JPH10263394A - Improved adsorbent, its production and adsorption refrigerating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an improved adsorbent having high adsorbing performance even in a low relative pressure range by sticking an additive adsorbent to the surfaces of the pores in a basic adsorbent. SOLUTION: An additive adsorbent (y) is stuck to the surfaces of the pares in a basic adsorbent (x) to obtain the objective improved adsorbent used as an adsorbent for a refrigerating cycle. The adsorbents (x), (y) are different adsorbents causing reversal in the extent of equilibrium adsorption to a refrigerant in accordance with levels of relative pressure (relative humidity %) which is the ratio of the vapor pressure of the refrigerant to the satd. vapor pressure of the refrigerant around each of the adsorbents. One of the adsorbents having a larger extent of equilibrium adsorption than the other on the high relative pressure side is used as the basic adsorbent (x) and the other having a larger extent of equilibrium adsorption than the adsorbent (x) on the low relative pressure side is used as the additive adsorbent (y). The improved adsorbent attains a large extent of adsorption attained by the adsorbent (x) on the high relative pressure side from the low relative pressure side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an improved adsorbent used for adsorbing various substances, a method for producing the same, and an adsorption refrigerator using the improved adsorbent.

[0002]

2. Description of the Related Art Conventionally, activated carbon, silica gel, spheroidized silica gel (Sovabead), zeolite, activated alumina and calcium silicate (Fluorit) have been used as adsorbents.
Various types such as e) are known.

[0003] As for the adsorption refrigerator, conventionally, water is used as a refrigerant, and silica gel or zeolite is used as an adsorbent for a refrigeration cycle.

[0004]

As can be seen from the example of FIG. 4, the adsorbent such as silica gel or zeolite (molecular sieve: molecular sieve 5A) has a relative pressure (saturated vapor of the substance to be adsorbed around the adsorbent). Even in a low relative pressure range in which the ratio of the vapor pressure p of the substance to be adsorbed to the pressure p ₀ (p / p ₀ ) is 0.4 or less or 0.2 or less, it exhibits a certain degree of adsorption (equilibrium adsorption amount). However, for example, there is no adsorbent that exhibits high adsorptivity (large equilibrium adsorption amount) in a low relative pressure range as activated carbon exhibits in a high relative pressure range. In this regard, in various fields using adsorption, In order to further improve the efficiency, it is desired to develop an adsorbent having more excellent adsorptivity in a low relative pressure range.

[0005] In particular, in an adsorption refrigerator, the relative pressure in the adsorption / evaporation step is generally determined from the operating conditions such as the required temperature of the generated cold heat and the temperature of the cooling medium used for cooling the adsorbent during adsorption. In many cases, silica gel, zeolite, or the like, which exhibits a certain degree of adsorptivity (equilibrium adsorption amount) even in this relative pressure range, must be used as the adsorbent for the refrigeration cycle. I can't get it. However, due to this restriction, there are problems that the refrigerating capacity is limited, and that the required amount of the adsorbent for the refrigerating cycle becomes large in order to obtain the required refrigerating capacity, resulting in an increase in the size of the apparatus.

FIG. 4 shows an example of isothermal adsorption of water vapor (29
The relationship between the relative pressure p / p ₀ (in other words, the relative humidity%) of each adsorbent at 8 ° K) and the equilibrium adsorption amount q (kgH ₂ O / kg adsorbent) is shown.

[0007] In view of the above circumstances, a first object of the present invention is to provide an improved adsorbent which exhibits high adsorptivity even in a low relative pressure range. A second object of the present invention is to provide a production method suitable for producing the improved adsorbent. A third object of the present invention is to provide an adsorption refrigerator capable of effectively improving the refrigerating capacity and effectively reducing the size of the apparatus using the improved adsorbent.

