Patent GB-774761-A (GB)
Title: Improvements in apparatus for controlling the supply of flushing liquid to the gas collecting mains of coke oven batteries
IPC: C10B27/06
Filed: 1955-09-09
Abstract: 774,761. Gas collecting mains. KOPPERS GES., H. Sept. 9, 1955 [Nov. 24, 1954], No. 25870/55. Addition to 700,259. Class 55 (2). [Also in Group XXIX] Apparatus for controlling the supply of flushing liquid to a gas-collecting main comprises a vertically disposed double-acting piston in a cylinder 1, the piston having a pair of opposed and connected working surfaces 8 and 13 and, between the. working surfaces, an annular space 50 communicating via a cylindrical extension 15 from the surface 13, a cylindrical guide 41 and a pipe 19 with a drain 61, the working surface 13 communicating with a conduit 28 for supply of ammoniacal liquor under pressure and the working surface 8 communicating with a conduit 12 for a reserve of flushing liquid, e.g. town's water, under pressure so that the piston is responsive to the difference in pressure between the ammoniacal liquor and the reserve flushing liquid supply and moves under the influence of the liquid at the preponderating pressure to a position in which it permits such liquid to flow through an outlet 26 connected with the gas-collecting main. The working surface 8 has an extension 43 running at its upper end into a cylindrical guide 45 secured to the cylinder 1, a projection 51 on the extension 43 serving to limit the upward movement of the piston. The cylinder is provided with slots 21 and 23 and is surrounded at these points by annular chambers 14 and 24 which are connected respectively by connections 11 and 25 to the conduit 12 for reserve flushing liquid and to the conduit 26 for the supply of flushing liquid to the collecting main. The areas of the working surfaces 8 and 13 are chosen so that under normal working the pressure of ammoniacal liquor from pipe 28 and passing into the cylinder 1 by a connection 37 on the surface 13 is sufficient to hold the piston in the position shown, when ammoniacal liquor can pass via slots 23, annular chamber 24, connection 25 and conduit 26 to the collecting main. Any ammoniacal liquor leaking past the surface 13 will pass via the space 50 to the drain 61. Similarly, any reserve flushing liquid leaking past the surface 8 will also pass to the drain 61. In the event of the supply of ammoniacal liquor failing the pressure of the reserve flushing liquid acting on the surface 8 will move the piston downwards until the surface 8 is just below the slots 23 when reserve flushing liquid from conduit 12 will flow to the conduit 26. The conduit 12 is provided with a non-return valve 48 and a vacuum relief valve 49. To facilitate repairs to the supply of ammoniacal liquor the piston may be held positively in the lower position by allowing the pressure of the reserve flushing liquid to act on the whole of the surface 8. In this event reserve flushing liquid is admitted to the inside of the extension 43 via connecton 67, 3-way valve 68 and pipe 65. During normal working however the valve 68 is in the position shown and any air or liquid in the extension 43 can pass to the drain 61 via pipe 65<SP>1</SP> during upward movement of the piston and air can be admitted to the extension 43 during downward movement of the piston. A connection 66 from connection 37 and a 3-way valve 69 which may be put into communication with the drain 61 enables the piston to be moved up and down without restraint when valves 57 and 58 are closed. In normal working however the 3-way valve 69 is set in the position shown, placing connection 66 in communication with a pipe 70 leading to a pressure-sensitive mechanism 71 adapted to operate the 3-way valve 68. Thus, when the pressure of ammoniacal liquor in connection 37 falls the 3;way valve 68 is operated to bring connection 67 into communication with the pipe 65 and thus move the piston quickly and bring the reserve flushing liquid rapidly into use. The piston may be manually controlled through the rod 29.