A centrifugal pump sealing liquid recycling system

Abstract

The utility model discloses a centrifugal pump machine seal sealing liquid recycling system, including a normal pressure tank, a sealing liquid circulation pump and a machine seal flushing water pipeline; the water outlet of the normal pressure tank is connected to the sealing liquid circulation pump through a pipeline; the sealing liquid circulation pump is connected to the flushing pipeline of each alkali liquid circulation pump through the machine seal flushing water pipeline; the flushing pipeline of each alkali liquid circulation pump is connected to the normal pressure tank through a flushing water return pipe. The flushing return water of each alkali liquid circulation pump is recovered by the normal pressure tank, and then recycled as machine seal flushing water. Through this system, the sealing liquid in the original device can be fully recovered, and then transported to each alkali liquid circulation pump machine seal through the sealing liquid circulation pump, avoiding the waste of the sealing liquid, performing effective recovery, and reducing the equipment operation cost.

Description

Technical Field

[0001] The utility model belongs to the technical field of polysilicon production, and in particular relates to a centrifugal pump machine sealing liquid recycling system. Background Art

[0002] The silane gas washing tower bottom is a 5% NaOH aqueous solution which is pressurized to 0.8MPa by an alkali liquid circulation pump and sprayed to the top of the tower to absorb silane gas. Alkaline liquid absorbs silane gas for a long time to produce sodium silicate. Sodium silicate enters the centrifugal pump seal and causes irreversible damage to the seal. The centrifugal pump selection is based on PAI610 centrifugal pumps for petroleum, heavy chemical and natural gas industries. The seal design is based on API682 shaft seal system of centrifugal rotary pumps, and double-end seals (Plan54 flushing scheme) are adopted. The traditional seal flushing scheme Plan54 is to provide clean liquid to the sealing chamber with an external pressurized isolation liquid storage tank or system. The circulation is completed by an external pump or pressure system. The pressure of the storage tank is greater than the pressure of the sealed process medium. In the traditional seal flushing scheme Plan54, the sealing liquid is directly discharged after the seal circulation, resulting in the consumption of sealing liquid. Summary of the invention

[0003] Purpose of the utility model: The technical problem to be solved by the utility model is to provide a centrifugal pump sealing liquid recycling system in view of the shortcomings of the prior art, so as to achieve efficient recovery of the sealing liquid and reduce the consumption of the sealing liquid in the exhaust gas recovery.

[0004] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0005] A centrifugal pump machine seal sealing liquid recycling system includes a normal pressure tank, a sealing liquid circulation pump and a machine seal flushing water pipeline; the water outlet of the normal pressure tank is connected to the sealing liquid circulation pump through a pipeline; the sealing liquid circulation pump is connected to the flushing pipeline of each alkali liquid circulation pump through the machine seal flushing water pipeline; the flushing pipeline of each alkali liquid circulation pump is connected to the normal pressure tank through a flushing water return pipe. The flushing return water of each alkali liquid circulation pump is recovered through the normal pressure tank and then recycled as machine seal flushing water.

[0006] Furthermore, the mechanical seal flushing water pipeline includes a main pipe and branch pipes connected to the flushing pipelines of each alkali solution circulation pump.

[0007] Furthermore, a flushing pipeline is also provided on the sealing liquid circulation pump, the water inlet of the flushing pipeline is connected to the mechanical seal flushing water pipeline, and the water outlet is connected to the atmospheric pressure tank through the flushing return pipe of the sealing liquid circulation pump, thereby simultaneously recovering the mechanical seal flushing water of the sealing liquid circulation pump.

[0008] Furthermore, the flushing water return pipe and the blocking liquid circulation pump flushing return pipe are combined into a main pipe and then connected to the atmospheric pressure tank together.

[0009] Furthermore, the water outlet of the blocking liquid circulation pump is directly connected to the atmospheric pressure tank through a minimum continuous flow pipeline to prevent the blocking liquid circulation pump from being blocked when it is first started.

[0010] Furthermore, the mechanical seal flushing water pipeline and the minimum continuous flow pipeline are connected in parallel at the water outlet of the sealing liquid circulation pump.

[0011] Furthermore, a check valve is provided at the water outlet of the blocking liquid circulation pump.

[0012] Furthermore, the atmospheric pressure tank is also connected to the leaching pipeline of the silane gas leaching tower through a water replenishment pipeline, and the washing water on the leaching pipeline is used as the water replenishment of the atmospheric pressure tank.

