JPH10244119A - Adsorption column - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deterioration of performance of a zeolite in packing work by providing a hygroscopic agent layer on a main adsorbent layer in an adsorption equipment formed by packing the zeolite as the main adsorbent layer in a vessel. SOLUTION: The adsorption equipment 2A of a vertical type vessel is provided successively with a hygroscopic agent layer 20 provided with gas supply and discharge passages 5A and 6A and packed with a hygroscopic agent in a hollow part from a lower part, the main adsorbent layer 21 packed with the zeolite and further the hygroscopic agent layer 20' packed with the hygroscopic agent like the hygroscopic agent layer 20. And a weight 23 is laminated with a net 22 on the packed layers. Relating to gaseous oxygen producing device or the like in this way, the gas supply and discharge passage 5A as a gaseous starting material supply port and the gas supply and discharge passage 6A as a product gas discharging port are provided and the moisture in the gaseous starting material supplied from the gas supply and discharging passage 5A is adsorbed in the hygroscopic agent layer 20, a component to be separated is adsorbed and separated in the main adsorbent layer and the gas is finally brought into contact with the hygroscopic agent layer 20' and taken out as the product gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an adsorber using zeolite as a main adsorbent layer for adsorbing a target separated component.

[0002]

2. Description of the Related Art An adsorber according to the present invention is one in which zeolite is packed as a main adsorbent layer for adsorbing a target separation component from a raw material gas, and the adsorption performance of zeolite varies depending on pressure and temperature conditions. It is used in an oxygen gas producing apparatus using a pressure fluctuation adsorption method or a pretreatment apparatus for a cryogenic gas separation apparatus using a temperature fluctuation adsorption method, utilizing the above method.

[0003] Pressure fluctuation adsorption method (PSA method, Pressure
The adsorber used in the oxygen gas producing apparatus by the Swing Adsorption method is provided for separating nitrogen (separated components) and has a main adsorbent layer filled with zeolite that selectively adsorbs nitrogen. . The PSA method uses a pressure change to bring a raw material gas such as air containing nitrogen in addition to oxygen into contact with the main adsorbent layer under a pressure condition (usually a pressurized state) in which nitrogen is easily adsorbed. Nitrogen is adsorbed on the main adsorbent layer to produce a high-concentration oxygen gas, and then the separated components adsorbed on the main adsorbent layer are desorbed under a pressure condition (usually reduced pressure) under which nitrogen is easily desorbed. Regeneration of the main adsorbent layer is repeated. Conventional zeolites of this type include Ca-A type, Na-X type and Ca-type.
Zeolite such as -X type is used.

[0004] Temperature fluctuation adsorption method (TSA method, Temperat
The adsorber used in the pretreatment device of the cryogenic gas separation device using ure-swing adsorption method is provided to selectively adsorb and separate water and carbon dioxide (separated components) in the raw material gas. And has a moisture absorbent layer filled with activated alumina and silica gel selectively adsorbing moisture and carbon dioxide, and a main adsorbent layer filled with zeolite. That is, in cryogenic gas separation, in which a raw material gas such as air or natural gas is cooled, compressed and liquefied, and then distilled to separate each component, the raw material gas such as moisture and carbon dioxide gas is used as a pretreatment. The pretreatment for removing the components that become solid under the liquefaction condition is performed. For this reason, moisture,
An adsorber capable of separating and removing carbon dioxide gas is used. TSA
The method makes use of temperature changes to bring the raw material gas into contact with this adsorbent layer under the temperature conditions where moisture and carbon dioxide gas are easily adsorbed. Respectively, to remove separated components, and then, under a temperature condition at which moisture and carbon dioxide gas are easily desorbed, desorb the moisture adsorbed on the desiccant layer and the carbon dioxide gas adsorbed on the main adsorbent layer to remove the desiccant. The regeneration of the layer and the main adsorbent layer is repeated. As this type of zeolite, a zeolite of Na-X type, Ca-A type, or the like has been conventionally used.

