US3439912A - Frame for injectors in melting furnaces - Google Patents

Description

April 22, 1969 BERGER FRAME FOR INJECTORS IN MELTING FURNACES Sheet 012 Filed Sept. 20, 1966 5 M mm L F0 'fl I: i R x 7 l1 4 a m WW I M 5 6 RM Z 0 I m w INVENTORZ NORBERT BERGER BY W4 April 22, 1969 N. BERGER FRAME FOR INJECTORS IN MELTING FURNACES Filed Sept. 20. 1966 Sheet AIIYS.

United States Patent 3,439,912 FRAME FOR INJECTORS IN MELTING FURNACES Norbert Berger, Thalwil, Switzerland, assignor to Maerz Ofenbau, A.G., Zurich, Switzerland, a company of Switzerland Filed Sept. 20, 1966, Ser. No. 580,700 Claims priority, application Austria, Oct. 4, 1965, A 8,966/65 Int. Cl. F27d 7/02; C21c /30 US. Cl. 266-34 9 Claims ABSTRACT OF THE DISCLOSURE A frame for mounting a plurality of injectors such as burners, oxygen lances, etc., for selective projection into the mounting furnace. These injectors are mounted in parallel relation on the frame and the frame is translated to register the selected injector with the furnace opening. Tilting mechanism is provided to incline the selected injector to an angle between 0 and 90 to the horizontal so that the angle may be adjusted. An automatic controller is provided to interconnect the mechanisms which translate the frame, tilt the injector, project the injector, and control the operation of the injectors respectively.

This invention relates to a carrying frame for burners and/or lances for use in the operation of melting furnaces.

In melting furnaces fired with liquid or gaseous fuels, the fuel is supplied in :most cases by water-cooled oil or gas burners or similar heat injectors. Such furnaces may also be used for carrying out exothermic reactions. In this case, there is no need to heat the furnace with fuels supplied from the outside as long as the heat generated by the exothermic reaction is available. Such anoperation may be carried out, e.g., in the open-hearth furnace, in which the solid charge is initially transformed into a molten state with oil or gas flames and the bath is then refined with the aid of oxygen supplied by lances or similar gas injectors. If a sufficiently large amount of oxygen per ton of steel and per hour is supplied during the refining operation, the quantity of heat which is generated in the furnace is sufficient to eliminate the need for firing the furnace with oil or gas. In such furnace, only one type of injector is in operation, i.e., only the burner or only the oxygen lance is in operation. The burners and oxygen lances which protrude into the furnace must be water-cooled and for this reason consume heat. In view of this fact and of the inevitable soiling, it is desirable to leave in the furnace only those burners or lances which are in operation at any one time, and to retract from the furnace all burners or lances which are not in operation. It is further desirable to minimize the number of lead-in openings formed in the furnace for the injectors (burners or lances) because such lead-in openings generally must also be water-cooled, and furthermore permit heat transfer to the exterior, whereby the thermal efiiciency of the furnace is reduced. For this reason, a single lead-in opening should be sufficient, if possible.

In steelmaking processes using large quantities of liquid pig iron, the oxygen lance is in operation for most of the time. For heating up or for an additional increase of the temperature of the charge, the operation of a burner has to be possible at any time. These requirements apply particularly to a twin furnace for processing large amounts of scrap. Also in melting furnaces in which a change from lance to burner or vice versa is not required, it will be of advantage, irrespective whether the blowing lances supply a gas or dust, to provide stand-by lances, which 3,439,912 Patented Apr. 22, 1969 can be inserted into the furnace through the same opening in the brickwork of the furnace as the lances used during normal operation.

It is an object of the invention to provide an apparatus whereby a plurality of injectors (burners and/or lances) can be held in readiness and which enables even during rapidly changing operating conditions a simple and rapid movement of a selected injector into its operative position and a movement of the injector into the furnace, preferably through the same opening in the brickwork, for operation in the furnace.

