Ceramic moisture absorbent, air conditioner, and desiccant air conditioner

Abstract

Disclosed is a ceramic moisture absorbent which comprises a plurality of fibrous particles that are formed of a ceramic which contains titanium, potassium, and oxygen. The plurality of fibrous particles form a plurality of pores between each other. The plurality of fibrous particles have specific pores that have a pore diameter of 10-80 nm inclusive as measured by a gas adsorption method. The total pore volume of the specific pores is 1 cm3 / g or more per unit mass of the ceramic moisture absorbent.

Description

Ceramic moisture absorbents, air conditioners, and desiccant air conditioners

[0001] The present invention relates to a ceramic moisture absorbent, an air conditioner, and a desiccant air conditioner.

[0002] BACKGROUND ART Ceramic moisture absorbents made of ceramics have been known (for example, see Patent Document 1).

[0003] Patent No. 3944233

[0004] However, even with the prior art such as that of Patent Document 1, there is still room for improvement in the technology for improving the water vapor adsorption performance of ceramic moisture absorbents.

[0005] An object of the present invention is to provide a technique for improving the water vapor adsorption performance of a ceramic moisture absorbent.

[0006] The present invention has been made to solve at least part of the above-mentioned problems, and can be realized in the following aspects.

[0007] (1) According to one aspect of the present invention, there is provided a ceramic moisture absorbent, which comprises a plurality of fibrous particles formed of a ceramic containing titanium, potassium, and oxygen, the plurality of fibrous particles having a plurality of pores formed therebetween, the pores having specific pores with a pore diameter of 10 nm to 80 nm as measured by a gas adsorption method, and the total pore volume of the specific pores being 1 cm per unit mass of the ceramic moisture absorbent. 3 / g or more.

[0008] According to this configuration, the ceramic moisture absorbent comprises a plurality of fibrous particles formed of ceramic containing titanium, potassium, and oxygen. In the ceramic moisture absorbent, the plurality of fibrous particles form a plurality of pores including specific pores having a pore diameter of 10 nm or more and 80 nm or less as measured by a gas adsorption method, and the total pore volume of the specific pores is 1 cm or less per unit mass of the ceramic moisture absorbent. 3 / g or more. Here, the "gas adsorption method" is a method in which molecules with known surface area and volume are adsorbed onto an object to be measured, and the specific surface area and pore distribution of the object to be measured are measured from the amount of adsorbed molecules. This allows the ceramic moisture absorbent to adsorb a relatively large amount of water vapor.

[0009] (2) In the ceramic moisture absorbent of the above embodiment, the ratio of the total pore volume of the specific pores to the total pore volume of pores having a pore diameter of 1 nm to 400 nm measured by gas adsorption may be 60% or more. According to this configuration, most of the pores formed in the ceramic moisture absorbent have a pore diameter of 10 nm to 80 nm measured by gas adsorption. This allows a relatively large amount of water vapor to be adsorbed.

[0010] (3) In the ceramic moisture absorbent of the above form, the specific surface area measured by the gas adsorption method is 200 m 2 / g or more. According to this configuration, the ceramic moisture absorbent has a relatively large specific surface area measured by a gas adsorption method, which allows it to adsorb even more water vapor.

[0011] (4) In the ceramic moisture absorbent of the above form, in a water vapor adsorption / desorption isothermal measurement by a gas adsorption method, the water vapor relative humidity is 95% in an environment of 1000 cm 3 / g or more of water vapor, and in an environment with a relative humidity of 98% water vapor, 3 According to this configuration, the ceramic moisture absorbent can adsorb a relatively large amount of water vapor in an environment where the relative humidity of the water vapor is relatively high, that is, 95% or more.

[0012] (5) In the ceramic moisture absorbent of the above embodiment, in a state where water vapor is adsorbed, the amount of adsorbed water vapor desorbed may be maximized at a temperature of 50° C. to 70° C. According to this configuration, the ceramic moisture absorbent can desorb a relatively large amount of adsorbed water vapor at a relatively low temperature of 50° C. to 70° C. This allows the ceramic moisture absorbent that has adsorbed water vapor to be regenerated with relatively little energy.

