Acrylonitrile catalyst safe replenishing system

Abstract

The utility model discloses a safe replenishing system for an acrylonitrile catalyst, and belongs to the technical field of acrylonitrile production. According to the technical scheme, the device comprises a catalyst supplementing tank, a reactor, a steam-jet pump, a catalyst separating tank and a controller, the top of the catalyst supplementing tank is connected with a cyclone separator, a catalyst circulating pipeline is connected between the catalyst supplementing tank and the cyclone separator, and an upper outlet of the cyclone separator is connected with the steam-jet pump through a pipeline; the steam jet pump is connected with a catalyst separation tank through a catalyst separation pipeline; a pressurized air inlet pipeline is also arranged at the top of the catalyst supplementing tank; the bottom of the catalyst supplementing tank is connected with a reactor through a reactor feeding pipeline; the bottom of the catalyst supplementing tank is further connected with a loose air supply pipeline, and a control valve is arranged on the loose air supply pipeline. According to the utility model, on-line accurate replenishing of the catalyst is realized, meanwhile, recovery of the catalyst entrained in a gas phase in a catalyst extraction process can be reduced, and pollution is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of acrylonitrile production, and in particular relates to a safe acrylonitrile catalyst supplement system. Background Art

[0002] Acrylonitrile is an important organic chemical raw material, widely used in the synthesis of synthetic fibers, plastics, rubber and other materials. Currently, most acrylonitrile is produced through the oxidation of propylene ammonia. After long-term use in industrial equipment, part of the catalyst will flow out with the reaction products, and the activity of part of the catalyst will gradually decrease. Due to the high price of catalysts, the whole tower is rarely replaced for economic reasons. Industry usually adopts the method of adding catalysts or regenerating catalysts with reduced activity to maintain reaction performance. Some current adding devices are difficult to add accurately, and there is a problem that the conical tip of the catalyst in the adding tank is easily blocked, resulting in poor catalyst outflow. The catalyst entrained in the gas phase during the addition process is directly discharged into the air, which will also pollute the air. Utility Model Content

[0003] The utility model provides a safe acrylonitrile catalyst replenishing system, which realizes accurate online replenishing of the catalyst and can reduce the recovery of the catalyst entrained in the gas phase during the catalyst extraction process, thereby reducing pollution.

[0004] The technical solution of the utility model is:

[0005] The acrylonitrile catalyst safety feeding system comprises a catalyst feeding tank, a reactor, a steam jet pump, a catalyst separation tank and a controller, wherein the steam jet pump is electrically connected to the controller; a cyclone separator is connected to the top of the catalyst feeding tank, a catalyst circulation pipeline is connected between the catalyst feeding tank and the cyclone separator, an upper outlet of the cyclone separator is connected to the steam jet pump through a pipeline, the steam jet pump is connected to a steam inlet pipeline, a steam inlet valve is arranged on the steam inlet pipeline, and the steam inlet valve is electrically connected to the controller; the steam jet pump is connected to the catalyst separation tank through a catalyst separation pipeline, and a flushing water inlet pipeline is connected to the catalyst separation tank; the catalyst separation tank is also connected to an overflow pipeline and a gas discharge pipeline, and the catalyst feeding tank is connected to a catalyst storage tank through a pipeline; a cyclone separator and the steam jet pump are connected between the catalyst feeding tank and the catalyst storage tank. A hand valve is arranged on the pipeline; a pressurized air inlet pipeline is also arranged on the top of the catalyst replenishing tank, and a self-operated regulating valve is arranged on the pressurized air inlet pipeline, and the self-operated regulating valve is electrically connected to the controller; the bottom of the catalyst replenishing tank is connected to the reactor through the reactor feeding pipeline; the reactor feeding pipeline is divided into feeding pipeline one, feeding pipeline two and feeding pipeline three, a sight glass is arranged between feeding pipeline one and feeding pipeline two, feeding pipeline three is connected to the main air supply pipeline of instrument air, and an auxiliary air supply pipeline is also connected between the main air supply pipeline of instrument air and the reactor feeding pipeline, and solenoid valves are arranged on feeding pipeline one, feeding pipeline two, main air supply pipeline of instrument air and auxiliary air supply pipeline, and the solenoid valves are electrically connected to the controller; a loosening air supply pipeline is also connected to the bottom of the catalyst replenishing tank, and a control valve is arranged on the loosening air supply pipeline.

[0006] Preferably, the catalyst separation pipeline is also connected with a metal hose, which has good pressure resistance and enhances the service life of the pipeline.

[0007] Preferably, one end of the auxiliary air supply pipeline is connected to the main air supply pipeline for instrument air, and the other end is connected to the pipeline between the first feeding pipeline and the second feeding pipeline.

