JP7122191B2 - Gas separation device, gas separation method, nitrogen-enriched gas production device, and nitrogen-enriched gas production method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a gas separation device, a gas separation method, a nitrogen-enriched gas production device, and a nitrogen-enriched gas production method.

BACKGROUND ART In gas separation by a pressure swing adsorption (PSA) method, a gas separation method using a vacuum pump for desorbing a component adsorbed on an adsorbent is known (Patent Document 1).
On the other hand, there is known a method of using an ejector instead of a vacuum pump when desorbing a component adsorbed on an adsorbent from the adsorbent (Patent Document 2).

JP-A-2002-28429 JP-A-1-184015

However, since the vacuum pump has a drive unit, the gas separation method described in Patent Document 1 has problems such as an increase in the failure of equipment such as the vacuum pump, an increase in maintenance costs, and an increase in the equipment area. .
In the mixed gas separation method described in Patent Literature 2, part of the air pressurized by the compressor is always supplied to the ejector, so that the inside of the adsorption bed container is reduced to a pressure lower than the atmospheric pressure. Therefore, it is necessary to secure a sufficient amount of compressed air to be supplied to the ejector, and it is necessary to increase the amount of raw air to be supplied to the compressor. As described above, the mixed gas separation method described in Patent Document 2 has problems such as an increase in the size of the compressor and an increase in the power consumption of the compressor.

On the other hand, in the mixed gas separation method described in Patent Document 2, when it is attempted to intermittently supply pressurized air to the ejector for the purpose of solving problems such as an increase in the size of the compressor, excessive pressure is applied to the compressor. A load is applied, and there is a possibility that it may cause the failure of the compressor.

An object of the present invention is to provide a gas separation apparatus capable of suppressing an increase in the size of the compressor and an increase in the power consumption of the compressor while suppressing equipment failure, maintenance costs, and an increase in the installation area.

In order to solve the above problems, the present invention has the following configuration.
[1] A gas separation device for separating the first component and the second component from a raw material gas containing the first component and the second component, the compressor compressing the raw material gas; a plurality of adsorption tanks into which a portion of the compressed raw material gas is introduced and filled with an adsorbent that adsorbs the first component in the raw material gas; each of the plurality of adsorption tanks and the compressor; one or more branch pipes branching from the supply pipe; one or more compressed source gas tanks provided in the branch pipes for storing the remainder of the compressed source gas; an aspirator provided in the branch pipe on the secondary side of the source gas tank; and a suction pipe connecting the aspirator and each of the plurality of adsorption tanks, wherein the aspirator serves as a first inlet port. A gas having a second inlet and an outlet, wherein the first inlet and the outlet are arranged along the branch pipe, and the second inlet is connected to the suction pipe separation device.
[2] Using a first adsorption tank filled with an adsorbent, a second adsorption tank filled with the adsorbent, and a compressor, from a raw material gas containing a first component and a second component In the gas separation method for separating the first component and the second component, the compressed raw material gas is introduced into the first adsorption tank to pressurize the inside of the first adsorption tank. a pressurized adsorption step of adsorbing the first component in the raw material gas onto the adsorbent in the first adsorption tank to separate the first component from the second component; a first pressure equalizing step of introducing gas remaining in the first adsorption tank after the pressure adsorption step into the second adsorption tank to pressurize the inside of the second adsorption tank; introduced the raw material gas into the second adsorption tank to adsorb the first component in the raw material gas to the adsorbent in the second adsorption tank, and a reduced pressure regeneration step of reducing the pressure inside the first adsorption tank to desorb the first component from the adsorbent in the first adsorption tank to regenerate the adsorbent in the first adsorption tank; a second pressure equalizing step of introducing gas remaining in the second adsorption tank after the step into the first adsorption tank to pressurize the inside of the first adsorption tank; In either one or both of the first pressure equalizing step and the second pressure equalizing step, the compressed raw material gas is stored in a compressed raw material gas tank arranged on the secondary side of the compressor, and In the reduced-pressure regeneration step, the compressed raw material gas stored in the compressed raw material gas tank is introduced into an aspirator arranged on the secondary side of the compressed raw material gas tank, whereby the aspirator and the first The inside of the first adsorption tank is further depressurized via a suction pipe connecting the first adsorption tank and the second adsorption tank, respectively. The gas separation method further reduces the pressure in the second adsorption tank through the suction pipe by introducing the compressed raw material gas into the suction device.
[3] A nitrogen-enriched gas production apparatus for producing nitrogen-enriched gas from feed air containing nitrogen gas, wherein a compressor for compressing the feed air and a part of the compressed feed air are introduced, a plurality of adsorption tanks filled with an adsorbent that adsorbs components other than nitrogen gas in the feed air; supply pipes connecting each of the plurality of adsorption tanks and the compressor; and branches branching from the supply pipes. one or more branch pipes; one or more compressed raw air tanks that are provided in the branch pipes and store the remainder of the compressed raw air; and are provided in the branch pipes on the secondary side of the compressed raw air tanks. and a suction pipe connecting the aspirator and each of the plurality of adsorption tanks, the aspirator having a first inlet, a second inlet, and an outlet, The nitrogen-enriched gas production apparatus, wherein the first inlet and the outlet are arranged along the branch pipe, and the second inlet is connected to the suction pipe.
[4] Using a first adsorption tank filled with an adsorbent that adsorbs components other than nitrogen gas in the feed air, a second adsorption tank filled with the adsorbent, and a compressor, nitrogen gas is a nitrogen-enriched gas production method for producing a nitrogen-enriched gas from feed air containing a pressurized adsorption step for obtaining a nitrogen-enriched gas by adsorbing components other than nitrogen gas in the feed air to the adsorbent in the first adsorption tank; a first pressure equalizing step of introducing the gas remaining in the adsorption tank into the second adsorption tank and pressurizing the inside of the second adsorption tank; The adsorbent in the second adsorption tank is introduced into the tank to adsorb components other than nitrogen gas in the feed air, and the inside of the first adsorption tank is decompressed to reduce the pressure in the first adsorption tank. A reduced pressure regeneration step for desorbing components other than nitrogen gas from the adsorbent in the first adsorption tank to regenerate the adsorbent in the first adsorption tank, and the second adsorption tank after the reduced pressure regeneration step and a second pressure equalizing step of introducing the gas remaining in the first adsorption tank into the first adsorption tank and pressurizing the inside of the first adsorption tank, wherein the first pressure equalizing step and the second In either one or both of the pressure equalization steps, the compressed raw air is stored in a compressed raw air tank arranged on the secondary side of the compressor, and in the reduced pressure regeneration step, the compressed raw air tank is stored. By introducing the compressed source air stored in the compressed source air tank into the aspirator disposed on the secondary side, the aspirator, the first adsorption tank, and the second adsorption tank The inside of the first adsorption tank is further depressurized through a suction pipe connecting each of to further reduce the pressure in the second adsorption tank through the suction pipe.

ADVANTAGE OF THE INVENTION According to this invention, the enlargement of a compressor and the increase in the power consumption of a compressor can be suppressed, suppressing the failure of equipment, maintenance cost, and an increase in an installation area.

It is a mimetic diagram showing an example of composition of a gas separation device concerning one embodiment to which the present invention is applied. It is a mimetic diagram showing an example of composition of a gas separation device concerning one embodiment to which the present invention is applied. It is a mimetic diagram showing an example of composition of a gas separation device concerning one embodiment to which the present invention is applied. It is a schematic diagram which shows an example of a structure of the conventional separation apparatus used by the comparative example.

