US3785784A

US3785784A - Scrap blocks for electric furnaces

Info

Publication number: US3785784A
Application number: US00601034A
Authority: US
Inventors: K Tezuka
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-09-03
Filing date: 1966-12-12
Publication date: 1974-01-15
Anticipated expiration: 1991-01-15
Also published as: SE303304B; FI46977B; SE311796B; ES335677A1; DK117366B; NL6702482A; CH463961A; CH462864A; BE692719A; FR1510224A; DE1508092B1; DK111194B; DE1577271A1; DE1577271C3; DE1577271B2; AT275284B; NO119207B; GB1122607A; FI46977C; LU52835A1

Abstract

A metal scrap block for use in electric furnaces is of substantially cylindrical configuration and provided in its outer circumferential surface with angularly spaced longitudinal grooves which extend radially inwardly by between about 1/8 and 1/4 of the block diameter.

Description

United States Patent [1 1 Tezuka 1 Jan. 15, 1974 1 4] SCRAP BLOCKS FOR ELECTRIC 146,092 12/1873 Parmelee 75/44 FURNACES 316,209

[76] Inventor: Kunitoshi Tezuka, 34 7-ch0me,

Minamisuna-machi, Koto-ku, Tokyo, Japan [22] Filed: Dec. 12, 1966 [21] Appl. No.2 601,034

[30] Foreign Application Priority Data Sept. 3, 1966 Japan 41/57944 Sept. 10, 1966 Japan 41/59632 Sept. 30, 1966 Japan 41/64315 [52] us. C1. .[29/186, 75/43, 75/44 s [51] Int. Cl. B21c 37/00 [58] Field of Search '29/186; 100/240; 75/43, 44

[56] References Cited UNITED STATES PATENTS 140,383 7/1873 Pevey .1 75/44 4/1885 Westerman 75/44 FOREIGN PATENTS OR APPLICATIONS 404,608 10/1924 Germany 75/44 Primary Examiner-L. Dewayne Rutledge Assistant Examiner-J. M. Davis [57] I ABSTRACT A metal scrap block for use in electric furnaces is of substantially cylindrical Configuration and provided in its outer Circumferential surface with angularly spaced longitudinal grooves which extend radially inwardly by between about /8 and A1 of the block diameter.

11 Claims, 7 Drawing Figures PATENTEUJAH 15 m4 SHEU 1 0F 2 |NVENTOR KUN/TOSH/ TEZUKA PATENTEDJAMSIQM 3785.784

SHEET 2 0F 2 I "1 g FB. 11L

INVENTOIQ KUN/TOSH/ TEZUKA SCRAP BLOCKS FOR ELECTRIC FURNACES The present invention relates to improvements in scrap blocks of iron and the like to be melted in an electric furnace.

A conventional press machine for shaping metal scrap blocks is composed principally of a hollow, cylindrical press casing and pressing means, and scrap blocks shaped up thereby are solid and cylindrical. An ordinary electric furnace, generally in use, is provided with a hollow and cylindrical furnace and a plurality of electrodes to be inserted into said furnace, so that melting of scraps may be carried out by bringing said electrodes into contact with the upper ends of said charged blocks. Therefore, in the melting of said blocks with electric furnace, the central, axial portion of said blocks is relatively easily melted but the outer peripheral portion thereof tends to remain unmelted in a hollow, cylindrical form. Accordingly, in order to make the melting complete, complicated, troublesome processes have been heretofore in practice: said unmelted portion is cut into several pieces by gas cutters or the like; said pieces are dropped down into the molten metal on the furnace bottom; and then the melting is again carried out. Since the cutting work is performed near the high-temperature furnace it is very dangerous for the workers; also, it is a waste of labor to do the cutting and, moreover, it consumes a great deal of oxygen. Otherwise, in the conventional furnaces, there is a thought to the effect that it should be desirable to provide more electrodes to use also in the positions corresponding to said unmelted portions. However, it is not only difficult in respect to the construction and also undesirable for the safety of the furnace walls to provide more electrode rods near the inner wall of the furnace,; in addition, it is extremely uneconomical of power consumption to increase the number of electrode rods.

The object of this invention is to provide a method of making metal scrap blocks which can be completely melted in electric furnaces efficiently as well as economically and without requiring cutting work such as mentioned above.

Metal scrap blocks according to this invention are solid and substantially cylindrical, having parallel slots formed on the outer periphery thereof in the direction of the ge neratrixes. Said blocks will be completely melted, in the melting'process by electric furnace, efficiently and economically on account of the provision of these slots.

