The horizontal screw centrifuge USES the density difference between solid and liquid phases to accelerate the settling rate of solid particles under the action of centrifugal force to achieve the separation of solid and liquid. Specific separation process for mud and flocculant solution by the inlet pipe to the drum inside the mixing chamber, blend in the flocculation (for sludge before dosing pump or pump pipeline after dosing, have flocculation reaction) in advance, because the rotor (screw and drum) and frictional resistance, high speed rotation of the sludge inside the rotor is accelerated and form a cylindrical liquid ring layer (liquid ring).Under the action of centrifugal force, the solid particles with a larger proportion are deposited to the inner wall of the drum to form a mud layer (solid ring layer), and then the relative speed difference between the spiral and the drum is used to push the solid phase to the cone end of the drum. After pushing out the liquid surface, the sludge can be dehydrated and dried, push to the slag discharge mouth, and the supernate liquid is discharged from the big end of the drum to achieve solid-liquid separation.

Because the centrifuge USES the density difference between solid and liquid phases to achieve solid-liquid separation, the larger the proportion of sludge particles, the easier to separate. Generally speaking, the primary sludge of sewage treatment plant is easy to dehydrate, and the residual sludge is difficult to dehydrate, but the dehydration performance of mixed sludge is between the two. Sludge produced by different sewage quality and sludge obtained by different water treatment technologies will have great differences, so there will be different performance in sludge dewatering.

There are many factors influencing the dehydration effect of horizontal screw centrifuge, and each factor affects the other, so the treatment effect is the result of the comprehensive action of each factor. The selection of centrifuge should be combined with the actual situation of the engineering project, and the adjustment of operation parameters should be taken into account such factors as the optimal moisture content, solid rate and economy of the sludge cake required by the final disposal method of dehydrated sludge cake.