Producer Gas Practicable for Light Vans
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THERE is not the slightest reason why the use of 1 producer gas should be limited to large and moderatecapacity vehicles. Evidenceof this is afforded by a conversion of a Ford 8 h.p. car carried out by Gilfords (H.S.G.), Ltd., 74, Victoria Street, London, S.W.1, which performed excellently in our hands during a run of about 18 miles
To avoid a 30 per cent, loss of power, the original 8 h.p. engine has been replaced by a 10 h.p. unit, and to afford the required compression ratio a cylinder head of the former type has been fitted. This has brought the figure up to 7.8 to 1.
The producer, which measures 37 ins. by 10i ins., and attendant apparatus, carried on the back in the case of the car, occupy little space and weigh, empty, Only about
1 cwt. In addition, 90 lb. of by 4, in. anthracite is contained in the hopper. On the car this is sufficient for some 200 miles.
.In point of fact, 25 lb. is the minimum—for this producer —required to keep the fire in good gas-making trim, so the consumption rate is snore like 200 miles per 65 lb., that is, 3 miles per lb. With a greater load, of course, than the normal passengers of an old-type Ford Eight car, the rate would not be so good. , Also, with lighter fuels, the mileage per prOducer-fiill will obviously be lower.
In this Connection the recommended fuel specification is by no Means intolerably rigid. Suitable anthracite is not limited to one sort, we understand; any good low-volatile anthracite with low ash content may be used, and it need not be dry. When low-temperature coke is employed it must be as free from tar as possible and low in sulphur and other impurities.
Satisfactory running is afforded by charcoal and we are inforthed that a suitable type is marketed by Messrs. Shirley Aldred, of Worksop. It is described as type Lf, and the price before' the outbreak of war was £.7 10s. per ton. About 12 lb. is said to be the equivalent of one gallon of petrol.
To turn to our impressions of the performance of the vehicle on the road, we detected little difference from the behaviour of the car on petrol. Running from the Kingston By-pass to Wisley, on the Portsmouth Road, and back, we cruised at 40-50 m.p.h., taking hll hills in top gear comfortably, but holding the speed, when climbing, not quite so well as with petrol. .A definite increase in flexibility was observed, there was no pinking, and the engine pulled steadily at low r.a.m, with full throttle. A feature is that better results are obtained when it is possible to avoid sudden alterations of the throttle position. Flicking the accelerator pedal is definitely harmful to• the efficient functioning of the plant.
It is advisable to let the engine run at about twice the normal speed when idling, in order to keep up the temperature of the fire. After a stop of about 10 minutes. a restart was made without recourse to petrol (as for the initial start, which occupied only two minutes), but it necessitated the use of the starter for rather longer than usual and a pause of three or four minutes while proper conditions were re-established in the producer.
Two air levers are provided which require the exercise of a little intelligence in manipulation. The technique of con trol, however, is soon acquired. While driving on the road there is nothing extra to do at all.
Between the producer and the engine are two filters and a cooler. The main filter is designed to operate for about 800 miles without attention. At the end of this period, pressure is released from a pad of sisal fibre and this is disturbed and washed with water. Dirt is also flushed out of the cleaner by similar means. The pad is left to dry and an alternative wad of sisal is substituted. Each weighs about 4 lb, The cooling tube, which has a cap at each end, requires brushing out once every 1,000 miles or thereabouts. Only very occasional attention is required by the final filter, which is of the oil-damped type.
Clinker formation in the producer is no trouble, provided that the ash-content be low. In view of its small size, no special gear is necessary, a rake-out when the fuel is used up being sufficient. To enable low-grade fuels to be used, however, apparatus for lowering slag formations from the fire zone can be fitted.
In' the ILS.C. _system water is introduced into the fire, and a hand -controlled drip feed was provided on the car we tested. Normally, the water supply would be regulated automatically, the valve being interconnected with the accelerator. , The tuyere, by which air is admitted to the fire, is water cooled, pipes running forwards to the engine-cooling system. Gas leaves the producer low down on the front side, crosses the chassis by a cooling tube, deposits its dust in the base of the cleaner, percolates through the sisal and travels forwards by a pipe running along the off-side frame longitudinal.
Under the bonnet it enters the oil-damped filter, and thence, via the mixing chamber, passes to the engine.
One air valve supplies the correct quantity of air for idling and the other permits the required amount of additional air for running. The latter incorporates a device by which the relation of air-valve opening to throttle opening may be varied to compensate for changes in fire-bed resistance, etc. There was no need to adjust eith6r, while running on the road during our test.
To Sum up, this small car affords clear evidence that the light van can be operated satisfactorily on producer gas. Neither too heavy nor too bulkY, the plant, in this diminutive size, functions efficiently. It is not expensive in the first instance, maintenance is simple and not the 'dirty job often imagined, whilst the economy, would justify the employment of solid fuel eVen were there no shortage' of petrol.