Failure and solution of vertical sand pump
Release time: 2015/10/28 Ai Yi NewsViews : 1455
The vertical sand pump submerged the pump casing directly into the drilling fluid, completely solving the problem of sealing and leakage of the horizontal sand pump. However, because the length of the shaft of the vertical sand pump is greatly increased, in order to ensure the stability of the impeller operation, a centering sleeve must be installed near the impeller. The working environment of the centering sleeve is located in the sand-containing drilling fluid, and its abrasion resistance becomes vertical. The key to the reliable operation of the sand pump is that in most cases, the cause of the wear of the centering sleeve is because the centering sleeve is too invaded with the sandy drilling fluid. The high-speed rotating centering ring fixing ring and moving ring are repeatedly ground in the sandy medium. The fixed ring and the moving ring wear quickly. At the same time, since the vertical sand pump casing and the centering sleeve are not in the drilling fluid, the slight vibration generated after the centering sleeve is worn is not easy to be detected, causing the centering to be more severely worn, until Wear failure. Vertical sand pumps have the same causes as horizontal failures. The main reason is that sandy drilling fluid enters the bearing cavity along the pump shaft or the inner wall of the casing, causing the bearing to fail.
So, how to improve the life of the sand pump? At present, the horizontal sand pump with a combined seal is the sand pump with the widest application and the longest life. When the sand pump is running, there is negative pressure in the combined sealing cavity, and the sealing device is in an idle state, but unnecessary wear occurs. Only when the pump is stopped, the negative pressure in the sealed cavity disappears, and the sealing device plays the role of sealing the drilling fluid. According to this situation, a parking seal is designed to separate the dynamic and static rings of the combined seal when the sand pump is running or reduce the contact force to avoid wear of the dynamic and static rings. When the pump is stopped, the dynamic and static rings are enlarged under the action of the parking seal. The contact force better seals the drilling fluid. In this way, not only the wear of the combined seal is reduced, but also the sealing effect is enhanced, and the reliability of the sand pump is greatly improved.