The medium of high temperature heavy Fixed Vane Pumps has the following common characteristics:
1. High temperature: generally 340～400℃;
2. The medium viscosity is large: the general kinematic viscosity at temperature is (12～180)×10-6m/s;
3. The medium has particles: such as catalyst, coke, sand and other impurities.
4. For high temperature heavy oil medium vane pump with mechanical seal. Now all companies use welded metal bellows mechanical seals. DBM type, XL-604/606/609 type, YH-604/606/609 type and so on are in better use now. The bellows material adopts stainless steel such as AM350, INCONEL718, Hastelloy B, C; corrosion-resistant high-temperature alloys, etc., and some wave plates adopt double-layer structure to increase the bearing pressure from 2MPa to 5MPa, which effectively solves the loss of the bellows. Bullet problem.
5. In view of the coking and coking on the inside of the corrugated pipe and the solid particles, the relevant materials for the solution have been explained, such as the use of steam purging, the use of « hard to hard » friction pairs, the use of external flushing, etc. To a certain extent played a better role. However, the various methods proposed before are not ideal in practical applications due to various factors. In order to better improve the service life of the mechanical seal, save capital and reduce consumption, for various situations, it is recommended that the following measures should be combined and adopted. The metal bellows should be designed as a rotating structure. The rotating bellows mechanical seal has self-cleaning Centrifugal action, which can reduce deposits on the outer periphery and coking on the inner side of the Vane Pumps.