Mechanical seal flushing system for mixed feed pump of slurry bed hydrogenation device

Abstract

The utility model relates to the technical field of petrochemical engineering, and particularly discloses a mechanical seal flushing system for a mixed feed pump of a slurry bed hydrogenation device, which comprises the mixed feed pump, a Plan32 flushing assembly, a Plan53B flushing assembly and a Plan62 flushing assembly, and the Plan32 flushing assembly, the Plan53B flushing assembly and the Plan62 flushing assembly are all communicated with mechanical seal structures at two ends of the mixed feed pump. The Plan62 flushing assembly comprises a quenching medium inlet pipeline, a quenching medium stop valve and a quenching medium pressure gauge, wherein the quenching medium stop valve and the quenching medium pressure gauge are sequentially arranged on the quenching medium inlet pipeline. Through the combination of the Plan32 flushing assembly, the Plan53B flushing assembly and the Plan62 flushing assembly, the Plan62 flushing assembly takes steam or nitrogen as a quenching medium to blow and cool the sealing end face of the atmosphere side of the Plan53B flushing assembly, mechanical seal leakage caused by coking of the end face of the atmosphere side is prevented, the reliability of the mechanical seal is enhanced, leakage accidents caused by failure of the mechanical seal are reduced, and the mechanical seal is safe and reliable. Production safety and environmental protection are guaranteed, and the service life of the mechanical seal is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of petrochemical technology, and in particular to a mechanical seal flushing system for a mixing feed pump in a slurry bed hydrogenation unit. Background Technology

[0002] Slurry-bed hydrocracking is an important process for processing heavy oil, converting residue into lighter, higher-quality oils. It boasts advantages such as strong feedstock adaptability, high conversion rate, high light oil yield, simple process, flexible operation, and simple reactor structure. In slurry-bed residue hydrocracking units, the mixing feed pump plays a crucial role. However, due to the complexity of the feed medium and harsh operating conditions, the mechanical seal structure of the mixing feed pump is susceptible to wear, corrosion, and excessively high temperatures, requiring flushing. Currently, common mechanical seal flushing methods are significantly insufficient to address the special operating conditions of the mixing feed pump in slurry-bed hydrocracking units. They fail to effectively reduce the temperature of the mechanical seal or adequately remove impurities and corrosive substances, leading to coking on the atmospheric side sealing face, resulting in leakage or failure. This affects the service life and reliability of the mechanical seal, impacting normal equipment operation and increasing operational risks and production and maintenance costs.

[0003] Therefore, it is necessary to propose a mixing feed pump mechanical seal flushing system for a slurry bed hydrogenation unit to overcome the shortcomings of the prior art. Utility Model Content

[0004] The purpose of this invention is to solve the problems in the prior art and provide a mechanical seal flushing system for the mixing feed pump of a slurry bed hydrogenation device.

[0005] The technical solution of this utility model is:

[0006] A mechanical seal flushing system for a mixing feed pump in a slurry bed hydrogenation unit includes a mixing feed pump, a Plan 32 flushing assembly, and a Plan 53B flushing assembly. Mechanical seals are installed at both ends of the mixing feed pump. The Plan 32 flushing assembly is connected to the mechanical seals at both ends of the mixing feed pump. Two Plan 53B flushing assemblies are configured, each connected to the mechanical seals at both ends of the mixing feed pump. The system also includes a Plan 62 flushing assembly, also configured in two sets, each connected to the mechanical seals at both ends of the mixing feed pump. The Plan 62 flushing assembly includes a quench medium inlet pipe and a quench medium shut-off valve and a quench medium pressure gauge sequentially installed on the quench medium inlet pipe.

[0007] Preferably, a check valve is also installed on the inlet pipeline of the quenching medium.

[0008] Preferably, the Plan32 flushing assembly includes a sealing flushing oil inlet pipe and two branch pipes. One end of each of the two branch pipes is connected to the sealing flushing oil inlet pipe, and the other end of each branch pipe is connected to the mechanical seal structure at both ends of the mixing feed pump. A sealing flushing oil flow meter and a sealing flushing oil pressure gauge are sequentially installed on the branch pipes.

