GB1048056A - Improvements in or relating to low pressure steam drying method and machine - Google Patents

Abstract

1,048,056. Tumbler driers; tubular apparatus for heating air. INTERNATIONAL DRYERCORPORATION. Nov. 19, 1964, No.47088/64. Headings F4G and F4S. In a tumbler drier, air is passed into, through and out of the horizontally mounted, perforated drum 20, Fig. 1, along a path defined by baffle walls and is heated prior to entry to the drum in a heat-exchanger 50 utilizing low-pressure steam at 15 p.s.i.g. or less, and the heatexchange is effected by restricting the area of the path in a hopper-shaped heat-exchange support 76 so as to cause eddy currents in the heatexchanger. The air is drawn through the heatexchanger and support 76 and then through vertical deflector plates 92 to an opening 93 in a baffle 94 surrounding and closely conforming in shape to the drum for passage through the drum and exit through a discharge opening 96 in the baffle under the influence of a suction fan in the form of a backward wave impeller 40. The air is finally exhausted via a resilient lint trap which, on cessation of the fan, flexes to allow the lint to fall to the lower inner floor of the drier casing for removal by hand. The heat-exchanger 50, Fig. 3, comprises a frame 52 in which the steam conduits 56 are formed with fins 70 and have no more than four parallel horizontal tube sections joined by loops 58, 60 and are connected in parallel by an inlet and outlet header 62, 64; and the fins are directed at right-angles to the inclined walls of the hopper-shaped support 76 to deflect a portion of air thereagainst to aid the heat-exchange process.