JPH11189999A - Whole heat exchanger paper and element for whole heat exchanger using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a whole heat exchanger paper improved in moisture- absorbing/releasing ability, prevented from leaching out the flame retardant therein, and raised in heat exchange efficiency through minimally reducing mixing of air to be exchanged, and to obtain an element for the whole heat exchanger by using the above paper. SOLUTION: This whole heat exchanger paper is obtained by subjecting a mixture comprising 15-85 pts.wt. of fibers for paper manufacturing, 5-35 pts.wt. of microfibrillated cellulose and 10-50 pts.wt. of moisture-absorbing/releasing powder, and as necessary, 5-35 pts.wt. of a thermofusible material, to papermaking process, followed by, as necessary, impregnating the resultant paper with a flame retardant to produce a substrate paper, which, in turn, is coated with a coating layer consisting mainly of moisture-absorbing/releasing powder and a binder so as to impart the final paper product with both moisture-absorbing/ releasing ability and flame retardancy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a total heat exchanger paper having uniform air permeability, excellent total heat exchange efficiency, and, if necessary, imparting thermoformability and shape retention, and total heat using the same. The present invention relates to an exchange element.

[0002]

2. Description of the Related Art At present, most buildings and houses are equipped with air conditioners such as air conditioners in summer and heating in winter.
You can create a comfortable environment regardless of the season.
In order to create such a comfortable environment by operating such an air conditioner, the total heat exchanger provided in the air conditioner plays a very important role. That is, the good heat exchange performance of the total heat exchanger leads to a constant and comfortable environment with low energy for a long time.

Prior to the development of the total heat exchanger, when the air conditioner was operated in a closed room, the air in the room gradually became contaminated air. I was going. That is, when the air conditioner is operated for a certain period of time in order to exchange dirty air in the room with fresh outside air, the air is opened and ventilated for a sufficient time to ventilate windows and doors.

[0004] However, such a ventilation method can certainly achieve the purpose of taking in fresh air and performing ventilation, but since a higher or lower temperature of the outside air is temporarily introduced than in a room, a set temperature is required. Extra energy was needed to adjust to humidity.

[0005] A total heat exchanger has been developed to eliminate this extra energy consumption. During cooling operation, the humidity and moisture between the humid and high temperature outside air and the discharged cold air in the room are reduced. It is intended to exchange heat and take in the cooled outside air. During the heating operation, the cool air taken in from the outside exchanges moisture and heat with the warm air in the room to be discharged, so that warm air is taken into the room. That is, the total heat exchanger is
It has a function of simultaneously performing temperature exchange (sensible heat exchange) and moisture exchange (latent heat exchange) between the discharged air and the taken-in air.

[0006] As a material to be used for the element of the conventional total heat exchanger, a material obtained by corrugating a metal material such as an aluminum foil baked with silica erosil and wound or laminated in a rotor shape is used as a basic type. It has been put to practical use until today. However, although these materials are excellent in nonflammability, the metal material itself has poor moisture absorption and desorption properties, so that a latent heat exchange rate higher than a certain level could not be obtained.

Further, when a paper material mainly composed of papermaking fibers is used for the element of the total heat exchanger, it has a higher moisture absorbing and releasing property than a metal material, so that the latent heat exchange efficiency is improved to some extent. It became possible. As a means to further increase the latent heat exchange efficiency, at present, chloride such as calcium chloride, magnesium chloride, lithium chloride, etc. is impregnated and attached to paper or a single-stage corrugated exchanger material. .

However, the element for a total heat exchanger (hereinafter, referred to as an element) molded from the paper material which has been impregnated with these chlorides has a water content due to the deliquescent of the heat exchange agent chloride. If it is significantly increased, the strength will decrease, the shape will gradually collapse, or if exposed to a high temperature and humidity environment for a long time, such as during the rainy season, chloride will elute and the latent heat exchange efficiency will decrease. In addition, there is a drawback that an accident such as burning may occur due to reduced flame retardancy.