[0013] (6) According to another aspect of the present invention, there is provided an air conditioner. The air conditioner includes the ceramic moisture absorbent of the above aspect. According to this configuration, the air conditioner has a pore volume of 1 cm 3 The ceramic moisture absorbent has specific pores of 1 / g or more, which can improve the humidity control performance of the air conditioner.

[0014] (7) According to yet another aspect of the present invention, there is provided a desiccant air conditioner. This desiccant air conditioner includes the ceramic moisture absorbent of the above aspect. According to this configuration, the desiccant air conditioner has a pore volume of 1 cm 3 The desiccant air conditioner is provided with a ceramic moisture absorbent having specific pores of 1 / g or more. This improves the humidity control performance of the desiccant air conditioner.

[0015] The present invention can be realized in various forms, for example, in the form of a method for manufacturing a ceramic moisture absorbent, an apparatus equipped with a ceramic moisture absorbent, a method for controlling an apparatus equipped with a ceramic moisture absorbent, a computer program for causing an apparatus equipped with a ceramic moisture absorbent to perform moisture absorption, etc.

[0016] FIG. 1 is a diagram showing a schematic configuration of a desiccant air conditioner of a first embodiment; FIG. 2 is a first SEM photograph of a ceramic moisture absorbent of a first embodiment; FIG. 3 is a second SEM photograph of a ceramic moisture absorbent of a first embodiment; FIG. 4 is a fourth SEM photograph of a ceramic moisture absorbent of a first embodiment; FIG. 5 is a diagram explaining the relationship between pore diameter and pore volume of a ceramic moisture absorbent; FIG. 6 is a diagram explaining the water vapor adsorption isotherm of a ceramic moisture absorbent; FIG. 7 is a diagram explaining the relationship between the temperature of a ceramic moisture absorbent and the amount of water vapor desorption; and FIG. 8 is a diagram showing a schematic configuration of an air conditioner of a second embodiment.

[0017] <First Embodiment> Fig. 1 is a diagram showing the schematic configuration of a desiccant air conditioner according to the first embodiment. The desiccant air conditioner 10 of this embodiment is an apparatus that adjusts (conditions) the humidity indoors in a building, such as a factory, using a ceramic moisture absorbent 1. The desiccant air conditioner 10 includes a desiccant rotor 11 having the ceramic moisture absorbent 1, a pre-cooling coil 12, a regenerative heater 13, a heat pump 14, and two fans 15 and 16. The ceramic moisture absorbent 1 is accommodated in the desiccant rotor 11.

[0018] A desiccant rotor 11 provided in a desiccant air conditioner 10 is filled with a ceramic moisture absorbent 1. The desiccant rotor 11 is arranged to rotate in the direction of the outline arrow R1 in Figure 1. The temperatures of a pre-cooling coil 12 and a regenerative heater 13 are each controlled by a heat pump 14.

[0019] In the desiccant air conditioner 10, outside air is introduced into the desiccant air conditioner 10 from outdoors by the suction force of the fan 15 and cooled in the pre-cooling coil 12. Water vapor contained in the cooled outside air is removed by being adsorbed by the ceramic moisture absorbent 1 in the desiccant rotor 11. The outside air from which water vapor has been removed by the desiccant rotor 11 is supplied indoors as supply air. Meanwhile, a portion of the indoor air is introduced into the desiccant air conditioner 10 as return air by the suction force of the fan 16. The return air introduced into the desiccant air conditioner 10 is heated in the regenerative heater 13 and then passes through the desiccant rotor 11. The heated return air passing through the desiccant rotor 11 heats the ceramic moisture absorbent 1, which has adsorbed the water vapor contained in the cooled outside air. As a result, the water vapor adsorbed by the ceramic moisture absorbent 1 is desorbed and contained in the heated return air. The return air containing the water vapor is discharged outdoors as exhaust air. In this way, the desiccant air conditioner 10 adjusts the indoor humidity so that the indoor humidity is lower than the outdoor humidity.