The number, depth, cross-sectional shape, etc. of

said slots will be suitably designed to make effective the delivery, melting, etc. of blocks; it is particularly desir able to determine the depth of slots at about A to Va of the diameter of said blocks and said cross-sectional shape as trapezoidal, square, triangular, semicircular or in any other form.

Other objects and advantages of the present invention will become apparent from the further following description taken in connection with the appended drawings in which:

FIG. 1 is an oblique view of a metal scrap block;

FIG. 2 is a frontal view of a press machine showing a vertically-sectional view of its casing and pressing means;

FIG. 3 is a-plane view of the casing;

FIG. 4 is a bottom view of the pressing means;

FIG. 5 is a partial plane view of another embodiment of the casing;

FIG. 6 is a partial plane view of another embodiment of the casing; and

FIG. 7 is a schematic figure for illustrating the melt ing in an electric furnace.

ln reference to the drawings, scrap block 1 as shown in PK]. 1 is solid and substantially cylindrical, made with iron scraps pressed and thus shaped, its outer pe' riphery having four slots 2 whose cross-sectional shape is trapezoidal, formed at equal intervals and in parallel to each other in the direction of the generatrixes and extending from the one end 3 to the other end 4; the depth in the diametrical direction of said slots 2 is about 1/5 of the diameter of said block I.

Said block 1 is completely melted in electric furnace efficiently as well as economically as the following description will clarify. In FIG. 7, said block 1 is inserted into an electric furnace P with its end 3 facing upward; electrode rods E are inserted into the furnace from above and the lower rod ends are brought down upon the upper end 3 of said block 1. Utilizing the requisite electric current, the melting is started. The central,

axial portion of said block first begins to melt and the molten metal thereof gathers in the furnace bottom, said axial portion lying in the direction of extension of said electrode rods. Said melting further develops gradually and outwardly to reach said slots 2 eventually, whereupon the outer peripheral portion of the block which has hitherto tended to remain unmelted in a hollow and cylindrical shape, separates into into four pieces C along said slots 2, each of said pieces C then slipping down by its own weight into the molten metal on the bottom where it is naturally all melted.

' x araz agaisrta ras1;;a this iiiventi o ii will naturally and completely melt in the electric furnace having no portion left unmelted at all and therefore said blocks will enable the melting process to be carried out markedly more efficiently in comparison to conventional blocks, and will also enable a considerable reduction in the electric power consumption of the electric furnace.

Th s as rhaiiii Efiihbfifisiofsi bisaid"blacks is within the range of about A to Vs of the diameter of block will affect said melting and other processes very favorably, because, if said depth is too small, it will make difficult the separation into pieces of the unmelted portion of said blocks, thus obstructing the efficient, economical and complete melting of the blocks; if said depth is too great, on the other hand, it will make the blocks too easily breakable, thus decreasing the operational efficiency inldelivery and transfer of blocks.

Now a press machine for shaping said metal scrap blocks will be described in the following:

The press machine is composedmainly of a press casing and pressing means. Referring to FIGS. 2 and 3, the press casing 5 whose one end is entirely open is steelmade and substantially cylindrical, having its inner surface 6 welded with four ridged steel male dies 7 at equal intervals in parallel to each other in the direction of the generatrixes from the casing opening 8 to the bottom 9. The number, diametrical height of ridges, cross-sectional shape, etc. of said male dies 7 should be suitably determined with a view to making effective the pressing, removal of blocks out of the casing, melting, etc. Saidridge height, in particular, is about 1/5 of the and a large gear 19 secured to the top of said press disk.

inner diameter of the casing in the foregoing example but it is preferable to select the effective range of about V: to V8 of the inner diameter of the casing. The crosssectional shape thereof is trapezoidal in the above example but any other form such as square, triangular, semicircular shapes may be adopted.

Further, a description will be made concerning the pressing means and the attached devices thereof. As the pressing members of the present device, those which are conventionally known to the public or other variety which can be thought of in the future may be as well freely utilized with this invention, but the examples herein shown have adopted pressing members which comprise a number of spot press rams moved by a fluid pressure cylinder such as oil-pressure or hydraulic cyll inder and a rotary press disk having a concavo-convex part on its pressing face.