Further, Japanese Patent Application Laid-Open No. H5-115739 discloses that a fiber or powder of a polymer compound having a moisture absorbing / releasing property such as a superabsorbent polymer compound is formed into a sheet together with a natural or synthetic fiber material. Manufacture of inorganic powders with moisture absorption and desorption properties such as sepiolite, zeolite, bentonite, attapulgite, diatomaceous earth, activated carbon, etc., together with wood pulp into paper, sheet, board shape, and manufactured with moisture absorption and desorption material subjected to corrugated processing Humidity exchangers have been proposed.
However, although it is superior in moisture absorption and desorption properties as compared with the above-mentioned material mainly composed of papermaking fibers, it is inferior in flame retardancy, so that it is limited to use in a humidity exchanger that does not require flame retardancy. It is a fact.

As a means of improving the air permeability of the base paper, there is a case where cellulose fibers are beaten to increase the density of the base paper. However, in the paper making process, fixing is performed for the purpose of retaining the moisture absorbing and releasing powder on the papermaking fibers. When the agent is added, a number of very large spider web-like flocks are formed, and there is a problem that formation is difficult to take.

[0011]

SUMMARY OF THE INVENTION The present invention relates to a base paper formed by mixing a microfibrillated cellulose, a hygroscopic powder and, if necessary, a heat-fusible substance with a slurry mainly composed of papermaking fibers. After impregnating the paper with a flame retardant, if necessary, provide a moisture-absorbing / desorbing coating layer on one or both sides of the base paper to improve moisture-absorbing / desorbing properties, prevent elution of the flame-retardant, and replace it. Total heat exchanger paper with reduced flame mixing and increased heat exchange efficiency by reducing air mixing as much as possible, maintaining heat retention properties by removing heat exchanger, and total heat exchange using the paper It is intended to provide a container.

[0012]

As a result of intensive studies, the present inventors have developed a novel total heat exchanger paper which has solved these problems and a total heat exchanger element using the same.

That is, one side of a base paper which is made by mixing papermaking fibers, microfibrillated cellulose, moisture-absorbing / desorbing powder, and, if necessary, a heat-fusible substance, and impregnating with a flame retardant if necessary. Alternatively, a coated layer (hereinafter referred to as a coated layer) mainly composed of a moisture-absorbing and desorbing powder and a binder is provided on both surfaces, and a total heat exchanger paper having moisture absorbing and desorbing properties and flame retardancy is used. The object is to obtain an element for a total heat exchanger.

[0014] The reason for using microfibrillated cellulose is that air permeability can be easily improved, and the outside air taken in from outside and the air exhausted from inside when the heat exchanger is operated become difficult to mix. That's why. In order to prevent this mixing, JIS P 811
It is preferable that the air permeability specified in 7 is 100 seconds or more. Furthermore, it is possible to promote the beating of cellulose fibers in terms of controlling the air permeability, but microfibrillation is also required due to the problems that the suitability for papermaking on a paper machine and the physical strength of the final product are reduced. The use of cellulose makes production easier.

As a means for further improving the air permeability, the above-mentioned coating layer can be provided. The coating layer not only improves the moisture absorption / release properties of the moisture and the flame retardancy, but also improves the heat exchanger operation. In addition, the outside air taken in from the outside and the air exhausted from the inside are hardly mixed due to the air blocking effect of the coating layer. In addition, by adjusting the amount of microfibrillated cellulose and the coating layer to an appropriate moisture permeability and air permeability,
It is a total heat exchanger paper with good moisture absorption and desorption properties and no air leakage.

The effect of shutting off the air will be described with reference to an example. When harmful gas mainly composed of carbon monoxide generated when the heater is operated is discharged from the indoor to the outdoor through the heat exchanger, the element is not used. Without this air blocking effect, the exhaust air would pass through the element, increasing the likelihood that carbon monoxide would mix in the air taken in.

The flame retardancy of the present invention refers to JIS A 132
2 Flame-retardant type specified in "flammability test method for thin building materials", which means that it falls under any of the first and second-class flameproofing.

[0018]

DETAILED DESCRIPTION OF THE INVENTION The papermaking fibers used in the present invention include softwood unbleached kraft pulp (NUKP), softwood bleached kraft pulp (NBKP), hardwood unbleached kraft pulp (LUKP), and hardwood bleached kraft pulp (LBK).
P), softwood bleached sulphite pulp (NBSP), thermomechanical pulp (TMP) or other wood pulp alone or as a mixture, and non-wood pulp such as hemp, bamboo, straw, kenaf pulp or cationized pulp; Modified pulp such as mercerized pulp, microfibrillated pulp,
Synthetic fibers such as rayon, vinylon, nylon, acrylic and polyester, and inorganic fibers such as glass fiber and rock wool may be used alone or in combination as needed.

