Rotary valve multi-tower pressure swing adsorption device

Abstract

The utility model provides a rotary valve multi-tower pressure swing adsorption device which comprises a feeding flow controller, a rotary valve lower valve group, an adsorption tower group, a rotary valve upper valve group, a motor, a speed reducer, a product gas back pressure controller, a purge gas flowmeter and a device frame, the feeding flow controller, the purge gas flowmeter and the bottoms of the adsorption towers are connected with the lower valve bank through pipelines, the product gas back pressure controller and the tops of the adsorption towers are connected with the upper valve bank through pipelines, and a plurality of channels are formed in the upper valve bank and the lower valve bank of the rotary valve. And the motor and the speed reducer drive the upper valve group and the lower valve group to synchronously and continuously rotate so as to switch and control the technical processes of adsorption, desorption, pressure equalization and the like of each tower. According to the device provided by the utility model, the rotary valve is adopted to simplify the traditional pressure swing adsorption control logic, the highly integrated process route design is combined, the multi-stage pressure equalization is realized by using a small number of towers, the occupied area of the whole device is reduced, and the whole device is simple to operate and can be designed and constructed in a skid-mounted manner.

Description

Technical Field

[0001] This utility model belongs to the field of pressure swing adsorption gas purification and upgrading technology, specifically relating to a rotary valve multi-tower pressure swing adsorption device. Background Technology

[0002] Currently, the main methods for gas separation and purification both domestically and internationally include cryogenic separation, membrane separation, chemical absorption separation, and pressure swing adsorption (PSA) separation, among which PSA has the widest application. Statistics show that over 90% of coal gasification hydrogen production units in the petrochemical industry utilize PSA purification technology.

[0003] Most existing PSA technologies employ multi-tower setups. Individual towers operate in an intermittent batch processing mode, separating a batch of gas through processes such as feeding, adsorption, desorption, and venting. With multiple towers, programmable valves control the adsorption, pressure equalization, and desorption states of each tower, creating a macroscopically continuous gas separation operation. The entire system has a large number of valves and complex piping connections. During the pressure swing adsorption process, frequent and periodic valve switching is required, making the control program quite complex. Furthermore, the adsorption units in pressure swing adsorption systems are mostly installed side-by-side, resulting in a large overall footprint.

[0004] Replacing traditional parallel-type programmable valves with rotary valves significantly simplifies control logic and reduces the number of adsorption devices. In pressure swing adsorption (PSA) technology, the number of equalization cycles affects product yield; increasing the number of equalization cycles improves yield, but also necessitates a corresponding increase in tower equipment. Utility model patent CN 215233147 U discloses an adsorption device that uses a gas distribution valve to control the PSA unit. This gas distribution valve employs a circumferential periodic control method, increasing the device's compactness. Patent CN112892153 A invented a PSA process based on a multi-channel rotary valve, achieving high integration and a smaller footprint. However, both patents CN 215233147 U and CN 112892153 A require six tower devices for two equalization cycles and nine tower devices for three equalization cycles, indicating an excessive number of tower devices. Further process optimization could reduce the number of tower devices, thereby decreasing the footprint and lowering overall investment. Utility Model Content

[0005] This invention addresses the shortcomings of existing pressure swing adsorption (PSA) technologies, such as a large number of valves, complex control procedures, numerous tower devices, and large floor space requirements, by proposing a rotary valve multi-tower PSA device.

[0006] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0007] A rotary valve multi-tower pressure swing adsorption device includes a feed flow controller, a lower rotary valve assembly, an adsorption tower assembly, an upper rotary valve assembly, a motor and reducer, a product gas back pressure controller, a release gas flow meter, and a device frame. The feed flow controller, the release gas flow meter, and the bottom of each adsorption tower in the adsorption tower assembly are connected to the lower rotary valve assembly via pipelines. The product gas back pressure controller and the top of each adsorption tower in the adsorption tower assembly are connected to the upper rotary valve assembly via pipelines. Both the upper and lower rotary valve assemblies have several channels inside. The adsorption, desorption, and pressure equalization operations of each adsorption tower in the adsorption tower assembly are switched by the motor synchronously driving the upper and lower rotary valve assemblies to rotate continuously.

