GB2105642A - Apparatus for sizing a blast furnace runner - Google Patents

Abstract

Apparatus 14 for sizing a refractory-lined blast furnace runner 10 comprises a rotatable milling head 34 mounted on a milling arm 19 which is pivotally mounted on a chassis 15 for movement in a vertical plane. The chassis 15 is mounted on rotary support means such as endless drivable tracks 16. <IMAGE>

Description

SPECIFICATION Apparatus for sizing a blast furnace runner This invention relates to apparatus for sizing a refractory-lined furnace runner or other channel provided with a refractory lining.

Blast furnace runners, or other channels used for conveying molten pig-iron or other metallic melts, are provided with a refractory lining, generally in the form of a tamping clay. This lining has to be renewed at regular intervals of, for example, four to six weeks, since it undergoes considerable wear. The normal practice is to remove the damaged iayers of refractory lining, enriched with pig-iron, using pneumatic drills, and then to restore or re-establish the refractory lining by introducing tamping-clay into a shuttering system. This mode of operation is extremely expensive as regards the work involved, and also suffers from the disadvantage that a considerable proportion of the still usable refractory material of the runner lining is destroyed, this representing a considerable loss of valuable tamping clay.

The aim of the invention is to provide apparatus for sizing a refractory-lined blast furnace runner which does not suffer from these disadvantages.

The present invention provides apparatus for sizing a refractory-lined blast furnace runner, the apparatus comprising a rotatable milling head mounted on a milling arm which is movable in a vertical plane.

With this sizing apparatus, a worn refractory lining can be mechanically removed by the milling head in various thicknesses of, for example, from 5 to 10 cm depending upon the profile resulting from wear; and excessive removal of lining material, accompanied by considerable losses of valuable tamping clay, can be avoided. Moreover, selective milling out of a runner is possible in specific zones, for example in regions affected by erosion. It is also possible to mill grooves in the base of the runner for anchoring the side walls to the base. In addition, this sizing apparatus can be used for totally clearing a blast furnace runner of refractory material. The milling operation on the refractory lining improves the adhesive effect when the fresh refractory composition is applied.

Preferably, the milling arm is pivotally mounted on a chassis for movement in a vertical plane.

In order to enable the sizing apparatus to deal with several blast furnace runners (or other channels provided with a refractory lining), and to permit the apparatus to be moved to the various runners (or channels), or even along the runner that is to be sized, it is expedient to provide the apparatus with its own means of travel.

Advantageously, therefore, the chassis is mounted on rotary support means. The rotary support means may be constituted by a pair of drivable endless tracks or a plurality of drivable wheels. in either case, the rotary support means can only be used for moving the apparatus to the various work areas within one operating region. In order to support and advance the sizing apparatus during the milling of a blast furnace runner or the like, the apparatus may further comprise guide means for supporting the apparatus for movement along a pair of rails which extend in the longitudinal direction of the runner. The rails can be laid at both sides of the runner or at only one side thereof.

Advantageously, the apparatus further comprises lifting means for lifting the chassis and the rotary support means clear of the ground so that, during its operating movement, the sizing apparatus is supported by the guide means on the rails. The distance between the track (or wheels) at the chassis sides is expediently less than the distance between the rails.

In a preferred embodiment, the guide means is constituted by a plurality of guide elements, the guide elements being vertically movable relative to the chassis by the lifting means.

Advantageously, each of the guide elements is a shoe which is slidable along one of the rails, and each of the shoes is mounted on the chassis by means of a respective hydraulic ram, the hydraulic rams constituting the lifting means.

The apparatus may further comprise a support frame which surrounds and supports the chassis of the apparatus. In this case, the guide elements may be mounted on the support frame and be vertically movable relative thereto by the lifting means. The support frame, together with the guide elements, imparts stability to the sizing apparatus during milling operations. Preferably, the support frame is rectangular, being constituted by a pair of parallel longitudinal beams and a pair of parallel transverse beams. In this case, there may be four guide elements, the guide elements being positioned at the corners of the support frame.

Alternatively, each of the guide elements is pivotally mounted on the chassis by means of a vertically pivotable rocker arm, the chassis is generally rectangular, and there are four guide elements positioned at the corners of the chassis.

In this case, each of the rocker arms may be vertically pivotable by means of a respective hydraulic ram acting between that rocker arm and the chassis. Preferably, each of the rocker arms is vertically pivotable through at least 900, and the guide elements are guide wheels. Advantageously, the guide wheels at one side of the chassis are double-flanged wheels, and the guide wheels at the other side of the chassis are flange-less wheels.

Preferably, the apparatus further comprises means for moving the sizing apparatus along the rails. Said means may be constituted by hydraulic ram means. Where the chassis is supported by a rectangular support frame, the hydraulic ram means may be constituted by a pair of hydraulic rams, and each hydraulic ram is pivotally attached between a respective one of the longitudinal beams and a detachable rail-gripping device. The rail-gripping devices are arranged to grip the rails during extension of the rams so that this causes the sizing apparatus to be advanced. The devices are then released from the rails and the rams retracted. The devices can then be re-fixed to the rails ready for another advance movement.

