In the 90s of last century, Lanzhou petrochemical company undertook a major national equipment and technology research project--"the research and development technology of the dilute sulphuric acid pump", this subject contains the research and development of shaft seal for corrosion-resistant dilute sulfuric acid pump. This subject requires the development of fine solid particles which have a simple structure and can be used in conveying medium. The medium pressure < 0. 5MPa, the temperature is during 20 to 150℃, the dilute sulfuric acid pump with the service life of 8000 hours is sealed with mechanical seal to meet the special requirements of the chemical process for the dilute sulphuric acid pump. After many years of experimental research and industrial assessment of users, this sealing and dilute sulfuric acid pump passed the technical appraisal organized by China National Petroleum Corporation.
The structural design. After many experiments, the mechanical seal
structure of rubber bellows was finally determined to be static or internal balance structure. As the only elastic element of this seal, the rubber bellows adopt the single corrugated large waveform structure. With the static ring assembly component, the guide shall be set as two convex platforms, and the fitting part of the sealing chamber shall be set as the shoulder of the installation positioning platform. The front cover of the sealing gland is extended to ensure that the rubber bellows have good strength and floatability, so as to absorb the vibration of the pump shaft and automatically find alignment, and ensure that the static ring can move axially to compensate for the wear of the end surface, so that the end face is always in good seal state.