Development And Experimental Research On A Forced Discharged Self-cleaning Centrifuge

Drilling fluid plays an important role of the oil drilling industry. It can cool the drill bit, flush the bottom hole and keep the balance of bottom pressure. The drilling fluid contains many abandoned drilling cuttings which are returned back from the down hole. The drilling crew must deal with the drilling cuttings before discharge these because if discharge the drilling cuttings without processing, the drilling fluid that contains heavy metal components would pollute the environment. Foreign drilling crew generally uses centrifuges to separate the drilling fluid on the surface of drilling cuttings, but there are some problems in the centrifuges. As drum is badly worn, screen is easily clogged, and it cannot continuous operation.Aimed at the problem of filter cake cannot be automatically discharged, combined with the analysis of centrifugal unloading mechanism, we designed the new structure of drum for the centrifuge on the basis of predecessors’ design of centrifuge, and calculated the performance of the centrifuge, preliminary obtained the technical specifications of the centrifuge.Static analysis was carried out on the centrifuge rotation axis and cylindrical screen with the finite element analysis software ANSYS, and the stress intensity under the working condition of the centrifuge was obtained. The result revealed that stress intensity met the design requirements. Then modal analysis was carried out on the drum components and cylindrical screen, according to the results resonance phenomenon in centrifuge workspace would not occur.Established the experiment device to research the effects of operating parameters, mesh numbers on the performance of self-cleaning. Experimental results demonstrated that the self-cleaning efficiency increased quickly when the rotate speed increased and the effect was obvious. Self-cleaning efficiency decreased when the cylindrical screen’s rotation speed increased, and when the rotation speed increased to a certain value it would badly affect the efficiency of self-cleaning. The self-cleaning efficiency was independent of the mesh numbers under the same rotate speed and cylindrical screen’s rotation speed. Self-cleaning efficiency increased when the time in the cylindrical screen increased, and after some time the self-cleaning efficiency of cylindrical screen was stabilize. Self-cleaning efficiency decreased when the weight of brushing cuttings increased, when the brushing cuttings increased too much, the self-cleaning efficiency decreased quickly.Established the experiment device based on forced discharged self-cleaning centrifuge, and studied the effects of operating parameters on the performance of centrifuge. Experimental results demonstrated that within the scope of a certain capacity, dewatering efficiency tends to be constant, when the capacity exceeded a certain value, dewatering efficiency decreased significantly, and the critical point was the biggest capacity of centrifuge. The dewatering efficiency increased quickly when the rotate speed increased. After summarized the various factors affected on the performance of the centrifuge, it could provide some certain basis for the optimal design of the centrifuge.