JPH0568835A - Gas separator - Google Patents

Abstract

PURPOSE:To provide a pressure-swinging adsorption-type gas separator capable of continuously separating gases without lowering the concn. of a refined gas by providing a means for switching an adsorption stage to a regeneration stage in accordance with the supply of the gas to be separated to an adsorption tower. CONSTITUTION:Two adsorption towers 7 and 8 are alternately subject to a pressure adsorption stage and a counter-current reduced-pressure desorption stage by a four-way rotary valve 6 in a pressure-swinging adsorption-type gas separator. In this case, the valve 6 is connected to a motor 2 for driving a booster pump 1 provided to a pipe 15 for introducing a gas to be treated through a reduction gear 4, the valve 6 is driven in accordance with the amt. of the gas to be separated, and the stages are switched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure swing adsorption type gas separator, which is suitable for a method of separating oxygen and nitrogen from air.

[0002]

2. Description of the Related Art FIG. 4 is an explanatory view of a conventional pressure swing adsorption type gas separation apparatus for air separation. The air, which is the gas to be treated, is pressurized by the air pump 1 and the five-way solenoid valve 6 '
Is introduced into the adsorption tower 7 or 8 in the adsorption step, nitrogen in the air is adsorbed by the nitrogen adsorbent in the adsorption tower, and the concentrated oxygen gas 18 is supplied via the check valve 10.
To collect. On the other hand, the adsorption tower 8 or 7 in the regeneration process is
The nitrogen which is in communication with the exhaust system 16 at atmospheric pressure through the five-way solenoid valve 6'and is adsorbed in the adsorption tower is desorbed under reduced pressure and discharged to the exhaust system 16. Switching between the pressure adsorption process and the decompression desorption regeneration process is performed by energizing the electromagnetic coil and driving the five-way solenoid valve 6 '. The air pump 1 is driven by a motor 2, and a cooling fan 3 is attached to the motor 2.

[0003]

In the above gas separation apparatus of the pressure adsorption / decompression desorption regeneration system, a five-way solenoid valve is provided on the gas supply side of the adsorption tower as a gas flow switching means, and a sequencer is provided. The five-way solenoid valve is controlled by a timer, a microcomputer, etc., and is switched at regular intervals. In this method, if the voltage changes during operation, the capacity of the air pump will fluctuate regardless of whether it is an AC motor or a DC motor.For example, if the voltage drops, the outlet pressure of the air pump will drop, so the amount of air supplied However, there was a problem that the inside of the adsorption tower could not be raised to a predetermined pressure within a certain period of time, and the oxygen concentration of the product gas decreased. Therefore, the present invention solves the above-mentioned problems and replaces the adsorption / regeneration with a switching method at regular time intervals using a sequencer, a timer, a microcomputer, etc., and regenerates the adsorption tower after a predetermined pressure is reached. An object of the present invention is to provide a pressure swing adsorption type gas separation device which can be switched to a process and can avoid a decrease in product gas concentration.

[0004]

According to the present invention, one end of each of two adsorption towers is connected to a four-way rotary valve, and the other end is connected to a product gas exhaust pipe for non-adsorbed components through a check valve. By connecting, and the rotary valve is connected to the treated gas introduction pipe provided with a pressurizing pump and the desorption gas exhaust pipe of the adsorbed component, by driving the rotary valve,
In a pressure swing adsorption-type gas separation device in which two adsorption towers are alternately switched between a pressure adsorption step and a depressurized desorption regeneration step, the pressurizing pump drive motor of the gas to be treated introduction tube is driven through a speed reducing means. And a gas separation device connected to the four-way rotary valve. As the deceleration means, for example, a drive gear provided on the shaft of the motor and a reduction gear provided on the shaft of the rotary valve can be engaged with each other. Is set by selecting the number of teeth of both.

[0005]

The operation of the present invention will be described below by taking the case of recovering oxygen from air as an example. In the adsorption tower regenerated at atmospheric pressure, the flow path is switched by the four-way rotary valve, the air pressurized by the air pump is introduced, and nitrogen gas is adsorbed by the adsorbent while the pressure inside the adsorption tower is increased. The non-adsorbed oxygen gas is concentrated and collected through the check valve. The adsorption tower switched from the adsorption step to the regeneration step is connected to an exhaust system at atmospheric pressure via a four-way rotary valve, and the adsorbed nitrogen gas is desorbed under reduced pressure and discharged.

