Views: 0 Author: Site Editor Publish Time: 2020-04-20 Origin: Site
1. Sludge pump and liquid pump should use screw pump instead of centrifugal pump
The sludge pump of the sludge dewatering system of the diaphragm filter press originally used a mud pump (belonging to a centrifugal pump). During operation, the pump will not block the mud or the pump will leak. During operation, it is often necessary to flush and repair the pump. The workload of the pump is also very large. After technical research and actual operation test, it is found that the use of screw pump to transport sludge has the advantages of stable flow, stable pressure and no leakage. Later, we also controlled the frequency conversion of the screw pump, which greatly improved the sludge flow and pressure. The accurate digital control has created a good premise for the stable operation of the membrane filter press, and it is currently operating well.
At the same time, we believe that the chemical liquid pump should also use a screw pump with frequency conversion speed regulation device. If a plunger pump or diaphragm pump is used, the viscosity of the PAM will adhere to the inlet and outlet ball check valves of the pump, thereby forming a valve. Failure, cleaning and maintenance work is heavy, has not been modified. The piston pump is still used. During operation, the valve often fails and the pump is blocked.
2. The filter belt adjustment device should be equipped with a mud control device
In the initial stage of the membrane filter press, the filter belt is often skewed, which often causes the filter belt to be caught in the squeeze roller and damaged, thereby greatly shortening the service life of the filter belt. Later, our analysis found that the main reason for the deviation of the filter belt is the failure of the filter belt adjustment device. After installing the anti-mud device on the membrane filter press, the problem of offset of the filter belt is solved.
3. The filter belt should be selected from the filter belts through the interface connection method. Do not use filter belts with metal buckle connections.
The filter belt with metal buckle connection interface will be continuously worn by the scraper in actual operation, and it is easy to break from the interface, thereby damaging the mesh belt. And the operating cycle is only about 3 months. When the filter belt ran away, the filter belt even broke within a month. After replacing the filter belt with the interface connection mode, this problem was solved. The operating cycle of the filter belt is increased from 6 months to 1 year, mainly because the flexibility of this type of filter belt interface is very strong and difficult. Suffered damage.
4. The tension of the lower filter belt should be less than the tension of the upper filter cloth.
The difference in tension between the upper and lower filter belts has an important influence on the sludge dewatering effect. The higher pressure will press the mud cake to the lower pressure side, adjust the tension of the filter belt, so that the tension of the lower filter belt is less than the tension of the upper filter belt, and can be freely peeled through the lower filter belt, which can improve the cake yield . In actual operation, we adjusted the tension of the upper filter belt to 40-50 psi and the tension of the lower filter belt to 30-40 psi, which achieved a good sludge dewatering effect.
5. The pressure of the flushing water of the filter belt should be increased. Install the flushing tube in the necessary position to ensure that the filter belt is flushed. Washing effect
In the sludge dewatering operation of the membrane filter press, the moisture content of the mud cake is often very high, which causes the mud cake to be seriously turbid during external transportation, which affects the environment and does not meet the environmental protection requirements. One of the main reasons the technicians found was that the filter belt was not completely rinsed out and there was a blockage, which caused the drainage to be blocked and the moisture content of the mud cake to be high. When the pressure of the filter belt flushing water was increased from 0.6Mpa to 0.8Mpa, and the flushing water pipe was installed before the filter belt entered the gravity dehydration zone, the dewatering effect of the sludge was improved, and the increase in the moisture content of the mud cake was also obtained. reduce.
6. The belt speed should be adjusted in time to ensure the effect of sludge dewatering
The belt speed also has a great influence on the sludge dewatering effect. When the water content of the mud is high or the mixing effect of sludge and liquid is not good, the belt speed should be reduced, the drainage time of the gravity dehydration area should be extended, and the sewage discharge should be prevented. In the pressing stage, the mud is extruded from both sides of the filter belt. Under normal circumstances, the belt speed is 4-6m / min, and the dehydration effect is better.