Multistage centrifugal high pressure liquefied hydrocarbon pump

Abstract

The invention relates to a multistage centrifugal high pressure liquefied hydrocarbon pump. The multistage centrifugal high pressure liquefied hydrocarbon pump comprises an axial force balance mechanism, a mechanical seal self-flushing mechanism and a rotating shaft, wherein a liquid return hole is formed in a first-stage middle section of the pump, a second-stage middle section sealing rubber ring is arranged between a second-stage middle section of the pump and an outer barrel, and a suction box body sealing rubber ring is arranged among a suction box body, the outer barrel and the first-stage middle section; one end of a balance liquid return pipe assembly is connected with a balance chamber, and the other end of the balance liquid return pipe assembly is connected with a second-stage impeller suction chamber by virtue of the outer barrel; one end of a forward flushing pipe assembly is connected with an outlet of a first-stage impeller, the other end of the forward flushing pipe assembly is connected with a driving side mechanical seal assembly, one end of a backward flushing pipe assembly is connected with a suction chamber, and the other end of the backward flushing pipe assembly is connected with a non-driving side mechanical seal assembly. The multistage centrifugal high pressure liquefied hydrocarbon pump also comprises an automatic control reflux type thermal control mechanism. The multistage centrifugal high pressure liquefied hydrocarbon pump has the advantages that vaporization of pumping medium can be prevented, cooling and lubricating properties of a mechanical seal end face are improved, quantity of minimum continuous thermal limited flows can be reduced, energy consumption can be reduced, and safe and reliable operation of the pump is guaranteed.

Description

technical field [0001] The invention relates to the field of pump valves, in particular to a multistage centrifugal high-pressure liquefied hydrocarbon pump, including an axial force balance mechanism, a mechanical seal self-flushing mechanism and the like. Background technique [0002] The liquefied hydrocarbon pump belongs to the light hydrocarbon pump, and it transports dangerous media that are flammable, explosive, easy to vaporize and volatile, low density, low ignition point, and high saturated vapor pressure, and the change of temperature is extremely sensitive to its vaporization pressure. For example, low-carbon liquid ethylene, butane and propylene. Liquefied hydrocarbon pumps, especially high-pressure liquefied hydrocarbon pumps, are the most critical dynamic equipment in the processes of petrochemical industry and petroleum refining plants. [0003] At present, vertical high-speed pumps (tangential pumps) or reciprocating plunger pumps are generally used for low...

AI Technical Summary

Problems solved by technology

Such a flushing scheme, if the pump vaporizes, will affect the stability of the self-flushing pressure of the mechanical seal, which may lead to a series of operational failures such as mechanical seal damage and leakage.

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