SCREW VENT FOR DEVOLATILIZER

摘要

A vent for a devolatilizer includes a vent opening (20) in the cage (10) of the devolatilizer and a vent duct (22) which communicates with the vent opening. Vapour escapes into the cylindrical vent chamber (24) in the vent duct. The chamber is cleaned by a vent screw which is rotated in the chamber and includes a screw body (26) of minimal diameter and a helical screw flight portion (28) of a pitch which is sufficiently large such that the velocity of the vapour leaving the cage through the vent duct is maintained below a predetermined maximum vapour velocity. This maximum vapour velocity is set such that the amount of fine material which is entrained in the escaping vapour is minimized. A vapour outlet (48) is connected to the vent chamber for extracting vapour from the chamber so that it may be recycled or disposed of.