JP2003225526A - Weight reduction operation method for pressure swing adsorption apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a weight reduction operation method for a pressure swing adsorption apparatus capable of reducing the consumption amount of raw material air to the utmost, capable of ensuring a production yield equal to or more than that at the time of usual operation, and capable of achieving the effective conservation of energy. <P>SOLUTION: At the time of weight reduction operation, the transfer from an adsorption process of each adsorption column to a regeneration process thereof is performed through a standby process wherein raw material air and regeneration gas are not supplied without altering an adsorption process time (t), and a cycle time T<SB>1</SB>is extended by the time (w) required in the standby process as compared with a cycle time T<SB>0</SB>at the time of usual operation. The standby process time (w) is set so that the increment of the cycle time T<SB>1</SB>at the time of weight reduction operation to the cycle time T<SB>0</SB>at the time of usual operation is inversely proportional to the decrement of the production quantity of product gas to that at the time of usual operation. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reducing a pressure fluctuation adsorption device.

[0002]

2. Description of the Related Art Pressure fluctuation adsorption device (hereinafter "PSA device")
Means that a pair of adsorption towers filled with an adsorbent that preferentially adsorbs a specific component in the air absorbs the raw material air introduced into the adsorption tower to produce product gas. The product gas is supplied from the adsorption tower in the adsorption process to the gas use part by switching to the regeneration process of supplying the regeneration gas to the subsequent adsorption tower to regenerate the adsorbent at a predetermined cycle time. Has been done.

Therefore, in the PSA apparatus, it is necessary to carry out a reduction operation in accordance with the load fluctuation in the gas use section. For example, when the gas use quantity is reduced at night, the adsorption tower will be operated accordingly. It is necessary to reduce the amount of product gas supplied to the gas use section.

[0004]

By the way, as the adsorbent packed in the adsorption tower, for example, when the product gas is nitrogen, molecular sieve activated carbon which preferentially adsorbs an oxygen component is used. As shown in FIG. 6, the molecular sieve activated carbon has different adsorption rates of an oxygen component and a nitrogen component, and the adsorption amount of the oxygen component is saturated after a lapse of a certain time t0 from the start of the adsorption, and then the adsorption amount of the nitrogen component increases. Has adsorption properties.

Therefore, in order to efficiently perform the adsorption treatment (production of nitrogen gas) using the molecular sieve activated carbon, it is necessary to determine the adsorption process time (adsorption step time) based on the adsorption characteristics of the molecular sieve activated carbon. is necessary. That is, the switching time of the adsorption tower (the cycle time for switching between the adsorption step and the regeneration step) is uniquely determined by the adsorption characteristics of the molecular sieve activated carbon, and is substantially constant regardless of the scale of the PSA device.

However, since the switching time of the adsorption tower cannot be changed in this manner, the rate of decrease in the consumption of raw material air is smaller than the rate of decrease in the amount of product gas produced during the reduction operation. For example, using a molecular sieve activated carbon, a purity of 9
Normal operation (rated operation) when producing 9% nitrogen gas
Then, nitrogen gas can be produced at a ratio of raw material air: nitrogen gas = 1: 0.3 to 0.4, but in a 50% raw material operation, nitrogen is produced at a ratio of raw material air: nitrogen gas = 0.8: 0.2. Gas is produced, and although the production amount of nitrogen gas is reduced to 50% of that during normal operation, the amount of raw material air needs to be 80% of that during normal operation, and the consumption of raw material air is small. To 2
It is only reduced by 0%. That is, the ratio of the production amount of the product gas to the consumption amount of the raw material air in the normal operation (hereinafter referred to as “production yield”) is 0.3 to 0.4, but the production yield is 50% in the reduction operation. It stops at 0.25. As described above, in the reduction operation, the production yield is lower than that in the normal operation, and the consumption of the raw material air with respect to the production amount of the product gas is large, so that it is necessary to compress the raw material air supplied to the adsorption tower. There is a problem that the energy increases and the running cost of the PSA device increases.

The present invention has been made in view of the above points, and it is possible to reduce the consumption of raw material air as much as possible and to secure a production yield equal to or higher than that during normal operation. It is an object of the present invention to provide a weight reduction operation method of a PSA device that can achieve effective energy saving.

