GB2046887A

GB2046887A - Apparatus for repairing degassing device for molten metal

Info

Publication number: GB2046887A
Application number: GB8007577A
Authority: GB
Original assignee: Quigley Co Inc
Current assignee: Quigley Co Inc
Priority date: 1979-03-06
Filing date: 1980-03-05
Publication date: 1980-11-19
Also published as: AU510652B3; JPS55127758U; GB2046887B; JPS5632513Y2

Abstract

An apparatus for repairing a degassing device for molten metal, comprising a container (4) for a fluidized refractory material, a pipe (6) opening into said container for connecting the air space at the upper portion of said container with a compressed air source, a refractory material supply tube (9) connected at its one end to said container at an opening in the bottom portion of said container, a compressed air inlet (7) in said supply tube for mixing compressed air with said refractory material within said supply tube, a vertical pipe (10) connected at its lower end to the other end of said supply tube, a device (12) for moving said vertical pipe up and down along the axis thereof, and an assembly of an air motor (14) and an impeller (15) rotated by said air motor, said assembly being mounted on and at the top portion of said vertical pipe (10), said rotating impeller constituting a sprayer through which the refractory material fed through said vertical pipe from said container (4) is spread together with the previously mixed air horizontally outwardly toward the cylindrical inside wall (3) of the downwardly extending vertical discharge pipe of said degassing device to be repaired. <IMAGE>

Description

SPECIFICATION Apparatus for reparing degassing device for molten metal The present invention relates to an apparatus for reparing a degassing device for molten metal, such as molten steel. More particularly, the apparatus is for repairing damaged surfaces of the inner wall of a discharge pipe which is downwardly depending from the bottom of a degassing furnace body.

According to the present invention, there is provided an apparatus for reparing a degassing device for molten metal, comprising a container for a fluidized refractory material, a pipe opening into said container for connecting the air space at the upper portion of said container with a compressed air source, a refractory material supply tube connected at its one end to said container at an opening in the bottom portion of said container, a compressed air inlet in said supply tube for mixing compressed air with said refractory material within said supply tube, a vertical pipe connected at its lower end to the other end of said supply tube, a device for moving said vertical pipe up and down along the axis thereof, and an assembly of an air motor and an impeller adapted to be rotated by said air motor, said assembly being mounted on and at the top portion of said vertical pipe, said rotating impeller constituting a sprayer through which the refractory material fed through said vertical pipe from said container is spread together with the previously mixed air horizontally outwardly toward the cylindrical inside wall of the downwardly extending vertical discharge pipe of said degassing device to be repaired.

Figure 1 shows schematically a side view of an arrangement of the apparatus of the present invention as an example relative to the downwardly depending vertical discharge pipe of a degassing device, Figure 2 shows the same arrangement as Fig. 1 but with the impeller located facing the portion of the cylindrical inside surface of the vertical discharge pipe to be repaired, Figure 3 shows schematically the sectional view of the assembly of an impeller and an air motor of Fig. 1 taken along the center line of the vertical pipe, Figure 4 is a sectional view of the impeller taken at line IV-IV on Fig. 3, Figure 5 is a sectional view of the air motor taken at line V-V of Fig. 3, and Figure 6 is a sectional view of the mover device of Figs. 1 and 2 taken along the center line of the vertical pipe.

By the use of the repairing apparatus of the present invention, a uniform and firm coating of the refractory material may be rapidly applied onto the damaged cylindrical inner wall of the downwardly depending vertical discharge pipe of the degassing device.

The present invention will be explained hereinbelow referring to an embodiment of the invention as shown in the drawings.

Fig. 1 shows an arrangement of the apparatus of the present invention in relation to a degassing device 1.

