JP5649024B2 - Dehumidifying filter and desiccant air conditioner using the same - Google Patents

Description

The present invention, dehumidification filters relates to the desiccant air-conditioning equipment having a desiccant rotor using the same. More specifically, the present invention relates to a dehumidifying filter that can be suitably used as a desiccant rotor provided in a desiccant air conditioner. Further, the present invention relates to a dehumidifying filter that can reproduce the dehumidifying ability even at room temperature when a desiccant rotor is used, and can also function as a total heat exchanger in which dehumidification and heat exchange are performed simultaneously depending on conditions.

  In recent years, a latent heat / sensible heat separation type desiccant air conditioner has been proposed as a new technology to replace a cooling / dehumidification type air conditioner using a cooling coil. The desiccant air conditioner uses a desiccant rotor for efficient dehumidification and regeneration, and the desiccant rotor uses a dehumidifying material having excellent dehumidifying ability such as silica gel, zeolite, and activated carbon. In recent years, siliceous shale, which is an inexpensive material that exhibits high moisture absorption and desorption properties, has attracted attention as one of the dehumidifying materials, and is widely used as a humidity control material in building materials (for example, Patent Document 1 and Patent Document 2). And unlike the cooling / dehumidification type air conditioner, the desiccant air conditioner does not need to be supercooled or reheated, saves energy, and suppresses the emission of CFCs and greenhouse gases. Therefore, further spread is expected in the future.

  On the other hand, conventionally, the desiccant air conditioner has only a large size, and many of them are limited to business use, and are hardly used for home use. One reason for this is that the conventional desiccant air conditioner requires a high-temperature heat source of 80 ° C. or higher in order to regenerate the desiccant rotor in which moisture in the air is dehumidified. That is, in order to regenerate with a high-temperature heat source of 80 ° C. or higher, a heater, a steam coil, a hot water coil, and the like must be incorporated in the apparatus, and thus the apparatus must be made large.

Japanese Patent No. 2651593 Japanese Patent No. 2964393

  Therefore, the object of the present invention is not only to have an excellent dehumidifying ability, but also to a desiccant rotor that has the ability to be easily and reliably regenerated at a lower temperature, ideally at room temperature. An object of the present invention is to provide a dehumidifying filter that is extremely suitable in terms of energy saving and apparatus miniaturization.

The above object is achieved by the present invention described below. That is, the present invention is a dehumidifying filter, wherein a dehumidifying material comprising a siliceous shale having a plurality of pores having an average pore diameter of 3 to 18 nm and a specific surface area of 80 m ² / g or more is formed on a substrate. , will be deposited or be contained, wherein the substrate, the paper substrate, a nonwoven substrate or ceramic substrate, the dehumidifying material, within at least pores of the siliceous shale, sodium chloride 10-150 mg / It is a dehumidifying filter characterized by being adhered within the range of g and having an excellent dehumidifying ability from a middle humidity region to a high humidity region .

Another embodiment of the present invention is a desiccant air conditioner in which the dehumidifying filter is applied to a desiccant rotor .

  According to the present invention, there is provided a dehumidifying filter that can be applied to a desiccant rotor that has an excellent dehumidifying ability, can exhibit an excellent regeneration ability at a low temperature of about 40 ° C., and can be used repeatedly over a long period of time. Is done. In addition, according to the present invention, depending on conditions such as the number of rotations of the rotor, regeneration is possible even at room temperature, and a surprising effect that the dehumidification performance is restored is equivalent to or more than that at 40 ° C., Furthermore, 30 ° C. air treated by normal temperature regeneration at 26 ° C. is lower than 30 ° C., and by using this, the function as a total heat exchanger in which dehumidification and heat exchange are performed simultaneously can be expressed. A possible dehumidification filter is provided. In addition, according to the present invention, it is possible to omit a heater that has been necessary for regeneration in the past, so that it is possible to reduce the size of a desiccant air conditioner or the like to which a desiccant rotor is applied, and at the same time save energy. Can be achieved and a significant cost reduction is expected.

The measurement result which shows the dehumidification material of the dehumidification material used by this invention, and the repeated dehumidification and reproduction | regeneration ability of A type silica gel. The measurement result which shows the repeated dehumidification and regeneration capability of the dehumidification filter of this invention. It is the schematic which shows an example of the dehumidification filter of this invention. It is the schematic which shows the state which inserted | pinched the dehumidification filter of FIG. 3 into the box to which the motor was attached, and was made into the dehumidification rotor. It is the schematic of the ventilation box used for evaluation of the dehumidification rotor of FIG. It is the schematic which shows an example of the dehumidification filter of this invention. It is a graph which shows the relationship between the regeneration air temperature and the dehumidification amount in that case at the time of using the dehumidification filter of this invention for a rotor. It is a graph which shows the relationship between the rotation speed of a rotor, and the dehumidification amount in that case at the time of using the dehumidification filter of this invention for a rotor. It is a graph which shows the relationship between the rotation speed of a rotor, and the temperature of the air (SA) supplied indoors when the dehumidification filter of this invention is used for a rotor.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. As described above, in order to promote further popularization of the desiccant air conditioner, it is required to make the device smaller and more energy-saving so that it can be used for home use. In order to reduce the size of the apparatus, it is effective to omit or downsize equipment such as a heater, a steam coil, and a hot water coil. For this purpose, the desiccant rotor is ideally at room temperature, at least at room temperature. It is required to be able to reproduce quickly at a slightly higher and lower temperature. In developing a small desiccant system for home use, the present inventors considered the following four points as main issues, and selected a material suitable for such a desiccant system and matched the material to these purposes. A detailed study was conducted focusing on the development of the method to make the state. The present invention has been achieved as a result of such studies.
(1) Development of materials that can absorb a large amount of moisture in the partial pressure difference of water vapor from 3 kPa to 1.5 kPa (2) Development of materials that can be adsorbed only by physical adsorption that can be regenerated at low temperatures (3) Characteristics even after repeated low-temperature regeneration Of highly durable materials that do not change (4) Development of systems that effectively utilize unused low-temperature exhaust heat such as air-conditioner exhaust heat as regeneration air

