Integrated valve block for pressure swing adsorption air separation device

Abstract

The utility model discloses an integrated valve block for a pressure swing adsorption air separation device, which comprises a valve group a and a valve group b, an air inlet pipe is arranged at one end of the valve group a, a connecting pipe group a is arranged at the other end of the valve group a, a flowing pipe group a is arranged in the valve group a, and the air inlet pipe and the connecting pipe group a are both communicated with the flowing pipe group a; an air guide pipe is arranged at one end of the valve group b, a connecting pipe group b is arranged at the other end of the valve group b, a flowing pipe group b is arranged in the valve group b, and the air guide pipe and the connecting pipe group b are both communicated with the flowing pipe group b. A connecting pipe set a and a connecting pipe set b are connected with an adsorber set, meanwhile, an air inlet pipe is communicated with the connecting pipe set a and a flowing pipe set a, an air guide pipe is communicated with the connecting pipe set b and a flowing pipe set b, raw material air is guided in through the air inlet pipe, and then product air is output through the adsorption effect of filler in the adsorber set by controlling opening and closing of a corresponding pneumatic valve. Therefore, the number of threaded connectors is reduced, the welding workload is reduced, the assembly process is simplified, and the efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of normal temperature air separation pressure swing adsorption, in particular to an integrated valve block for a pressure swing adsorption air separation device. Background Art

[0002] The assembly diagram of the upper and lower valve groups of the traditional production process of the pressure swing adsorption air separation equipment (oxygen and nitrogen production) is as follows: Figure 1 and Figure 2 As shown, the lower valve group is mainly composed of an air intake regulating valve 111, a left air intake valve 112, a right air intake valve 113, a left vent valve 114, a right vent valve 115, a lower valve group equalizing valve 116, a vent silencer 117 and pipelines; the upper valve group is mainly composed of an upper valve group equalizing valve 118, a left gas production valve 119, a right gas production valve 120, a gas production regulating valve 121, a purge pipe 122 and pipelines. The components numbered 112 to 120 are opened and closed according to a certain timing logic through software control.

[0003] The logic of controlling the fluid flow direction of components No. 112 to 120 is as follows:

[0004] When the left adsorber is working, numbers 112, 115, and 119 are open, numbers 113, 114, 116, 118, and 120 are closed, and the raw air enters the left adsorber through the left pipeline of the lower valve group, and the product gas is output through the left pipeline of the upper valve group after the adsorption of the filler in the adsorber. At the same time, the waste gas adsorbed by the filler in the right adsorber flows to number 117 through number 115 for venting. When the left adsorber adsorbs and the right adsorber vents, numbers 112, 113, 114, 115, 119, and 120 are closed, numbers 116 and 118 are opened, and the left adsorber is pressure-equalized with the right adsorber. After the pressure equalization is completed, the right adsorber performs adsorption work. At this time, numbers 113, 114, and 120 are opened, and numbers 112, 115, 116, 118, and 119 are closed. The raw air enters the right adsorber through the right pipeline of the lower valve group, and the product gas is output through the right pipeline of the upper valve group through the adsorption effect of the filler in the adsorber. At the same time, the waste gas adsorbed by the filler in the left adsorber flows to number 117 through number 114 for venting. When the adsorption of the right adsorber is completed, the venting of the left adsorber is completed. At this time, numbers 112, 113, 114, 115, 119, and 120 are closed, and numbers 116 and 118 are opened. The right adsorber performs pressure equalization with the left adsorber. After the pressure equalization is completed, the left adsorber performs adsorption work... Such a cycle realizes the continuous operation of the pressure swing adsorption air separation equipment and outputs oxygen or nitrogen.

[0005] However, the valve group assembled by the traditional production process has large external dimensions, many threaded connection interfaces (the above-mentioned valves and pipelines are all threaded connections), a large welding workload, and a complicated assembly process, which reduces production efficiency; and because of the large number of threaded connection interfaces, it also increases the risk of pipeline leakage and the difficulty of maintenance. Utility Model Content

[0006] The utility model aims to overcome the disadvantages of the prior art and provide an integrated valve block for a pressure swing adsorption air separation device.

