PLANNING AND LAYING OUT OF GAS WORKS
25
breakdown, etc. There is, of course, always a göod deal of flexibility with a coal-gas plant. For instance, the coal gas yield could be stretched a further 500 cubic feet per ton of coal, the falling off in quality being made up by a slightly lieber gas from the complete gasification plant, or a little more oil in the carburetted water-gas plant. The whole, of course, is essentially a question of relative economy.
ESTIMATED COST FOR A 500-MILLION WORKS
In drawing up specifications for a gasworks of some definite capacity it is in-variably the practice to put down apparatus of a sufficient size to take up future requirements.
In the following estimate, however, this has not been done, for it is desired to show the reasonable cost of producing and distributing about 500 million cubic feet per annum—th.e expenditure on a works having its apparatus designed with. a view to dealing with. an output of an additional 20-40 per cent, cannot be taken as exem-plifying the minimum outlay. For this reason the flgures will probably be con-sidered by some as being on the low side.
It is assumed that about 25 per cent, of water gas will be made, on the average. .All costs include foundations, and relate to average conditions such, as prevail at the present day. It will be appreciated, however, that any endeavour to standardize costs under prevailing conditions is a most unsatisfactory task, and the author includes the following table merely as an illustration and approximate guide as to how the total expenditure is absorbed.
£
per ton of coal
£
per mouth-piece.
£
£
per therm produced
per max. per max. day. day.
Land
Horizontal Retort Bench Foundations, Flooring, all Iron-WORK AND Accessor-IES
1 -J acres per 100 millions per annum, or 3| acres per million per diem. 7 acres at £700
Settings of “ tens ” suitable, 20 feet retorts (i.e. five tiers of two) as occupying least ground space. Assume “ make per mouth-piece ” 9,000 cubic feet per diem. machine charging.
Carried forward
4,900
£ 4,900
22-3 39-2 0-58
39-2 0-58