EMBODIMENT OF THE INVENTION Hereinafter, the gas separation apparatus, gas separation method, nitrogen-enriched gas production apparatus, and nitrogen-enriched gas production method of one Embodiment to which this invention is applied are demonstrated in detail, referring drawings. In the drawings used in the following description, in order to make the features easier to understand, the characteristic portions may be enlarged for the sake of convenience, and the dimensional ratios and the like of each component may not necessarily be the same as the actual ones.

<First embodiment>
(Gas separator)
First, the configuration of the gas separation device 1 according to the first embodiment, which is one embodiment of the present invention, will be described. The gas separation device 1 is a device that separates a first component and a second component from a source gas containing the first component and the second component.
Chemical species of the first component and the second component are not particularly limited. Mixed gases commonly used in the field of gas separators can be used as raw material gases.
In the following description, the case where the source gas is source air will be described as an example, but the separation device of the present invention is not limited to the following aspects.

FIG. 1 is a schematic diagram showing an example of the configuration of the gas separation device 1. As shown in FIG. As shown in FIG. 1, the gas separation device 1 includes a compressor 4, a first adsorption tank 5A, a second adsorption tank 5B, a compressed feed air tank 6, and an aspirator . The gas separation device 1 includes a supply pipe L1, an exhaust pipe L2, a first pressure equalization pipe L3, an outlet pipe L4, a second pressure equalization pipe L5, a regeneration pipe L6, a branch pipe L7, and primary pipes L8A and L8B. It further includes next pipes L9A and L9B and a suction pipe L10.

The feed air contains components other than nitrogen gas (first component) and nitrogen gas (second component). Oxygen gas, argon gas, etc. are mainly exemplified as components other than nitrogen gas in the feed air. The gas separation device 1 is a device for separating components other than nitrogen gas (first component) from nitrogen gas (second component). The nitrogen gas separated by the gas separator 1 is a nitrogen-enriched gas in which nitrogen is concentrated and the nitrogen gas concentration is high. Therefore, when the source gas is source air, the gas separation device 1 can also be said to be a nitrogen-enriched gas production device that produces nitrogen-enriched gas from source air containing nitrogen gas.
Each component of the gas separation device 1 (nitrogen-enriched gas production device) will be described in detail below, taking as an example the case where the source gas is source air.

The compressor 4 is a device for compressing raw material air (raw material gas). The compressor 4 is not particularly limited as long as it can compress the raw material air into a high pressure state and supply it to the first adsorption tank 5A, the second adsorption tank 5B and the compressed raw air tank 6, respectively.

Part of the compressed feed air is introduced into the first adsorption tank 5A and the second adsorption tank 5B. Adsorbents 8 are filled in the first adsorption tank 5A and the second adsorption tank 5B, respectively.
In this embodiment, the adsorbent 8 adsorbs components other than nitrogen gas in the raw air. Examples of the adsorbent 8 include molecular sieve activated carbon and synthetic zeolite. Among these, as the adsorbent 8, molecular sieve activated carbon is preferable.
In other embodiments, the adsorbent 8 can be appropriately selected according to the first component to be adsorbed, and is not particularly limited.

A primary pipe L8A is connected to the primary side end of the first adsorption tank 5A, and a secondary pipe L9A is connected to the secondary side end of the first adsorption tank 5A. A primary pipe L8B is connected to the primary end of the second adsorption tank 5B, and a secondary pipe L9B is connected to the secondary end of the second adsorption tank 5B.

A first end of the primary pipe L8A is connected to each of the supply pipe L1 and the exhaust pipe L2 at a connection point A1, and a second end of the primary pipe L8A is a primary side end of the first adsorption tank 5A. is connected with
The first end of the secondary pipe L9A is connected to the secondary side end of the first adsorption tank 5A, and the second end of the secondary pipe L9A is connected to the outlet pipe L4 and the second pressure equalizing pipe. It is connected with each of L5 at the connection point A2.

A first end of the primary pipe L8B is connected to each of the supply pipe L1 and the exhaust pipe L2 at a connection point B1, and a second end of the primary pipe L8B is an end on the primary side of the second adsorption tank 5B. is connected with
The first end of the secondary pipe L9B is connected to the secondary side end of the second adsorption tank 5B, and the second end of the secondary pipe L9B is connected to the lead-out pipe L4 and the second pressure equalizing pipe. It is connected with each of L5 at the connection point B2.

A supply pipe L1 is a pipe for supplying compressed feed air to the first adsorption tank 5A and the second adsorption tank 5B. The supply pipe L1 connects the compressor 4 to each of the first adsorption tank 5A and the second adsorption tank 5B.
A first end of the supply pipe L1 is connected to the compressor 4, and a second end of the supply pipe L1 is branched into a pipe L1A and a pipe L1B at a branch point D2. An end of the pipe L1A is connected to a first end of the primary pipe L8A at a connection point A1. Further, the end of the pipe L1B is connected to the first end of the primary pipe L8B at the connection point B1. A first supply valve 11a is provided on the pipe L1A, and a second supply valve 11b is provided on the pipe L1B.

The branch pipe L7 is a pipe branched from the supply pipe L1. In the first embodiment, the branch pipe L7 is branched from the branch point D1 on the supply pipe L1. The branch point D1 is located on the primary side of the branch point D2. That is, the first end of the branch pipe L7 is connected to the supply pipe L1 at the branch point D1. A second end of the branch pipe L7 is open to the atmosphere.

Compressed raw air tank 6 is provided in branch pipe L7. The rest of the compressed raw air is stored in the compressed raw air tank 6 . The remainder of the compressed feed air is a part of the compressed feed air supplied to the first adsorption tank 5A or the second adsorption tank 5B from the total amount of compressed feed air obtained by the compressor 4. means compressed feed air excluding
Compressed raw air tank 6 is not particularly limited as long as it can store compressed raw air.
A branch pipe L7 between the branch point D1 and the compressed raw air tank 6 is provided with an air tank main valve 17. As shown in FIG.

The exhaust pipe L2 is provided inside the first adsorption tank 5A or the second adsorption tank 5B when desorbing the components adsorbed by the adsorbent in the first adsorption tank 5A or the second adsorption tank 5B. This is the piping for exhausting the gas from the
A first end of the exhaust pipe L2 branches into a pipe L2A and a pipe L2B, and a second end of the exhaust pipe L2 is connected to a branch pipe L7 on the secondary side of the aspirator 7 . As a result, the second end of the exhaust pipe L2 is open to the atmosphere.
An end of the pipe L2A is connected to a first end of the primary pipe L8A at a connection point A1. Also, the end of the pipe L2B is connected to the first end of the primary pipe L8B at the connection point B1. A first exhaust valve 12a is provided on the pipe L2A, and a second exhaust valve 12b is provided on the pipe L2B. An exhaust collecting valve 12 is provided on the second end side of the exhaust pipe L2.

The suction pipe L10 is a pipe that connects the suction device 7 and each of the first adsorption tank 5A and the second adsorption tank 5B. A first end of the suction pipe L10 is connected to a second end of the exhaust pipe L2, and a second end of the suction pipe L10 is connected to the aspirator . Thus, in the first embodiment, the aspirator 7 and each of the first adsorption tank 5A and the second adsorption tank 5B are connected via the exhaust pipe L2 and the suction pipe L10.

