AUTOGENOUS PLUMBING AP PARATUS. The purpose of this apparatus is to provide, by means of the reaction between oil of vitriol, water and zinc, a supply of hydrogen gas, and, after mixing it with air, to burn the mixture at the end of a blowpipe nozzle, and, by means of flexible rubber tubing, apply the flame readily to the work in hand. By its aid lead sheets, pipes, etc., may be joined together by melting the points of junction, without the use of solder or flux. It can also be used for soldering, brazing and annealing; in fact, for any purpose requiring an intense heat locally applied. It consists of a rectangular box di vided into two closed compartments. The upper i one is an acid chamber, opening at the top, and a pipe connects it with the bottom of the lower compartment. The lower compartment is the zinc and gas chamber, having a pipe near its top to convey the gas generated into a purifier arranged in the space between the upper and lower compartments. This space also contains the opening into the lower com partment, through which the zinc is inserted. The dilute acid runs down the pipe from the upper chamber into and up through the zinc in the lower chamber, in the upper part of which the gas collects, and passes out by a bent pipe into the bottom of the purifier. The purifier is a box intended to collect any drips which may pass over with the gas. From its upper part a pipe conveys the gas to the bottom of a second purifier, filled with water, through which the gas rises and passes to the blowpipe. The
water removes any sulphurous acid gas or other impurities that may pass over with the hy drogen gas.
The rear end of the blowpipe is divided into two branches. To one of these the tube conveying the hydrogen is attached, and to the other a tube conveying air driven in by a bel lows. The hydrogen and air combine and mix in the blowpipe, and flow out of its nozzle, when the mixture is ignited for application of the flame to the work. Lead sheets may be joined edge to edge or by a lap. In the former case lead straps are melted along the joint to perfect and strengthen it. The apparatus is used when lining pickling vats, covering floors with lead, etc.; also for annealing the serrated wires for friction primers.
In and near the larger cities, where com pressed gasses may be bought in portable cylin ders, the hydrogen-making apparatus may be dispensed with, and the oxy-hydrogen blowpipe substituted. In the latter case coal gas or blau-gas may effectively take the place of the pure hydrogen. The gasses from the portable cylinders are very easily conducted to even the most contracted localities by the simple length ening of the rubber conducting tubes. Consult Clarke, J. W., (Modern Plumbing Practice' (London 1914).