[0008]

[Means for Solving the Problems]

[1] In the first aspect of the present invention, the equilibrium adsorption amount to the adsorption target substance is determined by the relative pressure (the value of the ratio of the vapor pressure of the adsorption target substance to the saturated vapor pressure of the adsorption target substance around the adsorbent). A different type of adsorbent that causes inversion is used. Of these adsorbents, the adsorbent exhibiting a larger equilibrium adsorption amount on the high relative pressure side than the other adsorbent is used as the main adsorbent, and the equilibrium adsorption on the low relative pressure side is larger than the main adsorbent. With the adsorbent indicating the amount as the impregnated adsorbent, the impregnated adsorbent is impregnated on the inner surface of the pores of the main adsorbent.

In other words, in the case of adsorbents having different adsorption characteristics, as can be seen from FIG. 4, the equilibrium adsorption amount (adsorptivity) for the substance to be adsorbed is reversed depending on the relative pressure, that is, a certain relative pressure. At the high relative pressure side, the first adsorbent shows a larger equilibrium adsorption amount than the second adsorbent, while the second adsorbent has the first adsorbent at the low relative pressure side. There are various types that show a larger equilibrium adsorption amount than the adsorbent.

This reversal is caused by a difference in the pore size of the adsorbents, and the second adsorbent has a higher affinity for the substance to be adsorbed than the first adsorbent. The two adsorbents show a larger equilibrium adsorption amount than the first adsorbent, but on the high relative pressure side, the first adsorbent has a larger number of pores than the second adsorbent (in other words, Large specific surface area)
It is considered that the characteristics of the first adsorbent, such as the first adsorbent, are exhibited, and this causes the first adsorbent to exhibit a larger equilibrium adsorption amount than the second adsorbent.

Focusing on this point, according to the first aspect of the invention, in the case of the first and second adsorbents of the above example, the first adsorbent is the main adsorbent and the second adsorbent is the adsorbent. As an agent,
By adhering the second adsorbent to the inner surface of the pores of the first adsorbent, the first adsorbent (main adsorbent) has a high affinity for the substance to be adsorbed of the second adsorbent (impregnated adsorbent). Is shifted to the lower relative pressure side (for example, the adsorption characteristic of activated carbon is shifted to the lower relative pressure side as shown by the broken line in FIG. 4). By this characteristic shift, the first adsorbent (main adsorbent) is an improved adsorbent that can exhibit the high adsorptivity (large equilibrium adsorption amount) exhibited on the high relative pressure side from the low relative pressure side.

That is, according to the first aspect of the present invention,
Excellent adsorbent that the adsorbent selected as the main adsorbent exhibits the high adsorptivity (large equilibrium adsorption amount) shown on the high relative pressure side from the low relative pressure side and shows high adsorptivity in the low relative pressure range By using this improved adsorbent, in various fields utilizing adsorption, the adsorptivity in a low relative pressure range can be increased, and the efficiency of adsorption can be further improved.

Further, if this improved adsorbent is used as the adsorbent for the refrigerating cycle of an adsorption refrigerator, in the adsorption / evaporation step, even under the condition where the relative pressure is low as described above, high adsorbability and high efficiency can be obtained. Refrigerant vapor can be adsorbed by the adsorbent for the refrigeration cycle, which can increase the refrigerating capacity as compared with conventional adsorption refrigerators.
The required amount of adsorbent can be reduced and the device can be miniaturized.

[2] According to the second aspect of the present invention, the first aspect
In the practice of the described invention, activated carbon is used as the main adsorbent.

That is, as can be seen from FIG. 4, activated carbon shows only a very small amount of equilibrium adsorption in a low relative pressure range, but when the relative pressure is increased, the amount of equilibrium adsorption increases greatly and is larger than other adsorbents. Shows the equilibrium adsorption amount.

Therefore, activated carbon is used as the main adsorbent. On the other hand, the relative pressure causes a reversal of the equilibrium adsorption amount between the activated carbon and the activated carbon. On the relative pressure side, if another appropriate adsorbent exhibiting a larger equilibrium adsorption amount than activated carbon is used as the impregnated adsorbent, and this other adsorbent is impregnated on the inner surface of the pores of the activated carbon, the activated carbon has a high relative pressure. The improved adsorbent can exhibit higher adsorptivity (large equilibrium adsorption amount) than the other adsorbents shown on the side from the side of low relative pressure.

[3] According to the third aspect of the invention, in the first aspect,
Alternatively, in the practice of the invention described in Item 2, silica gel, zeolite, activated alumina, or calcium silicate is used as the adsorbent.

