Closed mechanical-seal pump ring and shaft-seal flushing system with same

Abstract

Disclosed are a closed mechanical-seal pump ring and a shaft-seal flushing system with the same. The pump ring is provided with an annular left pump ring side plate and an annular right pump ring side plate which are parallel to each other, inner circumferences of the left pump ring side plate and the right pump ring side plate sleeve the outer circumferential surface of a shaft sleeve of a centrifugal pump, the outer circumferential edges of the left pump ring side plate and the right pump ring side plate are connected with a sealing gland of the centrifugal pump at an interval, a plurality of blades in rotatable and radial arrangement are arranged between the left pump ring side plate and the right pump ring side plate and are perpendicular to the left pump ring side plate and the right pump ring side plate, an end opening formed by closing ends of the radial blades corresponds to a liquid outlet of the shaft sleeve, and an end opening formed by edges of radial ends of the radial blades corresponds to a liquid inlet of a liquid outlet passage formed on the sealing gland. The closed mechanical-seal pump ring has the advantages that liquid accelerating distance is increased, and idle work is reduced; most liquid in a seal cavity can be enabled to flow, and a fluid flowing path can be lengthened to widen the flow area.

Description

technical field [0001] The invention relates to a shaft seal flushing system of a centrifugal pump. In particular, it relates to a closed mechanical seal pump effect ring and a shaft seal flushing system with the pump effect ring. Background technique [0002] In the API682 standard appendix D of the centrifugal pump and rotor pump shaft seal system, the standard seal flushing plan 52, 53A, 53B, 53C internal liquid circulation power is provided by the pump effect ring, such as figure 1 Shown prior art. figure 1 , figure 2 , image 3 Schematic diagram showing the flushing system and internal structure of the prior art 2CW-CW cartridge double-contact wet seal with buffer fluid and 3CW-FB cartridge double-contact wet seal with barrier fluid facing back configuration. Figure 4 A schematic diagram showing the flushing system and internal structure of the prior art 3CW-BB with the back-to-back configuration of the cartridge double-contact wet seal (1.2 in API682). After the...

AI Technical Summary

Problems solved by technology

[0006] 3. Due to the short distance that the fluid passes in the sealing cavity, that is to say, the path is short, only a small part of the liquid in the part where the fluid passes participates in the flow, and most of the liquid is always in a static state. The two sets of mechanical seal friction pairs are the most needed. Cooling place, but the nearby cooling liquid is always in a relatively static state, which is quite unfavorable for mechanical seals

[0008] 5. In order to produce an effective head, reduce backflow and improve driving efficiency, the maximum outer diameter of the rotating pump effect ring should be as close as possible to the inner wall of the stationary cavity. As a result, the part of the liquid between the moving part and the stationary part Under a great shearing force, it not only consumes power, generates excess heat, but even destroys the molecular structure of the liquid and affects the physical and chemical stability of the liquid.

[0009] 6. Due to the small gap between the inner walls of the stationary cavity of the rotating pump effect ring, interference often occurs and the mechanical seal fails

[0014] 11. It is impossible to effectively adjust the flow rate and pressure difference of the circulating fluid by changing the geometric parameters of the pump effect ring

Therefore, the thermal balance cannot be actively adjusted.

[0015] 12. It is difficult to achieve the effect of the pump with low speed (n<1000rad / min)

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