Process Procedures of Sludge Dewatering Centrifuge

Sludge centrifugal dehydrator is a machine that applies the principle of centrifugal sedimentation for sludge concentration or dehydration. It consists of rotating drum, screw conveyor, differential gear, main bearing, bottom frame, liquid-solid phase collecting chamber, upper cover, motor transmission device, frequency converter and other components. The sludge centrifuge has a compact structure, less auxiliary equipment, less land occupation, high solid recovery rate and low turbidity of the separated liquid. It operates in a closed state. The working environment is hygienic and the odor is small. No filter medium is required. It is easy to operate and maintain, and has a high degree of automation. It is particularly important that no or less chemical conditioning agents can be added. Although the power cost is high, the total operating cost is low.

1. Working principles of sludge dewatering centrifuge

After the sludge is fed into the drum by the hollow shaft, it is immediately thrown into the drum cavity under the action of the centrifugal force generated by the high-speed rotation of the sludge dewatering centrifuge. Due to the high density and high centrifugal force, the sludge particles are thrown and attached to the inner wall of the drum to form a solid ring layer. Because of its low density and low centrifugal force, water can only form a liquid ring layer inside the solid ring layer. The sludge in the solid ring layer is conveyed to the cone end of the drum under the slow push of the screw conveyor, and is continuously discharged through the outlet around the drum. The liquid in the liquid ring layer is continuously "overflowed" from the weir mouth and discharged to the outside of the drum to form a separation liquid, which is then collected and discharged out of the dehydrator by gravity.

2. Process procedures of sludge dewatering centrifuge

The sedimented sludge from the sludge thickening tank is crushed by the sludge cutter and then transported by the sludge feed pump. After being measured by the electromagnetic flowmeter, it is combined with the prepared liquid medicine sent by the flocculant dosing system and mixed into the dewatering centrifuge. The sludge is separated into solid and liquid phases after being separated by a dehydrator. The liquid phase (clarified liquid or separated liquid) is directly discharged or returned to the sedimentation tank. The solid phase (dewatered sludge) is discharged by the screw conveyor to the transport vehicle for transportation.

With the centrifugal separator working principle, if the automatic dosing system of flocculant, the powdery flocculant is added from the hopper (material feeder) and added to the preparation tank by the automatic powder feeding device (the colloidal flocculant is directly added to the preparation tank with a metering pump). At the same time, the tap water enters the preparation tank through the flow meter and is automatically prepared into a solution of a certain concentration. The prepared solution flows into the chemical storage tank and is transported by the dosing screw pump. After being measured by the electromagnetic flowmeter, it is mixed with the sludge from the sludge thickening tank through the manifold (or static mixer) and the high-speed rotation of the centrifuge is brought about. Centrifugal force makes the material with high density (solid phase) in the suspension entering the drum to settle and separate under the action of centrifugal force and centrifugal liquid pressure, and enter the dewatering centrifuge together for sludge dewatering.