The Use of Steam to Supplement the Charge.
Page 4
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Anything which will get better results out of the fuel employed is of interest at the present time, when we are all about to be limited to a regulation supply. of petrol. The "Forward Vaporizer" introduces no hitherto unthought-of principle, but it puts into commercial shape for the first time a means of doing what has frequently been suggested may be a desirable feat. This is the admission ofowaters in the form of steam into the cylinder with the charge. Experiments have frequently been made -with this object in view, and various conclusions have been arrived at, mostly, if I remember aright, favourable rather than otherwise, but hitherto no satisfactory means of putting it into fit shape for commercial operation has been devised. The Oxygenerator however, is,now a standardized construction, being supplied in no fewer than 22 different modifications to suit the construction of as many of America's most popular automobiles, whilst the Forward vaporizer, which is being put on the market by a Birmingham firm, is also now obtainable in commercial form.
Description; Claims of Material Economy and Flexibility as Well as Diminished Carbonization.
In the main the device consists of a tank of water which is boiled by contact with the hot exhaust pipe, and the steam so produced is superheated by passing it through a coil also suiroundingothe exhaust pipe and conveying this superheated steam into the cylinders along with 'the fuel. Hot' air is also admitted with the steam—if there is no water in the tank hot air only is introduced—as there is both an .inlet and an outlet valve on the tank, the former open to the atmosphere. The effect of the superheated air and steam entering the manifold and traversing it together with the fuel vapour is to prevent condensation of fuel and the entry into the cylinders of any liquid particles, and as carbonization is largely due to the presence of fuel in liquid form, or in superabundance, it is claimed that carbonization is entirely prevented. Furthermore, as fuel is thus not wasted, a saving in consumption is claimed of from 15 per cent. to 20 per cent, and the presence of the steam is said to break up and eject any carbon which may already be there.
B22 Less Vibration, More Speed.
Then, as regards the action of the steam the theory is that, by its use, the sudden blow of the explosion of the charge is softened, on account of the heat generated Thy it expanding the steam, which continues the pressure on the piston some distance further than the,point where the curve of pressure normally begins to fall off. This results in an increase in power, a 15 per cent. to 25 per cent, improvement being claimed. Vibration, due to the sudden impulses, is lessened, and a speed increase is claimed on this account,but this point, of course, does not interest commercial-vehicle users greatly.
A very considerable increase in engine flexibility is claimed, .as proof of which, it is stated that a sixcylinder touring car, which would run throttled down at 44 m.p.h., with a good deal of popping and missing at that, when fitted with the injector travelled smoothly down to 24 m.p.h. on the high gear. Moreover, the same car was taken, with the throttle so set and a full load, over a 1-in-10 grade, and it surmounted that grade at so slow a speed that the speedometer showed no movement.
American and English Devices Compared.
The American and the English devices are similar, but the latter has no central safety valve, and the steam and hot air enter the manifold at a single point immediately above the carburetter, the U.S. device,os shown, employing a three-way union and connecting up with the manifold as near the engine as possible. The cost. is small, and it may be worth a trial in these days of fuel shortage and expense. The superheated air, it may be further mentioned, enables the more ready use of low-grade fuels and mixtures, which is another desirable feature.