Abstract: Air-cooling apparatus for a heat-exchange jacket which surrounds the outside of a vertical extruder barrel. The apparatus comprises a hood which surrounds the jacket and includes a plenum chamber at one side of the jacket, an outlet opening at the opposite side of the jacket and a restricted inlet opening between the jacket and plenum chamber wherein the hood provides a through-passage between the inlet and outlet openings. Means are provided for forcing air into the plenum chamber to create a super-atmospheric pressure therein and provide an air flow through the through-passage. The hood also includes an outlet chamber adjacent the outlet opening which has the same vertical cross-sectional configuration as the plenum chamber to provide a balanced air draft condition on opposite sides of the heat-exchange jacket.

Abstract: Screw removing apparatus for vertical extruders wherein the screw is removable through the bottom of the extruder barrel, the apparatus including an adaptor for attaching to the upper end of the screw, a winch for fastening to the adaptor and which includes a yieldable locking means which enables the winch to support the weight of the screw and which yields upon application of a predetermined downward force to the adaptor which is sufficient to overcome the yieldable locking means.