That is, as can be seen from FIG. 4, the adsorbents such as silica gel, zeolite, activated alumina and calcium silicate have a linear function with a limited rate of change even when the relative pressure is increased. Although it only increases, a certain amount of equilibrium adsorption can be obtained even in a low relative pressure range of, for example, 0.4 or less or 0.2 or less.

Accordingly, silica gel, zeolite, activated alumina, or calcium silicate is used as the adsorbent. On the other hand, the relative pressure causes a reversal of the equilibrium adsorption amount between the impregnated adsorbent and the high adsorbent. Shows an equilibrium adsorption amount larger than that of the impregnated adsorbent, but on the low relative pressure side, another appropriate adsorbent exhibiting an equilibrium adsorption amount smaller than that of the impregnated adsorbent is used as the main adsorbent, and By adhering the adsorbent to the inner surface of the pores of the adsorbent, the adsorption characteristics of the other adsorbent can be reduced by a low relative pressure with a high affinity to the target substance indicated by silica gel, zeolite, activated alumina and calcium silicate. The other adsorbent can effectively exhibit the high adsorptivity (large equilibrium adsorption amount) exhibited at the high relative pressure side at the low relative pressure side. It can be an excellent improving adsorbent that.

[4] According to the invention described in claim 4, in claim 2
Alternatively, in the practice of the invention described in 3, the activated carbon is used as the main adsorbent, and the silica gel is used as the impregnated adsorbent.

That is, activated carbon is used as the main adsorbent, and
When silica gel is impregnated on the inner surface of the pores of activated carbon using silica gel as an adsorbent, as can be seen from FIG. 4, silica gel exhibits a relatively large equilibrium adsorption amount as compared with other adsorbents in a low relative pressure region. That the effect of shifting the adsorption characteristics of activated carbon as the main adsorbent to the side of low relative pressure is strong, and that activated carbon as the main adsorbent is inherently higher than other adsorbents in the high relative pressure region. The combination of exhibiting a large equilibrium adsorption amount makes it possible to obtain an improved adsorbent having extremely high adsorptivity in a low relative pressure range.

[5] According to the fifth aspect of the present invention, the fourth aspect
In producing the improved adsorbent of the invention described, a first step of impregnating activated carbon with sodium silicate, a second step of drying, a third step of impregnating sulfuric acid to form a silica sol, and heating The fourth step of gelling, the fifth step of removing sulfuric acid by washing, and the sixth step of drying are performed in that order, and silica gel is attached to the inner surface of the pores of the activated carbon.

In other words, according to this production method, the silica gel as the impregnated adsorbent is thermochemically condensed on the inner surface of the pores of the activated carbon in a form in which the silica gel is thermally aged by the heat treatment in the fourth step. It can be attached to an extremely stable state. Thus, the state after the characteristic shift can be stably maintained, and the high adsorptivity (large equilibrium adsorption amount) exhibited by the activated carbon on the high relative pressure side can be extremely stabilized on the low relative pressure side. A good improved adsorbent which can be exhibited can be obtained. Further, the production method itself is simple, and this improved adsorbent can be produced efficiently and at low cost.

FIG. 6 shows the results of an experiment in which the concentration of the sodium silicate solution impregnated in the activated carbon in the first step was changed and the silica gel impregnation treatment from the first step to the sixth step was performed only once. Show.

[6] According to the invention described in claim 6, in claim 5
In the practice of the invention described, the silica gel impregnation treatment from the first step to the sixth step is repeatedly performed on activated carbon.

That is, by repeating the silica gel impregnation treatment from the first step to the sixth step, the silica gel can be uniformly and densely distributed over the entire inner surface of the activated carbon pores as compared with the one time impregnation treatment. This makes it possible to obtain a better improved adsorbent in which the activated carbon can exhibit the high adsorptivity (large equilibrium adsorption amount) exhibited on the high relative pressure side more effectively on the low relative pressure side. it can.

