THE SPONTANEOUS COMBUSTION OF OILY WASTE.

Taranaki Herald, Volume XL, Issue 9063, 22 April 1891, Page 4

THE SPONTANEOUS COMBUSTION OF OILY WASTE.

There is little doubt that a great many of the disastrous fires which occur only too frequently in the various centres of industry are due to a certain carelessness over the disposal of " cotton-waste," tow, rags, &c, that have been used for wiping up oil. Small quantities of oil are continually getting spilt , in workshops, and there is always a lot of waste in the lubrication of machinery, and a handful of " cotton- waste " seems to be the most convenient absorbent. A careless man will without a thought throw " waste" saturated with oil into the nearest corner, under the counter, or some other handy place ; ho might as well take a naked light into a powder magazine. When a fire happens such a one is the last to connect his own carelessness with the cause of the disaster. It is a matter of common chemical knowledge that there are many substances which are capable, when in a finely-divided condition, of burning vigorously at a temperature which is comparatively low, whereas, if such substances were in a solid compact mass, they would require a vastly hotter temperature before they would inflame. When pulverised antimony and arsenic, or finely-pow- , dered tin, copper, lead, and iron are projected into a jar containing dry chlorine gas, they immediately take fire, flashing out with brilliant scintillation ; but if these metals be exposed in lumps of considerable size in the same gas, they do not inflame, although doubtless chemical action takes place on their surfaces. If a portion of tow, " cotton-waste," or old rag be examined closely under a common microscope, the observer will at once perceive that it consists of tiny fibres, interlacing and crossing in every direction, very closely indeed, thus producing tiny spaces, or, as it were, pores in the general mass. A handful of such material may be regarded, therefore, as a kind of sponge. Again, oil is a substance capable of exertin a selective action upon atmosperic air, absorbing oxygen from if, some kinds of oil being especially active in this way. It is easy to..see, then, if we keep those analogous experiments which we have already discussed I in mind, that a mass of oily " waste " certainly will absorb, and probably condense, atmosperic oxygen ; oxidation will then ensue as a natural consequence. This is che- j mical action, and such action is invariably accompanied by a rise of temperature. Heat generally quickens chemical action, therefore the rise of temperature will accelerate the oxidation going on in the mass of oily waste. Thus we see that the process proceeds with an ever-increasing rapidity, so that the oxidation goes on at a greater and greater rate, just as a falling stone does under the action of gravity, and the temperature consequently rises faster and faster till a point is reached, termed the " temperature of ignition," when the whole oily mass begins to smoulder and finally burst into a flame. Now, if a mass of " wa->te," in this condition, bo lying upon a concrete floor, it goes without saying that little harm will ensue ; but such dangerous materials are not usually placed carefully upon concrete floors — they are more often thrown away anywhere into some odd corner. Unfortunately, it is the habit of waste paper, shavings, bits of straw, sawdust, and other useless, but inflammable, matters to congregate also iv such odd comers ; so now we see how the mischiei is done. Some substances are extremely good con ductors of heat ; thus the metaljs are, espe daily silver and copper; other substances are very bad conductors. Down is one of the worst conductors known. Flannel, cork, wool, sand, asbestos, nil conduct heat very badly, and will remain without losing their heat to any appreciable extent for a considerable time. In fact, porous bodies of all kinds conduct heat very slowly ; hor.ee in cold weather we wear woollen clothes to prevent the escape of heat from our bodies, and steam pipes are jacketed with some such material for similar reasons. A mass of oily tow or " waste " is a porous body, therefore is a low conductor of heat, and the very fact of its low conductivity facilitates the spontaneous combustion by preventing a loss of the heat generated, whereby if it were a good conductor the heat evolved during the oxidation might be communicated so rapidly to surrounding objects that the mass of waste would never reach the " ignition temperature." There are authentic instances on record of , sawdust, which has been strewn upon the floor to absorb the drippings of olive-oil, igniting in a few hours during the Summer time. Linen rags that have been used as wrappers for packages of butter have* been known, when thrown aside in a heap, to begin to smoulder in less than twenty-four hours. ' Sufficient has been said to emphasise the danger which arises through the careless disposal of oily waste. But the British workman is notoriously an apathetic individual — it takes a lot to impress him ; perhaps the only thing to hope for is that foremen and managers will adopt a strong position, and lay down stringent rules which shall provide for the safe disposal of such dangerous materials, and further to insist on these regulations being strictly adhered to. An easily-accessible receptacle should be provided, into which all rags, water, sawdust, &c, used for soaking up oil should .be immediately placed after use, and at night all such acumnlation should be either safely burnt or thrown into water. In many industries a great deal of waste occurs in this way, and in such cases the rags, &c, could be thrown into an alkali vat and the oily matter saponified ; this process would eliminate a considerable item of profit-leakage.

A case — A coffin. Some women are worth their weight is soold. An opera-singer sings airs, and puts them on too. A young man boasted that be had a well* stored mind, whereupon a young lady murmured : •' What a pity we can't find out where he stored it J" " Died from exhaustion," was the coroner's verdict in the case of a woman who had climbed twenty-five pair of stairs looking at new styles of spring bonnets. A popular concert singer, advertised to participate in an entertainment in a Missouri village, excused her absence on the ground of having a cold in the head ; the next day she received the following from an admirer: " This is gouse greze ; melt it and rub on the brige of yore noz until kured. I luv you to distraxshun." During a dense fog a large river steamer had to cast anchor. A traveller, anxious to go ahead, came to the man at the wheel and asked why they stopped. " Too much fog — can't see the river." " But you can see the stars overhead." '• Yes," replied the sailor, "" but until the biler busts we ain't going that way."