Alternatively, the sizing apparatus may further comprise drive means for driving the endless tracks, said drive means also constituting the means for moving the sizing apparatus along the rails. Preferably, said drive means drives the endless tracks via a drive shaft, and the drive shaft is provided with a winch at at least one end thereof, the or each winch being cooperable with elongate traction means for driving the sizing apparatus along the rails. The or each traction means may be constituted by a cable (or chain), one end of which is fixed to the associated winch and the other end of which is fixed to a stationary member fixed to the ground, the or each cable being wound onto, or off, the associated winch when the winch is driven, thereby moving the sizing apparatus along the rails.

Advantageously, the milling arm is pivotally mounted on the chassis for lateral movement.

Moreover, that part of the milling arm that carries the milling head may be rotatable about its own longitudinal axis. Preferably, the milling head is rotatably mounted on the milling arm by means of a shaft which extends at right-angles to the longitudinal axis of the milling arm, and the milling head is constituted by two milling discs.

Alternatively, the milling head is constituted by a milling roller which is disposed at the free end of the milling arm at one side thereof, and that portion of the milling arm which carries the milling roller is rotatable through 1 800. the milling roller can, therefore, be pivoted so that it can be used for milling the side walls of the runner as well as the base thereof. The position of the milling roller can also be adapted to deal with the particular form and location of any eroded or cavitated areas of the refractory lining.

Since, in some circumstances, the refractory lining of the blast furnace runner may be at a high temperature of, for example, 500 to 7000C during milling operations, it is preferred to provide a drive motorforthe milling head on the milling arm in such a way that it lies outside the runner, and cannot become heated to an undesirable extent during use. In this case, the milling head is driven by the drive motor by way of a chain drive arranged on the milling arm.

In order to permit the sides walls of the runner to be milled, the chassis may be transversely displaceable relative to the support frame. Where the support frame is rectangular, the chassis may be transversely displaceable by means of a pair of hydraulic rams housed within the transverse beams.

The milling arm may be vertically pivotable through at least 1 800 relative to the chassis. In this case, the chassis may be of arch-like construction, and the milling arm is pivotable underneath the arch-like chassis from one end thereof to the other. This enables milling operations to be carried out to the front and rear of the chassis, and so permits the entire length of a runner to be milled without having to turn the entire apparatus round through 1800.

The milling arm may be constituted by a cranked jib. the cranked jib having a first jib part which carries the milling head, and a second jib part which is connected to the first jib part and is pivotally mounted on the chassis about a pivot joint. The two jib parts may be rigidly or pivotally connected together. The cranked form of jib enables the milling arm to swing down steeply, so that the milling head can operate immediately adjacent to the end of the chassis.

Advantageously, the milling arm is vertically pivotable by means of at least one hydraulic ram mounted between the milling arm and the chassis.

Preferably, the or each hydraulic ram is positioned above the pivot joint which connects the second jib part to the chassis. This enables the height of the sizing apparatus to be relatively small.

Conveniently, the milling arm is mounted on a rotary support which is rotatably mounted on the chassis.

In a preferred embodiment, the milling arm is a jib constituted by a plurality of detachably connected jib parts. Advantageously, the jib is a cranked jib having first, second and third parts, the first jib part carrying the milling head, the second jib part being pivotally mounted on the chassis, and the third jib part being a wedge-shaped member which is detachable connected to the first and second jib parts. Preferably, the third jib part has opposite end faces which are inclined to one another at an acute angle. In this case, the drive motor for the milling head may be carried by the first jib part. Thus, the milling head, the first jib part and the drive motor form a single constructional unit which can be connected to other types of apparatus such as dredgers.This multi-part construction of the milling arm enables the length of the arm, and the crank angle, to be changed to suit particular operating conditions, it being possible to use wedge-shaped members of differing dimensions and crank angle.

Preferably, the rotary support means is constituted by two pairs of wheels, each pair of wheels being engageable with a respective rail which extends in the longitudinal direction of the runner, and one wheel of each pair is directly drivable by a respective drive motor mounted on the chassis, and the other wheel of that pair is driven by said one wheel via an endless drive chain.

The rotary support may be a double turntable constituted by a lower turntable and an upper turntable, the upper turntable carrying the milling arm, and the lower turntable being mounted on the chassis. In this case the apparatus may further comprise a locking bolt for detachably locking the two turntables together for preventing relative rotation therebetween. Advantageously, the turntables are such that the locking bolt can be used for detachably locking the turntables together in any one of a plurality of predetermined relative positions.

Advantageously, the apparatus further comprises a separate loading device mounted by a jib on the chassis. The loading device may be a scoop and is used to lift the milled-away material from the runner.

The sizing apparatus of the invention is mainly intended for use in repair work on blast furnace runners, although it can also be used for sizing the refractory lining from other equipment, for example, conveying containers, tilting chutes and the like. The apparatus of the invention may also be provided with means for building on a tamping device whereby the refractory tamping composition can be applied during reconstruction operations.

