TRANSACTIONS OF SECTION B. 44] 
using, in furnace work, specially designed burners on the injector principle 
sufficient air can be drawn in with the gas for perfect combustion, with resulting 
marked economies as compared with the older low-pressure burners. The gas is 
being used for aluminium and brass melting in crucible furnaces, for the firing 
of ‘glory holes’ in glass-works, for annealing furnaces, and other similar pur- 
poses. But with the utmost that can be expected from the developments of 
high-pressure distribution in industrial areas, the uses of town’s gas at even 1s. 
per 1,000 cubic feet would still be limited to comparatively small scale 
operations. 
3. Water Gas. 
For all large scale operations, industrial establishments must rely upon 
cheap gaseous fuel generated from raw coal or coke on the spot, or in proximity 
to the works, such as coke-oven gas, blast-furnace gas, producer gas, or water 
gas. For operations demanding a gas of high calorific intensity, such as steel 
welding, where regenerative appliances cannot well be adopted, ordinary blue- 
water gas is admirably suited. With coke at 12s. per ton, the cost of making 
blue-water gas of about 290 B.Th.U.s per cubic foot would be about 4d. per 
1,000 cubic feet (inclusive of fuel, wages, interest, and depreciation), or, say, 
equivalent to coal gas at 8d. per 1,000. With the recent higher price of coke, 
the cost would probably be nearer 5d. per 1,000 cubie feet, or equivalent to coal 
gas at 10d. per 1,000. A modern water-gas plant will yield about 35 cubic 
feet of gas at N.T.P. per lb. of carbon charged into the generators, and about 
60 per cent. of this carbon will appear in the gas. The ratio of the net calorific 
value of the gas to that of the coke charged is about 0°70. It should be noted 
that, despite its much Jower ‘ calorific value,’ water gas has a higher ‘ calorific 
intensity’ than coal gas, and this fact, combined with its lower cost, has 
established its position in regard to steel welding and the like; the construction 
of the burners used in such operations is generally faulty and much gas is 
wasted in consequence. 
4. ‘ Producer Gas.’ 
Where a cheap gaseous fuel has to be specially generated in situ, the com- 
plete gasification of solid fuels by means of a mixed air-steam blast, with or 
without ‘ammonia recovery,’ is usually the method adopted. The gas obtained 
contains some 35 to 45 per cent. of total combustible constituents, and its com- 
position (assuming an ordinary bituminous coal to be the raw fuel) varies 
between the following wide limits, according to the relative proportions of steam 
and air in the blast :—* 
Steam saturation, temp.C.° . . . . . . 50° .. 85° 
Per cent. CO, : é ; : : : eT a2io") 3 : 16.0 
of { Co 0 : A : : 5 : «00D. a 12-0 
composition 4 H, eee meee Saree A SOE ee Lr eee tS Z6-0 
of the | Crmeh aware, MEE Ik. coal A MASE ISO ke ics ck 
dry gas. \N, Se Unsseateee Gd et 24Na Wie sol Tit adiows (43-0 
Per cent. of total combustibles. Ned ; et te 408i: . 41:0 
Net cal. value B.Th.U.s per cubic feet at N.T.P. .  . 169 : : 145 
Approximate yield of gas, cubic feet at N.T.P. per 
ton of coal Mee AS yy th. eee ee te TasO0On x1 2 145,000 
So high a steam-saturation temperature as 85° permits of a large recovery of 
the nitrogen of the coal as ammonium sulphate (90 lbs. per ton of coal gasified), 
but the initial cost of an ammonia recovery plant is still a serious consideration, 
and the gas is not nearly so well adapted for such operations as steel or glass 
the year ending March 31, 1913, was 1,900 million cubic feet at an average price 
of 1s. 34d. per 1,000 cubic feet. 
* For full information on the chemistry of the gasification and the influence 
of varying proportions of air and steam in the blast upon chemical composition 
of the gas and the general efficiency of the process, vide Bone and Wheeler, 
Journ. Iron and Steel Institute, 1907, I., 126, and 1908, II., 206, f 
