GB1106082A - An improved method of and means of handling particulate material such as dust - Google Patents

Abstract

1,106,082. Pneumatic conveyers. BABCOCK & WILCOX Ltd. 22 March, 1965 [20 March, 1964], No. 12026/64. Heading B8A. An apparatus for discharging dust from a container 1 into a line 8 leading to a dust separator and slurry forming apparatus comprises coaxial pressurized air nozzles 10, 11 discharging into the line 8 at the base of the container 1 under the control of pneumatic valves 14, 15, nozzles 17 for discharging pressurized air into the chamber 1 under control of a pneumatic valve 20 and a pneumatically controlled sliding flap 27 controlling the flow of dust from a hopper 21 into the container 1. The flap 27 and valves 14, 20 together with a valve 30 controlling a dust agitating air nozzle 29 in the hopper 21, are connected into a common pneumatic system 33, 34 under the control of a timer 31 for cyclic operation. The valve 15 controlling the overall air flow is operated by an independent pneumatic system 39, 40 responsive to the level of dust in the hopper 21. In operation with the flap 27 open, valves 30 and 14 open and valve 20 shut, the dust gravitates into the line 8 where it is fluidized by air from nozzles 10 and 11, and the dust level in the container 1 steadily rises. At a predetermined time interval the timer 31 causes closure of flap 27 and valves 14 and 30 and opening of valve 20 whereupon the space above the-dust in the container 1 is pressurized to aid discharge therefrom, the discharged dust being fluidized by air issuing from nozzle 11 only. This cycle is then repeated. A safety valve 43 in the container operates in the event of a dust blockage and a pressure gauge may be incorporated to give warning and/or shut off valve 15 prior to the valve 43 operating. In a modification, a dust level indicator 44 in the container 1 causes the flap 27 and valves 14 and 30 to re-open, and valve 20 to re-close when the dust level drops sufficiently. In another modification the flap and valves are controlled by a pressure gauge 45 in the line 8 instead of by the timer 31. In the embodiment, Fig. 2 (not shown), the sliding flap is replaced by a pivoted flap controlled by the air pressure in the container.