Patent GB-400864-A (GB)
Title: Improvements relating to piston-type gasholders
IPC: H05B6/18
Filed: 1933-05-01
Abstract: 400,864. Gas holders. BAMAGMEGUIN AKT.-GES., 10, Reuchlinstrasse, Berlin. May 1, 1933, Nos. 12665, 12666, and 12667. Convention dates, Oct. 7, 1932, Oct. 29, 1932, and Nov. 29, 1932. [Class 54.] A gas-holder piston is provided with two superimposed packing pads filled with liquid under pressure, one being normally in use and the other forming a reserve packing which is brought into use automatically should the first become damaged. Fig. 1 shows one construction in which liquid from a main tank 5 can pass through a pipe 6 fitted with a throttle 7 to one or more auxiliary tanks 8 communicating through a pipe 9 with packing 2. A float valve closing the pipe 6 may be provided to limit the liquid level in the tank 8. If the packing 2 fails liquid escapes from the tank 8 faster than it can enter through the throttle 7 and the liquid level falls to such an extent as to cause a float 13 to operate a valve 18 to shut off the pipe 9 and to open a valve 15 to allow the liquid to pass through a pipe 11 to a reserve packing 3. A spring-operated pawl 20 holds the float in its lowered position when the liquid level rises in the tank 8. In order to maintain uniformity of pressure at the working and reserve packings the auxiliary tanks may consist of a number of float chambers at different levels the floats being arranged to act in sequence. Fig. 4 shows another construction in which compartments 43, 44 in the auxiliary tanks are connected by pipes 47, 48 controlled by float-valves 50 to separate compartments in a main tank and are fitted with valves 51, 52 controlling the liquid flow to the packings. The valves 51, 52 are each operable by a weighted lever 54 which can be held in the raised position by a pawl 57 on a lever adapted for engagement by a float 61 in the opposite compartment. If the working packing becomes damaged the liquid level in the compartment 44 supplying it will fall when the compartment of the main tank connected to the pipe 47 becomes empty and the float 61 will operate the pawl 57 to release the lever 54 and open the valve 51. In a modification the valves 51, 52 are operated by a single weighted lever, one valve being maintained open when the other is closed. Fig. 7 shows another construction in which the liquid can pass from a main tank 81 through adjustable throttle valves 84, 85 to the opposite sides of a piston 87 in a cylinder 86 connected by pipes 90, 91 to the packings 2, 3. The differential pressure caused when the packing 2 becomes damaged operates the piston to shut off the pipe 90 and open the pipe 91. Fig. 8 shows a further construction in which the pipes 90, 91 leading from the liquid tank to the packings 2, 3 are controlled by slotted bells 100, 101 which are suspended from a loaded lever 104 and dip into a mercury layer 102. Should the working packing become damaged the slots 107 in the bell 100 are too small to allow sufficient liquid to pass into the pipe 90 and a downward pressure on the bell 100 results. The lever 104 is consequently turned on its pivot to raise the bell 101 and bring the reserve packing into operation.