US3425676A

US3425676A - Molten metal producing furnace

Info

Publication number: US3425676A
Application number: US491544A
Authority: US
Inventors: Harold F Shekels
Original assignee: United States Steel Corp
Current assignee: United States Steel Corp
Priority date: 1965-09-30
Filing date: 1965-09-30
Publication date: 1969-02-04
Anticipated expiration: 1986-02-04

Description

heet

Hf F. sHEKELs MOLTEN METAL PRODUCING FURNACE Feb. 4, 1969 Filed Sept.

Attorney Feb. 4, 1969 H. F. sHEKELs 3,425,676

MOLTEN METAL PRODUCING FURNACE Filemsepu-a, 1965 Sheet 2 of4 l N vE/v ron. HA ROL o E SHE/rel. s

A f orney H. F. sHEKELs A 3,425,676 f Feb. 4, 1969 MOLTEN METAL PRODUCING FURNACE Sheet Filed Sept. 50, 1965 Feb. 4, 1969 y H. F.SHEKE1 S 3,425,676

MoLTEN METAL PflaonucING FURNACE Filed sep. 30, 1965 Sheet L of" 4 INVENTO?. HAROLD SHEKE'LS BMwm,

United States Patent O 3 425,676 MOLTEN METAL PRODUCING FURNACE Harold F. Shekels, Edgewood, Pa., assignor to United States Steel Corporation, a corporation of Delaware Filed Sept. 30, 1965, Ser. No. 491,544 U.S. Cl. 266-11 13 Claims Int. Cl. C21b 13/14; C21c 5/38, 7/06 ABSTRACT OF THE DISCLOSURE This invention relates generally to `a molten metal producing furnace and more particularly to an improved furnace for producing molten iron for use in a basic oxygen furnace. A basic oxygen furnace is provided with exhaust outlet means for exhaust gases from the basic oxygen furnace. A molten metal producing furnace is disposed adjacent the basic oxygen furnace and adapted t receive a molten metal producing material, and a conduit means is connected to the exhaust outlet means and the molten metal producing furnace, the exhaust gases being operable to melt the molten metal producing material into molten metal. The conduit is operable to selectively engage either the exhaust outlet means or a fluid control means which can provide heated fluids to the conduit and thence to the molten metal producing furnace when the basic oxygen furnace is not producing exhaust gases.

Heretofore basic oxygen furnaces have been of the type shown in the following U.S. patents:

U.S. Patents Nos. 2,644,746, H. Hautmann, July 7, 1953; 2,741,554, R. F. Rinesch, Apr. 10, 1956; 2,741,555, O. Cuscoleca et al., Apr. 10, 1956; 2,789,046, K. G. Speith et al., Apr. 16, 1957; 2,790,712, H. Hendrichs, Apr. 30, 1957; 2,794,681, T. E. Suess, June 4, 1957; 2,799,492, J. Hobenreict et al., July 16, 1957; 2,800,405, R. F. Rinesch, July 23, 1957; 2,800,631, T. E. Suess et al., July 23, 1957; 2,803,534, O. Cuscoleca et al., Aug. 20, 1957; 2,815,275, A. Richter, Dec. 3, 1957; 2,816,018, K. Ziegler, Dec. 10, 1957; 2,850,324, T. E. Suess, Sept. 2, 1958; 2,850,325, T. E. Suess, Sept. 2, 1958; 2,851,351, O. Cuscoleca et al., Sept. 9, 1958; 2,855,194, W. Konig, Oct. 7, 1958; 2,892,699, C. R. Austin et al., June 30, 1959; 2,893,861, R. F. Rinesch, July 7, 1959; 2,978,189, P. L. Metz et al., Apr. 4, 1961; 2,988,443, P. L. Metz, June 13, 1961; 3,000,621, P. Puxkandl, Sept. 19, 1961; 3,004,847, L. J. R. Lambert et al., Oct. 17, 1961; 3,005,- 628, R. F. Rinesch, Oct. 24, 1961; 3,007,691, R. F. Rinesch et al., Nov. 7, 1961; 3,011,773, P. L. Metz, Dec. 5, 1961; 3,028,232, R. F. Rinesch, Apr. 3, 1962; 3,043,470, P. Puxkandl, July 10, 1962; 3,076,703, P. L. Metz, July 5, 1963; 3,083,957, K. Langer et al., Apr. 2, 1963; 3,089,767, R. F. Rinesch, May 14, 1963.