The apparatus of the present invention repairing the damaged portion the cylindrical inside wall 3 of the downwardly extending vertical discharge pipe 2 comprises a container 4 for containing a quantity of a fluidized refractory material 4'. The container 4 is sealed at the material inlet opening thereof after a quantity of the fluidized refractory material 4' is added to the container 4. The container 4 has at its upper portion a pipe 6 for connecting a compressed air source with the air space in and at the upper portion of the container 4 for introducing compressed air to act on the surface 5 of the fluidized refractory material 4' in the container 4 and discharge the fluidized refractory material 4' from the container 4 through an opening 8 provided at the bottom portion of the container 4. Preferably, a valve is provided at the opening 8.

A refractory material supply tube or hose 9 is connected to the container 4 at the opening 8, and a compressed air inlet 7 is provided at this connection to the joint portion of the refractory material supply tube 9. The compressed air inlet 7 is connected to a compressed air source so that air is introduced into and mixed with the fluidized refractory material 4' in the refractory material supply tube 9.

The other end of the refractory material supply tube 9 is connected through a connecting ring 11 with the lowermost end of a vertically supported pipe or tube 1 0. Preferably, the supply tube 9 is made of a flexible hose.

At the top end of the vertical pipe 10 is mounted an assembly 1 3 of an air motor 1 4 and an impeller 1 5.

As shown in Fig. 3, the assembly 1 3 of the air motor 14 and the impeller 1 5 is mounted on the vertical pipe 10 with the impeller 1 5 rotatable around the non-rotatable vertical pipe 10. The air motor 14 comprises a motor casing 1 8 having a cylindrical wall 20, a top wall 1 9 and a bottom wall 19', which motor casing 1 8 is fixed to the nonrotatable vertical pipe 10. Inside the motor casing 18, a runner 21 comprising a tubular shaft 24 and vanes 22 extending radially outwardly from the outer surface of the tubular shaft 24 as shown in Fig. 5 is provided on the vertical pipe 10 through radial bearings 23.Thus, the air motor 1 4 is actuatable by compressed air fed into the motor casing 1 8 through air pipe 16.

The compressed air is discharged out of the motor casing 1 8 at and from a hole 25 made through the cylindrical wall 20 of the motor casing 18.

The tubular shaft 24 extends upwardly out of the motor casing 1 8 and supports at its upper end an impeller 1 5. The impeller 1 5 has a boss 26 and an outwardly extending circular body portion 27 which has four radial flyers 28 as shown in Fig. 4. The impeller 1 5 as mounted on the tubular shaft 24 of the air motor 14 is rotated around the vertical pipe 10 for spraying the fluidized refractory material 4' with the centrifugal force acting on the fluidized refractory material 4' through radial flyers 28 as well as with the expanding force of the compressed air mixed with the fluidized refractory material 4' at the compressed air inlet 7 shown in Fig. 1.

The vertical pipe 10 is made to travel up and down by means of a mover device 1 2.

The mover device 1 2 is constructed as shown in Fig. 6. Thus, the mover device 12 is set on a floor 40 and has a mover casing 30 comprising a cylindrical side wall 31, a bottom wall 32 and a top covering 33. Within the mover casing 30, an upper deck 42 and a lower deck 43 are provided. On these decks 42, 43 are set four drivers 45, 46, 47, 48.

Each of these drivers 45, 46, 47, 48 comprises a motor 35, a driving wheel 37 and an endless belt 36 connecting a pulley on the shaft of the motor 35 with the driving wheel 37 for driving the driving wheel 37 by the motor 35. The driving wheel 37 is formed with a flange which has at its periphery an annular groove of arcuate cross-section having a radius substantially equal to that of the vertical pipe 10. When the motors 35 are energized, the driving wheels 37 drive the vertical pipe 10 in either direction as desired, if the motors 35 are made reversible. It is of course possible to make the motors 35 on the upper deck 42 to drive the vertical pipe 10 only upwardly and make the motors 35 on the lower deck 43 to drive the vertical pipe 10 only downwardly.