[0008] Preferably, the upper valve group and the lower valve group of the rotary valve described above are each two separate rotary valve groups. The upper valve group includes an upper valve stator and an upper valve rotor, and the lower valve group includes a lower valve stator and a lower valve rotor.

[0009] Preferably, the upper valve stator is divided into upper and lower parts on the upper end face of the upper valve rotor. The lower part of the upper valve stator has channels on its side that are opened according to the number of adsorption towers, and each channel is connected to the top of the adsorption tower through pipelines. The upper part of the upper valve stator is a pressure chamber. A product gas channel is opened on the upper end face of the upper valve rotor. The product gas coming out of the upper valve rotor directly enters the pressure chamber. The top of the pressure chamber has an opening that is connected to the product gas back pressure controller through a pipeline. The upper valve rotor has a pressure equalization channel and a product gas channel inside.

[0010] Preferably, the upper valve rotor described above includes at least one pressure equalization channel, wherein the three pressure equalization methods can be used for seven-tower and eight-tower equipment.

[0011] Preferably, the lower valve stator described above is divided into upper and lower parts on the lower end face of the lower valve rotor. The lower part of the lower valve stator is a pressure chamber with an opening at the bottom, which is connected to the feed flow controller via a pipe. The feed gas enters the pressure chamber below the lower valve stator directly after the flow control is applied. The lower end face of the lower valve rotor has a feed gas channel, through which the feed gas in the stator pressure chamber enters the rotor directly. The upper side of the lower valve stator is provided with channels opened according to the number of adsorption towers, which are connected to the bottom of each adsorption tower via pipes. The upper side of the lower valve stator also has another channel, which is connected to the purge gas flow meter via a pipe. The lower valve rotor is provided with a feed channel and a purge gas channel inside.

[0012] Preferably, the above features include an upper valve group and a lower valve group of the rotary valve connected by a shaft, which rotate synchronously and continuously under the drive of a motor and a reducer, wherein the speed of the motor is adjustable.

[0013] Preferably, the adsorption tower group described above includes several adsorption towers, each of the same size, and each adsorption tower is filled with a special adsorbent, which includes one or more of alumina, molecular sieve, silica gel, and activated carbon.

[0014] The aforementioned pressure swing adsorption includes processes such as adsorption, desorption, and pressure equalization. The process of each adsorption tower is directly related to the operating state of the rotary valve. The purity and yield of the product gas in the pressure swing adsorption unit are mainly controlled by changing the rotary valve speed and the product back pressure controller.

[0015] The gas separation and purification process of a rotary valve multi-tower pressure swing adsorption unit:

[0016] (1) The raw gas is metered and controlled by the feed flow controller and fed from the raw gas inlet at the bottom of the lower valve stator of the rotary valve. Then it enters the bottom of each adsorption tower through the channel of the lower valve rotor and is adsorbed under a certain pressure.

[0017] (2) The product gas generated by the adsorption tower comes out from the top of the tower and enters the upper valve group of the rotary valve. After being controlled by the internal channel of the upper valve group rotor, it is collected into the upper valve stator pressure chamber. Finally, it enters the product gas back pressure controller from the top of the stator. After being controlled by the back pressure and metered by the flow rate, it exits the device.

[0018] (3) After the adsorption step in the adsorption tower is completed, pressure equalization is required. The pressure equalization process is completed through the pressure equalization channel of the upper valve.

[0019] (4) After pressure equalization is completed, the remaining low-pressure gas in the tower is desorbed and discharged. After flowing out from the bottom of the tower, it is controlled by the lower valve group and then discharged from the lower valve stator exhaust port.

[0020] (5) The control steps involved in the operation process (1) to (4) are all controlled by rotating the rotary valve.

[0021] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0022] The rotary valve in the multi-tower pressure swing adsorption (PSA) device provided by this invention has significant advantages over the programmable valves used in traditional PSA. The synchronous rotation of the upper and lower valve groups enables rapid switching between towers, simplifying the control logic and process flow of traditional PSA. The rapid and continuous switching of the rotary valve can reduce the overall amount of adsorbent used, thereby reducing the size of the adsorption equipment. Combined with a highly integrated process route design, the number of towers used under three equalization conditions can be reduced to seven, reducing the overall footprint and total investment of the device. The entire device is simple to operate and can be designed and constructed in a skid-mounted manner. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of the rotary valve multi-tower pressure swing adsorption device of this utility model;

[0025] Figure 2 This is a top view of the rotary valve multi-tower pressure swing adsorption device of this utility model;

[0026] Figure 3 This is a schematic diagram of the upper valve rotor in this utility model;

[0027] Figure 4 This is a schematic diagram of the structure of the lower valve rotor in this utility model.