[0007] The purpose of the utility model is achieved through the following technical solutions: an integrated valve block for a pressure swing adsorption air separation device, comprising a valve group a and a valve group b, wherein an air inlet pipe is arranged at one end of the valve group a, and a connecting pipe group a is arranged at the other end of the valve group a, and the connecting pipe group a is connected with the air inlet of the adsorber group, a flow pipe group a is arranged in the valve group a, and a corresponding pneumatic valve is arranged at the end of the flow pipe group a, and the air inlet pipe and the connecting pipe group a are both connected with the flow pipe group a; an air guide pipe is arranged at one end of the valve group b, and a connecting pipe group b is arranged at the other end of the valve group b, and the connecting pipe group b is connected with the air outlet of the adsorber group, a flow pipe group b is arranged in the valve group b, and a corresponding pneumatic valve is arranged at the end of the flow pipe group b, and the air guide pipe and the connecting pipe group b are both connected with the flow pipe group b, and the other end of the air guide pipe is connected with a buffer tank.

[0008] Preferably, the adsorber group includes adsorber a and adsorber b, the connecting pipe group a includes connecting pipe a and connecting pipe b, both connecting pipe a and connecting pipe b are connected to the flow pipe group a, and connecting pipe a is connected to the air inlet of adsorber a, and connecting pipe b is connected to the air inlet of adsorber b.

[0009] Preferably, the flow pipe group a includes pipeline a, pipeline b, pipeline c, pipeline d and pipeline z, pipeline a, pipeline c and pipeline z are horizontally opened in valve group a, pipeline b and pipeline d are vertically opened in valve group a, and pipeline a, pipeline b, pipeline c, pipeline d and pipeline z are interconnected, the air outlet of the air inlet pipe is connected to the middle section of pipeline a, the connecting pipe a is connected to pipeline b, and the connecting pipe b is connected to pipeline d.

[0010] Preferably, a left air intake pneumatic valve and a right air intake pneumatic valve are respectively provided at both ends of pipeline a, a pressure equalizing pneumatic valve is provided at both ends of pipeline z, and a left air vent pneumatic valve and a right air vent pneumatic valve are respectively provided at both ends of pipeline c.

[0011] Preferably, it also includes a venting silencer, which is connected to the pipeline c through the pipeline e.

[0012] Preferably, an intake regulating valve is provided on the intake pipe.

[0013] Preferably, the connecting pipe group b includes a connecting pipe c and a connecting pipe d, both the connecting pipe c and the connecting pipe d are connected to the flow pipe group b, and the connecting pipe c is connected to the gas outlet of the adsorber a, and the connecting pipe d is connected to the gas outlet of the adsorber b.

[0014] Preferably, the flow pipe group B includes pipeline f29, pipeline g30, pipeline h32 and pipeline k33, pipeline f29 and pipeline g30 are vertically opened in the valve group b14, pipeline h32 and pipeline k33 are horizontally opened in the valve group b14, and pipeline f29, pipeline g30, pipeline h32 and pipeline k33 are interconnected, the air inlet of the air guide pipe 19 is connected to the middle section of the pipeline k33, the connecting pipe c21 is connected to the pipeline f29, and the connecting pipe d20 is connected to the pipeline g30.

[0015] Preferably, a connecting pipe is further provided in the valve group b, the two ends of the connecting pipe are respectively connected with the pipeline f and the pipeline g, and the connecting pipe is located above the pipeline h.

[0016] Preferably, a pressure-equalizing pneumatic valve b is provided at one end of the pipeline h, a left gas-producing pneumatic valve and a right gas-producing pneumatic valve are provided at both ends of the pipeline k, and a gas-producing regulating valve is provided on the air guide pipe.