The present inventors first examined a desiccant rotor, that is, a dehumidifying material that greatly contributes to dehumidification / regeneration of the dehumidifying filter constituting the desiccant rotor. As a result, siliceous shale having a large number of pores having an average pore diameter of 3 to 12 nm and a specific surface area of 80 m ² / g or more, represented by the Wakkanai siliceous shale, has a high dehumidifying ability, It was found that a certain degree of regeneration ability was exhibited at ℃. Specifically, when siliceous shale is allowed to stand for 24 hours in an environment with a temperature of 40 ° C. and a relative humidity of 30%, and then left for 2 hours in an environment with a temperature of 30 ° C. and a relative humidity of 75%, 65 mg / There is a mass increase (dehumidification capacity) of about g, and a mass decrease (regeneration capacity) of about 65 mg / g when left for 2 hours in an environment where the temperature is 40 ° C. and the relative humidity is 30%. Okay (see Figure 1). From these facts, the present inventors have found that a desiccant rotor that can be regenerated at a low temperature can be produced by using a siliceous shale having the above-mentioned characteristics as a dehumidifying material to produce a dehumidifying filter. Obtained.

  However, it has been found that the siliceous shale having the above-mentioned characteristics tends to have a lower dehumidifying capacity than A-type silica gel, which has been widely used as a dehumidifying material for desiccant rotors (dehumidifying filters). On the other hand, although A-type silica gel has excellent dehumidifying ability, it needs to be regenerated at 80 ° C. or higher, and there is a problem that the material cost is high, so it is not suitable for application to a small desiccant system for home use. It is. Thus, as a result of further studies, the present inventors have maintained the effect of regenerating at a low temperature when a deliquescent substance is appropriately attached or contained in at least the pores of the siliceous shale having the above-described characteristics. We found a surprising phenomenon that the dehumidifying ability of siliceous shale is greatly improved. This means that it becomes more useful as a desiccant rotor capable of low-temperature regeneration by forming a dehumidifying filter using siliceous shale to which a deliquescent substance is appropriately attached as a dehumidifying material. According to the study by the present inventors, in particular, in the case of using a sodium chloride alone or one containing sodium chloride among the deliquescent substances, the dehumidifying filter is in the same operating state of the desiccant rotor as in the conventional case. It has been found that the dehumidifying ability can be drastically improved from the middle humidity range to the high humidity range particularly required for the desiccant rotor while maintaining the effect of regeneration at a low temperature of about 40 ° C. As a result of the above studies, when forming a desiccant rotor, the present inventors have used a dehumidifying filter in which a dehumidifying material in which a deliquescent material such as sodium chloride is attached or contained in siliceous shale having the specific characteristics described above is used. It was concluded that it would be useful to use as a material.

As a result of further investigation on the possibility of regeneration at a lower temperature, the present inventors usually conducted a trial of about 0.5 to 0.7 rpm (30 to 40 rpm) in the case of a conventional desiccant rotor. It was found that even if the speed was increased, the engine was operated at a low speed of 1 rpm (60 rph), whereas when the number of rotations was increased, regeneration at a lower temperature was possible. A dehumidification filter comprising a Wakkanai-layer siliceous shale-containing paper having a corrugated structure wound in a layer using a siliceous shale having the above-mentioned properties with sodium chloride attached to a base synthetic paper When the rotor was formed using and studied, the following was found. First, when the temperature of the regenerative air is changed stepwise from 26 ° C. to 50 ° C., and the regenerative air is sent at a flow rate of 150 m ³ / h with a relative humidity of 60% constant, However, when the rotor is rotated at a remarkably fast 7.5 rpm (450 rph), as shown in FIG. 7, even at a room temperature of about 26 ° C., it can be reproduced to the same level or higher than at 40 ° C. It was. Second, as shown in FIG. 8, in this case, the regenerative performance is improved as the number of rotations of the rotor is increased, and this tendency is higher when the temperature is higher than when the temperature is higher. I found very interesting findings that the effect is higher. Third, as shown in FIG. 9, when the outside air temperature is 30 ° C. and the relative humidity is 75% and the regeneration air is constant at 26 ° C. and the relative humidity is 60%, the rotational speed of the rotor increases. It has been found that the temperature of the air supplied to the room decreases. For example, as a result of performing the test under the above-mentioned conditions at a rotation speed of 22 rpm, humid outside air having a temperature of 30 ° C. and a relative humidity of 75% is dehumidified, and further heat exchange is performed with regenerated air having a temperature of 26 ° C. and a humidity of 60%. As a result, the air supplied to the room had a temperature of 26.82 ° C. and a humidity of 63.47%. This means that if operating conditions such as the number of rotations of the rotor are appropriately determined, it is possible to construct a very useful desiccant system that has high dehumidifying performance and at the same time functions as a total heat exchanger. Yes. According to the study by the present inventors, the rotational speed of the rotor is more than 1 rpm and not more than 30 rpm, more preferably not less than 2 rpm and not more than 25 rpm, and further preferably not less than 5 rpm and not more than 22 rpm.

  The present inventors have also studied the further modification of siliceous shale having the above-described characteristics used as a dehumidifying material. As a result, for example, it was found that when the siliceous shale is subjected to alkali etching treatment, the moisture absorption performance is improved as compared with the siliceous shale rough. That is, in this case, it has been found that the dehumidifying ability of the dehumidifying filter is improved and it can be used more suitably as a desiccant rotor. In addition, when the alkali etching treatment is performed, the pores of the siliceous shale may spread, but it is preferable to adjust the average pore diameter to be 18 nm or less.

The dehumidifying filter of the present invention found from the above background is basically a siliceous material having a large number of pores having an average pore diameter of 3 to 18 nm and a specific surface area of 80 m ² / g or more on a substrate. A dehumidifying material made of shale is attached or contained. And this dehumidification material is adjusted so that it may have a characteristic suitable as a dehumidification material used for a desiccant rotor. Specifically, after standing for 24 hours in an environment with a temperature of 40 ° C. and a relative humidity of 30%, and then standing for 2 hours in an environment with a temperature of 30 ° C. and a relative humidity of 75%, the mass increases by 60 mg / g or more. In addition, after that, when left in an environment of a temperature of 40 ° C. and a relative humidity of 30% for 2 hours, there is a mass loss of 60 mg / g or more, and the mass increase amount described above and the mass decrease amount described above The difference is adjusted so as to be 20 mg / g or less (see FIG. 1). In the present invention, a deliquescent substance (preferably containing sodium chloride) is contained in at least the pores of the siliceous shale in order to allow higher dehumidification performance and regeneration at a lower temperature as described above. To be attached or contained. In addition, it is also a preferable embodiment that the siliceous shale has been subjected to alkali etching treatment.