FIG. 5 shows an example of the structure of a conventional adsorber of this type, which uses a vertical container whose height is larger than its width. The adsorber 2D has a desiccant layer 20 filled with a desiccant in order from the lower side of a hollow substantially cylindrical container, and a main adsorption filled with a zeolite that selectively adsorbs separation components such as nitrogen and carbon dioxide. Agent layer 2
1, and a filling layer is formed by the moisture absorbent layer 20 and the main adsorbent layer 21. Weights 23 such as ceramic balls are stacked on the filling layer via a net 22 made of metal or the like. The weight 23 is provided to prevent the main adsorbent layer 21 from flowing when the gas passes through the adsorber 2D. Also,
The net 22 is provided for separating the adsorbent layer 21 from the weight 23.

[0006] In this adsorber 2D, the raw material gas is supplied from a gas supply lead-out channel 5D provided at the lower part, contacts the hygroscopic agent layer 20, and removes moisture.
1, the separated component is adsorbed and removed, and is taken out as a product gas from a gas supply lead-out passage 6D provided at an upper portion. In the adsorber 2D, first, a desiccant is charged and filled from a manhole or the like (not shown) on the upper side of the adsorber 2D to form a desiccant layer 20, on which zeolite is charged and filled. The adsorbent layer 21 can be formed by further laying a net 22 and stacking a weight 23 thereon. Conventionally, in this type of adsorber, the gas supply and outlet path 5D provided at the lower part of the container is used as a raw material gas supply port, and the gas supply and outlet path 6D provided at the upper part of the container is used as a product gas outlet. In general, the main adsorbent layer 21 is the uppermost layer of the packed layer, and the net 22 is laid thereon.

[0007]

By the way, it is well known that zeolite easily adsorbs moisture, and it is known that adsorbing moisture deteriorates the adsorption performance for separation components such as nitrogen. . For example, in this regard, literature (Hirooka, Saito Ceramics 20 NO.3 P1
75- (1985)), the following is described for a typical zeolite, molecular sieves.

"Effect of adsorbed water" The negatively charged portion of water strongly adsorbs to positively charged metal ions of molecular sieves. Therefore, it has been used as a desiccant for a long time. The adsorbed water in molecular sieves is nitrogen. , Lowers the equilibrium adsorption of oxygen, and at the same time, inhibits the diffusion rates of nitrogen and oxygen.
The oxygen production process must be a process that does not accumulate moisture. When filling molecular sieves into the adsorber, it is necessary to select a sunny day and make efforts to fill in as short a time as possible. "

As shown in this document, although the effect of moisture on the adsorption performance of zeolite is widely recognized, the countermeasure is to minimize the filling time of zeolite as described above. However, it was reluctant to fill zeolite in fine weather as much as possible.

FIG. 6 shows "the latest applied technology of zeolite".
(CMC, 1986, P-135), the effect of the residual moisture of the molecular sieves (zeolite) of the two types of adsorbents A and B in the PSA-type oxygen gas production equipment was investigated. (Oxygen yield) as a graph. FIG. 7 shows the rate of moisture absorption of the zeolite, and is a graph of the change in the water content of the zeolite with time when the zeolite is left in the air.

FIG. 6 shows that the oxygen recovery rate of both the adsorbents A and B sharply decreases in proportion to the increase in the residual water content. In FIG. 7,
After about 20 minutes, the water content becomes about 3%, and after 50 minutes, the water content exceeds 6%. That is, when associating the graph shown in FIG. 6 with the graph shown in FIG. 7, in the oxygen gas producing apparatus using zeolite which has been left in the atmosphere for about 1 hour, the oxygen recovery rate is greatly reduced, and almost no It is expected that it will no longer have the property.

By the way, in the adsorber 2D shown in FIG. 5, the filling of the desiccant layer 20 and the filling of the main adsorbent layer 21 are performed as follows.
Since the moisture absorbent and the zeolite may be directly charged into the adsorber 2D in order from a drum or a flexible container which is a bag impervious to moisture, the process is performed very quickly and the process can be completed in a short time. On the other hand, the laying of the net 22 takes a long time, and sometimes takes about one hour. This is because the weight 23 and the main adsorbent layer 21 need to be sufficiently separated by the net 22 so as not to be mixed. At this time, even if the main adsorbent layer 21 sinks during use of the adsorber 2D, the size of the net 22 must be adjusted so that the net 22 always covers the upper surface of the main adsorbent layer 21. 21 must be made larger than the area of the upper surface, and the periphery of the net 22 must be formed along the inner wall of the adsorber 2D without any gap. Therefore, during this operation, the zeolite above the main adsorbent layer 21 may absorb moisture in the atmosphere and deteriorate, and the adsorption performance may be lost.

