| 主权项 |
1. A device for calibrating membrane tubes which are extrudable by an extrusion die, comprising:
a ring having an interior wall, along which the extruded membrane tube can be guided in a transport direction (z), a cooling liquid source device with which a cooling liquid can be provided, said cooling liquid being conveyed to between the interior wall and the extruded membrane tube, wherein the ring includes at least one open chamber in a region where the extruded membrane tube exits the ring, wherein at least one opening of the at least one open chamber is facing the extruded membrane tube and is sealed by at least one permeable element, and wherein a vacuum can be applied to the at least one open chamber, a ring-shaped body provided downstream of an upper edge and upstream of a lower edge of the at least one open chamber in the transport direction (z) of the extruded membrane tube, said ring-shaped body including a surface facing the extruded membrane tube which is inclined relative to an exterior surface of the extruded membrane tube, a fluid pressurized with overpressure which can be applied to the ring-shaped body, the surface of the ring-shaped body facing the extruded membrane tube being permeable for said fluid, with the surface being covered with the at least one permeable element, and one part of a resulting fluid flow flowing against the transport direction (z) because of the vacuum in the at least one open chamber. |
