442 TRANSACTIONS OF SECTION B. 
melting (owing to its larger hydrogen and lower carbon monoxide content) as 
that produced with a steam-saturation temperature of 50° C. Thus a plant 
capable of gasifying 250 tons of coal per week would cost about £20,000, but 
the profit on the ammonium sulphate produced (reckoned as selling at £13 10s. 
per ton) would be about 4s, per ton of coal gasified, after providing for labour, 
acid, stores, and repairs, cost of handling sulphate, and interest and depreciation 
at 125 per cent. per annum. 
In generating a gas specially for open-hearth steel furnaces, or for glass- 
melting furnaces, a blast steam-saturation temperature of 50° to 55° C. is 
undoubtedly the best,* but under such conditions the amount of ammonia 
recoverable would be very small. Probably the best steam-saturation tem- 
perature, if ammonia recovery be considered in conjunction with suitability of 
the gas for furnace purposes, would be somewhere about 65° O., which would 
permit of a recovery of about 45 lbs. of sulphate per ton of coal gasified ; more- 
over, in the ammonia recovery process, the plant for which might be simplified, 
the gas would be cleaned before delivery to the furnace, an advantage which, 
7 the author’s opinion, outweighs the loss of sensible heat involved in cooling 
the gas. 
The design of gas producers has been considerably improved in recent years 
by the successful introduction of mechanical contrivances for the automatic 
and continuous remoyal of ash, such as revolving grates. Claims have been 
made that the substitution of a revolving for a fixed grate favourably affects 
the chemical composition of the gas generated, but this is doubtful; the chief 
advantage derived from the use of such contrivances, apart from labour saving, 
probably lies ‘in the constant movement imparted to the fuel bed which 
diminishes the tendency to clinker and facilitates the proper settling down of 
the charge. Whether the increased capital outlay demanded by the installation 
of these mechanical devices would be justified by the saving of labour and 
improved working conditions undoubtedly effected will in each case depend upon 
the type of fuel used, the amount and composition of the ash, and other local 
circumstances. 
The cost of generating ‘ammonia recovery-producer gas of net calorific 
value 145 B.Th.U.s per cubic foot from coal at 15s. per ton would probably be 
about 1d. per 1,000 cubic feet, or equivalent to coal gas at 4d. per 1,000. Mr. 
H. A. Humphrey, in a recent paper upon the ‘ Generation and Distribution of 
Producer-Gas in South Staffordshire’ (the South Staffordshire Mond Gas Co.), 
said that the average price at which Mond gas, generated at the central station 
at Dudley Port, Tiplin, and distributed in mains over an area of 123 square 
miles, is sold to consumers is 13d. per 1,000 cubic feet, or equivalent to town’s 
gas at 7d. per 1,000, a figure which promises well for the future of such schemes 
in areas of similar industrial concentration. 
5. The Utilisation of Blast-Furnace and Coke-Oven Guses in Steelworks. 
Among recent developments in large scale fuel economics perhaps the newest, 
and by no means the least important, is the utilisation of blast-furnace and coke- 
oven gases in iron- and steel-works, both in this country and on the Continent. 
The long discussion which followed a paper on the subject by Mr. E. Houbaer 
at the recent meeting of the Iron and Steel Institute at Brussels revealed how 
much is being done, under scientific guidance, to wipe out the reproach of 
wastefulness of fuel in this branch of industry. I have had the privilege of 
long association with the Skinningrove Iron Company, in the Cleveland district, 
where, under the direction of my relative, Mr. T. C. Hutchinson, much pioneer- 
ing work has been done in recent years to achieve the utmost fuel economy, and 
T am indebted to him, as well as to Mr. Houbaer’s paper, for most of the infor- 
mation which I propose to bring before you. 
In times past—and not so long ago—when the blast-furnace plant was isolated 
from the coke-ovens on the one hand and the steelworks on the other, coke was 
manufactured at the pit-head, in the old wasteful bee-hive ovens, and then 
transported by rail to the blast-furnaces. The pig iron was subsequently con- 
verted into steel, and the latter rolled into girders, plates, rails, &c., at a 
* Wor a full discussion on this point vide a lecture on ‘ Producer Gas with 
Special Reference to Steelworks Requirements,’ by the Author, in Journal of 
West of Scotland Iron and Steel Institute, 1911, 18, pp. 144-173. 
