Horizontal Screen Scroll Centrifuge

The horizontal screen scroll centrifuge is composed of a drive unit located in a bearing housing, the screen retaining basket, the screen element, the transport worm and the product housing enclosing the rotating parts.

Inside the basket and screen is a concentrically located worm where the flight tips are set at a clearance of 0.5 – 4 mm from the screen surface.

The solids/liquid mixture flows into the horizontal screen scroll centrifuge via a central feed pipe to the inside of the worm. The interior of the worm has a feed cone that preaccelerates the slurry and also distributes it uniformly onto the screening element inside the rotating basket.

These components make up the rotating wetted parts which are of single bearing design cantilevered from the drive housing. The worm rotates at a slightly different speed than the screen basket which results in uniform product acceleration and distribution. This makes the machine very insensitive to fluctuations in the feed concentration and other operating conditions.

The solids/liquid mixture enters the rotating components in the area of the smallest diameter and the majority of liquid is separated through the screen.

In this area the circumferential speed is lowest resulting in smaller power demand compared to cylindrical design machines for the same purpose.

Most solids will slide toward the largest diameter under the influence of centrifugal force, where they are discharged into the product housing over the open basket end. If the solids try to stick to the screening surface, the worm pushes them forward and if the solids try to slide out too quickly, the worm holds them inside the basket. The transport worm acts as a control mechanism by regulating the solids` sliding speed and retention time. If the coefficient of friction of the wet solids is low, the flights hold the solids back, and near the discharge end of the screen basket if the dewatered solids friction force is high against the screen, the worm will advance the solids to discharge.