Rudolf Christian Karl Diesel (1853 - 1913) Diesel started his education in Paris and spent most of his time in the museum of arts and crafts. The outbreak of the Franco-Prussian War forced him to leave Paris and go to London. He later studied in Munich under the German chemist Carl Von Linde. He invented the refrigeration system used now in many electrical refrigerators. Diesel grew to become a very important engineer and inventor. He attempted to find better ways to use steam as the working fluid in heat engines. His patents in 1892 and 1893 were not for the engine but for the cycle of an engine employing the compression-ignition technique. In this cycle there were four phases. He did not have one fully rolling until 1897. Diesel attacked the problem of the compression-ignition engine not as a new concept but as a refinement of the petrol engine inventd by Nikolaus Otto in 1876. He spent the rest of his life introducing his invention to the world. He had many problems with manufacturing, licensing and financial stability. On Sept. 29, 1913, Diesel vanished off the Harwich-Antwerp ferry crossing the channel to England and his body was never found. Since his death the diesel engine has been very helpful in manufacturing and transportation.
The Diesel Engine Diesel revised his original model and on February 17, 1894 the new engine ran for over a minute. It took nearly three years to produce a viable working model. The engine he produced had a mechanical efficency of over 75% where the steam engines of the time were operating on less than 10%. Once the engine had been proven, Diesel became a rich man. By 1898 he was a millionaire from sales of the rights to his engine. The U.S. rights went to a Missouri beer manufacturer, Adolphus Busch. His results and sales were so impressive that they were used in nearly all US submarines during WWI. The Vickers company modified the pump and in 1914 William T. Price managed to successfully reduce the compression ratio in the engine. The diesel engine does not require a large water supply or a long warming-up period and is highly efficient in converting heat energy into work. Diesels are widely used in both stationary and mobile installations where the power required is between that furnished by the petrol engine and that of the steam turbine and where the relatively high initial cost can be written off over a long period. For example, diesels having capacities of 100 to 5,000 hp are employed on industrial and municipal electric generators and on continuously operating pumps (e.g., on oil pipelines). Moreover, they occupy relatively little space compared with steam units, since no boiler is needed — a factor of importance aboard ships. The diesel engine differs from the petrol engine in that the ignition of fuel is caused by compression of air in its cylinders instead of by a spark: the high compression ratio allows the air in the cylinder to become hot enough to ignite the fuel. Because of the high temperatures of operation, a diesel engine must be water-cooled. The construction of the diesel engine is heavier than that of the petrol engine; there are usually three or more cylinders (supported on a framework and bedplate) and a heavy flywheel. The cylinders are set to work alternately to give a smooth-turning effect, and the flywheel contributes further to smooth action. There are two classes of diesel engines. In the two-stroke, or two-cycle, type there is a complete cycle of operation in every two strokes of a piston. This type of engine requires a supply of compressed air for operating and for starting. In the four-stroke, or four-cycle, type the first downstroke of the piston draws in air, which is compressed on the upstroke to about 35 kg per sq cm.(500 lb per in2). At the top of the stroke a jet of oil is sprayed in through an injector. The oil is ignited and the rapid expansion of the gas created by the explosion forces the piston down in the working, or firing, stroke. The next upstroke drives the waste gases out through the exhaust valve, and the cycle is complete. The speed and power of the diesel are controlled by varying the amount of fuel injected into the cylinder, not the amount of air admitted as in the petrol engine. Small and medium-size ships may have several diesels producing as much as 50,000 hp. Heavy-duty land transports such as trains, trucks, buses, and tractors are often diesel-powered. A few automobiles and even some airplanes have had diesel engines. By the 1960's, half of the world's total tonnage of shipping was powered by diesel engines and nearly half the world's locomotives were diesel-driven.
NOTES © MBM 2001 |