US1534187A - Hot-metal car - Google Patents

Description

April 21, 1925.

J. D. PUGH HOT METAL CAR Filed May 26, 1921 ATTORNEY 4' Sheets-Sheet 2 I A TTORNEY;

WITNESSES J. D. PUGH HOT METAL CAR April 21, 1925. 1,534,187-

Filed May 26 1921 4 Sheets-Sheet 5 WITNESSES INVENTOR Arm/M918 ,April 21; 1925.

4 Sheets-Sheet 4 Tiz l-le Q 2; o o I g if .1 9 Jr INVENTOR WITNESSES Egg g Patented Apr. 21', 1925.

JOHN D. wen, or mourn wAsHmeroN, BALTIMORE, MARYLAND.

nor-METAL CAR.

' Application filed May 26,

- and State of Maryland, have invented cer:

tain new and useful Improvements in Hot Metal Cars, of which the following is a. specification.

This invention relates to hot metal cars, and more particularly to cars adapted to serve both as mixers and conveyors of mol-- ten metaL On account of the wide variation in-the composition of blast furnace iron,'the usual foundry practice is to cast the same in pigs and then remelt the pigs with other irons ofknown composition to make the .desired foundry mix. I cluding the time required, the additional handling involved, the plant equipment made necessary and the fuel consumed, amounts to a considerable portion of the value of the finished product.

The object of this invention is to secure molten iron from the blast furnace, and to treat the same, while still molten, by the addition of suitable ingredients and by further heating, thereby to obtain a foundryiron of correct composition and fluidity to make sound castings without remelting; and further, to avoid unnecessary pouring, by utilizing the container in which the metal is treated as a conveyor; to store the metal therein without danger of solidifying; and when pouring, to hold back the slag and other impurities floating on the surface of the molten metal. Another object is to produce a'type of conveyor and mixer in which such operations as desulphurizing, decarbonizing, desiliconizing, etc., may be carried on at suitable locations and in which the refined product may be conveyed directly to anypoint in the plant desired.

The introduction of additional heat to the molten metal is rendered necessary by the conduction and radiation losses while storing, and especially to facilitate the processes of treating. The addition of large quantities of modifying elements, such as scrap, ore, etc., tends to chill the mixture and form kish or graphitic carbon, preventing the production of sound uniform castings. Certain refining operations require to be conducted at exceptionally high temperatures.

The heat supply is obtained from an elec- The cost of remelting, in-' 1921. Serial No. 472, s77.

trio current, which, as a source ofheat for such purposes, is superior to the burning of oil or powdered coal, or to other means, by reason of the far more accurate control which it afifords in oxidizing and reducing actions, and by permitting the proper maintenance of the temperatures necessary to metallur ical reactions, and also by facilitating the efinite localization of the heat applied. The primary heating means employed comprises the electric are, which may be of the l'le'roult type of the repelling type, or of any other suitable form. 'A secondary source of heat comprising an electrical resistance heater may be employed where it is desired to heat the under portion of the molten metal, causing convection currents which facilitate mixin To prevent slag, kish am? other impurities from being drawn intothe foundry ladle along with the refined metal, I have devised a novel form of pouring spout and a water cooled skimming bafile associated therewith. The charge may be introduced throu h the electrode openings,-- in which case t e pourin spouts will be used only for .pourin an draining out refuse, and may be ma e smaller than in ordinary cars.

With these and other objects in view, I have devised the apparatus embodying my invention described in the following specification, and illustrated in the accompanying drawings, of whichigure 1 is a side elevation of the car,'.

