GB1442829A - Selfcontained mobile bituminous concrete mixing apparatus - Google Patents

Abstract

1442829 Drying aggregate H M ZIMMERMAN 6 Sept 1973 [14 Sept 1972] 41919/73 Heading F4G [Also in Divisions B1 and E1] A self-contained, continuously operable and mobile bituminous concrete mixing apparatus comprises an elongate mobile frame 20, Fig. 1, a storage compartment 24, Fig. 3, disposed on the frame for storing aggregate and which may have a plurality of separate chambers 40, 42 for storing different aggregates, a separate compartment 26 for storing liquid bitumen, an elongate hollow rotatable drum 34 and a burner 92 for heating and drying aggregate in the drum which has agitating vanes 80 for moving a flow of aggregate through the drum from the front to the rear during rotation of the drum. Conveyer means 30, 32 transports a flow of aggregates from compartment 24 and into the front end of the drum and receiving means 110, 112 adjacent the rear end of the drum receives the heated and dried aggregate from the drum and discharges it into mixing means 116, 118. Liquid bitumen is automatically discharged and metered into the mixing means by means 120-122. The arrangement of the apparatus is such that the flow-path of aggregates from storage compartment 24 to mixing means 116, 118 extends along substantially straight lines. In the particular embodiment, the aggregate is conveyed out of chambers 40, 42 by substantially horizontal conveyer 30 passing beneath the open bottom sides of the chambers and through metering gates 48, 50 controllable by hand wheels 60, 62, Fig. 5. Bucket conveyer 32 receives the aggregate and transports it to auger 70 and thence it is passed into drum 34. Burner 92 is attached to blower 96 to provide forced hot air in the drum whence it is extracted by blowers 106, Fig. 5, through channels and into the chambers 40, 42 for pre-drying the aggregate and removing dust from the drum. Dried aggregate moves down the inclined drum and falls into hopper 36, Fig. 3, whence it is fed by rotary conveyer 112 through metering gate 110, Fig. 7, into funnel 116 of the mixing means where it is joined by bitumen from pipe 120. The mixer is an auger-type pug mill 118. The aggregate and bitumen are synchonized to be fed together by mechanism 124-132 which is actuated by the weight of aggregate in the hopper to switch on motor 130 of conveyor 112 and pump 122 for the bitumen. The mixture drops from the mixing means into a spreading device 38 for spreading it onto the road (see Division E1)