THE WASTAGE OF COAL
By ALFRED C. BOSSOM, M.P.
from it, was some L750,000,000, but only about 3o per cent. of energy in the coal consumed during this period was actua:ly made available for use—the greater part, the remaining 7o per cent., being wasted in'polluring our atmosphere and warming our rivers.
One of the most difficult problems with which we have wrestled unsuccessfully for some 400 years has been the increasing amount of smoke, soot and grit belched forth by domestic and industrial chimneys over the country. Ten million tons of coal a year are wasted in smoke. This smoke, grit and dirt causes material damage to the tune of about L50,000,000 a year, not to mention that in- calculable factor beyond price, the despoliation of amenities and the arduous labour spent upon cleaning our architectural treasures, let alone the inside of our homes. Much of the ill-health in children and adults in industrial and urban areas is attributable to atmo- spheric pollution. and the heavy pall of gritty smoke which over- hangs these districts, cutting off good light, fresh air and sunshine. Those in authority are realising this general smoke-menace more clearly today than before, and the National Smoke Abatement Society is doing admirable work in keeping the question to the fore as much as possible.
From these brief facts it will be seen that waste in the con- sumption of coal is a large item in national expenditure. Indeed, if we are not to be faced with serious coal problems after the war, we must husband our coal with the utmost efficiency and economy. Naturally, the question arises: Can advantageous improvements be made? Two of the largest users of our coal are the gas and elec- tricity undertakings. A modern gas-works is a good example of how coal can be burped so that gas and various other valuable by- products are extracted, at the same time providing useful fuel in the form of coke. In certain modern gas-undertakings, such as that at Belfast, further fuel economy is effected by using coke to make producer-gas for firing retorts ; after it has done this useful work, the same gas is taken through waste-heat boi.ers to raise steam which, among other things, generates electricity from this waste heat. In less up-to-date undertakings, however, it is contended that over a week-end enough gas is often burnt at the flare of coke ovens to supply a fairly substantial town.
The production of electricity is, of Louise, a newer industry than gas, and there is little doubt that savings could be made if the scientific knowledge already available elsewhere were applied here. Professor C. L. Fortescue, in 1942, estimated that the Battersea and Barking Power Stations used 7o per cent. of their surplus heat for the sole purpose of warming the Thames, and that this heat could be employed industrially, and to give district-heating and hot water to homes in the neighbourhood. In addition, it is estimated that an industrial boiler can burn coal with an efficiency of 70-80 per cent., losing only 2o-3o per cent. of heat, but that a domestic grate or cooker only burns with an efficiency of about lo-15 per cent., which is, of course, a serious wastage. Can this be avoided? And for what better purposes can we use this heat?
Several other countries apply their waste heat to industrial and public services. It means that steam and/or hot water are avail- able in the neighbourhood surrounding a power-station, and are on tap in just the same way as cold water, gas' and electricity. Over 6o years ago the first live-steam main was laid in New York, and today they have over 7o miles of steam mains undet New York's main streets. In the U.S.A. there are over 16o cities whose people enjoy district-heating, thus obviating the carrying of coal to hun- dreds of individual fires and boilers, the cleaning of grates, clearing of ashes, dust, dirt and so forth. Russia, too, has developed a similar system and uses it quite extensively ; in 1939 there were 106 stations supplying district-heating. All Russia's new recon- structional plans are adopting this procedure as widely as possible, and I understand that some of her new industrial towns are to • have circulating heat and hot water over a radius of no less.than two miles. Germany, France, Italy and the Scandinavian countries have also had several such plants in operation for some years.
In 1943, coal delivered in bulk to large stations cost roughly 3os. a ton; but deliveries for household use averaged 6os. a ton. This over- head household charge could be almost eliminated by district-heating. Heat and hot water would be distributed to houses and flats in the vicinity of the station in just the same way as cold water is at present. Hot water would be on tap and steam-heated or hot-water radiators installed throughout. Such an experiment has been in operation for some time in Dundee, and the Bristol and Coventry town-planning authorities, in the new schemes for rebuilding their cities, all estimate that the average household should have all the heating and hot water required for a weekly charge of 3s., or possibly even less, to be included in the weekly rent. A great deal of wastage and/or leakage of heat occurs in buildings themselves. The attractions of an open fire are undeniable, but it is necessary to compute how much heat goes up the chimney, how much leaks -through our doors and windows. This leakage can be reduced by the use of modern stoves, capable of burning almost any kind of fuel and so designed that the doors in front of the fire can be opened for all to enjoy, while, if not so required, they can be shut down to contain the heat and use it for other purposes, such as space-heating, cooking and heating water.
Cold countries have almost stopped leakage of heat from doors and windows by practical insulation, technically known as weather- stripping. A thin, interlocking strip of sheet metal is placed around all doors and windows, automatically scaling the frames to prevent draughts and leakage ; in fact, the admission of fresh air into rooms is entirely at the control of occupants. Another device in growing use to prevent leakage of heat by radiation through the exterior of buildings is double sheet-glass window-panes. The latest method of handling these is to solder the panes together at about one- sixteenth inch apart by an unbroken solder-joint around the edges. Window-panes thus treated enjoy the same type of vacuum as does a thermos flask, and heat can only radiate through by very slow degrees. The Libby-Owens-Ford Company of America have carried out extensive experiments in this treatment of glass panes, and it is generally conceded there that, with the application of weather- stripping and the use of double-glass window-panes in domestic buildings, for the too per cent. of coal we burn today an equal amount of heat could be obtained from about 6o per cent. of fuel. The same principle can, of course, be applied to factories or any other large structure where considerable degrees of heat leak through doors and radiate through window surfaces. It is estimated that by this process no more heat would be lost than would pass through a solid 9-inch brick wall.
Another lesser opportunity of effecting economy is in arranging for all heating appliances and piping in any new post-war structures to be correctly fitted and well lagged. Radiators with reflec- tive insulation behind show a saving of some 6.5 per cent.; another to per cent. of fuel can be saved, and produces the same amount of heat, if burnt in properly constructed grates giving the maximum amount of radiation ; indeed, no one today will doubt that, with world competition at a keen cut-throat level, overhead charges brought about by wastage of fuel must be ruthlessly eliminated. Coal is very precious to us, and we can no longer afford to be spendthrifts with this, our one great natural resource.
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