JPH04305217A - Gas adsorbing and separating device and method - Google Patents

Abstract

PURPOSE:To provide the gas adsorbing and separating device and method which eliminates the fluctuation in the supply pressure and flow rate of a refined gas at the time of a regeneration stage and can make stable operation of a process using the refined gas. CONSTITUTION:The gas adsorbing and separating device which executes purging or pressure charging of adsorption column by successively changing over the plural adsorption columns A, B to an adsorption stage and a regeneration stage and introducing a part of the refined gas in a refined gas leading out route T to the adsorption column in the purging or pressure charging stage during the regeneration stage is provided with a flow rate detector 14a which detects the flow rate of the refined gas to be used for the purging or pressure charging in a pressure charging gas introducing route U. Flow rate computing parts 15, 16 and a setter 17 which operate on the detected value of the flow rate detector 14a are provided in order to control the supply rate of the gaseous raw material of a gaseous raw material supply route S and the flow rate of the gaseous raw materials is controlled by a flow rate indicating controller 11.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas adsorption separation apparatus and method, and more particularly to a gas adsorption separation apparatus and method suitable for use in raw air purification.

0002

[Prior Art] Gas adsorption separation devices are used to purify specific components in gases, such as moisture and carbon dioxide gas in the feed air, for example, gas adsorption separation devices used to purify raw air in the air liquefaction separation device mentioned above. The raw air is purified by sequentially switching a plurality of adsorption towers filled with the agent to an adsorption (purification) process and a regeneration process.

[0003] The above regeneration process differs depending on the configuration of the equipment, but in the case of a pressure fluctuation type, there is usually a pressure relief stage in which the gas in the adsorption tower is released, and a part of the purified gas is introduced into the adsorption tower from the opposite direction. The adsorbent is regenerated by performing a purge stage in which the inside of the column is purged, and a pressurizing stage in which a part of the purified gas is introduced into the adsorption tower and the pressure inside the tower is raised to the adsorption pressure. In addition, in the case of temperature difference re-formulation, there is a pressure release stage in which the gas in the adsorption tower is released, a heating regeneration stage in which heated gas is introduced into the adsorption tower from the opposite direction to heat and regenerate the adsorbent, and a heating regeneration stage in which the adsorbent is heated to the adsorption temperature. There is a cooling stage in which a portion of the purified gas is cooled down to the adsorption tower, and a charging stage in which a portion of the purified gas is introduced into the adsorption tower and the pressure inside the tower is increased to the adsorption pressure.

0004

[Problems to be Solved by the Invention] In the adsorption separation device that performs the regeneration process as described above, a part of the purified gas is used in the purging stage and the charging stage, so it is difficult to use the purified gas in the process that uses the purified gas. The flow rate and pressure of the supplied gas will fluctuate. Therefore, if the above process is an air liquefaction separation device, stable operation of the rectification column, condenser, etc. may be hindered, and product purity may be affected.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a gas adsorption separation apparatus and method that can eliminate fluctuations in the purified gas supply pressure and flow rate during the regeneration step and ensure stable operation of a process using purified gas.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the gas adsorption separation apparatus of the present invention includes a plurality of adsorption towers that are sequentially switched to an adsorption process and a regeneration process, and a raw material to an adsorption tower that is in the adsorption process. A raw material gas supply route for supplying gas, a purified gas derivation route for deriving purified gas after separation from the adsorption tower, and a purified gas derivation route in the purified gas derivation route to the adsorption tower in the purge stage or pressurization stage during the regeneration process. A gas adsorption separation device equipped with a pressurized gas introduction path that introduces a portion of the gas to purge or pressurize the adsorption tower, and a plurality of switching valves that sequentially switch the plurality of adsorption towers to an adsorption process and a regeneration process. A flow rate detector for detecting the flow rate of purified gas used for purging or charging is provided in the pressurized gas introduction path, and a flow rate detector for detecting the flow rate of purified gas used for purge or pressurization is provided in the raw material gas supply path based on the detected value of the flow rate detector. It is characterized by being equipped with a flow rate controller that controls the supply amount.

