The Works Of Messrs. Schneider And Co.

30 MESSRS. SCHNEIDER AND CO’S WORKS. necessary, bas been suppressed, and the fiâmes pass direct into the tubes. In order to facilitate cleaning, these, and the tube-plates, are so arrangée! as to be easily removed. The gas conduit connectée! with the principal underground coJlector, is branched so as to meet each of the boilers of a group, but before the point of division, a valve is introduced by which the gases can be entirely shut off ; by this arrangement the boilers can be stoppée! at will for cleaning and repairs. The tubes require cleaning but seldom, because very little residue is deposited on them. At the present time, the installation consists of six boilers only, but four more will be shortly set up ; of these boilers, eight will be kept in steam, and two will be held in reserve. The principal dimensions of the boilers are as follows : Tube-heating surface Number of tubes ... Thickness of tubes... Internai diameter of tubes Total cross-section of tubes Volume of water ... ,, steam ... Regiatered working pressure 200.00 m2. 125 2152.86 sq. ft. 125 4.25 mm. .165 in. 90.00 mm. 3.54 in. .79 m'2. 8.5 sq. ft. 12.00 m3. 428.8 cub. ft. 5.00 m3. 176.58 „ 7 kilos. 99.56 Ib. per sq. in. As these boilers have only been in operation for a short time, and as the plant is not yet completed, it is not possible to give data based on prolongée! results, but it would appear that the evaporation is not less than 2.5 tons per boiter and per liour, which corresponds approximately to the production of 1 1b. of steam for each pound of coal charged into the ovens. In any case, the addition of these waste-heat boilers to the gas-fired tubular boilers of the blast-furnaces, has effected a very considérable economy. When the boilers were started it was thought it would be necessary to clean the tubes at least once every twenty- four hours. It was soon found, however, that the fiâmes deposit hardly any soot, and tube-cleaning once a week is more than sufficient to maintain the boilers in perfect condition. In order more fully to illustrate the system of collecting the gases, and the arrangement of the boilers, a cross-section of the plant, Fig. 74, Plate XVI., is added. The steam now generated is sufficient, not only for the service of the blast-furnace plant, but also for the steel works department, and for a large part of the construction shops ; these departments are situated not far from the blast-furnaces. When the boiler plant is completed, the steam-generating plant will consist of thirty gas-fired tubular boilers burning the waste gases from the blast- furnaces, and ten coke-oven boilers. This plant will enable the Blast-Furnace Department to supply to the other departments of the works, 36 tons of steam per hour equal to about 2,000 horse-power. Fig. 75, Plate XVII., is a front view of a battery of the boilers just described. The boilers being placée! on the blast-furnace loading platform, as well as on the ground level, a complété system of distribution was required to convey the steam to the varions departments. As the distances involved are very extensive, efficient means had to be devised to reduce condensation. Varions protecting coverings tried, such as silicate cotton, plastic compositions, &c., not having given good results, besides being very costly, Messrs. Schneider and Co. experimented with a mortar formed of granulated slag mixed with soot taken from the boilers or Cowper stoves. This compound is laid on easily with a trowel, in thicknesses varyingfrom in. to 2| in., accord- ing to the size of the pipes. It is then wound round with felt, and a slieet-steel covering is fitted over the felt for such pipes as are in the open, this casing being replaced by a cloth wrapping where the pipes are sh'eltered by buildings or shops. This inexpensive method is found to answer admirably, the temperature of tlie outside of the pipes thus protected being little higher than that of the sur- rounding air, so that condensation is reduced to a minimum. The whole of the blast-furnace and coke-oven plants, machinery, boilers, engines, &c., were designed and con- structed by Messrs. Schneider and Co. in their works.