JP2021055873A - Heat exchanger, base paper for interval member, and method for manufacturing base paper for interval member - Google Patents

Abstract

To provide a heat exchanger capable of prevent a moisture absorption effect from deteriorating with time, and enabling efficient heat exchange for a long period, base paper for an interval member used in the heat exchanger, and a method for manufacturing the base paper for an interval member.SOLUTION: A heat exchanger uses: a partition member 2 that comprises a paper base material whose main component is cellulose fiber, and one or more kinds selected from the group consisting of calcium chloride, magnesium chloride and lithium chloride held on the paper base material, and in which no other flame retardant is contained; and an interval member 3 that comprises a paper base material whose main component is cellulose fiber, and one or more kinds selected from the group consisting of calcium chloride and magnesium chloride held on the paper base material, and in which no other flame retardant is contained.SELECTED DRAWING: Figure 1

Description

The present invention relates to a heat exchanger, a base paper for spacing members, and a method for manufacturing base paper for spacing members. More specifically, to a heat exchanger that supplies both fresh outside air and exchanges both sensible heat (temperature) and latent heat (humidity) when discharging dirty air in the room, and this heat exchanger. The present invention relates to a base paper for a spacing member used and a method for manufacturing a base paper for a spacing member.

Conventionally, as a device capable of ventilating without impairing the effects of cooling and heating, a heat exchanger that exchanges heat between supply air and exhaust during ventilation has been used.
As the heat exchanger, a plurality of partition members are laminated via a spacing member, and the air supply path for introducing the outdoor air into the room and the exhaust path for discharging the indoor air to the outside are partitioned by the partition member. Things are widely adopted.

This partition member is required to have high moisture permeability because it exchanges heat of latent heat (humidity) at the same time as sensible heat (temperature) while blocking the ventilation of the air supply path and the exhaust path. Therefore, as the partition member, a paper base material holding a hygroscopic agent is used.
When the partition member holds the moisture absorbing agent, it is easy to absorb the moisture inside, so that the water vapor can move smoothly and the moisture permeability is improved.

Further, since the heat exchanger is required to have flame retardancy, the partition member and the interval member are made to hold the flame retardant. Patent Document 1 discloses a heat exchanger in which a flame retardant is held in a spacing member so that a large amount of hygroscopic agent can be held in the partition member.
Known hygroscopic agents include water-soluble salts such as calcium chloride and lithium chloride, and water-insoluble or sparingly water-soluble salts such as silica gel and zeolite. In particular, calcium chloride is said to be excellent in hygroscopic effect and economic efficiency. (Patent Document 2).

Japanese Unexamined Patent Publication No. 2007-147279 Japanese Unexamined Patent Publication No. 2017-179613

However, a heat exchanger using calcium chloride as a hygroscopic agent may not be able to efficiently exchange heat due to a decrease in the hygroscopic effect over time.
In view of the above circumstances, the present invention presents a heat exchanger in which the moisture absorption effect does not easily decrease over time and efficient heat exchange for a long period of time, a base paper for a spacing member used in the heat exchanger, and a spacing member. An object of the present invention is to provide a method for producing a base paper.

In order to achieve the above problems, the present invention has adopted the following configuration.
[1] A plurality of partition members and a plurality of interval members that form a flow path between the plurality of partition members and maintain a distance between the partition members are provided.
The plurality of partitioning members include one or more selected from the group consisting of a paper base material containing cellulose fibers as a main component and calcium chloride, magnesium chloride and lithium chloride held on the paper base material, and other flame retardants. Does not include
The plurality of spacing members include one or more selected from the group consisting of a paper base material containing cellulose fibers as a main component and calcium chloride and magnesium chloride held on the paper base material, and do not contain any other flame retardant. A heat exchanger characterized by that.
[2] The heat exchanger according to [1], wherein the plurality of spacing members hold at least one selected from the group consisting of calcium chloride and magnesium chloride on at least both surfaces of the paper substrate.
[3] The heat exchanger according to [1] or [2], wherein the plurality of partition members have a density of 0.9 to 1.2 g / cm ^3.
[4] The flow path is composed of a first flow path and a second flow path formed in directions intersecting each other.
The heat exchanger according to any one of [1] to [3], wherein the first flow path and the second flow path are adjacent to each other with the partition member interposed therebetween.
[5] Used as the spacing member in a heat exchanger including a plurality of partitioning members and a plurality of spacing members that form a flow path between the plurality of partitioning members and maintain a spacing between the partitioning members. It is a base paper for interval members
The interval is characterized by containing one or more selected from the group consisting of a paper base material containing a cellulose fiber as a main component and calcium chloride and magnesium chloride held on the paper base material, and not containing any other flame retardant. Base paper for members.
[6] The base paper for a spacing member according to [5], which holds at least one selected from the group consisting of calcium chloride and magnesium chloride on at least both surfaces of the paper base material.
[7] Used as the spacing member in a heat exchanger including a plurality of partitioning members and a plurality of spacing members that form a flow path between the plurality of partitioning members and maintain a spacing between the partitioning members. This is a method for manufacturing base paper for spacing members.
A paper substrate containing cellulose fibers as a main component is coated or impregnated with a solution containing one or more selected from the group consisting of calcium chloride and magnesium chloride and containing no other flame retardant. A method for manufacturing base paper for members.
[8] The solution is applied or impregnated so that the retention amount of one or more selected from the group consisting of calcium chloride and magnesium chloride is 3 to ^{15 g per 1 m 2 of the base paper for spacing members, according to [7].} Method of manufacturing base paper for spacing members.

