Abstract: An apparatus for precipitating and separating a material in a solid form from a gaseous mixture. The substance which is settling in solid form can be very simply prevented from accumulating near the inlet by providing at least one channel with at least one controllable bypass.

Abstract: Apparatus for separating a sublimation product from a gas which contains this product in the form of vapor, 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 casi