[0017] The utility model has the following advantages: the utility model sets valve group a and valve group b, and connects the adsorber group through connecting pipe group a and connecting pipe group b, and at the same time, the air inlet pipe is connected with connecting pipe group a and flow pipe group a, and the air guide pipe is connected with connecting pipe group b and flow pipe group b. First, the air inlet pipe introduces raw air, and then controls the opening and closing of the corresponding pneumatic valve to output product gas through the adsorption effect of the filler in the adsorber group, thereby reducing the number of threaded interfaces, thereby reducing the welding workload, simplifying the assembly process, and improving efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of the valve group assembly under the traditional production process;

[0019] Figure 2 This is a schematic diagram of the structure of the valve group assembly in the traditional production process;

[0020] Figure 3 It is a schematic diagram of the structure of the valve group b in the integrated valve block;

[0021] Figure 4 It is a schematic diagram of the structure of the valve group a in the integrated valve block;

[0022] Figure 5 It is a structural schematic diagram of the cross-section of the assembly of valve group b in the integrated valve block;

[0023] Figure 6 It is a structural schematic diagram of the cross-section of the assembly of valve group a in the integrated valve block;

[0024] In the figure, 1-intake regulating valve, 2-left intake pneumatic valve, 3-right intake pneumatic valve, 4-left vent pneumatic valve, 5-right vent pneumatic valve, 6-pressure equalizing pneumatic valve, 7-pressure equalizing pneumatic valve b, 8-left gas production pneumatic valve, 9-right gas production pneumatic valve, 10-venting silencer, 11-gas production regulating valve, 13-valve group a, 14-valve group b, 15-pressure detection joint, 16-intake pipe, 17-connecting pipe a, 18-connecting pipe b, 19-air guide pipe, 20-connecting pipe d, 21-connecting pipe c, 22-product air pressure detection joint, 23-pipeline a, 24-pipeline b, 25-pipeline c, 26-pipeline e, 27-pipeline d, 28-pipeline z, 29-pipeline f, 30-pipeline g, 31-connecting pipe, 32-pipeline h, 33-pipeline k. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention for which protection is sought, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features thereof may be combined with each other.

[0028] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0029] In the description of the present utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the utility model product is usually placed when in use, or the positions or positional relationships commonly understood by those skilled in the art, which are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0030] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] In this embodiment, if Figure 3 and Figure 4As shown, an integrated valve block for a pressure swing adsorption air separation device includes a valve group a13 and a valve group b14, wherein an air inlet pipe 16 is provided at one end of the valve group a13, and preferably, an air inlet regulating valve 1 is provided on the air inlet pipe 16. A connecting pipe group a is provided at the other end of the valve group a13, and the connecting pipe group a is communicated with the air inlet of the adsorber group, a flow pipe group a is provided in the valve group a13, and a corresponding pneumatic valve is provided at the end of the flow pipe group a, and the air inlet pipe 16 and the connecting pipe group a are both communicated with the flow pipe group a; an air guide pipe 19 is provided at one end of the valve group b14, and a connecting pipe group b is provided at the other end of the valve group b14, and the connecting pipe group b is communicated with the air outlet of the adsorber group, a flow pipe group b is provided in the valve group b14, and a corresponding pneumatic valve is provided at the end of the flow pipe group b, and the air guide pipe 19 and the connecting pipe group b are both communicated with the flow pipe group b, and the other end of the air guide pipe 19 is communicated with the buffer tank. By setting valve group a13 and valve group b14, and connecting the adsorber group through connecting pipe group a and connecting pipe group b, while the air inlet pipe 16 and connecting pipe group a are connected to the flow pipe group a, and the air guide pipe 19 and connecting pipe group b are connected to the flow pipe group b, the air inlet pipe 16 first introduces the raw air, and then controls the opening and closing of the corresponding pneumatic valve, and outputs the product gas through the adsorption effect of the filler in the adsorber group, thereby reducing the number of threaded interfaces, thereby reducing the welding workload and simplifying the assembly process, and improving efficiency. In this embodiment, all the pneumatic valves and adsorbers used are existing products, which can be purchased from the market according to actual conditions, and will not be described here.

