GB1566932A

GB1566932A - Apparatus for applying refractory material to the inner surface of a furnace

Info

Publication number: GB1566932A
Application number: GB38585/78A
Authority: GB
Original assignee: Kurosaki Refractories Co Ltd
Current assignee: Kurosaki Refractories Co Ltd
Priority date: 1976-04-19
Filing date: 1977-04-19
Publication date: 1980-05-08

Description

(54) APPARATUS FOR APPLYING REFRACTORY MATERIAL TO THE INNER SURFACE OF A FURNACE (71) We, KUROSAKI REFRACTOR IES CO., LTD, a Japanese body corporate, of 1-1 Higashihama-machi, Yahatanishi-ku, Kitakyushu-shi, Fukuoka, Japan, do hereby declare the invention, for which we pray that a patent may he granted to us, and the method by which it is to be performed, to be particularly described in and by the follow mg statement: This invention relates to apparatus for applying a lining of refractory material to the inner surface of a furnace, e.g. for applying cement. heat-insulating material, or other insulating materials over the refractory layers of a converter or an open-hearth furnace.

In conventional lining operations, the lining material is generally produced at a location remote from the lining operation site and then is transferred to the operation site by means of a long compression supply tube. The long floor-laid tube hampers the movement of the lining device when it must move from one converter to another, resulting in an inefficient lining operation. Furthermore, since the water storage tank, refractory material tank, compressor and other equipment required in the lining operation occupy a large floor area, the operation cannot be conducted efficiently or with adequate mobility. In addition, these devices are usually located in spaced apart locations so that a central control system for the spraying apparatus is hard to achieve.

Therefore, at least several workers are required to operate the apparatus.

In the lining operation, the lining apparatus is moved to a position adjacent to the upper open end of the furnace. Subsequently, the long lance is extended into the furnace and the spray nozzle attached to the extremity of the lance is directed toward the abraded or eroded portion of the furnace lining and the desired amount of refractory material is sprayed onto the above portion so as to repair the lining.

In this case, the operator controls the lance while observing the movement thereof. However, the mere manipulation of the lance is often inadequate to insure coverage of all of the abraded portion on the furnace lining because they are not all within the range of the lance.

For example, as shown in Figure 12 of the accompanying drawings, when the spray nozzle is shifted from one abraded portion to another in some cases the lance will come into contact with the upper periphery of the furnace if the lining apparatus is kept in the same position. In these cases, the apparatus as a whole must be moved a certain distance to prevent breaking the lance. The operation to move the apparatus conventionally required that the operator get off the apparatus or shift his position on the apparatus thereby making the operation very cumbersome.

Furthermore, since the rotation of the lance is usually effected manually by an ON-OFF switching operation, it is hardly possible to apply a refractory material uniformly or efficiently onto abraded or eroded portion of a considerably large area. It is also considerably difficult for an operator to conduct two operations simultaneously, namely reciprocation and oscillation of the lance.

The present invention provides apparatus for applying refractory material to the inner surface of a furnace, comprising a transport car capable of moving on a floor, a lance with a spray nozzle from which refractory material is to be sprayed onto the inner surface of a furnace, the lance being slidably and rotatably disposed within body pivotally mounted on a support carried by the transport car, a storage tank for the refractory material, means for supplying the refractory material to the lance from the tank, and means for automatically and continuously oscillating the lance about its longitudinal axis.

The invention will be described further, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a top plan view of apparatus for lining a furnace; Figure 2 is a side view taken along the line I-I of Figure 1; Figure 3 is another side view partially broken away and taken along line II-II of Figure 1; Figure 4 is an enlarged transverse crosssectional view taken along the line III-III of Figure 3; Figure 5 is a side view taken along the line IV-IV of Figure 4; Figure 6 is an enlarged plan view taken along the line V-V of Figure 3; Figure 7 is a longitudinal cross-sectional view taken along the line VI-VI of Figure 6; Figure 8 is a schematic view of the skeleton structure of the lining apparatus showing the mechanism for steering the transport car; Figure 9 is an enlarged explanatory view showing the mounting position of the lance oscillating means: Figure 10 is a front view of a limit switch employed in the above oscillating means; Figure 11 is a cross-sectional side view of the above limit switch taken along the line VII-VII of Figure 10; and Figure 12 is an explanatory view showing the lining apparatus in two operating positions.

The illustrated lining apparatus comprises a transport car 2 provided with wheels 4 driven by hydraulically-operated motors so that the car 2 is movable both backwards and forwards. Above and substantially parallel to the transport car 2, there is a lance 8 consisting of an inner pipe 10 and an outer pipe 12.

The inner pipe 10 is provided with a spray nozzle 14 at the front extremity thereof and has the rear end thereof tightly connected with one end of a flexible hose 16 through which refractory material in either dry or wet form is supplied thereto.