[7] In the invention according to claim 7, in constituting the adsorption refrigerator, the refrigerant is determined by the relative pressure which is the value of the ratio of the refrigerant vapor pressure to the saturated vapor pressure of the refrigerant around the adsorbent. Of different types of adsorbents whose equilibrium adsorption amount is reversed with respect to the other adsorbents. An adsorbent exhibiting a larger equilibrium adsorption amount than the main adsorbent on the side of the relative pressure is used as the adsorbent, and the improved adsorbent in which the impregnated adsorbent is attached to the inner surface of the pores of the main adsorbent (that is, the claim 1) is used as an adsorbent for a refrigeration cycle.

Then, while adsorbing the refrigerant vapor generated in the evaporator onto the adsorbent for the refrigeration cycle under cooling by the cooling medium, the refrigerant is evaporated by the evaporator, and the heat of vaporization during the evaporation of the refrigerant is obtained. An adsorption / evaporation process that generates cold heat by deprivation, and a desorption refrigerant vapor is desorbed from a refrigeration cycle adsorbent under heating by a driving heat source, and the desorbed refrigerant vapor is condensed in a condenser, and heat is released by the refrigerant condensation. The desorption / condensation step of releasing heat to the application medium is alternately and repeatedly performed.

That is, according to the seventh aspect of the present invention, by using the improved adsorbent according to the first aspect of the present invention as an adsorbent for a refrigeration cycle, the relative pressure in the adsorption / evaporation step is specified to be low. Even under the conditions, the refrigerant vapor can be efficiently adsorbed by the adsorbent for the refrigeration cycle with high adsorptivity, whereby the refrigerating capacity can be effectively increased as compared with the conventional adsorption refrigerator, and The apparatus can be effectively miniaturized by reducing the required amount of the agent.

[8] According to the invention described in claim 8, according to claim 7,
In the practice of the described invention, water is used as the refrigerant, whereas activated carbon is used as the main adsorbent of the adsorbent for the refrigeration cycle.

That is, while water is used as the refrigerant, the improved adsorbent according to the second aspect of the present invention, that is, activated carbon has a higher adsorption of water than the other adsorbents indicated on the high relative pressure side. The improved adsorbent, which can effectively exert the property (see FIG. 4) from the side of low relative pressure, is used for the adsorbent for the refrigeration cycle, thereby taking advantage of the environmental conservation advantage of using water as the refrigerant. However, it is possible to effectively improve the refrigerating capacity of the water refrigerant adsorption refrigerator and reduce the size of the apparatus by reducing the required amount of adsorbent.

[0032]

[9] According to the ninth aspect, in the seventh aspect,
Alternatively, in the practice of the invention described in 8, the water is used as the refrigerant, while silica gel, zeolite, activated alumina, or calcium silicate is used as the adsorbent for the adsorbent for the refrigeration cycle.

That is, while water is used as the refrigerant, the improved adsorbent according to the third aspect of the present invention, that is, silica gel, zeolite, activated alumina and calcium silicate exhibit high affinity for water (FIG. 4). ), The improved adsorbent which the main adsorbent can effectively exhibit the high adsorptivity exhibited at the high relative pressure side at the low relative pressure side is used for the refrigeration cycle adsorbent. Similarly to the invention of claim 8, while utilizing the environmental conservation advantage of using water as the refrigerant, the refrigerating capacity of the water refrigerant adsorption refrigerator is improved, and the size of the apparatus is reduced by reducing the required amount of adsorbent. Can be realized effectively.

[10] In the tenth aspect of the present invention, in the practice of the eighth or ninth aspect, water is used as a refrigerant, whereas activated carbon is used as a main adsorbent of a refrigeration cycle adsorbent, and Silica gel is used as the adsorbent for the adsorbent for the refrigeration cycle.

