The operation of the Concentration Equipment must be adapted to the fluctuations in the process feed stream - the control of the disturbance - to provide a clear overflow and a thick underflow. This control is achieved by manipulating the flocculant addition and underflow withdrawal rate (usually pumping). The addition of the flocculant should be adjusted according to the input of the solids, mainly due to the processing speed. A simple constant speed feed system can use flocculant pump speed control, while a more advanced control system uses a proportional controller to maintain a constant "gram per ton" dose rate.
Primary sludge concentration and flotation concentration are often used in the activated sludge concentration process. The gravity concentrator will be designed for hydraulic and solid loads. The design principle is the same as that of the sedimentation tank. The use of chemical additives (lime or polyelectrolytes) allows for higher loading rates. The minimum residence time and sludge volume divided by the daily sludge removal (representative sludge is maintained in the sludge layer) is typically less than two days.
The centrifuge is acclimated for carrion absorption and dehydration. Centrifugal force is the precipitation of particles in aqueous carrion beneath centrifugal force. The appliance of the centrifuge is bound to carrion in the activated sludge. The advantage of centrifugal agglomeration is that it thickens some of the awkward sludge. Disadvantages of carrion apply centrifuges are the costs associated with power, maintenance, and accomplished operators.
Flocculants are usually alien afore the thickener and thickener thickener are fed into the can. The optimum dosage for the flocculant is usually bent by branch evaluation, and the surgical changes are afflicted by the solid matrix, atom admeasurement and The access of institutional facts. ORS. If a coagulant is used, this is usually the point at which the upstream flocculant is added.
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