Title:
VERTICAL REMOTE-CONTROLLED REFRACTORY GUNNING APPARATUS
United States Patent 3799445


Abstract:
A vertical gunning conduit having a horizontal nozzle at its lower end is supported from a hoist above and extends into the open top of a refractory-lined vessel, such as an electric steel-making furnace, with the nozzle positioned within the vessel. Refractory materials and water are supplied to the top of the conduit through a mixing head, which is connected by a swivel coupling to the lower portion of the conduit which is rotatable about its axis. An oscillating drive provided by a crank and slotted lever, is connected to the rotatable conduit through a magnetic clutch which is actuable to engage at a variable angle to control the position of the nozzle, either motionless for filling large holes, or in an oscillating path for gunning a selected portion of the vessel wall.



Inventors:
MARINO J
Application Number:
05/355752
Publication Date:
03/26/1974
Filing Date:
04/30/1973
Assignee:
PFIZER INC,US
Primary Class:
Other Classes:
118/317, 239/210, 239/227, 239/255, 239/264
International Classes:
B22D41/02; B05B3/14; B23K9/04; F27B3/12; F27D1/16; (IPC1-7): B05B3/14
Field of Search:
239/225,227,264,210,242,255,187,132.3 118
View Patent Images:



Foreign References:
GB1176978A1970-01-07
Primary Examiner:
King, Lloyd L.
Assistant Examiner:
Kashnikow, Andres
Attorney, Agent or Firm:
Connolly, And Hutz
Claims:
I claim

1. A vertical refractory gunning apparatus comprising a vertical gunning conduit, a control unit, bearing means rotatably connecting and mounting said vertical gunning conduit from said control unit, an oscillating drive in said control unit, a drive coupling in said control unit connecting said oscillating drive to said vertical gunning conduit supply conduits entering said control unit for supplying refractory material and water, a mixing head in said control unit to which said supply conduits are connected, a swivel coupling connecting said mixing head to said vertical gunning conduit for providing a mixture of water and refractory to said nozzle, and actuating means connected to said oscillating drive for selectively actuating it to control the angular orientation of said nozzle whereby said nozzle is angularly oriented about said vertical gunning conduit in stationary and oscillating modes of operation.

2. An apparatus as set forth in claim 1 wherein said drive coupling is a clutch.

3. An apparatus as set forth in claim 2 wherein said oscillating drive includes a crank and slotted lever linkage.

4. An apparatus as set forth in claim 3 wherein said crank comprises a rotating disc and crank pin.

5. An apparatus as set forth in claim 3 wherein said slotted lever is connected to part of said clutch.

6. An apparatus as set forth in claim 2 wherein said clutch is a magnetic clutch, and said actuating means is an electric switching device.

7. An apparatus as set forth in claim 1 wherein said oscillating drive comprises a reversible motor.

8. An apparatus as set forth in claim 7 wherein said reversible motor comprises an air driven motor.

9. An apparatus as set forth in claim 1 wherein said control unit is disposed within a control casing.

10. An apparatus as set forth in claim 1 wherein said actuating means is disposed remotely from said control unit and vertical gunning conduit.

Description:
Background of the Invention

Maintenance of the refractory linings in vertical refractory lined vessels, such as an electric steel-making furnace, is complicated by the necessity to insert the gunning nozzle through the top of the vessel and direct it at the portions of the vessel which require repair of maintenance. Existing gunning apparatus, such as described in U. S. Pat. Nos. 3,351,289, 3,396,855 and 3,473,737, is designed for direct operation within movable steel-making furnaces such as BOFS and is therefore not as efficient for remote operation through the top of a stationary furnace. An object of this invention is to provide a vertically movable refractory gunning apparatus which can be remotely directed and controlled to selectively gun any and all portions of vertical refractory lined vessels.

Summary of the Invention

A vertical gunning conduit having a horizontal nozzle at its lower end is supportable from a hoist above the top and extending within a refractory-lined vessel, such as an electric steel-making furnace. Refractory materials and water are supplied to the top of the conduit through a mixing head, which is connected by a swivel coupling to the lower portion of the conduit which is rotatable about its axis. An oscillating drive is connected to the rotatable conduit, either directly or through a clutch which is actuable to engage at a variable angle, to control the position of the nozzle either motionless for filling large holes or in an oscillating path for gunning a selected portion of the vessel wall. The oscillating drive, which is provided for example by a reversible motor or crank and slotted lever, helps apply an even coating to the vessel walls.