The other end of the flexible hose 16 is connected to a refractory material supply source which is described later. The inner pipe 10 is slidably disposed inside the outer pipe 12 such that the lance 8 as a whole can be extended in a telescopic manner while the outer spray pipe 12 is rotatably and slidably disposed within a cylindrical body 18 which is disposed substantially at the front of the transport car 2. A poweroperated motor 20 and a gear mechanism 22 which are both attached to the cylindrical body 18 cause the rotation of the outer spray pipe 12 by way of a rotating boom 19. The rotating boom 19 forms a part of the cylindrical body 18.

This cylindrical body 18 is tiltably mounted by means of a pivot shaft on the top of a vertical support structure 24 which in turn has the bottom end fixedly secured to the upper surface of a turnable 26. A hydraulic cylinder 28 is diagonally disposed on the turntable 26 for the purpose of tilting the cylindrical body 18. This turntable 26 is supported by a plurality of roller means 30 which are disposed in a circle at the lower periphery of the turntable 26. The turntable 26 further includes a worm wheel 32 which meshes with a worm 34. The worm 34 is driven by a suitable driving means 35, such a power-operated motor, so as to rotate the turntable 26 by way of the worm wheel 32.

On the turntable 26, a storage tank 36 for powder-like refractory material and another storage tank 38 for water are mounted by means of support columns 37 such that the vertical axes of the tanks are aligned with the axis of the turntable 26. These tanks 36 and 38 are concentrically disposed one within the other such that the discharge outlet of the conical-shaped refractory material tank 36 is disposed just below the centre of the bottom of the water storage tank 38. A heat insulating shield 41 is provided in front of the tanks.

Below the outlet 40 of the tank 36, a flow regulating valve 116 is disposed (Figure 3) having a valve member 118 which regulates the amount of refractory material to be supplied to the flexible hose 16. The flow regulating valve 116 has an opening at the lower end thereof which, in turn, communicates with the flexible hose 16 through which the refractory material is charged to the inner spray pipe 10.

In order to give flow energy to the refractory material which passes through the flexible hose 16 and the inner spray pipe 10, an air jet gun 136 is provided at the lower end of the flow regulating valve 116 disposed opposite to the opening 134. This air jet gun may be provided at any suitable position of either the flexible hose, the lance, or the spray nozzle.

The water storage tank 38 has a water outlet 138 at the bottom thereof which is connected to one end of a cooling water supply tube 140. The cooling water supply tube 140 has its other end connected to an inlet opening 142 formed in the outer pipe 12 at a location so that the water charged into the lance 8 cools the entire lance 8 which is subjected to high temperature heat radiation during the spraying operation.

The outer pipe 12 has another water outlet opening 144 which is connected to one end of a warm water return tube 146 wherein the water warmed during the circulation thereof within the lance 8 is discharged into the return tube 146 by way of the outlet opening 144.

The return tube 146 has its other end connected to the flexible hose 16 at the middle thereof by way of a three-port valve 148 wherein the warmed water which passes through the return tube 146 is mixed with the powder-like refractory material to produce refractory material in a wet slurry form which is charged into the inner pipe 10 by way of the flexible hose 16.

At the rear of the transport car 2, an air compressor 150 is provided which supplies compressed air to the air jet gun 136, the water storage tank 38, the refractorymaterial storage tank 36 and other parts of the apparatus which require compressed air.

A diesel engine 151 for moving the transport car 2 is also mounted at the rear portion on the transport car 2 along with its radiator 153. This air compressor 150 and the diesel engine 151 are both protected from dust and the like by a cover means 152.

In Figure 4 and Figure 5, the mechanism to slidably move the outer pipe 12 relative to the tiltable cylindrical body 18 is shown wherein each roller shaft 154 which fixedly carries a pipe-propelling roller 156 and a spiral gear 158 in series has both ends thereof journalled by ball bearings 160 which, in turn, rest within openings formed in the side walls of a casing 162. A spiral gear 164 which is fixedly mounted on a drive shaft 166 of a power-operated motor 168 is meshed with spiral gears 158 so that the actuation of the motor 168 causes the rotation of the pipe-propelling rollers 156 which, in turn, move the outer pipe 12 forward or backward within and relative to the cylindrical body 18.

Pressure to pinch the outer pipe 12 by the two opposing rollers 156 is adjusted by a bolt and nut means 170 disposed adjacent each ball-bearing 160.

In Figure 6 and Figure 7, the mechanism to slidably move the inner pipe 10 relative to the outer pipe 12 is shown, wherein each of a pair of parallely-disposed roller shafts 172 is integrally provided with a second pipepropelling roller 174 and has both ends Journalled by ball bearings 176 which rest in openings formed in the side walls of a casing 178. Each roller shaft 172 is further provided with a spiral gear 180 at the extension adjacent to one journalled portion thereof.

