EP0226576B1 - Equipment for the remaking and repairing of high furnaces - Google Patents

Abstract

Equipment intended to the remaking and repairing of high furnaces (1) comprising a rotating feed launder (7). The equipment comprises a telescopic projection length (21) which is controlled and mounted on the rotating feed launder (7) and which may be expanded in order to reach, by the combined rotation and inclination of the feed launder (7) and the expansion of the length (21) all the points of the high furnace (1) requiring a treatment. Application to the remaking or repairing of the refractory lining of high furnaces.

Description

The present invention relates to removable equipment intended for the repair and repair of blast furnaces, in particular by gunning, in which the load distribution is carried out by a rotating chute mounted in the louver. The invention also extends to a method of repairing and repairing blast furnaces of this type.

It is known that modern blast furnaces generally include devices for charging and distributing the supplied materials (mineral, coke and fluxes) constituted by a rotating chute which makes it possible to better distribute these charges and therefore to better regulate the operation of the blast furnace.

Blast furnaces of this type, however, just like conventional blast furnaces, require repairs or repairs to the lining or refractory lining of the walls of the top of the tank in particular. These operations may be particularly necessary when the blast furnace has worked "on the periphery" causing maximum production of cast iron but also wear of the refractory lining which is very significantly greater than during a central operation of the device.

Document US-A-4 253 646 discloses a device for repairing the refractory lining of a blast furnace, which comprises a horizontal fixing device which can be introduced into a lateral opening adjacent to the upper end of the top furnace and which carries a first rotary and pivotable arm to which is articulated a second arm provided at its free end with a projection nozzle.

The device described nevertheless includes complicated and expensive drive mechanisms for controlling the various movements of the arms. Furthermore, it is necessary to assemble a complicated and bulky device before each repair operation of a blast furnace. In addition, as mentioned in the document VA-A-1 169 382 commented below, the use of the device claimed in the document US-A-4 253 646 requires the disassembly of the loading chute, when it is a blast furnace with a rotary loading chute, while this type of unloading device is increasingly used.

In addition, the above-mentioned device is intended to be introduced laterally into the blast furnace, through an opening in the wall, and cannot be used for access from above.

Document CA-A-1 169 382 discloses a device for repairing the refractory lining of a blast furnace, which comprises a horizontal member introduced by a lateral opening of the blast furnace, at the upper end thereof, a telescopic central shaft rotatably mounted to said horizontal member, drive means for the extension and retraction of said central shaft, for driving said shaft in rotation on its axis and for tilting an adjustable projection nozzle fixed at the end of said shaft median which can also be moved along the diameter of the blast furnace in this section.

Although said document refers to the device mentioned in document US-A-4 253 640, seeking to simplify it, it always uses a complicated and expensive arrangement provided with numerous controls, which is introduced laterally into the blast furnace, at the top end of it.

Document GB-A-2 034 605 discloses a spraying installation for the hot repair of metallurgical vessels, in particular an oven for implementing the DH or RH degassing process. It claims more particularly a particular characteristic of the projection lance.

The device described therein is more particularly suitable for repairing converters which are substantially different from blast furnaces.

The device described in the aforementioned document could not find an application in a blast furnace with a revolving chute and, therefore, it was necessary to seek another more suitable solution to support and guide the projection head of a conventional type.

The present invention aims to provide equipment and a method for carrying out emergency operations of extremely rapid repair and repair of a blast furnace while avoiding the need to introduce operators into the blast furnace. The object of the invention is also to allow, in particular, to carry out the necessary repairs and repairs without having to wait for the complete cooling of the blast furnace, which, of course, saves considerable time.

Another object of the present invention is to provide a new device or equipment of the aforementioned type which is suitable for a blast furnace equipped with a rotating chute, but which does not have the drawbacks of the known devices introduced laterally into the blast furnace.

These objectives are achieved by a device comprising a telescopic projection lance which is fixed to the rotating chute (namely in the latter or outside thereof). The projection lance can be deployed in order to reach, under the combined effect of the rotation and the inclination of the chute and its deployment, all the points of the blast furnace requiring treatment.

The principle on which the invention is based is therefore to combine two movements specific to the rotating chute, namely rotation and tilt with a specific movement of the lance, namely deployment, in order to be able without human intervention in the inside the blast furnace carry out the necessary operations. These operations can of course be observed. vées by an external operator using conventional devices, in particular at least one camera and a display screen arranged outside the blast furnace.

Advantageously, armored cameras, waterproof and protected by a current of fresh air, introduced inside the blast furnace, which will be mounted for example on the chute or in any other place and which will give a front view and / or in profile of the refractory projection.

