WO1989001596A1

WO1989001596A1 - Apparatus for applying spray coating material

Info

Publication number: WO1989001596A1
Application number: PCT/GB1988/000661
Authority: WO
Inventors: Eustace Peter Barnes; Douglas Eric Skeldon
Original assignee: Morganite Thermal Ceramics Limited
Priority date: 1987-08-11
Filing date: 1988-08-10
Publication date: 1989-02-23
Also published as: GB8718983D0; AU2138488A; CN1031198A

Abstract

Disclosed herein is an apparatus for spraying coating material into the interior of a torpedo vessel comprising a spar (28), a boom (32) attached to the inner end (30) of the spar, a rotary spray head (86) mounted on the end of the boom, the boom being divided into at least two sections (62, 64) and (64, 66) with a joint (68) between each section, spring biassing means (70) operative across the or each boom joint to bias one section of the boom (62 or 66) to bend by pivoting away from the longitudinal axis of the adjacent boom section (64) and cable operated straightening means (72, 74, 76, 78, 80, 82 and 84) attached between the ends of the boom and mounted on the spar and operable to counter the spring biassing means to pivot said one section of boom into axial alignment with said adjacent boom section and stiffen the boom, the cable straightening means including a pulley (80) mounted on the spar about which is wound a cable (72) whereby the rotation of the pulley will cause the boom to traverse transversely to the longitudinal axis of the spar; whereby the bent boom can be introduced lengthwise into the torpedo opening and thereafter straighten to permit the spray head to be rotated and moved generally lengthwise of the vessel.

Description

APPARATUS FOR APPLYING SPRAY COATING MATERIAL The present invention relates to an apparatus for applying spray coating materials, for example refractory material, and in particular for applying such material to a vessel difficult of access through a limited opening, for example to the interior surfaces of what are known as torpedoes for transporting molten metal.

United Kingdom Patent Specification NO.2036272A (Nippon Steel Corporation) relates to apparatus for hot repair of furnace linings wherein a pivotable arm member (12) for gunning monolithic material on to a damaged part (41) of the furnace lining is supported by a collapsible arm assembly (9) that is introduced downwardly through the mouth of the furnace.

United Kingdom Patent Specification No.1162340 (AB Skanska Cementgjuteriet) discloses a device for spraying a rock wall having a holder arm (1) supporting at its outer end a spray nozzle (2), the holder arm being telescopically extendable.

United Kingdom Patent Specification No.511564 (Lechler), European Patent Specification No.0123758 (Aikoh Co.Ltd. ) and United States Patent Specification No.3690327 (Takai) all show remote refractory gunning apparatus with an articulated or pivotable spray head.

United Kingdom Patent Specification No.1525540 (Kurosaki Refractories) discloses furnace repair gunning apparatus with an extendable arm (5) and United Kingdom Patent Specification No.1522769 (Kurosaki Refractories) discloses apparatus for repairing the refractory lining of a furnace comprising a movable car carrying a vertically disposed spray pipe operable to spray a refractory material from a transverse spray nozzle on the end of the spray pipe on to the lining of a furance.

United States Patent Specification No.4272018 (Hickson) discloses an adjustable spray nozzle (6) controlled by way of a pneumatic power cylinder (18).

.None of the above discussed patent specifications relate to the particular problem of spray coating the refractory lined interior surfaces of a torpedo because of the limited access available to such a vessel. For this reason it has hitherto been the practice to employ workmen to line interior surfaces of such vessels using hand operated tools and equipment. It has consequently been necessary, before a repair operation has been carried out, to allow such a vessel to cool sufficiently to enable the workmen to enter it safely. As this takes many days, it has been a considerable waste of time during which the vessel has been unusable. Furthermore, the considerable cooling of refractory lining which has been required, followed by subsequent re-heating, has in itself been the cause of further damage to the refractory lining of the vessel. It is an object of the present invention to provide apparatus for spraying a coating material on to the interior of an elongate vessel, the apparatus being capable of being remotely controlled by a workman outside the vessel.