[0008] Preferably, the bottoms of the catalyst separation tank and the catalyst replenishing tank are both conical, a sewage outlet is provided at the bottom of the conical structure of the catalyst separation tank, and an anti-sticking component is provided inside the conical structure.

[0009] Preferably, the anti-sticking component includes an anti-sticking fixing plate, which has an upper surface and a lower surface. The lower surface of the anti-sticking fixing plate is fixed on the inner wall of the conical structure, and the anti-sticking fixing plate completely covers the inner wall of the conical structure. The upper surface of the anti-sticking fixing plate is a smooth surface, and the friction resistance of the upper surface of the anti-sticking fixing plate is small, which is more conducive to the sliding and discharge of solid matter in sewage.

[0010] Preferably, a flow limiting orifice plate is further provided on the loosening air supply duct, and the flow limiting orifice plate is provided with flow limiting holes.

[0011] Compared with the prior art, the utility model has the following beneficial effects:

[0012] 1. The catalyst safety replenishment system of the utility model can replenish the pressure in the catalyst replenishment tank through the self-operated regulating valve on the pressurized air supply pipeline, so that the pressure in the catalyst replenishment tank remains stable, thereby accurately controlling the amount of catalyst replenishment each time and reducing the error of human control;

[0013] 2. The negative pressure generated by the steam jet pump can automatically extract the catalyst in the catalyst storage tank into the catalyst replenishing tank, making the operation more convenient;

[0014] 3. The setting of the loosening air supply pipeline and the flow-limiting orifice plate can loosen the catalyst solids gathered at the conical bottom of the catalyst replenishing tank and reduce blockage. At the same time, the flow-limiting orifice plate limits the airflow of the loosening air so that it does not cause the catalyst particles to fly up, thereby ensuring the stable output of the catalyst.

[0015] 4. The anti-sticking fixing plate is set on the catalyst separation tank to reduce the blockage at the bottom of the separation tank. The overflow pipeline can continuously output the material in the catalyst separation tank when the bottom of the catalyst separation tank is blocked, ensuring the normal operation of the system.

[0016] 5. The setting of the reactor feeding pipeline, the main instrument air supply pipeline, the auxiliary air supply pipeline and the sight glass can timely adjust the output of the catalyst in the catalyst replenishing tank according to the situation of catalyst addition, realize the accurate replenishment of the catalyst, reduce the waste of the catalyst and save production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the utility model.

[0018] Figure 2 It is a structural schematic diagram of the catalyst separation tank of the utility model.

[0019] Figure 3 It is a structural schematic diagram of the current limiting orifice plate of the utility model.

[0020] In the figure, 1. catalyst replenishing tank; 2. reactor; 3. steam jet pump; 4. catalyst separation tank; 401. sewage outlet; 402. anti-sticking fixing plate; 5. cyclone separator; 6. catalyst circulation pipeline; 7. steam inlet pipeline; 8. steam inlet valve; 9. catalyst separation pipeline; 10. flushing water inlet pipeline; 11. overflow pipeline; 12. gas exhaust pipeline; 13. catalyst storage tank; 14. pressurized air inlet pipeline; 15. feed pipeline one; 16. feed pipeline two; 17. feed pipeline three; 18. sight glass; 19. instrument air main supply pipeline; 20. auxiliary supply pipeline; 21. loose air supply pipeline; 22. metal hose; 23. flow limiting orifice plate; 24. flow limiting hole. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0022] Example 1

[0023] like Figure 1-3 As shown, this embodiment provides a safe acrylonitrile catalyst replenishment system, including a catalyst replenishment tank 1, a reactor 2, a steam jet pump 3, a catalyst separation tank 4 and a controller, the steam jet pump 3 is electrically connected to the controller; a cyclone separator 5 is connected to the top of the catalyst replenishment tank 1, a catalyst circulation pipeline 6 is connected between the catalyst replenishment tank 1 and the cyclone separator 5, the upper outlet of the cyclone separator 5 is connected to the steam jet pump 3 through a pipeline, the steam jet pump 3 is connected to a steam inlet pipeline 7, the steam inlet pipeline 7 is provided with a steam inlet valve 8, and the steam inlet valve 8 is electrically connected to the controller; the steam jet pump 3 is connected to the catalyst separation tank 4 through a catalyst separation pipeline 9, and the catalyst separation pipeline 9 is connected to a flushing water inlet pipeline 10; the catalyst separation pipeline 9 is also connected to a metal hose 22, and the metal hose has good pressure resistance, Enhance the service life of the pipeline; the catalyst separation tank 4 is also connected to the overflow pipeline 11 and the gas exhaust pipeline 12, the bottom of the catalyst separation tank 4 and the catalyst replenishing tank 1 are both conical, the bottom of the conical structure of the catalyst separation tank 4 is provided with a sewage outlet 401, and an anti-sticking component is provided inside the conical structure; the anti-sticking component includes an anti-sticking fixed plate 402, the anti-sticking fixed plate has an upper surface and a lower surface, the lower surface of the anti-sticking fixed plate is fixed on the inner wall of the conical structure, the anti-sticking fixed plate completely covers the inner wall of the conical structure, the upper surface of the anti-sticking fixed plate is a smooth surface, the friction resistance of the upper surface of the anti-sticking fixed plate is small, and it is more conducive to the sliding and discharge of solids in sewage. In specific applications, the anti-sticking fixed plate can be made of stainless steel plate, and the stainless steel plate can be welded and connected to multiple fixings, so as to realize the connection and fixation of the anti-sticking fixed plate and the inner wall of the conical structure.

