There are three reasons for the sudden leakage of the three-screw pump during normal operation. One is the leakage of the mechanical seal, the other is the misalignment of the installation, and the third is the wear of the shaft sleeve.
The three-screw pump has a variety of structural forms, the general small flow rate is 0.2~6.5m3/h, the pump body and the bushing of the pump are integrated (collectively referred to as the pump body), and the shaft seal is a mechanical seal. The liquid to be transported moves axially in a straight line at a constant speed in the pump, so the pressure pulsation is small, the flow rate is stable, and the noise is low. Due to the small inertia of the rotating parts, the starting moment and vibration are very small.
The main reasons for the analysis are as follows:
1. Evacuation, cavitation or pressure holding for a long time, resulting in damage to the seal;
2. The actual output of the pump is relatively small, and a large amount of medium circulates in the pump, and the heat accumulates, causing the medium to vaporize, resulting in seal failure;
3. The return flow rate is too large, causing the bottom of the container (tower, kettle, tank, pool) on the side of the suction pipe to have sediment floating and damage the seal;
4. For a long period of outage, there is no manual cranking when restarting, and the friction pair will tear the sealing surface due to adhesion;
5. Corrosive, polymeric and gelling substances in the medium increase;
6. Rapid changes in ambient temperature;
7. Frequent changes or adjustments in working conditions;
8. Sudden power failure or shutdown due to failure. The three-screw pump leaks suddenly during normal operation. If it cannot be found in time, it will often lead to major accidents or losses. It must be paid attention to and effective measures should be taken.