[0009] Preferably, two filters connected in parallel are installed on the sealing flushing oil inlet pipeline, and sealing flushing oil shut-off valves are installed on both sides of the filters.

[0010] Preferably, the Plan53B flushing assembly includes an oil inlet pipe, an oil outlet pipe, an accumulator, a pressure pump, and a cooler. The oil inlet pipe and the oil outlet pipe are both connected to the mechanical seal structure. The cooler is located between the oil inlet pipe and the oil outlet pipe. The pressure pump and the accumulator are connected in sequence and communicate with the oil inlet pipe and the oil outlet pipe. The cooler is equipped with a cooling water inlet pipe and a cooling water return pipe.

[0011] Preferably, the Plan53B flushing assembly also includes a thermometer and a line pressure gauge, which are used to monitor the system temperature and pressure of the Plan53B flushing assembly, respectively.

[0012] Preferably, the sealing oil medium for the Plan32 flushing assembly is wax oil, the sealing flushing oil medium for the Plan53B flushing assembly is heat transfer oil or industrial white oil, and the Plan62 flushing assembly uses steam or nitrogen as the quenching medium.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] This invention combines Plan32, Plan53B, and Plan62 flushing components. Plan62 uses steam or nitrogen as a quenching medium to purge and cool the atmospheric side sealing end face of Plan53B flushing component, preventing mechanical seal leakage caused by coking on the atmospheric side end face. This enhances the reliability of the mechanical seal, reduces leakage accidents caused by mechanical seal failure, ensures production safety and environmental protection, extends the service life of the mechanical seal, reduces equipment maintenance costs and downtime, and improves production efficiency. It can meet the complex operating conditions of the mixing feed pump in a slurry bed hydrogenation unit and has broad application prospects. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model.

[0016] The components include: 1. Mixing feed pump; 101. Mechanical seal structure; 2. Quenching medium inlet pipeline; 3. Quenching medium shut-off valve; 4. Quenching medium pressure gauge; 5. Check valve; 6. Sealing flushing oil inlet pipeline; 7. Branch pipeline; 8. Sealing flushing oil flow meter; 9. Sealing flushing oil pressure gauge; 10. Filter; 11. Sealing flushing oil shut-off valve; 12. Oil inlet pipeline; 13. Oil outlet pipeline; 14. Accumulator; 15. Pressure pump; 16. Cooler; 17. Cooling water inlet pipeline; 18. Cooling water return pipeline; 19. Thermometer; 20. Pipeline pressure gauge. Detailed Implementation

[0017] To make the technical means, technical features, utility model purpose and technical effects of this utility model easier to understand, the present utility model will be further described below with reference to specific illustrations.

[0018] like Figure 1 As shown, a mechanical seal flushing system for a mixing feed pump in a slurry bed hydrogenation unit includes a mixing feed pump 1, a Plan 32 flushing assembly, a Plan 53B flushing assembly, and a Plan 62 flushing assembly. The mixing feed pump 1 is an API 610BB5 pump with an operating temperature greater than 300°C. Mechanical seal structures 101 are connected to both ends of the mixing feed pump 1 to achieve shaft end sealing. The Plan 32 flushing assembly, Plan 53B flushing assembly, and Plan 62 flushing assembly are all connected to the mechanical seal structures 101 at both ends of the mixing feed pump 1, enhancing the reliability of the mechanical seal structures 101, extending the service life of the mechanical seal structures 101, reducing leakage caused by failure of the mechanical seal structures 101, ensuring production safety, and protecting the environment.

