Centrifugal pump with dry gas seal classification and advantages and disadvantages

Centrifugal pump transport medium is liquid. According to different working conditions, the following types of seals can be used: 1, double-sided dry gas seal Double dry gas seal can be used in the vast majority of centrifugal pump shaft seal, it has the following characteristics: 1) "Instead of the traditional" liquid obstruction "principle, that is, using pressurized sealing gas instead of pressurized sealing liquid to ensure that the process medium to achieve" zero escape "; 2) complete sealing non-contact operation, the power consumption is only traditional double- 5%, the service life of more than 5 times longer than the traditional seal; 3) A simple structure of the auxiliary system to ensure that the process media is not contaminated and the process medium does not leak to the atmosphere, completely out of the traditional double-sided mechanical seal on the oil system. Sealed gas using industrial nitrogen or industrial instrumentation, the pressure is higher than the medium 0.15-0.2MPa. Pumps with double-sided dry gas seal of the deficiencies are: 1) need a certain pressure of the gas source, gas pressure at least higher than the medium pressure 0.2MPa; 2) a trace of gas into the process. 2, series dry gas seal pump series dry gas seal has the following characteristics: 1) dry gas seal and contact type mechanical seal used in tandem, the mechanical seal is the main seal, dry gas seal is the secondary seal; 2) dry gas seal and The main seal between the access to nitrogen, to ensure that the main seal has a certain back pressure, greatly extending the service life of the main seal; 3) The main seal leakage of process gas discharged into the torch with sealed gas to ensure that the process medium does not leak to the atmosphere, is a Environmental protection; 4) After the failure of the main seal, dry gas seal play a major role within a short time to prevent a large number of process media to the atmosphere leak. 5) The life of this type of seal depends on the service life of the mechanical seal, which is usually about 2-3 years. 6) The seal is mainly used for volatile media occasions, such as liquid hydrocarbon media; less demanding on the seal gas pressure. The inadequacies of this seal are: 1) The seal is not yet a completely dry-gas seal, with the overall performance being between the mechanical seal and the dry seal. 2) The seal is suitable for volatile media occasions, the use of a narrow range. Source: China Sealing Network Forum