Several forms of blast furnace runner sizing apparatus, each of which is constructed in accordance with the invention, will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a side elevation of a first form of sizing apparatus; Fig. 2 is a plan view of the apparatus of Fig. 1; Fig. 3 is a rear elevation of the apparatus of Figs. 1 and 2: Figs. 4 and 5 show, in side elevation and plan view respectively, a modified form of milling arm for use in the apparatus of Figs. 1 to 3; Fig. 6 is a side elevation of a second form of sizing apparatus; Fig. 7 is a cross-section taken on the line VIl-VIl of Fig. 6; Figs. 8 and 9 show, in side elevation and plan view respectively; third and fourth forms of sizing apparatus; Fig. 10 is an end elevation of a fifth form of sizing apparatus; Fig. 11 is a side elevation of a sixth form of sizing apparatus; and, Fig. 12 is a plan view of the sizing apparatus of Fig. 11.

Referring to the drawings, Fig. 1 shows a blast furnace runner 10 through which molten pig-iron and slag flow from a blast furnace (now shown) to conveyor vessels such as ladles. The runner 10 typically has a length of 1 5 to 25 metres, and is provided with a tamped refractory lining 11 (see Fig. 3). During operation of the furnace, the refractory lining 11 wears, and must, therefore, be renewed, at least partially, at certain intervals. In Fig. 3, the original cross-sectional shape of the runner 10 is shown in dash-dot lines 12, whereas the contour of the worn refractory lining 11 is indicated by the reference numeral 1 3. Before the worn lining 11 is renewed, it must be sized, that is to say its profile must be restored to one having a uniform cross-section.This requires the worn lining to be removed by a thickness of between 5 and 10 cm depending upon the amount of wear that has occurred. The lining 11 is then restored to the required profile 12, by introducing a tamped refractory material into a shuttering system.

In order to size the worn refractory lining 11, use is made of a sizing apparatus 1 4 (see Figs. 1 to 3), which has a chassis 15 supported by a pair of drivable endless tracks 1 6. The chassis 1 5 carries a rotary support 1 7 having a vertical axis of rotation. The rotary support 1 7 carries a mounting 18, and a milling arm 19 is pivotally attached to the mounting by a pivot joint 20 having a horizontal pivotal axis. The milling arm 1 9 can, therefore, be pivoted laterally as well as vertically with respect to the chassis 1 5 of the sizing apparatus 14. Lateral pivoting is achieved by means of hydraulic rams 21, which are articulated between the chassis 1 5 and the rotary support 1 7.

Vertical pivoting of the milling arm 1 9 is achieved by means of hydraulic rams 22, which are articulated between the mounting 1 8 and the milling arm 19.

A drive unit 23 is provided at the rear of the chassis 1 5. The chassis 1 5 also carries a seat 24 for the operator.

The entire sizing apparatus 14 (including the chassis 1 5 and the tracks 16) is mounted on a rectangular frame 25. The frame 25 is constituted by two parallel, longitudinal beams 26 and two parallel, transverse beams 27. The frame 25 surrounds the chassis 1 5 and the tracks 1 6.

Hydraulic lifting devices 28 are arranged at the four corners of the frame 25, the hydraulic lifting devices each comprising a hydraulic lifting ram 29 and a U-shaped slide shoe 30. The slide shoes 30 are slidably supported on a pair of parallel rails 31, the two rails being laid on the ground at opposite sides of the runner 10. The rails 31 are each positioned a pre-determined distance from the adjacent side of the runner 1 0, and they extend over at least the entire length of the runner.

The milling arm 1 9 is a cranked jib, having an upper jib part 32 and a tapering lower jib part 33 rigidly attached to the upper jib part at an angle thereto. The upper jib part 32 is mounted in the pivot joint 20, and the lower jib part 33 carries a milling head 34 at its free end. The milling head 34 is connected to the free end of the lower jib part 33 by means of a pivot pin 35 which extends at right-angies to the longitudinal axis of the lower jib part. The milling head 34 is constituted by two narrow milling discs 36 (see Fig. 2), which are arranged one on either side of the tapered jib part 33, and which rotate about the pivot pin 35. A hydraulic motor 37 is provided for driving the two milling discs 36, the motor being arranged at the upper end of the jib part 33. The hydraulic drive motor 37 may be a slow-turning motor, or a rapidly-turning motor having a reduction gear. The motor 37 drives the milling head 34 by way of an endless drive chain 38, which is accommodated within the jib part 33.

The chassis 15, together with the tracks 1 6 and the milling arm 19, is mounted on the rectangular frame 25, and is transverly displaceable relative thereto. This transverse displacement takes place on guide rails 39 which embrace the transverse beams 27. Hydraulic rams 40 are provided for effecting this transverse displacement, the rams 40 being articulated between the guide rails 39 and the transverse beams 27. The hydraulic rams 40 lie within (and so are protected by) the transverse beams 27. Thus, with the aid of the rams 40, the entire sizing apparatus 14 can be displaced transversely relatively to the frame 25, so that the working position of the milling head 34 can be adjusted in the lateral direction.

During milling operations, the sizing apparatus 14 is supported on the rails 31 by its frame 25 and the lifting devices 28, the lifting rams 29 being extended so as to lift the tracks 1 6 away from the ground. The vertical and lateral pivotal movements of the milling arm 19, and the transverse displaceability of the entire apparatus 14 using the rams 40, enable the milling head 34 to be accurately aligned with the two side walls and the base of the refractory lining 11 of the runner 10.