[0008]

According to the present invention, a pair of adsorption towers filled with an adsorbent that preferentially adsorbs a specific component in the air is subjected to an adsorption treatment of raw material air introduced into the adsorption tower to produce a product gas. By switching the adsorption step in the adsorption step after the adsorption step and the regeneration step of regenerating the adsorbent by supplying a regeneration gas to the adsorption tower after the adsorption step at a predetermined cycle time, the adsorption tower in the adsorption step is changed to a gas use part. In order to achieve the above-mentioned object in a PSA device that supplies product gas,
When the production amount of the product gas is reduced from the normal operation (rated operation) according to the load of the gas use part, the feed air and the regenerated gas are not supplied during the transition from the adsorption step to the regeneration step in each adsorption tower. By performing through the standby process,
A method for reducing the weight of a PSA apparatus is proposed, which is characterized in that the cycle time is extended without changing the adsorption process time. The cycle time is specifically the time from the time when the adsorption process is started to the time when the regeneration process is started after the end of the adsorption process in one of the adsorption towers (or the regeneration process is started). Time from the end of the regeneration step to the start of the adsorption step).

In such a reduction operation method, it is preferable to set the standby process time so that the increase rate of the cycle time in the normal operation is inversely proportional to the decrease rate of the product gas production amount in the normal operation. That is, the standby process time is (1) when the production amount of product gas is normal operation.
/ X) times, the cycle time is set to be X times or approximately X times that in normal operation (X is 1
Any number above). Further, while one of the adsorption towers is from the start of the adsorption step to the end of the standby step, the other adsorption tower performs the regeneration step by the same regeneration gas supply as in the normal operation, and then the regeneration gas supply is stopped. In this state, it is preferable to perform a decompression regeneration step of opening the adsorption tower to the atmosphere. Further, the weight reduction operation method of the present invention is
It is particularly suitable when the PSA apparatus is a nitrogen gas production apparatus using molecular sieve activated carbon as an adsorbent.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
~ It demonstrates concretely based on FIG.

The PSA apparatus shown in FIGS. 1 to 4 is a nitrogen gas production apparatus, and comprises a pair of adsorption towers 1a and 1b and a raw material air A.
A raw material air supply means 2 for supplying the adsorption air to the adsorption towers 1a and 1b,
Product gas supply means 4 for supplying the product gas (nitrogen) B obtained in the adsorption towers 1a, 1b to the gas use part 3 and regeneration gas supply means 5 for supplying the regeneration gas (nitrogen) C to the adsorption towers 1a, 1b. A regeneration gas purge means 6 for releasing the regeneration gas C from the adsorption towers 1a, 1b into the atmosphere, and the adsorption towers 1a, 1b.
It is provided with a pressure equalizing means (pressure equalizing passages 7, 8 and pressure equalizing valves 71, 81) for uniformly adjusting the pressure of 1b.

Each of the adsorption towers 1a, 1b is filled with a molecular sieve activated carbon 9 which is an adsorbent which preferentially adsorbs oxygen components in the air, and the raw material air A introduced from the lower part thereof is adsorbed and treated. The nitrogen gas B, which is a product gas, is led out from the upper portion.

The raw air supply means 2 is an air compressor 20.
And the raw material air supply line 21 led from the air compressor 20
And a first conduit 22 branched from the downstream end of the raw material air supply conduit 21 and connected to the lower part of one adsorption tower (hereinafter referred to as “first adsorption tower”) 1a and the other adsorption tower (hereinafter referred to as “ Second
2nd pipe line 23 connected to the lower part of 1b)
And the first and second on-off valves 26 and 27.
An air dryer built-in type (pressure: 0.69 MPa) is used as the air compressor 20. A mist separator 24 and a flow meter 25 are provided in the raw material air supply pipeline 21.
Is provided. First and second opening / closing valves 26, 27 are provided in the first and second pipelines 22, 23. Thus, according to the raw material air supply means 2, the first or second on-off valves 26 and 27 are opened to be compressed and dehumidified by the air compressor 20 and cleaned by the mist separator 24 (dust and oil content). The removed material air A is the first
Alternatively, it is supplied to the second adsorption towers 1a and 1b.

The product gas supply means 4 has a buffer tank 40, a flow meter 41 and a flow rate control valve (automatic valve) 42 at its downstream end.
Product gas supply line 43 led to the gas use part 3 via
And a third conduit 44 and a second conduit 44 branched from the upstream end of the product gas supply conduit 43 and connected to the upper part of the first adsorption tower 1a.
The fourth conduit 45 connected to the upper part of the adsorption tower 1b, and the third and fourth conduits 44, 45 are provided to provide the adsorption towers 1a, 1b.
First and second check valves 46, 47 for preventing backward flow in the direction
And. Thus, according to the product gas supply means 4, the product gas A discharged from the first or second adsorption tower 1a, 1b passes through the third or fourth conduits 44, 45 and the product gas supply conduit 43. Is supplied to the buffer tank 40.

