Application of double end gas film mechanical seal (2)-

Application of double end gas film mechanical seal (2)

　2018-11-08　　

Application of double end face gas film mechanical seal (2):

When the double end face gas film mechanical seal is in operation, the seal end faces are not in contact, so there is no wear problem. In this seal, using gas instead of liquid as the blocking fluid has considerable advantages: for example, inert gas like nitrogen has better compatibility with the sealed medium than the buffer liquid, and the buffer liquid may contaminate the sealed medium and reduce Its quality; buffer gas will not solidify or crystallize like liquid in some cases. When the blocked gas (when not allowed) enters the sealed medium, appropriate gas separation measures should be taken, such as designing a gas separation gas supply system. 261 Mechanical seal

The double-end gas film seal has very high operational stability. As long as the blocking gas acts on the sealed end face with a higher pressure, zero leakage of the sealed medium can be achieved.

In the liquid medium, when the gas film seal blocks the gas supply system and fails, the gas film mechanical seal is replaced by a wet running mechanical seal to continue working. The seal on the medium side is closed due to the double pressure balance. The check valve in the blocked gas supply system can prevent the sealed medium from returning, and the sealed medium can lubricate and cool the sealing end face of the side seal. In the case of wet-running mechanical seals, a small amount of the sealed medium may leak into the sealed cavity. The seal on the atmosphere side always operates in a gas film seal mode before the sealed medium is filled with the sealed cavity. In order to ensure the unblocked gas supply, a contact switch that monitors the pressure change in the sealed cavity can be installed in the gas supply system. Once the pressure in the cavity changes suddenly, the contact switch will trigger the alarm.

The working parameters of the double-end gas film seal: the sliding speed is about 25m/s, the working temperature is about -20~280℃ (mainly determined by the material of the auxiliary seal), and the working pressure is about 2.5MPa.　　973.html,

Application of double end gas film mechanical seal (1) 　　 application example of double end gas film mechanical seal