[0028] In the diagram: 1-Lower valve assembly of rotary valve; 2-Product gas flow controller; 3-Adsorption tower assembly; 4-Motor; 5-Upper valve assembly of rotary valve; 6-Equipment frame; 7-Feed flow controller; 8-Releasing gas flow meter; 9-Equalizing channel; 10-Product gas channel of upper valve rotor; 11-Connection channel between upper valve rotor and adsorption tower; 12-Raw gas inlet; 13-Connection channel between lower valve rotor and adsorption tower; 14-Releasing gas channel of lower valve rotor; 15-Releasing gas groove of lower valve rotor. Detailed Implementation

[0029] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding of this utility model, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0030] Reference Figures 1-2 A rotary valve multi-tower pressure swing adsorption device includes a feed flow controller 7, a lower rotary valve group 1, an adsorption tower group 3, an upper rotary valve group 5, a product gas back pressure controller 2, and a release gas flow meter 8. The lower rotary valve group 1 and the upper rotary valve group 5 are connected by a shaft and are driven to rotate synchronously by a motor 4 and a reducer. The adsorption tower group 3 is composed of multiple adsorption towers of the same size.

[0031] After being metered and controlled by the feed flow controller 7, the raw gas is fed into the lower valve group 1 of the rotary valve, and then enters the adsorption tower in the adsorption tower group 3 for adsorption and separation. The product gas generated by the adsorption tower group 3 comes out from the top of the tower, enters the upper valve group 5 of the rotary valve, and flows out from the upper valve stator after being controlled by the internal channel of the upper valve group 5. It is also metered and controlled by the product gas back pressure controller 2.

[0032] After the adsorption step in the adsorption tower is completed, pressure equalization is required. The pressure equalization process is completed through the pressure equalization channel of the upper valve group 5 of the rotary valve. After pressure equalization is completed, the remaining low-pressure gas in the tower needs to be desorbed and discharged. After flowing out from the bottom of the tower, it is controlled by the lower valve group and then discharged from the lower valve stator in the lower valve group 1 of the rotary valve, and is measured by the venting gas flow meter 8.

[0033] The state of each adsorption tower in adsorption tower group 3 is controlled by switching the internal channels between the lower valve group 1 and the upper valve group 5 of the rotary valve. The switching of the internal channels between the upper and lower valve groups of the rotary valve is mainly achieved by the rotation of the rotor of the rotary valve group driven by the motor 4 and the reducer.

[0034] like Figure 3 As shown, the upper valve rotor is provided with a pressure equalization channel 9, an upper valve rotor product gas channel 10, and an upper valve rotor and adsorption tower connection channel 11, wherein the upper valve rotor product gas channel 10 and the upper valve rotor and adsorption tower connection channel 11 are connected by an internal channel.

[0035] like Figure 4 As shown, the lower valve rotor is provided with a lower valve rotor raw material gas channel 12, a lower valve rotor and adsorption tower connection channel 13, a lower valve rotor vent gas channel 14, and a lower valve rotor vent gas groove 15; wherein the lower valve rotor raw material gas channel 12 and the lower valve rotor and adsorption tower connection channel 13 are connected through an internal channel, and the lower valve rotor vent gas groove 15 is an annular groove and is interconnected with the lower valve rotor vent gas channel 14.

[0036] The specific working principle is as follows: After the raw material gas is metered and controlled by the feed flow controller 7, it passes through the raw material gas channel 12 of the lower valve rotor, the connection channel 13 between the lower valve rotor and the adsorption tower, and then enters the adsorption tower in the adsorption tower group 3 for adsorption and separation. The product gas generated by the adsorption tower group 3 exits from the top of the tower and passes through the connection channel 11 between the upper valve rotor and the adsorption tower, the product gas channel 10 of the upper valve rotor, and then flows out of the upper valve group from the product gas outlet of the upper valve stator in the rotary valve upper valve group 5. The product gas is metered and controlled by the product gas back pressure controller 2 to obtain the product gas.