As a countermeasure, there has been proposed a method in which the amount of the main adsorbent layer 21 (zeolite) is set to a relatively large amount in order to maintain the required adsorption performance in anticipation of the loss of the adsorption performance. . However, according to this method, although the zeolite used for the main adsorbent layer 21 is generally expensive, it is necessary to use more zeolite than the theoretical amount of zeolite that satisfies the required adsorption amount of the separated component. Therefore, it is a major cause of cost increase.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an adsorber using zeolite as a main adsorbent layer, which can prevent performance degradation of zeolite during a filling operation. It is another object of the present invention to provide an adsorber capable of efficiently performing treatment using zeolite in an amount close to the theoretical amount of zeolite.

[0015]

In order to solve the above problems, the present invention proposes the following adsorber.
Claim 1 is an adsorber in which a container is filled with zeolite as a main adsorbent layer, wherein a desiccant layer is provided on the main adsorbent layer.
Claim 2 is that the container is filled with zeolite as a main adsorbent layer, and a raw material gas supply port is provided at a lower portion of the container,
An adsorber provided with a product gas outlet at an upper portion of the container, wherein an adsorbent layer is provided on the main adsorbent layer. Claim 3 is an adsorber in which a container is filled with zeolite as a main adsorbent layer, a raw material gas supply port is provided at an upper portion of the container, and a product gas outlet is provided at a lower portion of the container. An adsorber characterized in that a moisture absorbent layer is provided on the main adsorbent layer. Claim 4 is an adsorber in which zeolite is filled in a container as a main adsorbent layer, and a raw material gas supply port and a product gas outlet are provided at a lower portion of the container. An adsorber characterized in that a moisture absorbent layer is provided thereon. Claim 5 is the adsorber according to any one of claims 1 to 4, wherein the desiccant layer contains at least one selected from silica gel, activated alumina, and zeolite. Claim 6 is the adsorber according to any one of claims 1 to 5, wherein the filling height of the moisture absorbent layer is 50 to 300 mm.
Claim 7 is the adsorber according to any one of claims 1 to 6, wherein the container is a vertical container. Claim 8 is the adsorber according to any one of claims 1 to 6, wherein the container is a horizontal container.

[0016]

FIG. 1 shows a first example of the structure of the adsorber of the present invention. The same components as those shown in FIG. 5 are denoted by the same reference numerals and are simplified. . The adsorber 2A is formed of a hollow and substantially cylindrical container whose height is larger than its width. Such a container is called a vertical container. The lower part of the adsorber 2A is provided with a gas supply lead-out path 5A, and the upper part is provided with a gas supply lead-out path 6A. One of the gas supply and outlet paths 5A and 6A serves as a source gas supply port, and the other serves as a product gas outlet. Further, in the hollow portion of the adsorber 2A, in order from the lower side, a desiccant layer 20 filled with a desiccant, a main adsorbent layer filled with zeolite that selectively adsorbs separation components such as nitrogen and carbon dioxide gas. 21, a hygroscopic layer 20 ′ filled with a hygroscopic agent is provided in the same manner as the hygroscopic layer 20;
A filling layer is formed from the moisture absorbent layer 20, the adsorbent layer 21, and the moisture absorbent layer 20 '. Then, a weight 23 such as a ceramic ball is laminated on the filling layer via a net 22.