Thus, the refractory lining 11 can be sized, by the rotating milling head 34, in an appropriate manner corresponding to the profile resulting from wear.

During the milling work, the entire sizing apparatus 14, together with its frame 25, is moved along the rails 31 by means of a feed device 41. The feed device 41 is constituted by a pair of hydraulic rams 42. Each of the rams 42 is pivotally connected to one of the longitudinal beams 26 by a pivot joint 43, and to a respective rail-gripping device 45 by a pivot joint 44. The gripping devices 45 slide along the rails 31, which they embrace from above in the manner of tongs.

The gripping devices 45 can be releasably secured to the rails 31, so that, during movement of the sizing apparatus 14 along the rails 31 , they constitute an abutment for the rams 42. As soon as a working stroke of the rams 42 is completed, the gripping devices 45 are disengaged from the rails 31. The rams 42 are then retracted so that the gripping devices 45 slide along the rails 31.

The gripping devices 45 are then locked to the rails 31 again, so that further extension of the rams 42 causes the entire sizing apparatus 14 to advance through a distance equal to the working stroke of the rams 42.

A loading device 46 is provided for loading the material cut away by the milling arm 1 9. The loading device 46 is constituted by a loading or dredging scoop 47 which is pivotally mounted on a jib 48. The jib 48 is mounted on the rotary support 17 by means of pivot joints 49 and 50.

The pivot joint 49 permits the jib 48 to pivot in a vertical plane, and the pivot joint 50 permits the jib 48 to pivot in a horizontal plane. Hydraulic rams are provided for effecting the pivotal movements in these two planes, as well as for pivoting the scoop 47 relative to the jib 48.

Since the sizing apparatus 14 is supported on the two rails 31, it is stable during milling operations, so that very accurate milling cuts can be carried out. As soon as the sizing of the runner 10 has been completed, the sizing apparatus 14 is lowered, by retracting the hydraulic lifting devices 28, until the tracks 16 engage the ground. The sizing apparatus 14 can then be moved on its tracks 1 6 to a new operating site, or to its storage place. The milling work generally begins at the end of the runner 10 adjacent to the blast furnace; and during milling, the sizing apparatus 14 is moved backwards.

The sizing apparatus 14 can also be used to remove an entire refractory lining 11. For this purpose, the scoop 47 is replaced by a hammer (not shown) which is used to break up the refractory lining. It is also possible to connect a tamping device to the jib 48, so as to consolidate the fresh tamping material introduced for renewing the refractory lining.

Figs. 4 and 5 illustrate a modified form of milling arm 19. Here, the milling arm 19 has a jib part 19' which is rotatable about its longitudinal axis, as indicated by the arrow 1 5. A milling roller 52 is mounted at one side of the free lower end of the jib part 19', the milling roller 52 being rotatable about an axis extending transversely of the axis of the jib part 1 9'. Fig. 5 shows the milling roller 52 in a working position, in which it cuts into one of the two side walls of the refractory lining 11. In order to cut into the other side wall of the refractory lining 11 , the jib part 19', together with the milling roller 52, is turned through 1800 in the direction indicated by the arrow 51. When the jib part 19' is turned through 1 800, the direction of rotation of the milling roller 52 changes.In order to carry out a cutting operation that does not destroy the bond of the refractory lining with the milling roller 52 on either the left-hand side or the right-hand side of the jib part 19', it is recommended that, when the milling roller is changed from the left-hand side to the right-hand side, the direction of movement of the entire sizing apparatus 14 is reversed. For example, if the milling roller 52 is on the left-hand side of the jib part 19' when the apparatus is moved forwards, the apparatus is moved backwards when the milling roller is on the right-hand side of the jib part 1 9'.

Figs. 6 and 7 show diagrammatically a second form of sizing apparatus 14. This sizing apparatus 14 is similar to the apparatus shown in Figs. 1 to 3, and so corresponding parts have been given the same reference numerals. In Figs. 6 and 7, the sizing apparatus 14 is provided with four rocker arms 60 instead of the frame 25. The rocker arms 60 are mounted for vertical pivotal movement on pivot joints 61 at the four corners of the chassis 1 5. In this embodiment, the lifting devices 28 are hydraulic rams 62 pivotally fitted between the chassis 1 5 and the rocker arms 60. The arrangement is such that the rocker arms 60 can be pivoted upwardly from the position shown in Fig. 7 (in which they support the entire sizing apparatus 14 on the rails 31), through at least 900, in the direction indicated by the arrow 63, into the position 60', indicated in dash-dot lines in Fig. 7, in which the sizing apparatus 14 can be moved on its tracks 1 6. When the rocker arms are in the positions 60' they lie substantially within the lateral limits of the sizing apparatus 14 and so do not substantially increase the width of the apparatus.

Each of the rocker arms 60 is provided with wheels 64 and 65 at the opposite ends thereof.