A conventional basic oxygen furnace is first charged with light scrap and heavy scrap and finally with molten pig iron. This molten pig iron is necessarily produced primarily in a blast furnace or, in the case of a nonintegrated steel plant, in a cupola of the type described in the July 1964 issue of Iron and Steel Engineer on pages l89-192. One disadvantage of a conventional basic oxygen furnace is the need for the auxiliary blast furnace and/ or cupola.

After the charging of the .basic oxygen furnace has been completed, the oxygen lance is lowered into the basic oxygen furnace and the blow commences, thereby developing temperatures around 4000 F. and an excess of 300,000,000 B.t.u./ hr. This developed heat is dissipated through a water-cooled hood on the basic oxygen furnace, which hood requires auxiliary cooling apparatus, such as high-powered pumps, cooling towers and a steam-expansion chamber provided with relief valves. From the `above description it will be appreciated that other defects ICC associated with conventional basic oxygen furnaces are the dissipation of the heat developed in the basic oxygen furnace, the requirement for expensive auxiliary cooling apparatus and the attendant high operating cost of the conventional basic oxygen furnace.

The general object of the present invention is to avoid and overcome the foregoing and other diiculties of and objections to prior art practices by the provision of an improved furnace for producing molten metal and a fluid control assembly therefor, which furnace and control assembly therefor:

(1) Eliminate the need for a blast furnace and/or cupola for a basic oxygen furnace;

(2) Substantially utilize and substantially eliminiate the dissipation of the large quantity of heat generated in such basic oxygen furnace;

(3) Partially eliminate the water-cooled hood and related cooling apparatus normally associated With a basic oxygen furnace; and

(4) Substantially reduce the operating costs associated with a basic oxygen furnace.

The aforesaid objects of the present invention, and other objects which will become apparent as the description proceeds, are achieved by providing a basic oxygen furnace provided with exhaust outlet means for the exhaust gases from the basic oxygen furnace and a molten metal producing furnace disposed adjacent the basic oxygen furnace and adapted to receive a molten metal producing material. A conduit means connects the exhaust outlet means and the molten metal producing furnace. The exhaust gases are operable to melt the molten metal producing material into molten metal. The fiuid control assembly has a sealing member in engagement with the conduit means and fluid control means adjacent the sealing member for controlling the flow of fluid through the conduit means.

For a better understanding of the present invention, reference should be had to the accompanying drawings wherein like numerals of reference indicate similar parts throughout the several views and wherein:

FIGURE 1 is a side elevational view of the improved molten metal producing furnace and the associated basic oxygen furnace;

FIGURE 2 is a vertical sectional View taken along the line II-II of FIGURE l in the direction of the arrows showing the interior of the molten metal producing furnace;

FIGURE 3 is a vertical sectional view taken along the line III-III of FIGURE 1 in the direction of the arrows showing the batching bin, swivel hood and conduit means disposed between the batching bin and the swivel hood;

FIGURE 4 is an enlarged fragmentary side elevational view partially in section of the swivel hood and fluid control assembly;

FIGURE 5 is a horizontal sectional view taken along the line V-V of FIGURE 4 in the direction of the arrows;

FIGURE 6 is a fragmentary side elevational View partially in section of a basic oxygen furnace having a rotatable vessel;

FIGURE 7 is a fragmentary View similar to FIGURE l showing an alternative embodiment of the molten metal producing furnace and two basic oxygen furnaces; and

FIGURE 8 is a plan View of the molten `metal producing furnace and basic oxygen furnaces shown in FIG- URE 7.

Although the principles of the present invention are broadly applicable to a molten metal producing furnace, the present invention is particularly adapted for use in conjunction with a molten scrap iron producing furnace and hence it has been so illustrated and thus been so described.

With specific reference to the form of the present invention illustrated in the drawings and referring particularly to FIGURES 1 and 2, a basic oxygen furnace is indicated generally by reference numeral 10.

As shown in FIGURE 1, this basic oxygen furnace is provided with exhaust outlet means, such as the mouth 12, for the exhaust gases. Such basic oxygen furnace 10 is pivotally mounted on bearings 14 mounted on suupporting piers 16 and is oscillatable on the bearings 14 by a drive means, such as the gear reduction unit 18 and motor 20.

