Coal fire

“ "I have sat before the dense coal fire and watched it all aglow, full of its tormented flaming life; and I have seen it wane at last, down, down, to dumbest dust. Old man of oceans! of all this fiery life of thine, what will at length remain but one little heap of ashes!" ”

“ So it is that by hard work and much danger we get coal for burning. Now, coal is dirty and heavy. A coal fire is hard to kindle and hard to put out, and the ashes are decidedly disagreeable to handle. And after all, we do not really burn the coal itself, but only the gas from it which results from the union of carbon and oxygen. In some places natural gas, as it is called, which comes directly from some storehouse in the ground, is used in stoves and furnaces and fireplaces for both heating and cooking ”

“ A coal fire, as we all know, burns slowly, for the simple reason that it is only at the surface of the lumps that carbon and oxygen are in contact. If we grind up the coal into a fine powder and then blow it into a cloud, so that every tiny particle is surrounded with air, a spark will cause an explosion. ”

“ But besides the flame, which is a peculiar gas in the state of combustion, heat expels from coal an aqueous vapour, loaded with several kinds of ammoniacal salts, a thick viscid fluid resembling tar, and some gases that are not of a combustible nature. The consequence of which is, that the flame of a coal-fire is continually wavering and changing, both in shape, as well as brilliance and in colour, so that what one moment gave a beautiful bright light, in the next, perhaps, is obscured by a stream of thick smoke. ”

“ A coal fire, when well kindled, needs only air enough to keep it burning. When the coal becomes red all through, it has parted with the most of its heat, and the fire will soon die unless replenished. ”

“ There is also "white-damp," the gas which you [Pg 8] see burning with a pretty blue flame over a hot coal fire. Worst of all is the "fire-damp." If you stir up the water in a marsh, you will see bubbles of it rise to the surface. It is harmless in a marsh, but quite the opposite in a mine. When it unites with a certain amount of air, it becomes explosive, and the least bit of flame will cause a terrible explosion. Even coal dust may explode if the air is full of it, and it is suddenly set in motion by too heavy a blast of powder. ”

“ When the fire-damp comes off suddenly in any case, rendering the air foul and explosive at the foreheads, if no other remedy be found effectual, the working of the coal must be suspended, and a current of air sent directly from the fresh in-going stream, in order to dilute the explosive mixture, before it reaches the furnace. This is termed skailing the air; for otherwise the gas would kindle at the furnace, and flame backwards, like a train of gunpowder, through all the windings of the work, carrying devastation and death in its track. ”

“ A fire so covered will often keep smouldering for days, and can be re-lighted by adding fuel and admitting air, a most important consideration in the days of tinder-boxes. The same custom is still pursued in the backwoods of America, in the Australian bush, and in our own ‘black country,’ where the great coal fires are ‘raked’ in the old fashion nightly. ”

“ It involves the keeping dean of flues, ashpits and especially the fires themselves. Where coke or ordinary hard coal are used, the removal of clinkers should be done systematically, and the fires stirred. Anthracite coal fires should not be stirred more than is absolutely necessary, and should not be fed in driblets. They require more draught than coke fires, but care must be taken not to give too much, as excessive heat is likely to melt or soften the fire-bars. ”

“ The flame of an ordinary coal-fire is due to the distillation and combustion of tarry vapors. If such a flame strikes a comparatively cool surface like that of the meat, it will condense and deposit thereon a film of crude coal-tar and coal-naphtha, most nauseous and rather mischievous; but, if the flame be that which is caused by the combustion of its own fat, the deposit on a mutton-chop will be a little mutton-oil, on a beefsteak a little beef-oil, more or less blackened by mutton-carbon or beef-carbon. ”

“ On the other hand, supposing a gas fire is lighted in a sitting-room in the morning, it can be turned out if the family are out in the afternoon, and not relighted until shortly before they return, for the advantage of gas and electric fires is that they are red-hot practically at once, whereas a coal fire takes time to burn up and become hot, and each time it is lighted it eats wood as well as coal. ”