Each rocker arm 60 has a pair of wheels 64 or 65, the wheels 64 being positioned at one side of the chassis 15, and the wheels 65 being positioned at the other side of the chassis. Each pair of wheels is pivotally mounted on its rocker arm 60 by means of a rocker unit 66. Each rocker unit 66 is pivotally mounted on its rocker arm 60 by a pivot pin 67, the axis of which is parallel to, and positioned midway between, the axles of the wheels 64 or 65 of that rocker unit. The wheels 64 at one side of the sizing apparatus 14, that is to say the wheels shown on the left in Fig. 7, are formed with twin flanges 68 which engage opposite sides of the associated rail 31, and so provide lateral guidance.

The wheels 65 at the other side of the sizing apparatus 14, that is to say the wheels on the right-hand side of the apparatus, are rollers having no flanges. This enables the wheels 65 to adapt themselves to variations that may occur in the gauge of the rails 31.

In order to advance the sizing apparatus 14 of Figs. 6 and 7 during sizing operations a feed device similar to the device 41 of the apparatus shown in Figs. 1 to 3 may be used. Preferably, however, the drive for the tracks 1 6 may be used to advance the apparatus 14 along the rails 31. In the arrangement shown in Figs. 6 and 7, this is achieved by mounting a winch 69 on the drive shaft of the tracks 1 6, the winch co-operating with a cable 70. One end of cable 70 is secured to the winch 69, and the other end of the cable is fixed to a stationary member. As the winch 69 rotates, the cable 70 is wound onto (or off) the winch, thus causing the apparatus 14 to move along the rails 31. Obviously, the cable 70 could be replaced by a chain or the like.

The sizing apparatus 14 illustrated in Figs. 6 and 7, like that of Figs. 1 to 3, moves backwards during the sizing (milling) operations. When nearing the end of the runner 10 remote from the blast furnace, the entire apparatus 14 must be lifted from the rails 31 , for example, by means of a crane (not shown). It is then turned through 1 800 and replaced on the rails 31 , so that the refractory lining 11 at this end of the runner 10 can be sized by moving the sizing apparatus 1 4 backwards.To enable the sizing apparatus 14 of Figs. 6 and 7 move along the rails 31 after it has been turned through 180 , without having to provide a cable 70 at both sides, the drive shaft of the tracks 1 6 is provided with a winch 69 at each end (see Fig. 7).

Fig. 8 shows diagrammatically a third form of sizing apparatus 14. This sizing apparatus 14 is movable along the rails 31 when orientated in a position at right-angles to that of the first two forms of apparatus. In this case, the rails 31 are laid at the same side of the runner 10. The sizing apparatus 14 may be supported on the two rails 31 in the same way as that shown in Figs. 6 and 7. in other words, this apparatus 14 may be provided with rocker arms 60, which can be pivoted upwards relatively to the chassis 1 5, and which carry wheels 64 and 65. During the milling work, the apparatus 14 moves along the rails 31, that is to say, in the longitudinal direction of the runner 10, but it is disposed with its longitudinal axis at right-angles to the direction in which the rails 31 extend.

The milling arm 1 9 of this embodiment is constituted by an upper jib part 32 and a lower jib part 33. The upper jib part is pivotally mounted, for movement in a vertical plane, by the pivot joint 20, and the lower jib part 33 carries the milling head 34 and its two milling discs 36. The lower jib part 33 is connected to the upper jib part 32 by a pivot joint 81 , the axis of which extends in the longitudinal direction of the runner 10. Fig. 8 shows the milling discs 36 in a working position, in which they operate on the base of the refractory lining 11 of the runner 10. To enable the sides wall zones of the runner 10 to be machined, the entire milling head 34 can be rotatably mounted, by a rotary element 82, on the lower jib part 33.

The rotary element 82 is rotatable relative to the lower jib part 33 about its longitudinal axis in the direction indicated by the arrow 83, so that the milling discs 36 can be swung round to bring their peripheral faces into contact with the side walls of the runner 10. The milling head 34 is set against that face of the runner 10 that is to be milled, by means of one or more hydraulic rams 84 articulated between the jib parts 32 and 33.

Fig. 9 shows diagrammatically a fourth form of sizing apparatus 14. This apparatus also has a chassis 1 5 provided with tracks 16, the apparatus being movable along on rails 31 laid at both sides of the runner 10. As with the embodiment of Fig.

8, the apparatus 14 is arranged, during milling operations, with its longitudinal axis at rightangles to the longitudinal axis of the runner 10.

Here again, the sizing apparatus 14 is supported on the two rails 31 by rocker arms 60 which are vertically pivotable on the chassis 1 5. The rocker arms 60 are provided with wheels 64 and 65. The milling arm 19, which carries the milling head 34, is supported on the mounting 1 8 so as to be pivotable vertically about the horizontal pivot joint 20.The mounting 18 is supported by the rotary support 17, which can be pivoted about a vertical pivot pin 91, preferably through 3600 and at least through approximately 1 800. In this case, therefore, it is possible to pivot the milling arm 1 9 through roughly 1 800 from a first operating position (in which its milling head 34 is presented to that end of the runner 10 that is adjacent to the blast furnace) into a second operating position (in which the milling head 34 faces the opposite end of the runner 10). The sizing apparatus 14 can, therefore, carry out milling work in both directions of travel, and does not require to be turned through 1 800 as is the case with the forms of apparatus shown in Figs. 1 to 7.