[0020] The ceramic moisture absorbent 1 of this embodiment includes a plurality of fibrous particles formed of ceramic. The ceramic forming the ceramic moisture absorbent 1 contains titanium, potassium, and oxygen. The plurality of fibrous particles included in the ceramic moisture absorbent 1 form a plurality of pores among each other.

[0021] FIG. 2 is a first SEM photograph of the ceramic moisture absorbent 1 of this embodiment. FIG. 3 is a second SEM photograph of the ceramic moisture absorbent 1 of this embodiment. FIG. 4 is a third SEM photograph of the ceramic moisture absorbent 1 of this embodiment. Each of FIGS. 2 to 4 shows SEM photographs of the surface of the ceramic moisture absorbent 1 of this embodiment at different magnifications. FIG. 2 is an SEM photograph of the surface of the ceramic moisture absorbent 1 taken at 10,000x magnification, in which aggregates 2 of multiple fibrous particles, which at first glance appear to be lumps, can be seen. FIG. 3 is an SEM photograph of a portion of the surface of the ceramic moisture absorbent 1 included in the SEM photograph of FIG. 2 taken at 25,000x magnification. In the SEM photograph of FIG. 3 taken at 25,000x magnification, multiple fibrous particles forming aggregates 2 can be seen. FIG. 4 is an SEM photograph of a portion of the surface of the ceramic moisture absorbent 1 included in the SEM photograph of FIG. 3 taken at 100,000x magnification. 4 shows that the aggregate 2 is formed by overlapping a plurality of fibrous particles 3 arranged in various directions. In the ceramic moisture absorbent 1 of this embodiment, a plurality of pores 4 are formed by the overlapping of a plurality of fibrous particles 3 as shown in FIG.

[0022] Figure 5 is a fourth SEM photograph of the ceramic moisture absorbent of the first embodiment. The SEM photograph shown in Figure 5 is the same as that shown in Figure 4, but the outline of one fibrous particle 3a among the multiple fibrous particles 3 shown in Figure 4 is indicated by a dotted line CL1 to make it easier to understand. In Figure 5, for example, the fibrous particle 3a whose outline is indicated by the dotted line CL1 has a length L1 of 740 nm and a width W1 of 15.8 nm. As such, the fibrous particles 3 included in the ceramic moisture absorbent 1 have a relatively elongated shape. Note that the length and width of the fibrous particles 3 included in the ceramic moisture absorbent 1 are not limited to these.

[0023] Next, a method for manufacturing the ceramic moisture absorbent 1 will be described. In manufacturing the ceramic moisture absorbent 1 of this embodiment, first, potassium hydroxide powder as a reagent is mixed with pure water to prepare a potassium hydroxide aqueous solution with a concentration of 20 mol / kg. Next, the prepared potassium hydroxide aqueous solution is mixed with titanium oxide (TiO2) powder as a reagent in a weight ratio of 100:1 to prepare a mixture. In the manufacturing method for the ceramic moisture absorbent 1 of this embodiment, the concentration of the potassium hydroxide aqueous solution is preferably 10 mol / kg or more and 20 mol / kg or less.

[0024] Next, the prepared mixture is sealed in a high-pressure reaction decomposition vessel (HU-50, manufactured by San-Ai Scientific Co., Ltd.), and the high-pressure reaction decomposition vessel containing the mixture is set in a constant-temperature dryer. In the constant-temperature dryer, the mixture is pressurized and dried at a temperature of 130°C for 20 hours at a temperature increase / decrease rate of 3°C / min, followed by hydrothermal treatment. In the method for producing the ceramic moisture absorbent 1 of this embodiment, the temperature in the hydrothermal treatment is preferably 130°C or higher and 160°C or lower.

[0025] After the hydrothermal treatment, the pressure inside the high-pressure reaction and decomposition vessel is reduced by natural cooling until the temperature of the entire high-pressure reaction and decomposition vessel reaches or falls below 30° C. After the pressure inside the high-pressure reaction and decomposition vessel is reduced, the high-pressure reaction and decomposition vessel is opened in a draft, and the mixture after the hydrothermal treatment (hydrothermally treated product) is removed from the high-pressure reaction and decomposition vessel.