That is, while water is used as the refrigerant, the improved adsorbent according to the fourth aspect of the present invention, that is, silica gel has a relatively large equilibrium with water in the low relative pressure region as compared with other adsorbents. It indicates the amount of adsorption (see FIG. 4). It has a strong effect of shifting the adsorption characteristics of activated carbon as the main adsorbent to the side of low relative pressure, and shows that activated carbon as the main adsorbent has a high relative The improved adsorbent exhibiting a very high adsorptivity in the low relative pressure range, which is combined with exhibiting a larger equilibrium adsorption amount than other adsorbents in the pressure range (see FIG. 4), is used as the adsorbent for the refrigeration cycle. As a result, it is possible to more effectively realize the improvement of the refrigerating capacity of the water-refrigerant adsorption refrigerator, and the miniaturization of the apparatus by reducing the required amount of the adsorbent.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic configuration of an adsorption refrigerator to which the present invention is applied, 1 is an adsorber in which an adsorbent heat exchanger 2 is installed, and 3 is an interior of a first refrigerant heat exchanger 4. The first evaporator / condenser 5 is a second evaporator / condenser in which the second refrigerant heat exchanger 6 is provided.

The adsorbent heat exchanger 2 is provided with an adsorbent A for a refrigeration cycle. For the adsorber 1, the first evaporator / condenser 3 and the second evaporator / condenser 5 are connected to the refrigerant vapor. The refrigerant vapor path 7 is connected in parallel via a path 7 and is provided with a refrigerant vapor valve 8 for switching a refrigerant vapor flow path. Further, the interior of the adsorber 1, the first evaporator / condenser 3, and the second evaporator / condenser 5 connected by the refrigerant vapor path 7 is reduced to a predetermined pressure by a vacuum pump (not shown) during the operation of the refrigerator. keep.

As the adsorbent A for the refrigeration cycle, as schematically shown in FIG. 3, an improved adsorbent in which an impregnated adsorbent y is attached to the inner surface of the pores of the main adsorbent x is used. The selection of the impregnated adsorbent y depends on the relative pressure p / p ₀ (in other words, the relative humidity%), which is the value of the ratio of the refrigerant vapor pressure p to the saturated vapor pressure p ₀ of the refrigerant R around the adsorbent. A different adsorbent in which the equilibrium adsorption amount q with respect to the refrigerant R is reversed is selected, and among these adsorbents, an adsorbent exhibiting a larger equilibrium adsorption amount q than the other adsorbent on the side of high relative pressure is a main adsorbent x And the main adsorbent x on the side of low relative pressure
Adsorbent with an equilibrium adsorption amount q greater than
There is.

In other words, the high affinity of the adsorbent y for the refrigerant R, which is considered to be the cause of the fact that the impregnated adsorbent y exhibits a larger equilibrium adsorption amount q (that is, high adsorbability) than the main adsorbent x at the lower relative pressure side. With this, the adsorption characteristic of the main adsorbent x is shifted to the lower relative pressure side (for example, the adsorption characteristic of activated carbon is shifted to the lower relative pressure side as shown by the broken line in FIG. 4), and the characteristic shift causes x is an improved adsorbent which can exhibit the high adsorptivity (large equilibrium adsorption amount q) shown on the high relative pressure side from the low relative pressure side. By using this improved adsorbent as the adsorbent A for a refrigeration cycle, even in an operating condition in which the relative pressure p / p ₀ is limited to a low value of, for example, 0.4 or less, in the adsorption / evaporation step described below. The refrigerant vapor can be efficiently adsorbed on the adsorbent A for the refrigeration cycle.

Specifically, while water is used as the refrigerant R to make the adsorption refrigerator excellent in environmental protection, the main adsorbent x contains water at a high relative pressure region as shown in FIG. Activated carbon showing higher adsorptivity (larger equilibrium adsorption amount q) than other adsorbents, and impregnated adsorbent y with water at a low relative pressure range as shown in FIG. Silica gel having a relatively high adsorptivity (in other words, a high affinity for water) is used, thereby effectively improving the adsorptivity in the low relative pressure range due to the characteristic shift as described above.

The refrigerating machine is operated by alternately performing the forward cycle operation and the backward cycle operation. In the forward cycle operation, as shown in FIG. 1, cold water C as a medium to be cooled is supplied to the first refrigerant heat exchanger 4. (For example, cooling water that needs to be cooled from 12 ° C. to about 7 ° C.), while cooling water W (for example, cooling water circulated between the cooling tower and the cooling tower) as a heat dissipation medium in the second refrigerant heat exchanger 6 ). Also, in the return cycle operation, as shown in FIG. 2, contrary to the forward cycle operation, the cooling water W as the heat radiating medium flows through the first refrigerant heat exchanger 4, whereas the second refrigerant heat exchanger 6 Of cold water C as a medium to be cooled.

