The centrifuge is widely used in the sludge dewatering stage of various sewage treatment plants. The complete set of sludge centrifugal dewatering treatment (complete set of equipment for sludge concentration and dewatering) is an important equipment in urban domestic sewage treatment, sludge treatment in the process of tap water production, and industrial and agricultural sewage treatment projects. It has the integrated processing functions of sludge dewatering and sludge concentration and dewatering.
In the world, a fully enclosed continuous running large-aspect-ratio horizontal spiral discharge sedimentation centrifuge (referred to as a large-aspect-ratio horizontal-screw machine) is generally used as the main body of sludge dewatering. It has the features that other types of sludge dewatering equipment do not have Advantages:
1. Fully enclosed operation, clean and pollution-free on site;
2. The amount of flocculant and cleaning water is small, and the daily running cost is low;
3. The equipment layout is compact and the occupied area is small, which can significantly reduce land acquisition and infrastructure investment.
The selection of polyacrylamide is mainly based on the type of charge carried in the sewage water quality. According to the characteristics of the water quality, the choice of cationic polyacrylamide, anionic polyacrylamide, or zwitterionic polyacrylamide, etc., the process is generally from the experiment The laboratory's small test, the manufacturer's big test, the product selection is determined, and the specific problems are analyzed concretely.
The effect of polyacrylamide for centrifuge processing is good or not. It is critical to choose the right model. When there is a sudden incident on the scene, once the water quality changes, we should treat it calmly. Don’t just look at the problem itself and find a solution. The selection of polyacrylamide itself is a very experimental process. In short, the purpose of the small polyacrylamide trial selection is to recommend the polyacrylamide products suitable for on-site use to customers to meet the requirements of on-site sewage or sludge treatment. Therefore, the polyacrylamide used in the centrifuge must be selected through a small trial.
When centrifuges are used at the site of sewage desilting, we select models through small and medium-scale polyacrylamide tests. When using polyacrylamide in a small test, it should be observed: floc strength, re-flocculation, supernatant quality, reaction speed, etc. The polyacrylamide pilot test should observe: the dosage of chemicals, centrifuge torque and differential speed, sludge flow rate, sludge dryness, centrifuge filtrate, etc.
The following problems will occur at the scene of polyacrylamide for centrifuges, we can adjust according to the corresponding content.
A, black filtrate appears
1. Check the mud feed situation and flow rate. The centrifuge must work within the specified range. It is impossible to have a good water filtration effect during overload operation.
2. Check the differential speed. The lower the differential speed, the stronger the shear. The torque should be adjusted to obtain the proper differential speed.
3. Check the polymer flow rate. In order to resist shear, the floc should be large enough, and the minimum dosage of polyacrylamide should be determined through experiments.
B. The filtrate is whitish or foaming
1. There is not enough solid input to help the centrifuge reduce the differential speed, and the flocculant should be adjusted according to the solid content.
2. Check the torque, torque changes will leave tiny particles in the filtrate, the torque is unstable, and the centrifugal effect is poor.
3. Check the flow rate of polyacrylamide, when the foam appears, it means that the polymer dosage is too large, and the grayish white in the filtrate indicates that the polyacrylamide is not selected properly or the polymer and sludge are not mixed well.
C, low mud biscuit
1. Check the torque set point. If the solid input is too low or too high, it is impossible to obtain good results at the same set point. The differential speed or torque value should be adjusted according to the situation.
2. Check the height of the gate. If the solid content in the mud is low, the hydraulic load will become higher. Adjust the height of the gate to increase the output of filtrate.
3. Check the floc strength. If the flocculant is not selected properly, the floc will be unstable and a good dehydration effect cannot be obtained. Lebang polyacrylamide manufacturer recommends that the selection of polyacrylamide must be determined through a small trial.