[0026] Next, the pH of the hydrothermally treated product removed from the high-pressure reactive decomposition vessel is adjusted. Specifically, the pH of the hydrothermally treated product is adjusted to a weak acidic value, specifically, a pH in the range of 2 to 4, by adding hydrochloric acid dropwise to the hydrothermally treated product.

[0027] Next, the pH-adjusted hydrothermally treated product (volume: 3 ml to 40 ml) is placed in a centrifuge tube, pure water is added so that the solvent filling rate is approximately 80%, and a first centrifugation operation is performed under the conditions of a rotation speed of 4500 rpm and a rotation time of 5 minutes x 3 times (total of 15 minutes). After the first centrifugation operation, the solvent portion in the centrifuge tube is removed, pure water is added, and a second centrifugation operation is performed. The set of the first centrifugation operation, the addition of pure water, and the second centrifugation operation is repeated several times to remove salt from the hydrothermally treated product.

[0028] The hydrothermally treated product from which the salt has been removed is placed in a petri dish, pre-frozen in a freezer, and then freeze-dried for 10 hours. After freeze-drying is complete, the powder remaining in the petri dish is the ceramic moisture absorbent 1. The ceramic moisture absorbent 1 is produced in this manner.

[0029] FIG. 6 is a diagram illustrating the relationship between the pore size and pore volume of the pores formed in the ceramic moisture absorbent. In FIG. 6, the relationship between the pore size and pore volume of the pores formed in the ceramic moisture absorbent 1 of this embodiment is shown by a solid line P1, and the relationship between the pore size and pore volume of the pores formed in the ceramic moisture absorbent of the comparative example is shown by a dashed line P0. The relationship between the pore size and pore volume of the pores shown in FIG. 6 was measured by a gas adsorption method. Here, the "gas adsorption method" refers to a method in which molecules with known surface area and volume are adsorbed onto the object to be measured, and the specific surface area and pore distribution of the object to be measured are measured from the amount of adsorbed molecules. Specifically, the relationship between the pore size and pore volume of the pores shown in FIG. 6 was calculated by the BJH method (Barrett-Joyner-Halenda method) from the results of nitrogen adsorption isothermal measurement using a constant volume method using an autosorb-iQ (manufactured by Anton Paar).

[0030] Here, a method for manufacturing a ceramic moisture absorbent of the comparative example will be described. First, a comparative mixture was prepared by mixing titanium oxide powder with a potassium hydroxide aqueous solution having a concentration of 17 mol / kg in a weight ratio of 100:1. Next, the sealed high-pressure reaction / decomposition vessel was placed in a constant-temperature dryer, and pressure drying was performed in the constant-temperature dryer at a temperature of 110°C for 20 hours with a temperature increase / decrease rate of 3°C / min, followed by hydrothermal treatment. After the hydrothermal treatment, the high-pressure reaction / decomposition vessel was naturally cooled until the temperature of the entire vessel was 30°C or less. The pH of the hydrothermally treated product of the comparative example removed from the high-pressure reaction / decomposition vessel was then adjusted by adding hydrochloric acid dropwise so that the pH was between 2 and 4. The pH-adjusted hydrothermal treatment product of the comparative example was added with pure water, and the first centrifugation was performed under the conditions of a rotation speed of 4500 rpm and a rotation time of 5 minutes x 3 times (total 15 minutes), the solvent portion in the centrifuge tube was removed, and then pure water was added, followed by a second centrifugation operation, which were repeated multiple times, followed by pre-freezing and 10 hours of freeze-drying, to produce the comparative ceramic moisture absorbent. Comparing the manufacturing method of the ceramic moisture absorbent 1 of this embodiment with the manufacturing method of the comparative ceramic moisture absorbent, the temperature conditions in the hydrothermal treatment are different.

