US522034A - Manufacture of steel - Google Patents

Description

UNITED STATES- PATENT OFFICE.

BENJAMIN TALBOT, OF PENOOYD, PENNSYLVANIA.

MANUFACTURE OF STEEL.

srncrmcn'rron forming part of Letters Patent No. 522,034, dated June 26, 1894.

Application filed March 23,1894. Serial No. 504,761. (No specimens.)

To all whom it may concern.-

Be it known that I, BENJAMIN TALBOT, a subject of the Queen of Great Britain and Ireland, residing at Pencoyd, county of Montgomery, Pennsylvania, have invented certain new and useful Improvements in the Mannfacture of Steel, of which the following is a specification.

My invention relates to the manufacture of steel and particularly to anvimprovement in the method of charging open hearth furnaces whereby considerable saving of time in this step in the manufacture is effected, with a consequent economy in the production of such metal.

It is the custom generally, in the makingof steel by the acid or basic open hearth process, to use pig iron and scrap as the material for the charges in the Siemens furnace in whichthe said material is to be melted and converted into steel. This scrap consists of various kinds and shapes of steel or iron, such as crops of blooms, rails, bars, angles, plates, sheets, &c., and is charged separately from the pig iron. Such a miscellaneous material both in form and weight when used in its ordinary condition for charging consumes a great amount of valuable time in the introduction into the furnace as it is now invariably charged by being thrown or pushed in by men in small quantities. This operation being so tedious and slow it is at once apparent that with furnaces of large capacity it takes several hours to charge them and that the furnace necessarily cools down very much while the doors are open allowing a large quantity of cold air to be drawn into the furnace thereby reducing itstemperature materially. To overcome these objections I propose by myinvention not only to standardize the scrap charges so that they may be readily introduced into the furnace with the least possible loss of time, but I also efiect a further saving of the heat by raising the temperature of the cold scrap while preparing it for charging. It is of course obvious that the saving of this heat which wastes during the process of charging as now practiced, results in a saving of the fuel, and the decrease in the time required for making a charge with this saving of heat, W111 necessaute materially to reduce the cost of production.

In carrying out my invention I take the scrap which consists of various kinds and forms of decarbonized metal, hereinbefore stated, and place it in a suitable mold, pour-- rily increase the output, all of which contribmoved from the mold. and transported to the i open hearth furnace and introduced into it by suitable charging devices preferably while the block is'in a heated condition. The liquid metal as it mingles with the scrap imparts thereto while solidifying a sufficient degree of heat to raise the temperature of the scrap to a red heat. When the block is charged in this condition a less amount of heat is required in the subsequent melting down and conversion into steel, thus saving fuel.

Any suitable form of mold may be used for the purpose of casting the ingot or block, but I prefer to cast it in a mold made of four plates clamped together so as to form a flask or mold of the shape of a truncated, quadrangular pyramid, with the base resting on an iron bottom plate forming the mold bottom, thereby renderingit easy to lift the flask from the block or ingot after the metal has sufiiciently set to bind the scrap together. As soon as the metal is set at the outside edges, the

clamps should be loosened because the cold metal in heating expands, bringing considerable pressure on the mold and making it difficult to remove the same at the proper time.

I am aware that it has been proposed to bind the borings and turnings of machine shops with molten iron for the purpose of forming a protecting envelope of these fine scraps in order to insure their melting in ordinary furnaces where they would otherwise be burned without melting to form iron; but my invention differs from this in that its object is to standardize larger separate pieces of scrap of decarbonized metal, such as hereinbefore mentioned,so as to make a charging of the open hearth furnace less tedious and slow, with a resulting increase in the output and in the consequent economy in production.

I may state that I have used in practice an ingot about five feet long, eighteen inches wide at the bottom, tapered to fifteen inches at the top, and twelve inches thick, with a weight of between three thousand five hundred to four thousand pounds, but such dimensions maybe varied within certain limits as desired. It will be readily seen, therefore, that by using an ordinary charging machine, blocks of this size can be rapidly introduced into the furnace and a great amount of time and labor heretofore spent in this operation is saved as above stated.

I claim as my invention The herein described improvement in the manufacture of steel which consists in standardizing the scrap charge for open hearth f urnaces by casting the scrap with liquid cast iron in suitable molds forming blocks of uniform size and removing the mold when the liquid iron has set and bound the scrap, and