Dewatering centrifuge with surrounding spray dryer having seal between housing and centrifuge drum

摘要

Sludges are dewatered and dried in a solid bowl screw centrifuge, the ejection zone for densified material forming the dispersion member of a spray dryer, with fixed housing surrounding the centrifuge drum. The dryer housing is sealed at both end faces (15) against the rapidly rotating centrifuge drum by a seal comprising a rotary sealing ring (17) and a flexible expansion joint (18). The rotary seal is not attached to the dryer housing but is connected to the housing by displaceable sealing members (24). Pref. the rotary seal is fastened to the same support as the centrifuge rotor e.g. frame (22). Rotary seal is pref. a non-contact seal with narrow gap e.g. labyrinth seal or a contact seal e.g. sliding ring seal, not attached to the dryer housing. The device avoids damage due to mechanical contact with rotating faces and accommodates expansion, contraction and vibration.