Petrochemical industry pump shaft seal is roughly divided into contact seal, non-contact seal two categories. Contact seals include packing seals and mechanical seals; non-contact seals with labyrinth seals, spiral seals and vice impeller seals. 80 ~ 90% of petrochemical industry chemical pump using mechanical seal. The use of mechanical seals is an effective way to solve the problems of running, running, dripping, leaking, improving environmental protection, improving working efficiency and reducing production cost. It is one of the indispensable means to realize industrial modernization.
Research drip
Guangzhou Haotian Chemical Company ZW600-80-type forced circulation pump, flow 2650m3 / h, pump slurry containing 8% to 10% (wt) or even higher salt crystals, the transfer fluid temperature up to 120 ℃. The shaft seal structure comprises a shaft sleeve, a front machine cover, a seal ring, a pump cover, a back machine cover, a water seal cover and two sets of the two sets installed between them in tandem and independent from each other Mechanical seal, mechanical seal 1 Balanced external static compensation ring machine seal, mechanical seal 2 with double-end fork fork machine seal.
Kaiping Guangdong Polyester Enterprise Group slurry pump is Roots pump, slurry medium density l350m3 / kg, the outlet pressure 600kPa, motor speed 1500r / min. The seal of the slurry is in the form of a mechanical seal; the EG is used for flushing, and the seal is sealed with a skeleton oil seal to prevent the flushing fluid from leaking. The improvement measures include: changing the seal position of the O ring at both ends of the push ring and adopting the fluorine rubber O ring; using the PTEF material to make a oil seal similar to the frame oil seal, which is installed between the fixing ring fixing seat and the pump body to prevent the pulp Into the moving material, static ring sealing surface.
Japan's Mitsubishi Heavy Industries 93A reactor cooling pump (RCP) shaft seal system includes three seals. The first seal (primary seal) is a film-riding end seal that controls leaks and uses a non-contact controlled leak system to provide less deviation over long periods of operation (about 1 year). The role of the No. 1 seal is to reduce the pressure of the coolant from 15 MPa to 0.3 MPa, including the rotary side seal runner and the stationary side seal ring.
United States Joseph L
Foszcz wrote an overview of the shaft seal, said the mechanical seal can handle a variety of fluids, the pressure up to 13.8MPa, speed up to 50000rpm, the temperature from -254 ~ 649 ℃, the pump is not allowed to leak more and more popular applications. The article gives a typical mechanical seal assembly, including a seal, a seal ring, stationary seal ring, O-ring (2 seal) and so on.
Part of the patent introduction
The utility model patent ZL99236406 of Guangzhou Pump Factory discloses a combined sealed leak-free pump which comprises a rotating main shaft, an impeller, a pump cover and a machine cover, and is arranged between the rotating main shaft, the impeller, the pump cover and the machine cover Parallel set of two sets of mechanical seals, the outer seal is close to the pump cover single-end balance static compensator (first stage seal), the inner seal is close to the rotating spindle double-end machine seal (second stage Sealed), the pump installed in the pump by the combination of mechanical seal, the transmission medium and the separation medium separated from the medium to prevent the transmission medium through the rotating shaft to the outer space leakage.
Japan NIPPON PILLAR PACKING CO
U.S. Patent No. 5,501,470 to LTD discloses a non-contact shaft seal for rotary machines that creates a fluid film seal on the high pressure side of the shaft seal face. A plurality of pressure grooves are arranged in radial or peripheral direction on the rotating sealing surface to generate dynamic pressure in the fluid film.
JP 198219297 filed by Mitsubishi Heavy Industries of Japan discloses a shaft seal suitable for a high-pressure rotary machine in which a high-pressure chamber and a low-pressure chamber are hermetically sealed with a plurality of grooves on the rotating ring so as to rotate the fluid along the rotation shaft Peripheral delivery.
Japan NIPPON PILLAR PACKING CO
JP Patent Application JP2003185030 filed by LTD discloses that the shaft sealing device adopts the second machine seal for high-pressure equipment. The first machine seal is inserted into the rotary seal ring by the two-stage sealing member so that the second sleeve can move relatively in the axial direction so that the first stationary side retainer can keep the first stationary seal ring inserted in the first sleeve. This structure can reduce the size and weight.