According to the present invention, in apparatus for spraying coating material on to the interior of an elongate vessel, the apparatus comprises a spray head; a delivery pipe for supply of coating material to the spray head; and, a spray support structure designed to be inserted into the vessel through a limited opening in a side wall thereof, the support structure including:- a spar; a boom attached to the inner end of the spar, the spray head being located on the boom and the boom being divided into at least two sections with a joint between adjacent sections; biassing means operative across the or each boom joint to bias one section of the boom to bend by pivoting away from the longitudinal axis of the adjacent boom section; straightening means operable to counter said biassing means to pivot said one section of boom into axial alignment with said adjacent boom section and straighten the boom, and means to move the spray head transversely to the longitudinal axis of the spar; whereby the bent boom can be inserted lengthwise into the vessel opening and thereafter straightened to permit the spray head to be moved generally lengthwise of the vessel.

In a preferred embodiment of the present invention the spray head is mounted to one end of the boom and a cross-head is pivoted to the inner end of the spar, the boom apparatus being journalled in the cross- head for movement transverse to said longitudinal spar axis; the biassing means is a spring and the straight¬ ening means is a cable attached to each end of the boom apparatus and tensioned by means carried by the spar, the cable acting across the pivot in opposition to the spring whereby tensioning of the cable straightens the boom; conveniently, the tensioning means mounted on the spar includes a driven pulley about which the cable is wound whereby rotation of the pulley will cause the boom apparatus to traverse through the journalled cross- head.

Usually, the spray head is mounted to be rotatable about the longitudinal axis of the boom apparatus and means are provided to move the spray nozzle from one position axially aligned with said longitudinal axis of the boom apparatus to a second position transverse to said longitudinal axis. The invention is illustrated, by way of example in the Drawings, wherein:-

Fig. 1 is a side elevation of a torpedo vessel used for conveying molten metal in a steel works; Fig. 2 is a schematic plan, illustrating the insertion of a spray head support structure, in accordance with the present invention,^' into the vessel of Fig. 1; Fig. 3 is a plan of the support structure of Fig. 2; Fig. 4 is a side elevation of the support structure of Fig. 2;

Fig. 5 is a detail elevation of a cross-head for the support structure of Fig. 2;

Fig. 6 is an underplan of a spar and cross-head for the support structure of Fig. 2;

Fig. 7 is a detail elevational view, illustrating a boom hinge; and Fig. 8 is a schematic elevation of a spray head.

Figure 1 shows a rail mounted torpedo vessel 10 and the refractory lined vessel 12 is elongate, having a cylindrical centre section 14 that tapers frusto- conically to each end 16,18. The torpedo 12 is mounted for rotation about its longitudinal axis so that a central pouring port 20 can be brought from the upstanding, transport position to a pouring position to one side or the other of the vessel. Such vessels are widely used in the steel industry for transporting molten metal to where it is required for pouring into a mould. It is, however, a considerable problem to repair the refractory lining of such a vessel, mainly because the limited access to the interior of the vessel has necessitated the work being done by workmen using hand-operated tools and equipment.

Figs. 2 to 7 illustrates spray apparatus whereby a spray head can be entered into a torpedo and remotely controlled by a workman outside the vessel. The spray head support structure is shown to have a main frame part 22 mounted on the forks 24 of a fork lift truck 26 (shown in chain-dotted lines) on which the workman carrying out the repair can sit throughout the operation. A spar 28 is pivoted to and extends forwardiy from the main frame part 22 and carries at its forward end 30 a boom assembly 32. The spar 28 is pivoted to the main frame 22 by a king pin 34 located top and bottom in bearings 36 in the main frame, for simple pivotal adjustment of the spar about the vertical axis of the king pin.