These objects are accomplished according to the invention by the provision of a carrying frame for injectors (burners and/or lances) for use in the operation of a melting furnace, which carrying frame is characterized in that it comprises a plurality of mountings for a plurality of injectors, which mountings are slidable in an axial direction on or in guides, which are parallel to each other and mounted on the carrying frame. The frame is adjustable to a plurality of predetermined positions, and each of the injectors is aligned when the frame is in a selected one of said positions with the same lead-in opening in the furnace wall.

The guides may be mounted on this carrying frame in such a manner that the axes of the injectors (burners and/or lances) lie on generatrices of a cylindrical surface. In this case, the carrying frame is mounted for rotation about an axis which coincides with the axis of the cylindrical surface, and the carrying frame may be rotatable about this axis without limits or through a limited angle, depending on the number of injectors which are carried by the frame. By such rotation of the carrying frame, each injector can be aligned with the lead-in opening in the furnace and moved into the furnace.

In another embodiment of the invention, the guides for the injectors (burners and/ or lances) are arranged on the carrying frame in such a manner that the axes of all injectors carried by the carrying frame lie in a common plane. To enable an alignment of each injector with the lead-in opening of the furnace, the carrying frame in this embodiment is displaceable transversely to the shifting direction of the injectors along a straight line which is parallel to the plane which extends through the axes of all injectors. In this case, the axes of the injectors may lie in an inclined plane and the carrying frame may he slidable in a horizontal direction, e.g., on horizontal guide rails. When the axes of the injectors lie one over the other in a vertical plane, the carrying frame is raised and lowered, e.g., by a hydraulic jack, for aligning the individual injectors with the lead-in opening of the furnace. Finally, the axes of the injectors may lie in a plane which is at an oblique angle in a direction that is transverse to their direction of movement.

During melting operation it is important that the injectors (burners and/or lances) have a certain angle of inclination relative to the melt. This inclination depends on various factors, such as the furnace structure and the mode of operation. The invention proposes two special embodiments of the carrying frame which enable optimum results to be achieved in the case of changing requirements. In one embodiment, the carrying frame is pivotally movable relative to the horizontal through any desired angle from 0 to about a horizontal tilting axis which is transverse to the axes of the injectors, in all positions to which the carrying frame can be pivotally or slidably moved. In the second embodiment, each of the guides for the mountings of the injectors is pivotally movable relative to the horizontal through any desired angle between 0 and 90 about a horizontal pivot, which is carried by the carrying frame and extends transversely to the axis of the injectors. In this way, the injectors can be moved into the position from which they may be extended into the furnace.

To enable an individual movement of each injector (burner or lance) into and out of the furnace, each of the guides for the mountings of the injectors may have a separate drive, or a common drive may be provided for all guides and be selectively coupled to the guide mounting which has been moved into the working plane.

During melting operation, a frequent change in the character of the injectors, i.e., from burners to lances or vice versa, is required. For this reason, all burners and lances must be supported on the carrying frame in readiness for operation. For this purpose, it is suitable to maintain all injectors (burners and/or lances) constantly in communication with their supply conduits for fuel, oxygen, and cooling Water and to provide these conduits with valves, which are automatically opened when the associated injector is moved forwardly. In such an arrangement, it is sufiicient to change only the position of the injector for a change from burner to lance or vice versa.

The invention will be explained more fully hereinafter with reference to some embodiments shown by way of example in the drawings, in which:

FIGS. 1 and 2 are, respectively, a front elevation and an axial longitudinal sectional view showing a carrying frame in accordance with the invention, which is pivot-ally movable about an axis of rotation;

FIG. 3 shows another carrying frame in accordance with the invention having injector guides which lie horizontally one beside the other;

FIGS. 4 and 5 are respectively, a front elevation and an axial longitudinal sectional view showing another carrying frame in accordance with the invention having injector guides disposed in an inclined plane;

FIG. 6 shows still another carrying frame in accordance with the invention having injector guides which lie vertically one above the other;

FIG. 7 shows yet another carrying frame in accordance with the invention which is rotatable about an axis and has injector guides spaced around the entire periphery of the frame; and

FIG. 8 is a block diagram showing preferred controls for the frame of the present invention.