The aspirator 7 is provided in a branch pipe L7 on the secondary side of the compressed raw air tank 6. As shown in FIG. A pressure reducing valve 18 and an introduction valve 19 are provided in this order from the primary side in the branch pipe L7 between the compressed raw air tank 6 and the aspirator 7 .
The suction device 7 has a first inlet 7a, a second inlet 7b and an outlet 7c. The first inlet port 7a and the outlet port 7c are arranged on the same pipe along the branch pipe L7. The second introduction port 7b is connected to the suction pipe L10.
In the aspirator 7 having the above structure, when the compressed source air is introduced into the first inlet port 7a of the aspirator 7 and the compressed source air is discharged from the outlet port 7c, for example, a venturi Depressurization occurs like the phenomenon described by the effect. By utilizing this reduced pressure state, the aspirator 7 further reduces the pressure in the first adsorption tank 5A and the inside of the second adsorption tank 5B to below atmospheric pressure by introducing the compressed feed air, thereby performing the first adsorption. The gas in the tank 5A and the second adsorption tank 5B can be sucked.
Specific examples of the suction device 7 include an aspirator, an ejector, and the like. The aspirator 7 may be, for example, a vacuum generator that creates a vacuum by means of the venturi effect.

As described above, the compressed raw air tank 6 introduces the compressed raw air stored in the compressed raw air tank 6 into the first inlet port 7a of the aspirator 7, thereby causing the aspirator 7 to The inside of the first adsorption tank 5A and the inside of the second adsorption tank 5B can be further decompressed via the suction pipe L10 connected to the introduction port 7b of. In the gas separation device 1 (nitrogen-enriched gas production device), when the component adsorbed by the adsorbent in the first adsorption tank 5A or the second adsorption tank 5B is desorbed, the compressed feed air is introduced into the aspirator 7, the aspirator 7 can further reduce the pressure in the first adsorption tank 5A or the second adsorption tank 5B. As a result, the desorption efficiency of the adsorbed components of the adsorbents in the first adsorption tank 5A and the second adsorption tank 5B is improved.

In the conventional apparatus, the inside of the first adsorption tank 5A or the inside of the second adsorption tank 5B was simply opened to the atmosphere. In this case, since the pressure inside the first adsorption tank 5A or the inside of the second adsorption tank 5B gradually becomes the atmospheric pressure, the desorption efficiency of the adsorbed components in the adsorbent 8 cannot be increased.
On the other hand, according to the gas separation device 1 (nitrogen-enriched gas production device), after the inside of the adsorption tank is opened to the atmosphere by opening and closing the exhaust collecting valve 12, the inside of the first adsorption tank 5A or the second adsorption tank The pressure inside 5B can be further reduced from the atmospheric pressure by the aspirator 7 . Therefore, the desorption efficiency of the adsorbed component is improved compared to the conventional device.

The first pressure equalizing pipe L3 is a pipe for equalizing the pressure difference between the first adsorption tank 5A and the second adsorption tank 5B. A first end of the first pressure equalization pipe L3 is connected to the pipe L2A, and a second end of the first pressure equalization pipe L3 is connected to the pipe L2B. A first pressure equalizing valve 13 is provided in the first pressure equalizing pipe L3.

The lead-out pipe L4 is a pipe for taking out the nitrogen-enriched gas from the secondary side of the first adsorption tank 5A and the second adsorption tank 5B. A first end of the lead-out pipe L4 branches into a pipe L4A and a pipe L4B, and a second end of the lead-out pipe L4 is connected to a product gas tank (not shown). The pipe L4A is provided with a first outlet valve 16a, and the pipe L4B is provided with a second outlet valve 16b.

The second pressure equalizing pipe L5 is a pipe for equalizing the pressure difference between the first adsorption tank 5A and the second adsorption tank 5B. A first end of the second pressure equalizing pipe L5 is connected to a second end of the secondary pipe L9A at a connection point A2. A second end of the second pressure equalizing pipe L5 is connected to a second end of the secondary pipe L9B at a connection point B2. A second pressure equalizing valve 15 is provided in the second pressure equalizing pipe L5.

The regeneration pipe L6 is a pipe for introducing a nitrogen-enriched gas as a regeneration gas into each of the first adsorption tank 5A and the second adsorption tank 5B. A first end of the regeneration pipe L6 is connected to the second pressure equalization pipe L5 on the primary side of the second pressure equalization valve 15 . A second end of the regeneration pipe L6 is connected to the second pressure equalization pipe L5 on the secondary side of the second pressure equalization valve 15 . The first end side of the second pressure equalization pipe L5 is the primary side of the second pressure equalization valve 15, and the second end side of the second pressure equalization pipe L5 is the secondary side of the second pressure equalization valve 15. Next side. A regeneration valve 14 is provided in the regeneration pipe L6.

(Effect)
Since the gas separation apparatus 1 (nitrogen-enriched gas production apparatus) described above is provided with the aspirator 7, there is no need to use a vacuum pump when desorbing the components adsorbed by the adsorbent. Therefore, equipment failure, maintenance costs, and an increase in equipment area can be suppressed. Since the gas separation device 1 (nitrogen-enriched gas production device) is provided with the compressed feed air tank 6, there is no need to increase the amount of feed air supplied to the compressor 4. Electric power can be suppressed.

In the field of gas separators, there is a demand for further improvement in the purity of product gases. Since the gas separation device 1 has the above configuration, the efficiency of desorption of the adsorbent component of the adsorbent is improved compared to the conventional device, and the adsorption capacity of the adsorbent can be fully recovered easily. As a result, the purity of the product gas is improved.

(Gas separation method)
A gas separation method (hereinafter referred to as "gas separation method (1)") according to a first embodiment, which is one embodiment of the present invention, will be described below with reference to FIG. 1 and Table 1. In the explanation of the gas separation method (1), as in the explanation of the gas separation device 1, the case where the raw material gas is raw air is explained as an example, but the gas separation method of the present invention is limited to the following aspects. not.

The gas separation method (1) is a method of separating components other than nitrogen gas (first component) from nitrogen gas (second component) using the gas separator 1 . The nitrogen gas separated by the gas separation method (1) is a nitrogen-enriched gas in which nitrogen is concentrated and the nitrogen gas concentration is high. Therefore, when the source gas is source air, the gas separation method (1) can also be said to be the nitrogen-enriched gas production method (1) for producing nitrogen-enriched gas from source air containing nitrogen gas.

Table 1 is an example of the valve opening/closing operation in the gas separation method (1). In addition, in the columns with the description of "open or closed" and the columns with the description of "closed or open" in Table 1, the open/closed state of the valve specified by the valve number in the table is either open or closed. good.
As shown in Table 1, in the gas separation method (1), each step of the pressure adsorption step, the first pressure equalization step, the reduced pressure regeneration step, and the second pressure equalization step is repeated to obtain the first The adsorption tank 5A, the second adsorption tank 5B and the compressor 4 are used to produce a nitrogen-enriched gas from feed air containing nitrogen gas.

In the gas separation method (1), when the first adsorption tank 5A is in the pressure adsorption step, the second adsorption tank 5B is in the reduced pressure regeneration step. When the first adsorption tank 5A is in the reduced pressure regeneration process, the second adsorption tank 5B is in the pressurized adsorption process. Further, when the first adsorption tank 5A is in the first pressure equalization process, the second adsorption tank 5B is in the second pressure equalization process. When the first adsorption tank 5A is in the second pressure equalizing process, the second adsorption tank 5B is in the first pressure equalizing process.
Each step of the first adsorption tank 5A will be described below.

In the pressurized adsorption step, the compressor 4 compresses raw air to obtain compressed raw air. Next, the compressed feed air is introduced into the first adsorption tank 5A to pressurize the inside of the first adsorption tank 5A. Thereafter, components other than nitrogen gas in the feed air are adsorbed by the adsorbent in the first adsorption tank 5A under high pressure to obtain nitrogen-enriched gas.

In the first pressure equalization step, the relatively high-pressure gas remaining in the first adsorption tank 5A after the pressurized adsorption step is introduced into the second adsorption tank 5B to relatively reduce the pressure. Pressurize the inside of the second adsorption tank 5B. As a result, the pressure in the first adsorption tank 5A is lowered to the same level as the pressure in the second adsorption tank 5B.