“ The fire is amongst the rubbish of the old work, and so close to the crop of the coal that the heat has the effect of melting the snow presently on the ground there. The fire is in a state of simple agitation, that is red hot, but no flame, and it is surprising to find how very little progress it has made in the space of ten years. It is very remarkable that no smoke or vapour from the burning mass has appeared at any one of the numerous pits which are upon this nine-feet coal ”

“ The somewhat dim coal-fire has an essential influence in producing the effect which I would describe. It throws its unobtrusive tinge throughout the room, with a faint ruddiness upon the walls and ceiling, and a reflected gleam from the polish of the furniture. This warmer light mingles itself with the cold spirituality of the moonbeams, and communicates, as it were, a heart and sensibilities of human tenderness to the forms which fancy summons up. It converts them from snow-images into men and women. Glancing at the looking-glass, we behold—deep within [39] ”

“ I have often wondered that no attempts should have been made to improve the fires which are made in the open Chimnies of elegant apartments, by preparing the fuel; for nothing surely was ever more dirty, inelegant, and disgusting than a common coal fire.
Fire balls of the size of goose eggs, composed of coal and charcoal in powder, mixed up with a due proportion of wet clay, and well dried, would make a much more cleanly, and in all respects a pleasanter fire than can be made with crude coals; and I believe would not be more expensive fuel. ”

“ That fresh coal should be put in front of or at the bottom of a fire, so that the gas may be thoroughly heated by the incandescent mass above and thus, if there be sufficient air, have a chance of burning. A fire may be inverted, so that the draught proceeds through it downward. This is the arrangement in several stoves, and in them, of course, fresh coal is put at the top. ”

“ The flame produced from coal, wood, turf, oil, wax, tallow, or other bodies, which are composed of carbon, hydrogen and oxigen, proceeds from the production of carburetted hydrogen gas, evolved from the combustible body when in an ignited state.
It must have been noticed at the same time, that in the common mode of burning coal in a fire-place, or stove, nearly the whole of this inflammable gaseous matter is lost. We often see a flame suddenly burst from the densest smoke, and as suddenly disappear ”

“ Underground fires are not uncommon accidents in coal-mines. In the thick coal workings in South Staffordshire the slack left behind in the sides of work is especially liable to fire from so-called spontaneous combustion, due to the rapid oxidization that is set up when finely divided coal is brought in contact with air. The best remedy in such cases is to prevent the air from gaining access to the coal by building a wall round the burning portion, which can in this way be isolated from the remainder of the working, and the fire prevented from spreading, even if it cannot be extinguished. ”

“ The object of such a method is the preserving of a bed of carbon at the rear of the grate, in passing over which the volatile gases driven off from the green coal will be burned. This method is particularly adaptable to a grate in which the gases are made to pass horizontally over the fire. Modern practice for hand firing leans more and more toward the spread firing method. Again the tendency is to work bituminous coal fires less than formerly. ”

“ Put a shovelful of soft coal into your furnace and watch the thick, yellow gas hover over the black mass before it bursts into flame. Open a draft below the fire box. The oxygen in the air helps to make a hotter fire. Hot air rises. you can see these gases and coal dust rush up the smoke pipe, on the column of hot air. They are carried away before they have time to burn. Of course, then, you understand that smoke means waste of fuel. Under boiler and house furnace fires, from two to five tons of coal are burned to produce the heat that is in one ton. ”

“ A burning coal glows with red light, and so does a piece of iron placed in a coal fire. But the coal and the iron are undergoing very different processes. The coal is burning, and will presently be consumed; the iron is not burning (except in the sense that it is burning hot, which means only that it will make any combustible substance burn which is brought into contact with it) , and it will not be consumed though the coal fire be maintained around it for days and weeks and months. ”