The contents of the forward cycle operation (see FIG. 1) are as follows.
In a state in which the refrigerant vapor flow between the evaporator / condenser 5 and the adsorber 1 is cut off, and only the refrigerant vapor flow between the first evaporator / condenser 3 and the adsorber 1 is allowed, Cooling water W '(for example, cooling water circulated between the cooling tower) as a cooling medium is circulated through the adsorbent heat exchanger 1, whereby the cooling water W' is used as an adsorption / evaporation step in the forward cycle operation. While adsorbing the refrigerant vapor generated in the first evaporator / condenser 3 on the refrigeration cycle adsorbent A under cooling by the
The refrigerant R is evaporated by the evaporator / condenser 3, and the chilled water C is cooled by the first refrigerant heat exchanger 4 by removing vaporization heat during the evaporation of the refrigerant. That is, the first evaporator / condenser 3 functions as the evaporator EV to generate cold heat.

Thereafter, the operation of the refrigerant vapor valve 8 causes the first
In a state where the refrigerant vapor flow between the evaporator / condenser 3 and the adsorber 1 is shut off, only the refrigerant vapor flow between the second evaporator / condenser 5 and the adsorber 1 is allowed, Hot water H (for example, hot water using waste heat of 80 ° C. or less) as a driving heat source is allowed to flow through the adsorbent heat exchanger 1, and thereby, as a desorption / condensation step in a forward cycle operation, refrigeration under heating with hot water H is performed. The desorbed refrigerant vapor is condensed by the second evaporator / condenser 5 while the adsorbed refrigerant vapor is desorbed from the cycle adsorbent A, and the refrigerant condenses to radiate heat to the cooling water W in the second refrigerant heat exchanger 6. Let it. That is, the second evaporator / condenser 5 is caused to function as the condenser CD to release the exhaust heat.

On the other hand, the content of the return cycle operation (see FIG. 2) is the same as the desorption / condensation step in the forward cycle operation.
First, the flow of the refrigerant vapor between the first evaporator / condenser 3 and the adsorber 1 is shut off, and only the flow of the refrigerant vapor between the second evaporator / condenser 5 and the adsorber 1 is allowed. In this state, the cooling water W ′ as a cooling medium is passed through the adsorbent heat exchanger 1, whereby the adsorbent for the refrigeration cycle is cooled under cooling by the cooling water W ′ as an adsorption / evaporation step in the return cycle operation. A adsorbs the refrigerant vapor generated in the second evaporator / condenser 5 while evaporating the refrigerant R in the second evaporator / condenser 5 and removes the vaporized heat at the time of evaporating the refrigerant. In step 6, the cold water C is cooled. That is, the second evaporator / condenser 5 functions as the evaporator EV to generate cold heat.

Thereafter, by operating the refrigerant vapor valve 8, the refrigerant vapor flow between the second evaporator / condenser 5 and the adsorber 1 is cut off, and the flow between the first evaporator / condenser 3 and the adsorber 1 is interrupted. Adsorbent heat exchanger 1 with only refrigerant vapor flow allowed
Hot water H as a driving heat source is circulated, and as a desorption / condensation step in the return cycle operation, the desorbed refrigerant vapor is desorbed from the adsorbent A for the refrigeration cycle while being heated by the hot water H while being desorbed. The vapor is condensed in the first evaporator / condenser 3, and the refrigerant is condensed to radiate heat to the cooling water W in the first refrigerant heat exchanger 3. That is, the first
The evaporator / condenser 3 functions as a condenser CD to radiate the exhaust heat. After this, the operation returns to the forward cycle operation again.

The method of producing the above-mentioned improved adsorbent (adsorbent A for a refrigeration cycle) using activated carbon as the main adsorbent x and silica gel as the adsorbent y is described below. A method of repeating the silica gel impregnating treatment (see FIG. 5) of the following first to sixth steps to the activated carbon) an appropriate number of times is employed.