In a PSA type oxygen gas producing apparatus, etc.,
Normally, the lower gas supply outlet 5A is used as a source gas supply port, and the upper gas supply outlet 6A is used as a product gas outlet. In this case, in the raw material gas supplied from the gas supply / lead-out passage 5A, after moisture is adsorbed by the desiccant layer 20, separated components are adsorbed and separated by the main adsorbent layer 21, and finally, the desiccant layer 20 ' , And is taken out as a product gas from the gas supply and outlet path 6A. Alternatively, the source gas may be supplied from the gas supply lead-out path 6A. In this case, in order to adsorb and remove moisture from the raw material gas supplied from the gas supply lead-out passage 6A, the hygroscopic layer 20 'is filled in an amount equivalent to the hygroscopic layer 20 when the raw material gas is supplied from below. Therefore, the moisture absorbent layer 20 can be omitted. At this time, in the raw material gas supplied from the gas supply and outlet path 6A, after moisture is adsorbed by the desiccant layer 20 ', the separated components are adsorbed and separated by the main adsorbent layer 21. 20 and is taken out as product gas from the gas supply and outlet channel 5A.

The filling operation is performed as follows. First, a hygroscopic agent is charged and filled from the upper side of the adsorber 2A to form a hygroscopic agent layer 20, on which zeolite is charged and filled to form a main adsorbent layer 21. The moisture absorbent is injected and filled from above the adsorber 2A to form a moisture absorbent layer 20 '. Next, a net 22 is laid, and a weight 23 is laminated thereon.

Here, the moisture absorbent layer 20, the main absorbent layer 21,
Since the work of filling the moisture absorbent layer 20 'can be performed promptly, the zeolite filled in the main adsorbent layer 21 is immediately covered with the moisture absorbent layer 20'. Therefore, while the net 22 is laid on the moisture absorbent layer 20 ', the zeolite (main adsorbent layer 21) is protected by the moisture absorbent layer 20' and does not come into contact with the atmosphere, so that the net 22 is laid in the conventional manner. Thus, there is no possibility that the performance is degraded by adsorbing moisture in the air while the weight 23 is being laminated. For this reason,
In this adsorber 2A, it is possible to sufficiently extract most of the adsorption performance of the zeolite filled as the main adsorbent layer 21, and it is possible to reduce the amount of zeolite used. Generally, zeolite used for the main adsorbent layer 21 is expensive, and the desiccant filled in the desiccant layers 20, 20 'is inexpensive, so that the cost can be reduced.

As the desiccant constituting the desiccant layer 20 and the desiccant layer 20 ', silica gel, activated alumina or the like can be preferably used alone or in combination. Alternatively, K-, which has been conventionally used exclusively for moisture adsorption,
A-type and Na-A-type zeolites can also be used. These are inexpensive and economical. Or C
a-A type, Na-X type, Ca-X type zeolite other than dedicated to moisture adsorption can be used if it is inexpensive,
In such a zeolite, a zeolite in which Ca or Na is ion-exchanged with another ion may be used.

The filling height of the moisture absorbent layer 20 'is 50 to 50.
300 mm is preferred. If it is less than 50 mm, the main adsorbent layer 21 cannot be sufficiently covered while the net 22 is laid,
When the distance exceeds mm, the purpose of protecting the main adsorbent layer 21 is achieved, but the amount of the hygroscopic agent becomes excessive and the cost reduction effect is reduced. However, when the source gas is supplied from the gas supply lead-out passage 6A (upper side), the filling height may exceed 300 mm so as to secure a necessary amount for absorbing moisture in the source gas.

The structure of the packed bed is as follows.
It suffices that the moisture absorbent layer 20 ′ is provided on 1. The moisture absorbent layer 20 ′ may be in contact with the main adsorbent layer 21,
You don't have to. However, it is preferable that the moisture absorbent layer 20 ′ be the uppermost layer of the packed layer, because moisture remaining in the upper space of the adsorber 2A can be removed after the filling operation or during or after the actual gas processing. Main adsorbent layer 21
The volume is appropriately set according to the performance of zeolite, the amount of separated components in the raw material gas, and the like. The moisture absorbent layer 20 secures a required volume for absorbing moisture in the raw material gas. This moisture absorbent layer 20 may be provided below the adsorbent layer 21, but by providing it at the bottom of the packed layer,
At the beginning of the filling operation, the adsorber 2A is
The water remaining in the (vessel) can be reduced, and the performance deterioration of the zeolite when the main adsorbent layer 21 is subsequently filled can be further reduced. In addition, after the filling operation or during or after the actual gas treatment, the adsorber 2A This is preferable because water remaining in the lower space of the substrate can be removed. Further, in the case where the material gas is fixed so as to be supplied from the upper gas supply lead-out passage 6A, the configuration may be such that the moisture absorbent layer 20 is not provided.