In the reduced-pressure regeneration step, the compressed feed air is introduced into the second adsorption tank 5B, and components other than nitrogen gas in the feed air are adsorbed by the adsorbent in the second adsorption tank 5B. The pressure inside the adsorption tank 5A is reduced. As a result, adsorbent components such as oxygen gas are desorbed from the adsorbent in the first adsorption tank 5A, and the adsorbent in the first adsorption tank 5A is regenerated. At this time, part of the nitrogen-enriched gas taken out from the secondary side of the second adsorption tank 5B in the pressurized adsorption step is transferred from the secondary side of the first adsorption tank 5A into the first adsorption tank 5A. It is preferable that the introduction promotes desorption of the adsorbed component.

In the second pressure equalization step, the relatively high-pressure gas remaining in the second adsorption tank 5B after the reduced-pressure regeneration step is introduced into the first adsorption tank 5A to relatively reduce the pressure. Pressurize the inside of the first adsorption tank 5A. As a result, the pressure in the second adsorption tank 5B is lowered to the same level as the pressure in the first adsorption tank 5A.

Next, with reference to Table 1, the gas separation method (1) will be described in detail from the second pressure equalizing step.
First, in the second pressure equalization step, the first adsorption tank 5A is in a state immediately before performing the pressure adsorption step, and the second adsorption tank 5B is in a state just before performing the reduced pressure regeneration step. Specifically, the first pressure equalizing valve 13, the second pressure equalizing valve 15, and the air tank main valve 17 are open, and the first supply valve 11a, the second supply valve 11b, the exhaust collecting valve 12, The first exhaust valve 12a, the second exhaust valve 12b, the first outlet valve 16a, the second outlet valve 16b, and the inlet valve 19 are closed.

In the second pressure equalization step, the first pressure equalization valve 13 is open. Therefore, the relatively high-pressure gas in the second adsorption tank 5B is supplied from the primary side of the second adsorption tank 5B to the primary pipe L8B, part of the pipe L2B, the first pressure equalizing pipe L3, and the pipe L2A. It is introduced into the first adsorption tank 5A from the primary side of the first adsorption tank 5A via the part and the primary pipe L8A in this order.
Then, in the second pressure equalization step, the second pressure equalization valve 15 is opened. Therefore, the relatively high pressure gas in the second adsorption tank 5B flows from the secondary side of the second adsorption tank 5B through the secondary pipe L9B, the second pressure equalizing pipe L5 and the secondary pipe L9A in this order. It is introduced into the first adsorption tank 5A from the secondary side of the first adsorption tank 5A via the first adsorption tank 5A.
Thus, in the second pressure equalization step, the relatively high-pressure gas remaining in the second adsorption tank 5B after the pressurized adsorption step is removed from the first adsorption tank after the depressurization regeneration step. Collected within 5A.

In the second pressure equalizing process, the air tank main valve 17 is opened. Therefore, the compressed raw air discharged from the compressor 4 is introduced into the compressed raw air tank 6 and stored in the compressed raw air tank 6 .

Next, the pressurized adsorption step will be described. In the pressurized adsorption step, the state of the first adsorption tank 5A is switched in order of states S1, S2 and S3.
In the state S1 of the pressurized adsorption step, the first supply valve 11a, the exhaust collection valve 12, the second exhaust valve 12b, and the first lead-out valve 16a are open, and the second supply valve 11b and the first exhaust valve 16a are open. The exhaust valve 12a, the first pressure equalizing valve 13, the second pressure equalizing valve 15, the second lead-out valve 16b, and the air tank main valve 17 are closed.

In the state S1, since the first supply valve 11a and the first outlet valve 16a are open, the raw air compressed by the compressor 4 passes through the supply pipe L1, the pipe L1A and the primary pipe L8A in this order. It is introduced into the first adsorption tank 5A, and the inside of the first adsorption tank 5A is pressurized. Then, components other than nitrogen gas such as oxygen and carbon dioxide in the feed air are adsorbed by the adsorbent 8 in the first adsorption tank 5A to obtain a nitrogen-enriched gas in which nitrogen is concentrated. The obtained nitrogen-enriched gas is led out from the first adsorption tank 5A to a product gas tank (not shown) via the secondary pipe L9A, the pipe L4A, and the lead-out pipe L4 in this order.

In the state S1, since the second exhaust valve 12b and the exhaust collecting valve 12 are open, the second adsorption tank 5B is opened to the atmosphere via the primary pipe L8B, the pipe L2B and the exhaust pipe L2 in this order. there is As a result, the inside of the second adsorption tank 5B is decompressed, the adsorbent components such as oxygen gas are desorbed from the adsorbent 8 in the second adsorption tank 5B, and the exhaust gas passes through the exhaust pipe L2 to the second adsorption tank. It is discharged from 5B. Thereby, regeneration of the adsorbent 8 in the second adsorption tank 5B is started.

Next, the state S2 of the pressurized adsorption process will be described. In the state S2, the opening and closing states of the valves are the same as in the state S1 except that the introduction valve 19 is open and the exhaust collecting valve 12 is closed.
In state S2, since the introduction valve 19 is open, the compressed raw air stored in the compressed raw air tank 6 is introduced into the first inlet 7a of the aspirator 7 via the branch pipe L7. . At this time, the pressure of the compressed raw material air introduced into the aspirator 7 may be adjusted by the pressure reducing valve 18 provided in the branch pipe L7.

In the pressurized adsorption step, the compressed source air stored in the compressed source air tank 6 is introduced into the first inlet port 7 a of the aspirator 7 . As a result, the inside of the second adsorption tank 5B is further depressurized by the suction device 7 via the suction pipe L10 connected to the second inlet 7b. As a result, the desorption of the adsorbent components of the adsorbent 8 in the second adsorption tank 5B is promoted, and the desorption efficiency is improved.

In the conventional method, the inside of the second adsorption tank 5B was simply opened to the atmosphere. In this case, since the pressure in the second adsorption tank 5B gradually reaches the atmospheric pressure, the desorption efficiency of the adsorbed components in the adsorbent 8 cannot be increased.
On the other hand, according to the gas separation method (1), the pressure inside the second adsorption tank 5B can be further reduced from the atmospheric pressure by the aspirator 7 . Therefore, the desorption efficiency of the adsorbed component is improved compared to the conventional device.

Next, the state S3 of the pressurized adsorption process will be described. In state S3, when the second exhaust valve 12b and the introduction valve 19 are open, the exhaust collecting valve 12 is closed. When the introduction valve 19 is closed, the exhaust collecting valve 12 is open.
When both the second exhaust valve 12b and the introduction valve 19 are open, components other than nitrogen gas desorbed from the adsorbent 8 in the second adsorption tank 5B are discharged via the exhaust pipe L2. .
Regeneration of the adsorbent 8 in the second adsorption tank 5B is completed through state S3.

When the first adsorption tank 5A is in the pressure adsorption step, the regeneration valve 14 may be either open or closed. When the regeneration valve 14 is open, part of the nitrogen-enriched gas in the first adsorption tank 5A is transferred to the secondary pipe L9A, part of the second pressure equalizing pipe L5, the regeneration pipe L6, the secondary pipe It is introduced into the second adsorption tank 5B from the secondary side of the second adsorption tank 5B via L9B. As a result, the inside of the second adsorption tank 5B is purged with the nitrogen-enriched gas, further promoting regeneration of the adsorbent 8 in the second adsorption tank 5B.

Next, the first pressure equalizing step will be described.
In the first pressure equalization step, the first adsorption tank 5A is in a state just before performing the reduced pressure regeneration step, and the second adsorption tank 5B is in a state just before performing the pressure adsorption step. Specifically, the first pressure equalizing valve 13, the second pressure equalizing valve 15, and the air tank main valve 17 are open, and the first supply valve 11a, the second supply valve 11b, the exhaust collecting valve 12, The first exhaust valve 12a, the second exhaust valve 12b, the first outlet valve 16a, the second outlet valve 16b, and the inlet valve 19 are closed.