The boom assembly 32 is connected to the spar 28 by means of a cross-head, generally indicated at 38, which cross-head is pivotally connected to the forward end 30 of the spar 28 about the axis of a vertical pivot pin 40. The cross-head mounts rollers schematically shown at 42 and 44 in Fig. 3 near the opposite ends of the head and which provide mounting means for the boom assembly 32 so that the assembly can be moved longitudinally of the cross-head; as described below.

As most clearly shown by Figs. 4 and 6, the angular position of the cross-head 38 and boom assembly 32 relative to the spar 28 is adjusted about the cross- head/spar pivot pin 40 by means of a cable and pulley system wherein the free ends of a spar cable 46 are anchored one to each end of a semi-circularcable guide 48. The cable then feeds via guide rollers 50 to a drive pulley 52 mounted at the main frame end of the spar 28. Rotation of the drive pulley will cause the cable to act against the cable guide and pivot the cross-head.

The boom assembly 32, as shown by Fig. 7, comprises upper and lower rectangular

-section tubes 54 and 56 with cross bracings 58, and is formed at one end with a mounting 60, for a refractory spray head. The boom assembly is made in three parts 62,64 and 66; each hingedly connected together by a vertical pivot pin 68 that is to say a main length 62 and boom extension parts 64 and 66. A spring 70 is provided to bias a boom extension part 64 or 66 to bend away from the longitudinal axis of the adjacent boom main length 62.

The means previously referred to for longitudinally adjusting the boom assembly in position serve also to allow the movement of the boom extension 64 to a displaced position or to bring it back to a position in line with the main length 62 when required. These adjustment means are best seen in Figs. 3, 4 and 5 and are constituted by mechanism including a length of wire rope 72, a first pair of pulley wheels 74 mounted for free rotation about respective spindles upstanding from the top of the cross- head 38; a pair of guide rollers 76 mounted for free rotation between horizontal brackets on the back face of the cross-head and, a second pair of pulley wheels 78 mounted for free rotation about respective spindles upstanding from the back face of the cross-head. A tensioning pulley wheel 80 is mounted on a bracket 82 which can be adjusted in position along the spar 28 by means of a cranked handle 84. The wire rope 72, which is connected at one end to the boom extension 64, encircles one pulley of each of the pulley wheel pairs 74, 76, 78 carried by the cross-head 38, the pulley wheel 80 mounted on the bracket 82 and the other of each pulley wheel pair 74, 76, 78 carried by the cross-head and is connected at its other end to the end of the other boom extension 66 that is remote from the boom extension 64. The wire rope 72 passes the pivot pin 38 to one side thereof such that tension in the rope tends to straighten the boom. Reversible power operated means (not shown) are provided for driving the pulley wheel 80 which the wire rope encircles several times. Consequently, when the wire tope is taut, the boom is straightened and said power operated means are effective to displace the boom assembly lengthwise or longitudinally in the required direction through the cross-head.

When the bracket 82 is adjusted in position along the spar 28 by means of the cranked handle 84, to move it towards the cross-head, tension in the wire rope is released. Consequently, the boom extension part, carrying the spray head at its free end, is able to swing sideways towards the laterally displaced position in which it is shown in chain- dotted lines in Figs. 2, 3 and 7, under the influence of spring 70. The pivot 68 between the other boom extension 66 and the boom main length 62 is locked at this time so that the two boom parts are longitudinally aligned.