Figure 2 is an end elevation showing the car in pouring position, g

Figure 3 1s a transverse section of the car taken on the line 33 of Figure 1,

Figure 4 is a transverse section of the car taken on the line of 4-4 of Figure 1,

Figure 5 is a detail plan view of the pourin spout cover and slag skimmer.

igure 6 is a detail elevation of the pouring spout cover and slag skimmer showing water cooling means,

' Figure 7 is a plan view of an electrodetures 15 for the insertion of the electrodes,

and through which the latter may be raised and lowered. Figure 4 shows the application of Heroult type of arc with three phase alternating current. Electrodes 16 are each independently movable, and are each carried in a holder 17, which is bracketed to a telescoping column 18 and raised and lowered by a motor 19 or by other suitable means, so that electrodes 16 may be adjusted to proper position and fed downward as,

. they are consumed. Three bus bars 20 supply current to the respective electrodes. Hollow insulating plugs 21 are secured to the refractory lining 22 of cover 12, and fit loosely around the respective electrodes 16 where the latter enter the cover. Cooling jackets 23, each connected to a supply and to a return pipe, 24 and 25 respectively, provide for the circulation around the respective electrodes, of water or other cooling fluid. Covers 12 are provided with eye bolts 26 to facilitate handling.

When the repelling arc 1s employed, 21

shown in Figures 7 and 8, electrodes 28 connected to bus bars 30, are secured ina holder 29, suitabl' insulated from one another and raised an lowered as a unit for adjusting and feeding the electrodes 28 as the latter are consumed. Holder 29 is packed with refractory material and is carried in a hoop 32 formed of tubing and clamped together at 33, a suspension cable 34 supporting the holder together with the electrodes, and constituting the means for raismg and lowering. Cooling fluid is circulated through tubing 32, the free ends of the latter being secured to atelescoping column similar to 18, or to a suitable guide, and connected to a supply and to a return hose 57 and 58 respectively, for cooling water. A cover 35 fits over opening 7 and is secured to car body 1 in the same manneras cover 12, cover 35 having refractory lining on the interior and a single large opening 36 to fit loosely around holder 29 and permit the latter to be raised and lowered. Cover 35, like cover 12 ,l1as eye bolts 26, and lugs 14 for bolts 13.

When it is desired to apply heat to the lower portion of the molten metal to cause convection currents, bottom electrode plates 37 are employed. These plates 37 are preferably of copper, of large area, and are embedded in the refractory lining of lower portion of the car. The car .body 1 consists of an outer metal shell 38 and an inner lining, which consists of silica or similar material 39 above the level of the molten metal, and of magnesite or similar material 40 elsewhere, the latter then becoming one of the electrodes in the circuit, except that silica or sand 41 is packed between plates 37 and shell 38 as aninsulator. Plate, 37 being in direct contact with magnesite lining 40, the latter permits the passage of current through itself and the bath of-molten metalto an opposite electrode, the bath receiving large quantities of heat caused by the resistance of the magnesite, as well as of the metal itself, to the electric current. A connection 42, insulated from shell 38 and supplied by a cable or bus bar 43, connects plate 37 with the outside source of current.

Pouring spouts 8 are normally closed by covers or caps 44 having a refractory lining 45, and which are secured to car body 1 by bolts '13 fitting in lugs 14, in the same manner as covers 12. Covers 44 are provided with refractory lining 45, and are notched as at 46 on the outeror pouring side so as to leave an' opening through pouring spout 8 for the withdrawal of metal. Depending from cover 44, and following the outline of notch 46 is a refractory slag-skimming baflie 47, which, when cover 44 is secured in position over opening 8, fits against the refractory lining 39 and 40 of the car body 1 to provide within spout 8 a pouring passage of smaller cross sectional area. Baflle 47 is clamped to cover 44 by means of a tube 48, the lower end of which is closed by a flange 49 of greater diameter than that of tube 48, while the upper end extends through cover 44 and is threaded into a nut 50. Flange 49 is embedded or countersunk into the material of the bafile 47 and is protected by means of a plug of fire clay 56 inserted into the portion of the baffle thus countersunk. A fitting 51 is coupled to nut 50 by means of a union 52 and within tube 48 and extending nearly to the bottom thereof is a pipe 53 threaded into and supported by fitting 51, through which pipe 53 extends, the outer end of the latter being coupled to a supply pipe 54 for cooling water. Into the side wall of fitting 51 is threaded a discharge pipe 55.