In the first pressure equalization step, the first pressure equalization valve 13 is open. Therefore, the relatively high-pressure gas in the first adsorption tank 5A flows from the primary side of the first adsorption tank 5A through the primary pipe L8A, part of the pipe L2A, the first pressure equalizing pipe L3, and the pipe L2B. It is introduced into the second adsorption tank 5B from the primary side of the second adsorption tank 5B through the part and the primary pipe L8B in this order.
Then, in the first pressure equalization step, the second pressure equalization valve 15 is opened. Therefore, the relatively high pressure gas in the first adsorption tank 5A flows from the secondary side of the first adsorption tank 5A through the secondary pipe L9A, the second pressure equalizing pipe L5 and the secondary pipe L9B in this order. It is then introduced into the second adsorption tank 5B from the secondary side of the first adsorption tank 5A.
Thus, in the first pressure equalization step, relatively high-pressure gas remaining in the first adsorption tank 5A after the pressurized adsorption step is transferred to the second adsorption tank after the reduced pressure regeneration step. Collected in 5B.

In the first pressure equalizing step, the air tank main valve 17 is open. Therefore, the compressed raw air discharged from the compressor 4 is introduced into the compressed raw air tank 6 and stored in the compressed raw air tank 6 .

Next, the reduced-pressure regeneration step will be described.
In the reduced pressure regeneration step, the state of the first adsorption tank 5A is switched in order of states S4, S5 and S6.
In the state S4 of the decompression regeneration process, the second supply valve 11b, the exhaust collecting valve 12, the first exhaust valve 12a, and the second lead-out valve 16b are open, and the first supply valve 11a and the second outlet valve 16b are open. The exhaust valve 12b, the first pressure equalizing valve 13, the second pressure equalizing valve 15, the first lead-out valve 16a, and the air tank main valve 17 are closed.

In state S4, since the second supply valve 11b and the second outlet valve 16b are open, the raw air compressed by the compressor 4 passes through the supply pipe L1, the pipe L1B and the primary pipe L8B in this order. It is introduced into the second adsorption tank 5B, and the inside of the second adsorption tank 5B is pressurized. Then, components other than nitrogen gas such as oxygen and carbon dioxide in the feed air are adsorbed by the adsorbent 8 in the second adsorption tank 5B to obtain a nitrogen-enriched gas in which nitrogen is concentrated. The obtained nitrogen-enriched gas is led out from the second adsorption tank 5B to a product gas tank (not shown) via the secondary pipe L9B, the pipe L4B, and the lead-out pipe L4 in this order.

In the state S4, since the exhaust collecting valve 12 and the first exhaust valve 12a are open, the first adsorption tank 5A is opened to the atmosphere via the primary pipe L8A, the pipe L2A and the exhaust pipe L2 in this order. there is Therefore, the inside of the first adsorption tank 5A is decompressed, the adsorbent component such as oxygen gas is desorbed from the adsorbent 8 in the first adsorption tank 5A, and the exhaust gas passes through the exhaust pipe L2 to the first adsorption tank. It is discharged from 5A. As a result, regeneration of the adsorbent 8 in the first adsorption tank 5A is started.

Next, the state S5 of the reduced-pressure regeneration process will be described.
In the state S5, the opening and closing states of the valves are the same as in the state S4 of the decompression regeneration step, except that the introduction valve 19 is open and the exhaust collecting valve 12 is closed.
In state S5, since the inlet valve 19 is open, the compressed raw air stored in the compressed raw air tank 6 is introduced into the first inlet 7a of the aspirator 7 via the branch pipe L7. At this time, the pressure of the compressed raw material air introduced into the aspirator 7 may be adjusted by the pressure reducing valve 18 provided in the branch pipe L7.

In the decompression regeneration step, the compressed raw air stored in the compressed raw air tank 6 is introduced into the first inlet port 7 a of the aspirator 7 . As a result, the inside of the first adsorption tank 5A is further depressurized by the suction device 7 via the suction pipe L10 connected to the second inlet 7b. As a result, the desorption of the adsorbent components of the adsorbent 8 in the first adsorption tank 5A is promoted, and the desorption efficiency is improved.
Regeneration of the adsorbent 8 in the first adsorption tank 5A is completed through state S6.

In the conventional method, the inside of the first adsorption tank 5A was simply opened to the atmosphere. In this case, since the pressure in the first adsorption tank 5A gradually becomes atmospheric pressure, the desorption efficiency of the adsorbed components in the adsorbent 8 cannot be increased.
On the other hand, according to the gas separation method (1), the pressure inside the first adsorption tank 5A can be further reduced from the atmospheric pressure by the aspirator 7 . Therefore, the desorption efficiency of the adsorbed component is improved compared to the conventional device.

Next, the state S6 of the reduced-pressure regeneration step will be described. In state S6, the valve opening/closing state is the same as in state S5 of the decompression regeneration step, except that the first exhaust valve 12a and the introduction valve 19 may be either open or closed.
When both the first exhaust valve 12a and the introduction valve 19 are open, components other than nitrogen gas desorbed from the adsorbent 8 in the first adsorption tank 5A are discharged via the exhaust pipe L2. .

When the first adsorption tank 5A is in the reduced-pressure regeneration step, the regeneration valve 14 may be either open or closed. When the regeneration valve 14 is in an open state, part of the nitrogen-enriched gas in the second adsorption tank 5B flows through the secondary pipe L9B, part of the second pressure equalizing pipe L5, the regeneration pipe L6, the secondary pipe Via L9A, it is introduced into the first adsorption tank 5A from the secondary side of the first adsorption tank 5A. As a result, the inside of the first adsorption tank 5A is purged with the nitrogen-enriched gas, and regeneration of the adsorbent 8 in the first adsorption tank 5A is promoted.

Thus, in the gas separation method (1), in the first pressure equalizing step and the second pressure equalizing step, the compressed raw air is stored in the compressed raw air tank arranged on the secondary side of the compressor 4. is doing. However, the compressed raw air may be stored in a compressed raw air tank arranged on the secondary side of the compressor 4 in either the first pressure equalizing step or the second pressure equalizing step.

(Effect)
In the gas separation method (1) described above, the compressed raw air stored in the compressed raw air tank 6 is placed in the aspirator 7 arranged on the secondary side of the compressed raw air tank 6 in the decompression regeneration step. is introduced, the inside of the first adsorption tank 5A is further reduced in pressure via the suction pipe L10, so that it is not necessary to use a vacuum pump when desorbing the components adsorbed by the adsorbent. Therefore, equipment failure, maintenance costs, and an increase in equipment area can be suppressed. In the gas separation method (1), in either or both of the first pressure equalization step and the second pressure equalization step, the raw air compressed in the compressed raw air tank 6 is stored. There is no need to increase the amount of feed air to be supplied, and the enlargement of the compressor and power consumption of the compressor can be suppressed.
Furthermore, in the gas separation method (1), the raw air compressed in the pressurized adsorption step is introduced into the aspirator 7, thereby further reducing the pressure in the second adsorption tank 5B with the aspirator 7 via the suction pipe L10. Therefore, the desorption efficiency of the adsorbent component of the adsorbent is improved, and the adsorption capacity of the adsorbent can be fully recovered easily. As a result, the purity of the product gas is improved.

According to the gas separation method (1), it is not necessary to continuously supply the raw material gas compressed by the compressor 4 to the aspirator. Therefore, as described above with respect to the mixed gas separation method described in Patent Document 2, when trying to intermittently supply pressurized air to the ejector for the purpose of solving problems such as an increase in the size of the compressor, Compressor failure due to excessive load on the compressor can be avoided.