Brief Description of the Drawings

Novel features and advantages of the present invention will become apparent to one skilled in the art from a reading of the following description in conjunction with the accompanying drawings wherein similar reference characters refer to similar parts and in which:

FIG. 1 is a partially schematic view in elevation of one embodiment of this invention being used to spray an open-topped refractory-lined vessel, which is shown in cross-section;

FIG. 2 is a top plan view of the driving and mixing compartment of the embodiment shown in FIG. 1 with cover removed;

FIG. 3 is a cross-sectional view taken through FIG. 2 along the line 3--3;

FIG. 4 is a cross-sectional view taken through FIG. 2 along the line 4--4;

FIG. 5 is a schematic view of the oscillating drive portion of the embodiment of this invention shown in FIGS. 1-4 in one phase of operation;

FIG. 6 is another schematic view of the oscillating drive portion of the embodiment of this invention shown in FIGS. 1-4 in another phase of operation;

FIG. 7 is still another schematic view of the oscillating drive portion of the embodiment of this invention shown in FIGS. 1-4 in a third phase of operation;

FIG. 8 is another schematic view of the oscillating drive portion of the embodiment of this invention shown in FIGS. 1-4 in a fourth phase of operation;

FIG. 9 is another schematic view of the oscillating drive portion of the embodiment of this invention shown in FIGS. 1-4 in a fifth phase of operation;

FIG. 10 is another schematic view of the oscillating drive portion of the embodiment of this invention shown in FIGS. 1-4 in a sixth phase of operation; and

FIG. 11 is a view in elevation of the driving and mixing compartment of another embodiment of this invention.

Description of the Preferred Embodiment

In FIG. 1 is shown a vertical remote controlled refactory gunning apparatus 10 supported fom an overhead trolley hoist 12 above a refractory lined electric steel-making furnace 14 whose top is removed to provide access to the interior. Hoist 12 is bidirectionally movable on trolley wheels 15 along beam 16, which is traversed perpendicularly to its length by wheels 18 riding on tracks 20 secured to the overhead structure; alternatively, apparatus 10 can be supported from a separate jib crane.

Apparatus 10 includes a vertical conduit 22 extending from contol box 24 into the vessel and having a nozzle 26 extending from it at a substantial angle, for example at right angles, toward refractory lined wall 28 of furnace 14. Nozzle 26 is for example of the type shown in U. S. Pat. No. 3,392,921. Nozzle 26 is herein shown directed at a substantially right angle to conduit 22, but this may be varied according to special requirements. Conduit 30 supplies water to control box 24 from hydrant 32. Conduit 34 supplies a dry refractory mixture from supply tank or so-called refractory gun 36, which is manually replenished through its open top. Conduits 30 and 34 are suspended in sling 40 from cab 42 of hoist 12 to clear the upper corners of furnace 14. A spray pattern 44 is directed at wall 28 from nozzle 26 in a manner later described in detail.

Details of control box 24 and its contents are shown in FIGS. 2-4. Vertical conduit 22 extends into the bottom of control box 24 through thrust bearing 46 within which it is rotatable and which supports its weight. Lower clutch plate 48 of magnetic clutch 50 is secured to conduit 22 and the drive portion 52 of clutch 50 supported rotatably mounted upon conduit 22 below swivel coupling 54 which joins rotatable conduit 22 to refractory supply conduit 34 suppoted in sleeve mounting bracket 56. Refractory supply conduit 34 is connected to swivel coupling 54 by water supply Tee 58 having a connecting nipple 60 to which water supply conduit 30 is connected, thus comprising a mixing head.

Electric drive motor 62 having a geared reducing head 64 rotates crank disc 66 in a horizontal plane. Crank pin 68 on disc 66 is inserted in longitudinal slot 70 within lever 72 which is secured for exgmle by welding to collar 73 connected to the drive example 52 of clutch 50. Rotation of crank disc 66 accordingly oscillates drive portion 52 of clutch 50 in a manner later described.

FIGS. 5-10 show various angular phases of lever 72 and nozzle 26 in the operation of the oscillating drive 84 provided by the aforementioned driving components. Magnetic clutch 50 is accordingly actuable to engage at variable angles to control the oscillation of lever 72 and nozzle 26 in order to traverse the oscillating path of nozzle 26 completely around the interior of furnace 14. Clutch 50 is actuated by a manual switch by an operator to disengage the clutch at one extremity of travel of lever 72 and pick it up at the other extremity of travel in order to successively traverse in arcuate path of nozzle 26 around the entire interior of furnace 14.