The microfibrillated cellulose used in the base paper of the present invention is to break the binding of the fibrils forming the cell walls of the cellulose fibers by a strong mechanical shearing force by a method such as wet grinding. By
It is refined to the microfibril dimension, the number average fiber length is 0.05 to 0.3 mm, and the water retention value is 300% or more.

The number average fiber length specified in the present invention is K
A value obtained by integrating the total lengths of the fibers present in a certain pulp suspension from data measured by a fiber length distribution measuring device (FS-200) manufactured by AJAANI (Finland) and dividing by the number of the fibers. The ratio of the total number is also obtained from the same measuring device. LBK, a raw material for ordinary paper
P, NBKP, etc. are each 0.5 mm in number average fiber length,
It has a length of about 1 mm, and the number average fiber length is at least 0.1 even for fibrillated fibers generated by beating.
The length is about 35 mm.

The water retention value is an index of the degree of swelling of the pulp, and distinguishes the water taken in and retained in the swollen fibers from the free water existing in the fibers and between the fibers by an appropriate centrifugal force. It is a value measured based on the idea that The water retention value specified in the present invention is also a value measured by the method specified in JAPAN TAPPI No. 26 based on the same concept, and a predetermined amount of a sample mat is formed in a predetermined filter in advance and centrifuged. It shows the value when the amount of retained water is divided by the amount of absolutely dry pulp after dewatering for 15 minutes at a centrifugal force of 3000 G using a separator. Normal unbeaten pulp shows only about 90%, and beaten pulp shows only about 200%.

The method for producing the fine fibrillated cellulose used in the present invention includes a method using mechanical shearing force, for example, a method using various beating machines such as a beater, a conical refiner, a single disc refiner, and a double disc refiner, under high pressure. A method of passing a small diameter orifice, a method of applying an impact to a fiber material by rotating an impeller with a drive shaft with a bell shown in JP-A-63-256787, a sand mill disclosed in JP-A-4-194097, etc. A method using a fine pulverizer is adopted.

As raw materials of the fine fibrillated cellulose, for example, chemical pulp such as hardwood bleached kraft pulp (LBKP), softwood bleached kraft pulp (NBKP), hardwood bleached sulphite pulp (NBSP), and groundwood pulp (G
Wood pulp such as P), mechanical pulp such as thermomechanical pulp (TMP), bast fiber pulp such as mulberry, ganpi, mitsumata, non-wood pulp such as cotton pulp and hemp, and regenerated cellulose fiber are used.

The moisture-absorbing and desorbing powder used in the base paper of the present invention should be replaced with a conventionally used deliquescent heat exchanger such as calcium chloride, and may be silica gel, silica alumina gel or alumina gel. , Activated alumina, synthetic zeolite, natural zeolite, synthetic silica, acid clay, activated clay, α-sepiolite, β-sepiolite, palygorskite (attapulgite), allophane, imogonite, bentonite, diatomaceous earth, calcium silicate, activated carbon, etc. Natural and synthetic powders having characteristics can be used alone or in combination of several kinds, and the amount of use is 10 to 50 parts by weight, preferably 15 to 35 parts by weight. If the amount is less than 10 parts by weight, the amount of moisture absorbed and released becomes small,
When the amount exceeds 50 parts by weight, the amount of moisture absorption / release increases, but the latent heat exchange efficiency reaches a peak.

