Gas-Engines and Producer-Gas Plants / A Practice Treatise Setting Forth the Principles of Gas-Engines and Producer Design, the Selection and Installation of an Engine, Conditions of Perfect Operation, Producer-Gas Engines and Their Possibilities, the Care of Gas-Engines and Producer-Gas Plants, with a Chapter on Volatile Hydrocarbon and Oil Engines

by Rodolphe Edgard Mathot

Manufacturers have succeeded in devising apparatus remarkable for the simplicity of the processes employed

and yielding economical results which would never be obtained with pressure-generators employing gas-holders and boilers, considering that the boiler alone calls for a consumption of from 15 to 30 per cent. of the total amount of coal used for making the gas.

The best results obtained by the author with pressure gas-producers have indicated a consumption of not much less than 1 to 1¹⁄₄ pounds of anthracite per horse-power per hour at the motor, while with suction-generators, under similar conditions and with the same grade of fuel, he has repeatedly found a consumption of from ⁹⁄₁₀ pounds per effective horse-power per hour. In either case, the gas obtained developed between 1,100 and 1,300 calories (4,365 and 5,158 B.T.U. per 35.31 cubic feet) if produced from anthracite yielding from 7,500 to 8,000 calories (29,763 to 31,746 B.T.U.) per 2.2 pounds.

The suction apparatus will also work very well with inferior coal containing up to 6 to 8 per cent. of volatile matter and from 8 to 10 per cent. of ash. This great advantage added to all the others explains the favorable reception which European manufacturers at once gave to suction-producers. The petroleum engine itself will find a serious competitor in the new system.

As regards the possibility of employing suction gas generators with respect to the somewhat peculiar properties of the fuel, it may be said at the outset that coke from gas works yielding from 6,000 to 6,500 calories (22,911 to 24,995 B.T.U.) and also charcoal are perfectly available.

One horse-power per hour is obtained with a consumption of 1.1 to 1.3 pounds of coke.

Blast-furnace coke may be used in case of need, but its employment is not to be recommended on account of the sulphides it contains, which sulphides, being carried along by the gas, are liable to form sulphuric acid with the steam, the corrosive action of which would soon destroy the cylinder and other important parts of the engine.

Qualities of Fuel.—Anthracite coal is, upon the whole, so far the best available fuel for generators. However, it should possess certain qualities which will now be briefly indicated.

In suction gas-generators, above all, it is important that no harmful resistance should be opposed to the passage of the air and of the gas produced. It is therefore necessary to employ coal of a size that will answer the foregoing condition, without being too expensive.