Closed drainage system of polypropylene device

Abstract

The utility model discloses a closed drainage system of a polypropylene device, and belongs to the technical field of polypropylene. According to the technical scheme, the device comprises a propylene recovery tank, a propylene recovery coalescer, a propylene recovery compressor interstage separator, a closed discharge liquid separation tank and a steamer washing tower, the closed discharge liquid separation tank is connected with a drainage inflow pipeline, the closed discharge liquid separation tank is connected with the steamer washing tower through a liquid separation tank water outlet pipeline, the closed discharge liquid separation tank is further provided with a sewage discharge pipeline, a gas phase balance pipeline, a nitrogen pressure supplementing pipeline and a low tile pressure relief pipeline, and the gas phase balance pipeline is communicated with the steamer washing tower; and the steamer washing tower is connected with a steamer process gas inlet pipeline and a self-circulation pipeline. According to the utility model, the process flow is configured on site for the propylene recovery compressor interstage separator and the propylene recovery tank, the separated water is discharged to the closed discharge liquid separation tank, and is pressurized by the pump to be further heated and washed by the steamer washing tower, so that the problem of peculiar smell of discharged water is thoroughly solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of polypropylene production, and in particular relates to a closed liquid discharge system for a polypropylene device. Background Art

[0002] In the production process of polypropylene SPG, propylene is used as a monomer, and polypropylene is obtained through prepolymerization, slurry polymerization, and gas phase polymerization, and then polypropylene powder is obtained through gas-solid separation, steaming, drying, powder transportation and other steps. The steaming and washing system compresses the recovered propylene and sends it to the external delivery device of the recovered propylene tank. Since the recovered propylene carries water vapor, after compression, the separator between stages of the recovered propylene compressor and the recovered propylene tank need to be drained regularly. In the existing technology, water is often discharged directly, resulting in a strong odor on site, which does not meet the safety and environmental protection requirements. If the drainage is recycled and processed additionally, the production cost will increase. Utility Model Content

[0003] The utility model provides a closed liquid drainage system for a polypropylene device. By configuring a process flow on-site for a propylene recovery compressor interstage separator and a propylene recovery tank, precipitated water is discharged to a closed discharge liquid separation tank, and is pressurized by a machine pump and sent to a steamer washing tower for further heating and washing, and the entrained propylene and propane are recovered, thus completely solving the problem of drainage odor.

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

[0005] A closed drainage system for a polypropylene device comprises a propylene recovery tank, a propylene recovery coalescer, a propylene recovery compressor interstage separator, a closed discharge liquid separator tank and a steamer washing tower; the closed discharge liquid separator tank is connected with a drainage inflow pipeline, and the drainage inflow pipeline is connected with the propylene recovery tank through the propylene recovery tank drainage pipeline; the drainage inflow pipeline is connected with the propylene recovery coalescer through the coalescer drainage pipeline; the drainage inflow pipeline is connected with the propylene recovery compressor interstage separator through the inlet separator drainage pipeline; the closed discharge liquid separator tank and the steamer washing tower are connected through the liquid separator tank outlet pipeline, the closed discharge liquid separator tank is also provided with a sewage discharge pipeline, a gas phase balance pipeline, a nitrogen pressure supplement pipeline and a low-wattage pressure relief pipeline, and the gas phase balance pipeline is connected with the steamer washing tower; the steamer washing tower is connected with the steamer process gas inlet pipeline and the self-circulation pipeline.

[0006] Preferably, the water outlet pipeline of the liquid separation tank is provided with a centrifugal pump.

[0007] Preferably, the closed discharge liquid separation tank is also connected to a safety pipeline, and a safety valve is provided on the safety pipeline.

[0008] Preferably, a circulation pump and a control valve are provided on the self-circulation pipeline.

[0009] Preferably, control valves are provided on the drainage pipeline of the propylene recovery tank and the drainage pipeline of the inlet separator.

[0010] Preferably, two groups of propylene recovery coalescers are provided, and three groups of propylene recovery compressor interstage separators are provided.

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

[0012] 1. The utility model discharges the water precipitated from the interstage separator of the propylene recovery compressor and the propylene recovery tank to the steam washing tower. Through heating and further washing, the water discharged from the steam washing tower has no odor, avoiding the safety and environmental protection problems of the discharge of the interstage separator tank of the propylene recovery compressor and the propylene recovery tank.

[0013] 2. The setting of nitrogen pressure-compensating pipeline can realize the self-pressure function of liquid discharge, reduce the power consumption of centrifugal pump startup, and ensure the purging and replacement of equipment and pipeline maintenance.

[0014] 3. The setting of safety pipelines and low-wattage pressure relief pipelines can effectively prevent overpressure in the drainage system of the propylene recovery tank, propylene recovery agglomerator and interstage separator of the propylene recovery compressor, thus ensuring system safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the utility model.

[0016] In the figure, 1. Propylene recovery tank; 2. Propylene recovery coalescer; 3. Propylene recovery compressor interstage separator; 4. Closed discharge separator tank; 5. Steam evaporator washing tower; 6. Drainage inflow pipeline; 7. Propylene recovery tank drainage pipeline; 8. Coalescer drainage pipeline; 9. Inlet separator drainage pipeline; 10. Separator tank water outlet pipeline; 11. Sewage discharge pipeline; 12. Gas phase balance pipeline; 13. Nitrogen pressure replenishment pipeline; 14. Low-wattage pressure relief pipeline; 15. Steam evaporator process gas inlet pipeline; 16. Self-circulation pipeline; 17. Safety pipeline. DETAILED DESCRIPTION

[0017] 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.