In addition, in the gas adsorption separation method of the present invention, a raw material gas is introduced into a plurality of adsorption towers that are switched and used, a specific component gas is separated and purified by adsorption separation, a product gas is taken out, and a part of the product gas is In the method of operating a gas adsorption separation device in which the product gas is used as purge gas and/or charging gas in the regeneration process, during the purge and/or charging stage with the product gas during the regeneration process, the purge gas and/or the charging gas is It is characterized by detecting the flow rate and controlling the flow rate of the raw material gas at the entrance of the adsorption tower.

[0008]

[Operation] According to the above configuration, the amount of purified gas can be increased by increasing the supply amount of raw material gas according to the flow rate of purified gas used for purging or charging, so purified gas can be used from the gas adsorption separation device. The flow rate and pressure of purified gas supplied to the process can be kept constant.

[0009]

EXAMPLE Hereinafter, the present invention will be explained in more detail based on an example in which the present invention is used for purifying raw air in an air liquefaction separation device.

The gas adsorption separation apparatus shown in this embodiment has two adsorption towers A and B filled with a predetermined adsorbent. , a compressor 1, a check valve 2, and inlet valves 3a and 3b are provided, and a purified gas derivation path T for deriving purified gas is provided with outlet valves 4a and 4b. In addition, for the regeneration of the adsorption towers A and B, exhaust valves 5a and 5b are provided for releasing and exhausting the gas in the adsorption towers A and B, and heated gas and adsorbent for heating and regenerating the adsorbent are heated to the adsorption temperature. Regeneration valves 6a and 6b that introduce cooling gas to cool down to 7 and charging valves 8a and 8b for switching the introduction direction are provided.

[0011] In this gas adsorption separation apparatus, like the conventional apparatus, for example, when one of the adsorption towers A is in the adsorption process, the inlet valve 3a and the outlet valve 4a are opened and the raw material gas, for example, the raw air, is transferred to the adsorption tower A. The purified gas is led out to the supply pipe 9.

At this time, the other adsorption tower B is in the regeneration process, and with the inlet valve 3b and outlet valve 4b closed, the exhaust valve 5b is first opened to exhaust the gas in the tower and increase the pressure. lower to atmospheric pressure. Next, the regeneration valve 6b is opened, and heated gas heated to a predetermined temperature by a heater (not shown) is introduced into the adsorption tower B from the opposite direction to perform heating regeneration of the adsorbent. When the heating regeneration is completed, low temperature gas is introduced from the regeneration valve 6b while the valve state remains unchanged, and the adsorbent in the adsorption tower B is cooled to the adsorption temperature. After cooling, when the exhaust valve 5b and the regeneration valve 6b are closed, the flow rate control valve 7 and the pressure filling valve 8b are opened and a predetermined amount of purified gas is introduced into the adsorption tower B, and the adsorption operating pressure inside the tower is increased.
For example, the charging pressure is increased to 5 kg/cm2G.

When the above-mentioned charging is completed, the inlet valve 3a and the outlet valve 4a are closed, the inlet valve 3b and the outlet valve 4b are opened, and the adsorption tower B enters the adsorption process, and the adsorption tower A enters the regeneration process.

[0014]The raw material gas supply path S is provided with a suction port of the compressor 1 as an adjustment means for adjusting the flow rate and pressure of the gas supplied from the outlet valves 4a and 4b to the subsequent process through the supply pipe 9. A guide vane 10 that adjusts the flow rate, a flow rate indicating controller 11 that controls the guide vane 10 according to the discharge flow rate of the compressor 1, and a pressure indicating regulator that opens and closes the discharge valve 12 according to the discharge pressure of the compressor 1. A total of 13 is provided in the charging gas introduction path U, and a flow rate indicating controller 14 that controls the flow rate regulating valve 7 according to the detected value of the flow rate detector 14a that detects the flow rate of the product gas for charging. Further, in order to prevent fluctuations in the flow rate of purified gas during the pressurization, flow rate calculators 15 and 16 and a setting device are provided to control the supply amount of the raw material gas based on the detected value of the flow rate detector 14a. 17 are provided.

[0015] The flow rate calculators 15 and 16 and the setting device 17
The flow rate calculator 15 converts the flow rate signal of the product gas for pressurization into a flow rate control signal for the compressor 1, and the flow rate calculator 16 converts the flow rate signal of the product gas for charging into a flow rate control signal for the compressor 1 based on the set value set in the setting device 17. It is configured to output a flow rate correction signal to.