<Second embodiment>
(Gas separator)
The configuration of the gas separation device 2 according to the second embodiment, which is one embodiment of the present invention, will be described below. Similar to the gas separation device 1, when the source gas is source air, the gas separation device 2 can also be said to be a nitrogen-enriched gas production device that produces nitrogen-enriched gas from source air containing nitrogen gas. In the explanation of the gas separation device 2, the same words and the same reference numerals are used for the same configurations as those explained in the gas separation device 1, and the explanation thereof is omitted.

FIG. 2 is a schematic diagram showing an example of the configuration of the gas separation device 2. As shown in FIG. As shown in FIG. 2, the gas separation device 2 includes a compressor 4, a first adsorption tank 5A, a second adsorption tank 5B, a compressed feed air tank 6, and an aspirator . The gas separation device 2 includes a supply pipe L1, an exhaust pipe L2, a first pressure equalization pipe L3, an outlet pipe L4, a second pressure equalization pipe L5, a regeneration pipe L6, a branch pipe L7, and primary pipes L8A and L8B. It further includes next pipes L9A and L9B and a suction pipe L10.
Each component of the gas separation device 2 will be described in detail below.

The suction pipe L10 is a pipe for reducing the pressure inside the first adsorption tank 5A and the inside of the second adsorption tank 5B by the suction device 7 . In the second embodiment, the first end of the suction pipe L10 is branched into a pipe L10A and a pipe L10B. A second end of the suction pipe L10 is connected to the second introduction port 7b of the suction device 7 .
The end of the pipe L10A is connected to the primary pipe L8A at the connection point A3. Further, the end of the pipe L10B is connected to the primary pipe L8B at the connection point B3. A first suction valve 21a is provided on the pipe L10A, and a second suction valve 21b is provided on the pipe L10B.

(Effect)
The gas separation device 2 described above has the same effects as the gas separation device 1 .

(Gas separation method)
A gas separation method (hereinafter referred to as "gas separation method (2)") according to a second embodiment, which is one embodiment of the present invention, will be described below with reference to FIG. 2 and Table 2. In the case where the source gas is source air as in the gas separation method (1), the gas separation method (2) is a nitrogen-enriched gas production method (2) for producing a nitrogen-enriched gas from a source air containing nitrogen gas. It can also be said that In the explanation of the gas separation method (2), the same words and the same reference numerals will be used for the same configurations as those explained in the gas separation method (1), and the explanation thereof will be omitted.

Table 2 is an example of the valve opening/closing operation in the gas separation method (2). In addition, in the columns with "open or closed" and the columns with "closed or open" in Table 2, the open/closed state of the valve specified by the valve number in the table can be either open or closed. good.

Next, with reference to Table 2, the gas separation method (2) will be described in detail from the second pressure equalizing step.

In the second pressure equalization step of the gas separation method (2), as in the second pressure equalization step of the gas separation method (1), the relative Generally, the high-pressure gas is recovered in the first adsorption tank 5A where the decompression regeneration step has been completed. Compressed raw air discharged from the compressor 4 is introduced into the compressed raw air tank 6 and stored in the compressed raw air tank 6 .

Next, the pressurized adsorption step of gas separation method (2) will be described.
In state S1 of the pressurized adsorption step of gas separation method (2), as in state S1 of the pressurized adsorption step of gas separation method (1), the nitrogen-enriched gas flows through secondary pipe L9A, pipe L4A, and outlet pipe L4. in this order from the first adsorption tank 5A to a product gas tank (not shown). In the state S1, the pressure inside the second adsorption tank 5B is reduced because the second exhaust valve 12b is open. As a result, the adsorbent component such as oxygen gas is desorbed from the adsorbent 8 in the second adsorption tank 5B, and is discharged as an exhaust gas from the second adsorption tank 5B via the exhaust pipe L2. Thereby, regeneration of the adsorbent 8 in the second adsorption tank 5B is started.

Next, the state S2 of the pressurized adsorption step of the gas separation method (2) will be described. As shown in Table 2, in the state S2 of the pressurized adsorption step of the gas separation method (2), the introduction valve 19 and the second suction valve 21b are open, and the second exhaust valve 12b is closed. is the open/closed state of the valve similar to the state S1.

In state S2, since the introduction valve 19 is open, the compressed raw air stored in the compressed raw air tank 6 is introduced into the first inlet 7a of the aspirator 7 via the branch pipe L7. . Since the second suction valve 21b is open, the pressure inside the second adsorption tank 5B is further reduced by the suction device 7 via the suction pipe L10 connected to the second inlet 7b.
Thereafter, regeneration of the adsorbent 8 in the second adsorption tank 5B is completed through state S3.
When the first adsorption tank 5A is in the pressure adsorption step, the regeneration valve 14 may be either open or closed.

Next, the first pressure equalization step of gas separation method (2) will be described.
In the first pressure equalization step of the gas separation method (2), as in the first pressure equalization step of the gas separation method (1), the relative Generally, the high-pressure gas is recovered in the second adsorption tank 5B where the decompression regeneration step has been completed. Compressed raw air discharged from the compressor 4 is introduced into the compressed raw air tank 6 and stored in the compressed raw air tank 6 .

Next, the vacuum regeneration step of the gas separation method (2) will be described.
In the state S4 of the reduced pressure regeneration step of the gas separation method (2), as in the state S4 of the reduced pressure regeneration step of the gas separation method (1), the nitrogen-enriched gas is discharged from the second adsorption tank 5B to the product gas tank (not shown). is derived to Then, an adsorbent component such as oxygen gas is desorbed from the adsorbent 8 in the first adsorption tank 5A, and is discharged as an exhaust gas from the first adsorption tank 5A via the exhaust pipe L2. As a result, regeneration of the adsorbent 8 in the first adsorption tank 5A is started.

Next, the state S5 of the reduced-pressure regeneration step in the gas separation method (2) will be described. As shown in Table 2, in the state S5 of the reduced-pressure regeneration step of the gas separation method (2), except that the introduction valve 19 and the first suction valve 21a are open and the first exhaust valve 12a is closed, , the open/closed state of the valve similar to the state S4.
In state S<b>5 , the compressed raw air stored in the compressed raw air tank 6 is introduced into the first inlet 7 a of the suction device 7 . As a result, the inside of the first adsorption tank 5A is further depressurized by the suction device 7 via the suction pipe L10 connected to the second inlet 7b. As a result, compared with the gas separation method (1), the desorption of the adsorbent components of the adsorbent 8 in the first adsorption tank 5A is further promoted, and the desorption efficiency is further improved.
Thereafter, through state S6, the regeneration of the adsorbent 8 in the first adsorption tank 5A is completed.
When the first adsorption tank 5A is in the reduced-pressure regeneration step, the regeneration valve 14 may be either open or closed.

(Effect)
The gas separation method (2) described above has the same effects as the gas separation method (1).

<Third Embodiment>
(Gas separator)
The configuration of the gas separation device 3 according to the third embodiment, which is one embodiment of the present invention, will be described below. As with the gas separation device 1, when the source gas is source air, the gas separation device 3 can also be said to be a nitrogen-enriched gas production device that produces nitrogen-enriched gas from source air containing nitrogen gas. In the explanation of the gas separation device 3, the same words and the same reference numerals will be used for the same configurations as those explained in the gas separation devices 1 and 2, and the explanation thereof will be omitted.

