The sludge dewatering centrifuge is a solid-liquid separation two-phase centrifuge. It is mainly used to realize the dehydration and solidification of sludge in a mud system, and realize the two-phase separation of sludge and water. This article mainly introduces: the working principle of the sludge dewatering centrifuge, the process flow of the sludge dewatering centrifuge and the advantages and disadvantages of the sludge dewatering centrifuge.
Working principle 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. The sludge particles have high density and high centrifugal force, so they are thrown onto the inner wall of the drum to form a solid ring layer; because of the low density and low centrifugal force, the water can only form a liquid ring layer inside the solid ring layer. The sludge in the solid ring layer is transported 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 to the drum. In addition, the separated liquid is formed, and then collected and discharged out of the dehydrator by gravity.
Process flow of sludge dewatering centrifuge
The precipitated sludge from the sludge tank is crushed by the sludge cutter, transported by the sludge feed pump, measured by the electromagnetic flowmeter, and combined with the prepared chemical solution sent by the flocculant dosing system. Mixed into the centrifugal dewatering machine; the sludge is separated into solid/liquid two-phase by the dewatering machine, the liquid phase (clarified liquid or separated liquid) is directly discharged or returned to the sedimentation tank, and the solid phase (dewatered sludge) is discharged by the screw conveyor To transport vehicles out of the country.
In 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; at the same time, tap water flows through the flow. The meter enters the preparation tank and automatically prepares a solution with a certain concentration (about 0.08–0.15%); the prepared solution flows into the drug storage tank and is delivered by the dosing screw pump. After being measured by the electromagnetic flowmeter, it passes through the manifold (or static Mixer) mixed with the sludge from the sludge thickening tank and the centrifugal force caused by the high-speed rotation of the centrifuge, so that the dense material (solid phase) in the suspension entering the drum is affected by the centrifugal force and centrifugal pressure. The sedimentation and separation will enter the dewatering centrifuge for sludge dewatering.
Advantages of sludge dewatering centrifuge
Compact structure, less auxiliary equipment, less land occupation; high solid recovery rate, low separation liquid turbidity; operation in a closed condition, sanitary working environment, low odor; no filter medium, convenient operation and maintenance, and high degree of automation; special It is important to add no or less chemical conditioning agent. Although the power cost is higher, the total operating cost is lower.
Disadvantages of sludge dewatering centrifuge
The noise of this kind of dewatering machine is generally large, and the moisture content of the sludge after dewatering is relatively high, and it is not easy to separate when the density difference between solid and liquid is small. If the sludge contains sand and gravel, it is easy to grind the centrifuge fluid and damage the equipment.