Mechanical seal

Abstract

Provided is a mechanical seal for which a flushing pie and a cooler are not necessary. The mechanical seal is an outside mechanical seal which seals a fluid to be sealed that tends to leak from the inner periphery toward the outer periphery of a slide surface. The mechanical seal is characterized in that a rotatable seal element and a stationary seal element are provided on the outside of a stuffing box, the stationary seal element which contains a spring is attached to a seal cover secured to a housing, the rotatable seal element is attached to a collar directly attached to a rotary shaft, a rotary system comprised of the rotatable seal element and the collar is disposed so as to rotate in the external side atmosphere, the balance ratio (A2 / A1) is set so as to be not more than 1 if a projected area in the axial direction of the slide surface of the stationary seal element is represented by (A1), and a projected area in the axial direction, which receives a seal fluid pressure that acts as a moving force to move the stationary seal element in the axial direction is represented by (A2), and a ring-shaped cooling jacket is provided between the inner periphery of the housing and the outer periphery of the rotary shaft.

Description

technical field [0001] The present invention relates to a shaft seal device in which the liquid to be sealed is high temperature, which is used in a hot water pump such as a boiler feed water pump or a condensate pump in a thermal power plant, or a hot oil pump. Background technique [0002] As a shaft seal device used in hot water pumps such as boiler feed water pumps or condensate pumps in thermal power plants, thermal oil pumps, etc., conventionally, for example, image 3 Shaft seal unit shown. [0003] image 3 The shaft seal device shown based on the prior art has a built-in form (a form for sealing fluid that leaks from the outer periphery to the inner periphery of the sliding surface) as a contact mechanical seal, and the rotating side seal element 52 and The stationary-side seal element 55 is slid in close contact with the opposite end faces of the stationary-side seal element 55 by a spring 56 biasing the stationary-side seal element 55 in the axial direction, and t...

AI Technical Summary

Problems solved by technology

[0007] (2) A suction ring is required, which increases the installation space and power consumption

[0010] (5) In order to cool the mechanical seal, sometimes the air side of the sliding part S ( image 3 In the case of the inside of the sliding part S), water is supplied to perform quenching, but due to high temperature, the quenching water evaporates, bleaching powder in the water is precipitated, and the mechanical seal is fixed and leaks.

[0012] However, conventional technology 2 also has the following problems: in order to cool the mechanical seal, it is necessary to flush the piping, the cooler, and a large amount of cooling water for the cooler.

Images