High pressure washdown system with multiple sets of mechanical seals

Abstract

A high pressure resistant flushing system with multiple mechanical seals comprises a centrifugal pump formed by a pump housing (7), an impeller (6) and a pump shaft (1). One end of the pump shaft (1) connects to the impeller (6), and the other end extends out of the pump housing (7) through a high pressure end mechanical seal (4) disposed at a shaft hole of the pump housing (7). An external portion of a bushing (2), located between the pump housing (7) and a bearing (11), is provided with first to N th buffer chambers (121, 122, …, 12N) formed by connecting first to N th gland seals (31, 32, …, 3N) end to end in a sealed manner. A shaft hole at a high-pressure side of each gland seal is provided with a mechanical seal (5) connected to the bushing (2) in a sealed manner. A liquid inlet of each gland seal is correspondingly connected, by a liquid inlet line (14), to a liquid outlet of an accumulator (15) filled with a buffering liquid. A liquid outlet of each gland seal is correspondingly connected, by a liquid outlet line (13), to a liquid inlet of the accumulator (15). The bottom of the gland seal (31) of the pump housing (7) is connected to the pump housing (7) in a sealed manner. High temperature resistance of the centrifugal pump of the high pressure resistant flushing system is thus improved.

Description

technical field [0001] The invention relates to a shaft seal flushing system of a centrifugal pump. In particular, it relates to a high-pressure flushing system with multiple sets of mechanical seals that are connected in series to form a step-by-step pressure decrease with multiple sets of mechanical seals. Background technique [0002] In appendix D of the API682 standard for shaft seal systems of centrifugal pumps and rotor pumps, the pressure of the internal circulating fluid of the standard seal 52, 53 flushing scheme system is different, such as figure 1 and figure 2 Shown is the prior art of 52 flushing schemes, the liquid between two sets of mechanical seals facing back is non-pressurized and circulating buffer. in, [0003] figure 1 and figure 2 It is a prior art 2CW-CW container double-contact wet seal with buffer, and a schematic diagram of a buffer flushing system without pressure (connected to the atmosphere) and capable of circulating flow ( figure 1 ) ...

AI Technical Summary

Problems solved by technology

[0017] The above-mentioned problems have always restricted the centrifugal pump from being able to withstand high pressure, because in the prior art, the mechanical seal is the weakest link of all components in the centrifugal pump. If the pressure bearing capacity of the mechanical seal is not improved, no matter how thick the pump casing is made, No matter how high the strength of other parts is, it will not help. Once the material pressure in the centrifugal pump exceeds the pressure bearing capacity of a single set of mechanical seals, the centrifugal pump will leak immediately. If the centrifugal pump leaks, it will not work normally, or even stop production.

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