Anfahrventil für einen Extruder, insbesondere einen Zweischneckenextruder

摘要

A valve housing(10) attaches directly or indirectly to an extruder barrel and has a first flow opening(12) aligned with the screw chamber. The cross-section of the first flow opening is large enough to allow extraction of the extruder screw through the opening. A valve bolt(20) is arranged in the valve housing with its axis perpendicular to the melt flow and has a second flow opening(22) aligned with the first. The cross-section of the second flow opening is also large enough to allow screw extraction. Adjustment of the valve bolt is possible in the valve housing. Flow openings for a twin screw extruder form spectacle-shaped bores. A groove-like axial cut-out(24) is radially offset from the second flow opening at the outer periphery of the valve bolt. An inlet(16) and an exit channel of the first flow opening(12) connect with the second flow opening in the valve bolt(20). The inlet channel(16) and a start up channel are connected by the groove shaped cut-out in the valve bolt. A center axis of an extruder screw or both axes of twin screws intersect the center axis of the valve bolt. Valve bolt movement is by a drive unit. The valve may be integrated in the extruder barrel.