The Works Of Messrs. Schneider And Co.

BLAST FURNACE DEPARTMENT: BLOWING ENGINES. 25 cylinders are connectecl by two mains forming pressure chambers, to a general reservoir above, common to the six machines, and from which are taken the service mains that distribute the cold air to the Cowper heating stoves. Each engine can, in case of necessity, be isolated from the reser- voir by means of valves placed on the upper side of the pressure chamber. In order to avoid differences of speed connected to the valve gear, and act simultaneously and independently of each other, without interfering with their proper action on the expansion. Thanks to this arrangement, the engine speed never exceeds the maximum of 54 revolutions per minute and the variation of the air pressure does not amount to 1 centimetre (.39 in.) of mercury above or below the normal pressure. Fig. 54 Fig. 54. Blast-Furnace Department; Installation of Biowing Engines. Pakticulars of Blowing Engines. Diameter of steam cylinder Length of stroke ... Mean steam admission Effective steam pressure at cylinder ... Diameter of air cylinder ... Effective section of cylinder Volume of dead space Number of inlet valves at each end of air cylinder Maximum inlet area Number of outlet valves at each end of cylinder Maximum area of outlet valves ... .750 in. 1.400 ni. .300in. 6 kg. 1.770 m. 2.436 sq. m. 4 per cent. 150 .276 sq.m. 180 .331 sq. in. 29.53 in. 55.12 in. 11.81 in. 85 Ib. 69.6 9 in. 26.3 !) sq. ft. 4 per cent. 150 2.969 sq. ft. 180 3.56 sq. ft. Number of revolutions per minute Weight of fly wheel Air pressure in reservoir (in centimetres of mercury) Maximum depression at inlet (in centi- metres of water) Work absorbed by air cylinders......... ,, developed in steam cylinder Volume of air compressed per revolution at 0 deg., and at .760 metre (29.92 in.) Air compressed at 0 deg. and at .760 metre (29.92 in.) per kilogramme of steam used 50 11,000 kgs. 30 17 288 h.-p. 378 h.-p. 6.06 cub. m. 4.50 cub. m. 50 11 tons 11.81 in. 6.69 in. 288 h.-p. 378 h.-p. 212 cub. ft, 158 cub. ft. and of pressure which are liable to occur in an installa- tion where all the furnaces are in communication, each machine is provided with a double regulator of speed and of pressure. This regulator is a combination of the ordinary centrifugal governor, with an air cylinder con- taining a piston that reçoives, on one side only, the air pressure from the reservoir. These two regulators are which is reproduced from a photograph, is a general view of the installation of blowing engines, showing five engines, the sixth being in course of érection. A large number of machines of this type, as well as vertical blowing engines, have been constructed at Creusot for different metal- lurgical Works in France. Granulating Slag.—Up to the present time, the slag E