[0019] like Figure 1As shown, the Plan 32 flushing assembly is connected to the mechanical seal structures 101 at both ends of the mixing feed pump 1. The Plan 32 flushing assembly includes a sealing flushing oil inlet pipe 6 and two branch pipes 7. One end of each branch pipe 7 is connected to the sealing flushing oil inlet pipe 6, and the other end of each branch pipe 7 is connected to the mechanical seal structures 101 at both ends of the mixing feed pump 1. The sealing oil medium of the Plan 32 flushing assembly is wax oil. A sealing flushing oil flow meter 8 and a sealing flushing oil pressure gauge 9 are installed sequentially on the branch pipes 7. The pressure is controlled by the sealing flushing oil flow meter 8. The flow rate of the sealing oil medium supplied to the mechanical seal structure 101 is controlled. The pressure in the branch pipeline 7 is observed through the sealing flushing oil pressure gauge 9. A filter 10 is installed on the sealing flushing oil inlet pipeline 6. There are two filters 10 connected in parallel. The two filters 10 serve as a backup for each other. When one filter 10 fails, the other filter 10 can ensure the normal operation of the system. A sealing flushing oil shut-off valve 11 is installed on both sides of the filter 10. The use of the two filters 10 is switched by opening and closing the sealing flushing oil shut-off valve 11.

[0020] like Figure 1 As shown, there are two Plan 53B flushing assemblies. Each Plan 53B flushing assembly is connected to the mechanical seal structure 101 at both ends of the mixing feed pump 1. The flushing medium for the Plan 53B flushing assembly is either heat transfer oil or industrial white oil. The Plan 53B flushing assembly includes an oil inlet pipe 12, an oil outlet pipe 13, an accumulator 14, a pressure pump 15, a cooler 16, a thermometer 19, and a pipeline pressure gauge 20. The oil inlet pipe 12 and the oil outlet pipe 13 are connected to the mechanical seal structure 101. The cooler 16 is installed between the oil inlet pipe 12 and the oil outlet pipe 13. The pressure pump 15 and the accumulator 14 are connected in sequence and connected to the oil inlet pipe 12 and the oil outlet pipe 13. The system temperature of the Plan53B flushing assembly is monitored by the installed thermometer 19, and the system pressure of the Plan53B flushing assembly is monitored by the pipe pressure gauge 20. When the pressure is insufficient, the pressure pump 15 is started to replenish oil and pressurize. The accumulator 14 is used to stabilize the system pressure. The cooler 16 uses demineralized water or circulating water as the cooling medium. The cooler 16 is connected to the cooling water inlet pipe 17 and the cooling water return pipe 18 to realize the circulation of the cooling medium and remove the heat generated by the circulation of the sealing flushing medium.

[0021] like Figure 1As shown, there are two sets of Plan 62 flushing components. The two sets of Plan 62 flushing components are respectively connected to the mechanical seal structure 101 at both ends of the mixing feed pump 1. The Plan 62 flushing components use steam or nitrogen as quenching medium to purge and cool the atmospheric side sealing end face of the Plan 53B flushing component, preventing sealing leakage caused by coking on the atmospheric side sealing end face. The Plan 62 flushing components include a quenching medium inlet pipe 2, a quenching medium shut-off valve 3, and a quenching medium pressure gauge 4. The quenching medium pressure gauge 4 and the quenching medium shut-off valve 3 are installed sequentially on the quenching medium inlet pipe 2. The quenching medium shut-off valve 3 controls the purging pressure of the quenching medium, and the quenching medium pressure gauge 4 observes the pressure of the quenching medium inlet pipe 2. A check valve 5 is also installed on the quenching medium inlet pipe 2 to control the flow direction of the quenching medium and prevent backflow of the quenching medium.

[0022] This invention effectively solves the problem of sealing flushing oil leakage caused by damage to the atmospheric side sealing end face of the Plan53B flushing component in the mixing feed pump 1 by combining the Plan32 flushing component, Plan53B flushing component, and Plan62 flushing component. The Plan62 flushing component uses steam or nitrogen as a quenching medium to purge and cool the atmospheric side sealing end face of the Plan53B flushing component, preventing mechanical seal leakage caused by coking on the atmospheric side end face. For this purpose, the mechanical seal structure 101 at both ends of the mixing feed pump 1 needs to be integrated into a modular structure for the three flushing schemes of Plan32 flushing component, Plan53B flushing component, and Plan62 flushing component, with interfaces reserved for each component to facilitate on-site pipe connection.