The heat exchanger of the present invention does not easily lose its hygroscopic effect over time, and can efficiently exchange heat for a long period of time. Further, the base paper for the interval member of the present invention can be used for the heat exchanger of the present invention, and according to the method for producing the base paper for the interval member of the present invention, the base paper for the interval member of the present invention can be produced.

It is a perspective view which shows the heat exchanger which concerns on one Embodiment of this invention.

[Heat exchanger]
FIG. 1 is a perspective view showing a heat exchanger 1 according to an embodiment of the present invention. The heat exchanger 1 is composed of a plurality of partition members 2 and a plurality of interval members 3 that form a flow path between the plurality of partition members 2 and maintain a distance between the partition members 2.
The partition member 2 is formed as a flat plate such as a square or a rhombus, and the interval member 3 is formed on a corrugated plate having a sawtooth or sinusoidal waveform whose projected plane shape matches the partition member 2. For example, it has a shape like the core of corrugated cardboard and is formed by corrugated processing.
The corrugated ridge line portion and valley line portion of the interval member 3 are adhered to the partition member 2.

The spacing member 3 is adhered to the partition member 2 with the direction of the corrugated ridge line being the first direction a on one surface side of the partition member 2, and the corrugated ridge line on the other surface side. Is adhered to the partition member 2 in a state where the direction of is the second direction b.
For bonding, a method using an adhesive or a thermal bonding method using no adhesive can be used, but the method using an adhesive is preferable because the spacing member 3 and the partition member 2 can be firmly bonded to each other. As the adhesive, known adhesives such as polyvinyl alcohol-based adhesives and polyvinyl acetate-based adhesives can be used. A hygroscopic agent can be blended in the adhesive. Examples of the hygroscopic agent that can be blended include calcium chloride, magnesium chloride, lithium chloride and the like. Further, a fungicide, a thickener and the like can be added to the adhesive.
The interval member 3 whose corrugated ridge line direction is the first direction a and the interval member 3 whose second direction b where the corrugated ridge line direction intersects the first direction a are partition members 2. They are adjacent to each other with a gap in between, and are stacked alternately.

A plurality of first flow paths 4 along the first direction a are formed between the interval member 3 whose corrugated ridge line direction is the first direction a and the partition members 2 on both sides. Further, a plurality of second flow paths 5 along the second direction B are formed between the interval member 3 whose corrugated ridge line direction is the second direction B and the partition members 2 on both sides. There is.

The spacing member 3 in which the direction of the corrugated ridge is the first direction a and the spacing member 3 in which the direction of the corrugated ridge is the second direction b are alternately laminated while sandwiching the partition member 2. Therefore, the first flow path 4 and the second flow path 5 are also formed alternately along the thickness direction (vertical direction in FIG. 1).
For example, air is ventilated through the first flow path 4 and exhaust gas is ventilated through the second flow path 5, and heat exchange is performed between the supply air and the exhaust gas via the partition member 2. There is.

The intersection angle between the first direction a and the second direction b is 90 degrees or an angle close to 90 degrees depending on the shape of the partition member 2. For example, when the partition member 2 is square, the intersection angle between the first direction a and the second direction is preferably 90 degrees, and when the partition member 2 is a rhombus, the first direction a and the second direction The intersection angle of (b) is preferably close to the angle at which the lines connecting the midpoints of the opposing sides of the partition member 2 intersect.

The average pitch of the waveform of the spacing member 3 is preferably 1.5 to 8 mm, more preferably 2 to 7 mm, and even more preferably 4 to 6.5 mm. The average height of the waveform of the spacing member 3 is preferably 1 to 5 mm, more preferably 1.3 to 4 mm, and even more preferably 1.5 to 3.5 mm.
When the average pitch and the average height of the waveform of the interval member 3 are equal to or more than the preferable lower limit values, it is easy to secure the ventilation of the first flow path 4 and the second flow path 5. When the average pitch and the average height of the waveform of the interval member 3 are equal to or less than the preferable upper limit values, it is easy to secure the contact between the gas passing through the first flow path 4 and the second flow path 5 and the partition member 2, and heat is generated. It is easy to secure the efficiency of exchange.