The regeneration gas supply means 5 is branched from a regeneration gas supply pipeline 51 whose upstream end is connected to an upstream side portion of the buffer tank 40 in the product gas supply pipeline 43 and a downstream end of the regeneration gas supply pipeline 51. A fifth conduit 52 connected to the upper part of the first adsorption tower 1a, a sixth conduit 53 connected to the upper part of the second adsorption tower 1b, and third and fourth check valves 54, 5
5 and a third opening / closing valve 58. 5th and 6th
The downstream side portions of the pipe lines 52, 53 (portions connected to the adsorption towers 1a, 1b) are upstream side portions (first and second pipe lines) of the third and fourth pipe lines 44, 45 of the product gas supply means 4. Check valve 4
6, 47, and the adsorption towers 1a, 1b side portions). In the upstream side portion of the fifth and sixth pipelines 52, 53 (the portion that is connected to the regeneration gas supply pipeline 43 and is not configured to be shared by the third and fourth pipelines 44, 45) Is provided with third and fourth check valves 54 and 55 that prevent a reverse flow in the direction of the regeneration gas supply line 43. A flow meter 56, a flow rate control valve (needle valve) 57, and a third opening / closing valve 58 are provided in the regeneration gas supply pipeline 51. Thus, according to the regeneration gas supply means 5, the product gas B supplied from the product gas supply pipeline 43 to the buffer tank 40 by opening the third opening / closing valve 58.
Part (nitrogen gas) of the regenerated gas C from the regenerated gas supply pipe line 51 via the fifth or sixth pipe lines 52, 53
Alternatively, it is supplied to the second adsorption towers 1a and 1b.

The regeneration gas purging means 6 is the first adsorption tower 1a.
Pipe line 61 connected to the lower part of the second adsorption tower 1b, eighth pipe line 62 connected to the lower part of the second adsorption tower 1b, and seventh and eighth pipe lines 6
It is provided with a discharge pipe line 63 that is connected to the downstream ends of 1, 62 and is open to the atmosphere, and fourth and fifth opening / closing valves 64, 65. The upstream side portions of the seventh and eighth pipelines 61 and 62 (portions connected to the adsorption towers 1a and 1b) are downstream portions of the first and second pipelines 22 and 23 of the raw material air supply means 2 ( First
And the portions on the adsorption towers 1a, 1b side of the second opening / closing valves 26, 27). 7th and 8th pipeline 6
The fourth and fifth on-off valves are provided in the downstream side portions of 1, 62 (portions that are connected to the discharge pipeline 63 and are not commonly configured by the first and second pipelines 22, 23). 6
4, 65 are provided. Thus, according to the regeneration gas purging means 6, the regeneration gas C supplied to the first or second adsorption towers 1a, 1b is changed to the seventh or the seventh by opening the fourth or fifth opening / closing valves 64, 65. It is adapted to be discharged into the atmosphere from the discharge conduit 63 via the eighth conduits 61 and 62.

The pressure equalizing means is composed of first and second pressure equalizing passages 7 and 8 connecting the upper and lower portions of both adsorption towers 1a and 1b, and sixth and seventh opening and closing as pressure equalizing valves provided therein. Valve 71,
And 81. The adsorption tower side portions of the first and second pressure equalizing passages 7 and 8 are the adsorption tower side portions of the third and fourth pipelines 44 and 45 (or the fifth and sixth pipelines 52 and 53) and the adsorption tower side portions. 1st and 2nd pipeline 22,23 (or 7th and 8th pipeline 6
1, 62) is also configured to be used on the side of the adsorption tower. Thus, according to the pressure equalizing means, the sixth and seventh on-off valves 71, 81
By opening the column, both adsorption towers 1a and 1b can be communicated with each other so that a uniform pressure can be achieved.

Therefore, during normal operation, as shown in FIG.
As shown in (A), the adsorption towers 1a and 1b are switched at a constant cycle time T ₀ , and the adsorption step, the pressure equalization step, and the regeneration step are successively performed.