FIG. 2 is a schematic diagram showing an example of a PSA type oxygen gas producing apparatus using this type of adsorber. This oxygen gas producing apparatus has the same configuration as the blower 1 for supplying the raw material gas and the adsorber 2A, and includes a main adsorbent layer 21 filled with zeolite for selectively adsorbing nitrogen. A vacuum pump 4 for desorbing nitrogen adsorbed on the main adsorbent layer 21 and regenerating the main adsorbent layer 21; It is schematically composed of

In the production process of the high-concentration oxygen gas (product gas), first, nitrogen in the raw material gas is adsorbed and separated by the main adsorbent layer 21 in the adsorber 2A, and is separated into high-concentration oxygen gas. A regeneration process for desorbing nitrogen adsorbed on the main adsorbent layer 21 by depressurizing the interior of the adsorber 2A to regenerate the main adsorbent layer 21, and without pressure fluctuation when moving from the regeneration process to the adsorption process. In order to make a transition, a charging step of flowing a part of the high-concentration oxygen gas from above the adsorber 2A to pressurize the inside of the adsorber 2A is performed. In this oxygen gas production apparatus, the three steps are performed in parallel in any of the adsorbers 2a, 2b, and 2c, so that the high-concentration oxygen gas is continuously produced.

Hereinafter, the adsorber 2a operates in the adsorbing step,
Will be described together with the operation when the pressure step is in the pressure step and the adsorber 2c is in the regeneration step. First, switching valve 5a
Is connected to the blower 1 and the adsorber 2 via the gas supply outlet 5a '.
a to be connected to the switching valve 6a.
Is switched so as to connect the adsorber 2a and the oxygen compressor 3 via the gas supply lead-out passage 6a '. A control valve 7 is provided in the middle of the gas supply lead-out passage 6a 'to control the supply amount of the high-concentration oxygen gas to the oxygen compressor 3. At the same time, the switching valve 9b is switched via the return flow path 9b 'to connect the branch path 8 branched from the middle of the gas supply lead-out path 6a' to the adsorber 2b. And the vacuum pump 4 and the adsorber 2c are connected to each other via the exhaust path 10c '.

Next, the gas supply and outlet path 5 from the blower 1
The source gas is supplied to the adsorber 2a in a pressurized state via a ′. Then, moisture in the source gas is adsorbed by the desiccant layer 20, and nitrogen in the source gas is adsorbed by the main adsorbent layer 21 to produce a high-concentration oxygen gas. Then, the high-concentration oxygen gas is sent out to a gas supply lead-out passage 6a 'connected to the upper part of the adsorber 2a, supplied to the oxygen compressor 3, and raised to a desired pressure, and then supplied to the consumer (adsorption). Process). At this time, a part of the high-concentration oxygen gas flowing through the gas supply / extraction passage 6a 'is supplied from the upper part of the adsorber 2b through the branch passage 8 and the return flow passage 9b'. The main adsorbent layer 21 is pressurized (pressure step). On the other hand, when the vacuum pump 4 is operated, the pressure in the adsorber 2c is reduced, and the main adsorbent layer 2 in the adsorber 2c is depressurized.
The nitrogen adsorbed on 1 is desorbed and exhausted through an exhaust passage 10c '. Thus, the main adsorbent layer 21 is regenerated (regeneration step).

Hereinafter, switching valves 5a, 5b, 5c, switching valves 6a, 6b, 6c, switching valves 9a, 9b, 9
c, by appropriately switching the switching valves 10a, 10b, and 10c, the three steps are performed in parallel in the three adsorbers 2a, 2b, and 2c, and a high-concentration oxygen gas is continuously produced.

