MORE ECONOMICAL.

Putaruru Press, Volume VI, Issue 268, 24 December 1928, Page 3

MORE ECONOMICAL.

PULVERISED FUEL FOR STEAMSHIPS.

It would appear that the possibility of securing a substantial economy in the fuel account by the firing of steamships with pulverised fuel is beginning to be taken quite seriously. A few months ago the s.s. Mercer, of the United State® Shipping Board, was the only vessel at sea fired by pulverised fuel, but Since then other vessels have been fitted with the necessary installation for the preparation and utilisation~of pulverised fuel and it is -even stated that .one of the companies operating a passenger service between Great Britain and Argentina proposes to accelerate its service by having recourse to the pulverised coal method of firing. With reof powdered fuel the following statement by the Duke of Montrose, briefly but plainly outlines the position gard to the general scope of the use and prospects. One of the prime needs of man today is cheap and swift mechanical transport, either electrically or thermally driven, on land and sea or in the air. At present the mobility of electrically driven vehicles is limited, and we depend upon thermal power, thus necessitating the consumption of. either coal or oil fuel. Coal for many years had the monopoly in power production by the conversion through heat of water into steam, and in 1857 the total worjd’s production of petroleum oil was only 282' tons as compared with 145 million tons in 1926. For purposes of transport coal is rapidly being supplanted by oil, to the detriment of those countries, a large portion of whose wealth lies in their coal deposits. It is, however, a fact that coal is still the cheapest fuel on the basis of British thermal units purchased per £1 sterling, and the reason it is being ousted by oil is largely because of the facilitly with which oil can be handled and burnt in comparison with coal. For marine purposes oil is burned either under ‘he boilers (a wasteful way of usin oil) or for internal combustion engines. Coalis burned under the boilers in conjunction with reciprocating engines or turbines. Now, it may be borne in mind that oil burned as fuel “is only essential for the internal combustion engine, and that the internal combustion engine is only essential for motpr vehicles and aircraft; further, the greater the use made of oil for nonessential purposes, the more this country is dependent on a foreign product. The gross tonnage of new vessels launched in 1927 showed: Coal fired, 297,948; oil fired, 275,889. oil engines (the motor ship), 393,225; whilst the gross tonnage afloat in the same year came to: Coal fired, 40,415,719; oil fired, 18,481,759; the motor ship, 4,270,824.

It is unlikely, except for naval purposes, that there will be any increase in oil fired vessels, and the great fight for supremacy will be between coalfired vessels and the motor shipu. For years past there has been a steady improvement in the engines that use steam; the invention of the steam turbine—geared, exhaust land otherwise—was a great step forward in engineering practice. Simultaneously came the demand for increased boiler efficiency, and the advent of high pressure super-heated steam has made out a case for the use of water tube boilers fjor marine purposes. Obviously, such boilers must he worked under the highest conditions of combustion efficiency, and it follows that the ancient system of hand firing must be abandoned.

What are the alternatives ? Fuel oil burned under the boilers is, as already pointed out, extravagant and unlikely to be continued, and mechanical stokers are being used with success, but I venture to prophesy that in the near future hand firing, mechanical stokers and fuel oil will have to give way to pulverised coal either raw or in the form of residue from a coal distillation plant. When that time comes, and it cannot be long, the motor ship will indeed have to look to its laurels.

I was privileged recently to see an ordinary Scotch marine boiler burning powdered fuel, and I confess to have been amazed at its efficiency. As far as appearance went it might have been fuel oil I saw burning; there was neither smoke nor dust, and as all the 'ash was recovered none came out of the funnel to blow about and bte a nuisance. The boiler, under ordinary conditions, burned 4601 b of coal per hour when hand fired, and had an efficiency of 60 per cent. Under the. pulverised fuel system the amount of similar fuel consumed was 3301 b, with an efficiency of 80 per cent. Granted that technically all difficulties in burning powdered fuel have been overcome, there remains the acid test of cost, and 1 have examined figures which pijove conclusively that

here again the motor ship is beaten. As in the case of all new processes, there are still many details to work out, and prejudices to be overcome. In the first instance, pulverisers will probably be installed on board the vessels so that there will be no econnomy in bunkering, but I am convinced that in the future pulverising will be carried out at depots, and ships will be bunkered with powdered coal pumped through pipe lines as is the case with oil fuel to-day. In this short article I have dealt chiefly with pulverised fuel for marine purposes, but I also look forward to seeing the locomotives of this country driven by jlowdered fuel stored in tank wagons and pumped into the furnaces of locomotives like oil, whilst for factories and furnaces there is for powdered fuel an almost illimitable field.