First, one adsorption tower, for example, the first adsorption tower 1
a starts the adsorption process and is the other adsorption tower
The adsorption tower 1b starts the regeneration process, and this process is continued for a fixed time (adsorption process time t). That is, as shown in FIG. 1, the first, third and fifth on-off valves 26, 58 and 65 are opened, and the other on-off valves 27, 64, 71 and 81 are closed, and the raw material air A is fed into the raw material air A. It is supplied to the first adsorption tower 1a from the air supply pipeline 21 and the first pipeline 22. First adsorption tower 1a
The raw material air A supplied to the adsorbent 1a has its oxygen component adsorbed and removed by the adsorbent (molecular sieve activated carbon) 9 packed in the adsorption tower 1a, and is discharged from the upper portion of the adsorption tower 1a as a product gas (nitrogen) B. Third pipeline 44 and product gas supply pipeline 4
3 is supplied to the buffer tank 40. The time (adsorption step time) t during which the adsorption step is performed is set on condition that the adsorption characteristics of the adsorbent 9 described at the beginning are exhibited to the maximum extent. On the other hand, in the second adsorption tower 1b,
A part of the nitrogen gas B produced in the first adsorption tower 1b is supplied as the regeneration gas C from the regeneration gas supply pipeline 51 and the sixth pipeline 53, and the second adsorption tower 1b is supplied to the fifth pipeline 62. Also, the adsorbent 9 which is opened to the atmosphere through the discharge pipe line 63 and is filled in the second adsorption tower 1b is regenerated. In addition,
1 to 4, for convenience, the on-off valve in the closed state is painted black to distinguish it from the on-off valve in the open state.

When the adsorption process by the first adsorption tower 1a is completed, the on-off valve 2 in the open state as shown in FIG.
6, 58, 65 are switched to the closed state, and the first adsorption tower 1a
The supply of the raw material air A to the second adsorption tower 1b and the supply of the regeneration gas C to the second adsorption tower 1b are stopped, and the sixth and seventh on-off valves 71,
By opening 81, both adsorption towers 1a and 1b are transferred to the pressure equalizing step. That is, the first adsorption tower 1a in the high pressure state and the second adsorption tower 1b in the low pressure state are communicated with each other through the pressure equalizing paths 7 and 8 to equalize the pressures of the adsorption towers 1a and 1b. At this time, the concentrated nitrogen remaining in the upper portion of the first adsorption tower 1a flows into the second adsorption tower 1b from the first pressure equalizing passage 7,
Smooth the transition of the adsorption tower 1b to the adsorption step.

When the pressure equalizing step is completed, the pressure equalizing passages 71 and 81 are shut off and the second to fourth on-off valves 27, 58 and 65 are opened, as shown in FIG. Tower 1
A is switched to the regeneration step and the second adsorption tower 1b is switched to the adsorption step, and the adsorption step and the regeneration step similar to the above are performed. After that, the switching of the adsorption towers 1a and 1b is repeatedly performed at a constant cycle time T ₀ , and the product gas B is continuously produced.

When the amount of gas used in the gas use unit 3 is smaller than that during normal operation, the PSA device is reduced in amount according to the present invention as follows.

In the reduction operation, as shown in FIG. 5 (B), the adsorption process is shifted to the pressure equalizing process and the regeneration process through the standby process, and the adsorption process time t is the same as that in the normal operation. However, the switching time of the adsorption towers 1a and 1b, that is, the cycle time T ₁ is the cycle time T ₀ during normal operation.
It will be extended depending on the weight loss.

That is, in one adsorption tower, for example, the first adsorption tower 1a, after the adsorption step shown in FIG. 1 has been performed for the same time t as in the normal operation, the first opening / closing valve 2 as shown in FIG.
6 is switched to the closed state, and the process shifts to the standby step in which the supply of the raw material air A to the first adsorption tower 1a and the production of the product gas B by the adsorption tower 1a are stopped. The time (standby process time) w for performing the standby process is set such that the increase rate of the cycle time T ₁ including the standby process with respect to the normal operation cycle time T ₀ is substantially inversely proportional to the decrease rate of the product gas production amount during the normal operation. That is, the cycle time T ₁ is set to be X times (or approximately X times) the normal operation cycle time T ₀ when the product gas production amount is (1 / X) times the normal operation time. .

When the standby process time w thus set has elapsed, the first adsorption tower 1a ends the standby process and shifts to the pressure equalizing process shown in FIG. Further, the process proceeds to the regeneration process shown in FIG.

As described above, in the reduction operation, since the production of the product gas B is stopped for a predetermined time (standby step time) w according to the reduction amount, the production amount of the product gas with respect to the consumption of the raw material air A is reduced. The production yield, which is a ratio, is equal to or higher than that in normal operation. In other words, the consumption amount of the raw material air A is significantly reduced as compared with the case where the standby process is not provided. Therefore, the air compressor 20
Load is reduced, energy saving and running cost reduction are achieved.