In the heat exchanger 1, the partition member base paper and the corrugated spacing member base paper are alternately bonded to the partition member base paper on both sides with the corrugated ridge line portion and valley line portion of the spacing member base paper. It can be manufactured by laminating it in a predetermined shape and then cutting it into a predetermined shape.
At the time of laminating, the partition member is divided into a base paper for an interval member in which the direction of the corrugated ridge is the first direction a and a base paper for the interval member in which the direction of the corrugated ridge is the second direction b. Insert the base paper and repeat alternately.

[Base paper for partition members]
The partition member 2 contains one or more selected from the group consisting of a paper base material containing cellulose fibers as a main component and calcium chloride, magnesium chloride and lithium chloride held on the paper base material, and also contains a flame retardant. Absent.
Therefore, the base paper for the partition member constituting the partition member 2 is also one or more selected from the group consisting of a paper base material containing cellulose fibers as a main component and calcium chloride, magnesium chloride and lithium chloride held on the paper base material. Contains, and does not contain other flame retardants.

The paper base material contains cellulose fibers as a main component. "Containing as a main component" means that the ratio to the entire paper base material is 50% by mass or more. The paper substrate is typically composed of pulp containing cellulose fibers. Examples of pulp containing cellulose fibers include wood pulp and non-wood pulp. Examples of wood pulp include softwood pulp and hardwood pulp. Examples of non-wood pulp include hemp pulp, kenaf pulp, bamboo pulp and the like.
The wood pulp may have undergone a cooking process and / or a bleaching process. Generally, wood pulp is used by subjecting it to various cooking steps and bleaching steps in order to remove components other than cellulose from the raw material wood. In the present invention, the cooking step and the bleaching step are not particularly limited, and a known method can be used as appropriate.
As the pulp, softwood pulp is preferable, and softwood kraft pulp (NBKP) is more preferable, because the strength of the base paper and the CO _{2 barrier property are further enhanced.}
These pulps may be used alone or in combination of two or more.

The paper substrate may further contain fibers other than the cellulose fibers. Examples of other fibers include synthetic fibers such as rayon fiber, polyethylene fiber, polypropylene fiber and polyester fiber.
The paper base material may contain an internal chemical such as a sizing agent, a paper strength enhancer, and a colorant. As the internal medicine, known ones can be used.

Since calcium chloride, magnesium chloride and lithium chloride all function as hygroscopic agents, retaining one or more of them improves the moisture permeability of the partition member 2.
Further, since calcium chloride and magnesium chloride have flame retardancy, the flame retardancy of the partition member 2 is improved when one or more of them are retained.

The distribution state of calcium chloride, magnesium chloride, and lithium chloride in the base paper for the partition member is not particularly limited, but at least on both surfaces of the paper base material from the viewpoint of easily improving the moisture permeability of the partition member 2. Or it is preferable that all of them are retained.
The state of being held on the surface of the paper base material may be a state of being attached to the surface of the paper base material, or a state of being held in the gaps between fibers near the surface of the paper base material. Further, it may include both a state of being attached to the surface of the paper base material and a state of being in the gap between the fibers near the surface of the paper base material.

When a part or all of calcium chloride, magnesium chloride, and lithium chloride in the base paper for the partition member is held in a state of being inserted into the gaps between the fibers of the paper base material, the concentration of the paper base material in the thickness direction is uniform. However, it may have a concentration gradient such that the concentration decreases from the surface of the paper base material toward the inside. From the viewpoint that the moisture permeability of the partition member 2 can be easily improved, it is preferable to have a concentration gradient such that the concentration decreases from the surface of the paper base material toward the inside.

The retention amount of one or more selected from the group consisting of calcium chloride, magnesium chloride and lithium chloride ^{is preferably 2 to} 15 g per 1 m 2 of base paper for partition members, preferably 3 to 10 g, in terms of anhydride. More preferable. Further, 5 to 30% by mass, more preferably 10 to 25% by mass, in terms of anhydride, is preferable with respect to the total mass of the base paper for the partition member.
In particular, when calcium chloride is retained, the content thereof is preferably 5 to 30% by mass, more preferably 10 to 20% by mass, in terms of anhydride, based on the total mass of the base paper for partition members. When the content of calcium chloride is at least the lower limit of the above range, the moisture absorption / desorption performance and flame retardancy are more excellent. When the content of calcium chloride is not more than the upper limit of the above range, dripping due to excessive water content at high humidity is unlikely to occur.

