GB1559072A - Equipment for the application of refractory materials to the walls of metallurgical vessels eg furnaces - Google Patents

Description

(54) IMPROVEMENTS IN OR RELATING TO EQUIPMENT FOR THE APPLICATION OF REFRACTORY MATERIALS TO THE WALLS OF METALLURGICAL VESSELS E.G., FURNACES (71) We, STEEL PLANT SERVICES (ROTHERHAM) LIMITED, a British Company of Royal Insurance House, Ship Hill, Rotherham, S60 2HG, do hereby declare the invention for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particlarly described in and by the following statement:: This invention relates to equipment for the application of refractory materials to the walls of metallurgical vessels e.g., furnaces Furnaces during use are subjected to uneven wear over the face of the lining in contact with the molten metal, as a result of which certain parts of the furnace need to be repaired for otherwise the whole lining would need to be stripped from the furnace and the furnace re-lined. Such an exercise would be unwarranted in as much that over most of the furnace lining there would still be useful life in the refractories.

To increase the useful life of the furnace, areas such as the slag line are the subject of repair by the standard fettling and gunning techniques. Such techniques are, however, laborious and it is not readily possible to repair the whole of a slag line in an electric arc furnace without an operative actually entering the furnace area or by erecting a platform externally of the furnace so that an operative can project a lance into the furnace from the top. This has led to the development of a machine including a spinner at the outlet from a hopper whereby with the machine lowered into the furnace, refractory materials pass from the hopper to the spinner and are consequently ejected sideways to line the whole circumference of the furnace.Whilst such machines are adequate for repairing the slag line of the furnace lining, the indiscriminate ejection of refractory material prevents such machines being utilised to repair relatively small areas of the furnace.

According to the present invention equipment for applying refractory material to a wall of a metallurgical vessel, e.g. a furnace wall, comprises a hopper, an outlet from the hopper, nozzle means associated with the outlet from the hopper extending generally at 90" thereto and rotatably connected to the outlet from the hopper, and means for supplying air at relatively high pressure to the nozzle to entrain said material and urge said material through the nozzle outlet in the form of a spray. Thus, by having a nozzle rotatably mounted at the outlet from the hopper and extending generally at 900 thereto, continuous rotation of the nozzle such as by a suitable drive motor allows refractory material to be ejected at the whole circumference of the furnace lining to facilitate repair of the slag line.In addition to this, the nozzle can be rotated and then brought to rest at a predetermined direction and whereby refractory material can be ejected at a particular point on the furnace lining where repair needs to take place.

Whilst the hopper may contain a suitable gunning mix it is most convenient for the hopper to contain dry powdered refractory material preferably including a suitable binder and for the nozzle to be provided with a water ring so that the refractory material becomes admixed with water as it leaves the nozzle.

The nozzle may be a tube of constant cross-section or constructed as a venturi, when the position of the air inlet to the nozzle is important. It is necessary to position the end of an air pipe passing into the nozzle at a point whereby there can be no feed-back of pressure air through the outlet from the hopper and into the hopper body which could cause the ejection of the refrectory material out of the top of the hopper. Thus, the end of the inlet pipe for the air preferably lies within the nozzle with the exact position of the end deter mined by simple trial.

The outlet from the hopper may provide simple gravity feed to the nozzle although it may be preferred to provide screw feed means in the hopper outlet.

One embodiment of the invention will now be described with reference to the accompanying drawing which is a semischematic part sectional side elevation of equipment in accordance with the invention In the drawing equipment for applying refractory material to, e.g. a furnace wall is formed by a hopper 1 supported in a structural steel frame-work 2 whereby the hopper can be suspended from a crane (not shown). Mounted on the frame-work 2 is an air driven motor 3, the drive shaft 4 of which passes through the hopper 1 down a protective sleeve 5, with the drive shaft 4 emerging through an opening in the hopper wall and terminating at a drive gear 6. At the bottom of the hopper is an outlet 7 to which is rotatably connected a nozzle 8, there being a driven gear 9 secured to the rotatable nozzle and meshing with the drive gear 6 of the drive shaft 4.At the opposite side of the outlet 10 from the nozzle there is provided an air inlet 11, and towards the outlet 10 of the nozzle there is provided a water inlet 12, in the form of water ring.

Thus with the hopper 1 and supporting frame-work 2 lowered into, e.g., a furnace such that the outlet from the nozzle is aligned with the area of the furnace wall - < quiring repair, compressed air is supplied to the air inlet 11 to blow refractory material into the nozzle from the hopper 1 through the outlet 7, through the outlet 10 from the nozzle. At the same time water is supplied to the water inlet 12 so that the refractory material becomes admixed with water as it leaves the nozzle.

The nozzle 8 may be held stationary in a position where the refractory material is directed at the particular area of the furnace wall requiring repair, or the air motor can be utilised either to continuously rotate the nozzle to spray refractory material over 360" or to drive the nozzle in an oscillatory manner to spray the refractory material over an arc of a circle corresponding to the area of a furnace wall requiring repair.

In order to provide control over the texture of the refractory material sprayed from the nozzle although not shown, a metering device can if necessary be provided at the hopper outlet, such as a simple screw feed and whereby a regulated supply of refractory material is passed to the nozzle.