FIG. 3 is a schematic diagram showing an example of the configuration of the gas separation device 3. As shown in FIG. As shown in FIG. 3, the gas separation device 3 includes a compressor 4, a first adsorption tank 5A, a second adsorption tank 5B, a first compressed raw air tank 6a, a second compressed raw air tank 6b, and a suction a vessel 7; The gas separation device 3 includes a supply pipe L1, an exhaust pipe L2, a first pressure equalization pipe L3, an outlet pipe L4, a second pressure equalization pipe L5, a regeneration pipe L6, a branch pipe L11, and primary pipes L8A and L8B. Further, the following pipes L9A and L9B are provided.
Each component of the gas separation device 3 will be described in detail below.

In the third embodiment, the first compressed raw air tank 6a and the second compressed raw air tank 6b are provided in the branch pipe L11. The rest of the compressed raw air is stored in the first compressed raw air tank 6a and the second compressed raw air tank 6b. That is, the remainder obtained by subtracting the amount of raw air introduced into the adsorption tank from the raw air supplied from the compressor 4 is stored in the first compressed raw air tank 6a and the second compressed raw air tank 6b. .
The first compressed raw air tank 6a and the second compressed raw air tank 6b are not particularly limited as long as they can store compressed raw air.

In the third embodiment, the branch pipe L11 is a pipe branched from the supply pipe L1. A first end of the branch pipe L11 is branched into a pipe L11A and a pipe L11B at a branch point D4. A second end of the branch pipe L11 is open to the atmosphere.
In the third embodiment, the pipe L11A branches off from the branch point D1 on the supply pipe L1. A pipe L11A between the branch point D1 and the branch point D4 is provided with a first air tank main valve 17a, a first compressed feed air tank 6a, and a first introduction valve 19a in this order from the primary side. .
In the third embodiment, the pipe L11B branches off from the branch point D3 on the supply pipe L1. The branch point D3 is located on the primary side of the branch point D1. A pipe L11B between the branch point D3 and the branch point D4 is provided with a first air tank main valve 17b, a second compressed feed air tank 6b, and a second introduction valve 19b in this order from the primary side. .

The aspirator 7 is provided in the branch pipe L11 on the secondary side of the first compressed raw air tank 6a and the second compressed raw air tank 6b. A pressure reducing valve 18 is provided in the branch pipe L11 between the branch point D4 and the aspirator 7 .

(Effect)
The gas separation device 3 described above has the same effects as the gas separation device 1 .

(Gas separation method)
Hereinafter, a gas separation method (hereinafter referred to as "gas separation method (3)") according to a third embodiment, which is one embodiment of the present invention, will be described with reference to FIG. 3 and Table 3. In the case where the source gas is source air as in the gas separation method (1), the gas separation method (3) is a nitrogen-enriched gas production method (3) for producing a nitrogen-enriched gas from a source air containing nitrogen gas. It can also be said that In the explanation of the gas separation method (3), the same words and the same reference numerals are used for the same configurations as those explained in the gas separation method (1), and the explanation thereof is omitted.

Table 3 is an example of the valve opening/closing operation in the gas separation method (3). In Table 3, in the columns with "open or closed" and the columns with "closed or open", the open/closed state of the valve specified by the valve number in the table can be either open or closed. good.

Next, with reference to Table 3, the gas separation method (3) will be described in detail from the second pressure equalizing step.

In the second pressure equalization step of the gas separation method (3), the relatively high-pressure gas remaining in the second adsorption tank 5B is recovered in the first adsorption tank 5A. Compressed raw air discharged from the compressor 4 is introduced into the first compressed raw air tank 6a and stored in the first compressed raw air tank 6a.

Next, the pressurized adsorption step of gas separation method (3) will be described.
In the state S1 of the pressurized adsorption step of the gas separation method (3), as in the state S1 of the pressurized adsorption step of the gas separation method (1), the nitrogen-enriched gas is transferred from the first adsorption tank 5A to a product (not shown) It is led out to the gas tank. In the state S1, the pressure inside the second adsorption tank 5B is reduced because the second exhaust valve 12b is open. As a result, the adsorbent component such as oxygen gas is desorbed from the adsorbent 8 in the second adsorption tank 5B, and is discharged as an exhaust gas from the second adsorption tank 5B via the exhaust pipe L2. Thereby, regeneration of the adsorbent 8 in the second adsorption tank 5B is started.

Next, the state S2 of the pressurized adsorption step of the gas separation method (3) will be described. As shown in Table 3, in the state S2 of the pressurized adsorption step of the gas separation method (3), the valve opening/closing state is the same as in the state S1 except that the second introduction valve 19b is open. .

In state S2, since the second inlet valve 19b is open, the compressed raw air stored in the second compressed raw air tank 6b is introduced into the first inlet of the aspirator 7 via the branch pipe L11. 7a. Since the second exhaust valve 12b is open, the inside of the second adsorption tank 5B is further depressurized by the aspirator 7 via the suction pipe L10 connected to the second inlet 7b.
Thereafter, regeneration of the adsorbent 8 in the second adsorption tank 5B is completed through state S3.
When the first adsorption tank 5A is in the pressure adsorption step, the regeneration valve 14 may be either open or closed.

Next, the first pressure equalization step of gas separation method (3) will be described.
In the first pressure equalization step of the gas separation method (3), relatively high-pressure gas remaining in the first adsorption tank 5A is recovered in the second adsorption tank 5B. Compressed raw air discharged from the compressor 4 is introduced into the second compressed raw air tank 6b and stored in the second compressed raw air tank 6b.

Next, the vacuum regeneration step of the gas separation method (3) will be described.
In the state S4 of the reduced pressure regeneration step of the gas separation method (3), similarly to the state S4 of the pressurized adsorption step of the gas separation method (1), the nitrogen-enriched gas is transferred from the second adsorption tank 5B to the product gas (not shown). It is led out to the tank. In state S4, since the first exhaust valve 12a is open, the pressure inside the first adsorption tank 5A is reduced. As a result, the adsorbent component such as oxygen gas is desorbed from the adsorbent 8 in the first adsorption tank 5A, and is discharged as exhaust gas from the first adsorption tank 5A via the exhaust pipe L2. As a result, regeneration of the adsorbent 8 in the first adsorption tank 5A starts.

Next, the state S5 of the reduced-pressure regeneration step in the gas separation method (3) will be described. As shown in Table 3, in the state S5 of the reduced-pressure regeneration step of the gas separation method (3), the valve opening/closing state is the same as in the state S4 except that the first introduction valve 19a is open.

In the state S5, since the first introduction valve 19a is open, the compressed raw air stored in the first compressed raw air tank 6a is introduced into the first inlet of the aspirator 7 via the branch pipe L11. 7a. Since the first exhaust valve 12a is open, the inside of the first adsorption tank 5A is further depressurized by the aspirator 7 via the suction pipe L10 connected to the second inlet 7b.
Thereafter, through state S6, the regeneration of the adsorbent 8 in the first adsorption tank 5A is completed.
When the first adsorption tank 5A is in the reduced-pressure regeneration step, the regeneration valve 14 may be either open or closed.

(Effect)
The gas separation method (3) described above has the same effects as the gas separation method (1).

Although several embodiments of the invention have been described above, the invention is not limited to such specific embodiments. In addition, addition, omission, substitution, and other changes of configuration may be made to the present invention within the scope of the gist of the present invention described in the claims.

<Example>
EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited by the following description.

(Example 1)
In Example 1, using the gas separation apparatus 1 shown in FIG. 1, nitrogen gas was separated from components other than nitrogen gas according to the valve opening/closing operations shown in Table 1 to produce nitrogen-enriched gas. In Example 1, the lowest pressure [kPaG] of each adsorption tank during the production of nitrogen-enriched gas was measured, and the oxygen concentration [vol. ppm] was measured. The results are shown in Table 5 together with the execution times of the pressurized adsorption process and the pressure equalization process.