On the other hand, the second adsorption tower 1b which is the other adsorption tower
In the process from the start of the adsorption process to the end of the standby process in the first adsorption tower 1a, first, as shown in FIG. 1, the regeneration process is performed by supplying the regeneration gas C as in the normal operation, Then, as shown in FIG.
8 is switched to the closed state, and the supply of the regeneration gas C to the second adsorption tower 1b is stopped, and the depressurization regeneration step of opening the adsorption tower 1b to the atmosphere is started. That is, in the reduced pressure regeneration step, the lower part of the second adsorption tower 1b is the eighth conduit 6
Although it is opened to the atmosphere via 2 and the release pipe line 63, the regeneration process of the adsorbent 9 in the adsorption tower 1b proceeds only by opening to the atmosphere without supplying the regeneration gas C. Therefore, by performing the reduced pressure regeneration step in addition to the normal regeneration step, the degree of regeneration of the adsorbent becomes higher than that during normal operation, and the subsequent adsorption treatment can be performed more effectively, and the production yield can be further improved. Can be improved. In particular, when the adsorbent 9 has a low adsorption rate and a low desorption rate (regeneration rate), the effect of the addition of the reduced pressure regeneration step is remarkable. The regeneration process by supplying the regeneration gas C is usually performed for the same time as during normal operation (adsorption process time t), and the transition time from the regeneration process to the decompression regeneration process is set to the transition time from the adsorption process to the standby process. Although they are matched, depending on the adsorption conditions such as the properties of the adsorbent 9,
It is also possible to deviate from these transition timings (for example, the transition timing from the regeneration step to the reduced pressure regeneration step may be earlier than the transition timing from the adsorption step to the standby step).

When the first adsorption tower 1a shifts from the standby step to the pressure equalization step, the second adsorption tower 1b also shifts from the decompression regeneration step to the pressure equalization step, and after that, the adsorption towers 1a and 1b.
Is switched at the extended cycle time T ₁ described above to perform each of the above steps, but the cycle time T _1, that is, the waiting step time w is increased or decreased in accordance with the reduction amount.

The present invention is not limited to the above-described embodiments, but can be appropriately improved and changed without departing from the basic principle of the present invention. For example, in the above-described embodiment, the regeneration gas supply pipe line 51 is connected to the product gas supply pipe line 43 upstream of the buffer tank 40, and a part of the product gas B toward the buffer tank 40 is used as the regeneration gas C. However, when a part of the product gas B is used as the regeneration gas C, the connection point of the regeneration gas supply pipe 51 (reproduction gas C sampling point) and the source of the regeneration gas C are selected. It is optional depending on the configuration and usage conditions of the PSA device. Further, in the above-described embodiment, the present invention is applied to the PSA apparatus for nitrogen gas production using the molecular sieve activated carbon as the adsorbent 9, but the present invention preferentially adsorbs the nitrogen component as the adsorbent. The present invention can also be applied to a PSA apparatus for oxygen gas production using zeolite or the like.

[0030]

EXAMPLE As an example, the above PSA apparatus was used to perform a normal operation with a cycle time of 96 seconds and a cycle time of 146 seconds (standby step time w: 5
0 seconds) and 296 seconds (standby step time w: 200 seconds), two types of reduction operations A and B (both the adsorption step time t is the same as the normal operation) are performed, and the reduction air consumption amount in each case And the production yield was determined from the nitrogen production amount. The results are as shown in Table 1.

As a comparative example, a normal operation and a weight reduction operation a and b are performed under the same conditions as those of the embodiment except that the standby process is not provided (standby process time: w = 0). The production yield was calculated from the reduced air consumption and nitrogen production in the above. The results are shown in Table 2. In any case, the adsorption step time t and the cycle time are the same as in the normal operation of the embodiment. In addition, the weight reduction operation a
The nitrogen production amount in 1 is the same as that in the reduction operation A, and the nitrogen production amount in the reduction operation b is the same as that in the reduction operation B.

As shown in Table 1, the production yield of the example was 0.339 in normal operation. Then, in the reduction operation A in which the cycle time was extended to 146 seconds, the production yield was 0.362, which was higher than the production yield in the normal operation. Furthermore, the cycle time is 296
In the weight reduction operation B extended to 2 seconds, the production yield was 0.411, which greatly exceeded the production yield in the normal operation.