In the present invention, when it is necessary to integrally form parts by a heat press or to perform corrugating by a hot roll, thermoformability can be imparted by means such as internally adding, impregnating, or spraying a heat-fusible substance. The heat-fusible substance used in the present invention is indispensable for improving the moldability and heat-setting property when forming an element for a heat exchanger, and further maintaining the shape when wet, Polyolefin fibers such as polyethylene, synthetic pulp, polypropylene, etc .; microfibrillated fibers thereof; hot water dissolvable fibers such as polyvinyl alcohol fibers; low melting point heat-adhesive fibers obtained by compounding polypropylene, polyethylene, polyester, etc. , Thermoplastic elastomer, ionomer, modified ionomer, vinyl acetate copolymerized polyolefin, low density olefin, low molecular weight polyolefin, stearic acid, calcium stearate, zinc stearate, ethylene bisstearate amide, carnauba wax, microcrystalline wax, dense Polio such as wax The fins and wax emulsions and dispersions that alone or mixed use 5-35 parts by weight. When the amount is less than 5 parts by weight, the thermoformability is insufficient and the shape retention when wet is poor. When the amount is more than 35 parts by weight, the performance is excessive in terms of the thermoformability, and it becomes difficult to absorb moisture, so the latent heat exchange efficiency is reduced. Resulting in.

In the present invention, in order to impart flame retardancy to the base paper, the base paper may be subjected to a flame retardant treatment as required. As the flame retardant, those which can be dispersed in an aqueous solution or water such as guanidine sulfamate, guanidine phosphate, ammonium sulfamate, a condensed phosphate alkyl ester derivative, guanidine sulfate, ammonium phosphate, ammonium sulfate, calcium chloride, and magnesium chloride are used. it can.

Further, a paper-making auxiliary material such as starch, a sizing agent, a dye, and a pigment, and a heat-resistant auxiliary such as dicyandiamide, a methylol compound of melamine, and a methylol compound of dicyandiamide can be used in combination therewith. 5-2
By impregnating 5% by weight (based on the weight of the base paper), a flame-retardant base paper is obtained. If it is less than 5% by weight, flame retardancy is lacking, and if it is more than 25% by weight, the cost increases, which is not preferable. As the impregnation method, any of on-machine impregnation using a size press device or the like on a paper machine or impregnation using an off-machine impregnator after papermaking may be adopted.

The base paper used in the present invention is prepared by preparing a slurry mainly composed of papermaking fibers, microfibrillated cellulose, moisture-absorbing / desorbing powder, and a heat-fusible substance. It is obtained by appropriately adding a strength enhancer, a wet paper strength enhancer, a sizing agent, a colorant, a fixing agent, and the like, and making the paper with an existing paper machine.

According to the present invention, it is possible to provide a coating layer on one or both sides of the above-mentioned base paper according to the intended use, thereby imparting moisture absorption / desorption properties and flame retardancy, moderate moisture permeability and air blocking properties as a whole. I can do it.

The coating layer referred to in the present invention is mainly composed of the same inorganic material as the hygroscopic powder used for the above-mentioned base paper. It is preferred to use Also, as a filler for papermaking,
Even if clay, kaolin, talc, titanium dioxide, calcium carbonate, aluminum hydroxide, and the like are used as a mixture, they are not particularly limited without any particular problem. However, in order to improve flame retardancy, it is preferable to use together with a self-extinguishing powder such as aluminum hydroxide.

As a binder used for a paint for obtaining a coating layer, synthetic rubber latex such as SBR, MBR, acrylic emulsion, vinyl chloride emulsion,
Vinylidene chloride emulsions and their copolymerized emulsions, casein, starch, PVA, etc. are used in appropriate combinations, but are mainly made of flame-retardant vinyl chloride or vinylidene chloride emulsions or copolymers thereof with low heat generation. It is preferred to use.

A dispersing agent is added to one or two or more of the moisture absorbing and releasing powders used in the paint and dispersed in water, and then a binder is added to adjust the paint. In this case, a filler for paper making such as aluminum hydroxide is used. Water retention agents, flow improvers, fungicides, preservatives, coloring agents and the like are added as necessary. Usually, the amount of the binder is preferably 5 to 30 parts by weight based on 100 parts by weight of the powder. When the amount is less than 5 parts by weight, the required strength of the coating layer itself is hardly obtained because the amount of the adhesive in the coating layer is insufficient.
If the amount is more than the weight part, it becomes difficult to absorb moisture, so that the latent heat exchange efficiency is lowered, which is not preferable.