Examples of the flame retardant that should not be contained in the base paper for the partition member include ammonium salt-based flame retardants such as diammonium phosphate, ammonium chloride, and ammonium sulfate.
By not containing these components, the hygroscopic effect of calcium chloride and the like over time is less likely to decrease, and efficient heat exchange for a long period of time becomes possible. When these components are contained, the hygroscopic effect of calcium chloride or the like over time is considered to be due to the reaction of calcium chloride or the like with these components to form a complex.

The base paper for the partition member may hold a humidity control agent. By retaining the temperature control agent, dew condensation is less likely to occur.
The temperature control agent preferably contains a latent heat storage component. The latent heat storage component has a property of absorbing heat (heat storage) when the phase changes (melting) from the solid state to the liquid state, and dissipating heat by changing the phase (solidifying) from the liquid state to the solid state. Due to this property, the temperature around the temperature controller changes from a temperature lower than the melting point (or freezing point) of the latent heat storage component to a temperature higher than that, or from a temperature higher than the melting point (or freezing point) to a temperature lower than that. At that time, heat absorption or heat dissipation occurs at a temperature near the melting point (or freezing point) of the latent heat storage component, and the temperature is kept constant.

The melting point of the latent heat storage component is preferably 10 to 35 ° C, more preferably 20 to 35 ° C. When the melting point of the latent heat storage component is within the above range, when heat is exchanged between the indoor air and the outdoor air via the partition member 2, the partition is formed even if the temperature difference between the air is large. Condensation is unlikely to occur on the surface of the member 2.
Specific examples of the latent heat storage component, holding modes, and the like are the same as those described in Patent Document 2.

If necessary, the base paper for partition members may further contain other additives as long as the effects of the present invention are not impaired. Examples of other additives include fungicides, polymer compounds and the like.
Other additives may be contained in the base paper for partition members in a state of being attached to the surface of the paper base material, or may be contained in the base paper for partition members in a state of being in the gaps between the fibers of the paper base material. Alternatively, it may be contained in the base paper for the partition member in both a state of being attached to the surface of the paper base material and a state of being in the gap between the fibers of the paper base material.

The base paper for a partition member may have a coating layer containing a polymer resin on one side or both sides of a paper base material in order to improve gas barrier properties. Examples of the polymer resin used for such a purpose include polyvinyl alcohol (PVA).
The coating layer is formed by applying a coating liquid containing a polymer resin to a paper substrate and drying it. Since the paper substrate is porous, the coating layer is usually at least partially present in the gaps between the fibers below the surface of the paper substrate. A part of the coating layer may be present on the surface of the paper substrate.

The base paper for partition members preferably has a density of 0.9 to 1.2 g / cm ³ , more preferably 0.95 to 1.15 g / cm ³ , and more preferably 1.0 to 1.1 g / cm. It is more preferably ^3.
When the density of the base paper for the partition member is at least the lower limit of the preferable value, the gas barrier property is improved, and the thickness can be reduced, so that the thermal conductivity is increased and the heat exchange efficiency is improved. When the density of the base paper for the partition member is not more than the upper limit of the preferable value, it is possible to maintain an appropriate water retention in the gap between the fibers.
The density of the base paper for partition members is calculated from the measured values of thickness and basis weight in accordance with JIS P 8118 (1998).

Moisture permeability of the base paper for the partition member is preferably at 1,000g ^/ (m 2 · 24h) or more, more preferably 1,200 ^(m 2 · 24h) or more, 1,500 ^{(m 2} · 24h) or more is more preferable.
When the moisture permeability of the partition member base paper is at least the above lower limit value, the efficiency of exchanging latent heat (humidity) between supply air and exhaust air is excellent.
For the moisture permeability of the base paper for partition members, a moisture permeability test was conducted in accordance with JIS Z 0208 (1976) except that the temperature and humidity conditions were changed to a temperature of 20 ° C and a relative humidity (RH) of 65%, and one hour after the start of the test. When the mass increment (g) is A and the mass increment (g) from 1 hour to 2 hours after the start of the test is B, it is converted from the mass increment C per hour calculated by the following formula (1). .. Specifically, the mass increment C per hour is multiplied by 24 to obtain a value per 24 hours (g / 24h), and the value is ^{divided by the area (m 2} ) of the base paper for the partition member to obtain the moisture permeability (g). / ^(m 2 · 24h)) is required.
Mass increment per hour C = (A + B) / 2 ... (1)

The air permeability of the base paper for the partition member is preferably 1,000 seconds or more, and more preferably 7,000 seconds or more. When the air permeability of the partition member base paper is at least the above lower limit value, it is possible to sufficiently suppress the mixing of air supply and exhaust.
The air permeability of the base paper for partition members is determined by the Japan TAPPI pulp and paper test method No. It is measured according to the Wang Lab's air permeability method of 5-2: 2000.