In the gas separation apparatus of the present invention, since the four-way port rotary valve is connected through the reduction gear of the air pump motor and the drive gear on the rotary valve side, the air supply amount of the air pump and the four-way port are connected. The rotation angle of the rotary valve can be made proportional, and if the reduction ratio of the gear is set appropriately, the switching of the four-way port rotary valve can be completed when a predetermined amount of air is supplied. According to this method, even if the rotation speed of the air pump changes due to fluctuations in voltage, etc., the four-way port rotary valve can be switched according to the amount of air supplied, so the final pressure of the adsorption process is set to a predetermined value. Therefore, it is possible to avoid a decrease in the concentration of oxygen recovered. Although the case where oxygen is recovered from air has been described above as an example, the present invention can be applied to gas separation other than air, and the same effects as described above can be obtained.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an overall view of a pressure swing adsorption type gas separation device, FIG. 2 is a sectional view of a four-way port rotary valve, and FIG. 3 is an enlarged view showing the relationship between a motor for a pressure pump and a four-way port rotary valve. is there. The air to be treated is the suction pipe 12
It is taken in by the air pump 1, pressurized, and fed into the four-way rotary valve 6 via the pump outlet pipe 13. The four-way rotary valve 6 has four openings as shown in FIG. 2 and a rotor having a structure in which two adjacent openings communicate with each other. A reduction gear 5 is attached to the shaft of the rotor, and a drive gear 4 is attached to the shaft of the air pump motor 2 as shown in FIG. 3. By engaging the reduction gear 5 with the drive gear 4, Since the driving force of the pump motor 2 is decelerated and transmitted to the four-way rotary valve 6, the air pump 1 and the four-way rotary valve 6 rotate together. In other words, the four-way rotary valve 6 is always rotating while the air pump 1 is operating. Then, by appropriately selecting the number of teeth of the drive gear 4 and the reduction gear 5 to determine the reduction ratio,
The switching timing of the four-way port rotary valve 6 can be determined according to the supply air amount.

In the state of FIG. 1, the outlet pipe 13 of the air pump 1 is connected to the conduit 14 of the adsorption tower 7, the air pressurized by the air pump 1 is introduced into the adsorption tower 7, and the granular nitrogen in the tower is introduced. Nitrogen gas in the air is adsorbed by the adsorbent 9, and oxygen gas which is a non-adsorbed component is recovered as concentrated oxygen gas 18 from the outlet pipe 17 through the check valve 10. On the other hand, the adsorption tower 8
The conduit 15 at the lower end is connected to the nitrogen gas exhaust pipe 16 via the four-way rotary valve 6 and communicates with the outside of the system at atmospheric pressure via the check valve 11. Therefore, the nitrogen gas adsorbed by the nitrogen adsorbent 9 in the adsorption tower 8 is desorbed under reduced pressure and discharged to the outside of the system. When a certain amount of air is supplied to the adsorption tower 7 and reaches a predetermined pressurization state, the rotor of the four-way rotary valve 6 that is interlocked with the rotation of the air pump 1 is rotated 90 ^° , and the outlet pipe 13 of the air pump 1 is adsorbed. In the conduit 15 of the tower 8, the adsorption tower 7
Conduits 14 are connected to nitrogen gas exhaust pipes 16, respectively,
The switching of the flow path between the pressure adsorption step and the reduced pressure desorption regeneration step is completed. In this way, by using the drive source of the air pump to simultaneously rotate the four-way rotary valve,
The flow path of the adsorption tower can be switched to adsorption-regeneration-adsorption according to the amount of air supplied to the adsorption tower. It became possible to do.

[0009]

According to the present invention, by adopting the above configuration, the four-way rotary valve for switching the flow path of the adsorption tower can be rotated in association with the drive source of the pump for pressurizing the gas to be treated. The adsorption step can be completed according to the amount of the gas to be treated supplied to the adsorption tower. Therefore, even if the supply amount of the gas to be treated decreases due to voltage fluctuations or frequency changes, the rotation speed of the four-way rotary valve decreases correspondingly, and the cycle time becomes longer. Automatically increase pressure until pressure is reached. as a result,
The non-adsorbed component gas, which is the product gas, can be recovered without lowering the concentration. Further, it is possible to omit a motor for driving the four-way port rotary valve, a sequencer for controlling the four-way rotary valve, a timer or a supplementary facility such as a microcomputer, thereby reducing the device cost.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an air separation pressure swing adsorption device that is an embodiment of the present invention.

FIG. 2 is a sectional view of a four-way rotary valve used in FIG.

FIG. 3 is an enlarged view showing a relationship between a drive motor of the air pump of FIG. 1 and a four-way opening rotary valve.

FIG. 4 is an explanatory view of a conventional pressure swing adsorption device for air separation.

Claims (1)

[Claims] 1. One end of each of the two adsorption towers is connected to a four-way rotary valve, and the other end is connected to a product gas exhaust pipe for non-adsorbed components via respective check valves, and the rotary valve is also provided. Is connected to a treated gas introduction pipe equipped with a pressure pump and an adsorption component desorption gas exhaust pipe, and the two adsorption towers are separated into a pressure adsorption process and a decompression desorption regeneration process by driving the rotary valve. In the pressure swing adsorption type gas separation device which is alternately switched between, the drive motor of the pressurizing pump of the gas to be treated introduction pipe is connected to the four-way rotary valve through a speed reducing means. apparatus.