Iieferring to FIGS. 2, 4 and 5 two oil-pressure cylinders 12 for elevating the rotary press disk 11 are borne vertically by a beam of a gate-type frame F and the lower ends of the rams 13 of said cylinders are secured to a supporting block 14. The convex part 15 of said press disk 11 is shaped in a cross, the shaft 16 standing on said press disk being rotatably and suspendedly borne with bearing. A motor 17 for rotating said press disk is mounted to said supporting block 14, and the rotation of the motor is transmitted to the press disk 11 by way of a pinion 18 of the drive shaft of the motor Four oil-pressure cylinders 21 for lowering all the spot press rams to the pressing position are borne also by said beam 10. The lower ends of those rams 22 are secured to an annular supporting member 23, on which a number of oil-pressure cylinders 24 for the spot rams are supported vertically. The spot ram 20 of each cylinder 24 penetrates, as is so adapted, the supporting ring slidably so as to be able to move back and forth from the underside of the ring.

protrudingly at equal intervals on its upper face, the upper end of said leg being secured to said ram 22. And said each leg 25 has, on its inside, slots 26 formed as extending from the underside of the ring, said slots being so adapted as to fit into each male die 7 of said casing when pressing is effected. Further, in the relation of said casing with said pressing means, said supporting ring 23 is devised so as to have its outer diameter made just large enough to be insertable into said casing 5, and said press disk 11 is devised so as to have its diameter made also just large enough to be insertable into said casing without touching the male die 7.

On the H66??? there are laid two guide rails 28 extending outwardly from the underside of said press means or the pressing portion, and said casing is slidably mounted onto said floor in'a manner such that two rail grooves 29 provided underside of said casing fit said rails 28.

In the operation, iron scraps are charged into said casing 5 and said casing is moved to its pressing position. Thereafter, by sending a hydraulic fluid into the oil-

pressure cylinders

12, 21, said press disk 11 and supporting ring 23 are lowered into said casing 5, and thereby prepressing is carried out. Subsequently, in the first place, said press disk 11 is elevated back to its original position where the motor 17 is put to work, thus the press disk is rotated slightly, whereafter pressing is carried out repeatedly several times in the same manher. On the other hand, each of said spot press rams 20 is projected out and made recede in repeatedly several times in the same manner by sending a hydraulic fluid into each oil-pressure cylinder 24. By virtue of a series of these pressing processes, each scrap lump is intermingled and compressed into a fully compact condition.

W After pressing is through as aforementioned, said casing 5 is moved outwardly and a block is removed out as shaped up. The resultant block thus obtained is cylindrical as specified, as is shown in FIG. 1, having four slots 2 formed on its outer periphery, and moreover, since each scrap lump has been intermingled and fully compressed, it is easy in delivery or transfer.

Insaid press machine, the fact that the ridge height of said male die is about V1 to b of the inner diameter of said casing is desirable in shaping specified blocks. In other words, if the ridge height is too high, easily breakable blocks will be shaped up disadvantageously, in addition to its becoming an obstacle in the pressing; if the ridge height is too low, it will be impossible to shape blocks which are able to be completely melted efficiently as well as economically.

According to kinds, material properties of metal scraps to be disposed, or construction of the pressing means, or other conditions, there'will occur occasions wherein the aforementioned male dies must be replaced by other dies having ridge height, crosssectional shape, etc., differing from said male dies. To cope with such a necessity as this, a press casing which is removably provided with male dies is furnished herewith. Referring to FIG. 6, there are provided opposedly one each or more projections 30 as supporting means on both sides of the position on the inner wall 6 of the casing wherein a male die is to be set in. If a male die 7a is fitted between said opposing projections with its base, circumferentially shifting thereof will be hampered advantageously by said supporting means; there will be no occurrence of any obstruction in the scrap charging and also in the pressing operation but the same object as the foregoing example will be achieved. In this case, it is preferable to make the inner surface 6 of said casing tapered gently toward the bottom, forming a gentle incline. As such supporting means, further, there can be employed a variety of means such as means for fixing male dies to the casing with screws.

"w'itsaarsiaisu gsng'aezs grsviaea iris possible as well to achieve the same object of this invention, as in the foregoing examples, with a press casing which is composed of said male die 7a just standing against the inner surface 6 casing in a specified position of the as is shown in FIG. 7. In such a casing, it is necessary to have the inner surface 6 of said casing inclined as aforementioned.

In the press casing provided with said removable male dies or standing-type male dies, it is possible to use male dies 7a manufacturing of other material such as wood that is combustible at a temperature lower than the melting point of metal scraps. In this case, when blocks are removed from the casing after shaping them up, it may occur that a block is removed together with the male die 7d which is made of wood and has clung to a block such as mentioned abovejthe male die may either be removed off the block and again used, or

be put into the electric furnace together with the block and be burned up while the block is melted away.

