Abstract: In a power plant, for example of PFBC type, with a cooler for cooling of ashes originating in a fluidized bed, the cooler comprises a cylinder with a transport screw which transports the ashes through the cylinder. The transport screw has a tubular shaft which is transversed by cooling water. The cylinder may be air or water-cooled. At the bottom of the cylinder one or more fluidization devices are provided, which maintain the ashes in the cylinder in fluidized condition, so as to obtain good contact and effective heat transfer to cooling surfaces of the shaft and the cylinder. The fluidization also reduces the propensity of the ash to form a heat-insulating layer on the inside of the cylinder which reduces the cooling capacity.

Abstract: In a screw conveyor the conveyor screw is arranged in a casing where there is at least one support fastened to the casing between the ends of the conveyor screw, the conveyor screw being mounted in the support via a bearing which is sealed by a seal. Included in the seal there are two sealing devices which are unrotatably but axially displaceably mounted on the screw shaft, and which are urged axially from opposite directions to press with a respective sealing portion against a corresponding sealing portion on the support. The sealing portions are situated radially outside the bearing. Each sealing device at its end facing away from the support engages against a sealing element, which in turn connects to the screw shaft.