Referring now in particular to Fig. 2, the support apparatus just described is such that despite the relatively small size of the pouring aperture 20 in a torpedo 12 and the relatively great distance of the end walls 16, 18 of the vessel from the pouring aperture, the spray head can be brought to the required position for spraying an end and then traversed during the spraying operation so that the frusto-conical ends 16,18 and then the cylindrical surfaces 14 of the particular vessel illustrated can be spray coated. As indicated in chain-dotted lines, the boom assembly 32 can be entered into the vessel at an angle through the pouring aperture 20 (which will have been brought to a laterally disposed position,as shown). The boom assembly can then be advanced through the cross-head 38. The lateral displacement of the boom extension part 64 during this operation allows the main length 62 to be advanced through the cross-head sufficiently for its rear end 66 to clear the side of the aperture 20. This permits the spar 28 to be advanced through the aperture 20 to bring the cross-head 38 substantially to the longitudinal axis of the torpedo, allowing the boom assembly 32 ' to be brought back to its straight condition. Fig. 8 shows a spray head 86 adapted to be remotely controlled for use within a torpedo whilst the latter is still hot. The spray head includes a spray nozzle 88 formed by the free end of a length of thick walled rubber hose 90 having a helical outer spring 92 and constituting a delivery pipe for carrying refractory lining material to the spraynozzle. The other end of the rubber hose 90 is connected to a rotary coupling 94 by means of which the hose 90 is connected to a flexible supply conduit 96 for dry refractory lining material. This material is mixed with water in a mixing head 98 having a separate conduit water supply 100.

Drive means are provided for turning the swivel coupling 94 at a controlled rate, said drive means being constituted by a worm and wormwheel mechanism the worm 102 of which is drivably connected to a compressed air motor 104 and the wormwheel 106 of which is connected to the rotary coupling. As the apparatus is drawn in full lines in Fig. 8, the rotation of the rotary coupling by the driving means described traverses the spray nozzle in a circular path. However, control means 108 are provided for adjusting the angle at which the spray nozzle projects from the axis about which the rotary coupling rotates and at one extreme of its adjustment the spray nozzle 88 can extend axially of the rotary coupling, as shown in dotted line. The control means 108 constitute a drum 110 mounted on a bracket 112 carried by the rotary part of the coupling 94, a cable 114 is anchored at one end to the drum 110 and at the other end to the nozzle 88. The drum 110 has an integral ratchet head 116 acted on by a spring-loaded pawl 118. The pawl is actuated by a cam (not shown) on the stationary part of the spray h e ad so that, for each rotation of the nozzle, the drum is indexed by one tooth and the spray nozzle is consequently drawn towards the drum. A second, spring- loaded locking pawl 120 prevents the drum from unwinding in the opposite direction. The ratchd: head 116 is arranged to have some missing teeth to coincide with the actuating pawl 118 when the nozzle is directed radially outwardly and transversely to the rotation axis of the spray head; thus the nozzle can be brought from an axial position to a transverse position, where it will remain even though the spray nozzle continues to be rotated. A pneumatically operated stop (not shown) can be brought into the rotatational path of the locking pawl 120 to release the pawl, free the drum and permit the nozzle to return to its axial position (under the effect of the spring winding 92).

During the operation of the apparatus, the spray head 86 is brought into position at the axis of the torpedo, and near one end 16 or 18 as described, and spraying commences with the nozzle extending axially of the rotary coupling 94. However, as the drive means for turning the rotary coupling are operated, drum 110 is indexed round so that the nozzle 88 is brought slowly to the position in which it is shown in full lines in Fig. 8. The result is that the spiralling movement of the nozzle spray coats the substantially semi- spherical interior end surface of the torpedo in a very satisfactory manner. When the nozzle has reached substantially a right angle position so that it is spraying radially outwards, the cylindrical interior surface of the torpedo can be spray coated by the gradual retreating movement of the apparatus along the torpedo, the drive means for turning the rotary coupling continuing to operate, by rearward traversing of the boom assembly through the cross-bracket. Displacing the spar as far as possible towards the side surface of the aperture 20, enables rather more than half of the length of the vessel to be coated in a single spraying operation. The apparatus can then be extracted from within the vessel by the reverse sequence of movements.

The spray head is then mounted on the boom extension 66 at the other end of the boom apparatus 32, the pivot 68 between the extension 66 and boom main length 62 is unlocked and the pivot between extension 64 and main boom length 62 is locked so that the entire operation can be repeated in the opposite direction, enabling the interior surfaces of the other half of the vessel to be spray coated in like manner.

