摘要 |
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. |