  The dehumidifying filter having such a configuration can exhibit an excellent regenerating ability at 40 ° C. under the same operating conditions as a conventional desiccant rotor while having an excellent dehumidifying ability. As described above, when the number of rotations is increased as compared with the conventional one, an unprecedented remarkable effect that high reproducibility is exhibited at room temperature can be obtained. Furthermore, as described above, depending on the operating conditions, it can function as a total heat exchanger, so that it is possible to construct a desiccant system that is small and achieves energy saving, and is particularly useful for home use. Moreover, when the dehumidification filter of this invention was used repeatedly, it confirmed that the dehumidification capability which a filter has continued showing effectively. Therefore, the dehumidification filter of this invention can be used suitably as a desiccant rotor also in terms of durability, and it turned out that it is suitable. Hereinafter, the present invention will be described in more detail.

  The configuration of allowing the dehumidifying material defined in the present invention to be selected, which is allowed to stand for 24 hours in an environment of a temperature of 40 ° C. and a relative humidity of 30%, serves as a reference for measuring the dehumidifying ability. The amount of mass increase is the difference from this reference value.

  The dehumidifying treatment in the desiccant rotor is assumed under the environment of a temperature of 30 ° C. and a relative humidity of 75%, which are requirements for selecting the dehumidifying material defined in the present invention. In the present invention, the dehumidifying material is allowed to stand for 24 hours in the above-mentioned standard environment, and then left to stand for 2 hours in an environment assuming this dehumidifying treatment, resulting in a mass increase of 60 mg / g or more. It will occur. In this case, the amount of increase in mass is preferably 80 mg / g or more, and more preferably 100 mg / g or more. In the present invention, since the dehumidifying material is adjusted so that the mass increase amount is 60 mg / g or more as described above, the dehumidifying filter can exhibit an excellent dehumidifying ability and is preferably used as a desiccant rotor. obtain. In particular, when using siliceous shale with deliquescent material attached, it is possible to obtain a much higher dehumidifying capacity than when using siliceous shale rough. In this case, by increasing the dehumidifying capacity of the desiccant rotor, it is possible to suppress the increase in size and to reduce the size of the apparatus.

  On the other hand, in an environment of a temperature of 40 ° C. and a relative humidity of 30%, a regeneration process in a desiccant rotor is assumed. And in this invention, a dehumidification material produces the mass reduction | decrease of 60 mg / g or more when it leaves still for 2 hours in the environment which assumed this reproduction | regeneration process after the state of above-mentioned mass increase. In this case, the mass reduction amount is preferably 80 mg / g or more, and more preferably 100 mg / g or more. In this invention, since the dehumidification material is adjusted so that it may become a mass loss amount of 60 mg / g or more, a dehumidification filter can exhibit the outstanding regeneration capability and can be used suitably as a desiccant rotor. That is, when the regenerated desiccant rotor is used again for the dehumidification treatment, it is possible to make a sufficient amount of dehumidification possible.

  It should be noted that, in the environment assuming the above-mentioned dehumidification or regeneration, the condition is to stand for 2 hours, but this is only a guideline for measuring the dehumidification / regeneration capability, meaning that it takes 2 hours for dehumidification or regeneration. It is not. Rather, as shown in FIG. 1, the dehumidifying material formed by attaching a deliquescent substance to siliceous shale has a proportionally increased or decreased mass during dehumidification or regeneration. Reproduction is considered to occur quickly. That is, when the dehumidifying filter of the present invention using such a dehumidifying material is used as a desiccant rotor, it can dehumidify and regenerate quickly and at a high level. This also makes it possible to increase the number of revolutions, to make a desiccant rotor with a high dehumidifying capacity, and to build an extremely energy saving system.

  In the present invention, the dehumidifying material is adjusted so that the difference between the mass increase amount and the mass decrease amount in the case described above is 20 mg / g or less. Preferably, it is 15 mg / g or less, More preferably, it is 10 mg / g or less. In this invention, since it adjusts so that it may be 20 mg / g or less, a dehumidification filter can suppress moisture accumulation to the minimum and can endure repeated use. In particular, when adjusted to 10 mg / g or less, the initial dehumidifying ability can be maintained over a long period of time, which is optimal for desiccant rotor applications that require repeated use.

In the present invention, a siliceous shale rough having many fine pores having an average pore diameter of 3 to 12 nm and a specific surface area of 80 m ² / g or more can be used as the siliceous shale. In addition, a siliceous shale rough ore modified by expanding pores (average pore diameter of 18 nm or less) can also be used. That is, the siliceous shale used in the present invention has many pores having an average pore diameter of 3 to 18 nm and a specific surface area of 80 m ² / g or more. As described above, the siliceous shale rough having the above characteristics also has excellent moisture absorption and desorption performance in the rough, and examples of the siliceous shale rough having such characteristics include, for example, Hokkaido Tenpoku The so-called Wakkanai-layered siliceous shale produced in the region can be mentioned. The Wakkanai siliceous shale has the above-mentioned characteristics, and has a sharp pore size distribution with a pore volume in the range of 0.1 to 0.4 ml / g and a maximum moisture absorption of 15% by mass or more. It is a natural porous body. According to the study by the present inventors, it is particularly preferable in the present invention to use siliceous shale having a specific surface area of 100 m ² / g or more.

