The Mechanical Handling and Storing of Material

HANDLING BLAST-FURNACE STOCK 359 a large number of coke cars to be run over the pockets and unloaded simultaneously ; secondly, it obviates the drawback of these large pockets, as the proportion of dust entering the furnace at one time is minimised; thirdly, it is found that by putting the coke through a weighing truck the dust therefrom prevents the ore from sticking to the truck, and thus quickens the discharge. The fact that one man can maintain the furnace shows sensitive and rapidly delivering pockets. The operator need not quit his station for any purpose. He can control either truck or pockets from one position, pendant cords somewhat like a bell-rope being conveniently placed, and by simply pulling the rope he can, in a few seconds, load his car. The load on the car is indicated Fig. 501. Plan of Hoover & Mason’s Ore-Handling Plant. by a hand on the dial. Buttons of different colours are placed on this dial, each button corresponding to a load of ore, coke, or limestone. The operator pulls the cord until the index finger travels to its proper position ; he then releases it, and the charging ceases. In both the 5 and 10 ton grabs the path of the cutting edge through the material and the inclination of the tray follow certain lines which it is claimed have been found most efficient for digging ore. The construction of these grabs permits of the path being altered to suit any given material. It may be of such a character as to make an even cut of 6 or 8 in. below the surface over the area contained in the closing stroke, or a cut to any other depth (within certain limits) that the nature of the material j may