[0031] As shown in FIG. 6, the ceramic moisture absorbent 1 of this embodiment has specific pores with a pore diameter of 10 nm or more and 80 nm or less as measured by a gas adsorption method, and the total pore volume of the specific pores is 1 cm or less per unit mass of the ceramic moisture absorbent 1. 3 Specifically, the ceramic moisture absorbent 1 has a total pore volume of 1.49 cm3 for pores having a pore diameter of 10.2 nm or more and 83.7 nm or less as measured by a gas adsorption method. 3 On the other hand, in the ceramic moisture absorbent of the comparative example, the total pore volume of pores having a pore diameter of 10 nm or more and 80 nm or less is 1 cm 3 / g. Therefore, the pore volume of the pores having a pore diameter of 10 nm or more and 80 nm or less in the ceramic moisture absorbent 1 is larger than that of the ceramic moisture absorbent of the comparative example. Note that in the ceramic moisture absorbent 1, the total pore volume of the specific pores is, for example, 2 cm per unit mass of the ceramic moisture absorbent 1. 3 / g or less, and3 / g or more is preferable, and 1.4 cm 3 / g or more is more preferable.

[0032] As shown in FIG. 6, the pores of the ceramic moisture absorbent 1 of this embodiment have a pore diameter of 1 nm to 400 nm measured by a gas adsorption method. The ratio of the total pore volume of specific pores to the total pore volume of specific pores is 60% or more. Specifically, in the ceramic moisture absorbent 1, the ratio of the total pore volume of specific pores to the total pore volume of specific pores having a pore diameter of 1.0074 nm to 386.2477 nm measured by a gas adsorption method is 70.7%. In addition, in the ceramic moisture absorbent 1, the ratio of the total pore volume of specific pores to the total pore volume of specific pores having a pore diameter of 1 nm to 400 nm is, for example, 80% or less. Furthermore, the ratio of the total pore volume of specific pores to the total pore volume of specific pores having a pore diameter of 1 nm to 400 nm is preferably 70% or more.

[0033] The ceramic moisture absorbent 1 of this embodiment has a specific surface area of ​​200 m2 measured by a gas adsorption method. 2 Specifically, in a measurement by a BET multipoint method using QUADRASORB evo (manufactured by Anton Paar), the specific surface area of ​​the ceramic moisture absorbent 1 is 309 m 2 / g. The specific surface area of ​​the ceramic moisture absorbent 1 is, for example, 400 m 2 / g or less.

[0034] FIG. 7 is a diagram illustrating the water vapor adsorption isotherm of a ceramic moisture absorbent. In FIG. 7, the adsorption curve of the ceramic moisture absorbent 1 of this embodiment is shown by a solid line P1a, and the desorption curve is shown by a dashed line P1d. In FIG. 7, the adsorption curve of the ceramic moisture absorbent of the comparative example is shown by a solid line P0a thinner than the solid line P1a, and the desorption curve is shown by a dashed line P0d thinner than the thin line P1d. The water vapor adsorption isotherm shown in FIG. 7 shows the results of water vapor adsorption isotherm measurement using a constant volume method using a Microtrackbell BELSORPmax II. The comparative ceramic moisture absorbent used for comparison in FIG. 7 is a ceramic moisture absorbent manufactured by the same manufacturing method as the comparative ceramic moisture absorbent whose pore diameter and pore volume relationship is shown in FIG. 6.

[0035] The ceramic moisture absorbent 1 of this embodiment has a water vapor adsorption / desorption isothermal measurement by gas adsorption method, and has a water vapor relative humidity of 1000 cm in an environment where the relative humidity of water vapor is 95%. 3 / g or more of water vapor, and in an environment with a relative humidity of 98% water vapor, 3 7, when the relative humidity of the water vapor is 94.92%, the ceramic moisture absorbent 1 adsorbs 1014.9 cm 3 / g of water vapor is adsorbed, and when the relative humidity of the water vapor is 98.04%, 1667.8 cm 3 On the other hand, the ceramic moisture absorbent of the comparative example can adsorb 693.1 cm / g of water vapor when the relative humidity of the water vapor is 94.55%. 3 / g of water vapor is adsorbed, and when the relative humidity of the water vapor is 98.18%, 827.4 cm 3 It was confirmed that the ceramic moisture absorbent 1 adsorbed water vapor at a rate of 1700 cm / g. Therefore, the ceramic moisture absorbent 1 adsorbed a larger amount of water vapor than the ceramic moisture absorbent of the comparative example. In addition, in the ceramic moisture absorbent 1, in an environment where the relative humidity of water vapor was 98%, water vapor adsorbed at a rate of 1700 cm / g. 3 / g or less.