In the present invention, the pore volume was measured by the BJH (Barrett Joyner Halenda) method. The specific surface area was measured by the BET (Brunauer Emmet Teller) method. Further, the average pore diameter was calculated from the following formula based on the pore volume and specific surface area measured by the above method, assuming that the pore was a cylindrical body. The maximum moisture absorption rate is 48 by placing the measurement object in an oven at 150 ° C. and holding it for 72 hours and then measuring the absolute dry mass of the object, and then placing it in a constant temperature and humidity chamber at 25 ° C. and a relative humidity of 95%. It is obtained by the mass increase rate with respect to the mass of the object to be measured again after holding for a time. Changes in the amount of moisture adsorbed and the amount of moisture released according to the relative humidity can be continuously measured with a water vapor adsorption amount measuring apparatus.
(Formula) Average pore diameter = 4 × pore volume (ml / g) ÷ specific surface area (m ² / g)

In the present invention, as described above, in order to obtain a dehumidifying material having higher dehumidifying ability and regenerating ability, at least a large number of pores having an average pore diameter of 3 to 18 nm and a specific surface area of 80 m ² / g or more. It is preferable to attach a deliquescent substance to at least the pores of the siliceous shale having pores. Examples of the deliquescent material include lithium chloride, sodium chloride, magnesium chloride, calcium chloride and the like. Preferred are lithium chloride, sodium chloride, and calcium chloride, and more preferred is sodium chloride. When sodium chloride is used, the amount of moisture absorption (dehumidification capacity) increases dramatically from the middle humidity range (relative humidity 53 to 75%) to the high humidity range (relative humidity 75 to 93%), while being about 40 ° C. Regeneration ability to release almost all of the moisture absorbed at low temperature will be exhibited. These deliquescent substances may be used in combination.

  In the present invention, it is preferable to appropriately adjust the amount of the deliquescent substance attached to the siliceous shale so as to have the dehumidifying ability and the regenerating ability as described above. It can be in the range of ˜150 mg / g. Moreover, when using lithium chloride, magnesium chloride, or calcium chloride, it can be in the range of 10-250 mg / g. If it falls below these ranges, the moisture absorption / release performance with the siliceous shale rough ore may not change so much, and the dehumidification / regeneration ability improvement effect may be small. On the other hand, when it exceeds these ranges, deliquescent substances may be scattered or spilled. Considering these viewpoints more preferably, it is in the range of 15 to 60 mg / g when sodium chloride is used, in the range of 20 to 50 mg / g when lithium chloride is used, and when calcium chloride is used. Is in the range of 20-50 mg / g. However, the amount of these deposits is not limited to the above-mentioned numerical values, so as to have the dehumidifying ability and regeneration ability as described above, characteristics of siliceous shale, modified state, types of deliquescent substances, combinations, etc. Is determined as appropriate.

  In the present invention, the method for attaching the deliquescent substance to the surface and pores of the siliceous shale is not particularly limited.For example, after the siliceous shale is immersed in an aqueous solution of the deliquescent substance, The method of drying is mentioned.

  In addition, when the deliquescent material is attached to the siliceous shale as described above, the concentration of the deliquescent material aqueous solution is preferably adjusted so as to have the dehumidifying ability and the regenerating ability as described above. For example, the concentration of the deliquescent substance in the aqueous solution can be adjusted within a range of 1 to 25% by mass. When it is less than this range, the moisture absorption / release performance with the siliceous shale rough stone does not change so much, and the dehumidification / regeneration ability improvement effect may be small. On the other hand, if it exceeds this range, deliquescent substances may be scattered or spilled. From these viewpoints, the concentration of the sodium chloride aqueous solution is particularly preferably adjusted within the range of 1 to 15% by mass, and more preferably 1 to 8% by mass. Moreover, it is preferable to adjust the density | concentration of lithium chloride aqueous solution in the range of 3-7 mass%, and it is preferable to adjust the density | concentration of calcium chloride aqueous solution in the range of 3-7 mass%. However, these concentrations are not limited to the above values, and the siliceous shale properties, modified state, types of deliquescent substances, combinations, etc. are selected so as to have the dehumidification ability and regeneration ability as described above. It is determined with appropriate consideration.

  Further, evacuation may be performed in a state where the siliceous shale is immersed in an aqueous solution of a deliquescent material. In this case, the air remaining inside the pores of the siliceous shale is drawn out, and the aqueous solution can be made to penetrate to the deep part of the pores. That is, the contact efficiency between the inner wall of the pores of the siliceous shale and the aqueous solution can be increased, and the deliquescent substance in the aqueous solution can be more efficiently and more stably attached. The vacuuming conditions are not particularly limited, but for example, it is preferably 30 to 200 minutes at room temperature.

  In addition to evacuation, the deliquescent substance described above may be adhered by allowing the siliceous shale to stand still in a state of being immersed in the aqueous solution. The conditions for standing still are not particularly limited, but are preferably 700 to 2,000 minutes at room temperature, for example.

  The drying process may be air drying, hot air drying, forced drying by an oven, or vacuum drying. In this invention, it is preferable to dry completely, for example, it is preferable to dry-process at 40-400 degreeC. In addition, the siliceous shale is not particularly limited with respect to the upper limit of the drying temperature because the voids hardly change up to 900 ° C. What is necessary is just to set it as efficient conditions according to the apparatus used for a drying process.

  In addition, the deliquescent material adheres to siliceous shale by using an aqueous solution of deliquescent material instead of water when wet pulverizing siliceous shale with a ball mill, etc. The method of attaching a substance is mentioned. In this method, the adhesion of sodium chloride and the fine pulverization of the siliceous shale can be performed simultaneously, so that it is very efficient and can be performed at low cost. The pulverization conditions are not particularly limited, and a pulverization time suitable for obtaining a powder having a desired particle diameter can be selected. For example, when the particle size is 20 μm or less, the deliquescent substance can be adhered by pulverizing under the pulverization conditions for obtaining the required particle size, such as by pulverizing for 12 hours or more. The drying process in this method can be performed by the same method as described above.

  Moreover, as a siliceous shale used for this invention, the siliceous shale raw stone which has the above-mentioned characteristic may be used as it is, and what changed the state of the pore may be used. Examples of the method for modifying the state of the pores of the siliceous shale include alkali etching treatment. When the etching treatment is performed, the specific surface area tends to be slightly lower than that of the siliceous shale rough, but the pore volume can be increased and the moisture absorption / release performance can also be improved. That is, the dehumidifying / regenerating ability of the dehumidifying filter can be improved. In the present invention, it is preferable that the pore volume of the siliceous shale is adjusted to 0.40 ml / g or more by a method such as etching treatment. On the other hand, if the pore volume is too large, the excellent moisture absorption / release performance of the siliceous shale may be impaired. Therefore, the pore volume is preferably 0.65 ml / g or less. A particularly preferable pore volume is in the range of 0.45 to 0.50 ml / g, which has a high effect of improving moisture absorption / release performance. In addition, when alkali etching is performed, the pores of the siliceous shale rough may also expand. In this case, the average pore diameter is preferably adjusted to 18 nm or less so that the siliceous shale can maintain a state having many fine pores. That is, the average pore diameter of the siliceous shale (raw stone, modified product) used in the present invention is in the range of 3 to 18 nm.

