The Analysis of BW-150Slurry Pump Displacement Unevenness and Key Parts Life
|Central South University
|slurry pump displacement unevenness structure optimization finite element analysis life-span
Abstract:In the modern drill engineering, the slurry pump is always to be the object which people pay attention to. It’s used to be called’the heart of drilling machine’. But the components, such as pump valve, piston and cylinder sleeve are easily damaged because of the bad work condition, resulting high repairment costs, which are urgent to be solved. In this article, the author studies the BW-150slurry pump used by Tongling Nonferrous Metals Corporation. In order to decrease the displacement fluctuation and improve the life-span of easily wear parts, the key parts motion analyses of BW-150slurry pump and structure optimization are discussed in details. The main contents are showed as follows:(1) According to the measurement of the BW-150slurry pump, the models of driving parts, hydraulic head parts and general assembly drawing are established, which provides a reference model for the new pump design. The author theoretically analyzes the slurry pump and establishes the crank and connecting rod mechanism’s motion equation, characteristic analysis of piston equation, deducing the pump’s transient discharge equation and average discharge equation. The reasons for discharge fluctuation and pressure fluctuation are found by analyzing the BW-150slurry pump’s structure size and technical parameters, in order to establish pump emulations of mechanical motion and power energy then validate the correctness of the results. In order to decrease pump discharge fluctuation and pressure fluctuation, to increase pump service life, the author improved the traditional design method of air camber and calculated slurry pump classified calculation air chamber gasbag volume in different λ, then determine the BW-150slurry pump gasbag volume.(2) Piston’s working principle, life influencing factors and failure forms are discussed. According to analyze piston’s force status in static load and dynamic load, Simulate rubber cup of displacements and stress changes in different working condition by finite element analysis of rubber cup, mechanical characteristics of rubber cup can be get by the load. Finally, Piston’s structure can be improved and slurry pump’s service life can be increased more, which can reach to32.88hours, comparing to13.56hours before.(3) After building the ball valve’s motion equation and analyzing pump valve’s working principle and failure form, the improvement measures for pump valve can be received. Under the maximum working pressure (7MPa), the stress distributions of the pump valve are studied by using the finite element analysis. The results show that the maximum strain is around the holes of the valve, which is about0.37×10-5. The strength meets the requirement and the thickness can be deceased to some degree.