Apparatus for separating a sublimation product from a gas

Apparatus for separating sublimation product from a gas which contains this product in the form of vapour, comprising an elongate substantially horizontal casing having a gas inlet near one end and a gas outlet near the other end so that gas flows longitudinally through the casing;

• heat exchange means cooperating with the exterior of the wall of the casing for cooling said wall below the sublimation temperature during the subliming process, means for assuring that an open channel for gas flow is maintained during the subliming process, said means comprising at least one permanently heated, elongate, rod-shaped element fitted eccentrically in the casing, said element extending in the same direction as the casing and being placed in the upper part of the casing, said heating element being manufactured of a material having good heat-conducting properties and projecting into the casing through a wall portion over part of the length of the heating element so that heat can be supplied thereto from outside the casing, the end of the heating element which is located within the casing being supported on a baffle structure and said heating element comprising an inner tube disposed coaxially within an outer tube with an annular space therebetween, said outer tube being closed at the end located within the casing and said inner tube being open at the end located within the casing so that a heating medium can be supplied through the annular space between the tubes.