For corrosion-resistant and wear-resistant centrifugal pumps, due to the particularity of the conveying medium-both abrasive and corrosive, there are some special requirements for the pump shaft seal mechanical seal, which can be summarized as follows:
1. Corrosion-resistant and wear-resistant centrifugal pump shaft seals must be dry mechanical seals
The dry seal mentioned here refers to the "generalized dry" that users often say, that is, the frictional heat of the sealing surface is washed and cooled without the pumping medium, and the external liquid such as cooling water, buffer, etc. cannot leak into the pumping Go in the medium.
2. Using a pair of hard-to-hard material friction pairs
Because the pumped medium contains a large amount of solid powder, this pair of friction pairs must be made of wear-resistant materials with high hardness to increase the service life of this pair of friction pairs.
3. The spring of the mechanical seal is not in contact with the pumped medium
The pumping medium contains a large amount of solid powder. In order to prevent the powder from affecting the expansion and contraction of the spring after the powder deposits, the mechanical seal spring does not contact the pumping medium.
4. Open sealed cavity
For a conventional mechanical seal with a self-flushing fluid system, the sealing cavity is equipped with a throttle bushing to reduce volume loss; and for the sealing cavity of a corrosion-resistant and wear-resistant centrifugal pump, an open type should be used to prevent solid powder The sealing surface of the friction pair is located in the open sealed cavity.