FIG. 3 shows a second example of the adsorber of the present invention. The container used in the adsorber B has a width dimension larger than a height dimension. Such a thing is called a horizontal container. Adsorbers using horizontal vessels are suitable for treating large volumes of gas. This adsorber 2B
Are provided with two gas supply and outlet paths 5B and 5B at the lower part, and two gas supply and outlet paths 6B and 6B are provided at the upper part at positions symmetrical to the gas supply and outlet paths 5B and 5B.

In the hollow portion of the adsorber 2B, in order from the lower side, a desiccant layer 30, a main adsorbent layer 31, and a desiccant layer 30 '.
, And a weight 33 such as a ceramic ball is stacked on the metal layer 32 via a net 32. The moisture absorbent layer 30, the main absorbent layer 31, the moisture absorbent layer 30 ', the net 32, and the weight 33 are formed by the moisture absorbent layer 2 in the adsorber 2A shown in FIG.
0, main adsorbent layer 21, moisture absorbent layer 20 ', net 22, weight 2
3 respectively. The gas supply / discharge paths 5B, 5B and the gas supply / discharge paths 6B, 6B correspond to the gas supply / discharge paths 5A and 6A shown in FIG. 1, respectively. When processing is performed using the adsorber 2B, the raw material gas is supplied from one of the gas supply and outlet paths 5B and 5B or the gas supply and outlet paths 6B and 6B, and the product gas is extracted from the other.

Since the main adsorbent layer 31 is sandwiched between the hygroscopic layer 30 and the hygroscopic layer 30 'in this adsorber 2B, as in the adsorber 2A shown in FIG. Regardless of the source gas supplied from either the supply outlet channel 5B, 5B or the gas supply outlet channel 6B, 6B, before the moisture in the source gas contacts the main adsorbent layer 31, the moisture absorbent layer 30 or the moisture absorbent layer 30 'is contacted and adsorbed. In the case where the source gas is fixed so as to be supplied from the gas supply lead-out passages 6B, 6B, a configuration in which the moisture absorbent layer 30 is not provided may be adopted. The filling operation is also performed by the adsorber
The operation is performed through a manhole (not shown) provided at the upper portion, etc., but at this time, the adsorbent layer 31 (zeolite) is protected by the water absorbing agent layer 30 ′, and the moisture in the atmosphere is removed during the filling operation. There is no possibility that the performance is deteriorated due to adsorption.

FIG. 4 shows a third example of the structure of the adsorber of the present invention. This adsorber 2C has a vertical container whose height is larger than its width, and performs both supply of raw material gas and removal of product gas from below. This can improve the structural strength and the durability, and is suitable for the TSA method in which heating and cooling are repeated. In the hollow portion of the adsorber 2C, a moisture absorbent layer 40, a main absorbent layer 41, and a moisture absorbent layer 40 'are provided in this order from the lower side, and a weight such as a ceramic ball is placed thereon via a net 42. 43 are stacked. These moisture absorbent layers 40,
Main adsorbent layer 41, moisture absorbent layer 40 ', net 42, weight 43
Correspond to the moisture absorbent layer 20, the main absorbent layer 21, the moisture absorbent layer 20 ', the net 22, and the weight 23 in the adsorber 2A shown in FIG.

A major feature of the adsorber 2C is that a gas supply and outlet path 5C and a gas supply and outlet path 6C are provided at the lower part of the container. The gas supply lead-out path 5C passes through the moisture absorbent layer 40, the main adsorbent layer 41, and the moisture absorbent layer 40 ',
One end protrudes from the lower part of the container, and the other end is open to an upper space inside the adsorber 2C. Gas supply outlet 6
C is provided at an interval from an outer peripheral portion of a portion of the gas supply / output passage 5C protruding from the lower part of the container, and has a cross section formed of a pipe concentric with the gas supply / output passage 5C. One end of the gas supply / output channel 6C is connected to the lower part of the container of the adsorber 2C, and the other end is connected to the gas supply / output channel 5C via a donut-shaped bottom portion 46a.
In addition to being fixed and sealed to the middle of the outer peripheral wall, a lateral opening 46 at an appropriate portion below the gas supply / output passage 6C is provided.
Open at b.