[0032] Further, the adsorber group includes adsorber a and adsorber b, the connecting pipe group a includes connecting pipe a17 and connecting pipe b18, the connecting pipe a17 and the connecting pipe b18 are both connected to the flow pipe group a, and the connecting pipe a17 is connected to the air inlet of the adsorber a, and the connecting pipe b18 is connected to the air inlet of the adsorber b. Further, as Figure 6As shown, the flow pipe group a includes pipeline a23, pipeline b24, pipeline c25, pipeline d27 and pipeline z28, pipeline a23, pipeline c25 and pipeline z28 are horizontally opened in the valve group a13, pipeline b24 and pipeline d27 are vertically opened in the valve group a13, and pipeline a23, pipeline b24, pipeline c25, pipeline d27 and pipeline z28 are interconnected, the air outlet of the air inlet pipe 16 is connected with the middle section of pipeline a23, the connecting pipe a17 is connected with pipeline b24, and the connecting pipe b18 is connected with pipeline d27. Specifically, the interconnection of pipeline a23, pipeline b24, pipeline c25, pipeline d27 and pipeline z28 means that pipeline a23, pipeline c25 and pipeline z28 are connected through pipeline b24 and pipeline d27, or pipeline b24 and pipeline d27 are connected through pipeline a23, pipeline c25 and pipeline z28, and their connections are vertically connected. In this embodiment, the two ends of pipeline a23 are respectively provided with a left air intake pneumatic valve 2 and a right air intake pneumatic valve 3, the two ends of pipeline z28 are respectively provided with a pressure equalizing pneumatic valve 6, and the two ends of pipeline c25 are respectively provided with a left vent pneumatic valve 4 and a right vent pneumatic valve 5. Furthermore, it also includes a venting silencer 10, which is connected to pipeline c25 through pipeline e26.

[0033] In this embodiment, the connecting pipe group b includes a connecting pipe c21 and a connecting pipe d20, both of which are connected to the flow pipe group b, and the connecting pipe c21 is connected to the gas outlet of the adsorber a, and the connecting pipe d20 is connected to the gas outlet of the adsorber b. Figure 5 As shown, the flow pipe group B includes pipeline f29, pipeline g30, pipeline h32 and pipeline k33, pipeline f29 and pipeline g30 are vertically opened in valve group b14, pipeline h32 and pipeline k33 are horizontally opened in valve group b14, and pipeline f29, pipeline g30, pipeline h32 and pipeline k33 are interconnected, the air inlet of the air guide pipe 19 is connected to the middle section of pipeline k33, the connecting pipe c21 is connected to pipeline f29, and the connecting pipe d20 is connected to pipeline g30. Preferably, a pressure equalizing pneumatic valve b7 is provided at one end of pipeline h32, a left gas production pneumatic valve 8 and a right gas production pneumatic valve 9 are respectively provided at both ends of pipeline k33, and a gas production regulating valve 11 is provided on the air guide pipe 19. Furthermore, a connecting pipe 31 is provided in the valve group b14, and two ends of the connecting pipe 31 are respectively connected to the pipeline f29 and the pipeline g30, and the connecting pipe 31 is located above the pipeline h32.

[0034] In this embodiment, the valve group b14 is provided with a plurality of pressure detection interfaces 15 and a product gas pressure detection connector 22, and the product gas pressure detection connector 22 is used to detect the product gas pressure in the gas guide pipe 19. Preferably, there are two pressure detection interfaces 15, which are used to detect the pressure of adsorber a and adsorber b respectively.