A fifth form of sizing apparatus 14, which can operate in both directions of travel (and so likewise does not need to be turned through 1800 to work the two ends of the runner 10) is shown in Fig. 10. This sizing apparatus 1 4 comprises a chassis 100, which straddles the runner 10, is provided with tracks 16, and which can be advanced along the rails 31 laid at both sides of the runner 10. In order to lift the sizing apparatus 14 and to support it on the rails 31, vertically pivotable rocker arms 60 are again provided, the rocker arms having wheels 64 and 65 as in the apparatus shown in Figs. 6 and 7. The milling arm 1 9 is here suspended to pivot vertically and laterally on an upper web portion 101 of the archlike chassis 100.The arrangement is such that the entire milling arm 1 9 can be pivoted underneath the chassis 100 so as to carry out milling operations at both ends thereof, so that the apparatus 14 is able to operate on the entire length of the runner 1 0, without having to be turned through 1800 on the rails 31. As with the modification shown in Figs. 4 and 5, that part of the milling arm 1 9 that carries the milling head 34 is rotatable about the longitudinal axis of the milling arm.

Figs. 11 and 12 show a sixth form of sizing apparatus 14 having a chassis 1 5 which is movable along the rails 31 laid at the sides of the runner 10 on wheels 110 and 111. The chassis has a pair of wheels 111 which are directly driven.

and a pair of wheels 110 which are driven by the wheels 111. The wheels 110 and 111 at each side of the chassis are, therefore, driven by a common drive motor 112, for example a hydraulic drive motor. The arrangement is such that each of the wheels 111 is driven directly by its drive motor 112, whereas the other wheels 110 are driven by the wheels 111. This driving connection is achieved by means of endless chains 11 3 which pass round sprockets 114 mounted on the axles of the wheels 110 and 111 (see Fig. 12). The chain drives 113 and 114 are mounted in, and protected by, U-shaped housings 11 5, which are connected to bearing parts 11 6 accommodating the wheels 110 and 111. 1 shown in Fig. 12, one of the drive motors 112 is positioned at the front of the chassis 15, whereas the other drive motor 112 is positioned at the rear of the chassis. The driving connection between the pairs of wheels 110 and 111 results in the sizing apparatus 14 having a four-wheel drive, and ensures that at least one driven pair of wheels is in contact with the rails 31 even if the other pair of wheels have been lifted away from the rails under the reaction force of the driven milling head 34.

As with the embodiment of Figs. 1 to 3, the milling arm 19 is in the form of a cranked jib, and is mounted by the horizontal pivot joint 20 on the rotary support 17. The milling arm 1 9 is pivotable vertically by means of two parallel hydraulic rams 22, which here are disposed at a distance above the pivot joint 20.The rotary support 1 7 has an upstanding bracket 1 8. to the upper end of which the rams 22 are connected by means of pivot joints 11 7. The pivot joint 20 lies below the pivot joints 11 7 and immediately above the rotary support 1 7. The low-level pivot joint 20 enables the cranked jib 1 9 to pivot very steeply downwards into the runner 10, as indicated at 19', so that the sizing apparatus 14 is also able to carry out milling operations immediately adjacent to its chassis 1 5. In this way. the radius of action of the milling arm 1 9 is increased.

The cranked jib 1 9 is of multi-part construction.

It is constituted by an upper jib part 32 connected to the pivot joint 20, a wedge-shaped intermediate jib part 118, and a lower jib part 33.

The milling head 34 is mounted on the free end of the lower jib part 33. The wedge-shaped intermediate jib part 118 has end faces 11 9 and 120, which lie at an acute angle to one another, and to which the jib parts 32 and 33 are detachably connected by, for example, bolted flanges. The multi-part construction of the milling arm 19, and the detachability of the jib parts 32, 118 and 33, enable the milling arm to be adjusted to different lengths and crank angles. Thus, intermediate parts 11 8 of differing dimensions, and having their connecting faces 11 9 and 120 at different angles, may be used.

The drive for the milling head 34 is mounted on the lower jib part 33. It consists of two hydraulic drive motors 1-21, which are arranged one on either side of the jib part 33. The two motors 121 drive a common drive wheel 123 via a gear 1 22.

The drive wheel 123 is arranged within the jib part 33 which is of box-girder construction. The drive wheel 123 is a sprocket wheel, and drives the milling head 34 by way of a chain 125. The chain 125 is housed within the jib part 33, is guided by a chain-tensioning device 124, and drives the milling head 34 by passing round a sprocket wheel 126 positioned between the two milling discs of the milling head. The jib part 33, together with the milling head 34 and its drive, forms an enclosed structural unit, which may also be connected to an existing travel mechanism, for example, the travel mechanism of a scoop or a dredger.

The rotary support 1 7 is constituted by two superposed turntables 127 and 128, which are rotatable about a vertical shaft 129 of the rotary support. The lower turntable 127 is rotatable by means of two generally parallel hydraulic rams 21.

