The mud cake sludge pressed by the plate and frame filter press is not formed, which may be caused by a variety of reasons, the following are some common reasons and analysis:
One. Sludge conditioning problem
Lack of sludge conditioner: the sludge is not added before entering the plate and frame filter press, especially the biochemical sludge, and the flocs formed by it are easy to deform under the action of external forces, resulting in clog of the filter cloth and affecting the mud press forming.
Insufficient mixing of sludge and conditioner: insufficient mixing time of sludge conditioner and sludge or improper dosing method, resulting in uneven mixing and affecting the sludge dewatering effect.
Improper selection of sludge conditioner model: The selection of the wrong sludge conditioner model will cause insufficient rigidity of the formed floc, which is easy to deform under external force, and is not conducive to mud pressing.
No modification of hydrophilic groups on the sludge surface: The surface of biochemical sludge contains a large number of hydrophilic groups, which need to be modified by conditioning agents to improve the dehydration efficiency and reduce the water content. If not modified, it will affect the dewatering effect of the sludge, resulting in the mud cake is not formed.
Two, sludge properties
The sludge solid content is too low: the sludge moisture content is too high, resulting in insufficient solid components in the sludge, and it is difficult to form a stable mud cake.
The sludge filtration water is poor, the specific resistance is large: the sludge filtration water is poor and the specific resistance is large, resulting in dehydration difficulties, and the mud cake is difficult to form.
Excessive impurities in the sludge: the sludge contains a certain proportion of impurities, such as soil, slag or other impurities, which will increase the pressure of the mud cake, thereby increasing the moisture content of the mud cake, resulting in the mud cake is not formed.
Three, equipment operation and maintenance problems
Poor state of the filter cloth: the filter cloth is damaged, blocked or improperly selected, which will affect the filtration effect and lead to the mud cake not forming.
Improper pressure setting: The pressure setting of the filter press is too low, which may lead to insufficient sludge dehydration and the mud cake is not formed.
Insufficient equipment maintenance: the plate and frame filter press needs regular maintenance and maintenance, such as cleaning the filter cloth and checking the tightness. If the maintenance is insufficient, the performance of the equipment may be degraded and the forming effect of the mud cake may be affected.
Four. Other factors
Insufficient pretreatment: Before the sludge enters the filter press, it needs to be pre-treated, such as dehydration, drying and other steps. If the pretreatment is not sufficient, it may lead to too high moisture content of the sludge, and it is difficult to form a stable mud cake.
Changes in external factors: changes in external factors such as upstream process, temperature, acid and alkali may lead to changes in sludge properties, thus affecting the dewatering effect of sludge and the forming effect of mud cake.