[0035] The working process of the utility model is as follows: when the adsorber a is working, the left air intake pneumatic valve 2, the right air release pneumatic valve 5 and the left gas production pneumatic valve 8 are opened, the right air intake pneumatic valve 3, the left air release pneumatic valve 4, the pressure equalizing pneumatic valve 6, the pressure equalizing pneumatic valve b7 and the right gas production pneumatic valve 9 are closed, and the raw material air enters the adsorber a through the air intake pipe 16, the internal pipeline of the valve group a13 and the connecting pipe a17, and after the adsorption of the filler in the adsorber a, it enters the internal pipeline of the valve group b14 through the connecting pipe c21, and finally enters the internal pipeline of the valve group b14 through the air guide pipe 1 9 outputs product gas, and at the same time, the waste gas adsorbed by the filler in adsorber b flows to the venting silencer 10 for venting through the right venting pneumatic valve 5; when adsorber a finishes adsorption, adsorber b finishes venting. At this time, the left air inlet pneumatic valve 2, the right air inlet pneumatic valve 3, the left venting pneumatic valve 4, the right venting pneumatic valve 5, the left gas production pneumatic valve 8 and the right gas production pneumatic valve 9 are closed, and the pressure equalizing pneumatic valve 6 and the pressure equalizing pneumatic valve b7 are opened. Adsorber a equalizes the pressure of adsorber b. After the pressure equalization is completed, adsorber b performs adsorption work. At this time, the right air inlet pneumatic valve 3. The left vent pneumatic valve 4 and the right gas production pneumatic valve 9 are opened, the left intake pneumatic valve 2, the right vent pneumatic valve 5, the pressure equalizing pneumatic valve 6, the pressure equalizing pneumatic valve b7 and the left gas production pneumatic valve 8 are closed, and the raw air passes through the intake pipe 16, the internal pipeline of the valve group a13 and the connecting pipe b18 into the adsorber b, and after being adsorbed by the filler in the adsorber b, it enters the internal pipeline of the valve group b14 through the connecting pipe d20, and finally outputs the product gas through the air guide pipe 19. At the same time, the waste gas adsorbed by the filler in the adsorber a passes through the left vent pneumatic valve Door 4 flows to the venting silencer 10 for venting. When adsorber b finishes adsorption, adsorber a also finishes venting. At this time, the left air inlet pneumatic valve 2, the right air inlet pneumatic valve 3, the left venting pneumatic valve 4, the right venting pneumatic valve 5, the left gas production pneumatic valve 8 and the right gas production pneumatic valve 9 are closed, and the pressure equalizing pneumatic valve 6 and the pressure equalizing pneumatic valve b7 are opened. Adsorber b equalizes the pressure of adsorber a. After the pressure equalization is completed, adsorber a performs adsorption. This cycle enables the pressure swing adsorption air separation unit to operate continuously and output product gas, where the product gas is oxygen or nitrogen.

[0036] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An integrated valve block for a pressure swing adsorption air separation unit, characterized in that: The invention comprises a valve group a (13) and a valve group b (14), wherein one end of the valve group a (13) is provided with an air inlet pipe (16), and the other end of the valve group a (13) is provided with a connecting pipe group a, and the connecting pipe group a is communicated with the air inlet of the adsorber group, and a flow pipe group a is provided in the valve group a (13), and a corresponding pneumatic valve is provided at the end of the flow pipe group a, and the air inlet pipe (16) and the connecting pipe group a are both communicated with the flow pipe group a; one end of the valve group b (14) is provided with an air guide pipe (19), and the other end of the valve group b (14) is provided with a connecting pipe group b, and the connecting pipe group b is communicated with the air outlet of the adsorber group, and a flow pipe group b is provided in the valve group b (14), and a corresponding pneumatic valve is provided at the end of the flow pipe group b, and the air guide pipe (19) and the connecting pipe group b are both communicated with the flow pipe group b, and the other end of the air guide pipe (19) is communicated with a buffer tank.

