GB1314560A - Coke ovens - Google Patents

Abstract

1314560 Reversing systems for coke ovens KOPPERS CO Inc 17 Dec 1970 [17 Dec 1969] 60089/70 Heading F4K An hydraulically operated reversing system 11 for a regenerative coke oven (not shown) comprises a first valve (not shown) for directing the fuel gas flow to either of a first or second group of coke oven heating flues (not shown), and a second valve (not shown) for directing air to the same group and hot waste gases from the other group. The valves are operated by respective double piston cylinder assemblies 37, 39, one piston of each cylinder being fixed, the other piston and the cylinder being free to move. To start a reversal a timer (36, Fig. 9, not shown) opens solenoid valve 21 to allow oil from pressurized accumulator 13 to move pistoncylinder assembly 37 and the associated fuel gas valve, from an extreme position in which fuel gas is supplied to one of the flue groups to a neutral mid-point position in which fuel gas is supplied to neither group. During this movement a cam (63, Fig. 2, not shown) operatively connected by linkage 61, 59, 57 to assembly 37 opens valve 31 to allow oil from accumulator 13 to move piston-cylinder assembly 39 and the associated air and waste gas valve, from one extreme position to another, to reverse the air and gas flows in the first and second flue groups. During this movement a cam likewise linked to assembly 39 opens valve 25 so allowing a further flow of oil to assembly 37 to move it and the fuel gas valve from the neutral position to the other extreme position from that it first occupied to reverse the original fuel gas flow. On subsequent actuation of solenoid valve 23 by the timer a similar reverse sequence is followed to restore the system to its initial state. Preferably a second timer and associated oil flow control valves are provided so that the assembly 39 when moving from one extreme position to another stops at a neutral midpoint position for a predetermined period during which no air is supplied to either flue group. A mechanical interlock system (Figs, 4 to 8, not shown) is provided. This prevents assembly 39 from operating unless assembly 37 and its associated fuel gas valve are in the neutral midpoint position, whereas assembly 37 can always be moved to its neutral mid-point position to stop the fuel gas flow, but cannot be moved past it to reverse the fuel gas flow until the assembly 39 has completed its movement between its respective extreme positions. Safety valves 27, 29, 33, 35 close to shut off the fuel gas supply if the pressure in accumulator 13 fails. Valves 21 and 23 may be actuated by a selector switch (not shown) in an emergency to move assemblies 37 and 39 to their neutral mid-point positions to shut off all fuel and air flows to the flues until the valves 21 and 23 have been manually reset.