Application of decanter centrifuge in coal mine field

1 Working Principle
Horizontal screw centrifuge is a screw discharge settling centrifuge. It is mainly composed of a rotating drum with a high speed, a spiral conveyor with a hollow rotating shaft which is the same as the rotating drum and slightly lower than the rotating drum. When the suspension to be separated is sent into the drum by the hollow rotating shaft, it is immediately thrown into the drum chamber under the action of centrifugal force generated by high-speed rotation. The high speed rotating drum produces a strong centrifugal force to stick solid particles that are denser than the liquid phase to the inner wall of the drum, forming a solid layer (because of the ring, called the solid ring layer); Due to its small density and small centrifugal force, water can only form a liquid layer inside the solid ring layer, which is called the liquid ring layer. Because of the different speed of the screw and the drum, there is a relative movement (that is, the speed difference), using the relative movement of the screw and the drum to slowly push the solid ring layer of sludge to the cone end of the drum, and after passing through the dry area, it is continuously discharged from the outlet of the circular distribution of the drum; The liquid in the liquid ring layer is discharged by gravity from the weir continuously "overflow" to the drum, forming the separation liquid.
2 Operation Management
Because the system is a blast furnace gas washing water sludge treatment system, its recovery water quality changes, sludge particles on the equipment wear seriously, and the external influence of uncertain factors, coupled with the system of treatment equipment more types, staggered processing links, the operation of the operator requirements are higher, therefore, to ensure the normal operation of each link, give full play to the role of the facilities and equipment It is necessary to strengthen the daily operation management and have a set of management measures to ensure it. The details are as follows:
2.1 Supervise operation management personnel in daily operation. Familiar with the function of each facility and equipment, handle the nodes of each link well, and strengthen the coordination between the processes.
2.2 According to the mud quality and amount of gas mud, grasp the key links of centrifuge operation:
Decanter centrifuge has a maximum amount of mud and the limit of the maximum amount of solids, the actual amount of mud exceeds the value, the centrifuge will lose the dynamic balance of the solid phase and the liquid phase, the torque is too large, and it will be damaged seriously, so that the centrifuge is overloaded and stopped, so the operation should strictly control the amount of mud and the amount of solids in the decanter. The method of selecting the appropriate feed flow rate: first adjust the feed flow rate to a small value (under frequency conversion control, generally adjusted to 60%~70%), and then start the decanter and work for a period of time, until the solid phase discharge speed is certain. Sample 500 mL at the entrance of the centrifuge to determine the settling ratio of the mud. It is normal to settle at 100~150 mL within 5 min. Otherwise, open the bypass valve to reduce the concentration of the feed. The control of the amount of mud is the main factor in the operation of horizontal spiral centrifuge.