What is claimed is: I

- l. A metal scrap block for use in an electric furnace, said block consisting of at least substantially compacted metal scraps having in cross-section a substantially cylindrical portion and a substantially conical portion converging gradually in a direction towards one axial end of said block, provided with a plurality of circumferentially spaced axial grooves extending from the periphery of said block at least substantially radially inwardly towards but short of a center portion of said block, said center portion being substantially solid,- said grooves having a length approaching that of said block, so that, when said block is melted from the center in radially outward direction, the grooved annular outer portion of the block separates along the respective grooves into segments which collapse radially inwardly.

2 A metal scrap bloclc as defined in claim ll, wherein said grooves are of constant cross-section.

3.'A"iii tal s'cisabraeie'marsezrmiaMiriam said grooves converge in cross-sectional areas in direction radially inwardly of said block.

' 4.A"asar'scia smsak'asazfisamaaira Eli/Herein said block has a predetermined diameter, and wherein said grooves have a depth which corresponds to between substantially and A of said predetermined diameter.

from said periphery inwardly towards the center of said block,

said grooves approaching the length of said block and being dimensioned so that, when said block is disposed in the melting chamber of an electric furnace and melting electrodes are advanced in said chamber axially of said block toward said center portion so as to melt the same and in so doing to enter into and hollow out said block,

the remaining unmelted outer annular portion of the block in which said grooves are provided will separate along the inner boundaries of the respective grooves into individual segments which will collapse under their own weight in radially inward direction so as to come within the melting effectiveness range of said electrodes to be melted by the same.

6. A metal scrap block as defined in claim 5, said grooves having a cross-sectional configuration which converges in direction towards said center of said block.

7. A metal scrap block as defined in claim 5, said grooves having a cross-sectional configuration which is constant in direction towards said center of said block.

8. A metal scrap block as defined in claim 5, wherein said outer annular portion is comparatively narrow.

9. A metal scrap block as defined in claim 5, said block having a predetermined cylindrical diameter; and wherein said grooves have a depth in direction towards said center which corresponds to between substantially /8 and A of. said predetermined diameter.

10. A metal scrap block as defined in claim 5, said block having a predetermined cylindrical diameter; and wherein said grooves have a'depth in direction towards said center which corresponds to about 1/5 of said predetermined diameter. I

11. A metal scrap block as defined in claim 5, wherein said block is adapted to rest on said frustoconical end portion upon being melted in the melting chamber of an electric furnace.

Claims

2. A metal scrap block as defined in claim 1, wherein said grooves are of constant cross-section.
3. A metal scrap block as defined in claim 1, wherein said grooves converge in cross-sectional areas in direction radially inwardly of said block.
4. A metal scrap block as defined in claim 1, wherein said block has a predetermined diameter, and wherein said grooves have a depth which corresponds to between substantially 1/8 and 1/4 of said predetermined diameter.
5. A metal scrap block to be melted in an electric furnace, being composed substantially of a solid center portion and an outer annular portion having in cross-section a substantially cylindrical main portion and a frusto-conical end portion with a diameter converging from said cylindrical portion, said outer portion being provided with a plurality of circumferentially spaced axial grooves extending from said periphery inwardly towards the center of said block, said grooves approaching the length of said block and being dimensioned so that, when said block is disposed in the melting chamber of an electric furnace and melting electrodes are advanced in said chamber axially of said block toward said center portion so as to melt the same and in so doing to enter into and hollow out said block, the remaining unmelted outer annular portion of the block in which said grooves are provided will separate along the inner boundaries of the respective grooves into individual segments which will collapse under their own weight in radially inward direction so as to come within the melting effectiveness range of said electrodes to be melted by the same.
6. A metal scrap block as defined in claim 5, said grooves having a cross-sectional configuration which converges in direction towards said center of said block.
7. A metal scrap block as defined in claim 5, said grooves having a cross-sectional configuration which is constant in direction towards said center of said block.
8. A metal scrap block as defined in claim 5, wherein said outer annular portion is comparatively narrow.
9. A metal scrap block as defined in claim 5, said block having a predetermined cylindrical diameter; and wherein said grooves have a depth in direction towards said center which corresponds to between substantially 1/8 and 1/4 of said predetermined diameter.
10. A metal scrap block as defined in claim 5, said block having a predetermined cylindrical diameter; and wherein said grooves have a depth in direction towards said center which corresponds to about 1/5 of said predetermined diameter.
11. A metal scrap block as defined in claim 5, wherein said block is adapted to rest on said frusto-conical end portion upon being melted in the melting chamber of an electric furnace.