GB1174068A - Furnace Top Charging Equipment - Google Patents

Abstract

1,174,068. Charging blast furnaces. ISHIKAWAJIMA-HARIMA JUKOGYO K.K. 18 May, 1967 [8 Nov., 1966], No. 23172/67. Heading F4B. Blast furnace top charging equipment, includes two raw materials storage hoppers 6, 7 into which charging material is alternately fed through bifurcated shoot 3 from conveyer 1 in dependence upon changeover dampers 2. Whilst B side hopper 7, is being filled with its gate 9 and lower gas seal valve 11 closed, and its upper gas seal valve 5 and exhaust valves 28 in exhaust line 17 to atmosphere open, the A side hopper 6, which has its upper gas seal valve 4 and exhaust valves 27 closed, and is maintained at furnace top pressure through connection 19<SP>1</SP>, the equalizer valves 24 being open; discharges material into bell hopper 14 through revolving shoot 13. When the hopper 6 is completely discharged, its gate valve 8, lower gas seal valve 10, and furnace top pressure equalizer valves 24 close, and its exhaust valves 27 and upper gas seal valve 4 open and it is then recharged from conveyer 1 whilst hopper 7 discharges its contents into bell hopper 14 through revolving shoot 13. The pressure in hopper 7 is brought up to the furnace top pressure in two stages, prior to the material discharge, after its exhaust valves 28 and upper gas seal valve 5 have been closed, firstly by gas admitted through line 18 and valves 21, 23, and then with gas admitted through line 19<SP>11</SP> and valves 25. The bell hopper 14 then continues to be charged alternately from hoppers 6 and 7. After receiving a charge from both hoppers 6 and 7, bell hopper 14 discharges into the furnace during the period of changeover, whilst the lower gas seals 10, 11 of both raw material hoppers 6, 7 are still closed. During the discharge period of bell hopper 14, equalizer valves 26 in line 19, which normally maintain the bell hopper 14 at the furnace top pressure, are closed. It is stated to be known, Fig. 1, to feed material from a conveyer a by a bifurcated shoot b simultaneously into twin hoppers c having closed gates d and gas seal valves e, and then with the conveyer a stopped, to open the valves e and gates d to simultaneously discharge both hoppers e through revolving shoot g into small bell hopper h connected to atmosphere through open exhaust line l. After discharge, the gates d and valves e are closed, exhaust valves t in line l are closed, and small bell hopper h brought up to furnace top pressure in two stages, firstly with gas from line m with valves p and g opened, and then with gas through line n with valves r opened. Whilst hoppers c are being refilled, small bell valve i is opened to charge large bell hopper j, which is maintained at furnace top pressure through line n, valve s being opened. After every two charges from small bell hopper h, just prior to the next charge, large bell valve k is opened to discharge bell hopper j into the furnace. During this period the furnace top pressure equalizing valves s in the line n are closed.