That is, when a part of the product gas is introduced into either adsorption tower A or B from one of the filling valves 8a and 8b,
The flow rate detector 14a measures the flow rate of the product gas used for charging, and the flow rate calculator 15 converts this flow rate signal into a value suitable for the instrument scale of the flow rate indicator controller 11 of the compressor 1. 17 sets an increase in the amount of raw material gas based on the ratio of the amount of raw material gas to the amount of product gas, and the flow rate calculator 16 adds this increased amount to the current setting value of the flow rate indicator controller 11. As a result, the flow rate indicating controller 11 is set to the guide vane 1.
0 and increase the amount of raw material gas. For example, purified gas 10
If 110 parts of raw material air is required for 0 parts, if 10 parts is used as the filling gas, the amount of raw material gas will be increased by 11 parts.

Therefore, even if a part of the product gas is used for pressurization in the pressurization stage and the amount of purified gas supplied from the supply pipe 9 is reduced, the flow rate detector 14a and the flow rate calculators 15, 16 , the setting device 17, and the flow rate indicating controller 11 operate to increase the amount of raw air, and the purified gas is purified in the adsorption towers A and B and supplied to the subsequent process from the outlet valves 4a and 4b via the supply pipe 9. The amount can be maintained at a constant level, the operation of subsequent processes such as air liquefaction separation equipment can be stabilized, and accidents such as deterioration of product purity can be prevented.

In the above embodiment, the gas adsorption separation device of the present invention is applied to air purification used in the pretreatment equipment of an air liquefaction separation device, and is operated in a temperature difference regeneration system. The present invention can be similarly applied to other gas adsorption separation devices that require a constant gas flow rate, regardless of the number of adsorption towers or regeneration method.

[0019]

[Effects of the Invention] As explained above, according to the present invention,
Since the flow rate of purified gas can always be kept constant, it is possible to ensure stable operation of subsequent processes.For example, in air liquefaction separation equipment, various processes after this purification process, such as rectification processes, can be performed stably. This allows product purity to be maintained within a certain range.

In particular, in the present invention, since the flow rate of the raw material gas is controlled by detecting the flow rate of the purified gas used for charging, the flow rate of the raw material gas is controlled based on the process time or the flow rate of the purified gas supply path is detected. It has excellent accuracy and response speed, and can perform reliable control.

[Brief explanation of drawings]

FIG. 1 is a system diagram of a gas adsorption separation device showing an embodiment of the present invention.

[Explanation of symbols]

1... Compressor 3a, 3b... Inlet valve 4a,
4b...Outlet valve 5a, 5b...Exhaust valve 6a, 6b...Regeneration valve 7...Flow control valve 8a, 8b...Pressure valve 9...Supply pipe 10...Guide vane 11...
Flow rate indicating controller 14...Flow rate indicating controller 14a...Flow rate detector 15,1
6... Flow rate calculator 17... Setting device A, B... Adsorption tower S... Raw material gas supply route
T...Purified gas lead-out route U...Purified gas introduction route

Claims (2)

[Claims] Claim 1: A plurality of adsorption towers that are sequentially switched to an adsorption step and a regeneration step, a raw material gas supply route that supplies raw material gas to the adsorption tower in the adsorption step, and a purified gas after separation from the adsorption tower. A part of the purified gas in the purified gas derivation path is introduced into the purified gas derivation path and the adsorption tower in the purge stage or pressurization stage during the regeneration process to purge or pressurize the adsorption tower. In a gas adsorption separation device equipped with a passage and a plurality of switching valves that sequentially switch a plurality of adsorption towers to an adsorption process and a regeneration process, the flow rate of purified gas used for purging or charging is added to the pressurized gas introduction route. A gas adsorption separation device characterized in that a flow rate detector is provided to detect the flow rate, and a flow rate controller is provided in the source gas supply path to control the supply amount of the source gas based on the detected value of the flow rate detector. . [Claim 2] A raw material gas is introduced into a plurality of adsorption towers that are used selectively to separate and purify specific component gases by adsorption separation, and a product gas is taken out, and a part of the product gas is used as a purge gas for the regeneration process and/or In a gas adsorption separation method using the gas as a charging gas, the flow rate of the purge gas and/or the charging gas is detected during the purging and/or charging stage with the product gas during the regeneration process, and the flow rate of the raw material gas at the entrance of the adsorption tower is detected. A gas adsorption separation method characterized by controlling the flow rate.