In the adsorber 2C, the gas supply and outlet path 5
When C is used as the source gas supply port, the gas supply lead-out path 5
C, the raw material gas having reached the upper space of the adsorber 2C flows from the upper space to the hygroscopic layer 40 ′ and the main adsorbent layer 4
1. The gas comes into contact with the moisture absorbent layer 40 and is taken out of the opening 46a as a product gas through the gas supply / lead-out passage 46. In this case, a configuration in which the moisture absorbent layer 40 is not provided may be adopted. When the gas supply and outlet path 6C is used as a source gas supply port, the source gas contacts the hygroscopic layer 40, the main adsorbent layer 41, and the hygroscopic layer 40 'in this order, and reaches the upper space of the adsorber 2C. After that, the gas is taken out as a product gas through the gas supply and outlet channel 5C. Note that the gas supply and outlet paths 5C and 6C may be provided so that the cross section is concentric as described above,
A pipe-shaped thing may be arranged in parallel below the adsorber 2C. Further, in the adsorber using a horizontal container as shown in FIG. 3, it is possible to adopt a configuration in which both the supply of the source gas and the extraction of the product gas are performed from below. The filling operation is performed in the above-described adsorption tower 2
A and 2B are performed in the same manner.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments. First, the common conditions are shown below. Using the adsorber shown in FIG. 1 or FIG. 5 and the oxygen gas producing apparatus of the PSA type shown in FIG. 2, the concentration of the high-concentration oxygen gas generated is kept constant, and the high-concentration oxygen gas is supplied under the following conditions. Manufactured. At this time, activated alumina was used as the moisture absorbent,
The Ca-A type was used as the main adsorbent (zeolite).

<Conditions for producing high-concentration oxygen gas> Adsorption process pressure (source gas supply pressure) 0.1 kg / cm ² G Regeneration process pressure 250 torr Source gas (air) temperature 25 ° C. Cycle time 60 sec (Adsorption process to charging process— Regeneration process time) Oxygen concentration in high concentration oxygen gas 93%

The structure of the packed bed of the adsorber was as follows. <Embodiments 1 to 3> In the embodiment, the adsorber 2A shown in FIG. 1 was used, the filling height of the desiccant layer 20 and the main adsorbent layer 21 was fixed at 30 cm and 150 cm, respectively,
0 'filling height is 50 mm (Example 1), 150 mm
(Example 2) For the cases of 300 mm (Example 3), after each filling operation, after leaving for 1 hour without shutting off the external air, a high-concentration oxygen gas was produced. Table 1 shows the results.

<Comparative Examples 1-2> (Comparative Example 1) An experiment was performed using the adsorber 2D shown in FIG. The filling heights of the moisture absorbent layer 20 and the main adsorbent layer 21 were set to 30 cm and 150 cm, respectively. At this time, it took one hour to stack the net 22 and the weight 23 (ceramic ball), and as a result, the main adsorbent layer 21 (zeolite) was exposed to air for one hour. (Comparative Example 2) An experiment was performed in the same manner as in Comparative Example 1 except that the net 22 was not laid. In this case, since the net 22 was not laid, the filling operation time was short, and the external air was shut off immediately after the weight 23 was stacked on the main adsorbent layer 21 immediately. Table 1 shows the results.

[0038]

[Table 1]

As shown in Table 1, when producing a high-concentration oxygen gas having a similar concentration, a comparison between the embodiment according to the present invention and Comparative Example 1 shows that the amount of the high-concentration oxygen gas generated per hour in the embodiment is It was confirmed that the performance of the zeolite hardly deteriorated during the filling operation. Further, in Comparative Example 2, although the amount of generated oxygen was almost the same as that of Example, observation was made after the experiment. As a result, a portion where ceramic balls and zeolite were mixed was confirmed.