[0013] Furthermore, a float switch is also provided in the atmospheric pressure tank to realize automatic liquid replenishment.

[0014] Furthermore, on the flushing pipeline of each alkali solution circulation pump, an inlet hand valve is arranged at the front end of the alkali solution circulation pump, and a recovery hand valve is arranged at the rear end of the alkali solution circulation pump. Beneficial Effects

[0015] Through this system, the sealing liquid in the original device can be fully recovered, and then transported to each alkali liquid circulation pump seal through the sealing liquid circulation pump, avoiding the waste of sealing liquid, effectively recovering it and reducing the operating cost of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods, and the above and / or other advantages of the present invention will become more clear.

[0017] Figure 1 It is a schematic diagram of the overall structure of the centrifugal pump sealing liquid recycling system.

[0018] Wherein, each reference numeral represents:

[0019] 10-normal pressure tank; 20-sealing liquid circulation pump; 30-mechanical seal flushing water pipeline; 40-flushing water return pipe; 50-sealing liquid circulation pump flushing return pipe; 60-minimum continuous flow pipeline; 70-check valve; 80-water supply pipeline; 90-rinsing pipeline; 100-alkali solution circulation pump; 101-rinsing pipeline; 102-inlet manual valve; 103-recovery manual valve; 200-silane gas elution tower; 300-air port. DETAILED DESCRIPTION

[0020] The present invention can be better understood according to the following embodiments.

[0021] The structures, proportions, sizes, etc. illustrated in the drawings of the specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the utility model, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effect and purpose that can be achieved by the utility model, should still fall within the scope of the technical content disclosed by the utility model. At the same time, the terms such as "upper", "lower", "front", "back", "middle" and so on quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the utility model. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the utility model without substantial change of the technical content.

[0022] Combination Figure 1 As shown, the utility model centrifugal pump machine seal blocking liquid recycling system includes a normal pressure tank 10, a blocking liquid circulation pump 20 and a machine seal flushing water pipeline 30; the water outlet of the normal pressure tank 10 is connected to the blocking liquid circulation pump 20 through a pipeline; the blocking liquid circulation pump 20 is connected to the flushing pipeline 101 of each alkali liquid circulation pump 100 through the machine seal flushing water pipeline 30; the flushing pipeline of each alkali liquid circulation pump 100 is connected to the normal pressure tank 10 through the flushing water return pipe 40. The flushing return water of each alkali liquid circulation pump 100 is recovered through the normal pressure tank 10, and then recycled as machine seal flushing water.

[0023] The mechanical seal flushing water pipeline 30 includes a main pipe and branch pipes connected to the flushing pipelines 101 of each alkali solution circulation pump 100 .

[0024] In some embodiments, a flushing pipeline is also provided on the sealing liquid circulation pump 20, the water inlet of the flushing pipeline is connected to the mechanical seal flushing water pipeline 30, and the water outlet is connected to the atmospheric pressure tank 10 through the sealing liquid circulation pump flushing return pipe 50, thereby simultaneously recovering the mechanical seal flushing water of the sealing liquid circulation pump.

[0025] In some embodiments, the flushing water return pipe 40 and the blocking liquid circulation pump flushing return pipe 50 are combined into a main pipe and then connected to the atmospheric pressure tank 10 together.

[0026] In some embodiments, the water outlet of the blocking liquid circulation pump 20 is also directly connected to the atmospheric pressure tank 10 through a minimum continuous flow pipeline 60 to prevent the blocking liquid circulation pump from being blocked when it is first started.

[0027] In some embodiments, the mechanical seal flushing water pipeline 30 and the minimum continuous flow pipeline 60 are connected in parallel at the water outlet of the sealing liquid circulation pump 20 .

[0028] In some embodiments, a check valve 70 is further provided at the water outlet of the blocking liquid circulation pump 20 .

[0029] In some embodiments, the atmospheric pressure tank 10 is further connected to a leaching pipeline 90 of the silane gas leaching tower 200 via a water replenishment pipeline 80 , and the washing water on the leaching pipeline 90 is used as the replenishment water of the atmospheric pressure tank 10 .

[0030] In some embodiments, a float switch is also provided in the atmospheric pressure tank 10 to achieve automatic liquid replenishment.