As the appartus of the present invention is constructed as described above, the fluidized refractory material 4' in the container 4 tends to flow out of the container 4 through the hole 8 by the action of the compressed air acting on the upper surface 5 of the fluidized refractory material 4'. The fluidized refractory material 4' flowing past the compressed air inlet 7 is mixed with compressed air and then flows through the refractory material supply tube 9 and, in turn through the vertical pipe 10 toward the impeller 1 5.

When the portion of the cylindrical inside wall 3 of the downwardly extending vertical discharge pipe 2 of the degassing device 1 is selected for repair, the mover device 1 2 for up and down movement of the vertical pipe 10 is located concentric with and beneath the vertical discharge pipe 2. The vertical pipe 10 is then shifted axially upwardly by means of the mover device 1 2 so that the impeller 1 5 is located at the same level with that of the portion of the vertical discharge pipe 2 to be repaired as shown in Fig. 2.

Next, the fluidized refractory material 4' is drawn through the refractory material supply tube 9 and the vertical pipe 10 to enter into the impeller 15, and the air motor 14 is energized by passing compressed air therethrough to rotate the impeller 1 5. Then the fluidized refractory material 4' mixed with air is sprayed around the impeller 1 5 radially outwardly toward the cylindrical inside wall 3 of the vertical discharge pipe 2 to be repaired and the fluidized refractory material 4' deposits layer upon layer on that surface.

As differentiated from the conventional method for repairing degassing device (1) wherein an L-shaped spray nozzle is provided at the top of a vertical pipe which is rotatable as well as movable up and down, illustrated in Japanese Utility Model Preliminary Publication No.51-87601/1976, the vertical pipe 10 is made axially movable but nonrotatable.

This unitary assembly of the air motor 14 with the impeller 1 5 is advantageous since the vertical pipe 10 is stationary during the spraying of the fluidized refractory material 4' and no vibration takes place in the vertical pipe 10 and no lateral movement of the impeller 1 5 occurs.

Also, the use of an impeller 1 5 causes a uniform spraying, and therefore a uniform layer, of the fluidized refractory material 4' on the cylindrical inside wall 3 of the vertical discharge pipe 2. With the conventional Lshaped spray nozzle, a locally deposited thick layer is formed on the inside surface of the discharge pipe, often causing a breaking of the deposited refractory material from the wall surface.

Further, with the present invention which uses an impeller 1 5 for the spraying, a relatively larger amount of refractory material can be deposited per unit time without causing any defect in the deposited layer, an advantage produced by the uniform deposition of the refractory material as explained above.

The compressed air as mixed with the fluidized refractory material 4' enhances the flowability of the fluidized refractory material 4' within the refractory material supply tube 9 and the vertical pipe 1 0. Such air also acts as a spraying medium for the fluidized refractory material 4' and the outlets of the impeller 1 5.

Claims

1. An apparatus for repairing a degassing device (1) for molten metal, comprising a container (4) for a fluidized refractory material (4'), a pipe (6) opening into said container for connecting the air space at the upper portion of said container with a compressed air source, a refractory material supply tube (9) conected at its one end to said container at an opening (8) in the bottom portion of said container, a compressed air inlet (7) in said supply tube for mixing compressed air with said refractory material within said supply tube, a vertical pipe (10) connected at its lower end to the other end of said supply tube, a device (1 2) for moving said vertical pipe up and down along the axis thereof, and an assembly (13) of an air motor (14) and an impeller (15) adapted to be rotated by said air motor, said assembly being mounted on and at the top portion of said vertical pipe, said rotating impeller constituting a sprayer through which the refractory material fed through said vertical pipe from said container is spread together with the previously mixed air horizontally outwardly toward the cylindrical inside wall (3) of the downwardly extending vertical discharge pipe (2) of said degassing device to be repaired.

2. An apparatus as claimed in claim 1, wherein the refractory supply tube is a flexible hose.

3. An apparatus as claimed in claim 1 and substantially as hereinbefore described with reference to and as illustrated in any one of Figs. 1 to 6 of the accompanying drawings.