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Introduction about Differential Speed of Decanter Centrifuge

on . Posted in News

The differential of the screw speed and bowl speed in the decanter centrifuge directly affects the slag discharge capacity, the degree of muddy dryness, and the quality of the filtrate. It is one of the important parameters in the decanter centrifuge that needs to be adjusted according to the operating situation.

Increasing the differential speed is conducive to improving the slag discharge capacity, but the dewatering time of the sediment will be shortened, and the moisture content of the mud cake will be large after dehydration. Decreasing the differential speed will increase the thickness of the sediment, the sediment dewatering time will increase, and the moisture content of the mud cake will decrease after dehydration. At the same time, the spiral will have less disturbance to the material in the clarification zone, and the quality of the filtrate will be relatively better. To prevent the slag discharge from reducing the material blocking phenomenon caused by the sediment in the centrifuge can not be discharged in a timely manner, to prevent a large amount of mud in the filtrate, then you must reduce the amount of feed or increase the differential speed.

Some types of equipment have the function of speeding up slag discharge automatically. After the set torque reaches a certain limit value, the equipment will automatically reduce the amount of mud and medicine, increase the differential speed, and quickly push out the accumulated mud ring layer. After the torque is reduced to a certain value, the flow and difference Degrees automatically return to normal. This is a measure to effectively protect the decanter centrifuge. However, in the long-term operation, this situation should be avoided frequently, because it is easy to make the decanter centrifuge often in an condition of unstable flow and unstable differential speed. The fluctuations in the process will affect the processing effect and reduce the processing capacity. 

Therefore, the differential speed should be determined according to the nature of the material, the amount of processing capacity, the processing requirements and the structural parameters of the decanter centrifuge. To put it simply: there is a contradiction between the processing capacity and the processing effect. To increase the processing capacity of the decanter centrifuge, it is necessary to increase the differential speed ratio, but the degree of muddy biscuits may be reduced. Capacity, so the on-site debugging work is to find the best equipment operating conditions parameters that meet the actual sludge properties of the respective site, in order to achieve the dual purpose of the highest equipment operating efficiency and the best treatment effect. There is no simple data to calculate, only rely on long-term actual debugging to accumulate experience, and adjust in time according to changes.

At the same time, within a certain range, the control of the degree of speed difference and the control of the amount of flocculant dosing complement each other. When a certain degree of muddy dryness is required, if the degree of difference is reduced, the amount of flocculant dosing can be saved. To put it simply, increasing the pressure of equipment treatment will reduce the pressure of using flocculant. Therefore, the proper use of the lowest possible difference can reduce the consumption of flocculant to a certain extent. As the saying goes, "If the equipment works well, the medicine is saved, and if the decanter centrifuge is not well operated, the medicine is spent." It depends on the design and processing accuracy of the equipment itself, and it also involves the control of the operating parameters of the equipment.

For decanter centrifuges with automatic adjustment of differential degrees, the parameter settings of differential degrees should be determined in combination with long-term use, and amended in time according to various changes that may occur.