The coating material thus adjusted is applied to one or both sides of the base paper with a coating machine such as an air knife coater, blade coater, roll coater or the like. When a flame retardant is added to the base paper, double-sided coating is preferred to prevent elution when wet, and in this case, one side is a coated layer of the moisture-absorbing and releasing powder alone,
The other may be used as a self-extinguishing powder alone coating layer. The coating amount is preferably 5 to ²⁰ g / m ² per one side. If it is 5 g / m ² or less, the moisture absorption / release properties and flame retardancy will be poor, and if it is 20 g / m ² or more, it will be difficult to absorb moisture, and the latent heat exchange efficiency will be reduced, which is not preferable.

[0034]

EXAMPLES Example 1 50 parts by weight of softwood kraft pulp (NBKP), 20 parts by weight of hardwood kraft pulp (LBKP), microfibrillated cellulose (trade name "Selish KY-100")
S ", manufactured by Daicel Chemical Industries, Ltd.). S. F. The pulp slurry obtained by beating the mixture into silica gel powder (silica gel PA-20)
0 "(manufactured by Fuji Silysia Chemical Ltd.) in an amount of 20 parts by weight to prepare a 10% concentration slurry. The wet paper strength agent (trade name “WS-5”) is used based on the solid weight of the slurry.
00 "(manufactured by Nippon PCM Co., Ltd.) and 0.3% of a sizing agent (trade name" Size Pine K-902 ", Arakawa Chemical Co., Ltd.), and then the pH was adjusted to 8 to 10 with aqueous ammonia. Adjusted to 9. Furthermore, a high-molecular weight anionic coagulant (trade name “High Holder 351”,
After adding 0.006% (Kurita Kogyo Co., Ltd.), a long net paper machine was used to obtain a total heat exchanger paper having a basis weight of 120 g / m ² by a conventional method.

Example 2 35 parts by weight of softwood kraft pulp (NBKP), 10 parts by weight of hardwood kraft pulp (LBKP), microfibrillated cellulose ("Serish KY-100S") 2
5 parts by weight and 15 parts by weight of a heat-fusible fiber (trade name “TJ04CN”, Teijin Limited) were added to 500 ml C.I. S. F. The pulp slurry obtained by beating into F was mixed with silica gel powder (trade name “Mizukasorb S-0”, manufactured by Mizusawa Chemical Industry Co., Ltd.) 15
A 10% slurry was prepared by mixing parts by weight. The wet strength agent ("W
S-500 ") at 1% and a sizing agent (" Size Pine K-
902 ”) was added at 0.3%, and then a paper strength agent (trade name“ Neotack L-1 ”, manufactured by Nippon Shokuhin Kako Co., Ltd.) was added at 0.5% based on the weight of the solid content. After adding 0.006% of a polymer anionic coagulant (“Hi Holder 351”) to the slurry based on the weight of the solid content, the total heat exchanger paper having a basis weight of 120 g / m ^{2 was} obtained using a fourdrinier paper machine in a conventional manner. I got

Example 3 The total heat exchanger base paper having a basis weight of 120 g / m ² obtained in Example 1 was impregnated with a 15% flame retardant (trade name "Apinon 117", Sanwa Chemical Co., Ltd.) impregnation liquid. By impregnating and drying by heating, a total heat exchange paper was obtained.

Example 4 A mixture of 50 parts by weight of silica gel powder ("PA-200") and 50 parts by weight of aluminum hydroxide powder was treated with MB
15 parts by weight of R latex (trade name "Polylac 75
0 ", manufactured by Mitsui Toatsu Chemical Industry Co., Ltd.)
% Of the coating solution, and the basis weight obtained in Example 1 was 120 g.
/ The total heat exchanger base paper m ^2, and provided with a coating layer of 15 g / m ² on one side by using an air knife coater.

Example 5 A mixture of 50 parts by weight of silica gel powder ("PA-200") and 50 parts by weight of aluminum hydroxide powder was treated with MB
15 parts by weight of R latex (trade name "Polylac 75
0 ", manufactured by Mitsui Toatsu Chemical Industry Co., Ltd.)
% Of the coating solution, and the basis weight obtained in Example 1 was 120 g.
/ M ² of the total heat exchanger base paper was provided with a coating layer of 10 g / m ^{2 on} one side on both sides using an air knife coater.

