Show AIR RECEIVER explosions by letson balliet E M in the salt lake mining review of march 30 1 I omitted to state the time when air receiver explosions are mostly likely to occur and in fact the time when most of them do occur in almost every case which I 1 have investigated vesti gated the operator has said 1 I was just starting up I 1 quite ot up to pressure and where rc recording cording gauges have been in the line far enough away not to be destroyed the records have never within my experience shown much if any over pressure air receiver explosions almost always occur immediately after a short shut down tor for example just after dinner or following a shift change or some other short period of compressor idleness there is a reason why this should be so work is suspended and the air flow stopped accumulated oil gasses being lighter will separate from the air as they are merely a physical mixture with it oil gasses contain considerable per cent of hydrogen the lightest of known gasses hydrogen when mixed with oxygen of the air and ignited by a spark will produce a powerful explosion to augment this is the accumulated oil from the lubricators lubrica tors which have continued to feed oil into the cylinders after the compressor began to slow down and perhaps for a greater or less time after it stopped the heat of the compression the gasifying of the vapors and the gas and air mixture when ignited by a spark produces the explosion A simple experiment will convince you that you cannot explode air take two five gallon cans that coal oil or gasoline comes in solder them up air tight with a piece of pipe soldered in to each for an inlet connect this pipe in one to your mining and efficiency engineer hotel oakland oakland california air hose and turn on the air till you tear it apart nothing happens except that the can will spring a leak in the other can solder an old spark plug from your auto and then pour in two or three spoons full of gasoline after which connect with your air hose and put up merely ten or fifteen pounds pressure and still nothing happens now take a long wire and connect it to one of terminals of your auto which is to he be standing around a corner somewhere and to the spark plug and then give the crank a spin what happens the spark causes a violent explosion even when the pressure is but ten or fifteen pounds what happens when the air receiver blows up only you have an oil gas instead of a gasoline gas if you wish to further satisfy yourself take another perfectly clean dry and long empty can solder the inlet and the spark plug into it as before and pump up the pressure with a dry air till you bulge the can and then try to spark the air which has no gas vapor in it and nothing happens for air does not explode without a combustible bus tible gas mixture exists |