The shield construction of sewage treatment system is started from the source of sewage control, through the shield machine with cyclone desander and sedimentation box for sand removal, sewage turbidity, initial solid-liquid separation, sand removal of wastewater by sewage pipes to the wellhead flocculation precipitation tank, precipitation of pumping water to the ground again processing. The belt type filter press sewage treatment system see Figure 2, from the underground system, the three part of the ground precipitation precipitation pool and mud water separation system.
Underground sedimentation system including the underground sedimentation tank and shield machine system.
Usually there is a deposit box in the tail of the shield machine, the sewage flow pumping to the deposit box, usually do not do any treatment through the sewage pipe to the wellhead sedimentation tank, the sedimentation tank does not play much of the sedimentation, and the untreated sewage sludge sand deposition in the sewage pipe, the pipe is often blocked phenomenon. Therefore, increasing the cyclone desander as a primary settling tank in the system dehydration treatment on the shield machine, sand removing, turbidity, solid-liquid separation of the source of the sewage, the sewage pipe is conducive to smooth. Cyclone desander has high decontamination efficiency, convenient cleaning, has the advantages of small resistance, and constant etc.. Cyclone desander according to the fluid in the solid particles in the desander in the screening principle of rotating flow when made. A new separation device to filter combination, when the water under pressure from the water inlet to cut into the desander equipment, produced a strong rotation, due to the different density of sand and water, in the action of the centrifugal force, centripetal force, fluid drag force, the low density water rises by the outlet, sand density large equipment from the bottom drainage port. The individual tiny particles along the water flow together are filtered by the second level filtering device to achieve the purpose of removing the sand.
The sedimentation tank form, according to the position of the design of field wellhead, sedimentation tank placed in the main hook can reach the position of gantry crane. The use of alum to speed up the mud and sand sedimentation, precipitation of water pumping on the ground precipitation and precipitation in the pool, sedimentation tank sludge through the gantry cranes to ground slag drained ponds.
The ground sedimentation tank is the four level of the advection sedimentation tank. Four first class for the advection grit chamber in the sedimentation tank, coarse components in sewage by gravity sedimentation and filtration; the second level for the flocculation pool, through the mud pump the first filtered sewage drainage into two pools, coagulant added in flocculation pool in sewage sludge in the production of chemical the role of water into the floc, separated into upper pool, sludge and water are separated in the primary, primary separation after water is pumped to third to precipitate, flocculent mud is pumped to the belt filter press dewatering machine to handle, and for different types of sludge with different concentration and dosage of flocculant in order to obtain more scientific and reasonable and economical effect; third pool for the mud water separation tank, set the belt filter press dewatering machine of the pool, through the pump can be flocculated sludge and sewage pool at all levels is pumped to the belt filter press dewatering machine, sludge and water Separation of water back into the tank, sludge and solid chemical pollution caused by compacted dehydration of low water content is discharged outside the pool; fourth level pool Weiqing pool, third stage pressure filter in the supernatant was full to the elevation after flowing into the clean water tank, after Shimizu Ikemizumitsu from the sedimentation tank outlet through a ditch discharged into the municipal drainage pipeline. The pool of water can also be used for washing and cleaning facilities, realize the reuse of water resources, saving water.