Optimal Design Of The Drum Opening In A Two-stage Piston Pusher Centrifuge

To solve the problem that oversized resistance of sieve to filtrate and seriouswear of drum opening wall of centrifuge, taking the first stage sieve and the first stagedrum of P-85type two-stage piston pusher centrifuge as the research object, and todesign and optimize the drum opening structure. The results provide a series ofreferences to optimize the structure design and industrial application of the two-stagepiston pusher centrifuge.The FLUENT software is used to build the three-dimensional model andsimulate the fluid flow of sieve and drum opening, the small experiment equipmentwas used to get the direction angle of material in0degrees declined drum openingand15degrees declined drum opening at different rotational speed, and compare theexperiment value and simulation value, which verified the correctness of thenumerical simulation method. On this basic, to simulate the motion trajectory of fluidin sieve, explore that the influence of sieve angle to reduce the resistance of sieve tofiltrate, getting the best angle of sieve angle. Result shows that the inclined sieve wasan effective method to reduce the flow resistance. With the increase of rotationalspeed, more and more filtrate and entrained particles concentrated on the left side wallof sieve throw away from the outlet, and hence the best inclined sieve changes withrotational speed. At speed of1000~1100r/min,7degrees inclined sieve is the best forreduce the flow resistance. At speed of1200~1300r/min,8degrees inclined sieve isthe best for reduce the flow resistance. The second stage sieve of centrifuge was usedto be studied, result shows that the optimal result of the first stage sieve and thesecond stage sieve at different rotational speed is identical. Therefore, choosing thesame sieve structure when model selection of the first sieve and the second sieve.To solve the problem that serious wear of drum opening wall of centrifuge,FLUENT software was used to simulate the three-dimensional flow field of the firststage sieve and the first stage drum, exploring the optimal inclined angle of drumopening at different rotational speed. Result shows that the inclined drum opening wasan effective method to reduce the wear of drum opening wall. At speed of1000~1100r/min,15degrees inclined drum opening was optimal. At speed of1200~1300 r/min,20degrees inclined drum opening was optimal. Meanwhile, the experimentresult shows that the15degrees inclined drum opening is better than0degreesinclined drum opening.The drum opening performance of centrifugal radius and opening shape andsieve angle was used to research. Result shows that the relative deposition volumefraction and impact angle and particle speed influence on the wear of drum opening,the change of opening shape was not generated the obvious effect to reduce the wearat drum opening wall, on the contrary, it may be weaken the strength of drum, thesieve angle was not effect to the wear at drum opening wall.The research results provided a series of references to optimize the structuredesign of sieve and drum opening.