The carrying frame shown in FIGS. 1 and 2 has three guides 1, which extend parallel to each other and are disposed on generatrices of a surface of a segment of a cylinder and contain mountings 2 for injectors 3 (either burners or lances). Close to their ends, the guides are mounted on posts 4, which are pivotally movable about an axis 6 by means of a drive 5, which may be a hydraulic drive. In this way, any one injector 3 can be moved into the working plane, e.g., the vertical center plane, in which the guide is aligned with the lead-in opening for the injector in the furnace.

To enable a tilting movement of the injector 3 into its working position, the structure which carries the pivot 6 of the carrying frame may be tilted about a transverse axis 9 by means of a drive mechanism 8.

The mountings 2 for the injectors 3 are provided with rollers 10, which are movable in the guides 1. For a movement of an injector into or out of the furnace, these mountings can be axially displaced by a motor 12, tag, with the aid of chains 11. The injectors 3 are connected respectively to a source of cooling water, fuel, oxygen and/or other fluid media by conduits 14 having control valves 15 therein which are controlled by valve operators 16. The injectors are not necessarily the same length and the same diameter. For example, as shown at 3a, the injector is of smaller diameter, and the mounting 2a is modified to accommodate this injector. In like manner, the motor for axially displacing the injector 3a may be operated differently to accommodate a different length.

In the embodiment shown in FIG. 3, the frame comprises three guides 31, each supporting a mounting 32 for a suitable injector 33 by rollers 40. In this embodiment, all guides 31 are mounted on a common plate 37, which can be inclined about a tilting axis (not shown) corresponding to the transverse axis 9 in FIG. 1 or 2. This arrangement enables a tilting of the burners or lances into their operative position. The frame may be moved by drive wheels 35 to selectively position each injector in registry with the lead-in opening in the furnace.

FIG. 4 shows a different arrangement in a frame wherein guides 41 support mountings 42 for injectors 43, as set forth above. In this embodiment, it is not desirable to tilt all guides 41 by means of a common carrying plate, so each guide 41 is mounted on a separate plate 47, which is connected by a hinge 49 to the forward supporting wall 50 of the carrying frame so that each guide can be individually tilted to any desired extent by raising the rear end of the associated plate, for example by a common lifting gear 48 in registry with the lead-in opening and engageable, upon extension, with the plate 47. The frame is displaced by drive wheels 45 when the tilting mechanism is retracted to register the selected injector 43 with the lead-in opening of the furnace, and the tilting mechanism.

In the embodiment of the carrying frame shown in FIG. 6, guides 51 are disposed one over the other to dispose injectors 53 in a vertical plane. The guides are mounted in a framework 57 which can be adjusted by lifting and lowering as indicated by the arrow 55 so as to align any selected injector 53 with the lead-in opening of the furnace.

In the embodiment of FIG. 7, guides '61 are on the generatrices of a cylindrical surface, evenly spaced about the entire periphery of a cylindrical framework 67 which is rotatable about its axis 66 as indicated by the arrow 65 to dispose any selected injector 63 in registry with the lead-in opening of the furnace.

