EXPERIMENTS ON A STEAM-ENGINE, THE CYLINDER OF WHICH WAS HEATED EXTERNALLY BY GAS-FLAMES

B DONKIN
1889 Minutes of the Proceedings of the Institution of Civil Engineers  
IN the following experiments an attempt has been made to determine how far cylinder-condensation can be prevented, and an economy of steam realized by heating an engine cylinder externally by gas-flames, so as to raise its temperature considerably. The engine was of the horizontal single-cylinder type. Diameter of cylinder, 8,7, inches ; stroke, 14 inches. It was coupled direct to a rotary gas exhauster used merely to pump air so as to absorb the power. One set of experiments were made
more » ... were made non-condensing, and one set condensing. I n the latter case communication was made with the condenser of a factory engine, so that the air-pump discharge of the experimental engine could not be measured. The feed-water was carefully measured in all the trials, and indicator diagrams were taken frequently from both ends of the cylinder. The arrangement of the gas-jets was necessarily somewhat imperfect; but every care was taken to ensure accuracy in recording the results. Several experiments were made both with and without the condenser, and with and without the gas-flames. When using the gas-flames the quantity of gas burned was varied. The Bunsen burners were placed quite close to the cylinder externally, and the flames reached about halfway round the cylinder. External radiation was prevented, as far as possible, by sheets of asbestos, the products of combustion passing away through holes left in these sheets. The expansion was constant in all the experiments, as there was no separate expansion-valve. Results of the Experiments.-These are given in the Tables below. It will be seen that the temperature of' the cylinder wall when the gas-flames were used was generally much above that of thc steam admitted. There is a decided economy of steam when the gas-flame jacket is used, but against this must be set the cost of the gas used. This Downloaded by [ UNIVERSITY OF IOWA LIBRARIES] on [16/09/16].
doi:10.1680/imotp.1889.20728 fatcat:bujei5lwkfbtdbjn6yzkth4w2u