The centrifuge is composed of a bowl rotating at high speed, a scroll that runs in the same direction as the bowl and has a certain speed difference, as well as a differential, a base, a feeding and discharging system, etc. The sludge and flocculant enter the bowl after being mixed in a specially designed feeding chamber. Under the action of centrifugal force, the flocculated particles are quickly separated and sedimented in the sedimentation zone, and the clarified liquid is discharged through the overflow hole at the end of the bowl. The sedimented solids, after being squeezed and dewatered by the BD baffle, is pushed by the scroll conveyor to the drying section of the bowl for further compression, and then discharged through the slag outlet. The dewatering time of the solids in the bowl can be controlled by adjusting the differential speed between the scroll and the bowl.
|Skid-mounted Sludge Dewatering Integrated System||Application of LW Series Decanter Centrifuge in Sewage Plant|
Bowl speed: The bowl is designed with high speed and large separation factor, which can effectively clarify tiny particles with size ≥5μm.
Length-diameter ratio: The actual effective length-diameter ratio of the bowl is ≥4, and the sedimentation distance is long, which increases the clarification and dewatering time of the sludge in the bowl.
BD baffle: There is a circular baffle between the scroll sedimentation section and drying section, which squeezes the sludge in the settling section into the drying section, so that the moisture content of the sludge is lower; meanwhile, it cuts off the connection between the sludge and the clarified liquid. The depth of the liquid pool can be greater than the slag outlet, and the deeper the liquid pool is and the longer the process takes, the better the clarification effect is.
MAIN TECHNICAL PARAMETERS
ELECTRICAL CONTROL SYSTEM
The PLC (programmable controller) is employed in the control system of the sludge dewatering equipment for the full-automatic or manual operation, operation monitoring, fault alarm and interlocking protection, etc. of the centrifugal flocculant preparation and dosing device, cutting machine, feed pump, flow meter, etc.
The system start/ stop, automatic/manual operation, separation, cleaning and shutdown functions can be carried out according to preset programs and personalized settings;
It can automatically adjust the feed volume with the constant torque;
It can automatically increase or decrease the differential speed to prevent material blocking according to the changes in the pushing torque;
The hydraulic differential system automatically adjusts the differential speed according to the pressure change of the hydraulic driving system to control the differential speed;
It automatically proportions the flocculant preparation concentration according to the predetermined concentration, and has the function of continuous and stable quantitative dosing;
A large-size color touch screen is available for operation and it can display the working parameters of the equipment in real time.
Crushing and Cutting Machine
This machine is mainly used to smash large pieces of wood, textiles, plastics, rubber, bones, leather, glass, etc. in the sludge (with a solid content of ≤5) so that the feed pumps, centrifuges and instruments in the downstream system can operate normally. It is featured by high treatment capacity, low energy consumption, long service life, etc.
The pump is a positive displacement transfer pump, whose screw with large lead, great tooth depth and small spiral inner diameter pushes the conveyed medium from the suction end to the discharge end along the axial direction. Made of highly wear-resistant materials, it is mainly used for the transfer of sludge with a solid content of 0.2~5% and flocculants, and its discharge flow rate can be adjusted by a frequency converter.
Shaftless Screw Conveyor
LS shaftless screw conveyor is mainly composed of a driving device, shaftless spiral blades, a U-shaped replaceable wear-resistant liner plate and a rack. It is mainly used to transport the dewatered cake from the discharge outlet of the centrifuge to the outdoor storage yard or the transportation vehicle. The whole work is done in an airtight state to keep the environment clean.