(Comparative example 1)
A conventional separation apparatus 101 shown in FIG. 4 was prepared. A conventional separation device 101 includes a compressor 4, a first adsorption tank 5A and a second adsorption tank 5B. The gas separation device 1 includes a supply pipe L1, an exhaust pipe L2, a first pressure equalization pipe L3, an outlet pipe L4, a second pressure equalization pipe L5, a regeneration pipe L6, primary pipes L8A and L8B, secondary pipes L9A, and L9B. That is, the conventional separation device 101 has the same device configuration as the gas separation device 1 except that it does not include the compressed feed air tank 6, the aspirator 7, and the branch pipe L7.

Using the conventional separator 101, the conditions such as the flow rate of the product gas, the supply flow rate of the compressed feed air, and the flow rate of the regeneration gas were set to the same conditions as in Example 1. produced gas. In Comparative Example 1, the lowest pressure [kPaG] of each adsorption tank during production of nitrogen gas was measured, and the oxygen concentration [vol. ppm] was measured. The results are shown in Table 5 together with the execution times of the pressurized adsorption process and the pressure equalization process.

As shown in Table 5, the results of Example 1 show that the flow rate of the product gas can be maintained without increasing the supply flow rate of the compressed feed air, the oxygen concentration in the product gas is reduced, and the purity of the product gas is reduced. was confirmed to improve.
Since the oxygen concentration in the product gas is lowered, the results of Example 1 show that the purity of the product gas can be maintained even when the flow rate of the product gas is increased. Therefore, according to the nitrogen-enriched gas production apparatus of the present invention, it is suggested that the production efficiency of the product gas is improved.
Since the flow rate of the product gas can be maintained without increasing the supply flow rate of the compressed feed air, the equipment can be made smaller, the flow rate of the feed air required for the flow rate of the product gas can be suppressed, and the yield of the product gas can be improved. It is suggested that

DESCRIPTION OF SYMBOLS 1, 2, 3... Gas separator, 4... Compressor, 5A... Second adsorption tank 5B... Second adsorption tank, 6... Compressed feed air tank, 7... Aspirator, 8... Adsorbent, 101... Conventional separation device, L1... supply pipe, L2... exhaust pipe, L3... first pressure equalization pipe, L4... lead-out pipe, L5... second pressure equalization pipe, L6... regeneration pipe, L7, L11... branch pipe, L8A , L8B... primary pipe, L9A, L9B... secondary pipe, L10... suction pipe

Claims (4)

A gas separation device for separating the first component and the second component from a raw material gas containing the first component and the second component,
a compressor for compressing the raw material gas;
a plurality of adsorption tanks into which a portion of the compressed source gas is introduced and filled with an adsorbent that adsorbs the first component in the source gas;
a supply pipe connecting each of the plurality of adsorption tanks and the compressor;
one or more branch pipes branching from the supply pipe;
one or more compressed source gas tanks in which the remainder of the compressed source gas is stored;
an aspirator having a first inlet, a second inlet, and an outlet ;
a suction pipe connecting the aspirator and each of the plurality of adsorption tanks;
with
The branch pipe is provided with the compressed raw material gas tank and the aspirator in order from the primary side,
The gas separation device, wherein the first inlet and the outlet are arranged along the branch pipe, and the second inlet is connected to the suction pipe. Using a first adsorption tank filled with an adsorbent, a second adsorption tank filled with the adsorbent, and a compressor, a raw material gas containing a first component and a second component is separated from the first A gas separation method for separating the component of and the second component,
The compressed raw material gas is introduced into the first adsorption tank to pressurize the inside of the first adsorption tank to remove the first component in the raw material gas from the adsorption in the first adsorption tank. a pressurized adsorption step of separating the first component and the second component by adsorbing an agent;
a first pressure equalizing step of introducing gas remaining in the first adsorption tank after the pressure adsorption step into the second adsorption tank to pressurize the inside of the second adsorption tank;
introducing the compressed source gas into the second adsorption tank to adsorb the first component in the source gas to the adsorbent in the second adsorption tank, and performing the first adsorption; a reduced pressure regeneration step of reducing the pressure in the tank to desorb the first component from the adsorbent in the first adsorption tank to regenerate the adsorbent in the first adsorption tank;
a second pressure equalization step of introducing the gas remaining in the second adsorption tank after the reduced pressure regeneration step into the first adsorption tank and pressurizing the inside of the first adsorption tank; have
in one or both of the first pressure equalizing step and the second pressure equalizing step , storing the remainder of the source gas compressed by the compressor in a compressed source gas tank;
In the reduced-pressure regeneration step, by introducing the compressed raw material gas stored in the compressed raw material gas tank into an aspirator, the aspirator, the first adsorption tank, and the second adsorption tank Further reducing the pressure in the first adsorption tank through a suction pipe connecting each,
In the pressurized adsorption step, the compressed source gas stored in the compressed source gas tank is introduced into the aspirator to further reduce the pressure in the second adsorption tank through the suction pipe. , gas separation method. A nitrogen-enriched gas production apparatus for producing nitrogen-enriched gas from raw air containing nitrogen gas,
a compressor for compressing the raw air;
a plurality of adsorption tanks into which part of the compressed source air is introduced and filled with an adsorbent that adsorbs components other than nitrogen gas in the source air;
a supply pipe connecting each of the plurality of adsorption tanks and the compressor;
one or more branch pipes branching from the supply pipe;
one or more compressed source gas tanks in which the remainder of the compressed source gas is stored;
an aspirator having a first inlet, a second inlet, and an outlet ;
a suction pipe connecting the aspirator and each of the plurality of adsorption tanks;
with
The branch pipe is provided with the compressed raw material gas tank and the aspirator in order from the primary side,
The nitrogen-enriched gas production apparatus, wherein the first inlet and the outlet are arranged along the branch pipe, and the second inlet is connected to the suction pipe. Using a first adsorption tank filled with an adsorbent that adsorbs components other than nitrogen gas in the feed air, a second adsorption tank filled with the adsorbent, and a compressor, feed air containing nitrogen gas A nitrogen-enriched gas production method for producing a nitrogen-enriched gas from
The compressed feed air is introduced into the first adsorption tank to pressurize the inside of the first adsorption tank, and the components other than nitrogen gas in the feed air are adsorbed in the first adsorption tank. a pressurized adsorption step of adsorbing with an agent to obtain a nitrogen-enriched gas;
a first pressure equalizing step of introducing gas remaining in the first adsorption tank after the pressure adsorption step into the second adsorption tank to pressurize the inside of the second adsorption tank;
The compressed feed air is introduced into the second adsorption tank to cause the adsorbent in the second adsorption tank to adsorb components other than nitrogen gas in the feed air, and the first adsorption is performed. a reduced pressure regeneration step of reducing the pressure in the tank to desorb components other than nitrogen gas from the adsorbent in the first adsorption tank to regenerate the adsorbent in the first adsorption tank;
a second pressure equalization step of introducing the gas remaining in the second adsorption tank after the reduced pressure regeneration step into the first adsorption tank and pressurizing the inside of the first adsorption tank; have
in one or both of the first pressure equalizing step and the second pressure equalizing step , storing the remainder of the source gas compressed by the compressor in a compressed source gas tank;
In the reduced-pressure regeneration step, by introducing the compressed raw material gas stored in the compressed raw material gas tank into an aspirator, the aspirator, the first adsorption tank, and the second adsorption tank Further reducing the pressure in the first adsorption tank through a suction pipe connecting each,
In the pressurized adsorption step, the compressed source air stored in the compressed source air tank is introduced into the aspirator to further reduce the pressure in the second adsorption tank through the suction pipe. , Nitrogen-enriched gas production method.

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