The problems of high moisture content and "runny" in the plate and frame sludge descementing cake, the possible causes and solutions are as follows:
Reasons for high water content and solutions
Cause：
Sludge impurities: The sludge contains a certain proportion of impurities, such as soil, slag or other impurities, which will increase the pressure of the mud cake during the filtration process, thereby increasing the moisture content of the mud cake.
Equipment blockage: When the plate and frame filter press is blocked seriously, the mud cake will be pressed out of too much water.
Insufficient pretreatment: Before the sludge enters the filter press, it is not fully pre-treated, such as dehydration, drying and other steps, resulting in high sludge moisture content.
Improper equipment debugging: The newly put into operation of the plate and frame filter press equipment is not properly debugging, which may lead to high moisture content of the sludge cake.
Improper operation: The filter press is not used according to the operating procedures, or the compression force is insufficient, resulting in the reduction of the filter effect.
Solution：
Improve sludge quality: minimize the impurity content in the sludge and improve the homogeneity of the sludge.
Regular cleaning equipment: regularly check and clean the plate and frame filter press to prevent clogging.
Enhanced pretreatment: sufficient pretreatment of the sludge, such as dehydration, drying, etc., to reduce the moisture content of the sludge.
Debugging equipment: The newly put into production of the plate and frame filter press should be fully debugged to ensure that the components work normally.
Standard operation: The filter press is used in strict accordance with the operating procedures to ensure that the compression force is sufficient.
Causes and Solutions of "Runny heart" problem
Cause：
Uneven density of filter cake: In the working process of the plate and frame filter press, solid particles continue to accumulate in the filter chamber and gradually form filter cake. Because the density of the cake is not uniform, the density of the central part is often low, and the density of the edge part is high. When the cake is pressed, the solid particles in the center are subjected to less pressure, and the solid particles in the edge are subjected to greater pressure, resulting in the solid particles in the center of the extrusion, forming a "runny" like mud.
Filter cloth problem: The aperture of the filter cloth is too large or the material is not suitable, which will lead to the uneven distribution of solid particles on the filter cloth, and further aggravate the uneven density of the filter cake. Clogging or wear of the filter cloth will also affect the formation and compaction effect of the filter cake.
Insufficient pressure of the pump: if the mud cake pressed by the filter press is normal at the beginning, after a period of time, the mud cake appears "runny", it may be because the pump has been running for a long time, the impeller is worn, resulting in insufficient pressure of the pump.
Improper sludge conditioning: improper selection of sludge conditioner or not fully mixed with sludge may also lead to "runny" mud cake.
Solution：
Optimize filter cloth selection: Select the appropriate filter cloth to ensure that its aperture and material match the material to be processed.
Regular inspection and replacement of filter cloth: avoid clogging or wear of filter cloth to ensure uniform formation of filter cake.
Adjust the pressing force: During the pressing process, adjust the pressing force appropriately to ensure the uniform density of the cake.
Replace the feed pump: If the pump pressure is insufficient, it is recommended to replace the feed pump.
Improve sludge conditioning: Select the appropriate sludge conditioner and ensure that it is fully mixed with the sludge.
In summary, in view of the problems of high moisture content and "runny" in the plate and frame sludge descementation cake, it is necessary to conduct a comprehensive analysis and solution from many aspects such as sludge quality, equipment maintenance, pretreatment, operation specifications and filter cloth selection.