improve the moisture permeability, if the
moisture absorbent is applied at the same time as the flame
retardant, then the quantity of the moisture absorbent which can be
applied is insufficient.
[0059] Accordingly, by coating the air shielding sheet with only
lithium chloride as the moisture absorbent, then in comparison with
the coating build-up of lithium chloride of approximately 2
g/m.sup.2 for the Embodiment 1, an approximately two fold increase
to a coating build-up of lithium chloride of approximately 4
g/m.sup.2 can be achieved, and so the moisture permeability can be
improved even further. With regards to flame retardation, provided
a JIS A1322 compliant material known as a flame resistant paper is
used for the spacing member 3, then as an overall unit, a flame
retardant heat exchanger structural element 6 can still be
constructed.
[0060] This flame resistant paper is a paper with a thickness of 60
to 120 .mu.m, and a basis weight of 25 to 150 (g/m.sup.2) produced
by either an internal method in which fine powder of a water
insoluble flame retardant is incorporated within the paper, or a
post process method in which a water dispersion of a flame
retardant is impregnated, sprayed or coated onto a produced paper.
The air shielding sheet which forms the partition member 2 then
becomes a material with both an air shielding function and a
moisture absorption function produced by performing a moisture
absorption treatment on a non-porous sheet which has been
compressed to a high density. In addition to this partition member
2, the material 9 of the spacing member 3 comprising cellulose
fibers as the primary constituent and also having flame retardation
properties is then fed through a single facer machine and
corrugated, producing in a continuous manner the single faced
corrugated type heat exchanger structural element 6. By cutting the
heat exchanger structural element 6 produced in this manner, and
then laminating and bonding layers of the element together with a
90 degree rotation in direction between the alternate layers, a
heat exchanger 1 such as that shown in FIG. 1 can be produced.
[0061] According to this method, because a flame resistant paper
which has already undergone a flame resistant treatment is used as
the material for the partition member 2, the amount of chemical
coating required to form the moisture permeable film 8 can be
reduced from the amount used in the method relating to the
Embodiment 1, and so the productivity can be improved even further
by increasing the speed of the chemical coating within the
production process. Other effects are similar to those observed for
the Embodiment 1.
[0062] In addition, by increasing the level of beating in
comparison with conventionally used porous paper materials,
although the tear strength deteriorates, an increase in bonding
strength enables an increase in the bursting strength, the tensile
strength and the folding strength. Furthermore, even with a very
thin film the tensile strength is sufficient to endure subsequent
processing, and the conventional film thickness of approximately
100 microns can be reduced to approximately 20 microns, enabling
the moisture permeation resistance to be reduced to 1/5 of
conventional values.
[0063] Furthermore, a heat exchanger of this embodiment can also be
applied to a heat exchange ventilator of the Embodiment 1 shown in
FIG. 5. Then, provided a heat exchanger according to the embodiment
described above is used, the humidity exchange efficiency of the
heat exchange ventilator can be improved by approximately 10%.
Moreover with this embodiment, as was the case for the Embodiment
1, by laminating the cut heat exchanger structural elements 6 so
that the corrugation directions of the spacing members 3 are
parallel, a counter flow heat exchanger can be obtained.
Embodiment 3
[0064] In the heat exchanger described in the Embodiment 2 above,
there is a limit to the amount of lithium chloride moisture
absorbent that can be applied, even if the lithium chloride is
dissolved in an aqueous solvent prior to coating. Accordingly, if
the moisture absorbent and polyvinyl alcohol (PVA) are dissolved in
an aqueous solvent, with the polyvinyl alcohol acting as a binder,
then the amount of lithium chloride which can be applied can be
increased significantly. By coating only one side of an air
shielding sheet of a partition member 2 with this chemical reagent
and carrying out the corrugation processing on this chemically
coated surface, then a favorable process can be achieved in which
the PVA resin does not become sticky during the corrugation
processing.
[0065] According to this method, lithium chloride can be applied in
amounts of up to approximately 6 g/m.sup.2. Following the
completion of this coating process, and subsequent processing to
form a heat exchanger, the coated chemical solution absorbs
humidity and partially liquefies. As a result, the lithium chloride
gradually penetrates into the air shielding sheet, and the
difference in moisture permeability between the front and rear
surfaces of the sheet disappears, enabling a further improvement in
moisture permeability.
[0066] Furthermore, a heat exchanger of this embodiment can also be
applied to a heat exchange ventilator of the Embodiment 1 shown in
FIG. 5. Then, provided a heat exchanger according to the embodiment
described above is used, the humidity exchange efficiency of the
heat exchange ventilator can be improved by approximately 20%
relative to conventional devices. Moreover, with this embodiment,
as was the case for the Embodiment 1, by laminating the cut heat
exchanger structural elements 6 so that the corrugation directions
of the spacing members 3 are parallel, a counter flow heat
exchanger can be obtained.
[0067] According to the present invention, by constructing a heat
exchanger using partition members comprising an air shielding sheet
type material of a hydrophilic fiber which also includes a moisture
absorbent, a heat exchanger with a high degree of humidity exchange
efficiency and a low gas migration rate can be produced.
[0068] Furthermore, in the heat exchanger described above, by
constructing the aforementioned partition members so as to produce
an air permeability of at least 200 sec/100 cc, gas migration
through the partition members can be reduced, and so as a
ventilator, the rate of gas leakage of the supply flow into the
exhaust flow can be restricted to no more than 5%, enabling
effective ventilation to be carried out.
[0069] Furthermore, in the heat exchanger described above, by using
cellulose fiber as the primary constituent of the aforementioned
hydrophilic fiber, the device can be produced at low cost, and the
tensile strength can be increased.
[0070] In addition, in the heat exchanger described above, by using
an alkali metal salt as the primary constituent of the
aforementioned moisture absorbent, a high degree of humidity
exchange efficiency can be achieved, and the moisture absorbent can
also be readily dissolved in water, enabling an improvement in
operating efficiency.
[0071] In addition, in the heat exchanger described above, by
maintaining the film thickness of the aforementioned partition
members within a range from 10 microns to 50 microns, the moisture
permeability can be improved, and the likelihood of breaks during
processing can be reduced.
[0072] Furthermore, in the heat exchanger described above, by
constructing the aforementioned partition members so as to include
a flame retardant which does not react with the alkali metal salt
or the primary constituent of the aforementioned moisture
absorbent, chemical processing of the partition members can be
completed in a single process, enabling an improvement in operating
efficiency.
[0073] Furthermore, in the heat exchanger described above, by
constructing the aforementioned spacing members so as to
incorporate a flame retardant which does not contribute to moisture
permeability, a large amount of the moisture absorbent can be
adhered, and so a high degree of humidity exchange efficiency can
be achieved, and the operating efficiency can be improved.
[0074] According to the present invention, by constructing a heat
exchange ventilator using partition members comprising an air
shielding sheet type material of a hydrophilic fiber which also
incorporates a moisture absorbent, a heat exchanger with a high
degree of humidity exchange efficiency and a low gas migration rate
can be produced.
[0075] Furthermore, in the heat exchange ventilator described
above, by constructing the aforementioned partition members so as
to produce an air permeability of at least 200 sec/100 cc, gas
migration through the partition members of the heat exchanger can
be reduced, and so as a ventilator, the rate of gas leakage of the
supply flow into the exhaust flow can be restricted to no more than
5%, enabling effective ventilation to be carried out.
* * * * *