[0024] The catalyst replenishing tank 1 is connected to the catalyst storage tank 13 through a pipeline; a hand valve is provided on the pipeline between the cyclone separator 5 and the steam jet pump 3; a pressurized air inlet pipeline 14 is also provided on the top of the catalyst replenishing tank 1, and a self-operated regulating valve is provided on the pressurized air inlet pipeline 14, and a pressure regulator of model MR95H produced by FISHER is adopted, and the self-operated regulating valve is electrically connected to the controller; the bottom of the catalyst replenishing tank 1 is connected to the reactor 2 through the reactor feeding pipeline; the reactor feeding pipeline is divided into a feeding pipeline 1 15, a feeding pipeline 2 16 and a feeding pipeline 3 17, and a sight glass 18 is provided between the feeding pipeline 15 and the feeding pipeline 2 16 , the feed pipeline 3 17 is connected to the instrument air main air supply pipeline 19, and the instrument air main air supply pipeline 19 and the reactor feed pipeline are also connected with an auxiliary air supply pipeline 20, one end of the auxiliary air supply pipeline 20 is connected to the instrument air main air supply pipeline 19, and the other end is connected to the pipeline between the feed pipeline 1 15 and the feed pipeline 2 16, and the feed pipeline 1 15, the feed pipeline 2 16, the instrument air main air supply pipeline 19 and the auxiliary air supply pipeline 20 are all provided with electromagnetic valves, and the electromagnetic valves are all electrically connected to the controller; the bottom of the catalyst replenishing tank 1 is also connected to a loose air supply pipeline 21, and a control valve is provided on the loose air supply pipeline 21, and the control valve is electrically connected to the controller. A limiting flow orifice plate 23 is also provided on the loose air supply pipeline 21, and the limiting flow plate is provided on the DN15 pipeline, and the limiting flow orifice plate is provided with a limiting flow hole 24, and the limiting flow hole 24.

[0025] Working process: open the manual valve on the pipeline between the steam jet pump 3 and the cyclone separator 5, and generate negative pressure in the catalyst replenishing tank 1 through the steam jet pump 3, and suck the catalyst in the catalyst storage tank 13 into the catalyst replenishing tank 1. Since the catalyst is expensive, the production cost can be reduced to a certain extent. The cyclone separator recovers a part of the catalyst taken away by the negative pressure and re-enters the catalyst replenishing tank 1. Close the manual valve on the pipeline between the steam jet pump 3 and the cyclone separator 5. The pressurized air inlet pipeline 14 can also be used as a vacuum breaking pipeline. After the catalyst is extracted under negative pressure, the vacuum of the entire device is broken, and the pressure of the entire device is changed to a positive pressure of 0.3MPa, thereby avoiding the deactivation of the catalyst due to unnecessary water vapor brought by the direct introduction of air into the device. The valve on the loose air supply line 21 is always in the open state under normal pressure. First, open the solenoid valve on the instrument air main supply line 19 to ensure the air supply of the instrument air main supply line 19, and then open the solenoid valve on the feed line 15 to let the catalyst fall into the pipeline with the sight glass 18. After the sight glass 18 is full of catalyst, close the solenoid valve on the feed line 15, and then open the solenoid valves on the auxiliary air supply line 20 and the feed line 2 16 to feed the catalyst in the feed line 2 16 into the reactor 2. When closing, first close the solenoid valve on the feed line 2 16, and then close the solenoid valve on the auxiliary air supply line 20, and finally close the solenoid valve on the instrument air main supply line 19 to complete a single feeding. As the catalyst in the catalyst replenishing tank 1 is continuously reduced, the pressure in the catalyst replenishing tank 1 will Reduce, by adjusting the self-operated regulating valve on the pressurized air inlet pipeline 14, maintain the pressure in the catalyst replenishing tank 1 at 0.3MPa to ensure the accuracy of feeding, repeat the above operation for multiple feedings, after multiple feedings, the catalyst carried away by the negative pressure goes along the pipeline to the catalyst separation pipeline 9, the catalyst carried away by the negative pressure and the water inlet pipeline 10 enter the catalyst separation tank 4, the sewage in the catalyst separation tank 4 is discharged to the sewage treatment plant for further treatment, the structure of the anti-sticking fixed plate 402 can effectively prevent the sewage outlet 401 from being blocked, if the sewage outlet 401 is blocked, when the sewage rises to the height of the overflow pipeline 11, the sewage is discharged through the overflow pipeline 11, which effectively prevents the environmental pollution caused by directly discharging the catalyst adsorbed by negative pressure into the air in the prior art.