The invention is not restricted to the embodiments shown, which may be modified in their structural details in various respects. Pneumatic, hydraulic or electric drive means may be provided for rotating or displacing and tilting the carrying frame or the individual guides for the mountings of the injectors and for axially moving the injectors into and out of the furnace. As indicated in FIG. 8, the various drives are preferably interconnected by a controller, the drive means for displacing the carrying frame being operable only when the injectors have been retracted from the lead-in opening of the furnace; the motor for displacing the selected injector axially being operable only when the axis of the injector has been properly aligned by the frame drive and tilted by the tilting drive; and the tilting mechanism being operable only when the injector is retracted from the furnace. In this embodiment, each guide has associated with it a displacing motor or other drive means for displacing the injectors axially into and out of the furnace, the motors being interlocked whereby only the one displacing drive means is operable which is associated with the guide of the selected injector which is aligned with the lead-in opening of the furnace and also is operable only when the injector has been tilted to the proper inclination. On the other hand, all guides may have associated with them a common displacing drive motor for displacing the injectors axially into and out of the furnace, only the one mounting of the selected injector being adapted to be coupled to said displacing drive motor or other drive means which preferably is disposed above and aligned with the lead-in opening of the furnace, whereas the mountings of all other injectors are locked against displacement on stops which are non-movable relative to the displacing motor means. In addition, when the motor means for the injector is energized, the valves in the fluid supply conduits for the advancing injector are operated to supply cooling water, fuel, oxygen, and/or other fluid media to the injector. When the injector is retracted from the lead in opening, the controller operates the valves to interrupt the flow through the fiuid supply conduits. Furthermore, each guide for the mountings of the injectors may have associated with it a separate lifting gear for tilting the guides relative to the carrying frame, preferably operable only when its associated guide is in registry with the lead-in opening and its injector is Withdrawn from the furnace.

I claim:

1. A carrying frame for injectors for use in a specified inclined working position at an angle of between 0 and 90 to the horizontal in association with a melting furnace, all of said injectors have permanently connected supply conduits and means for separately controlling the same, comprising a plurality of guides, a mounting for an injector in each guide, said mounting being displaceable in said guides axially of said injectors, said guides being disposed parallel to each other on the carrying frame, means to drive said frame to a plurality of predetermined positions, in each of which an injector is aligned with said working position, means mounting said aligned injector for pivotal movement to said inclined working position, and tilting drive means to vary said angular position.

2. A carrying frame according to claim 1, characterized in that the axes of the injectors lie on generatrices of a cylindrical surface, and the carrying frame is mounted for rotation about the axis of this cylindrical surface to enable any selected one of the injectors to be aligned with said working position.

3. A carrying frame according to claim 1, characterized in that the axes of all injectors lie in a plane, and the carrying frame is displaceable along a straight line which is transverse to the direction of the axial displacement of the injectors and parallel to said plane to enable a movement of any selected one injector into a position in which it is aligned with said working position.

4. A carrying frame according to claim 1 wherein said injector mounting means is operable to pivotally move said frame through any desired angle from O to 90 relative to the horizontal about a horizontal tilting axis transverse to the axes of the injectors at any of said predetermined positions, so that the injectors can be tilted into the proper working position for axial displacement.

5. A carrying frame according to claim 1 wherein said injector mounting means is operable to pivotally move the guide of the aligned injector independently of said frame through any desired angle between 0 to 90 relative to the horizontal about a horizontal tilting axis, transverse to the axis of the injector so that the injector can be tilted into the proper working position for axial displacement.

6. A carrying frame according to claim 1 characterized in that said mountings are different to accommodate injectors which have different lengths and/or different diameters.

7. A' carrying frame according to claim 1, characterized in that the supply conduit control means comprise valves-and a controller connecting said valves and said frame *drive means to open a valve automatically upon advance of the associated injector axially in said working position.

8. A carrying frame according to claim 1 including motor means for axially displacing the injectors, and control; means interconnecting said frame drive means, said tilting .drive means and said motor means for operating said drive means for said frame only when the injectors have been retracted from the furnace, and operating said drive means for axially displacing the aligned injector only when the axis of a selected injector is in said specified inclined working position.

9. A carrying frame according to claim 8, wherein each guide has associated with it a motor means for axially displacing the associated injector, said control means being connected to all of said motor means and adapted to or erate only the one motor means associated with the selected injector which is in said specified inclined Working position.

, References Cited UNITED STATES PATENTS 1,541,621 6/1925 Carini 239 1s7 3,170,977 2/1965 Obenchain 239 1s7 3,358,982. 12/1967 Penn 266-34.2

" FOREIGN PATENTS 866,176 4/1961 Great Britain.

616,647 2/1961 Italy.

CARLTON R. CROYLE, Primary Examiner.

A. D. HERRMANN, Assistant Examiner.

US. Cl. X.R.

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