  The alkali etching treatment can be performed by immersing the siliceous shale in an aqueous solution of an alkaline compound such as sodium hydroxide or potassium hydroxide. In particular, it is preferable to use an aqueous sodium hydroxide solution. The density | concentration of the aqueous solution of an alkaline compound can be in the range of 0.5-3.0 mol / l, for example. Further, evacuation may be performed in a state where the siliceous shale is immersed in an aqueous solution of an alkaline compound, or the siliceous shale may be left still. Preferably, the evacuation is more effective in improving the moisture absorption / release performance of the siliceous shale. The vacuuming condition is preferably 45 to 300 minutes at room temperature, for example, and the standing condition is preferably 1,000 to 2,500 minutes at room temperature. After performing the alkali etching process, it is preferable to perform a drying process by the above-described method or the like. The alkali etching treatment may be performed simultaneously with the adhesion of the deliquescent material to the siliceous shale. Specifically, using an aqueous solution containing a deliquescent substance and an alkaline compound, the deliquescent substance adhering to the siliceous shale and alkaline etching treatment are performed simultaneously by immersing in siliceous shale and drying. obtain.

  In the present invention, for the purpose of imparting other functions, the dehumidifying material may have a substance other than the aforementioned substances attached to the surface or pores of the siliceous shale. Moreover, you may mix | blend a binder component with above described aqueous solution.

  The dehumidifying filter of the present invention can be obtained by adhering or containing a dehumidifying material having the above configuration to a substrate using a conventionally known method. That is, the dehumidifying filter of the present invention can have the same configuration as the dehumidifying filter used as a conventionally known desiccant rotor except that the dehumidifying material described above is used. For example, the substrate constituting the dehumidifying filter is not particularly limited in its material or structure, and any substrate can be used as long as it is a substrate for a dehumidifying filter conventionally used as a desiccant rotor. More specifically, examples of the material for the base material include paper, nonwoven fabric, and ceramics. Further, examples of the structure of the base material include a corrugated structure and a honeycomb structure. Further, the structural design such as the number of cells in the corrugated structure or the honeycomb structure can be made the same as the conventional one. Moreover, in the case of the nonwoven fabric base material which consists of a nonwoven fabric, it can be set as the structure formed by laminating | stacking a some nonwoven fabric. According to the study by the present inventors, in particular, paper, particularly synthetic paper, is used as a material for the base material, and siliceous shale is obtained by including siliceous shale powder in the raw slurry when preparing synthetic paper. It is particularly preferable to prepare a paper containing the paper, and to further have a corrugated structure in which the paper is finely waved about several millimeters in height, and a dehumidifying filter having the following shape using the paper. . That is, a long paper having the above corrugated structure is densely wound to form a cylindrical dehumidification filter, and a deliquescent material adhered thereto has a high dehumidification function, is lightweight and has excellent durability, When applied to a desiccant rotor, it is rapidly regenerated at a temperature as low as 40 ° C. and further at room temperature depending on operating conditions.

In addition, when the dehumidifying filter of the present invention is obtained by attaching a dehumidifying material to a base material, the dehumidifying material is contained in a binder such as an emulsion, and then this is used by impregnation coating, spray coating, roll coating, or the like. Can be used. As a binder in this case, it is preferable to use a binder having air permeability so that the dehumidifying / regenerating ability of the dehumidifying material is not hindered, such as an acrylic resin added with an additive such as water glass, or an air-permeable binder. It is preferable to use what is called. Examples of the air-permeable binder include at least 15 to 70% by mass of a dehumidifying material, a resin emulsion having an amount of resin of 30 to 70% by mass, and a moisture permeability of an amount of solid content of 5 to 40% by mass. A coating agent (containing the dehumidifying material described above) for forming a porous continuous film in which the glass transition temperature of the resin constituting the resin emulsion is in the range of −50 to 30 ° C. Can be used (see Japanese Patent Application Laid-Open No. 2008-138167). In addition, a film-forming aqueous emulsion composed of synthetic resin particles having a particle size of 0.03 to 10 μm and water and colloidal silica are the main components. An emulsion obtained by emulsion polymerization of a saturated monomer and acrylic silane or vinyl silane, wherein the colloidal silica has a particle size of 1/3 or less of the synthetic resin particles, and further, the blending amount of the colloidal silica However, it is also possible to use a breathable binder having a mass that is 0.5 to 30 times the mass for completely covering the synthetic resin particles (see JP-A-3-106948). The greater the content of the dehumidifying material in the binder, the better the moisture absorbing / releasing performance (dehumidification / regeneration capability), but it is particularly preferably in the range of 30 to 70% by mass. When the amount is less than 30% by mass, the dehumidifying ability may be low. When the amount exceeds 70% by mass, the binder ability may be low, and a problem may occur in the fixing force to the substrate. Moreover, it is preferable to make the adhesion amount of the dehumidification material with respect to a base material into the range of 10-70 g / m < ² >, for example. However, the adhesion amount of the dehumidifying material is not particularly limited, and may be appropriately adjusted according to the type of base material and the required performance.

