DISSOLVED ACETYLENE_ AND ITS USES.
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A Description of a Visit to the Works of Allen-Liversidge, Ltd., and Notes on the Gas Cylinders, Blow-pipes, and Other Articles Made by Them.
FEW people realize the extent to which dissolved acetylene is eraplayed in the daily work of innumerable factories, but an inspection of one or other of the works of Allen-Liversidge, Ltd., whose head offices are at 106, Victoria. Street, London., S.W.1, will do much to convince the visitor that dissolved acetylene plays a great part in modern industry. The advantages of " Jaaving acetylene stored safely in cylinden of comparatively light weight And bulk are great. Even when perfectly generated, there are always present in the carbide itself certain impurities, which, during decomposition, produce ammonia, sulphuretted hydrogen, and phosphorized hydrogen. Such impurities' if not removed, tend to produce bad work. This is not the case, however, with. the pure acetylene used for filling Allen-Liversidge Qylinders, which has been thoroughly dried and purified before compression by special appliances in the company's works.
We recently visited the Lambeth works of the company, one of the many statiens where acetylene is produced.
At these fine works there are four batteries of generators and three gas holders. The purifier consist of fossil earth saturated with chromic acid, the earth being very porous and merely acting as a means for suspending the acid.. In order to test the purity of the gas before utilizing it a few drops of 10 per cent, solution of nitrate of silver are poured on to blotting paper and allowed almoat to dry. This blotting paper is held against a tap and the gas turned on, and if pure the paper remains white, . whereas impure gas torus the silver nitrate black.
The phosphorus ill acetylene ia very detrimental to welding work, as it makes the molten metal brittle and porous, and it is. therefore, essential that every trace of phosphorus should be removed.
The cylinders for containing the gas • are made of seamless solid-drawn steel -122 tube, filled with a special downy vegetable fibre called kapok, which is the seed hair found in the pods of a certain plant grown in India and elsewhere in the East. It is the lightest and most absorbent abre which has yet been discovered, the buoyancy of kapok in water being 35 as agaanst the 5 of cork.
Now, acetylene is aoluble, in various hydrocarbons, and particularly in that known as acetone, which will absorb approximately 25 times its volume of aoetylene gas for every atmosphere of pressure applied; the kapok in the cylinder is, therefore, more or less saturated with this solvent. The vegetable fibre itself does not absorb the gas, but its fibres are so minutely subdivided that the acetone and acetylene are thoroughly absorbed throughout the mass ; thus there can be no free pockets of gas or free solvent, and the latter can take up the maximum quantity of gas. The quantity of solvent used depends, of course, upon the size of the cylinder. These are made to hold from 6 to 300 cubic •feet.
Apart from the enormous amount of welding and cutting work which is done by the use of the oxy-aoetylene blow pipe, the gas is put to many other uses. It can be used with the utmost advantage for brazing, soldering, and leadburning, and it is, of course, used to a large extent for commercial vehicle lighting and also for flare-lights by public works authorities.
Apart from their filling works in Lam.. beth, the company have several other large works, at Clapham, Peckham, Battersea, and Camberwell in London ;at Belfast, Cardiff, Glasgow, and Newc-astle-ou Tyne, and at Sydney. and Melbourne in Australia..
Much of the work is being concentrated sa Clapham. Here they have a large assembly shop for blow-pipes and regulators, as well as a smithy and a testing shop for the blow-pipes ; the latter are scientifically examined, columns of mercury indicating the gas pressure.
The process of making the cylinders is a very interesting one, the small cylinders being made of welded-steel tube spun over at -the upper end, while in. the case of the bottom end this has a supporting piece, over which the sides are folded. The difficulty has been to obtain a cylinder of the requisite, dimensions in a section light enough to avoid prohibitive cost of transport, whilst being heavy enough to withstand a hydraulic test pressure of 1,000 lb. per square inch. Another type of cylinder is also made; in this caste the bottom is concave in stead of convex.
While at the works we examined Some of the latest productions. One of these is a high-pressure acetylene brazing blow, pipe, in with no oxygen is utilized. This pipe has an automatic air regulator and has a consumption of 30 litres per hour. The company have a very fine system of cylinder distribution and exchange. Cylinders may either be loaned or par chased outright, the price of the gas vary rag accordingly. Once a cylinder is pur chased, a full cylinder is given in ex
change for the empty one at the cost of the gas only, and this exchange can be effected in almost any part of the British isles, a useful little book, giving a list of these exchange stations, is being issued by the company. The latter have a fleet of about one dozen lorries in London, in addition to those working provincial districts. These are all used in their distribution . scheme. These vehicles are known as the AlIen-Liyersidge "Red Fleet" ; those based in London distribute daily around the London district, and also as far north as 13;rniingliam, and south to Southampton and Portsmouth, whilst east and west delivery covers a radius of about 40 miles. We have not the spate available co deal in detail with the numerous other interesting productionS; from the AlienLiversidge works, but we must certainly refer briefly to the well-equipped portable welding and cutting outfits the fine examples of cast aluminium head and tail lamps, and the Ralph patent automatic traffic warner—a most useful device, which should proveeminently auitable for use on motor coaches, particularly in the case of the enclosed types. Another useful outfit is that supplied for the decarbonization of cylinders without dismantling the engines; this consists of an oxygen cylinder with reducing valve, a length of hexibie tubing, and a special tool comprising a length of soft copper tube with a handle and small regulating
valve. •