Horizontal spiral centrifuge is abbreviated as horizontal spiral centrifuge. It is an efficient centrifugal separation equipment. The drum and the spiral rotate at a certain differential speed in the same direction and high speed. The material is continuously introduced into the inner cylinder of the conveying spiral by the feed pipe, and then enters the drum after acceleration. Under the action of the centrifugal force field, the heavier solid phase is deposited on the drum wall to form a sediment layer. The conveying spiral continuously pushes the deposited solid substance to the cone end of the drum and discharges it out of the machine through the slag discharge port. The lighter liquid phase forms an inner liquid ring, which continuously overflows the drum from the big end overflow port of the drum and is discharged out of the machine through the discharge port.
The ratio of the settling velocity of the solid particles in the suspension of the drum under the action of centrifugal force to the settling velocity under the action of gravity is called the separation factor. Under different materials and operating conditions, the separation factors selected are different. If the material solid particle size is small, the solid-liquid density difference is small, the liquid viscosity is large (low temperature), the separation factor is selected a little higher; the material solid particle size is large, the solid-liquid density difference is large, and the liquid viscosity is small (high temperature), the separation factor of the automatic centrifuge is selected to be lower; if flocculant is added during the separation process, the separation factor can be lower.
In order to stabilize the speed of the difference between the screw and the drum, the centrifuge is equipped with a differential. When the drum speed remains unchanged, changing the speed of the differential input shaft can adjust the difference speed between the screw and the drum, and then adjust the separation effect of the decanter centrifuge. In the case of other conditions unchanged, when the differential speed is low, the spiral push speed will decrease, the residence time of the solid phase in the dehydration zone will increase, and a solid phase with lower moisture content can be obtained. As the screw push speed is reduced, its push can be reduced, and the clarity of the liquid phase will be reduced. And vice versa.
The interval between the liquid level in the drum and the wall of the drum is the "height" of the liquid level, which is called the depth of the drum liquid pool. The inner diameter of the overflow plate is different, the depth of the liquid pool is also different, and the length of the dehydration area and the sedimentation area in the drum are also different, thus changing the sedimentation and dehydration capacity of the centrifuge. Under the condition that other conditions remain unchanged, the use of overflow plates with larger inner diameter will reduce the depth of the liquid pool, shorten the length of the settling area, and reduce the settling capacity of the centrifuge. However, it will increase the length of dehydration zone, increase the dehydration time of solid phase and improve the dehydration performance of decanter centrifuge.