[0036] FIG. 8 illustrates the relationship between temperature and the amount of water vapor desorbed from a ceramic moisture absorbent. FIG. 8 shows the relationship between the temperature and the amount of water vapor desorbed from the ceramic moisture absorbent 1 of this embodiment, which adsorbs water vapor, upon heating. The relationship between temperature and the amount of water vapor desorbed shown in FIG. 8 was measured using thermally evolved gas mass spectrometry (TPD / MS). The vertical axis in FIG. 8 represents the measured intensity corresponding to the amount of water vapor desorbed from the ceramic moisture absorbent 1, and the solid line P1m in FIG. 8 represents the temperature change in the measured intensity corresponding to the amount of desorbed water vapor. FIG. 8 also shows a virtual line VL1 that reflects the trend of intensity change at temperatures above 200°C to temperatures below 200°C. In the measurement results shown in FIG. 8, the virtual line VL1 is used as the reference, and the farther the solid line P1m is from the virtual line VL1, the greater the amount of water vapor desorbed.

[0037] When the ceramic moisture absorbent 1 of this embodiment is in a state of adsorbing water vapor, the amount of adsorbed water vapor desorbed is maximized at a temperature of 50° C. or higher and 70° C. or lower. Specifically, as shown in FIG. 8 , the solid line P1m is farthest from the imaginary line VL1 at approximately 60° C. Note that the ceramic moisture absorbent 1 desorbs water vapor even at temperatures of 25° C. or lower, meaning that water vapor is desorbed at relatively low temperatures.

[0038] According to the ceramic moisture absorbent 1 of this embodiment described above, the ceramic moisture absorbent 1 includes a plurality of fibrous particles 3 formed of ceramic containing titanium, potassium, and oxygen. In the ceramic moisture absorbent 1, the plurality of fibrous particles 3 form a plurality of pores 4 including specific pores having a pore diameter of 10 nm or more and 80 nm or less as measured by a gas adsorption method. The total pore volume of the specific pores is 1 cm per unit mass of the ceramic moisture absorbent. 3 / g or more. This allows the ceramic moisture absorbent to adsorb a relatively large amount of water vapor.

[0039] Furthermore, according to the ceramic moisture absorbent 1 of this embodiment, the ratio of the total pore volume of specific pores to the total pore volume of pores having a pore diameter of 1 nm to 400 nm measured by gas adsorption is 60% or more. Thus, most of the pores 4 formed in the ceramic moisture absorbent 1 have a pore diameter of 10 nm to 80 nm measured by gas adsorption. This allows a relatively large amount of water vapor to be adsorbed.

[0040] Furthermore, according to the ceramic moisture absorbent 1 of this embodiment, the ceramic moisture absorbent 1 has a specific surface area of ​​200 m as measured by a gas adsorption method. 2 / g or more, which is relatively large, and this allows even more water vapor to be adsorbed.

[0041] Furthermore, according to the ceramic moisture absorbent 1 of this embodiment, in a water vapor adsorption / desorption isothermal measurement by a gas adsorption method, the ceramic moisture absorbent 1 has a water vapor desorption rate of 1000 cm in an environment where the relative humidity of water vapor is 95%. 3 / g or more of water vapor, and in an environment with a relative humidity of 98% water vapor, 3 The ceramic moisture absorbent 1 of this embodiment can adsorb a relatively large amount of water vapor in an environment with a relatively high relative humidity of 95% or more.