“ If the pile is near enough to the breaker to menace it, or near enough to an outcrop to carry combustion into the coal of the mine, the fire must be extinguished, and this is sometimes done with much labor and at great expense. If no danger is apprehended, the fire is allowed to smoulder until it burns out, a process which may take months or even years, during which time little blue flames [191] flicker on the surface of the bank, the sky above it is tinged with red at night, and the whole black hillside is finally covered with great blotches of white ash. ”

“ Thus, a parlour fire will consume in twelve hours forty pounds of coal, the combustion rendering 42,000 gallons of air unfit to support life. Not only is that large amount of deleterious product carried away, and rendered innoxious by the chimney, but five times that quantity of air is also carried up by the draught, and ventilation is thus effectually maintained. ”

“ When burning coal, spread the coal all over the surface of the fire in a thin layer so as not to smother it and thus make it burn with a smoky flame. Keep the ashes cleaned out from underneath the fire and around the fire pot. ”

“ When the coal begins to burn well, add enough fresh fuel to come nearly to the top of the lining of the fire-box. Keep the front draught open until all the coal has become ignited, but not until it becomes red-hot. ”

“ It is not thought to be given off in appreciable quantities by the coal at the open faces; but it is formed when the carbonic acid passes through any ignited carbonaceous material, or when steam passes over burning coal. It is therefore produced most frequently by smouldering gob fires, by burning wood in the mines, or by a shaft on fire, and may exist as one of the results of an explosion of fire damp or of blasting powder. It is the most to be dreaded of any of the gases which the miner has to encounter. ”

“ Nearly every one has noticed the blue flame with which coal burns in the parlor coal heater or in other furnaces where little draft is used and most of us remember that the gas which is given off from such a fire has asphyxiated many who were unfortunate enough to be sleeping in a closed room, when through insufficient chimney draft or a leaky stove some of the unburnt gas filled the room. ”

“ In such circumstances the mining engineers or coal viewers have a dangerous and difficult duty to perform. The pit into which they must descend as soon as possible, is rendered unsafe by many causes; by the wrecks of loose timber torn away by the eruption, or by the unrespirable gases; by the ignition perhaps of a portion of the coal itself, or by the flame of a blower of fire-damp; either of which would produce violent and repeated explosions whenever the gas may again accumulate to the proper degree. Such a predicament is not uncommon, and it is one against which no human skill can guard. ”

“ In some places, where there is no fear of bad gas, and open lights can be used, the coal is blasted by gunpowder, as rock often is. This, however, cannot often be done; as the bad gas, called fire-damp, may come up any moment, and if set light to, go off like gunpowder or the gas from coal, and blow the chambers and everybody near to pieces. ”

“ A second effect claimed is relief of the incandescent coal from the weight of the body of superincumbent coal, thus preventing the compression of the burning coal in the fire-pot, and securing for the flame free expansion, thus enabling it to act with greater heating effect upon the lower portion of the stove in its passage to the smoke and draft flue. ”

“ The only unprotected portion of the plant is the coal shutes leading directly to the fire rooms. Although the idea was undoubtedly suggested to him Von Lertz was keen enough to realize its worth. Women gathering up coal which has been spilled in the unloading of cars into these shutes, is an ordinary sight. Workers of ours will go to the shutes, ostensibly to gather waste fuel, carrying lumps of coal which have been hallowed out and filled with trinitrate of toluol and will slide these chunks down the shute. ”

“ You will easily understand that a grate for burning coal alone, especially hard coal, may be much smaller than a fireplace to hold hickory logs that it takes two men to carry; but the heat of anthracite coal would soon destroy the lining of a fireplace adapted to an ordinary fire of wood. ”

“ When the reverse is the case, the draught is commonly too languid, the fire draws badly, a portion of the smoke escapes into the room, and all the usual annoyances of a smoky chimney are suffered. By a proper attention to these conditions a common fire-place may be adapted for the combustion of bituminous or easy burning coal, or of anthracite, and varieties of coal that require a considerable draught. ”