Patent ID: 6363625
Filing Date: 2002-04-02
Classification: E01C

Abstract:
A drying and mixing plant for mixing material with an additive comprising:(a) an inner drum having an input end for receiving material and an output end for discharging material, said inner drum being tapered such that the diameter of said input end is smaller than the diameter of said output end; (b) an outer drum concentric to said inner drum and attached to said inner drum so as to rotate in concert with said inner drum, said attachment such that there is an open chamber between said inner and outer drums, the resulting inner and outer drum assembly rotatably mounted on a frame so that the axis of said drums is approximately horizontal; (c) a drive mechanism adapted to rotate said drum assembly; (d) said outer drum having an input end for receiving material from said output end of the inner drum, and an output end at the opposite end thereof for discharging said material, said outer drum being tapered such that the diameter of said input end is smaller than the diameter of said output end; (e) a first shroud enclosing said input end of the outer drum; (f) a second shroud operatively connected to said chamber at the output end of the outer drum, said second shroud directing exhaust air to an exhaust air duct, and said second shroud further directing the mixed material to a material outlet; (g) a burner and blower directing a stream of hot air into said input end of the inner drum, said hot air thereby moving through said inner drum, thence through said chamber and thence through said exhaust air duct; (h) an additive material input for introducing an additive material into said material after said material leaves said output end of the inner drum; (i) impellers attached to the inner surfaces of said inner and outer drums for lifting said material towards the top of said drums and dropping same into said air stream, and for moving said material through said drums.