A spiral gear 182 which is fixedly mounted on a rotating shaft 184 of a power-operated motor 186 is meshed with spiral gears 180 so that the actuation of the motor 186 causes the rotation of the second pipe-propelling rollers 174 which pinch the hose 16 which, in turn, slidably moves the inner pipe 10 forward or backward within and relative to the outer pipe 12.

That the second pipe-propelling rollers 174 pinch the flexible hose 16 can be observed from Figure 7. When the above rollers 174 are rotated by the activation of motor 186, the flexible hose 16 which is now depressed in an elliptical hollow cross section is moved longitudinally in either forward or backward direction due to the friction at the inter-surface of rollers 174 and flexible hose 16.

As described previously, since the hose 16 is connected with the inner pipe 10, the inner pipe 10 moves backwards or forwards longitudinally along with the flexible hose 16. The casing 178 is also provided with two opposing side rollers 188 which rotatably come into contact with the expanded or distended round side of the hose 16 so as to guide the hose 16. The pressure to pinch the flexible hose 16 by the two opposing rollers 174 is adjusted by a bolt and nut means 190 disposed above each ball bearing 176. Spiral gears 180 and 182 are protected from dust or the like by a cover means 192 which is fixedly attached to the casing 178.

Referring to the means for controlling the apparatus, shown in Figure 8, a steering wheel 194 which steers the transport car 2 hydraulically by manipulating the rear wheels 4 is disposed adjacent to the upper portion of the refractory-material storage tank 36. The mechanism to steer the transport car 2 has the following construction.

In Figure 8, two lugs 196 are attached to respective vertical runs of an endless chain 198 which extends between a shaft 200 of a steering handle 194 and a follower shaft 202.

These lugs 196 are connected with a hydraulic power steering unit 204 by means of control wires 206. This power steering unit 204 which can steer the rear wheel 4 has one end connected with a rear-wheel steering link 208 and the other end pivotally secured to the frame of the transport car 2. Referring to other parts of this mechanism, numeral 210 indicates a control lug to which control wires 206 are connected, numeral 212 indicates casing tubes which slidably enclose the wires 206 and numeral 214 indicates a hollow rotary shaft for running the electric connections and hydraulic circuits as well as the control wires.

The construction of oscillating means for automatically and continuously oscillating the lance is now described hereinafter in conjunction with Figure 9 through Figure 11, especially Figure 9 which shows the detail thereof.

Two spaced-apart circular ring plates 378a and 378b are formed into the outer pipe 12 adjacent to the pivot pin which tiltably connects the cylindrical body 18 to the support column 24. Each ring plate 378a or 378b has a plurality of contacting pads 380a or 380b secured equidistantly circumferentially on the sides thereof which faces the corresponding side of the other ring plate. A fork-lever-shaped limit switch 382 which is provided with two pressure detecting levers 384, 386 is fixedly mounted on the top of the cylindrical body 18 such that one detecting lever 384 is disposed in the rotational path of the row of contacting pads 380a while detecting lever 386 is disposed in the rotational path of the row of connecting pads 380b.

The limit switch 382 which is especially applicable to the oscillating means of this embodiment further comprises contact rollers 388 and 390 attached to respective ends of the levers 384 and 386 and spring means 392 which tends to position the levers 384 and 386 in alignment with the body of the limit switch 382 unless no contact pressure is applied to the contact rollers 388 and 390.

When the outer pipe 12 is rotated relative to the cylindrical body 18 by the actuation of the motor 20 and gear mechanism 22, the contacting pad 380a disposed on the side of one ring plate 378a comes into contact with the corresponding contact roller 388 of the limit switch and subsequently rotates the pressure detecting lever 384. When the lever 384 is rotated 90 degrees, the limit switch 382 initiates the rotation of the outer pipe 23 in the reverse direction.

The continued reverse rotation then causes the contacting pad 380b on the side of ring 378b to contact with the corresponding contact roller 390 of the limit switch 382, and subsequently the limit switch 382 stops the reverse rotation after rotating the lever 386 by 90 degrees and starts the rotation of the outer cylindrical body 12 in the previous or first direction.

In this manner, the lance is oscillated continuously, with a predetermined oscillating angle.

In Figures 1 to 3, the spray nozzle 14 which has its opening directed in an upward direction is oscillated a desired angle for applying the refractory material onto the inner upper portion of the furnace lining uniformly. However, it must be noted that the oscillating device provides the above oscillating movement of the lance regardless of the direction of the spraying opening of the spray nozzle. Namely, when the inner lower portion of the furnace lining is required to be repaired, the spray nozzle must be directed from the upward position to the downward position.

