Experimental study on friction and wear characteristics of disc-sealed screw pump meshing pairs in sand-contaminated crude oil

Abstract

The disc-sealed screw pump is commonly used for pumping marine oil spills and refinery oily sludge containing large particulate impurities such as sediment. The wear resistance of its meshing pair during operation is the key factor affecting reliability. However, experimental studies on the friction and wear of the meshing pair in disc-sealed screw pumps under sand-contaminated conditions remain scarce, significantly hindering the technology's performance optimization and large-scale application. To address this, a novel test platform was developed to evaluate the friction and wear performance of the screw-sealing disc pair under complex media, based on actual working and meshing parameters. Through simulated tests, the wear volume and friction coefficient of the polyurethane sealing disc material were systematically analyzed under sand-contaminated crude oil, with emphasis on their quantitative relationships with normal load and sliding velocity. A comparative study on polyurethane wear in sand-contaminated versus sand-removed crude oil revealed that under sand contamination, wear volume increased with load and sliding velocity, while the friction coefficient decreased. Higher hardness reduced both wear and friction. Wear volume peaked at a critical sand concentration. Compared with the sand-removed crude oil medium, the wear loss and frictional coefficient of polyurethane in the sand-contaminated crude oil medium increased significantly, both with an increase rate of more than 50%.