US374558A - Reheating iron and steel - Google Patents

Description

(No Model.) 3 She'ets-Sheet 1. H. ROBERFIS REHEATING IRON AND STEEL. No. 374,558. Patented 1390.76, 1887.'

3 Sheets-Sheet 2.

(No Model.)

H. ROBERTS.

REHEATING IRON AND STEEL.

Patented Deo. y6, 1887.

(N6 Model.)

3 Sheets-Sheet 3.

H. ROBERTS.

REHEATING IRON AND STEEL.

Patented Dec... 6, 1887.

inventan Y NITED STATES PATENT OFFICE.

HENRY ROBERTS, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR OF ONE-HALF TO GEORGE T. OLIVER, OF SAME PLACE.

REHEATING IRON AND STEEL. r-

SPECIFICATION forming part of Letters Patent No. 374,558, dated December 6, 1887.

Application tiled June 23, 1886. Serial No. 205,961. (No model.)

To @ZZ whom it may concern.-

Be it known that I, HENRY RoBERTs, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Reheating Iron and Steel; and I do hereby declare the following to be a full, clear, and exact description thereof.

In the process of reheating iron as heretofore 1o commonly practiced a considerable portion of the iron-say about eight to ten per cent-.has been converted into mill cinder by oxidation, and thus lost.

In heatingfurnaces, using gas as fuel, Where .t5 an excess of air should becommingled withy the gas to produce the best combustion, the excess of oxygen makes a cutting iiame which quickly attacks and oxidizes the iron, and if it be attempted to avoid this by lessening the 2o air-supply the gas is imperfectly consumed and much heat is lost.

The object of my invention is to obviate this evil and toimprove the reheating process by preventing oxidation, and thereby to lessen the Waste and to cheapen the cost of production.

It consists in introducinginto the bed ofthe furnace with the gas and air of combustion a supply of steam, which, while it permits combnstion of the gas, so protects the iron in the workingcharnber as to prevent to a large degree the oxidizing influence of the tlame thereon. By practical experience I have found that the amount of cinder produced is, by the presence of steam, reduced about seventy per cent. The production of the furnace is correspondingly augmented.

To illustrate my invention I show in the accompanying drawings views of aregenerative 4o gas-furnace patented to William Swindell on January l2, 1886, to which my invention is applicable. I premise, however, that I do not limit the scope of my invention toits application to this or any other particular kind of heating furnace, since by proper modifications, such as will suggest themselves to those skilled in the art, the invention may be used with other forms of heatingfurnaces using gaseous fuel.

In the drawings, Figure l is a vertical longitudinal section of the furnace. Fig. 2 is nating at the rear side of the vertical ports c',

a horizontal section on the line A B of Fig. l. Fig. 3 is a vertical transverse section on the line O D of Fig. 1.

' Like letters of reference indicate like parts 55 in each. A

The furnace has abed, a, neck or bridge iues b, double regenerator or air-heating chambers c d on each side, fines or ports e, extending between the bridge-fines b and the upper ends 6o of the regeneralor-chambers c, and flues or ports f, extending between the bridge-fines b and the upper ends of the regenerator-chambers d. The regenerator-chambers c d are designed to be filled with checker-work, and are 6 5l connected with the air-inlet pipes and with the stack by means of the fines or conduits g in the usual manner of reversible regeneratorfurnaces. rIhe waste heat and gases from the bed pass for a while through one pair of chain bers to the stack, heating up the checker-work therein, while the air passes in through the other pair of regenerators. From time to time the course of the currents is reversed, so that the air may be caused to pass through the heated chambers. This reversal is effected by means of reversing-valves, which are 'placed at thejunction ofthe fines g with the airinlet and stack filles.

As the construction and arrangement ofthe reversing-valves and of the air-inlet and stack ilues are the same as in ordinary reversing regenerator-furnaces and are well known, I will not describe them.

At each end of the furnace is a mainv gaspipe, h, controlled by a valve, h', and termivnating in a distributingpipe, i, which has any desired number of branch pipes i', said branch pipes extending through the Walls and termiwhich lead up from the chambers cto the flues e. The walls through which the branch pipes i extend are situate between the vertical ports d', by which the regenerator-chambers 4 d communicate with the outer ends of the fines f.

At each end of the furnace there is a main steam-supply pipe, m, controlled by a valve, m', and terminating in a distributing-pipe, n, which has any desired number of branch pipes n', which extend beside the branch gas-pipes and terminatealittle below the latter. As

IOO

thus constructed, the gasand steam when discharged from the pipes n and i mix with the hot air from the regenerator-chambers c and d and all together pass to the bed a, the gas meanwhile uniting and burning with the air and the steam mingling with the burning and consumed products to form a nonoxidizing bath for the iron on the bed. By means of the valves m the quantity of steam supplied may be nicely regulated. This will of course depend on the amounts and the relative proportions of gas and air used in the furnace; but in any case it will be easy to fix the valve to supply an amount of steam which will permit a sufficient quantity of air to be used to con sume the gas, but will neutralize the oxidizing influence of the air on the heated iron.

In addition to the advantage in lthe saving of iron, my improvement also produces a better article. For instance, in the manufacture of wire rods, for which I have itin daily practical operation, the rod comes from the mill in a bright and polished condition, there being little, if any, black oxide on any portion of its surface. It is necessary before drawingr the Wire rods down into wire to pnt them in an acid bath for the purpose of cleaning or removing the oxide from them. Ordinary wire rods have considerable scale upon their surfaces and require to remain in a strong bath The rodsl` for a considerable length of time. made from billets heated in accordance with this invention, being almost if not entirely free from scale, require but ashort immersion in a weak acid solution, and the result is that a saving of time and acid is effected. Moreover, stronger, smoother, better wire is produced from the rods, because often in former rods pieces of scale would extend into the body of the rod, so that when the rod was cleaned'a weak or defective spot would be found, which, when the Wire was drawn out, caused it either to break at once or produce a a defect in the Wire.

I am aware that steam has been extensively used in the treatment of iron and steel for various purposesfor example, to promote the combustion ofthe furnace, to oxidize the iron, to oxidize the impurities of iron, and in combination with other gases and reagents for similar purposes; but steam has liever before been introduced into a-gasfurnace in the processof reheating iron or steel in such way as to reduce its oxidation. I therefore do not claim the use of steam generally, and I- disclaim the process described in the following Letters Patent: Nos. 88,084, 143, 543, 132,456, 182,457, 273,799, and 284,551.

I claim- As an improvement in the art of reheating iron and steel, reheating the iron or steel in a gas-furnace in the presence of steam, so as to form a non-oxidizing bath, substantially as and for the purpose specified.

In testimony whereof I have hereunto set `my hand this 21stv day of June, A. D. 1886.

HENRY ROBERTS. Vitnesses: f

W. B. CoRWIN, THOMAS B. KERR.

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