Liquid Fuel

Abstract

“LIQUID Fuel and its Combustion” was the title of a paper read by Prof. J. S. S. Brame, on February 20, before the Institution of Petroleum Technologists. Attention was directed to the increasing use of liquid fuel, and especially to its connection with those developments of the internal cornbustion engine which have so largely determined the progress of aviation and submarine navigation. Nevertheless he recalls the warning of Redwood (1905) that no oil supplies are in sight sufficient to replace anything like the bulk of solid fuel consumed. The use of liquid fuel for steam raising and industrial heating is the special subject of the paper, and the following considerations are brought forward. In constancy of chemical composition, whatever the source, and therefore of calorific value, mineral fuel oils compare very favourably with coal, and accordingly physical considerations such as low viscosity and freedom from grit may decide the choice of oil fuels. Turning to our home supplies, it is gratifying to note that the heavy fractions of the Scotch shale oils are ideal in this respect; having been distilled they are clean, while their fluidity is very satisfactory. Another home product, which is deserving of the close attention of liquid fuel experts, is coal-tar, the supply of which must increase with the extension of coal carbonisation. Its production may outgrow its uses in normal channels, and as a home-made liquid fuel its rational utilisation is a matter of high national importance. Nevertheless, for marine purposes tar (and tar oils) must remain inferior to petroleum, since a higher oxygen content and lower calorific value are inevitable, while a capacity for giving off disagreeable fumes may make it objectionable in the confined space of a stokehold. Methods of burning oil are surveyed historically, leading up to the spray burners now almost invariably used which atomise the oil.