International Combustion


| September/October 1976



The Brayton Hydrocarbon Engine

The inherent complexity of the steam engine - with its attendant furnace, boiler, pumps, coal bunkers, ash pans, and myriad other adjuncts - and the necessity of employing a licensed engineer full-time were defects obvious to users and manufacturers of steam power. The constant threat of boiler explosion was a source of anxiety to the general public too. As a result, inventors sought to harness energy sources based on some completely different principle - sources able at least to compete with steam, and ideally to supplant it. When suited to the particular situation and where available, water power was employed, and, to a far less extent, wind. Both had topographical and geographical limitations that excluded them from anything like universal use.

The most attractive alternative energy source was the explosive power locked in such combustible substances as gunpowder, gas, and a variety of liquid vapors. Systems were developed to burn such fuels directly in the cylinder of an engine based loosely on the steam engine, the pressure resulting from the combustion forcing a piston out of the cylinder - a notion suggested, of course, by the cannon. Throughout the 19th century a host of inventors struggled to find better fuels, to develop means for introducing just

the right amount of fuel into the cylinder in a cycle that would produce continuous motion, to discover the best way of igniting the fuel at precisely the right moment, to control the explosive violence of combustion, and to solve innumerable other problems that stood in the way of a successful internal combustion engine.

By the 1840's several engines had been invented that burned either illuminating (coal) gas or volatile liquids. They operated poorly. Not until 1860 was one invented that became commercially successful: a gas engine patented by J. J. E. Lenoir of Paris. Hundreds of Lenoir engines were built in France and England for light industrial applications. They were able to compete with steam engines - even though the latter were far more efficient - because they could be started instantly, they consumed no fuel when not actually working, they occupied much less space, and they were free from the danger of explosion.

It was not the Frenchman Lenoir, however, but the German Nikolaus August Otto who solidified the position of internal combustion as an important source of mechanical power. In 1867 an engine designed by Otto and his associate Eugen Langen was shown at the Paris Exposition. Tests revealed that its gas consumption was about half that of the Lenoir engine and another competing engine.

Although makers of steam engines and boilers scarcely had much cause for alarm, by the time of the Centennial internal combustion engines were being sold in considerable numbers. As at Paris nine years earlier, three engines were shown at Philadelphia: one French, one German and one American. The judges gave the Mignon & Rouart 'Noiseless Gas Motor' a somewhat left-handed award, praising its simplicity of construction, and declaring it capable of rendering 'good service in cases where economy of gas is not of the first importance.' To be taken more seriously, though, were the other two engines. One was the Otto & Langen, successful for nearly ten years and on the verge of giving way to Otto's four-stroke-cycle engine. The other was the Brayton Engine, the first practical liquid-fueled internal combustion engine. It was the dawn of an era.