[0023] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of this utility model. All equivalent changes and modifications made in accordance with the scope of the claims of this utility model should fall within the technical scope of this utility model.

Claims

1. A mechanical seal flushing system for a mixing feed pump in a slurry bed hydrogenation unit, comprising a mixing feed pump (1), a Plan 32 flushing assembly, and a Plan 53B flushing assembly, wherein both ends of the mixing feed pump (1) are provided with mechanical seal structures (101), characterized in that: The Plan32 flushing assembly is connected to the mechanical seal structure (101) at both ends of the mixing feed pump (1). The Plan53B flushing assembly is configured in two sets, and the two sets of Plan53B flushing assemblies are respectively connected to the mechanical seal structure (101) at both ends of the mixing feed pump (1). The Plan62 flushing assembly is also included. The Plan62 flushing assembly is configured in two sets, and the two sets of Plan62 flushing assemblies are respectively connected to the mechanical seal structure (101) at both ends of the mixing feed pump (1). The Plan62 flushing assembly includes a quench medium inlet pipe (2) and a quench medium shut-off valve (3) and a quench medium pressure gauge (4) sequentially arranged on the quench medium inlet pipe (2).

2. The mixing feed pump mechanical seal flushing system of the slurry bed hydrogenation unit according to claim 1, characterized in that: A check valve (5) is also installed on the quench medium inlet pipe (2).

3. The mixing feed pump mechanical seal flushing system for the slurry bed hydrogenation unit according to claim 1, characterized in that: The Plan32 flushing assembly includes a sealing flushing oil inlet pipe (6) and two branch pipes (7). One end of each of the two branch pipes (7) is connected to the sealing flushing oil inlet pipe (6), and the other end of each branch pipe (7) is connected to the mechanical seal structure (101) at both ends of the mixing feed pump (1). A sealing flushing oil flow meter (8) and a sealing flushing oil pressure gauge (9) are sequentially installed on the branch pipes (7).

4. The mixing feed pump mechanical seal flushing system of the slurry bed hydrogenation unit according to claim 3, characterized in that: Two parallel filters (10) are installed on the sealing flushing oil inlet pipeline (6), and sealing flushing oil shut-off valves (11) are installed on both sides of the filters (10).

5. The mixing feed pump mechanical seal flushing system for the slurry bed hydrogenation unit according to claim 1, characterized in that: The Plan53B flushing assembly includes an oil inlet pipe (12), an oil outlet pipe (13), an accumulator (14), a pressure pump (15), and a cooler (16). The oil inlet pipe (12) and the oil outlet pipe (13) are both connected to the mechanical seal structure (101). The cooler (16) is located between the oil inlet pipe (12) and the oil outlet pipe (13). The pressure pump (15) and the accumulator (14) are connected in sequence and communicate with the oil inlet pipe (12) and the oil outlet pipe (13). The cooler (16) is provided with a cooling water inlet pipe (17) and a cooling water return pipe (18).

6. The mixing feed pump mechanical seal flushing system of the slurry bed hydrogenation unit according to claim 1, characterized in that: The Plan53B flushing assembly also includes a thermometer (19) and a pipeline pressure gauge (20), which are used to monitor the system temperature and pressure of the Plan53B flushing assembly, respectively.

7. The mixing feed pump mechanical seal flushing system for a slurry bed hydrogenation unit according to claim 1, characterized in that: The Plan32 flushing assembly uses wax oil as the sealing oil medium, the Plan53B flushing assembly uses heat transfer oil or industrial white oil as the sealing flushing oil medium, and the Plan62 flushing assembly uses steam or nitrogen as the quenching medium.

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