First step: Impregnation with sodium silicate solution (for example, aqueous solution) → Second step: Predetermined temperature (for example, 80
C) in a heating atmosphere for a predetermined period of time → third step:
Impregnated with sulfuric acid (for example, 3.9 normal concentration) to form silica sol on the inner surface of the pores of the activated carbon by reaction with sodium silicate. → Fourth step: heating atmosphere at a predetermined temperature (for example, 80 ° C.) for a predetermined time By heating and aging (for example, 24 hours), the silica sol is gelled and the silica gel is thermochemically adhered to the inner surface of the pores of the activated carbon. → Fifth step: Washing with water to remove sulfuric acid. → Sixth step: drying at a predetermined temperature for a predetermined time.

When activated carbon is used as the main adsorbent x, the activated carbon may be an ordinary activated carbon having a specific surface area (m ² / g) of about 800 to 1500, or 20 activated carbon.
Any of super porous activated carbon (so-called super activated carbon) having a large specific surface area (m ² / g) such as 00 to 4000 may be used.

[Another Embodiment] Next, another embodiment will be described. In the embodiment of the present invention, the main adsorbent x and the impregnated adsorbent y are not limited to a combination of activated carbon (including super activated carbon) and silica gel, but have a relative pressure p / p.
Various kinds of adsorbents can be employed as long as the adsorbent is a different kind of adsorbent in which the equilibrium adsorption amount q (adsorbability) for the substance to be adsorbed is reversed depending on the level of ₀ .

The substance to be adsorbed is not limited to water (steam), but various substances can be used as the object to be adsorbed. Further, the improved adsorbent is also used as an adsorbent for a refrigeration cycle of an adsorption refrigerator. However, the present invention is not limited thereto, and can be used in various adsorption application fields such as dehumidification and deodorization.

In the embodiment of the invention described in claim 5, the first
Specific processing conditions such as temperature, pressure, processing time, solution concentration, and used cleaning liquid in each of the sixth to sixth steps are not limited to the example shown in the above-described embodiment, and various changes can be made.

When the silica gel impregnation treatment in the first to sixth steps is repeated a plurality of times, the number of repetitions may be appropriately determined according to the required adsorption characteristics as an improved adsorbent. The number of times of the silica gel impregnation treatment over the process may be only one.

In the embodiment of the present invention, the structure of the adsorbent A in the adsorption refrigerator, the flow structure of the refrigerant vapor, the flow structure of the cooling medium W 'and the driving heat source H, the adsorber 1
The specific device structure such as the container structure of the evaporator EV and the condenser CD can be variously changed.

Further, the cooling medium W ', the driving heat source H, the cooling medium C, and the heat radiating medium W are not limited to water, but various types can be adopted. Further, the refrigerant R is not limited to water. Alternatively, other refrigerants may be used.

Incidentally, reference numerals are written in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings by the entry.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an adsorption refrigerator and an operation state of a forward cycle operation.

FIG. 2 is a diagram showing an operation state of a return cycle operation.

FIG. 3 is a schematic diagram of an improved adsorbent.

FIG. 4 is an isothermal adsorption diagram showing the relationship between the relative pressure of each adsorbent and the equilibrium adsorption amount.

FIG. 5 is a flow sheet of a method for producing an improved adsorbent.

FIG. 6 is an isothermal adsorption diagram showing a shift effect of activated carbon characteristics by silica gel impregnation.

[Explanation of symbols]

p ₀ saturated vapor pressure p vapor pressure x main adsorbent y impregnated adsorbent R refrigerant A adsorbent for refrigeration cycle W 'cooling medium EV evaporator H drive heat source CD condenser W heat dissipation medium

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yasuo Uchikawa 1-1-1 Hama, Amagasaki-shi, Hyogo Prefecture Inside Kubota Research Institute of Technology (72) Inventor Fumio Kimura 1-1-1 Hama, Amagasaki-shi, Hyogo Co., Ltd. Kubota Research and Development Laboratory (72) Inventor Yosuke Takemoto 3-1-3 Nihonbashi Muromachi, Chuo-ku, Tokyo Kubota R & D Planning Dept.