[0031] In some embodiments, on the flushing pipeline 101 of each alkali solution circulation pump 100 , an inlet hand valve 102 is provided at the front end of the alkali solution circulation pump 100 , and a recovery hand valve 103 is provided at the rear end of the alkali solution circulation pump 100 .

[0032] When in use, the tail gas containing trace amounts of silane produced in the original process production enters the silane gas elution tower 200. The bottom of the silane gas elution tower is a 5% NaOH aqueous solution which is pressurized to 0.8 MPa by the alkali liquid circulation pump 100 and sprayed to the top of the tower to absorb the silane gas. The mechanical seal flushing plan of the alkali liquid circulation pump 100 is Plan 54, and the sealing liquid is directly discharged to the ditch through the air port 300.

[0033] In order to prevent a large amount of sealing liquid from being wasted, the sealing liquid is now recycled. A normal pressure tank 10 and a sealing liquid circulation pump 20 are set on site to ensure the stable circulation of the sealing liquid system. A minimum continuous flow pipeline 60 is set to prevent the sealing liquid circulation pump 20 from being blocked when the pump is just started. When the outlet pressure of the sealing liquid circulation pump 20 reaches 0.3-0.4Mpa during operation, open the sealing liquid inlet manual valve 102 of each machine seal on site, adjust the sealing liquid outlet pressure to about 0.3Mpa, and slowly open the sealing liquid recovery manual valve 103 to allow the sealing liquid to return to the normal pressure tank 10, forming an independent self-circulating system.

[0034] The utility model provides a centrifugal pump machine sealing liquid recycling system and a method. There are many methods and ways to implement the technical solution. The above is only the preferred implementation of the utility model. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the utility model, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the utility model. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A centrifugal pump sealing liquid recycling system, characterized in that: The invention comprises a normal pressure tank (10), a sealing liquid circulation pump (20) and a mechanical seal flushing water pipeline (30); the water outlet of the normal pressure tank (10) is connected to the sealing liquid circulation pump (20) through a pipeline; the sealing liquid circulation pump (20) is connected to the flushing pipeline (101) of each alkali liquid circulation pump (100) through the mechanical seal flushing water pipeline (30); and the flushing pipeline of each alkali liquid circulation pump (100) is connected to the normal pressure tank (10) through a flushing water return pipe (40).

2. The centrifugal pump sealing liquid recycling system according to claim 1, characterized in that: The mechanical seal flushing water pipeline (30) comprises a main pipe and branch pipes connected to the flushing pipelines (101) of each alkali solution circulation pump (100).

3. The centrifugal pump sealing liquid recycling system according to claim 1, characterized in that: The sealing liquid circulation pump (20) is also provided with a flushing pipeline, the water inlet of the flushing pipeline is connected to the mechanical seal flushing water pipeline (30), and the water outlet is connected to the atmospheric pressure tank (10) through the sealing liquid circulation pump flushing return pipe (50).

4. The centrifugal pump sealing liquid recycling system according to claim 3, characterized in that: The flushing water return pipe (40) and the blocking liquid circulation pump flushing return pipe (50) are combined into a main pipe and connected together to the atmospheric pressure tank (10).

5. The centrifugal pump sealing liquid recycling system according to claim 1, characterized in that: The water outlet of the blocking liquid circulation pump (20) is also directly connected to the atmospheric pressure tank (10) via a minimum continuous flow pipeline (60).

6. The centrifugal pump sealing liquid recycling system according to claim 5, characterized in that: The mechanical seal flushing water pipeline (30) and the minimum continuous flow pipeline (60) are connected in parallel at the water outlet of the sealing liquid circulation pump (20).

7. The centrifugal pump sealing liquid recycling system according to claim 6, characterized in that: A check valve (70) is also provided at the water outlet of the blocking liquid circulation pump (20).

8. The centrifugal pump sealing liquid recycling system according to claim 1, characterized in that: The atmospheric pressure tank (10) is also connected to the leaching pipeline (90) of the silane gas leaching tower (200) via a water supply pipeline (80).

9. The centrifugal pump sealing liquid recycling system according to claim 8, characterized in that: A float switch is also provided in the atmospheric pressure tank (10).

10. The centrifugal pump sealing liquid recycling system according to claim 2, characterized in that: On the flushing pipeline (101) of each alkali solution circulation pump (100), an inlet hand valve (102) is provided at the front end of the alkali solution circulation pump (100), and a recovery hand valve (103) is provided at the rear end of the alkali solution circulation pump (100).

Images