US676643A - Manufacture of open-hearth steel. - Google Patents

Description

No. 676,643. Patented lune I8, |90l.

` S. T. & C. H. WELLMAN.

MANUFACTUBE 0F OPEN HEARTH STEEL. (Application led Sept. 22, 1900.)

(No Model.) 2 Sheets-Sheet l.

No. 676,643. Patented lune I8, 190i. S. T. & C.'H. WELLMAN.

MANUFAGTUBE 0F OPEN HEARTH STEEL.

(Application led Sept. 22, 1900.) (No Model.) 2 Sheets-Sheet 2.

Wma-s:- fgm X-M @ZY/MM UNITED STATES PATENT -EETCE i SAMUEL T. IVELLMAN AND CHARLES H.k WELLMAN, OF CLEVELAND, OHIO, ASSIGNORS TO IVELLMAN SEAVER ENGINEERING COMPANY, OF SAME PLACE.

MANUFACTURE OF OPEN-HEARTH STEEL.

SPECIFICATION forming part of Letters Patent N0. 676,643, dated June 18, 1901.

Original application iled July 16,1900,v Serial No. 23,810. Divided and this application filed September 22,1900. Serial No. 30,781. (No model.)

To @ZZ whom. it may concern.:

Be it known that we, SAMUEL T. WELLMAN and CHARLES H. WLLMAN, citizens of the United States, and residents of Cleveland,

Ohio, have invented certain Improvements in the Manufacture of Open-Hearth Steel, the same being a division of the invention forming the subject of our application, Serial No. 23,810, Iiled July 16, 1900, and the following to being a specification thereof.

One object of our invention is to facilitate and cheapen open-hearth steel manufacture, an object which' we attain by tapping off the molten steel directly from the furnace into I5 an ingot-mold or other receptacle, then running the slag back into the furnace to be reheated, and then pouring the same into a slag-car, in which it can be conveyed to the dump while still in molten condition, thereby 2o saving considerable labor which is now required in the handling of the slag.

In the accompanying drawings, Figure 1 is a transverse section of an open-hearth furnace constructed for carrying out our invention. Fig. 2 is an enlarged side view of part of the furnace, and Fig. 3 is an enlarged transverse section of the same.

In Fig. 1 the structure 1 may represent any desired form of tipping or tilting furnace pro- 3o vided with end ports cc or other means for causing a flow of the heated gases through the same, the construction of the body of the furnace, the method of mounting the same, and the means employed for tipping or tilting it forming no part of our present invention.

Projecting from one side of the furnace and forming a continuation of the upwardlyinclined side pouring-spout 2 of the same is a tubular casing 3, containing a forehearth 4,

4o which, like the pouring-spout and main bed or hearth 5 of the furnace, is lined with suitable refractory material in order to withstand the heat to which these parts are subjected, this refractory material being either of an acid or basic character, depending upon the character of the furnace to which the invention is applied.

Near its outer end the forehearth 4 has formed in it in the present instance two openings, each of which is normally closedby 5o a plug 6, carried by a pivoted frame or plate 7, hung to the under side of the forehearthcasing and retained in its normal position by means of a key 8, carried by a forked retainer 9, which embraces a projecting portion of said pivoted plate or frame 7, as shown in Figs. 1 and 2.

Through each of the plugs 6 is formed a pouring-opening 10, which is normally closed by means of a stopper 11, consisting by pref- 6o erence of plugs of refractory material strung upon and longitudinally confined to a rod or stem 12, which is secured to and depends from an arm 13, projecting laterally over the structure 3 of the furnace and secured to the 65 upper end of a vertically-movable bar 14., which is guided in a frame 15, pivotally mounted upon brackets 16 on the side of the structure 3, vertical movement of the sliding bar 14 being effected by manipulation of a 7o lever 17, which is hung to a bracket 1S on the frame 15 and is connected to a sliding bar 14 by means of a link 19, as shown in Figs. 2 and 3, the vertical movement of lthe bar 14 being limited by means of a pin 20, which passes through a slot 21 in the bar, as shown in Fig. 2.

Adjusting-screws 22 and 23 at the top and bottom of the frame 15 bear upon the sides of the structure 3 of the furnace and serve i to maintain the guide-frame 15 in its proper 8o vertical position.

When the furnace is in its normal position, as shown in Fig. 1-that is to say, the position assumed when the charge is being melted or treated on the bed 5 of the furnacethe 85 pouring-spout 2 and forehearth 4 project upwardly from said bed at an angle, so that the charge upon the bed of the furnace is wholly within the main structure and under the direct action of the products of combustion 9o therein, no part of said charge entering the pouring-spout or forehearth, which, however, are kept hot by such of the products of eombustion as may enter the same. When it is desired to discharge the contents of the furnace, the same is tipped or tilted until the forehearth occupies a horizontal or downwardly-inclined position. Hence the molten metal will flow into and accumulate in said forehearth and can be discharged therefrom as desired through the pouring-openings l0 in the plugs 6 by proper manipulation of the Stoppers 1l, the discharge being, if desired, directly into the ingot-molds 25, because when the discharge is effected in this way there ,is no likelihood of any outflow of slag with the metal into the molds, the metal always occupying the lower position on the forehearth and the tlow being from the bottom of the latter. In tipping the furnace, as described,

sufficient slag will flow into the forehearth with the metal to provide a protective covering for the latter and prevent loss of its heat, whereby the metal is kept in freely-owing condition until it has all been run off. After the metal has been withdrawn the furnace is again restored to its normal position, so that the slag will flow back onto the b ed of the furnace, and the iiow of the products of combustion through the furnace, which was arrested during the pouring 0peration, is resumed for the purpose of reheating the slag, which has lost some of its heat during the pouring of the steel. When such reheating has been eifected, the removal of the slag can be quickly accomplished by knocking out the key 8, so as to permit the plate or frame 7, carrying the plugs 6, to be swung downwardly, and then again tipping the furnace in order that the slag may escape freely through the openings in the forehearth and into a slag-car or other receptacle run under said hearth to receive it, in which car the slag can, owing to the high temperature imparted to it by reheating, be conveyed while in a molten state to the slagmolten .metal is rendered unnecessary, the labor involved in the handling of the slag in the ordinary way is dispensed with, and the open-hearth steel plant is materially simplied and cheapened. Owing, moreover, to the ready control of the iow of the metal and slag the furnaces may be made much larger than is possible when the usual plan of pouring into ladies is resorted to.

As the forehearth structure 3 of the furnace only receives the metal in limited quantity and for a limited time, said structure can be lighter and more lightly lined than the body of the furnace.

It will be noted that the forehearth is wholly above the level of the charge on the bed of the furnace when the latter is in its normal or working condition. Hence tipping of the furnace is essential to the flow of the molten metal or slag into the forehearth.

Having thus described our invention, we claim and desire to secure `by Letters Patent As an improvement in the manufacture of open-hearth steel, heating the metal and slag together on the bed of a furnace, tilting the furnace to permit the metal andja protective covering of slag to ilow into a forehearth structure thereon, withdrawing the metal from said forehearth from beneath said protective covering of slag but retaining the slag therein, running the slag back onto the bed of the furnace by restoring said furnace to its working position, reheating ysaid slag on the bed of the furnace, and then again tipping the furnace so as to pour the slag therefrom, substantially as specified.

In testimony whereof we have signed our names to this specification iu the presence of two subscribing witnesses. Y

SAMUEL T. WELLMAN. CHARLES H. WELLMAN. l/Vtnesses:

C. W. CoMsrocK, HERBERT T. GLIDDEN.

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