Patent GB-306537-A (GB)
Title: Improvement in automatic control system for gas-making apparatus
IPC: C10J3/24
Filed: 1929-02-09
Abstract: 306,537. Western Gas Construction Co., (Assignees of Barr, W. A.). Feb. 23, 1928, [Convention date]. Producers. - Apparatus for automatically controlling the operation of water-gas plant, and for coordinating the working of two or more such plants, comprises mechanism for varying the length of the cycle in each unit, and for interrupting and resuming the operation of each unit in uniform sequence and at variable intervals. A water-gas generator 1, Fig. 1, carburettor 2, and superheater 3 are provided with the usual change-over valves each of which is operated by a hydraulic cylinder, the oil or fluid supply to which is controlled by a master cylinder 61 and timer 62. For example, the hot gas outlet valve 10, operated by a lever 12 which is connected by a rod 51 with a valve 46 which directs the steam supply from pipe 44 to the top or bottom of the generator, is actuated by a hydraulic cylinder 36 connected by pipes 37, 38 to the lower and upper parts of the cylinder 61 which has a pressure conduit 66 and drain conduit 67. A piston valve 63 when in its upper position allows the fluid to pass from conduit 66 through an annular fluid space 68 and pipe 38 to raise the piston in cylinder 36, the fluid being exhausted by pipe 37 to the outlet 67. When the piston valve 63 is lowered, the pipe 37 is connected to the pressure conduit 66 and the pipe 38 to the exhaust conduit 67, the piston in cylinder 36 being depressed and valves 10 and 46 changed over. The other valves in the plant are changed over simultaneously in a similar manner. The shaft 70 of the piston valve 63 extends upwards and carries a piston 80, Fig. 2, adapted to be moved up or down a cylinder 74 by fluid pressure. Rigidly attached to the shaft 70 are two hollow stems 86, 87, the former being closed at the bottom and the latter open, these stems passing through sleeve-like housings 88, 89. 110 is a hydraulic reversing valve which supplies oil under pressure from a pump 126 to above or below the piston 80 and releases the oil from the exhaust side of the piston. The hollow stems 86, 87 act somewhat as dash-pots to control the movement of the piston 80, by being provided with holes 92, 93 opening into grooves 94, 95 which register in turn with a series of ports 100, 101 provided with needle valves 102, 103. The function of the area of the ports 100, 101 is to control the rate of travel of the stems 86, 87 and piston 80. During an up-stroke oil from the pump 126 passes through conduits 127 and 136 to the lower part 81 of the cylinder 74, forcing the piston upwards, the oil in the upper part 82 flowing through stem 87, ports 93, groove, 95 and escaping through ports 101 at a rate controlled by the setting of the needle valves, the oil then flowing through passage 99, conduit 147, valve 110 and conduit 144 to the low-pressure side of the pump 126. The oil in stem 86 and cylinder 90 escapes through conduit 134 to the high-pressure zone of valve 110 as conduit 146 is sealed in this valve. When the piston 80 reaches the top of its stroke an arm 160 coacts with a collar 158 on a rod 153 actuating a change-over pilot valve 150 which reverses the action of valve 110 causing the oil under pressure to be supplied to above the piston 80 which travels downwards at a rate controlled by the area of the ports 100, in a manner similar to that described in connection with the passage of oil through the ports 101. If one of these ports is blocked so that the oil cannot escape from the high-pressure to the low-pressure side, it is evident that the piston will remain stationary until oil can be released. One of the ports 100 is replaced by a conduit 200 having a valve 201, actuation of which stops or allows movement of the piston 80 by controlling the oil flow from the inside of the stem 86 to the release pipe 146. When a number of water-gas sets are being worked together, the valve 201 of each set is automatically actuated in predetermined sequence by a central control device 210, Fig. 3, adapted to open solenoidoperated valves 201 of a number of automatic; control devices 62. A constant-speed shaft 213, Fig. 4, drives a shaft 215 having an arm 216 carrying carbon brushes 220, 221 which bear against metal contacts flush with a non-conducting face 222, one brush 221 being movable in a slot in the arm 216. The brush 220 remains in contact with an annular ring 226 and the other brush may be adjusted radially to contact with each of a series of three concentric contacts corresponding with 6, 5 or 4 sets of water-gas plant. In the drawings, Figs. 3 and 6, five sets are being controlled so that five out of six jumpers 271 - - 276 are inserted in their respective jacks. To take one circuit, the current flows from main 230 to line 232, annular contact 226, brushes 220, 221, contact 251, line 291, jack 281, plug 271, line 301, coil of relay 311, and line 321 to return main 231. Relay 311 closes its contact element and current flows through line 341 and the solenoid valve 201 which is thereby opened. As the arm 216 rotates, each valve 201 is opened, starting a new " run " period at equal intervals of time. The length of the cycles may be varied by means of reduction gears 361 - - 365 which vary the speed of the shaft 215 and are brought into engagement therewith by a swinging arm 367.