[0026] Although the present invention is described in detail by referring to the accompanying drawings and in combination with the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person skilled in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions shall be within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. The acrylonitrile catalyst safe addition system is characterized by: It comprises a catalyst replenishing tank (1), a reactor (2), a steam jet pump (3), a catalyst separation tank (4) and a controller, wherein the steam jet pump (3) is electrically connected to the controller; The top of the catalyst replenishing tank (1) is connected to a cyclone separator (5); a catalyst circulation pipeline (6) is connected between the catalyst replenishing tank (1) and the cyclone separator (5); the upper outlet of the cyclone separator (5) is connected to a steam jet pump (3) through a pipeline; the steam jet pump (3) is connected to a steam inlet pipeline (7); a steam inlet valve (8) is provided on the steam inlet pipeline (7); the steam inlet valve (8) is electrically connected to a controller; the steam jet pump (3) is connected to a catalyst separation tank (4) through a catalyst separation pipeline (9); a flushing water inlet pipeline (10) is connected to the catalyst separation tank (4); an overflow pipeline (11) and a gas exhaust pipeline (12) are also connected to the catalyst separation tank (4); the catalyst replenishing tank (1) is connected to a catalyst storage tank (13) through a pipeline; a hand valve is provided on the pipeline between the cyclone separator (5) and the steam jet pump (3); The catalyst replenishing tank (1) is also provided with a pressurized air inlet pipeline (14) on the top, and a self-operated regulating valve is provided on the pressurized air inlet pipeline (14), and the self-operated regulating valve is electrically connected to the controller; the bottom of the catalyst replenishing tank (1) is connected to the reactor (2) through a reactor feeding pipeline; the reactor feeding pipeline is divided into a feeding pipeline 1 (15), a feeding pipeline 2 (16) and a feeding pipeline 3 (17), and the feeding pipeline 1 (15) and the feeding pipeline 3 (17) are connected to each other. A sight glass (18) is provided between the material pipeline 2 (16), the material feeding pipeline 3 (17) is connected to the instrument air main air supply pipeline (19), an auxiliary air supply pipeline (20) is also connected between the instrument air main air supply pipeline (19) and the reactor material feeding pipeline, and electromagnetic valves are provided on the material feeding pipeline 1 (15), the material feeding pipeline 2 (16), the instrument air main air supply pipeline (19) and the auxiliary air supply pipeline (20), and the electromagnetic valves are electrically connected to the controller; The bottom of the catalyst replenishing tank (1) is also connected to a loose air supply pipeline (21), and a control valve is arranged on the loose air supply pipeline (21).

2. The acrylonitrile catalyst safe addition system according to claim 1, characterized in that: The catalyst separation pipeline (9) is also connected to a metal hose (22), which has good pressure resistance and increases the service life of the pipeline.

3. The acrylonitrile catalyst safe addition system according to claim 1, characterized in that: One end of the auxiliary air supply pipeline (20) is connected to the instrument air main air supply pipeline (19), and the other end is connected to the pipeline between the material feeding pipeline 1 (15) and the material feeding pipeline 2 (16).

4. The acrylonitrile catalyst safe addition system according to claim 1, characterized in that: The bottoms of the catalyst separation tank (4) and the catalyst replenishing tank (1) are both conical, a sewage outlet (401) is provided at the bottom of the conical structure of the catalyst separation tank (4), and an anti-sticking component is provided inside the conical structure.

5. The acrylonitrile catalyst safe addition system according to claim 4, characterized in that: The anti-sticking component includes an anti-sticking fixing plate (402), which has an upper surface and a lower surface. The lower surface of the anti-sticking fixing plate is fixed on the inner wall of the conical structure. The anti-sticking fixing plate completely covers the inner wall of the conical structure. The upper surface of the anti-sticking fixing plate is a smooth surface.

6. The acrylonitrile catalyst safe addition system according to claim 1, characterized in that: A flow limiting orifice plate (23) is also provided on the loosening air supply pipeline (21), and the flow limiting orifice plate is provided with a flow limiting hole (24).

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