[0037] After the adsorption steps of each adsorption tower are completed, the pressure is equalized / depressurized through the equalization channel 9. After the equalization is completed, the remaining low-pressure gas in the tower needs to be desorbed and discharged. The purge gas discharged from the bottom of the tower passes through the lower valve rotor purge gas channel 14 and the lower valve rotor purge gas groove 15 in sequence, and then flows out from the stator purge gas outlet in the lower valve group 1 of the rotary valve. The tail gas flow rate is measured by the purge gas flow meter 8.

[0038] The embodiments of this utility model have been described in detail above with reference to the accompanying drawings, but this utility model is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of this utility model, and these variations still fall within the protection scope of this utility model.

Claims

1. A rotary valve multi-tower pressure swing adsorption device, characterized in that, The device includes a feed flow controller, a lower rotary valve assembly, an adsorption tower assembly, an upper rotary valve assembly, a motor and reducer, a product gas back pressure controller, a release gas flow meter, and a frame. The feed flow controller, the release gas flow meter, and the bottom of each adsorption tower in the adsorption tower assembly are connected to the lower rotary valve assembly via pipelines. The product gas back pressure controller and the top of each adsorption tower in the adsorption tower assembly are connected to the upper rotary valve assembly via pipelines. Both the upper and lower rotary valve assemblies have several channels inside. The motor synchronously drives the upper and lower rotary valve assemblies to rotate continuously, thereby switching and controlling the adsorption, desorption, and pressure equalization operations of each adsorption tower in the adsorption tower assembly.

2. The rotary valve multi-tower pressure swing adsorption device according to claim 1, characterized in that, The upper valve group and the lower valve group of the rotary valve are each two separate rotary valve groups. The upper valve group includes an upper valve stator and an upper valve rotor, and the lower valve group includes a lower valve stator and a lower valve rotor.

3. The rotary valve multi-tower pressure swing adsorption device according to claim 2, characterized in that, The upper valve stator is divided into upper and lower parts on the upper end face of the upper valve rotor. The lower part of the upper valve stator has channels on its side that are opened according to the number of adsorption towers, and each channel is connected to the top of the adsorption tower through pipelines. The upper part of the upper valve stator is a pressure chamber. A product gas channel is opened on the upper end face of the upper valve rotor. The product gas coming out of the upper valve rotor directly enters the pressure chamber. The top of the pressure chamber has an opening that is connected to the product gas back pressure controller through a pipeline. The upper valve rotor has a pressure equalization channel and a product gas channel inside.

4. The rotary valve multi-tower pressure swing adsorption device according to claim 3, characterized in that, The upper valve rotor includes at least one pressure equalization channel, wherein three pressure equalizations can be used for seven-tower and eight-tower equipment.

5. The rotary valve multi-tower pressure swing adsorption device according to claim 2, characterized in that, The lower valve stator is divided into upper and lower parts on the lower end face of the lower valve rotor. The lower part of the lower valve stator is a pressure chamber with an opening at the bottom, which is connected to the feed flow controller through a pipe. The feed gas enters the pressure chamber below the lower valve stator directly after the flow control is applied. The lower end face of the lower valve rotor has a feed gas channel, through which the feed gas in the stator pressure chamber enters the rotor directly. The upper side of the lower valve stator is provided with channels opened according to the number of adsorption towers, which are connected to the bottom of each adsorption tower through pipes. The upper side of the lower valve stator also has another channel, which is connected to the purge gas flow meter through a pipe. The lower valve rotor has a feed channel and a purge gas channel inside.

6. A rotary valve multi-tower pressure swing adsorption device according to any one of claims 1-5, characterized in that, The upper and lower valve groups of the rotary valve are connected by a shaft and rotate synchronously and continuously under the drive of a motor and a reducer. The speed of the motor is adjustable.

7. A rotary valve multi-tower pressure swing adsorption device according to claim 6, characterized in that, The adsorption tower group includes several adsorption towers, each of the same size, and each adsorption tower is filled with a special adsorbent, which includes one or more of alumina, molecular sieve, silica gel, and activated carbon.

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