Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This invention relates to an exchanging member for
heat and/or moisture and, more particularly, to an exchanging
member of which form and shape can be maintained solid and
firm even when such a member is subjected to moisture by the
hygroscopic agent impregnated therein.
In the prior art, there has been provided the
moisture exchange for a rotary dehumidifier as this type of
exchanger. In the moisture-exchanger of the above mentioned
type, the basic paper usually made with asbestos fiber is
corrugated, then laminated to form a so-called asbestos fiber
lamination and impregnated with a hygroscopic agent such as
lithum chloride or the like. As shown in a drawing attached
hereto and labelled prior art, a moisture exchange of this
type is housed in a rotary of the drum shape which rotates at
a low speed. The process air is fed from one side of the
rotary to the other side thereof by using a portion of the
moisture exchanger to be dehumidified to become the dried air.
By using the other portion of the moisture exchanger, the
regeneration air which has been heated by a heater is fed
from the other side of the rotary to the first side thereof
to become the regenerated exhaust air by taking up the moisture
which has been absorbed in the moisture exchanger. Although
the moisture exchanger is dried and regenerated by the re-
generation air, it is constantly subjected to the moisture,
thereby the laminated structure tends to disintegrated to the
stage of destruction thereof in the end. The afore-mentioned
problem is not limited to such a moisture exchanging member,
but is universally encountered in other types of exchangers
such as an exchanger between moisture and heat or a heat
exchanger which is impregnated with a hygroscopic agent.
In order to solve such detrimental problems, there
has heretofore been provided a process wherein several
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chemically active inorganic substances, for instance, water
glass, are impregnated in a moisture exchanger member in a
form of an aqueous dispersion to form insoluble deposited
substances which are used as lamination frames reinforcing
the structure thereof. However, in such a case, the above
mentioned process requires various additional steps such as
the step of impregnating the water glass with aqueous dis-
persion, the step of impregnating water glass with other
agueous dispersion in order to make the water glass insoluble
salts and the step of drying, thus complicating the whole
manufacturing process.
The present invention aims at providing an exchanger
for heat and/or moisture free of the above mentioned conven-
tional technical problems and such an object of the present
invention is achieved by using as the basic paper a paper made
by mixing synthetic pulp having water repellent and thermo-
plastic properties with the basic fiber material and by coating
the said mixed paper with abrasion resistant material in the
end face of the exchanger member. This invention, in short,
comprises a laminated structure of a base paper made with
synthetic pulp having water repellent and thermo-plastic
properties and having a low melting point which is thermo-
formed into a corrugated form and further laminated, and
a hygroscopic agent which is impregnated in the said laminated
structure and is characterized in that it is housed inside
a rotor of a drum shape. This invention comprises further a
laminated structure made of a base paper made with a synthetic
pulp having water repellent and thermo-plastic properties
and having a low melting point which is thermoformed into a
corrugation and further lamina~e~, a hygroscopic agent im-
pregnated into said paper and an abrasion resistant material
coated over said basic paper in the end face of the laminated
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structure and is characterized in that it is housed inside a
rotor of a drum shape.
The invention is illustrated by way of example in
the accompanying drawings whereln:
Figure 1 is a diagrammatic view illustrating a rotor
type dehumidifier of the prior art.
Figures 2 and 3 show an embodiment according to
the present invention wherein Figure 2 is a frontal view of
the exchanger in the state it is housed inside of the rotor
and ,
Figure 3 is a cross section view along the line
III-III in Figure 2.
The basic paper to be used in the present invention
is structured by mixing synthetic pulp of a low-melting
point such as polyethylene, nylon, acryl, polyester,
polypropylene or the like which has a little hygroscopic
property but has a water repellent property as well as thermo-
plastic property on a base material of such fibers as as-
bestos fiber, cellulose fiber, glass fiber, carbon fiber,
ceramic fiber or the like. The above mixed paper is first
corrugated and then laminated to form a laminated structure
5 as shown in Figure 2. In this case the mixed base paper 4
is thermoformed in a form of corrugation, therefore, the
synthetic pulp which has been deformed by the thermoform
between the base fiber material supports the corrugated form
of the mixed base paper and further the excellent water
repellent property and structure stability of the synthetic
pulp enforces inter-fiber strength and stabilizes the
lamination structure even under a moist condition. The
laminated structure 5 is impregnated with such a hygroscopic
agent as lithium chloride, lithium bromide, silica gel,
activated alumina, molecular sieves or the like and the
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impregnation therefor may be conducted at any stage during
the manufacture of the base paper 4, either at a step before
lamlnating the base paper 4 or at a step after laminating
the structure 5.
