The Vaporizing Of Paraffin for High-Speed Motors
(Electric Ignition Type)

54 VAPORIZING OF PARAFFIN. mixtures, especially when used in large cylinders : According to the writer’s experience, the methocl of regu- lating the temperature of the vaporizer as shown in Figs. 41 and 42,. is best for engines of moderate size, when using paraffin of specific gravity 780 to 830, altliough a similar effect can be obtained either by the injection of a water spray, which is the method most favoured, or by diluting the mixture with inert gas ; but after ha ving tried each methocl in combination and separately, the writer has arrived at the coriclusion that the temperature of the vaporizer should be maintained as nearly as possible constant for all loads ; that when running at less than half-load the whole of the exhaust »should be passed through the vaporizer ; that at full load, from one-third to one-half the volume. according to size of cylinder, should be diverted direct to the muftier, in addition to which a slight diluent of inert gas, equalling from 5 to 10 per cent, of the total volume of the air supply, should be fed into the mixture in the case of engines ha ving cylinders exceeding 8 to 10 inches dia- meter ; the most suitable amount of suppressing medium is obviously influenced by the temperature of the circu- lating water, the thickness of the walls, and formation of the combustion chamber. The clegree of compression is important also, the lower this is, the quieter the ex- plosive action, but, of course, is not economical in fuel consumption ; thus, compressed-air atomizer vaporizer engines, as per Fig. 36, which were constructed to work with compressions ranging from 40 to 45 Ibs., ran very smoothly without any suppressing medium. With higher compressions, not only are the temperatures higher, but less spent gases are retained in the clearance space.