Patent GB-426933-A (GB)
Title: Improvements in or relating to gasometers
IPC: F17B1/14
Filed: 1934-12-20
Abstract: 426,933. Gas holders. SCHAFER, B., Phillipsburg, Landhaus Frieda, Germany. Dec. 20, 1934, Nos. 36575, 36576, and 36577. Convention dates, Dec. 20, 1933, March 9, 1934, and Oct. 22, 1934. [Class 54] In order to prevent the formation of explosive mixtures above the pistons or bells of dry gas holders or above or around the lifts of wet gas holders a funnel-shaped roof 4 is provided above the holder leaving for the escape of gases leaking past the piston &c., an opening 6 having an area at least equal to the internal cross sectional area of the holder. In the dry gas holder construction shown in Fig. 1 the external columns 1 are extended to support the roof 4 which extends far beyond the gas holder wall and conveys falling rain or snow to a drain pipe 9 secured in a discharge pit 10 in the holder base 16. The holder piston 7 is bolted to flanges 12, 13 on a guide member 11 which is slidable on the drain pipe 9. The guide member 11 is widened at the top to form a cup 14 to receive sealing oil flowing down the drain pipe from a cup 19 secured to the flanges 17, 18 connecting the roof to the drain pipe. From the cup 14 the oil can pass to the peripheral packing 7<1> of the piston. When the piston reaches its highest position the engagement of the member 11 with the flange 18 may complete a circuit operating a valve to close the gas supply pipe leading to the holder and open a pipe leading to another holder. The roof 4 is fitted with a manhole door 20, a strainer 21, and a snow-thawing device such as an electric heater. Doors 22 sealed by rubber packing strips in the outside wall provide for access to the piston and those above the piston may be removed, when danger arises, to improve the ventilation. When in its lowest position the piston 7 rests on the base 16 and all gas is expelled from the holder. In a modification the base 16 is supported above the foundation on arched lattice girders or light supports and the bottom of the drain pipe 9 is secured to a cup on the base, this cup being provided with lateral branches for the attachment of the gas supply and discharge pipes. Radial grooves may be provided in the base leading the sealing oil running down the gas-holder walls to the cup. The bottom of the piston may be flat, an inverted peripheral groove preventing the sealing liquid from flowing inwards. Fig. 5 shows a further modification in which the base 31 and if desired, the piston 7 may be lowered relatively to the holder on to a carriage 321 by a hydraulic or mechanical lifting device 33 and the carriage may then be moved on rails 36 away from the holder. The holder is mounted in a raised platform 35. In this construction the pipe 9 is led to the outside of the holder and the piston 7 is formed with a curved rim 37 so that an annular channel 38 is left between the piston and the base when the piston is in its lowest position. The gas inlet and discharge pipes 39, 40 open into this channel. The base 31 may be formed with a peripheral sealing trough 30 engaging the bottom of the holder wall or may be provided at its edge with packing allowing it to be raised above the gas pipes 39, 40 if the pipes are damaged. An inverted conical screen may be arranged around the lower part of the holder to divert flames from the holder if escaping gas become ignited. The underside of the screen may be covered with asbestos or other heat insulating material. Fig. 8 shows a multiple lift water-sealed gas holder in which the drain pipe 9 of the roof 4 forms a guide for the bell 43. The bottom 44 of the holder rises above the water level in the sealing trough so that the water cannot reach the oil seal of the guide member 11 or the cup 15 to which the gas pipes 39, 40 are attached. The gas holder may or may not have an enclosing casing. The invention can also be applied to waterless gas holders of the type in which a bell is movable relatively to a stationary piston.