Example 6 A mixture of 50 parts by weight of silica gel powder ("PA-200") and 50 parts by weight of aluminum hydroxide powder was treated with MB
After preparing a coating solution having a concentration of 43% to which 15 parts by weight of R latex (“Polylac 750”) was added, the base paper for a total heat exchanger having a basis weight of 120 g / m ² obtained in Example 2 was added to an air knife coater. Was used to provide a coating layer of 15 g / m ^{2 on} one side.

Comparative Example 1 300 ml of 45 parts by weight of softwood kraft pulp (NBKP) and 30 parts by weight of hardwood kraft pulp (LBKP)
C. S. 25 parts by weight of a silica gel powder ("silica gel PA-200") was mixed with the pulp slurry obtained by beating into F to prepare a 10% concentration slurry. The wet paper strength enhancer ("WS-5") was added to the solid content weight of the slurry.
00 ") and a sizing agent (" Size Pine K-90 ").
2 ”) was added at 0.3%, and the pH was adjusted to 8 with aqueous ammonia.
Adjusted to ~ 9. Further, the slurry was added to the polymer anionic coagulant (“High Holder 35”) based on the solid content weight.
1)) was added to obtain a total heat exchanger paper having a basis weight of 120 g / m ^{2 using} a fourdrinier paper machine in a conventional manner.

Comparative Example 2 300 parts by weight of 50 parts by weight of softwood kraft pulp (NBKP) and 45 parts by weight of hardwood kraft pulp (LBKP)
C. S. F was mixed with 5 parts by weight of a silica gel powder ("silica gel PA-200") into a pulp slurry obtained by beating into F to prepare a 10% concentration slurry. The wet paper strength enhancer ("WS-50") was added to the solid content weight of the slurry.
0 ") and 1% of a sizing agent (" Size Pine K-90 ").
2 ”) was added at 0.3%, and the pH was adjusted to 8 with aqueous ammonia.
Adjusted to ~ 9. Further, the slurry was added to the polymer anionic coagulant (“High Holder 35”) based on the solid content weight.
1)) was added to obtain a total heat exchanger paper having a basis weight of 120 g / m ^{2 using} a Fourdrinier paper machine in a conventional manner.

Comparative Example 3 40 parts by weight of softwood kraft pulp (NBKP), 27 parts by weight of hardwood kraft pulp (LBKP), and 3 parts by weight of heat-fusible fiber ("TJ04CN") were mixed with 300 ml of C.I. S. F
30 parts by weight of silica gel powder (“Mizukasorb S-0”) was mixed into the pulp slurry obtained by beating
% Slurry was prepared. Wet paper strength enhancer ("WS-500") was added to the slurry at a solids weight of 1
%, Sizing agent (“Size Pine K-902”) 0.3
%, A paper strength enhancer ("Neotack L-1") is added to the slurry at 0.5% based on the weight of the solid content. After adding 0.006% of the holder 351)), a total heat exchanger paper having a basis weight of 120 g / m ² was obtained using a fourdrinier paper machine in a conventional manner.

Using the above-described total heat exchanger paper, a heat corrugating process was performed by a corrugating machine. A total heat exchange element as shown in FIGS. 1 and 2 was prepared from the obtained corrugated product.

In Table 1, a rotor for a heat exchanger having a width of 12 cm and a diameter of 45 cm was prepared from a corrugated product having the air permeability specified in JIS P 8117 and E-stage processing of the total heat exchanger paper of Examples and Comparative Examples. The element of FIG. 2 was prepared, and the thermoformability, the total heat exchange efficiency when performing a practical test, and the mixing of air were shown. In addition, the evaluation of the thermoformability was evaluated by a circle when the moldability was good at the time of corrugating, and a cross when the shape collapsed. Total heat exchange efficiency is 1.5m / wind
It is a value at the time of seconds and a pressure loss of 5 mmHg. Efficiency is 60% or less by X, 60 to 70% is indicated by O, 70% or more is indicated by ◎, and O or more is suitable.

[0045]

[Table 1]

From the results shown in Table 1, the following was found. (1) From the air permeability of the example, the air permeability increased to 100 seconds or more by using microfibrillated cellulose even though powder was used. Generally, except for powders having very high water retention such as viscous substances, the air permeability tends to decrease when the mixing ratio of powders is increased.

