GAS FOR THE CITY

Evening Post, Volume LXXXIV, Issue 31, 5 August 1912, Page 3

GAS FOR THE CITY

FROM NEW WORKS AT MIRAMAR MODERN PLANT IN OPERATION. HOW SCIENCE SAVES LABOUR. (By " Autos.") That landmark of the Peninsula, the big gasholder at Miramar, has for some time past been a reservoir of gas lor maintaining a supply for the city, but few people know that gas is actually being manufactured on a large scale alongside for general consumption. The new works, though not complete in every detail, . are in active operation, and a good deal of the city' 3 gas now comes from Miramax 1 . By and by, if will all be made there, but that is looking rather far ahead at the present time. FROM THE COLLIER AT THE WHARF. The first significant evidence of abnormal activities at Miramar lies in the intercolonial collier Brisbane, discharging Newcastle coal at the new wharf for the gasworks. For the present, the coal is being carted through the cutting to tho works just on the other side, but in a short time the rails, which extend from works to wharf, will be put in commission, , and a tiny locomotive will haul specially-designed coal-trucks to and fro with supplies for the production of gas. The colliers will discharge directly into these six-ton hopper wagons, and the coal will then be taken in a few minutes direct to the entrance to the large reinforced concrete coalshed, which is one of the most conspicuous features in the new works. In such a method of transport there is. obviously a great saving over ordinary horse cartage. THE SH«VEL SUPERSEDED. But this is only the beginning of tho labour-saving appliances which make the G»s Company's Miramar works probably the most up-to-date 6outh of the Line. The coal wagons are shunted over a sort of 'pit, where the contents of each truck are automatically deposited by the movement of a lever opening the bottom of .the truok and. letting the coal fall through. Then begins the series 01 automatic conveyer*, which iunh right through the works. Electric motors drive endless chains in trough form, which' carry up the coal at the rate of, seventy . tons an .hour through a .pulveriser, which breaks the bi<j lumps into the great long concrete shed, where it is deposited in heaps at any g_iven point. By ingenious mechanism ot a similar character, the coal can be shifted .automatically again 'to any. desired position. There is no need whatever for the army of men stirring up choking, black coaldust with 6hoyolfl and wearing themselves out in primitive labour. - Everything is done in a simple, orderly manner oy slow-moving machinery. THE GAS DISTILLERY. Alongside, but a little further down, is the retort-house, a huge, lofty galvanised iron shed, .very reminiscent of a colliery sorting and screening house. In this retort-house the gas which lights the house and cooks the dinner is actually being made. It is totally different from the old style of gas-making. There, as may be seen at CoUrtenayplace',' the coal was shovelled into - horizontal retorts of fireclay, something' like a big drain-pipe stopped up at one end. Round Hie retort's were exceedingly hot fires, which distilled gas from the coal inside the retort," ana loft the "glowing coke behind. It was in the extraction of this, by long iron rakes, that the strength and stamina of the {jas-workei was so much' tried — in fact, is to day, wherever tho old system obtains. In drawing the retort he had to face the white hot coke and pull it out towards him with the rake. To be a gas-worker a man had to be sfcrong physically and constitutionally, " and this part of the work was very arduous. HOW THE GAS IS MApE. At Miramar they have changed all that. Only a handful of men are roquired to work the retorts. .These are now huge vertical bottles of fireclay, opening at both top and bottom when required. The coal is Bhot in automatically from bunkers overhead, automatically supplied with coal from automatic conveyors. The heating of the retort is on the principle of the suction gae producer, and 6howfl similar economies in fuel. The coal stays in the retort about twelve hours, by which .time all the gas has been driven out of it, and the residue is pure coke or carbon. With tho vertical. retort there is no drawing out of the hot coke by. main strength of muscle and sinew at the end of the iron lake. Instead, tho gas works . operates a few levere, turns a handle, ana away comes a. torrent of incandescent coke falling. into an automatic conveyor under a heavy 6pray of water. Clouds of steam rush up, and for a moment fill the retort house, only to drift out under the open eaves. AUTOMATIC THROUGHOUT. So the work goes on as in one giant machine. The coal comee in from tho collier by way of the truck on the light railway, is dumped on to the lifting conveyors, and carried up continuously fo the coal storehouse. From there it is lifted by automatic conveyors to the top of the retort house, whero it fills the bunkers above the narrow mouths of tho retorts. From the bunkers in one operation the coal shoote into the bottleshape retorts. It stays there half a day, under conditions 6f heat regulated by exact science. The temperatures are measured by pyrometers, and everything is arranged for tho production of the greatest quantity of the beet gas with a residue of the best coke. At the end of that period, the retort is drawn m the manner described, and the coke still steaming, conveyed out to bunkers in the open ah", fiom which it is shot into carte, wholesale or in bags, in all sizes required, through a revolving screen. It can be said that not a hand touches the coal or the coke until it gets into the yards in town. The human element of back-aching, grinding toil is replaced by the human element of the skilled supervision of a vast machine. PURIFYING THE GAS. All th« tune the coal is in tho fiery furnace of the retort the gas comes off in full quantity. It ie not, however, ready or fit for domestic use then. It has to und/ergo several processes of cleansing and purification 'firpt. It goes first from the retort by way of a water wjaled main to the condenser — a large piece of apparatus, like an iron tank externally. Here by a system of perforated tubes the gas ie passed through water which removes moat of the tar. From the condenser it is drawn out by a rotary exhauater, and then driven through a big rotary extractor, the basic principle of which la tho beating of th« gas by revolving brooms, as it •were, dipping into water. This takes tho remainder of the tar and the ammonia. Finally, to remove tho sulphur, which comes through-from the coal m tho shape of eulphurottsd hydrogen, the gas is pumped through water tMiks containing quantities of red oxide of iron. This picks up the sulphuretted hydrogen loraiing bulphide of iron. The ga6 is vow pure, ( and; as such', passes into thfe' huge jr'ashjilder of a capacity of one and aMI Sn'Ufoii cubic feet., From.

thence through a hug© gae meter, like a 'mausoleum in shape, ifc goes away on its' road to town to -carry out its varied work of lighting, heating, cooking, and generating power. Its purity and quality are tested all the time by special appliances iv tho meter house. THE LAST WORD. To run the -works considerable power is required, and this is generated iv a separate station. Threo national gas enginee of 62 h.p. and 35 h.p. (2) respectively drive dynamos to supply current for the electric motors, which actuato the automatic conveyors and other appliances in the coal storehouse and retort house. The rotary exhausters and compressors, of which four are installed, and the tar-extractor, or washer, are all driven by separate simple steam engines, steam being supplied by two Babcock and Wilcox watortube boilers fired with breeze coke under forced draughtProvision is made for increasing the plant at requirement. At present tho works ar« in the rough piehnunary stack of working, and it will be a few month* before the final touch is added. The recent bad weather interposed delays in several directions, at) the ground became very soft. The whole site of the works i* a. network of underground mains, but this work is practically complete. It will probably be about Christmas-time before the whole of the great plant, with its -many buildings, its pair of chimney stacks, and its system of railways and automatic transport can be brought to_ the highest pitch of working efficiency, for slight adjustments here and there are always necessary at the start. But it can safely b© said that in the completeness of its design the whole plant must be reckoned as the laet word to date m the manufacture of gas.