The appearance of "runny" mud cake and excessive water content may be caused by a variety of factors. The following is a specific analysis of these reasons:

1. Feed factor

Low feed concentration: the dehydration effect of the filter press is closely related to the feed concentration. When the feed concentration is low, the water content in the mud cake is relatively high, resulting in a high water content of the mud cake, and it is easy to form a "runny" phenomenon.

Material properties: The dehydration performance of different materials is very different. Some materials contain more hydrophilic substances or impurities (such as soil, slag, metal ions, sulfides, oxides, hydroxides, etc.), which will increase the difficulty of dehydration, resulting in too high water content of mud cake.

Two, filter press operating factors

Insufficient press pressure: The dehydration process of the filter press is to squeeze water out of the material by applying pressure. If the pressing pressure is insufficient, the water in the mud cake can not be fully extruded, resulting in a higher water content of the mud cake.

Insufficient press time: the dehydration process of the filter press takes a certain amount of time. If the pressing time is insufficient, it will also lead to the water in the mud cake can not be fully extruded, thus affecting the drying degree of the mud cake.

Clogging of filter cloth: Filter cloth is a key component in the dehydration process of filter press. When the filter cloth is blocked, the water in the mud cake cannot be discharged smoothly through the filter cloth, resulting in a higher water content of the mud cake. In addition, the material and permeability of the filter cloth will also affect the dehydration effect.

Improper operation: The skills and experience of the operator also have a certain impact on the moisture content of the mud cake. Improper operation may lead to unreasonable setting of parameters such as pressing pressure and pressing time, thus affecting the drying degree of mud cake.

Three, filter press equipment factors

The equipment is not debugged well: the internal components of the filter press equipment that has just been put into operation may not have reached the normal working state, and if it is not debugged or improperly debugged, it is easy to lead to high moisture content of the sludge cake.

Aging or damage of equipment: The filter press used for a long time may have aging or damage of parts, such as rust of the filter plate, damage of the filter cloth, etc., which will affect the dehydration effect.

4. Other factors

Insufficient sludge pretreatment: The sludge needs to go through a pretreatment step to remove most of the water before entering the filter press. If the pretreatment is not sufficient, it will lead to insufficient dehydration, resulting in high sludge moisture content and non-forming problems.

The mud pump flow is too large: in the late stage of dehydration work, the flow of the mud pump will affect the thickness of the mud cake. If the mud pump flow is too large, it will cause the mud cake thickness is too large, which affects the dehydration effect. At this time, the thickness of mud cake can be reduced by reducing the flow rate of mud pump, so as to improve the hardening degree of mud cake.

To sum up, in order to solve the problem of "runny" mud cake and too high moisture content, it is necessary to conduct comprehensive analysis and improvement from many aspects such as feed concentration, material properties, filter press operation, equipment status and sludge pretreatment.