Spons' dictionary of engineering, civil, mechanical, military, and naval Volume 6 ; with technical terms in French, German, Italian, and Spanish

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1874 Excerpt: ...A heat such as we have described will be ready in sixty minutes. The piles are then grasped by a pair of heavy tongs, Fig. 4514, and dragged on to a carriage, Figs. 4515 to 4517, for conveyance to the rolls. The drawing out, charging a fresh heat, and repairing the bottom, will average sixteen minutes a heat. Piles of this size weigh about 4 ewt. eaoli. At this ram, a heating furnace will work thirty-six piles in the twelve hours, or 83 tons of iron a week. For the smaller sizes of merchant bars the piles are made about 18 in. long, 3 in. wide, and 2 J to 3 in. thick. The heat is composed of sixteen or eighteen piles, which take from twenty-eight to thirty minutes in reaching a welding heat. The time occupied in drawing out the heat, recharging, and repairing, averages twenty-one miuutcs. A furnace upon piles of such a size working at this rate heals about 31 tons weekly. The smallest sizes of bars are rolled from solid bolts of manufactured iron, termed fofltfj, measuring 12 to 20 in. long by 1J to 1? in their diameter. Smaller heating furnaces are employed, and from twenty-five to thirty billets are heated at once. To economize time and reduce the waste of iron, which otherwise would be very great with the smallest sizes, cold billets are charged nearly as fast as the hot ones are withdrawn. Furnaces working on billets for guide iron heat from 15 to 25 tons a week, according to the size of the finished bar. The loss of weight during the heating process is dependent chiefly on the skill of the bailer. With care and a fair average quality of iron the loss will not exceed 80 lbs. a ton on the large piles, 130 lbs. on the smaller sizes, and 210 lbs. on the guide-rolled iron. The yield or consumption of puddle-iron to produce one ton of finished iron is ordina...