[0018] Example 1

[0019] like Figure 1As shown, this embodiment provides a closed drainage system for a polypropylene device, including a propylene recovery tank 1, two groups of propylene recovery coalescers 2, three groups of propylene recovery compressor interstage separators 3, a closed discharge liquid separator tank 4 and a steamer washing tower 5; the closed discharge liquid separator tank 4 is connected to a drainage inlet pipeline 6, and the drainage inlet pipeline 6 is connected to the propylene recovery tank 1 through a propylene recovery tank drainage pipeline 7; the drainage inlet pipeline 6 is connected to the propylene recovery coalescer 2 through a coalescer drainage pipeline 8; the drainage inlet pipeline 6 is connected to the propylene recovery compressor interstage separator 3 through an inlet separator drainage pipeline 9; the closed discharge liquid separator tank 4 and the steamer washing tower 5 are ... propylene recovery tank drainage pipeline 8; the drainage inlet pipeline 6 is connected to the propylene recovery compressor interstage separator 3 through a propylene recovery tank drainage pipeline 9; the closed discharge liquid separator tank 4 and the steamer washing tower 5 are connected to the propylene recovery tank 1 through a propylene recovery tank drainage pipeline 7; the drainage inlet pipeline 6 is connected to the propylene recovery tank 1 through a propylene recovery tank drainage pipeline 7; the drainage inlet pipeline 6 is connected to the propylene recovery tank 1 through a propylene recovery tank drainage pipeline 7; the drainage inlet pipeline 6 is connected to the propylene recovery tank 1 through a propylene recovery tank drainage pipeline 7; the drainage inlet pipeline 6 is connected to the propylene recovery tank 1 through a The washing towers 5 are connected through a separator tank outlet pipe 10. The closed discharge separator tank 4 is also provided with a sewage discharge pipe 11, a gas phase balance pipe 12, a nitrogen pressure replenishment pipe 13, a low-wattage pressure relief pipe 14 and a safety pipe 17. The safety pipe 17 is provided with a safety valve. The separator tank outlet pipe 10 is provided with a centrifugal pump. The gas phase balance pipe 12 is connected to the steamer washing tower 5; the steamer washing tower 5 is connected with a steamer process gas inlet pipe 15 and a self-circulation pipe 16. The self-circulation pipe 16 is provided with a circulation pump and a control valve. The propylene recovery tank drainage pipe 7 and the inlet separator drainage pipe 9 are both provided with control valves.

[0020] Working process: water and water vapor from the propylene recovery tank 1, the propylene recovery coalescer 2 and the propylene recovery compressor interstage separator 3 enter the closed discharge separator tank 4 for temporary storage, the steam in the closed discharge separator tank 4 enters the steamer process gas inlet pipeline 15 through the gas phase balance pipeline 12, and then enters the steamer washing tower 5, the water in the closed discharge separator tank 4 is centrifugally separated by a centrifugal pump, the sewage is discharged through the sewage discharge pipeline 11, and the other water enters the steamer washing tower 5, after heating and further washing, the water discharged from the steamer washing tower 5 has no odor, thereby avoiding the safety and environmental protection problems of the propylene recovery compressor interstage separator and the propylene recovery tank discharge.

[0021] 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. A closed drainage system for a polypropylene device, characterized in that: It comprises a propylene recovery tank (1), a propylene recovery coalescer (2), a propylene recovery compressor interstage separator (3), a closed discharge liquid separator tank (4) and a steamer washing tower (5); The closed discharge liquid separation tank (4) is connected to a drainage inflow pipeline (6), and the drainage inflow pipeline (6) is connected to the propylene recovery tank (1) through a propylene recovery tank drainage pipeline (7); The drainage inflow pipeline (6) is connected to the propylene recovery coalescer (2) through the coalescer drainage pipeline (8); The drainage inflow pipeline (6) is connected to the interstage separator (3) of the propylene recovery compressor through the inlet separator drainage pipeline (9); The closed discharge liquid separator tank (4) and the steamer washing tower (5) are connected via a liquid separator tank outlet pipe (10); the closed discharge liquid separator tank (4) is also provided with a sewage discharge pipe (11), a gas phase balance pipe (12), a nitrogen pressure replenishment pipe (13) and a low-wattage pressure relief pipe (14); the gas phase balance pipe (12) is connected to the steamer washing tower (5); The steamer scrubber (5) is connected to a steamer process gas inlet pipeline (15) and a self-circulating pipeline (16).

2. The closed drainage system for a polypropylene device according to claim 1, characterized in that: The water outlet pipeline (10) of the liquid separation tank is provided with a centrifugal pump.

3. The closed drainage system for a polypropylene device according to claim 1, characterized in that: The closed discharge liquid separation tank (4) is also connected to a safety pipeline (17), and a safety valve is provided on the safety pipeline (17).

4. The closed drainage system for a polypropylene device according to claim 1, characterized in that: A circulation pump and a control valve are provided on the self-circulating pipeline (16).

5. The closed drainage system for a polypropylene device according to claim 1, characterized in that: Control valves are provided on the drainage pipeline (7) of the propylene recovery tank and the drainage pipeline (9) of the inlet separator.

6. The closed drainage system for a polypropylene device according to claim 1, characterized in that: Two groups of propylene recovery coalescers (2) are provided, and three groups of propylene recovery compressor interstage separators (3) are provided.

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