The basis weight of the base paper for the partition member is preferably 20 to 80 g / ^{m 2,} and more preferably 30 to 60 g / ^{m 2.} When the basis weight of the base paper for the partition member is not less than the lower limit of the above range, the mechanical strength and the gas barrier property are excellent. When the basis weight of the base paper for the partition member is equal to or less than the upper limit of the above range, the heat transfer property is excellent, the weight of the partition member 2 formed from the base paper for the partition member is reduced, and the partition member 2 in the heat exchanger is reduced in weight. The number of laminated stages can be increased, and the heat exchange efficiency can be further improved.
The basis weight of the base paper for partition members is measured in accordance with JIS P 8124 (2011). The basis weight of the paper base material can be obtained in the same manner.

The thickness of the base paper for the partition member is preferably 0.01 to 0.1 mm, more preferably 0.03 to 0.05 mm. When the thickness of the base paper for the partition member is at least the lower limit of the above range, the mechanical strength and the gas barrier property are excellent. When the thickness of the base paper for the partition member is equal to or less than the upper limit of the above range, the heat transfer property is excellent, the weight of the partition member 2 formed from the base paper for the partition member is reduced, and the partition member 2 in the heat exchanger is reduced in weight. The number of laminated stages can be increased, and the heat exchange efficiency can be further improved.
The thickness of the base paper for the partition member is measured according to JIS P 8118 (2014). The thickness of the paper base material can be obtained in the same manner.

[Manufacturing method of base paper for partition members]
The base paper for a partition member is a solution containing one or more selected from the group consisting of calcium chloride, magnesium chloride and lithium chloride in a paper base material and containing no other flame retardant (hereinafter, may be referred to as a "partition member solution"). Yes) can be produced by coating or impregnating.
If necessary, the solution may further contain a humidity control agent, other additives, and the like.

The paper substrate can be produced by making a papermaking material containing cellulose fibers.
The papermaking raw material may contain other fibers and internal chemicals, if necessary.
Papermaking as a raw material for papermaking can be carried out by using a known method as appropriate.

When the cellulose fibers are pulp, the pulp is beaten and subjected to a papermaking process, depending on the type of paper used. The beating process of pulp can be carried out by a known method, and for example, a beating device such as a DDR (double disc refiner) is preferably used.
As the pulp beating process proceeds, the pulp fibers generally become more supple, making it easier to obtain a high-density paper substrate. The densification of the paper base material improves the gas barrier property. Therefore, the pulp used in the production of the paper base material is preferably beaten. On the other hand, if the pulp beating process is advanced, the filtrate becomes worse and the operation efficiency is lowered. Therefore, the degree to which the pulp is beaten (beating degree) is appropriately selected in consideration of the strength, gas barrier property, basis weight, operating efficiency, etc. of the target paper base material.

The degree of beating of the pulp is preferably 100 to 600 mL, more preferably 150 to 500 mL, as the following irregular freeness. When the irregular freeness is not more than the upper limit of the above range, the retention of calcium chloride and the like and the gas barrier property are more excellent. If the irregular freeness is equal to or higher than the lower limit of the above range, the operation efficiency is good.

Anomalous Freeness: Anomalous freeness is a measurement method based on JIS P 811-2 (2012) "Pulp-Water Freeness Test Method-Part 2: Canadian Standard Freeness Method", but the amount of pulp used is The absolute dry mass is equivalent to 0.3 g, and the perforated sieve plate to be mounted on the Canadian standard freshness tester is a measurement method using an 80 mesh sieve plate made of stainless wire. Specifically, the dissociated pulp was diluted with water so as to have a solid content concentration of 0.030% by mass. The sample temperature was adjusted to 20 ° C., and 1000 mL of the sample was transferred to a measuring cylinder. The opening of the graduated cylinder was closed by hand, the graduated cylinder was inverted, the sample was mixed, and the sample was poured into the filter water bottle. The lower lid was opened, and after 5 seconds, the air cock was opened to allow the sample to flow down. The drainage from the side orifice was sampled, and the amount read was taken as the irregular freeness value.

As the paper base material, the paper obtained by papermaking the papermaking raw material may be used as it is. Further, if necessary, the paper after papermaking may be subjected to a parchment treatment to form a paper base material. By applying the parchment treatment, the effect of improving the paper strength and the gas barrier property can be obtained. The parchment treatment is a treatment in which sulfuric acid is used as a cellulose swelling agent to modify it. The parchment treatment can be carried out by a conventional method.