FIG. 5 shows lever 72 in an illustrative initial disposition relative to nozzle 26 in which they are, for example, in straight line relationship with each other. Nozzle 26 therefore swings in an oscillating path, for example of 45°, which is centered upon the longitudinal centerline of lever 72.

The crank and slotted lever connection of the rotating motion of motor 62 and gear drive 64 to lever 72 provides a sine wave motion. Wall 8 has a diameter of for example approximately 16 to 20 feet whereas, the axis of rotation 90 of nozzle 26 is for example positioned at from two feet from the wall to the center of the vessel.

The relative phases of oscillation of lever 72 and nozzle 26 are shown in sucessive FIGS. 5-10. In FIG. 6 lever 72 and nozzle 26 are in line with each other at the extremity of angle A1. In FIG. 7 the aligned lever and nozzle have returned to the center of angle A2 the same as in FIG. 5. In FIG. 7, however, crank pin 68 is adjacent nozzle 26, whereas in FIG. 5 it is remote from nozzle 26. In FIG. 8 aligned lever 72 and nozzle 26 are at the extremity of angle A3.

The rotation of nozzle 26 with respect to lever 72 is illustrated in FIGS. 9 and 10. In FIG. 9, magnetic clutch 50 is inactivated when lever 72 is at the A3 position shown in solid outline and lever 72 then rotates to the A1 position shown in phantom outline while nozzle 26 remains in the A3 position. Clutch 50 is then reactivated to reengage lever 72 and nozzle 26 in the last mentioned angular orientation which is maintained in FIG. 10.

In FIG. 10, nozzle 26 is being oscillated throughout a new angle B which is rotated 45° from former angle A with nozzle 26 and lever 72 in a 135° disposition relative to each other about axis 90. Clutch 50 is successively deactivated and reactivated while lever 72 is traversed from one extremity of travel to the other to progressively index nozzle 26 in full rotation about its axis. This permits the entire interior wall 28 of furnace 14 to be systematically gunned with refractory material. Magnetic clutch 50 also permits a deep hole in any particular area to be filled by stopping the nozzle and directing it continuously at the hole for a sufficient period of time to fill it. Remote actuation of apparatus 10 is guided by an operator by visual inspection and control either through a viewing port or door 92 in the furnace wall, from a remote elevated platform or possibly from cab 42 of hoist 12.

Apparatus 10 may be used to gun any effective mixture of a dry refractory mixture with water. One effective type of mixture is a high silica content mixture. Others would include high alumina or high magnesia content mixtures. The material may be sprayed while the furnace is hot or cold. The most effective thickness will be dictated by the particular local condition. It will often be between one and four inches for each gunning operation, but it may sometimes range from less than one inch to in excess of 6 inches. The hot gunning operation permitted by this remote controlled unit is highly advantageous because it takes about 6 or 8 hours to cool a furnace sufficiently to gun it with directly operated apparatus. The positional flexibility afforded by this remotely operated unit highly facilitates direction of the coating mixture at any spot or area of the furnace with highly accurate control from a remote station.

Water control valve 57 is interposed in conduit 30 to maintain a substantially constant quantity of water flowing into mixing Tee 58. Valve 57 is of any suitable available type obtainable from various control valve manufacturers. It insures correct proportioning of water and dry refractory composition at mixing Tee 58 and nozzle 26.

FIG. 11 shows a modification 10 A of the embodiment illustrated in FIG. 3, which incorporates a direct drive in place of the clutch drive. Coupling gear 91 A is secured to conduit 22 A in place of the magnetic clutch and is driven by coupling drive gear 93 A attached to air motor 94 A through sprocket chain 92 A. Air motor 94 A is of the reversing type and its rotational direction is controlled by a solenoid valve 95 A and timer 96 A. Timer 96 A determines the period during which the motor 94 A turns in a given direction before reversing. Timer 96 A is set to a predetermined setting, e.g., 5 seconds. Every 5 seconds the Timer 96 A actuates the solenoid to switch the air supply to the opposite port of motor 94 A, causing it to reverse its directon of rotation. The length of arc traversed by the nozzle may thus be varied by varying the timer setting. An electrical override (not shown) over timer 96 A is preferably provided so that nozzle movement can be manually controlled when desired. Air flow to motor 94 A may also be varied to vary the drive speed. Timer 96 A and its override may be positioned remote from control box 24 A to facilitate actuation by an operator.