In this case, the supply of electricity to the limit switch 382 is interrupted so as to energize the limit switch 382 even when its contact roller come into contact with the contact pad by the rotation of the upper pipe 12. For facilitating the above rotation of the outer pipe 12 and also for preventing the breaking of the limit switch 382, the limit switch 382 is provided with two auxiliary pivot shafts 396 and 398 and a common shaft 400 which pivotally connects corresponding proximal ends of the two rightangled levers 384 and 386.

Each auxiliary pivot shaft is constructed such that it allows only one-way pivoting of the pressure detecting level.

Due to the above construction, even when the vertically disposed contact roller of the inoperative limit switch 382 is pressed rearwardly by the trains of contacting pads 380a on one side of the ring-like plate 378, the outer pipe 12 is rotated without breaking the lever 384 since the rotation of the lever 384 on the auxiliary shaft 396 allows the advancement of the above contacting pads.

Accordingly, since the lance is capable of oscillating in addition to rotating, tilting and sliding, the spraying operation by the lining apparatus of this invention is further enhanced. The manner in which the apparatus is operated is as follows.

The powder-like refractory material is discharged from the hopper-like storage tank 36 (to which compressed air is supplied from the air compressor 150) and the flow amount is regulated by the flow regulating valve 116. The discharged refractory material is conveyed through the flexible hose 16 with flow energy applied by the air jet from the air jet gun 136. The powder-like material subsequently passes through the lance 8 and eventually is sprayed from the spray nozzle 14.

If the refractory material is required in a wet slurry form, the water which is supplied to lance 8 from the water storage tank 38 for cooling the lance 8 is available. Namely, the cooling water is discharged from the water storage tank 38 by compressed air which is supplied from the air compressor 150. The cooling water then passes through the supply tube 140 into the lance 8.

The water which is warmed during the cooling operation in the lance is discharged from the outlet 144 and passes through the warmed water return tube 146 and reaches the three port valve 148. By opening the three port valve 148, the powder-like refractory material from the refractory-material storage tank 36 and the warm water from lance 8 are mixed together forming refractory material in a wet slurry form at the junction where the return tube 146 and the flexible hose 16 meet. The thus produced slurry-like refractory material is supplied to the lance 8 and finally is sprayed from the spray nozzle 14 onto the inner surface of the furnace.

In the above operation, the spray pipe 8 is manipulated by the rotating mechanism, the feeding mechanism, the tilting mechanism and the turntable 26 such that the spray nozzle 14 secured to the extremity of the lance 8 is directed toward the abraded portion of the inner surface of a furnace.

After above positioning of the spray nozzle 14, the lance 8 is automatically oscillated by a desired rotating angle with the oscillating means disclosed heretofore.

Accordingly, the apparatus described above has the following advantages.

1) Since the lance 8 can be automatically oscillated, the spray nozzle can fully and easily cover the abraded or eroded portion of the inner surface of a furnace which has, in general, a considerable area.

2With the conventional apparatus, it is extremely difficult for an operator to effect two operations such as reciprocation and oscillation of the lance simultaneously.

Since the oscillating operation is conducted automatically in the above-described apparatus, the operator can easily effect other operations, resulting in the improvement of the spraying operation.

3) Since the spray nozzle is oscillated, refractory material is uniformly applied onto the entire area of an abraded portion of a furnace.

4) Since the oscillating angle can be adjusted, the optimal amount of refractory material can be sprayed onto the above abraded portion.

Attention is directed to our application No. 16225/77 (Serial No. 1566931), from which the present application has been divided.

WHAT WE CLAIM IS: 1. Apparatus for supplying refractory material to the inner surface of a furnace, comprising a transport car capable of moving on a floor, a lance with a spray nozzle from which refractory material is to be sprayed onto the inner surface of a furnace, the lance being slidably and rotatably disposed within a body pivotally mounted on a support carried by the transport car, a storage tank for the refractory material, means for supplying the refractory material to the lance from the tank, and means for automatically and continuously oscillating the lance about its longitudinal axis.

2. Apparatus as claimed in claim 1, wherein the oscillating means comprises: two spaced apart ring-like plates mounted on the lance adjacnt to one end of the body; a number of circumferentially equidistant contact pads secured to the circular side of one ring-like plate which faces the corresponding side of the other ring-like plate, the said corresponding side also having a number of contact pads secured thereto; and a limit switch mounted on the body and provided by two contact levers each of which is adapted to contact the contact pads of the corresponding side of the corresponding ring-like plate so as to switch on and off the limit switch so as to cause rotation of the lance relative to the body in alternately opposite directions.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. After above positioning of the spray nozzle 14, the lance 8 is automatically oscillated by a desired rotating angle with the oscillating means disclosed heretofore. Accordingly, the apparatus described above has the following advantages.