Screw press for separation of liquid from bulk materials

A screw press liquid separator comprising:

• an elongated housing having an inlet end and a discharge end;
• a perforated screw cradle disposed within the housing and having an inlet portion having a material inlet disposed at the inlet end of the housing and a compression portion;
• a screw defining an input end and a discharge end formed on a shaft and disposed within the screw cradle, a first portion of the screw extending from the input end of the screw and a second portion of the screw extending to the discharge end of the screw and completely surrounded by the compression portion of the screw cradle, a first portion of the shaft having a first diameter extending from the input end to the discharge end of the screw, a second portion of the shaft disposed within the compression portion of the screw cradle and extending past the discharge end of the screw and having a second diameter larger than the first diameter, and a transition portion of the shaft disposed between the first and second portions having a diameter tapering from the second diameter to the first diameter;
• a first discharge guide extending from a top portion of the discharge end of the housing;
• a second discharge guide extending from a bottom portion of the discharge end of the housing;
• a pair of opposing discharge doors pivotally mounted to the discharge end of the housing and movable within a volume defined by the first and second discharge guides, the discharge doors close at the discharge end of the housing;
• a motor rotatably coupled to the shaft;
• and
• a plurality of paddles affixed to and radially extending from the shaft at a position beyond an arc defined by pivotal motion of the discharge doors.