Advantageously, the deployment of the telescopic lance is ensured under its own weight, a retaining force being exerted by a cable controlled from the outside. Other devices are of course conceivable.

The telescopic lance preferably consists of tubes with square section and comprises at one end of the lance a curved projection head. In said square section tubes are housed the conduits bringing to the projection head suitable materials such as dry refractory material and water in the case where it is desired to carry out a refractory gunning. The lance can of course also be used to spray other fluids or chemicals. Said lance can also be adapted for the projection of refractory materials placed in a state of prefusion at the outlet of the projection nozzle and this by various techniques, in particular by plasma, incandescence by exothermy, or blowtorch.

Advantageously, said lance is attached to the stiffening elements of the chute which brace the upper edges of the chute. If necessary, additional spacers can be added to the chute to support said lance.

According to a specific aspect, the present invention also relates to the use of the above device for the repair or repair of a blast furnace at all its points requiring treatment.

Advantageously, the repair or repair treatment is provided by working from top to bottom in the tank of the blast furnace. This way of proceeding has the advantage that the non-adherent or superfluous materials fall freely to the bottom and on the other hand that the possibly excess water which descends under the effect of gravity is incorporated into the material brought later. By working in reverse, dripping water, during the progress of the work, would destroy, by the loss of water due to gravitation, the good water-cement balance during the beginning of setting. Therefore, the last upper crowns would have a very poor quality of concrete and in particular a brittleness at the same place where very high abrasion resistance is sought.

It should be noted that the term repair or repair treatment must be understood in the broad sense and includes operations other than spraying by the technique known as gunning of cold or hot refractory materials. The lance can in particular be used to carry out a

shot blasting in order to clean the brick walls or shielding or crown of dust and adherent materials of all kinds and to update the sound body of the refractory lining before carrying out gunning.

Various characteristics and specific advantages of the invention will appear to those skilled in the art on reading an illustrative description of a particularly preferred embodiment of the invention, with reference to the accompanying drawings.

• La figure 1 représente une vue schématique partielle d'une moitié supérieure de haut fourneau avec la goulotte et l'équipement selon l'invention dans une première position.
• La figure 2 représente une vue similaire à celle de la figure 1 avec une lance en position partiellement déployée.
• La figure 3 est une vue similaire à la figure 1 avec une autre forme de réalisation de l'équipement selon l'invention.
• La figure 4 est une vue en perspective de la goulotte équipée de la lance selon l'invention.
• La figure 5 est une vue de détail en éléva- tiond'une tête de gunitage en particulier.

In these:

• Figure 1 shows a partial schematic view of an upper half of a blast furnace with the chute and the equipment according to the invention in a first position.
• Figure 2 shows a view similar to that of Figure 1 with a lance in the partially deployed position.
• Figure 3 is a view similar to Figure 1 with another embodiment of the equipment according to the invention.
• Figure 4 is a perspective view of the chute equipped with the lance according to the invention.
• Figure 5 is a detailed elevational view of a particular gunning head.

In the various figures, identical reference marks are used for the same or similar elements.

We recognize in the mouth 3 of a blast furnace represented by the general reference 1, essentially the upper left part relative to its vertical axis 5.

In the window 3, there is mounted in the conventional manner a chute 7 which is designed so as to be able to undergo a rotational movement substantially around the axis 5 and to be able to oscillate on the point of articulation 9.

The level of the upper working floor is indicated by the reference 11 and from this floor there is access to an inspection hatch 13 normally provided in the window 3 for possible repairs to the chute 7.

This inspection hatch will advantageously be used to mount the equipment of the invention. This equipment essentially consists of a telescopic lance 21 formed of square section tubes and provided at one end with a projection head 23 of curved shape. A cable 25 is wound around a winch 27, preferably a pneumatic winch, to allow the cable 25 to run smoothly.

In the embodiment of Figure 2, there is shown the telescopic lance 21 as consisting of four telescopic sections. It should be understood, however, that a different number of sections can be provided, the length of the sections and their number having to be chosen so that the lance can reach the different points subjected to the repair or repair operation.

Adequate elements, for example restraint chains, are of course provided. so that the different sections or sections of the lance 23 cannot disengage. These elements can either be constituted by stops or by chains retaining the sections so that a sufficient length of section of the lance remains in the previous section. The head 23 of the lance is designed so as to be able to direct a jet, in particular a gunning jet as shown in FIG. 2.

It is understood that by acting on the rotation and the inclination of the chute and by deploying the lance 21 adequately, it is possible to reach any desired point inside the blast furnace, the lower limit of the point which can be reached in the tank being of course determined by the possibility of deployment of the lance 21.