[0042] Furthermore, according to the ceramic moisture absorbent 1 of this embodiment, in a state where water vapor is adsorbed, the amount of adsorbed water vapor desorbed is maximized at a temperature of 50° C. or higher and 70° C. or lower. In this way, the ceramic moisture absorbent 1 can desorb a relatively large amount of adsorbed water vapor at a relatively low temperature of 50° C. or higher and 70° C. or lower. This allows the ceramic moisture absorbent that has adsorbed water vapor to be regenerated with relatively little energy.

[0043] Furthermore, according to the desiccant air conditioner 10 of this embodiment, the ceramic moisture absorbent 1 having the above-described characteristics is provided in the desiccant rotor 11. This allows the humidity control performance of the desiccant air conditioner 10 to be improved.

[0044] <Second embodiment> Fig. 9 is a diagram showing a schematic configuration of an air conditioner of a second embodiment. An air conditioner 20 of the second embodiment is different from the desiccant air conditioner 10 of the first embodiment (Fig. 1) in the way in which the ceramic moisture absorbent is used.

[0045] An air conditioner 20 of the second embodiment reduces indoor humidity by using a ceramic moisture absorbent 1. The air conditioner 20 includes a pipe 21 and a moisture absorbing unit 22 that houses the ceramic moisture absorbent 1. In addition to the ceramic moisture absorbent 1, the moisture absorbing unit 22 may include a fan, a heating coil, a cooling coil, a heat pump, or the like.

[0046] Indoor air is introduced as return air into the piping 21 through the inlet 21a. When the air flowing through the piping 21 passes through the moisture absorption section 22, water vapor is adsorbed by the ceramic moisture absorbent 1, reducing the humidity of the air. The air with reduced humidity passes through the outlet 21b and is supplied indoors as supply air. The introduction of return air into the piping 21 may be by forced air supply using a fan or natural intake.

[0047] According to the air conditioner 20 of this embodiment described above, the air conditioner 20 has a pore volume of 1 cm 3 The ceramic moisture absorbent 1 has specific pores of 1 / g or more. This can improve the humidity control performance of the air conditioner 20.

[0048] <Modifications of this embodiment> The present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the spirit of the present invention. For example, the following modifications are also possible.

[0049] [Variation 1] In the above-described embodiment, the ceramic moisture absorbent 1 has a plurality of pores 4 in which the ratio of the total pore volume of specific pores to the total pore volume of pores having a pore diameter of 1 nm to 400 nm measured by gas adsorption is 60% or more. The ratio of the pore volume of specific pores is not limited to this. The larger the ratio of the total pore volume of specific pores to the total pore volume of pores having a pore diameter of 1 nm to 400 nm measured by gas adsorption, the greater the amount of water vapor adsorption.

[0050] [Modification 2] In the above embodiment, the ceramic moisture absorbent 1 has a specific surface area of ​​200 m2 measured by gas adsorption method. 2 / g or more. The specific surface area is 200 m 2 / g, but the larger it is, the greater the amount of water vapor adsorption will be.

[0051] [Modification 3] In the above-described embodiment, the ceramic moisture absorbent 1 has a water vapor adsorption / desorption isothermal measurement by gas adsorption method, and the water vapor relative humidity is 1000 cm in an environment of 95%. 3 / g or more of water vapor, and in an environment with a relative humidity of 98% water vapor, 3 / g or more of water vapor is adsorbed. The amount of water vapor adsorbed by the ceramic moisture absorbent 1 of this embodiment does not necessarily have to satisfy this relationship.

[0052] [Modification 4] In the above embodiment, the ceramic moisture absorbent 1, while adsorbing water vapor, is set to have a maximum desorption amount of the adsorbed water vapor at a temperature of 50°C or higher and 70°C or lower. The temperature range in which the ceramic moisture absorbent 1 has a maximum desorption amount of water vapor is not limited to this. For example, the desorption amount of water vapor may be a maximum at room temperature or a temperature range near room temperature or a temperature slightly higher than room temperature. In this case, the energy required for regenerating the ceramic moisture absorbent can be reduced.

