Combined fly ash and bottom ash handling system

摘要

902,676. Fluid-pressure servomotor-control systems. ALLEN SHERMAN HOFF CO. April 13, 1960, No. 13209/60. Class 135. [Also in Group XII] The delivery of ash to a sump 5 from a furnace ash pit is controlled in accordance with the water level in the sump by a differential pressure sensing device 75, a pilot valve 100 and a diaphragm device 33, Fig. 2, controlling a valve 32 in the supply line for high-pressure water to entrain the ash for delivery to the sump 5 through pipe 6. The normal level of the water in the sump 5 is maintained above the level of a pipe 87 connected to one side of the differential pressure device 75 by a water supply pipe 57 with a level controlled valve. The other side of the differential pressure device 75 is connected to a pipe 89 opening above' the water level in sump 5. When the water level in sump 5 falls due to the removal of ash and water by a pump 48, the reduction of the hydrostatic pressure in line 87 causes an increase in the pressure above the diaphragm of pilot valve 100, to. open the valve and allow fluid to flow from a supply pipe 101 through pipe 105 to device 33 to open valve 32. A rise in the water level in sump 5 causes an increase in the pressure difference between lines 87 and 89, and a decrease in the pressure within chamber 84 of the differential pressure device 75, so that liquid flows from valve 100 through pipes 102, 103 and 104 to the space below the diaphragm of valve 100 to close it and cut-off the supply of fluid to line 105, thus closing the water supply valve 32. The differential pressure arrangement enables the water.. and bottom ash supply to be controlled independently of variations in the pressure in upper part of the sump 5 caused by the operation of the cyclone separator 60 for the fly ash delivered from a pipe 11.