In conjunction with pouring spout 8 is provided a further means of withdrawing molten metal in the form of a side pouring nozzle 60 having a tap hole 61. This is preferably located in the wall of the pouring spout 8, just above where the latter merges into car body 1, and when the car is tilted for pouring, tap hole 61 opens into the interior thereof at a point well below the level of the molten metal. therein, so that continued through the interior of pouring nozzle 60, and the tap hole 61 is normally closed by a plug 62 of sand, bagging or wood 62, which is only withdrawn after the car is tilted for pouring.

In operation, the car is drawn along a trackway 59 to the blast furnace, or other source of crude molten metal, and the charge is run in through one of the electrode openin s 7,, cover 12 first having been 'removed. T e car is then' drawn further along trackway 59, and the modifying elements, such as various ores, scrap, etc., are added. At convenient stations along trackway 59 are electrode holders with electrodes, together with columns 18, electric conduits, a supply of cooling water, etc. Covers 12 are now clamped over openings 7, the electrodes are introduced and heat applied, and upon completion of the treatment the car is moved along trackway 59 to whatever point the refined metal may be required, the car then being tilted uponits trunnions and the metal withdrawn through openings 8 or 61. When it is desired to store the metal for any length of time, or when the car is to be used simply as a conveyor, electrode covers similar to 12 but without electrode apertures 15 areemployed. Metal may thus be maintained, in molten condition up to thirty-six hours and more. For much longer periods, the car should from time to time be brought to one of the electrode stations for the application of additional heat.

With regard to current, it may be observed that any form of alternating current may be employed. With three phase, all three of the arc'electrodes are connected to the circuit, or any'two of the arc electrodes and the bottom plate if it is desired to heat the lower portion of the metal. IVith single phase current, any two of the arc electrodes may be connected, or any one of the arc electrodes and the bottom plate. Two phase current may also be used and with other phases the proper combinations will be apparent, and where necessary the number of electrodes may be increased. Direct current may be used, but because of its electrolytic efiect is undesirable except in operations'upon non-ferrous materials.

In the number and arrangement of the electrodes, this invention is not to be considered as limited to the previously described forms. Two clusters of arc electrodes, and two bottom plate electrodes are suitable for the size and type of car shown. The larger cars may require more than two clusters, and more than two bottom plates, while in small cars a single arc would be sufficient. In certain cases a plurality of single electrodes, disposed at various points along the length of the car, may be used tion.

Pouring spouts 8 may be made relatively small, as the car. will ordinarily be charged through electrode openings 7. Covers 14 are not removed for pouring, but only for cleaning out refuse. Battle 47 together with the linin of spout 8 constitutes an outlet passage t rou h notch 46 and opening beneath the surIace of the molten metal, so that when car body 1 is tilted for pouring the slag will be held back. This passage may, if desired, be closed with sand, bagging or a wooden plug to prevent loss of heat, but ordinarily this will not be found necessary.

In the use of pouring spout 8 and tap hole 61, the latter will prove more suitable for withdrawing the molten metal in cars of the multiple trunnion type as here shown,

correct composition and fluidity to. make sound. foundry castings. By prolonging and somewhat modifying the treatment required for refining cast iron, cars of this type may-also be used for the direct production of steel.

The invention may also be employed in the treatment and transportation of the nonterrous metals.

As shown in Fig. 1 this invention is illustrated as being embodied in a closed type of hot metal car. With the tap hole shown in Fig. 3, a considerable degree of tilting is necessary and with the trunnion mounting of Fig. 1 the underframe 6 may interfere, so for the object of more completely emptying the car the plurality of trunnions shown in Fig. 2 may be desirable for the purpose of elevating the car to clear the underframe in emptying. The pouring spout 8 is substantially within the lateral limits of the central portion of the car b y- I What I claim is:

1. A large capacity car for treating, transporting, storing and discharging hot metal comprising an elongated car body having an enlarged rounded central portion with conical end portions, mounted on trunnions adjacent its longitudinal axis, a spout on said central portion above the axis thereof, andmeans extending through the upper heating the contents thereof.