[0040]

According to the adsorber of the present invention, the following effects can be obtained. 2. The adsorber according to claim 1, wherein the container is filled with zeolite as a main adsorbent layer, wherein a desiccant layer is provided on the main adsorbent layer. Therefore, even if it takes time to lay a net or the like laid above the moisture absorbent layer, the zeolite is protected by the moisture absorbent layer and is not deteriorated by atmospheric moisture. . For this reason, it is not necessary to perform extra filling in anticipation of the deterioration of the zeolite, and the amount of zeolite used can be reduced. Generally, the zeolite filled in the main adsorbent layer is expensive, and the hygroscopic agent charged in the hygroscopic layer is inexpensive, so that the cost can be reduced. Claim 2,
Reference numerals 3 and 4 denote one in which one of a raw material gas supply port and a product gas outlet is provided in a lower portion of the container, and the other is provided in an upper portion of the container, or both are provided in a lower portion of the container. Things. These can be selected according to the purpose. For example, those in which the raw material gas supply port is provided at the lower part and the product gas outlet is provided at the upper part are general PS
The present invention can be applied to an A type oxygen gas production apparatus and the like. One in which both the raw material gas supply port and the product gas outlet are provided at the bottom is suitable for the TSA method. Claim 5 is the adsorber according to any one of Claims 1 to 4, wherein the desiccant layer contains at least one selected from silica gel, activated alumina, and zeolite. The cost can be reduced by using the hygroscopic agent. According to a sixth aspect of the present invention, the filling height of the moisture absorbent layer is 50.
Since it is the adsorber according to any one of claims 1 to 5, the protective effect of the moisture absorbent layer on the main adsorbent layer is sufficiently obtained. Claims 7 and 8 are characterized in that a vertical container or a horizontal container is used as the container.
6, the adsorber according to any one of the above, depending on the gas processing amount, depending on the purpose, such as a vertical container for a relatively small amount of processing, a horizontal container for a relatively large amount of processing. it can.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a structure of an adsorber using a vertical container.

FIG. 2 is a schematic view showing an example of a PSA type oxygen gas producing apparatus.

FIG. 3 is a cross-sectional view showing an example of a structure of an adsorber using a horizontal container.

FIG. 4 is a cross-sectional view showing an example of the structure of an adsorber using a vertical container and having both a raw material gas supply port and a product gas outlet at the bottom.

FIG. 5 is a sectional view showing an example of the structure of a conventional adsorber.

FIG. 6 shows a relationship between residual moisture and oxygen recovery rate (oxygen yield) showing the influence of residual moisture of molecular sieves (zeolite) of two types of adsorbents A and B in a pressure fluctuation adsorption type oxygen gas production apparatus. It is a graph of.

FIG. 7 is a graph of a change in the water content of the zeolite with time when the zeolite is left in the air.

[Explanation of symbols]

2A, 2B, 2C ... adsorber, 20, 30, 40 ... hygroscopic layer, 20 ', 30', 40 '... hygroscopic layer, 21, 31, ...
41: main adsorbent layer, 5A, 5B, 5C: gas supply and outlet path, 6A, 6B, 6C: gas supply and outlet path

Claims (8)

[Claims] 1. An adsorber in which a container is filled with zeolite as a main adsorbent layer, wherein a desiccant layer is provided on the main adsorbent layer. 2. An adsorber comprising a container filled with zeolite as a main adsorbent layer, a raw material gas supply port provided at a lower portion of the container, and a product gas outlet provided at an upper portion of the container. An adsorber, wherein a moisture absorbent layer is provided on the main adsorbent layer. 3. An adsorber comprising a container filled with zeolite as a main adsorbent layer, a raw material gas supply port provided at an upper portion of the container, and a product gas outlet provided at a lower portion of the container. An adsorber, wherein a moisture absorbent layer is provided on the main adsorbent layer. 4. An adsorber in which zeolite is filled in a container as a main adsorbent layer, and a source gas supply port and a product gas outlet are provided at a lower portion of the container, wherein the main adsorbent layer is An adsorber comprising a moisture absorbent layer provided thereon. 5. The adsorber according to claim 1, wherein the desiccant layer contains at least one selected from silica gel, activated alumina, and zeolite. 6. The filling height of the moisture absorbent layer is 50 to 300.
The adsorber according to any one of claims 1 to 5, wherein the diameter is mm. 7. The adsorber according to claim 1, wherein the container is a vertical container. 8. The adsorber according to claim 1, wherein the container is a horizontal container.