FIG. 224.—ACETYLENE GAS APPARATUS.
A very simple apparatus for the purpose is shown in [Fig. 224], in which a vessel containing water has an inverted bell or cylinder within it, open at its lower end. A basket or cage is suspended within the inner cylinder, and contains a few lumps of calcium carbide, which are first immersed in the water by being forced down by the rod supporting the same, which passes through a stuffing box. Acetylene gas is immediately generated and its pressure forces the level of the water down in the inner cylinder, causing it to rise in the annular space between said cylinder and the case. As the water level descends in the inner chamber it passes out of contact with the calcium carbide, and the generation of gas is discontinued until some of the gas is drawn off or consumed at the burners, whose pipe is shown connecting with the gas space of the inner cylinder. When so drawn off, the pressure in the inner cylinder is relieved, and the water therein rises to contact again with the calcium carbide and renews the generation of gas. This principle of automatic action is a very old one, and will be recognized by the student as that of the Dobereiner lamp of the chemical laboratory, invented by Prof. Dobereiner, of Jena, in 1824.
FIG. 225.—MULTI-CHARGE ACETYLENE GAS GENERATOR.
In acetylene gas apparatus a great variety of methods are employed for bringing the water and carbide into contact. Instead of the automatic pressure level principle described, many devices discharge a regulated quantity of powdered calcium carbide into the water, while in another form the water is discharged upon the calcium carbide. An example of the latter is given in [Fig. 225], which represents the Criterion generator. A number of receptacles containing charges of calcium carbide are made to successively receive a regulated quantity of water, the gas being collected in a rising and falling holder.
Acetylene gas finds its principal uses for isolated plants, and in country houses. One form of using it is to compress it under high tension in cylinders, but this method has been attended with some disastrous explosions, and is discriminated against by the insurance companies.
Calcium carbide is now made in a large way by the Willson Aluminum Company, at Spray, N. C., and also at Niagara Falls and at Sault St. Marie, Mich., and its cost is between 3 and 4 cents per pound.