On the other hand, in the comparative example, as shown in Table 2, the production yield in the normal operation is naturally the same as that in the normal operation of the example (production yield: 0.33).
9), the production yield was 0.27 in the reduction operation a.
It was 0, which was lower than the production yield in normal operation. Further, in the reduction operation b, the production yield was 0.183, which was significantly lower than the production yield in the normal operation.

From these facts, according to the general reduction operation method at the beginning, which has the same cycle time as in the comparative example, the production yield is lower than that in the normal operation, and the production yield further increases as the reduction amount increases. However, according to the weight reduction operation method of the present invention, as in the example, the production yield does not decrease from that during normal operation, and it is possible to ensure a production yield equal to or higher than that during normal operation. It is understood that the production yield increases as the degree of weight loss increases, contrary to the general weight loss operation method.

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

As can be understood from the above description, according to the reduction operation method of the present invention, the production yield (equal to the production amount of product gas relative to the consumption amount of raw material air) equal to or higher than that during normal operation can be obtained. Ratio) can be secured, the consumption of raw material air can be reduced as much as possible, and energy saving and running cost reduction of the PSA device can be achieved.

[Brief description of drawings]

FIG. 1 is a system diagram of a PSA apparatus showing a state in which a first adsorption tower is in an adsorption step and a second adsorption tower is in a regeneration step.

FIG. 2 is a view corresponding to FIG. 1 showing a state where the first adsorption tower is in a standby process and the second adsorption tower is in a regeneration process.

FIG. 3 is a view corresponding to FIG. 1 showing a state where both adsorption towers are in a pressure equalizing step.

FIG. 4 is a view corresponding to FIG. 1, showing a state in which the first adsorption tower is switched to the regeneration step and the second adsorption tower is switched to the adsorption step.

FIG. 5 is a process diagram showing a mode of switching processes,
The figure (A) shows the normal operation, and the figure (B) shows the reduction operation.

FIG. 6 is a curve diagram showing adsorption characteristics of molecular sieve activated carbon.

[Explanation of symbols]

1a, 1b ... Adsorption tower, 2 ... Raw material air supply means, 3 ... Gas use part, 4 ... Product gas supply means, 5 ... Regeneration gas supply means, 6 ... Regeneration gas purging means, 7, 8 ... Pressure equalizing path (equalizing pressure) Means), A ... Raw material air, B ... Product gas (nitrogen gas), C ...
Regeneration gas (nitrogen gas).

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[Procedure amendment]

[Submission date] February 5, 2002 (2002.2.5)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Title of invention

[Correction method] Change

[Correction content]

[Title of Invention] Method for reducing pressure of pressure fluctuation adsorption device ────────────────────────────────────── ────────────────

[Procedure amendment]

[Submission date] February 5, 2002 (2002.2.5)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0036

[Correction method] Change

[Correction content]

[0036]

[Table 2]

Claims (4)

[Claims] 1. An adsorption step and an adsorption step in which a pair of adsorption towers filled with an adsorbent that preferentially adsorbs a specific component in the air is adsorbed with raw air introduced into the adsorption tower to produce a product gas. The product gas is supplied from the adsorption tower in the adsorption step to the gas use part by switching to a regeneration step of supplying the regeneration gas to the adsorption tower after the completion to regenerate the adsorbent at a predetermined cycle time. In the pressure fluctuation adsorption device, when the production amount of the product gas is reduced from the normal operation according to the load of the gas use part, the feed air and the regenerated gas are supplied from each adsorption tower to the transition from the adsorption process to the regeneration process. The method for reducing the pressure fluctuation adsorption device is characterized in that the cycle time is extended without changing the adsorption process time by performing the operation through a standby process not performed. 2. The standby process time is set so that the increase rate of the cycle time with respect to the normal operation is inversely proportional to the decrease rate of the product gas production amount with respect to the normal operation. 1. The method for reducing the pressure fluctuation adsorption device described in 1. 3. During one of the adsorption towers from the start of the adsorption step to the end of the standby step, the other adsorption tower performs the same regeneration gas supply as in the normal operation and then the regeneration gas supply. The method for reducing the pressure fluctuation adsorption device according to claim 1 or 2, wherein a depressurization regeneration step of opening the adsorption tower to the atmosphere is performed in a state where the pressure fluctuation adsorption device is stopped. 4. The pressure fluctuation adsorption device according to claim 1, wherein the pressure fluctuation adsorption device is a nitrogen gas production device using molecular sieve activated carbon as an adsorbent. Weight loss driving method.