Sludge pressing of Belt Filter Press is a dynamic operation process. There are several factors that affect the amount and speed of sludge.
1. Sludge moisture content of thickener
The moisture content of sludge in the thickener is lower than 98.5%, and the sludge discharge speed of the sludge press is much higher than 98.5. If the moisture content of sludge is lower than 95%, the sludge will lose its fluidity, which is not conducive to sludge pressing. Therefore, it is necessary to reduce the water content of sludge in the thickener, but the water content should not be less than 95%.
2. Proportion of activated sludge in sludge
Activated sludge particles are larger than those after anaerobic nitrification, and free water is better separated from sludge after mixing with PAM. Through the sludge pressing operation, it is found that when the proportion of anaerobic nitrified sludge in the thickener is high, the solid-liquid separation effect is not good after mixing sludge and drugs. Too small sludge particles will cause the low permeability of the filter cloth in the concentration section, increase the burden of solid-liquid separation in the pressure section, and reduce the output of the sludge press. When the proportion of activated sludge in the thickener is high, the solid-liquid separation effect in the thickening section of the sludge press is good, which reduces the burden of solid-liquid separation of the filter cloth in the pressure filtration section. If there is much free water flowing out of the concentration section, the flow of the sludge drug mixture of the upper machine can be appropriately increased, so as to increase the sludge output of the sludge press in unit time.
3. Mud drug ratio
After adding PAM, the sludge is initially mixed through the pipeline mixer, further mixed in the subsequent pipeline, and finally mixed through the coagulation tank. In the mixing process, the sludge agent separates most of the free water from the sludge through the turbulent effect in the flow, and then achieves the effect of preliminary solid-liquid separation in the concentration section. Free PAM should not be contained in the final mud drug mixed solution.
If the dosage of PAM is too large and PAM is carried in the mixed solution, on the one hand, PAM is wasted, on the other hand, PAM sticks to the filter cloth, which is not conducive to the washing of the filter cloth by spraying water, and finally leads to the blockage of the filter cloth. If the dosage of PAM is too small, the free water in the mud drug mixed solution cannot be separated from the sludge, and the sludge particles block the filter cloth, so the solid-liquid separation cannot be carried out.
Post time: Jul-14-2022