The mixing rate of synthetic pulp and inter-fiber
strength after thermoforming and under the moist conditions
are substantially proportionate to each other. The relative
strength compared to a water-proof paper are listed in thP
table below. In the table, each sample paper weighs 80 g/m2
and ~BKP in the composition column indicates coniferous tree
breached draft pulp, NUKP coniferous tree unbreached kraft
pulp, LBKP hardwood breached pulp and synthetic pulp
polyethylene respectively.
Table
strength at moist condition made
\ fiber immersed in water for 1 hour
\ composition
\ rapture tear tensile rigidity
\ strength strength 8trength (~Gurley)
\ Kgf/cm3 L W L ~ L ¦W
_ ~ _ _ _
paper ~UKP 100% 0.42 77 94 1.08 0.47 137 72
_ _ .
mixed base NBKP 80%
paper a synthetic 0.64 75 84 1.12 0.6 ¦180 85 ,
pulp 20% r--~ _ ~ l r~~~
mixed base ~UKP 30%
paper b LBKP 40% 0.80 72 84 1.90 1.00 296 133
synthetic
pulp 30% l _
L = length W = width
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The moisture exchanging capacity of the exchanging
member, on the other hand, varies depending on the amount of
free space existing between the base fibers (i.e. the amount
of the impregnated hygroscopic agent). Therefore, the mixing
rate of the synthetic pulp is limited at its maximum so as to
secure such a free space.
When considering both the inter-fiber strength
and the inter-fiber frçe space in the mixed base paper, optimul
ratio therebetween is that the synthetic pulp is 20 to 40% ana
more preferably about 30% of the base paper in terms of weight
for an exchanging member for the moisture. In the case of
an exchanger member for heat, the ratio may be slightly bigger
than the above.
Since the chemical substance such as ureau or
phosperic compound improves flame resistance or shrink re-
sistance, dimensional stability is enhanced by impregnating
such agents, thus further improving st'ability of structure.
In the embodiment of the present invention, such an agent is
impregnated togehter with the hygroscopic agent.
The exchanging member structure and process in the
aforementioned manner is housed in a rotor 2 either in the
form of a cylinder or a radially sectioned form.
As shown by the two-dot chain line in Figure 3,
since a seal 6 is provided in the main body of a casing (not
shown) which supports rotatively the rotor 2 so as to separate
the process air A from the regeneration air C, the end face
of the exchanging member 6 constantly contacts in a slidable
manner with the seal 6. In order to prevent damages which
might be caused by above slidable contact therebetween, the
area 7 on the end face which is encircled by a broken line
in Figure 3 is coated with abrasion resistent substance such
as a rigid resin. By coating in such a manner, the contacting
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point with the seal 6 is hardened free of damages. It further
enforces the laminated structure to improve moldability under
moist condition. ~he coating with such abrasion resistant
substance may be given on the mixed base paper 4 after thermo-
formed or may be given thereon when laminated. But when coating
on laminated condition, it is necessary to provide some measure
not to close the free space between laminated layers. Due to
the coating, the end face 7 of the exchanging member 1 may
become unable to absorb moisture but such coated area is so
small that reduction in moisture absorptive capacity is
negligible. In Figures 2 and 3, the reference number 8 denotes
a rotating axis of the rotor 2, 9 an enforcing rib, 10 a rim
and 11 a pressing board.
As explained in the foregoing reference made to the
embodiment, the exchanging member according to the present
invention is structured by thermoforming a mixed base paper
which is made by mixing synthetic pulp of a low melting point
having thermo-plasticity but not much hygroscopic property
on base fiber material, thereby the laminated structure can
be retained even under moist condition because of the rigidity
and water repellent property of synthetic pulp. Since the
base paper itself has a capacity to retain the laminated
structure, this method is advantageous in that it can eliminate
additional steps such as impregnating water glass heretofore
required and that it can simplify the manufacture. By coating
the end face of the exchanging member alone, it can achieve a
higher resistance against the seal as well as enhance stability
of the lamination structure with out deteriorating the hygro-
scopic water thereof.
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