The coating or impregnation of the partition member solution can be carried out by a known method. For example, after the papermaking material is made and dried with a paper machine, the partition member solution is applied in-line to the paper substrate using a coating device (size press, gate roll coater, rod coater, blade coater, etc.) in the paper machine. By drying, a base paper for a partition member can be obtained. Alternatively, after the paper base material is made and dried, a coating device or an impregnating device provided separately from the paper machine is used to apply or impregnate the paper base material with the partition member solution offline, and then the paper base material is dried and the partition member is dried. You can also get a base paper. Alternatively, the paper substrate can be made and dried, then subjected to a parchment treatment, then coated or impregnated with a partition member solution, and then dried to obtain a partition member base paper.

For the application or impregnation of the partition member solution, the content of one or more selected from the group consisting of calcium chloride, magnesium chloride and lithium chloride in the obtained partition member base paper, the density of the partition member base paper and the like are preferable. Various conditions such as the paper base material to be used, the composition of the partition member solution, the coating amount of the partition member solution, and the post-processing are set so as to be within the range.

It should be noted that calcium chloride and the like have high hygroscopicity and usually retain water of crystallization, and it is difficult to calculate the content based on the dry mass. Therefore, when the base paper for a partition member is produced by the above production method, the content of one or more selected from the group consisting of calcium chloride, magnesium chloride and lithium chloride is added to the wet adhesion amount of the partition member solution, such as calcium chloride. It is preferable to calculate as a value obtained by multiplying the concentration of calcium chloride as an anhydride. The concentration of calcium chloride (anhydrous) or the like in the partition member solution can be determined by the EDTA (ethylenediaminetetraacetic acid) titration method.

After the partition member solution is applied and dried, the obtained partition member base paper may be subjected to calendar processing. By applying the calendering process, the density of the base paper for the partition member is improved and the thickness is reduced. By increasing the density of the base paper for the partition member, the gas barrier property is improved, and by reducing the thickness of the base paper for the partition member, the thermal conductivity is improved and the heat exchange efficiency is improved.
The calendar equipment used for the calendar processing is not particularly limited, and for example, known equipment such as a machine calendar, a soft nip calendar, a super calendar, and a gloss calendar can be appropriately used.

After application and drying of the partition member solution, or after application, drying and calendering of the partition member solution, polyvinyl alcohol (PVA) or the like is used on one or both sides of the paper substrate for the purpose of improving gas barrier properties. A coating solution containing a polymer resin may be applied and dried to form a coating layer containing the polymer resin.

[Base paper for spacing members]
The spacing member 3 contains one or more selected from the group consisting of a paper base material containing cellulose fibers as a main component and calcium chloride and magnesium chloride held on the paper base material, and does not contain any other flame retardant.
Therefore, the base paper for the spacing member constituting the spacing member 3 also includes one or more selected from the group consisting of a paper base material containing cellulose fibers as a main component and calcium chloride and magnesium chloride held on the paper base material. It does not contain any other flame retardant.

The paper base material contains cellulose fibers as a main component. "Containing as a main component" means that the ratio to the entire paper substrate is 50% by mass or more. The paper substrate is typically composed of pulp containing cellulose fibers. Examples of the pulp containing the cellulose fibers include those similar to those mentioned in the description of the base paper for partition members. Similarly, it may have undergone a cooking step and / or a bleaching step.
As the pulp, kraft pulp is preferable, and bleached kraft pulp is more preferable, from the viewpoint of base paper strength. Of these, bleached kraft pulp from softwood is preferred.
These pulps may be used alone or in combination of two or more.

The paper substrate may further contain fibers other than the cellulose fibers. Examples of other fibers include synthetic fibers such as rayon fiber, polyethylene fiber, polypropylene fiber and polyester fiber.
The paper base material may contain chemicals such as a sizing agent, a paper strength enhancer, and a colorant. As the internal medicine, known ones can be used.

Since both calcium chloride and magnesium chloride have flame retardancy, holding one or more of them improves the flame retardancy of the spacing member 3.
Further, since calcium chloride and magnesium chloride also function as a hygroscopic agent, by retaining one or more of them, not only the partition member 2 but also the interval member 3 can temporarily absorb water. Therefore, it is possible to suppress dripping that is likely to occur during heat exchange at high humidity.

The distribution state of calcium chloride and magnesium chloride in the base paper for the spacing member is not particularly limited, but at least both surfaces of the paper base material are similar to the base paper for the partition member because the spacing member 3 can easily absorb water efficiently. It is preferable that a part or all of the material is retained.