(2) Regarding thermoformability, in comparison with Example 2 and Comparative Example 3 using a heat-fusible substance, Example 2 has sufficient moldability, but Comparative Example 3 has heat-fusibility. It can be seen that the moldability was insufficient due to the small amount of the reactive substance.

(3) In the evaluation of the total heat exchange efficiency, particularly the latent heat exchange efficiency was greatly affected by the content of silica gel, and only Comparative Example 2 having a small silica gel content was insufficient.
Furthermore, the combined use of the hygroscopic powder and the microfibrillated cellulose makes it possible to improve the overall exchange efficiency of the total heat exchange. The reason for this is that microfibrillated cellulose is a very fine fibrous material, so it is easy to cause a capillary phenomenon, and because of the large number of fibers, the water retention per unit weight is very high. I can guess.

(4) In the mixing of air, in the comparative example in which microfibrillated cellulose was not used, mixing of air was observed because air was very easy to pass as can be seen from the numerical value of air permeability. Was done.

[0050]

As described above, the total heat exchanger sheet of the present invention and the element for a total heat exchanger using the same have the following remarkable effects.

(1) When microfibrillated cellulose is used as a raw material, it is easy to control the air permeability.

(2) When the pulp is beaten as a means of controlling the air permeability, the formation unevenness becomes remarkable.
When C is used, a uniform paper layer can be formed.

(3) Since the total heat exchanger paper is preliminarily provided with moisture absorption / desorption properties, the latent heat exchange efficiency can be improved without using a deliquescent substance such as lithium chloride, and the strength can be improved. It is possible to manufacture a total heat exchange element having excellent shape retention without a decrease in flame retardancy.

(4) By using a heat-fusible substance, thermoforming can be easily performed by hot corrugating, heat pressing or the like.

(5) Those provided with a moisture absorbing / releasing coating layer are:
It is possible to further reduce not only the moisture absorption / release performance but also the permeability of air, thereby reducing the mixing of the air to be replaced as much as possible and improving the air purification action.

(6) Unlike a metal material such as an aluminum plate or a plastic material, it is a paper material and can be incinerated when it becomes unnecessary.

[Brief description of the drawings]

FIG. 1 is an example of a total heat exchanger element obtained by laminating a total heat exchanger sheet alternately vertically and horizontally after corrugating.

FIG. 2 shows an example in which a total heat exchanger sheet is corrugated and then wound in a rotor shape to form a total heat exchanger element.

[Explanation of symbols]

 1 Element for stacked type total heat exchanger 2 Element for rotor type total heat exchanger

Claims (9)

[Claims] Claims: 1. A total heat exchanger paper comprising papermaking fibers, microfibrillated cellulose and moisture-releasing powder as main components. 2. A total heat exchanger paper comprising, as main components, papermaking fibers, microfibrillated cellulose, moisture-releasing powder and a heat-fusible substance. 3. The total heat exchange according to claim 1, wherein the papermaking fiber comprises 15 to 85 parts by weight, the microfibrillated cellulose comprises 5 to 35 parts by weight, and the moisture releasing powder comprises 10 to 50 parts by weight. Container paper. 4. A papermaking fiber comprising 15 to 80 parts by weight, microfibrillated cellulose 5 to 30 parts by weight, a moisture releasing powder 10 to 50 parts by weight, and a heat-fusible substance 5 to 35 parts by weight. The total heat exchanger paper according to claim 2, characterized in that: 5. A total heat exchanger sheet according to claim 1, wherein the total heat exchanger sheet is impregnated with a flame retardant. 6. A total heat exchanger paper characterized in that the total heat exchanger paper according to claim 1 is provided with a moisture absorbing / releasing coating layer. 7. The total heat exchanger paper is impregnated with a flame retardant in an amount of 5 to 25% by weight based on the weight of the base paper, and then provided with a moisture absorbing / releasing coating layer of 5 to 20 g / m ² on one side. The total heat exchanger paper according to claim 6, wherein 8. The total heat exchange according to claim 6, wherein the powder used for the moisture absorbing / releasing coating layer is a mixture of silica gel and aluminum hydroxide. Container paper. 9. An element for a total heat exchanger, wherein the paper for a total heat exchanger according to claim 1 is used.