Various-modifications can be made and it will be understood that in its broadest aspect the invention is capable of being used for applying spray coating materials other than refractory materials.

Means other than the means described could be used for moving the boom extension to a displaced position or to bring it back into longitudinal alignment with the main length of the boom when required. For example, a wire rope positive displacement mechanism could be used for moving it in either direction at will. Alternatively, instead of its movement in one direction being brought about by means of a spring, or solely by means of a spring, the force of gravity could be employed either by the hinge being appropriately inclined or by the use of a rising butt hinge.

Claims

CLAIMS :

1. Apparatus for spraying a coating material on to the interior of an elongate vessel (12) the apparatus comprising a spray head (86), a delivery pipe (96, 100) for supply of coating material to the spray head; and a spray head support structure (28, 32,38) characterised in that the support structure is designed to be inserted into the vessel (12) through a limited opening (20) in a side wall (14) thereof, the support structure including:- a spar (28) ; a boom (32) attached to the inner end (30) of the spar, the spray head (86) being located on the boom and the boom being divided into at least two sections (62,64 or

64,66) with a joint (68) between adjacent sections; biassing means (70) operative across the or each boom joint to bias one section of the boom (62 or 66) to bend by pivoting away from the longitudinal axis of the adjacent boom section (64); straightening means (72, 74, 76,78, 80, 82, 84) operable to counter said biassing means to pivot said one section of boom into axial alignment with said adjacent boom section and straighten the boom; and, means (38, 72, 74, 76, 78, 80) to move the spray head transversely to the longitudinal axis of the spar; whereby the bent boom can be inserted lengthwise into the vessel opening and thereafter straightened to permit the spray head to be moved generally lengthwise of the vessel.

2. Spraying apparatus as claimed in Claim 1, further characterised in that the spray head (86) is mounted to one end of the boom (64 or 66) and a cross-head (38) is pivoted to the inner end (30) of the spar (28), the boom apparatus (32) being journalled in the cross-head for movement transverse to said longitudinal spar axis.

3. Spraying apparatus as claimed in Claim 1 or Claim 2, further characterised in that the biassing means is a spring (70) and the straightening means is a cable (72) attached to each end of the boom apparatus

(38) and tensioned by means (80, 82, 84) carried by the spar (28), the cable acting across the pivot (68) in opposition to the spring whereby tensioning of the cable straightens the boom.

4« Spraying apparatus as claimed-in Claim 3, when dependent upon

Claim 2 further characterised in that said tensioning means mounted on the spar (28) includes a driven pulley (80) about which the cable (72) is wound whereby rotation of the pulley will cause the boom apparatus (32) to traverse through the journalled cross-head (38).

5. Spraying apparatus as claimed in any of Claims

1 to 4, further characterised in that means (94, 102,104 and 106) are provided to rotate the spray head (86) about the longitudinal axis of the boom apparatus (32).

6. Spraying apparatus as claimed in Claim 5, further characterised in that the spray head includes a flexible nozzle (90) provided with means (108) to move the nozzle from one position axially aligned with said longitudinal axis of the boom apparatus (32) to a second position transverse to said longitudinal axis.

7. Spraying apparatus as claimed in Claim 6, further characterised in that said nozzle moving means (108) includes a ratchet driven- drum (110) mounted to the rotary part (112) of the spray head and driven by a pawl (118) which cooperates with a cam on the stationary part of the spray head, a cable (114) connecting the nozzle (88) to the drum (110) whereby rotation of the spray head causes the drum to index round and progressively draw the nozzle towards the drum.

8. Spraying apparatus as claimed in Claim 7, further characterised in that a gap is provided in the drum ratchet head (116) to coincide with said position of the nozzle (88) transverse to said longitudinal axis of the boom apparatus (32).