  In addition, when the dehumidifying filter of the present invention is obtained by including a dehumidifying material in the base material, for example, when forming the base material, a method of obtaining the dehumidifying material together with the material constituting the base material is used. it can. For example, in the case of a paper base made of paper, a paper base containing a dehumidifying material can be obtained by blending a paper-making slurry with a dehumidifying material and making the paper. Moreover, the content of the dehumidifying material with respect to the dehumidifying filter is not particularly limited, but is preferably in the range of 20 to 90% by mass with respect to the total mass of the dehumidifying filter. Moreover, when using a paper base material and a nonwoven fabric base material, it is more preferable to set it in the range of 20-70 mass% with respect to the dehumidification filter total mass. If it is less than 20% by mass, the dehumidifying ability may be low, and if it exceeds 90% by mass, the strength of the substrate may be weak and filter forming may be difficult. Especially preferably, it exists in the range of 30-60 mass%. Moreover, when using a ceramic base material, it is more preferable to make it into the range of about 80 mass% from the balance of dehumidification and reproduction | regeneration performance, and intensity | strength, specifically, 75-85 mass%.

  The dehumidifying filter of the present invention can be used as a desiccant rotor by forming it in a predetermined shape as described above. Although there is no restriction | limiting in particular in the shape of a desiccant rotor, For example, what was formed in the disk shape is mentioned. The desiccant rotor formed using the dehumidifying filter of the present invention is excellent in dehumidifying ability and exhibits excellent regenerating ability at 40 ° C. and further at room temperature. Moreover, since it is possible to maintain the initial state of the dehumidifying capacity over a long period of time, it is excellent in repeated durability. In other words, the dehumidifying filter of the present invention is extremely effective in reducing the size and energy saving of the desiccant air conditioner, and can promote the popularization for household use.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further more concretely, unless the summary is exceeded, this invention is not limited by the following Example. In this example, the value of the specific surface area was measured by the BET method, and the value of the pore volume was measured by the BJH method. The average pore diameter is calculated from the specific surface area and the pore volume using the above formula.

<Production of dehumidifying material>
(Siliceous shale rough)
The Wakkanai siliceous shale produced from Tenboku, Hokkaido was crushed with a hammer crusher and sieved to adjust the particle size to 1 to 2 mm. The obtained Wakkanai layer siliceous shale (raw stone) particles were designated as dehumidifying material 1. The dehumidifying material 1 had a specific surface area of 149 m ² / g, an average pore diameter of 10.2 nm, and a pore volume of 0.38 ml / g.

(Adhesion of deliquescent substances)
[Sodium chloride]
After impregnating the particles of the Wakkanai layer siliceous shale (raw stone) obtained above with a 5% by mass sodium chloride aqueous solution, vacuuming (normal temperature) was performed in a desiccator for 1 hour. Thereafter, the dehumidified material 2 was further obtained by suction filtration and drying in an oven at 150 ° C. to attach sodium chloride to the surface and pores of the Wakkanai layer siliceous shale. In addition, it was 37 mg / g when the adhesion amount of sodium chloride in the dehumidification material 2 was measured by the mass change of the siliceous shale (absolutely dry) before and after making sodium chloride adhere.

  In the same manner as above, except that 3% by mass sodium chloride aqueous solution or 10% by mass sodium chloride aqueous solution is used instead of 5% by mass sodium chloride aqueous solution, sodium chloride is adhered to the raw siliceous shale. The dehumidifying materials 3 and 4 were obtained. In addition, it was 24 mg / g and 70 mg / g, when the adhesion amount of sodium chloride in the dehumidification materials 3 and 4 was measured by the mass change of the siliceous shale (absolute dry) before and after making sodium chloride adhere.

[Lithium chloride]
A dehumidifying material 5 obtained by attaching lithium chloride to a siliceous shale rough was obtained in the same manner as described above except that a 4% by mass lithium chloride aqueous solution was used instead of the 5% by mass sodium chloride aqueous solution. In addition, it was 27 mg / g when the adhesion amount of lithium chloride in the dehumidification material 5 was measured by the mass change of the siliceous shale (absolutely dry) before and after making lithium chloride adhere.

[Calcium chloride]
A dehumidifying material 6 was obtained by adhering calcium chloride to a raw siliceous shale in the same manner as described above except that a 5% by mass calcium chloride aqueous solution was used instead of the 5% by mass sodium chloride aqueous solution. In addition, it was 37 mg / g when the adhesion amount of the calcium chloride in the dehumidification material 6 was measured by the mass change of the siliceous shale (absolute dry) before and after making calcium chloride adhere.

<Dehumidification / regeneration capability test>
The dehumidifying materials 1 and 2 and A-type silica gel were allowed to stand for 24 hours in an environment of a temperature of 40 ° C. and a relative humidity of 30%, and then the masses were measured to obtain respective reference values. Next, these were allowed to stand for 2 hours in an environment with a temperature of 30 ° C. and a relative humidity of 75%, and then left for 2 hours in an environment with a temperature of 40 ° C. and a relative humidity of 30%. The mass was measured over time by repeating 5 cycles. The mass difference with respect to the reference value of the obtained measured value is defined as a mass change amount and is shown in FIG. In the first cycle, the mass difference A from the reference value immediately after standing for 2 hours in an environment at a temperature of 30 ° C. and a relative humidity of 75%, and for 2 hours in an environment of a temperature of 40 ° C. and a relative humidity of 30% The mass difference B from the reference value immediately after placement is shown in Table 1 together with AB. In addition, about the dehumidification materials 1 and 2, even after repeating 5 cycles, it repeated until 20 cycles and measured the mass, but there was almost no mass difference with a reference value.

  Also for the dehumidifying materials 3 to 6, the mass difference A and the mass difference B were measured by the same method as described above, and the results are shown in Table 1 together with AB.

  From the above evaluation results, the dehumidifying filter using siliceous shale as a dehumidifying material can be regenerated at 40 ° C. unlike a dehumidifying filter using A-type silica gel as a dehumidifying material, and can be excellent in repeated durability. confirmed. In particular, a dehumidifying filter using siliceous shale to which deliquescent material (and sodium chloride) is attached as a dehumidifying material exhibits a particularly excellent dehumidifying ability while maintaining its regeneration ability at 40 ° C. confirmed.

<Prototype and evaluation of dehumidifying filter>
From the above examination results, we made a prototype dehumidification filter using siliceous shale with attached or contained chloride as a deliquescent material as a dehumidification material as follows, and about the moisture absorption and desorption performance of the obtained dehumidification filter Was evaluated. Hereinafter, these will be described.