When a part or all of calcium chloride and magnesium chloride in the base paper for the spacing member is held in a state of being inserted into the gaps between the fibers of the paper base material, the concentration of the paper base material in the thickness direction may be uniform. It may have a concentration gradient such that the concentration decreases from the surface of the paper base material toward the inside. From the viewpoint that the spacing member 3 can easily absorb water, it is preferable to have a concentration gradient such that the concentration decreases from the surface of the paper base material toward the inside.

The retention amount of one or more selected from the group consisting of calcium chloride and magnesium chloride is preferably 3 to 15 g per ^{1 m 2 of base paper for spacing members, and more preferably 3 to 11 g in terms of anhydride.} Further, it is preferably 4 to 25% by mass, more preferably 6 to 16% by mass, in terms of anhydride, with respect to the total mass of the base paper for the interval member.
In particular, when calcium chloride is retained, the content thereof is preferably 4 to 30% by mass, more preferably 6 to 16% by mass, in terms of anhydride, based on the total mass of the base paper for spacing members. When the content of calcium chloride is at least the lower limit of the above range, the flame retardancy and the moisture absorption / desorption performance are more excellent. When the content of calcium chloride is not more than the upper limit of the above range, dripping due to excessive water content at high humidity is unlikely to occur.

The flame retardant that should not be contained in the base paper for the interval member is the same as that listed as the flame retardant that should not be contained in the base paper for the partition member.
By not including these components, the hygroscopic effect of calcium chloride or the like in the partition member 2 is less likely to decrease with time, and efficient heat exchange for a long period of time becomes possible. When these components are contained in the base paper for the interval member, the hygroscopic effect of calcium chloride or the like in the partition member 2 is reduced because the calcium chloride or the like in the partition member 2 reacts with these components contained in the interval member 3 over time. It is thought that this is because it is complexed.

The base paper for the spacing member may hold the humidity control agent in the same manner as the base paper for the partition member. By retaining the temperature control agent, the heat exchange efficiency is improved.
If necessary, the base paper for the spacing member may further contain other additives as long as the effects of the present invention are not impaired. Examples of other additives include fungicides, polymer compounds and the like.
Other additives may be contained in the spacing member base paper in a state of being attached to the surface of the paper base material, or may be contained in the spacing member base paper in a state of being in the gaps between the fibers of the paper base material. Alternatively, it may be contained in the base paper for the spacing member in both a state of being attached to the surface of the paper base material and a state of being in the gap between the fibers of the paper base material.

The base paper for the spacing member preferably has a density of 0.5 to 1.2 g / cm ³ , more preferably 0.7 to 1.1 g / cm ³ , and 0.73 to 0.95 g / cm. It is more preferably ^3.
When the density of the base paper for the interval member is at least the lower limit of the preferable value, the workability is excellent. When the density of the base paper for the spacing member is not more than the upper limit of the preferable value, the water retention is excellent.
The density of the base paper for the spacing member is calculated from the measured values of thickness and basis weight in accordance with JIS P 8118 (1998).

The basis weight of base paper for spacing member is preferably 30 to 200 g / ^{m 2,} and more preferably 50 to 100 g / ^{m 2.} When the basis weight of the base paper for the interval member is equal to or more than the lower limit of the above range, the mechanical strength is excellent. If the basis weight of the base paper for the spacing member is not more than the upper limit of the above range, the economy and workability are excellent.
The basis weight of the base paper for the spacing member is measured in accordance with JIS P P8124 (2011). The basis weight of the paper base material can be obtained in the same manner.

The thickness of the base paper for the spacing member is preferably 0.01 to 0.2 mm, more preferably 0.07 to 0.15 mm. When the thickness of the base paper for the interval member is at least the lower limit of the above range, the mechanical strength is excellent. If the thickness of the base paper for the spacing member is not more than the upper limit of the above range, the economy and workability are excellent.
The thickness of the base paper for the spacing member is measured according to JIS P P8118 (2014). The thickness of the paper base material can be obtained in the same manner.

[Manufacturing method of base paper for spacing members]
The base paper for spacing members is a solution containing one or more selected from the group consisting of calcium chloride and magnesium chloride in a paper base material and containing no other flame retardant (hereinafter, may be referred to as "solution for spacing members"). Can be produced by coating or impregnating.
The solution preferably contains a penetration enhancer that promotes the penetration of calcium chloride or magnesium chloride into the paper substrate. Examples of the permeation accelerator include volatile solvents such as alcohols. Further, if necessary, a humidity control agent, a preservative, a fungicide, a deodorant, a fragrance, other additives and the like may be further contained.