2. The integrated valve block for a pressure swing adsorption air separation unit according to claim 1, characterized in that: The adsorber group includes adsorber a and adsorber b, the connecting pipe group a includes connecting pipe a (17) and connecting pipe b (18), the connecting pipe a (17) and the connecting pipe b (18) are both connected to the flow pipe group a, and the connecting pipe a (17) is connected to the air inlet of the adsorber a, and the connecting pipe b (18) is connected to the air inlet of the adsorber b.

3. The integrated valve block for a pressure swing adsorption air separation unit according to claim 2, characterized in that: The flow pipe group a comprises a pipe a (23), a pipe b (24), a pipe c (25), a pipe d (27) and a pipe z (28); the pipe a (23), the pipe c (25) and the pipe z (28) are horizontally opened in the valve group a (13); the pipe b (24) and the pipe d (27) are vertically opened in the valve group a (13); the pipe a (23), the pipe b (24), the pipe c (25), the pipe d (27) and the pipe z (28) are interconnected; the air outlet of the air inlet pipe (16) is connected to the middle section of the pipe a (23); the connecting pipe a (17) is connected to the pipe b (24); and the connecting pipe b (18) is connected to the pipe d (27).

4. The integrated valve block for a pressure swing adsorption air separation unit according to claim 3, characterized in that: The two ends of the pipeline a (23) are respectively provided with a left air intake pneumatic valve (2) and a right air intake pneumatic valve (3), the two ends of the pipeline z (28) are respectively provided with a pressure equalizing pneumatic valve (6), and the two ends of the pipeline c (25) are respectively provided with a left air discharge pneumatic valve (4) and a right air discharge pneumatic valve (5).

5. The integrated valve block for a pressure swing adsorption air separation unit according to claim 4, characterized in that: It also includes a venting silencer (10), and the venting silencer (10) is connected to the pipeline c (25) through the pipeline e (26).

6. The integrated valve block for a pressure swing adsorption air separation unit according to claim 5, characterized in that: The air intake pipe (16) is provided with an air intake regulating valve (1).

7. The integrated valve block for a pressure swing adsorption air separation unit according to any one of claims 2 to 6, characterized in that: The connecting pipe group b includes a connecting pipe c (21) and a connecting pipe d (20), wherein the connecting pipe c (21) and the connecting pipe d (20) are both connected to the flow pipe group b, and the connecting pipe c (21) is connected to the gas outlet of the adsorber a, and the connecting pipe d (20) is connected to the gas outlet of the adsorber b.

8. The integrated valve block for a pressure swing adsorption air separation unit according to claim 7, characterized in that: The flow pipe group b comprises a pipe f (29), a pipe g (30), a pipe h (32) and a pipe k (33); the pipe f (29) and the pipe g (30) are vertically opened in the valve group b (14); the pipe h (32) and the pipe k (33) are horizontally opened in the valve group b (14); the pipe f (29), the pipe g (30), the pipe h (32) and the pipe k (33) are interconnected; the air inlet of the air guide pipe (19) is connected to the middle section of the pipe k (33); the connecting pipe c (21) is connected to the pipe f (29); and the connecting pipe d (20) is connected to the pipe g (30).

9. The integrated valve block for a pressure swing adsorption air separation unit according to claim 8, characterized in that: A connecting pipe (31) is also provided in the valve group b (14), and two ends of the connecting pipe (31) are respectively connected to the pipeline f (29) and the pipeline g (30), and the connecting pipe (31) is located above the pipeline h (32).

10. The integrated valve block for a pressure swing adsorption air separation unit according to claim 9, characterized in that: One end of the pipeline h (32) is provided with a pressure-equalizing pneumatic valve b (7), and the two ends of the pipeline k (33) are respectively provided with a left gas-producing pneumatic valve (8) and a right gas-producing pneumatic valve (9), and the air guide pipe (19) is provided with a gas-producing regulating valve (11).

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