1) barrel washer 2) drum washer a device for cleaning raw coal, comprising a cylinder rotating slowly about an axis slightly inclined to the horizontal, into which the raw coal, with a current of water or in suspension, is fed near its upper end GRM: n. (1,2) Note: the clean coal is carried by the water or suspension to the lower end of the cylinder over a scroll that conveys the reject to the upper end of the cylinder References: SEEcoal cleaning