(Prototype of dehumidification filter made of Wakkanai siliceous shale-containing paper)
The Wakkanai siliceous shale was wet crushed by a ball mill, and the pulverization time was adjusted to adjust the average particle size to 20 μm. Using an aqueous slurry containing 45 parts by mass of the powder thus obtained and 55 parts by mass of chemical fiber, paper was made with a test paper machine, dehydrated by pressing, and dried at 110 ° C. using a cylinder dryer. Thus, a synthetic paper containing the Wakkanai layer siliceous shale was obtained. The obtained Wakkanai layer siliceous shale-containing paper was formed into a corrugated structure. Then, a cylindrical dehumidification filter having a diameter of 150 mm and a length of 95 mm was prototyped by entraining this. More specifically, first, a paper containing a long Wakkanai siliceous shale having a width of 95 mm having a corrugated structure in which each of the papers having a thickness of 0.1 mm is undulated with a width of 3 mm and a height of 2.5 mm. Then, by winding the obtained paper with a uniform strength, the Wakkanai layer siliceous shale-containing paper having a corrugated structure as shown in FIG. 6 is wound in layers to form a honeycomb structure. A dehumidifying filter was obtained. In addition, although the unevenness | corrugation of drawing is drawn at the acute angle, what was used for the test is a wave shape and is formed in the curved surface.

(Prototype of dehumidification filter containing deliquescent substances)
Next, using the dehumidification filter formed by laminating the Wakkanai layer siliceous shale-containing paper obtained above, the Wakkanai layer siliceous shale was attached or contained in the deliquescent material as follows. A deliquescent substance-containing dehumidifying filter using as a dehumidifying material was obtained.

[Prototype Example 1: Deliquescent material is sodium chloride]
A sodium chloride aqueous solution having a concentration of 5% by mass was prepared, and this aqueous solution was impregnated with the dehumidification filter made of the Wakkanai layer siliceous shale-containing paper prepared above at normal pressure for 24 hours. Thereafter, the liquid on the filter surface and inside was blown off with an air spray and dried in an oven at 110 ° C. for 10 hours to prepare a chloride-containing dehumidifying filter 1 using sodium chloride as a deliquescent material in Prototype Example 1. .

[Prototype Example 2: Deliquescent material is sodium chloride + lithium chloride]
A chloride-containing dehumidifying filter 2 using two types of deliquescent substances was prepared in the same manner as in Prototype Example 1 except that a mixed aqueous solution having a sodium chloride concentration of 7% by mass and a lithium chloride concentration of 4% by mass was used. Prototype.

[Hygroscopic evaluation of dehumidifying filter]
Using each of the chloride-containing dehumidifying filters obtained in Prototype Examples 1 and 2, moisture absorption / release performance was measured as follows. Moist air adjusted to a temperature of 30 ° C. and a relative humidity of 75% was passed through each filter in the direction indicated by the arrow in FIG. 6 for 10 minutes at an air volume of 45 m ³ / h, and then the temperature was 40 ° C. and the relative humidity was 30 The dry air adjusted to% was ventilated for 10 minutes at an air flow rate of 45 m ³ / h, and this was regarded as one cycle and repeated two and a half cycles, and the mass of the filter was measured over time. The mass difference with respect to the reference value of the obtained measured value was defined as the mass change amount and is shown in FIG. The measurement value of Prototype Example 1 is indicated by a solid line, and the measurement value of Prototype Example 2 is indicated by a broken line. As shown in FIG. 2, it was confirmed that the obtained dehumidifying filters of Prototype Examples 1 and 2 can be reliably regenerated (moisture released) at a low temperature of 40 ° C. The moisture absorption / release amount at that time was 60 mg / g in 10 minutes. Also, as shown in FIG. 2, the regeneration rate tends to be slightly slower when two types of lithium chloride and sodium chloride are supported than when sodium chloride alone is supported. However, in all cases, it was confirmed that sufficient regeneration was possible at 40 ° C.

<Trial manufacture and evaluation of dehumidification rotor>
As described above, it has been confirmed that the dehumidifying filter made of the Wakkanai layer siliceous shale-containing paper can be reliably regenerated (moisture released) at a low temperature of 40 ° C. Therefore, using such a dehumidifying filter, A prototype was made and its performance and reproduction performance were evaluated. Hereinafter, these will be described.

(Production of dehumidification filter part of dehumidification rotor)
First, a sodium chloride aqueous solution having a concentration of 8% by mass is prepared, and this aqueous solution is impregnated with a Wakkanai layer siliceous shale-containing paper having a corrugated structure prepared in the same manner as described above. Wakkanai layer siliceous shale-containing paper having a width of 60 mm was prepared. Using the obtained paper, a dehumidification filter was obtained in which Wakkanai layer siliceous shale-containing paper having a corrugated structure was wound in a layered manner in the same manner as in the first and second prototypes of the dehumidification filter described above. . Using this dehumidifying filter, a circular dehumidifying rotor having a diameter of 400 mm and a length of 60 mm was prototyped as follows. In order to form the dehumidifying rotor, first, as shown in FIG. 3, a hole with a diameter of 38 mm is provided in the central portion of the dehumidifying filter obtained above, and the bearing boss 3a and the bearing 3b are fitted therein. It is. Next, this filter was fitted into the stainless steel metal frame 2, and the metal frame and the bearing boss 3 a were fixed with the spokes 4. Further, in order to receive the rotation of the motor on the outer periphery of the metal frame, a 126-tooth gear 5 was fitted and fixed to the metal frame.

(Production of rotating part of dehumidification rotor)
In order to use the dehumidifying filter obtained above as a rotating body, it was sandwiched between boxes equipped with a motor. FIG. 4 is a schematic view showing the state. As shown in FIG. 4, a core rod having a diameter of 8 mm was inserted in the center of the bearing 3, and the rotor 2 was sandwiched from both sides by two side plates 1 having a diameter of φ400 mm and cut in the center. A motor 6 is attached to one side of the side plate. The rotation speed of the motor can be controlled from 0.5 rpm to 22 rpm by changing the gear shaft of the gear box 7. A gear having 16 teeth is attached to the tip of the motor shaft 8, and the rotor can be rotated at an appropriate rotation speed by meshing with a gear (206 teeth) on the outer periphery of the rotor. ing.

