JP2948367B2 - Gas separation equipment - Google Patents

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 separation apparatus, and is suitable for, for example, 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 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 passed through the check valve 10.
Collect. On the other hand, the adsorption tower 8 or 7 in the regeneration step
Nitrogen adsorbed in the adsorption tower, which is connected to the exhaust system 16 at atmospheric pressure via the five-way solenoid valve 6 ', is decompressed and desorbed and discharged to the exhaust system 16. The 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 the motor 2 is provided with a cooling fan 3.

[0003]

In the above-mentioned gas separation apparatus of the pressure adsorption / decompression / desorption regeneration system, a five-way solenoid valve is provided on the side of the adsorption tower on which the gas to be treated is supplied as means for switching the gas flow. The five-way solenoid valve is controlled by a timer, a microcomputer, or the like, and is switched at regular intervals. In this method, if the voltage changes during operation, the capacity of the air pump fluctuates regardless of whether the motor is an AC motor or a DC motor. For example, when the voltage decreases, the outlet pressure of the air pump decreases. And the pressure inside the adsorption tower cannot be raised to a predetermined pressure within a certain period of time, and the oxygen concentration of the product gas decreases. Therefore, the present invention solves the above-mentioned problems and replaces the switching between adsorption and regeneration with a switching method at regular time intervals using a sequencer, a timer, a microcomputer, or the like. 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 of a non-adsorbed component through a respective check valve. Connected, and the rotary valve is connected to a gas introduction pipe to be treated equipped with a pressure pump and a gas exhaust pipe for desorbing adsorbed components, and by driving the rotary valve,
In a pressure swing adsorption type gas separation apparatus in which two adsorption towers are alternately switched between a pressure adsorption step and a vacuum desorption / regeneration step, a driving motor of a pressure pump of the gas introduction pipe to be treated is controlled by a deceleration means. A gas separation device connected to the four-way rotary valve. In addition, as the speed reduction means, for example, it is possible to perform the reduction by engaging a drive gear provided on the shaft of the motor with a reduction gear provided on the shaft of the rotary valve. Is set by selecting the number of teeth of both.

[0005]

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

In the gas separation device of the present invention, since the four-way rotary valve is connected via 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 If the rotation angle of the rotary valve can be made proportional and the reduction ratio of the gears is set appropriately, the switching of the four-way 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 the voltage or the like, the four-way rotary valve can be switched in accordance with the amount of air supplied. And a reduction in the concentration of the recovered oxygen can be avoided. As described above, the case of recovering oxygen from air has been described as an example. However, the present invention can be applied to gas separation other than air, and the same effects as above can be obtained.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. 1 is an overall view of a pressure swing adsorption type gas separator, FIG. 2 is a sectional view of a four-way rotary valve, and FIG. 3 is an enlarged view showing a relationship between a motor for a pressurizing pump and a four-way rotary valve. is there. The air to be treated is supplied to the suction pipe 12.
It is taken into the air pump 1, pressurized and sent to 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 has a rotor having a structure in which two adjacent openings communicate with each other. As shown in FIG. 3, a reduction gear 5 is mounted on the shaft of the rotor, and a drive gear 4 is mounted on the shaft of the motor 2 for the air pump. Since the driving force of the pump motor 2 is reduced and transmitted to the four-way rotary valve 6, the air pump 1 and the four-way rotary valve 6 rotate in conjunction with each other. That is, while the air pump 1 is operating, the four-way rotary valve 6 is also constantly rotating. By appropriately selecting the number of teeth of the drive gear 4 and the reduction gear 5 and determining the reduction ratio,
The switching timing of the four-way rotary valve 6 can be determined according to the supply air amount.

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

[0009]

According to the present invention, by employing the above structure, the four-way rotary valve for switching the flow path of the adsorption tower can be rotated in conjunction with the drive source of the pump for pressurizing the gas to be treated. In addition, the adsorption step can be terminated according to the supply amount of the gas to be treated to the adsorption tower. Therefore, even if the supply amount of the gas to be treated is reduced due to a voltage fluctuation or a frequency change, the rotation speed of the four-way rotary valve is correspondingly reduced, and the cycle time becomes longer. Increase pressure automatically until pressure is reached. as a result,
The non-adsorbed component gas, which is a product gas, can be recovered without lowering the concentration. Further, a motor for driving the four-way rotary valve, and ancillary equipment such as a sequencer, a timer, and a microcomputer for controlling the motor can be omitted, and the apparatus cost can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a pressure swing adsorption device for air separation according to one 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 rotary valve.

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

Claims (1)

(57) [Claims] 1. 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 of a non-adsorbed component through a respective check valve, and said rotary valve Is connected to a gas introduction pipe to be treated equipped with a pressure pump and a gas exhaust pipe for desorbing the adsorbed component, and by driving the rotary valve, the two adsorption towers are connected to the pressure adsorption step and the decompression desorption regeneration step. In a pressure swing adsorption type gas separation device which alternately switches between the four-port rotary valve via a deceleration means, a driving motor for a pressure pump of the gas introduction pipe to be treated is connected. apparatus.