After the basic oxygen furnace 10 is charged while in the tilted position (not shown in FIGURE 1) with scrap metal from a charging box (not shown) and with molten pig iron from a hot metal ladle (not shown), an oxygen lance 22 is lowered from an oxygen lance frame 24 through a combination guide and heat seal 26 in a swivel hood 28 (FIGURES 1, 3 and 4) into the basic oxygen furnace 10 to a predetermined position above the surface of the bath by means of a hoist 30, The oxygen is then released from the oxygen lance 22, thus generating about 300,000,000 B.t.u./hr. and temperatures of about 4000 F. in the exhaust gases from the basic oxygen furnace 10. After the oxygen jet is released, slag forming fluxes, such as burned lime, lluospar and mill scale are added in controlled amounts from a batching bin 32 (FIGURES l and 3) through a chute 34 to the basic oxygen furnace 10. A piston 36 of a lluid operated cylinder 38 (FIGURE 3) operates an arm 40 connected at 42 to a door 44 and hence oscillates the door 44 between the left-hand dotted line open position shown in FIGURE 3 and the righthand dotted line closed position shown in FIGURE 3.

A conduit or hood means, such as the swivel hood 28 (which swivels between its solid line position, FIGURE 1, and its dotted line position, FIGURE 1) and a fixed hood 46 (FIGURE 1), connects the mouth 12 to an entrance aperture 48 (FIGURES 1 and 2) in a molten metal producing furnace, such as a scrap metal furnace 50, adapted to receive molten metal producing material, such as scrap metal and pig iron (hereinafter called scrap metal 52) or furnace additions, such as molybdenum, titanium, magnesium, nickel, iron ore and the like. The exhaust gases are operable by conduction, radiation and convection to melt such scrap metal 52 to molten scrap metal 54. I-Iot exhaust gases from the scrap metal furnace 50 exit through exhaust means, such as an exit aperture 56 (FIGURES l and 2) in the scrap metal furnace 50, scrap metal stack 58 and a gas stack 60.

It will be understood that the swivel hood 28, fixed hood 46, scrap metal furnace 50, scrap metal stack 58 and gas stack 60 are lined, for example, with a heat-resistant lining 62, such as a first or outer layer of burned magnesite brick, a second layer of basic ramming mix and a third or inner layer of unlired tar-bonded dolomite, dolomitemagnesite or magnesite bricks. The swivel hood 28 may be water cooled by means of conventional pipes, manifolds and connecting lines (not shown). As shown in FIGURE 1, control means, such as the damper 64, are disposed in gas stack 60 controlling the flow of exhaust gases through and the resultant temperature in the scrap metal furnace 50.

After the oxygen lance 22 (FIGURE 1) has been withdrawn from the basic oxygen furnace 10 and the basic oxygen furnace 10 has been tapped through tap hole 66 into a hot metal ladle 68, the basic oxygen furnace 10 is charged with scrap metal from a charging box (not shown). A tap hole 70 (FIGURES 1 and 2) in the bottom wall of the scrap metal furnace 50 is then opened, thereby permitting the molten scrap metal S4 to pour down supply means, such as a hot metal chute 72, into the now tilted basic oxygen furnace 10, which hot metal chute 72 is provided with a heat-resistant lining and preheated and additionally heated by conventional gas jets (not shown).

If weighing of the charge of molten scrap metal 54 from the scrap metal furnace 50 is required, the molten metal 52'fron1 the hot metal chute 72 is directed to a conventional hot metal ladle (not shown) supported on a scale (not shown), which hot metal ladle is then transferred by crane (not shown) to the tilted basic oxygen furnace 10.

Thereafter, the lance 22 is again lowered into the basic oxygen furnace 10, oxygen is released from the lance 22 andthe slag forming fluxes are added to the basic oxygen furnace 10 from the batching bin 32 as explained above, thus initiating the next heat cycle.

As shown in FIGURE l, feed means are connected to the scrap metal furnace 50 for introducing scrap metal 52 into the scrap metal furnace 50.

Feed means For the purpose of charging the scrap metal furnace 50 (FIGURE 1) with scrap metal 52, such scrap metal 52 is dumped from a truck (not shown) into a scrap car 74 shown in the dotted line position of FIGURE l. The now loaded scrap car 74 is then moved by drive means (such as a motor 76, drum 78, cable and counterweight 82) up an inclined track 84 to its solid line position (FIGURE 1) and the scrap metal 52 is dumped through a now open pivotable entrance door 86 in a scrapmetal chamber 88. The pivotable entrance door 86 is opened and closed by a hoist 90. When the scrap metal chamber 88 is filled, the entrance door 86 is closed and a slidable exit door 92 in the scrap metal chamber 88 is opened by a hoist 94, thus permitting the charge of scrap metal and pig iron 52 to gravitate down the scrap metal stack 58, and into the scrap metal furnace 50.