[0053] [Modification 5] In the above-described embodiment, the ceramic moisture absorbent 1 is used in the desiccant air conditioner 10 or the air conditioner 20. However, the technical field to which the ceramic moisture absorbent 1 is applied is not limited to this. The ceramic moisture absorbent 1 may be used in any device or situation where a moisture absorption function is required.

[0054] This aspect has been described above based on embodiments and modifications. However, the above-described embodiments are intended to facilitate understanding of this aspect and are not intended to limit this aspect. This aspect may be modified or improved without departing from the spirit and scope of the claims, and equivalents thereof are included in this aspect. Furthermore, if a technical feature is not described as essential in this specification, it may be deleted as appropriate.

[0055] (Application Example 1) A ceramic moisture absorbent comprises a plurality of fibrous particles formed of a ceramic containing titanium, potassium, and oxygen, the plurality of fibrous particles forming a plurality of pores therebetween, the plurality of fibrous particles having specific pores with a pore diameter of 10 nm or more and 80 nm or less as measured by a gas adsorption method, and the total pore volume of the specific pores is 1 cm or less per unit mass of the ceramic moisture absorbent. 3 / g or more. (Application Example 2) The ceramic moisture absorbent according to Application Example 1, wherein the ratio of the total pore volume of the specific pores to the total pore volume of pores having a pore diameter of 1 nm or more and 400 nm or less as measured by a gas adsorption method is 60% or more. (Application Example 3) The ceramic moisture absorbent according to Application Example 1 or Application Example 2, wherein the specific surface area measured by a gas adsorption method is 200 m 2 / g or more in a water vapor adsorption / desorption isothermal measurement by a gas adsorption method. 3 / g or more of water vapor, and in an environment with a relative humidity of 98% water vapor, 3 / g or more of water vapor. (Application Example 5) The ceramic moisture absorbent according to any one of Application Examples 1 to 4, wherein, in a state where water vapor is adsorbed, the amount of adsorbed water vapor desorbed is maximized at a temperature of 50°C or higher and 70°C or lower. (Application Example 6) An air conditioning system comprising the ceramic moisture absorbent according to any one of Application Examples 1 to 5. (Application Example 7) A desiccant air conditioning system comprising the ceramic moisture absorbent according to any one of Application Examples 1 to 5.

[0056] REFERENCE SIGNS LIST 1... ceramic moisture absorbent 3... fibrous particles 4... pores 10... desiccant air conditioner 20... air conditioner

Claims

1. A ceramic moisture absorbent comprising a plurality of fibrous particles formed of a ceramic containing titanium, potassium, and oxygen, the plurality of fibrous particles forming a plurality of pores between each other, the pores having specific pores with a pore diameter of 10 nm or more and 80 nm or less as measured by a gas adsorption method, and the total pore volume of the specific pores being less than 1 cm per unit mass of the ceramic moisture absorbent. 3 / g or more.

2. A ceramic moisture absorbent according to claim 1, wherein the ratio of the total pore volume of the specific pores to the total pore volume of pores having a pore diameter of 1 nm or more and 400 nm or less as measured by a gas adsorption method is 60% or more.

3. The ceramic moisture absorbent according to claim 1 or 2, wherein the specific surface area measured by gas adsorption method is 200 m 2 / g or more.

4. The ceramic moisture absorbent according to claim 1 or 2, wherein in a water vapor adsorption / desorption isothermal measurement by gas adsorption method, the relative humidity of the water vapor is 1000 cm in an environment of 95%. 3 / g or more of water vapor, and in an environment with a relative humidity of 98% water vapor, 3 1. A ceramic moisture absorbent characterized by adsorbing water vapor in an amount of 1 / 2 g or more.

5. A ceramic moisture absorbent according to claim 1 or 2, characterized in that, in a state in which water vapor is adsorbed, the amount of adsorbed water vapor desorbed reaches a maximum at a temperature of 50°C or higher and 70°C or lower.

6. An air conditioning device comprising the ceramic moisture absorbent according to claim 1 or 2.

7. A desiccant air conditioner comprising the ceramic moisture absorbent according to claim 1 or 2.

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