This system is consist of one single screw conveyor on the top + vertical round hopper + bottom twin screw conveyor. The single screw conveyor is used to discharged dust. The twin screw conveyor is used to feeding materials cyclically. Among of them,discharged screw conveyor is at the top of hopper. The cyclically twin screw conveyor is at the bottom of hopper. On the top of hopper,there is a separator with slide gate valve. The expansion joints are connected the slide gate valve and the inlet of hopper. The outlet of discharged screw conveyor is connected to the pneumatic conveying system.There also are some level switch inside the hopper,one the the high level switch,the other one is the low level switch.
When the hopper is started to operate, it is connected with the separator. The fuel gas temperature reaches about 320～380℃,negative pressure is -500～-2500Pa. The cyclical dust is rotated and dropped into hopper,then transported by twin screw conveyors and returned materials evenly to the desulfurization tower to make desulfurization . Use the frequency inverter to control the flowrate of screw conveyor .Under the automatic feeding condition,the stop and start of bottom twin screw conveyor are controlled by the low level switch.www.wxconveyor.com