Alternative embodiments It will be understood by those skilled in the art that alternatively that if, for example, it is essential to expedite the melting of the scrap met-al 52 into molten scrap metal 54, oxygen lance means, such as an oxygen lance 96 (FIGURE 1) operable by a drum 98 may be lowered into the scrap metal furnace 50 to add oxygen to the melting scrap metal 54.

Further additional heat may be provided in the scrap metal furnace 50 by means of `burner means, such as burners 100 (FIGURES 1 and 2).

Alternatively, a fluid control assembly 101 (FIGURES 1, 4 and 5) is used with the basic oxygen furnace 10. If, for example, the basic oxygen furnace 10' is not operating, the swivel hood 28 is rotated from the exhaust gas receiving position (the solid line position of FIGURE 1) to the fluid inlet control position (the dotted line position of FIG-URE 1) by drive ymeans (such as a `girth gear 102 on the swivel hood 28 and a pinon gear 104 on the drive shaft of a motor 106). During such movement the swivel Ihood 28 slides on and is supported by an arcuate rail 108 (FIG-URE 1). In the dotted line position shown in FIG- URE l, the swivel hood 28 engages a sealing member, such as an annular sealing plate 110 (FIGURES 4 and 5), mounted on guides 112. These guides 112 are reciprocable in frame means, such as I-I-beams 114 pistons 116 of fluid operated cylinders 118 (FIGURE 4).

As shown in FIGURE 4, mounting means, such as an open-ended annular frame 120, is mounted on ring 110. This frame 120 conta'ms a fluid preheating means, blower means and iluid inlet control means. The fluid preheating means is by way of example a resistance type air heater 122 connected to a suitable voltage supply or a fluid-tired heat exchanger (not shown). The blower means is a fan 124 mounted on a shaft 126 of a motor 128. Disposed about the shaft 126 is a fixed louver 130 and a movable louver 132 of the `fluid control assembly 101. The movable louver 132 is operable by hand or by a piston 134 of an adjustable fluid operated cylinder 136 to the desired position with respect to the fixed louver 132, thereby controlling the amount of a fluid, such as air, flowing into the swivel hood 28.

Thereafter, the scrap metal 52 (FIGURE 1) within the scarp metal furnace 50 is melted by either the burners 100 or the burners 100 and the oxygen from the oxygen lance 96.

In FIGURE 6, the basic oxygen furnace 106 has a tiltable rotatable vessel 138 and a rotating mechanism 140 driven by a motor 142. The motor 142 drives pinion gears 144 of the rotating mechanism 140 which pinion gears 144 engage girth gears 146 on the vessel 138.

It will be understood that a rotor type basic oxygen furnace (not shown) havin-g a kiln-like vessel may be employed. rI`-he`kiln1ike vessel of the rotor type basic oxygen furnace is rotatable by a rotating mechanism mounted on a base plate and tiltable by a semiciroular tilting gear.

Referring now to FIGURES 7 and 8, the scrap metal furnace 50i7 isv provided with a molten scrap metal portion 507a and scrap metal melting portion 50%, which portions 507e and 50'7b are heated by basic oxygen furnaces 107a, llllb. 'I'he bottom of molten scrap metal portion 507a is sloped toward tap holes 70711, 70'1b and the scrap metal metling portion 5017b is provided with a trough 148 in the bottom to carry molten scrap metal 547 into molten scrap metal portion 507a, Alternatively, the basic oxygen furnaces 10M, 107b can also be connected to the iixed hoods yt6-"a, 46'7b respectively to provide greater flexibility. Also, both basic oxygen furnaces 107a, 107b can be connected by a Y-connection (not shown) to the fixed fhood `46'Ta and the entrance aperture 48"'b blocked off (not shown).

It will be understood by those skilled in the art from the above description of the preferred and alternative embodiments of the present invention, that an improved method is provided.

Method This method comprises the steps of introducing a molten metal producing material, such as the scrap metal 52, into a molten metal prod-ucing furnace, such as the scrap metal furnace S0, conducting the exhaust gases from the basic oxygen furnace 10 (FIGURES 1-4), 106 (FIGURE 6), 107a, 10v7b (FIGURES 7 and 8) to the scrap metal furnace 50, etc. respectively, heating the molten metal producing material, such as the scrap metal v52, by means of the exhaust gases to melt the scrap metal 52 into molten scrap metal 54.