The cylinders of the rams 21 are pivoted to the chassis 1 5 by pivot joints 1 30, and their piston rods are pivotally connected, by pivot joints 131, to connection pieces 132 attached to the lower turntable 127. The upper turntable 128 carries the mounting bracket 18, the drive unit 23, the operator's seat 24, and the milling arm 1 9. The two turntables 127 and 128 can be locked together by means of a locking bolt 133 to form a single unit. Consequently, they can be pivoted together through an angle of 200, for example, in either direction about the vertical shaft 129 by the rams 21. After release of the locking bolt 1 33, the upper turntable 128, and all the parts mounted thereon, can be pivoted about the vertical shaft 129 and relatively to the lower turntable 127, so as to bring the milling arm 1 9 into another working position. If the sizing apparatus 14 is to operate in the opposite direction, the milling arm 19, together with its turntable 128, is rotated through 1 800 on to the opposite side of the chassis 1 5. In this position, the turntable is resecured to the lower turntable 127 with the aid of the locking bolt 1 33. It is, however, also possible to bring the milling arm 1 9 into several intermediate positions. As shown in Fig. 12, the turntables 127 and 128 have apertures 134 for receiving bolts, and these apertures are spaced apart by 600, for example, so that the two turntables 127 and 128 can be locked in different relative positions corresponding to these spacings.

The multi-part milling arm 19 described above with reference to Figs. 10 and 11, could also be incorporated in the first five forms of sizing apparatus.

Claims (52)

1. Apparatus for sizing a refractory-lined blast furnace runner, the apparatus comprising a rotatable milling head mounted on a milling arm which is movable in a vertical plane.

2. Sizing apparatus as claimed in claim 1, wherein the milling arm is pivotally mounted on a chassis for movement in a vertical plane.

3. Sizing apparatus as claimed in claim 2, wherein the chassis is mounted on rotary support means.

4. Sizing apparatus as claimed in claim 3, wherein the rotary support means is constituted by a pair of drivable endless tracks.

5. Sizing apparatus as claimed in claim 3, wherein the rotary support means is constituted by a plurality of drivable wheels.

6. Sizing apparatus as claimed in any one of claims 1 to 5, further comprising guide means for supporting the apparatus for movement along a pair of rails which extend in the longitudinal direction of the runner.

7. Sizing apparatus as claimed in any one of claims 3 to 5, or as claimed in claim 6 when appendant to claim 3, further comprising lifting means for lifting the chassis and the rotary support means clear of the ground.

8. Sizing apparatus as claimed in claim 7, wherein the guide means is constituted by a plurality of guide elements, the guide elements being vertically movable relative to the chassis by the lifting means.

9. Sizing apparatus as claimed in claim 8, wherein each of the guide elements is a shoe which is slidable along one of the rails.

10. Sizing apparatus as claimed in claim 9, wherein each of the shoes is mounted on the chassis by means of a respective hydraulic ram, the hydraulic rams constituting the lifting means.

11. Sizing apparatus as claimed in any one of claims 2 to 10, further comprising a support frame which surrounds and supports the chassis of the apparatus.

12. Sizing apparatus as claimed in claim 11 when appendant to claim 8, wherein the guide elements are mounted on the support frame.

13. Sizing apparatus as claimed in claim 12, wherein the guide elements are vertically movable relative to the support frame by the lifting means.

14. Sizing apparatus as claimed in any one of claims 11 to 13, wherein the support frame is rectangular, being constituted by a pair of parallel longitudinal beams and a pair of parallel transverse beams.

1 5. Sizing apparatus as claimed in claim 14 when appendant to claim 12, wherein there are four guide elements, the guide elements being positioned at the corners of the support frame.

1 6. Sizing apparatus as claimed in claim 8, wherein each of the guide elements is pivotally mounted on the chassis by means of a vertically pivotable rocker arm.

17. Sizing apparatus as claimed in claim 16, wherein the chassis is generally rectangular, and there are four guide elements positioned at the corners of the chassis.

1 8. Sizing apparatus as claimed in claim 16 or claim 1 7, wherein each of the rocker arms is vertically pivotable by means of a respective hydraulic ram acting between that rocker arm and the chassis.

19. Sizing apparatus as claimed in claim 18, wherein each of the rocker arms is vertically pivotable through at least 900.

20. Sizing apparatus as claimed in any one of claims 1 6 to 19, wherein the guide elements are guide wheels.

21. Sizing apparatus as claimed in claim 20, wherein the guide wheels at one side of the chassis are double-flanged wheels, and the guide wheels at the other side of the chassis are flangeless wheels.

22. Sizing apparatus as claimed in claim 6, or in any one of claims 7 to 21 when appendant to claim 6, further comprising means for moving the sizing apparatus along the rails.

23. Sizing apparatus as claimed in claim 22, wherein said means is constituted by hydraulic ram means.

24. Sizing apparatus as claimed in claim 23 when appendant to claim 14, wherein the hydraulic ram means is constituted by a pair of hydraulic rams, and wherein each hydraulic ram is pivotally attached between a respective one of the longitudinal beams and a detachable rail-gripping device.

25. Sizing apparatus as claimed in claim 22 when appendant to claim 4, further comprising drive means for driving the endless tracks, said drive means also constituting the means for moving the sizing apparatus along the rails.

26. Sizing apparatus as claimed in claim 25, wherein said drive means drives the endless tracks via a drive shaft, and wherein the drive shaft is provided with a winch at at least one end thereof, the or each winch being cooperable with elongate traction means for driving the sizing apparatus along the rails.