(Evaluation of dehumidification rotor)
[Ventilation box for evaluation of dehumidification rotor]
The prototype dehumidification rotor was installed in a heat-insulating box capable of ventilation, and dehumidification / regeneration performance tests were performed and evaluated as follows. A cross-sectional view of the heat insulation box 1 used at this time is shown in FIG. As shown in the figure, there are partition plates 2 and 8 vertically in the front and rear of the central portion of the dehumidification rotor, and by this partition plate and dehumidification rotor 13, the heat insulation box 1 has four rooms indicated by 3, 4, 6 and 7 in the figure. It is divided into. And the cylindrical duct tube of the magnitude | size of (phi) 150mm shown by 9, 10, 11, and 12 in the figure is connected to the center upper part of each room. This ventilation box for evaluating the dehumidifying rotor is used as follows, for example. When high-temperature and high-humidity processing air adjusted to a temperature of 30 ° C. and a humidity of 75% is introduced into the room 3 from the duct tube 9, the processing air passes from the room 3 through one half of the dehumidifying rotor 13 to the room 6. Move to. At this time, moisture in the processing air is efficiently adsorbed and dehumidified by the deliquescent substance-containing dehumidifying filter having a honeycomb structure constituting the dehumidifying rotor 13. Thereafter, the dehumidified air is discharged from the duct tube 11. On the other hand, the regeneration air used for regeneration is introduced into the room 7 from the duct tube 12, and the air moves to the room 4 through a half of the dehumidification rotor 13 opposite to the treated air of the honeycomb rotor. At this time, the moisture is adsorbed by the dehumidifying filter constituting the dehumidifying rotor 13 so that the rotor is regenerated, and the air is discharged from the duct tube 10. Furthermore, the dehumidification rotor 13 is rotated by the motor 15 so that the above-described dehumidification and regeneration of air are continuously performed.

(Dehumidification / Regeneration Test-1)
Using the ventilation box 1 for evaluation of the dehumidification rotor described above, the processing air temperature is 30 ° C., the relative humidity is 75% (absolute humidity = 20.18 g / kg-DA), the regeneration air temperature is 40 ° C., the relative humidity is 27.4% (absolute After dehumidification, the dehumidification rotor was rotated at each rotation speed in the range of 1 to 22 rpm with the air volume of 150 m ³ / h at a humidity of 12.67 g / kg-DA). The air temperature and relative humidity were measured and shown in Table 2. As the dehumidifying rotor, one obtained using the Wakkanai layer siliceous shale-containing paper impregnated with an aqueous sodium chloride solution having a concentration of 8% by mass produced as described above was used. Note that DA means Dry Air.

From the above results, although depending on the number of rotations, 5 to 6 g / kg-DA of air can be dehumidified at an air volume of 150 m ³ / h, and even when the rotor type described above is used, a regeneration temperature of 40 ° C. It was confirmed that the dehumidification regeneration can be continuously performed.

(Dehumidification / Regeneration Test-2)
Next, the processing air temperature is 30 ° C., the relative humidity is 75% (absolute humidity = 20.18 g / kg-DA), the regeneration air temperature is 26 ° C., the relative humidity is 60% (absolute humidity = 12.67 g / kg-DA). The dehumidification rotor produced based on the Wakkanai layer siliceous shale-containing paper impregnated with an aqueous sodium chloride solution having a concentration of 8% by mass as used above was evaluated under the following conditions. That is, the amount of dehumidification when the air volume is 150 m ³ / h and the rotor rotational speed is rotated at each rotational speed in the range of 1 to 22 rpm, the temperature of the dehumidified air, and the relative humidity are measured. Indicated.

  From the above results, the deliquescent material-supported Wakkanai siliceous shale rotor can obtain the same dehumidifying performance as that at 40 ° C regeneration by increasing the rotor speed to 7.5 rpm or higher even at room temperature of 26 ° C. Became clear. In addition, in the case of normal temperature regeneration at 26 ° C., the treated air at 30 ° C. is dehumidified when passing through the rotor, and heat exchange with the regenerated air at 26 ° C. It was found to be lower than 30 ° C. In particular, when the speed is increased to 22 rpm, the air temperature after dehumidification is 26.8 ° C. and the relative humidity is 63.5%, and the function as a total heat exchanger in which dehumidification and heat exchange are performed simultaneously can be expressed. Results were obtained.

  According to the present invention, it is possible to provide a dehumidifying filter having an excellent dehumidifying ability and an excellent regeneration ability at a low temperature. Therefore, by applying the dehumidifying filter of the present invention as a desiccant rotor, it becomes possible to omit equipment such as a heater, and it is possible to achieve downsizing and energy saving of the desiccant air conditioner. The future utility value when applied to the above is enormous.

FIG.
1: Dehumidifying filter 2: Gold frame 3a: Bearing boss 3b: Bearing 4: Spoke 5: Gear Fig. 4
1: Side plate 2: Rotor 3: Bearing 6: Motor 7: Gearbox 8: Motor shaft diagram 5
1: Insulation box, evaluation ventilation box 2, 8: Partition plate 3, 4, 6, 7: Room 9, 10, 11, 12: Duct tube 13: Dehumidification rotor 15: Motor

Claims (5)

A dehumidifying filter,
The substrate is made to adhere or contain a dehumidifying material made of siliceous shale having a large number of pores having an average pore diameter of 3 to 18 nm and a specific surface area of 80 m ² / g or more,
The substrate is a paper substrate, a nonwoven fabric substrate or a ceramic substrate;
Said dehumidifying material, within at least pores of the siliceous shale, sodium chloride is being deposited within the 10-150 mg / g, it is excellent from the intermediate moisture range in dehumidification capacity of over the high humidity range Dehumidification filter characterized by. The dehumidifying filter according to claim 1 , wherein the base material has a corrugated structure or a honeycomb structure. The dehumidifying filter according to claim 1 , wherein the base material is a non-woven fabric base material, and the structure is a structure formed by laminating non-woven fabrics. The dehumidifying filter according to any one of claims 1 to 3 , wherein the dehumidifying material is attached by coating a substrate with a coating agent containing the dehumidifying material and a breathable binder. A desiccant air conditioner, wherein the dehumidifying filter according to any one of claims 1 to 4 is applied to a desiccant rotor.

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