GB1460908A - Apparatus for producing liquid fog or mist - Google Patents

Abstract

1460908 Preventing leakages in pipes BRITISH GAS CORP 15 Nov 1974 [22 Nov 1973] 54311/73 Heading F2P [Also in Division B2] A fog or mist producing apparatus for use to prevent or reduce gas-leaks in gas mains, comprises a calibrated, liquid-level sight-glass 4 connected in a first of three positions of a valve 3 to a liquid-reservoir 1 and a constant-level tank 2, so that the liquid is fed by syphoning action to nozzles 8 atomizing the liquid in a fogchamber 9, the sight-glass being isolated from the reservoir 1 but connected to the constantlevel tank 2 in the second position of the valve so that as the fog is produced in the chamber 9, the rate of drop of the liquid level in the sightglass gives an indication of the rate of consumption of the liquid by the apparatus. A high pressure gas flowing through a regulator 17, a plurality of valves 19 and the nozzles 8 atomizes the liquid and also helps in removing large droplets on striking a plate 10. A sweep gas supplied below the plate 10 sweeps the fog out of the chamber into a separator 12 wherein, by a cyclonic action, the remaining large droplets are removed, and the final fog fed to a gas main 16 contains droplets having a diameter less than 10 microns. The fine fog carried along the main by the gas deposits on to the jute in the joints and the consequential swelling of the jute prevents or reduces gas leaks.