The paper substrate can be produced by making a papermaking material containing cellulose fibers. The paper base material may be single-layer paper or multi-layer paper.
The papermaking raw material may contain other fibers and internal chemicals, if necessary.
Papermaking as a raw material for papermaking can be carried out by using a known method as appropriate.

When the cellulose fibers are pulp, the pulp is beaten and subjected to a papermaking process, depending on the type of paper used. The beating process of pulp can be carried out by a known method in the same manner as described in the method for producing a base paper for a partition member, and for example, a beating device such as a DDR (double disc refiner) is preferably used.

The beating degree of pulp when producing base paper for spacing members is preferably 100 to 700 mL as the freeness (so-called freeness) according to JIS P 811-2 (Canadian standard freeness method), and is 530 to 530. More preferably, it is 700 mL. By setting the freeness within the above range, sufficient paper strength can be obtained as an interval member.
As the paper base material, the paper obtained by papermaking the papermaking raw material may be used as it is. Further, if necessary, calendar processing may be performed.

The coating or impregnation of the spacing member solution can be carried out by a known method in the same manner as described for the method for producing the partition member base paper. It is also possible to obtain a base paper for spacing members by applying a solution for spacing members and drying after papermaking and drying of the paper base material.

For the application or impregnation of the spacing member solution, the content of one or more selected from the group consisting of calcium chloride and magnesium chloride in the obtained spacing member base paper, the density of the spacing member base paper, and the like are within the above-mentioned preferable ranges, respectively. Therefore, various conditions such as the paper base material to be used, the composition of the spacing member solution, the coating amount of the spacing member solution, and the post-processing are set.
When the base paper for interval members is manufactured by the above manufacturing method, the content of one or more selected from the group consisting of calcium chloride and magnesium chloride is determined in the same manner as described in the description of the base paper for partition members. be able to.

After applying and drying the spacing member solution, the obtained spacing member base paper may be subjected to calendar treatment. By applying the calendering process, the density of the base paper for the interval member is improved and the thickness is reduced. By reducing the thickness of the base paper for the spacing member, the effect of reducing the pressure loss can be obtained.
As described in the description of the method for manufacturing the base paper for the partition member, the calendar equipment used for the calendar processing is not particularly limited.

1 ... heat exchanger, 2 ... partition member, 3 ... spacing member, 4 ... first flow path, 5 ... second flow path,
B ... 1st direction, B ... 2nd direction.

Claims (8)

A plurality of partition members and a plurality of interval members that form a flow path between the plurality of partition members and maintain a distance between the partition members are provided.
The plurality of partitioning members include one or more selected from the group consisting of a paper base material containing cellulose fibers as a main component and calcium chloride, magnesium chloride and lithium chloride held on the paper base material, and other flame retardants. Does not include
The plurality of spacing members include one or more selected from the group consisting of a paper base material containing cellulose fibers as a main component and calcium chloride and magnesium chloride held on the paper base material, and do not contain any other flame retardant. A heat exchanger characterized by that. The heat exchanger according to claim 1, wherein the plurality of spacing members hold at least one selected from the group consisting of calcium chloride and magnesium chloride on at least both surfaces of the paper substrate. The heat exchanger according to claim 1 or 2, wherein the plurality of partition members have a density of 0.9 to 1.2 g / cm ^3. The flow path is composed of a first flow path and a second flow path formed in a direction intersecting each other.
The heat exchanger according to any one of claims 1 to 3, wherein the first flow path and the second flow path are adjacent to each other with the partition member interposed therebetween. A spacing member used as the spacing member in a heat exchanger including a plurality of partitioning members and a plurality of spacing members that form a flow path between the plurality of partitioning members and maintain a spacing between the partitioning members. It is a base paper for use
The interval is characterized by containing one or more selected from the group consisting of a paper base material containing a cellulose fiber as a main component and calcium chloride and magnesium chloride held on the paper base material, and not containing any other flame retardant. Base paper for members. The base paper for a spacing member according to claim 5, wherein at least one or more selected from the group consisting of calcium chloride and magnesium chloride is held on at least both surfaces of the paper base material. A spacing member used as the spacing member in a heat exchanger including a plurality of partitioning members and a plurality of spacing members that form a flow path between the plurality of partitioning members and maintain a spacing between the partitioning members. It is a manufacturing method of base paper for use.
A paper substrate containing cellulose fibers as a main component is coated or impregnated with a solution containing one or more selected from the group consisting of calcium chloride and magnesium chloride and containing no other flame retardant. A method for manufacturing base paper for members. The spacing member according to claim 7, wherein the solution is applied or impregnated so that the holding amount of one or more selected from the group consisting of calcium chloride and magnesium chloride is 3 to ^{15 g per 1 m 2 of the base paper for the spacing member.} Manufacturing method of base paper.

Images