Application of a 500 m² Quick-Opening Truck-Mounted Chamber Filter Press in Piling Mud Treatment for the South-to-North Water Diversion Project

The Middle Route of the South-to-North Water Diversion Project is a major national strategic water conservancy project. The water quality safety of its core water source, Danjiangkou Reservoir, is directly related to the drinking water safety of hundreds of millions of people along the route. Therefore, construction environmental protection requirements are extremely strict, and “zero pollution” must be achieved. In the construction of bridges and water conservancy facilities along the South-to-North Water Diversion Project, pile foundation construction is a fundamental part. However, bored cast-in-place pile construction generates a large amount of mud. If this mud is not effectively treated, once it leaks or is discharged, it will cause serious pollution to the water bodies in the water source protection area.

Traditional mud treatment methods mostly use on-site pits and ponds, natural drying, or off-site disposal. These methods have prominent problems such as low treatment efficiency, mud leakage, and environmental pollution. Especially in the construction of the water source protection area of the South-to-North Water Diversion Project, mud sedimentation tanks and mud circulation tanks are required at both ends of bridge piers. After sedimentation treatment, the supernatant is recycled and not discharged, and the dried mud cake is transported off site for disposal. It is strictly prohibited to discharge construction wastewater and waste slag into the main canal of the South-to-North Water Diversion Project. To this end, the project introduced a 500 m² quick-opening truck-mounted chamber filter press and a complete mud treatment system, achieving efficient on-site solid-liquid separation of piling mud and “zero discharge” of mud.
 

Equipment Configuration and System Composition

The mud treatment system equipped for this project uses a 500 m² quick-opening truck-mounted chamber filter press as its core and integrates the following main equipment:

Core Filter Press System. The 500 m² quick-opening chamber filter press adopts a Model 1500 specification, with a filtration area of 500 m². The equipment uses a quick-opening plate-pulling structure. A servo motor drives the rapid plate-pulling device, and the plate pulling speed can reach 2–3 seconds per plate. Combined with a filter cloth rapping device, the filter cake falls off quickly, greatly shortening the auxiliary unloading time.

Mud Tank and Agitation System. The supporting mud tank is used for the collection, storage, and conditioning of piling mud. After flocculation reaction and sufficient agitation in the tank, the mud is conveyed by a screw pump or plunger mud pump to the filter press for solid-liquid separation.

Belt Conveyor. A belt conveyor is arranged below the filter press. The dewatered filter cake falls directly onto the conveyor belt and is transported out of the equipment, realizing continuous discharge, reducing manual transfer links, and improving operating efficiency.

Rain Shelter and Platform System. To adapt to the field construction environment, the entire set of equipment is equipped with a rain shelter and an operating platform, ensuring the continuity of construction during the rainy season and providing a safe working space for operators, thus ensuring stable operation of the equipment under complex climatic conditions.
 

Process Flow

The mud generated by piling construction is pumped through pipelines to a mud tank for centralized collection. Flocculants are added to the mud tank for conditioning, prompting fine particles in the mud to aggregate into larger flocs and improving the subsequent filter-press dewatering effect. The conditioned mud is conveyed by a dedicated feed pump to each filter chamber of the 500 m² quick-opening chamber filter press. Under the action of the hydraulic system, the filter plates are pressed tightly to form sealed filter chambers. The mud is dewatered under a working pressure of 0.6–1.8 MPa. Solid particles are retained by the filter cloth to form filter cakes, while clear water passes through the filter cloth and is collected for reuse. After one filtration cycle is completed, the quick-opening plate-pulling mechanism rapidly opens the filter plates, and the filter cakes fall onto the belt conveyor below and are transported to a designated storage area. The filtrate (clear water) returns through pipelines to a clear water tank for reuse in construction or discharge after meeting standards.