Claims (10)

[Claims] 1. The method of claim 1 wherein the relative pressure (p / p ₀ ), which is the value of the ratio of the vapor pressure (p) of the substance to be adsorbed to the saturated vapor pressure (p ₀ ) of the substance to be adsorbed, around the adsorbent. Using a different type of adsorbent that causes a reversal in the equilibrium adsorption amount for the target substance, of these adsorbents, the adsorbent that shows a larger equilibrium adsorption amount than the other adsorbent on the high relative pressure side is the main adsorbent (x) And an adsorbent exhibiting a larger equilibrium adsorption amount than the main adsorbent (x) on the side of low relative pressure is used as an adsorbent adsorbent (y). An improved adsorbent to which an impregnated adsorbent (y) is impregnated. 2. The improved adsorbent according to claim 1, wherein activated carbon is used as said main adsorbent (x). 3. The improved adsorbent according to claim 1, wherein silica gel, zeolite, activated alumina, or calcium silicate is used as the adsorbent (y). 4. An activated carbon is used as the main adsorbent (x),
The improved adsorbent according to claim 2 or 3, wherein silica gel is used as the adsorbent (y). 5. The method for producing an improved adsorbent according to claim 4, wherein a first step of impregnating the activated carbon with a sodium silicate solution, a second step of drying, and a step of impregnating the sulfuric acid with the silica sol. The third step of forming, the fourth step of gelling the silica sol by heating, the fifth step of removing sulfuric acid by washing, and the sixth step of drying are performed in this order, and the inner surface of the pores of the activated carbon is performed. A method for producing an improved adsorbent by impregnating silica gel with silica gel. 6. The method for producing an improved adsorbent according to claim 5, wherein the silica gel impregnation treatment from the first step to the sixth step is repeatedly performed on the activated carbon. 7. An adsorption refrigerator using the improved adsorbent according to claim 1, wherein a ratio of a refrigerant vapor pressure (p) to a saturated vapor pressure (p ₀ ) of the refrigerant (R) around the adsorbent is obtained. Relative pressure (p / p ₀ )
Of different adsorbents whose equilibrium adsorption amount with respect to the refrigerant (R) is reversed depending on the level of the adsorbent. Among these adsorbents, the adsorbent showing a higher equilibrium adsorption amount than the other adsorbent at the side of high relative pressure is used. An adsorbent, which is a main adsorbent (x) and exhibits an equilibrium adsorption amount larger than that of the main adsorbent (x) on the side of low relative pressure, is an impregnated adsorbent (y). The improved adsorbent having the impregnated adsorbent (y) impregnated on the inner surface of the pores is referred to as a refrigerating cycle adsorbent (A), and the refrigerating cycle adsorbent (A) is cooled under a cooling medium (W ′). An adsorption / evaporation step of evaporating the refrigerant (R) in the evaporator (EV) while adsorbing the refrigerant vapor generated in the evaporator (EV) and generating cold heat by removing vaporization heat in evaporating the refrigerant; Adsorption for the refrigeration cycle under heating by a driving heat source (H) The desorption / condensation step of desorbing the desorbed refrigerant vapor in the condenser (CD) while desorbing the adsorbed refrigerant vapor from (A) and releasing heat to the heat radiation medium (W) by condensing the refrigerant is alternately performed. An adsorption refrigerator configured to be repeatedly implemented. 8. Where water is used for the refrigerant (R),
The adsorption refrigerator according to claim 7, wherein activated carbon is used as the main adsorbent (x) of the adsorbent (A) for the refrigeration cycle. 9. Where water is used as the refrigerant (R),
9. The adsorption refrigerator according to claim 7, wherein silica gel, zeolite, activated alumina, or calcium silicate is used for the adsorbent (y) of the adsorbent (A) for the refrigerating cycle. 10. While water is used as the refrigerant (R), activated carbon is used as the main adsorbent (x) of the refrigeration cycle adsorbent (A), and the refrigeration cycle adsorbent (A) is used. The adsorption refrigerator according to claim 8 or 9, wherein silica gel is used for the adsorbent adsorbent (y)).