WHAT WE CLAIM IS:- 1. Equipment for applying refractory material to, a wall of a metallurgical vessel, e.g., a furnace wall, comprising a hopper for containing said material, an outlet from the hopper, nozzle means associated with the outlet from the hopper extending generally at 90" thereto and rotatably connected to the outlet from the hopper, and means for supplying air at relatively high pressure to the nozzle to entrain the said material and urge said material through the nozzle outlet in the form of a spray.

2. Equipment as in Claim 1 wherein, motor drive means are provided for the rotatable nozzle.

3. Equipment as in Claim 2 wherein the motor is an air motor.

4. Equipment as in any of Claims 1 to 3 wherein, water feed means to the nozzle are provided.

5. Equipment as in any of Claims 1 to 4 wherein, the nozzle is a tube of constant cross-section.

6. Equipment as in any of Claims 1 to 4 wherein, the nozzle is constructed as a venturi.

7. Equipment as in Claim 6 wherein an air pipe passes into the venturi nozzle to a point where there can be no feed-back of pressure air through the outlet from the hopper and into the hopper body.

8. Equipment as in any of Claims 1 to 7 wherein, means are provided in the outlet from the hopper to meter the flow of referactory material to the nozzle.

9. Equipment as in Claim 8 wherein, screw feed means are provided in the hopper outlet.

10. Equipment for applying refractory material to a wall of a metallurgical vessel, e.g., a furnace wall substantially as hereinbefore described with reference to the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (10)

**WARNING** start of CLMS field may overlap end of DESC **. mined by simple trial. The outlet from the hopper may provide simple gravity feed to the nozzle although it may be preferred to provide screw feed means in the hopper outlet. One embodiment of the invention will now be described with reference to the accompanying drawing which is a semischematic part sectional side elevation of equipment in accordance with the invention In the drawing equipment for applying refractory material to, e.g. a furnace wall is formed by a hopper 1 supported in a structural steel frame-work 2 whereby the hopper can be suspended from a crane (not shown). Mounted on the frame-work 2 is an air driven motor 3, the drive shaft 4 of which passes through the hopper 1 down a protective sleeve 5, with the drive shaft 4 emerging through an opening in the hopper wall and terminating at a drive gear 6. At the bottom of the hopper is an outlet 7 to which is rotatably connected a nozzle 8, there being a driven gear 9 secured to the rotatable nozzle and meshing with the drive gear 6 of the drive shaft 4.At the opposite side of the outlet 10 from the nozzle there is provided an air inlet 11, and towards the outlet 10 of the nozzle there is provided a water inlet 12, in the form of water ring. Thus with the hopper 1 and supporting frame-work 2 lowered into, e.g., a furnace such that the outlet from the nozzle is aligned with the area of the furnace wall - < quiring repair, compressed air is supplied to the air inlet 11 to blow refractory material into the nozzle from the hopper 1 through the outlet 7, through the outlet 10 from the nozzle. At the same time water is supplied to the water inlet 12 so that the refractory material becomes admixed with water as it leaves the nozzle. The nozzle 8 may be held stationary in a position where the refractory material is directed at the particular area of the furnace wall requiring repair, or the air motor can be utilised either to continuously rotate the nozzle to spray refractory material over 360" or to drive the nozzle in an oscillatory manner to spray the refractory material over an arc of a circle corresponding to the area of a furnace wall requiring repair. In order to provide control over the texture of the refractory material sprayed from the nozzle although not shown, a metering device can if necessary be provided at the hopper outlet, such as a simple screw feed and whereby a regulated supply of refractory material is passed to the nozzle. WHAT WE CLAIM IS:-

1. Equipment for applying refractory material to, a wall of a metallurgical vessel, e.g., a furnace wall, comprising a hopper for containing said material, an outlet from the hopper, nozzle means associated with the outlet from the hopper extending generally at 90" thereto and rotatably connected to the outlet from the hopper, and means for supplying air at relatively high pressure to the nozzle to entrain the said material and urge said material through the nozzle outlet in the form of a spray.

2. Equipment as in Claim 1 wherein, motor drive means are provided for the rotatable nozzle.

3. Equipment as in Claim 2 wherein the motor is an air motor.

4. Equipment as in any of Claims 1 to 3 wherein, water feed means to the nozzle are provided.

5. Equipment as in any of Claims 1 to 4 wherein, the nozzle is a tube of constant cross-section.

6. Equipment as in any of Claims 1 to 4 wherein, the nozzle is constructed as a venturi.

7. Equipment as in Claim 6 wherein an air pipe passes into the venturi nozzle to a point where there can be no feed-back of pressure air through the outlet from the hopper and into the hopper body.

8. Equipment as in any of Claims 1 to 7 wherein, means are provided in the outlet from the hopper to meter the flow of referactory material to the nozzle.

9. Equipment as in Claim 8 wherein, screw feed means are provided in the hopper outlet.

10. Equipment for applying refractory material to a wall of a metallurgical vessel, e.g., a furnace wall substantially as hereinbefore described with reference to the accompanying drawing.