It will be recognized by those skilled in the art that the objects of the present invention have been achieved by providin'g an improved molten metal producing furnace and an improved method for producing molten metal which eliminates the need for a blast furnace and/or cupola for a basic oxygen furnace. Further, such improved apparatus and method substantially utilizes and substantially eliminates the dissipation of the large quantity of heat generated in the conventional ybasic oxygen furnace. Further, the improved apparatus and method substantially partially eliminates the water-cooled hood and related cooling apparatus normally associated with a basic oxygen furnace and substantially reduces the operating costs of such basic oxygen furnace.

While in accordance with the patent statutes, preferred and alternative embodiments have been illustrated and described in detail, it is to be particularly understood that the invention is not limited thereto or thereby.

I claim:

1. In combination:

(a) a basic oxygen furnace provided with exhaust outlet means for exhaust gases from said basic oxy- `gen furnace,

(b) a molten metal producing furnace disposed adjacent said basic oxygen furnace and adapted to receive a molten metal producing material,

(c) conduit means connecting said exhaust outlet means and said molten metal producing furnace so that said exhaust gases engage said molten metal producing material in said molten metal producing furnace in heat exchange engagement to melt said molten metal producing material into molten metal, and

(d) fluid control means adjacent said basic oxygen furnace,

(e) said conduit means having a swivel portion adjacent said exhaust outlet means and drive means connected to said swivel portion for moving said swivel portion between an exhaust gas receiving position adjacent said exhaust outlet means and a fluid inlet control position, adjacent said fluid control means where said swivel portion engages said fluid control means in sealing engagement.

(f) said fluid control means being operable to preheat a fluid and drive said preheated -iiuid through said conduit means and into said molten metal producing furnace when said swivel portion is in sealing engagement with said huid control means.

2. The combination recited in claim 1 wherein said fluid control means has a sealing member engageable with said swivel portion and operating means connected to said sealing member for forcing said sealing memlberinto sealing engagement with said swivel portion.

3. The combination recited in claim 1 wherein said uid control means has fluid inlet control means for controlling the flow of said -fluid througih said conduit means.

4. The combination recited in claim 1 wherein said fluid control means has preheating means for preheating said uid.

5. The combination recited in claim 1 wherein said iiuid control means has blower means for driving said fluid through said conduit means and into said molten metal producing furnace.

6. The combination recited in claim 1 wherein said molten metal producing furnace is provided with exhaust means for said exhaust `gases and has control means in said exhaust means for controlling the flow of said exhaust gases from said molten metal producing furnace through said exhaust means.

7. The combination recited in claim 1 and having supply means disposed between said :basic oxygen furnace and said molten metal producing furnace for transferring molten metal from said molten metal producing furnace to said basic oxygen furnace.

8. The combination recited in claim 1 and having feed means connected tosaid molten metal producing furnace for introducing said molten metal producing material into said molten metal producing furnace.

9. The combination recited in claim 1 wherein said molten metal producing furnace has burner means for assisting the melting of said molten metal producing material.

10. The combination recited in claim 1 wherein said molten metal producing furnace has oxygen lance means for assisting the melting of said molten metal producing material.

11. The combination recited in claim 1 wherein said molten metal producing furnace thas a metal melting portion and a molten metal portion in communication with said metal melting portion.

12. The combination recited in claim 11 wherein said conduit means is connected to said molten metal .portion and having a second basic oxygen furnace provided with a second exhaust outlet means for exhaust gases from said second basic oxygen furnace and having a second conduit means connecting said second exhaust outlet means to said metal melting portion.

13. The combination recited in claim 11 wherein said conduit means is connected to said molten metal portion and having a second basic oxygen furnace provided with a second exhaust outlet means for exhaust gases from said second basic oxygen furnace and having a second conduit means connecting said second exhaust outlet means to said conduit means.

(References on following page) References Cited UNITED STATES PATENTS FOREIGN PATENTS 902,122 7/1962 Great Britain.

Kllling 75760 HYLAND BIZOT, Primary Examiner. clau 266j 3 5 H. W. TARRING, Assismm Examiner. Gorlich et al. 75--43 X AZbe 266 36 US. Cl. X.R. Hall 75--43 X 266-15, 33, 35; 75-43, 60

Bartu 75-60 X 10 Bartu et al. 266-33 X