27. Sizing apparatus as claimed in claim 26, wherein the or each traction means is constituted by a cable, one end of which is fixed to the associated winch and the other end of which is fixed to a stationary member fixed to the ground, the or each cable being wound onto, or off, the associated winch when the winch is driven, thereby moving the sizing apparatus along the rails.

28. Sizing apparatus as claimed in claim 2, or in any one of claims 3 to 27 when appendant to claim 2, wherein the milling arm is pivotally mounted on the chassis for lateral movement.

29. Sizing apparatus as claimed in any one of claims 1 to 28, wherein that part of the milling arm that carries the milling head is rotatable about its own longitudinal axis.

30. Sizing apparatus as claimed in any one of claims 1 to 29, wherein the milling head is rotatably mounted on the milling arm by means of a shaft which extends at right-angles to the longitudinal axis of the milling arm.

31. Sizing apparatus as claimed in any one of claims 1 to 30, wherein the milling head is constituted by two milling discs.

32. Sizing apparatus as claimed in claim 2, or in any one of claims 3 to 31 when appendant to claim 2, wherein the milling arm is constituted by a cranked jib, the cranked jib having a first jib part which carries the milling head, and a second jib part which is connected to the first jib part and is pivotally mounted on the chassis about a pivot joint.

33. Sizing apparatus as claimed in claim 32, wherein the two jib parts are rigidly connected together.

34. Sizing apparatus as claimed in claim 32, wherein the two jib parts are pivotally connected together.

35. Sizing apparatus as claimed in any one of claims 1 to 30, wherein the milling head is constituted by a milling roller which is disposed at the free end of the milling arm at one side thereof, and wherein that portion of the milling arm which carries the milling roller is rotatable through 1 800.

36. Sizing apparatus as claimed in claim 2, or in any one of claims 3 to 35 when appendant to claim 2, wherein the milling arm is vertically pivotable through at least 1 800 relative to the chassis.

37. Sizing apparatus as claimed in claim 36, wherein the chassis is of arch-like construction, and the milling arm is pivotable underneath the arch-like chassis from one end thereof to the other.

38. Sizing apparatus as claimed in claim 2, or in any one of claims 3 to 37 when appendant to claim 2, wherein the milling arm is vertically pivotable by means of at least one hydraulic ram mounted between the milling arm and the chassis.

39. Sizing apparatus as claimed in claim 38 when appendant to claim 32, wherein the or each hydraulic ram is positioned above the pivot joint which connects the second jib part to the chassis.

40. Sizing apparatus as claimed in claim 2, or in any one of claims 3 to 39 when appendant to claim 2, wherein the milling arm is mounted on a rotary support which is rotatably mounted on the chassis.

41. Sizing apparatus as claimed in any one of claims 2 to 40, wherein the milling arm is a jib constituted by a plurality of detachably connected jib parts.

42. Sizing apparatus as claimed in claim 41, wherein the jib is a cranked jib having first, second and third parts, the first jib part carrying the milling head, the second jib part being pivotally mounted on the chassis, and the third jib part being a wedge-shaped member which is detachably connected to the first and second jib parts.

43. Sizing apparatus as claimed in claim 42, wherein the third jib part has opposite end faces which are inclined to one another at an acute angle.

44. Sizing apparatus as claimed in claim 32, claim 42 or claim 43, further comprising a drive motor for driving the milling head, the drive motor being carried by the first jib part.

45. Sizing apparatus as claimed in claim 5, or in any one of claims 6 to 44 when appendant to claim 5, wherein the rotary support means is constituted by two pairs of wheels, each pair of wheels being engageable with-a respective rail which extends in the longitudinal direction of the runner, and wherein one wheel of each pair is directly drivable by a respective drive motor mounted on the chassis, and the other wheel of that pair is driven said one wheel via an endless drive chain.

46. Sizing apparatus as claimed in claim 40, wherein the rotary support is a double turntable constituted by a lower turntable and an upper turntable, the upper turntable carrying the milling arm, and the lower turntable being mounted on the chassis.

47. Sizing apparatus as claimed in claim 46, further comprising a locking bolt for detachably locking the two turntables together for preventing relative rotation therebetween.

48. Sizing apparatus as claimed in claim 47, wherein the turntables are such that the locking bolt can be used for detachably locking the turntables together in any one of a plurality of predetermined relative positions.

49. Sizing apparatus as claimed in any one of claims 1 to 48, further comprising a loading device arranged on a jib.

50. Sizing apparatus as claimed in claim 10, or in any one of claims 11 to 49 when appendant to claim 10, wherein the chassis is transversely displaceable relative to the support frame.

51. Sizing apparatus as claimed in claim 50 when appendant to claim 14, wherein the chassis is transversely displaceable by means of a pair of hydraulic rams housed within the transverse beams.

52. Apparatus for sizing a refractory-lined blast furnace runner, the apparatus being substantially as hereinbefore described with reference to, and as illustrated by, Figs. 1 to 3, Figs. 1 to 3 as modified by Figs. 4 and 5, Figs. 6 and 7, Fig. 8, Fig.

9, Fig. 10, or Figs. 11 and 12 of the accompanying drawings.