Advantageously, the deployment of the lance is ensured under its own weight, by unwinding the cable 25 using the winch 27. The ascent of the lance is obtained by winding the cable 25 on the winch 27.

In the interior of the lance, at least two conduits are provided, on the one hand for the supply of dry refractory materials and on the other hand for the supply of water or other fluids. Other conduits can also be provided, in particular accessory conduits for the projection of a blasting material or for the circulation of a cooling fluid.

The various flexible conduits identified by the reference 29 are taken up by return pulleys 31 and 33 in the upper part of the top and are brought to a conventional supply device (not shown).

As indicated, the process of the invention takes place (possibly after a shot peening operation intended to update the sound part of the coating, by causing a projection by gunning of an adequate refractory material) from top to bottom. bottom or, depending on the quality of the materials and the spraying method adopted, preferably from bottom to top causing the telescopic rise of the lance previously deployed.

The variant embodiment of FIG. 3 comprises a lance 21 suspended at the end of the chute 7 and held by jacks 51 preferably arranged on either side of the chute possibly after reinforcement of the latter and allowing thus modifying the angle of inclination of the lance relative to the chute. By acting on the inclination of the chute 7 and on the jacks 51, it becomes on the one hand possible to treat with great precision points or particular areas of the blast furnace and in particular to carry out interventions, emergency or routine, at great depths greatly exceeding, for example, the -6500 mm level below the blast furnace shock crown. This embodiment illustrates the great flexibility of work possible by the installation of the invention. The combined action of the inclination of the chute and the cylinders makes it possible to precisely reach the areas requiring intervention even at great depths.

The specific design of the telescopic lance is of course adapted to the function for which it is intended and to the constraints to which it will be subjected. Not only the length of the sections but also their section, their thickness, the quality of the steels chosen will be calculated according to the desired spans and the loads to be supported. If retaining chains are provided to prevent disengagement of the sections of the lance, they will also be calculated in an adequate manner while taking care to preserve a sufficient engagement for example of approximately 1 m of each section of lance in the upper element.

In Figure 4, there is shown how the lance 21 is mounted in the chute 7. This assembly is advantageously done by suspending the lance 21 to the stiffening spacers 41 and 43 which are generally permanently mounted at the ends of the chute.

If necessary, it is possible to provide additional spacers such as those indicated in 45.

The design of the projection head 23 is illustrated in FIG. S. Its essential characteristic is the fact that a rounded chamber 55 is arranged in its body which partially fills with the projected material, thereby protecting this body from wear under the effect of the admitted material. It is found that heads of this type where material-to-material contact is ensured can resist without significant abrasion for considerably longer periods of time.

This head can of course be fitted with a spout (not shown) of suitable shape and is particularly effective for working in positions similar to those illustrated in FIG. 2.

Claims (11)

1. A device intended to allow overhauling and repair of blast furnaces (1) having a revolving shoot (7) the said device comprising a telescopic blast pipe (21) equipped with a blasting head (23) characterized in that the said blasting head is fastened on the revolving shoot (7).

2. A device as claimed in claim 1, characterized in that it comprises at least one camera, arranged on the shoot (7) in the blasting axis of the blast pipe (21), and a display screen located outside the blast furnace.

3. A device as claimed in any one of the claims 1 or 2 characterized in that it comprises a holding back cable (25) controled from the outside which is fastened on the telescopic blast pipe which is extendable under its own weight.

4. A device as claimed in any one of claims 1 to 3 characterized in that the telescopic blast pipe (21) consists of tubes of square cross-section, and in that a blasting head (23) curved at the desired angle is mounted at the end of the said blast pipe (21).

5. A device as claimed in claim 4, characterized in that the conduits (29) conveying suitable materials to the blasting head (13) are ac- comodated in the said tubes of square cross-section of the blast pipe (21).

5. A device as claimed in any one of the claims 1 to 5 characterized in that the said blast pipe (21) is attached to the stiffening elements (41, 43) of the shoot (7) which brace the upper edges of the said shoot (7).

7. A device as claimed in claim 6 characterized in that additional braces are added to the shoot (7) to support the said blast pipe (21).

6. A device as claimed in any one of the claims 1 to 5 characterized in that the said blast pipe (21) is suspended on the end of the said shoot (7) by means of jacks (51) making it possible to change the angle of inclination of the blast pipe (21) in relation to the shoot (7).

9. Use of a device as claimed in claims 1 to 8 for overhauling or repairing a blast furnace.

10. Use as claimed in claim 9 characterized in that the overhauling or repair treatment is carried out by working from top to bottom in the stack of the blast furnace (1).

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