efiectively to insure better heat distribu 85 While in certain forms of center trunnion 2. A large capacity car for treating, transporting, storing and discharging hot metal comprising an elongated car body having an enlarged rounded central portion with conical end portions, mounted on trunnions adjacent its longitudinal axis, a spout on said central portion above the axis thereof, said car body being provided with a tap hole in the central portion below said spout, anupwardly extending projection around said hole, and removable electrodes extending through the upper portion of said car body for leading in and out electric current for heating the contents thereof.

3. A large capacity car for treating, transporting, storing and discharging hot metal comprising an elongated car body having an enlarged rounded central portion with conical end portions, mounted on trunnions adjacent its longitudinal axis, a spout on said central portion above the axis thereof, said car body being provided with spaced filling openings on each side of said spout, and electrode heating means movably secured in each opening.

4:. A large capacity car for treating, transporting, storing and discharging hot metal comprising an elongated car body having an enlarged rounded central portion with conical end portions, mounted on trunnions adjacent its longitudinal axis, a spout on said central portion above the .axis thereof, and means for leading in and out an electric current for heating the contents of said car body, said means including a refractory lining for the lower portion of said car body which does not unite with molten iron when used as an electrode. a

5. A large capacity car for treating, transporting, storing and discharging hot metal comprising an elongated car body having an enlarged rounded central portion with conical end portions, mounted on trunnions adjacent its longitudinal axis, a spout on said central portion above the axis thereof, said car body being providedwith a tap hole on the central portion below said spout, an upwardly extending projection surrounding said hole, additional trunnions offset from the longitudinal axis of said car body and arranged to support the same'during the latter part of the pouring movement to 1ncrease the clearance for said car body and tap hole projection, and removable means for electrically heating the contents of said car body.

6. A large capacity car for treating, transporting, storing and discharging hot metal comprising an elongated car body having an enlarged rounded central portion with conical end portions, mounted on trunnions adjacent its longitudinal axis, a spout on said central portion above the axis thereof, a cover extending over the greater portion of said pouring spout and provided with a slag skimming means depending therefrom, and removable means for electrically heating the contents of said car body.

7. A large capacity car for treating, transporting and discharging hot metal comprismg a car body mounted on trunnions for tilting, a pouring spout on the central portion of said car body, the upper portion of said car body being enclosed, and means for electrically heating the contents of said car body, said means including a copper plate embedded in a refractory lining for the lower portion of said car body, which lining does not unite with molten iron when used as an electrode;

8. A large capacity car for treating, transporting, storing and discharging hot metal comprising an elongated car body having an enlarged rounded central portion with conical end portions, mounted on trunnions adjacent its longitudinal axis, a spout on said central portion above the axis thereof, said car body being provided with a filling opening in the upper portion thereof, a cover for thefilling opening, an underframe and trucks on which the car body trunnions are supported, a track for said trucks, and means at the side of said track for removing said cover and inserting and feeding electrodes into said car body to heat the contents thereof.

9. A large capacity car for treating, transporting, storing and discharging hot metal comprising an elongated car body having an enlarged rounded central rtion with conical end portions, mounte on trunnions adjacent its longitudinal axis, a spout on saidcentral portion above the axis thereof, said car body being provided with a filling opening on each side of said pouring spout, and a tap hole below said spout, an upwardly extending projection surrounding said tap hole, inspection means on each side of said tap hole projection and below the filling openings, and means mounted to one side of said our body for supplying electrical energy to heat the contents of the car body.

10. A large capacity car for treating, transporting, storing and discharging hot metal comprising an elongated car body having an enlarged rounded central portion with conical end portions, mounted on trunnions adjacent its longitudinal axis, a spout on said central portion above the axis thereof, and substantially within the lateral limits of said central portion, a cover for the greater portion of said spout, water cooled slag clamping means depending from JOHN D. PUGH.

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