Patent ID: 7143690
Filing Date: 2006-12-05
Classification: B30B

Abstract:
1. A screw compressor for compressing and separating liquid from matter that passes through the screw compressor, the screw compressor comprising: a screw having a longitudinal direction and an outer threading, the outer threading having a pitch, wherein the pitch decreases in the longitudinal direction of the screw; a casing that encases the screw, the casing having an inner side that faces the thread on the screw so that matter can be fed forward through the screw compressor between the screw and the inner side of the casing in a direction from an inlet end of the screw compressor where the pitch of the screw thread is greater, to an outlet end of the screw compressor where the pitch of the screw thread is smaller; appliances on the inner side of the casing, that are arranged to prevent matter that passes through the screw compressor from rotating along with the screw but instead to pass essentially straight ahead in the longitudinal direction of the screw; a conduit for liquid supply arranged inside the screw and provided with a mouth on the outside of the screw so that liquid can be fed through the screw and be supplied to matter that passes through the screw compressor, the mouth being arranged on the outer surface of the screw in order thereby to rotate along with the screw so that liquid that is supplied via the conduit is uniformly supplied to the matter that passes through the screw compressor; wherein the casing of the screw compressor is a water-tight casing, which is impervious to liquid in an entire area between the inlet end and the outlet end so that the liquid that is supplied to the matter that passes through the screw compressor is pressed axially backwards through the screw compressor towards the inlet end of the screw compressor and wherein the screw compressor is arranged so that the liquid is supplied to the matter only when the matter has reached a dry content of at least 35%.