FR2568361A1 - EQUIPMENT FOR ALLOWING REFURBISHMENT AND REPAIR OF BLAST FURNACES COMPRISING A ROTATING CHUTE AND METHOD OF REFURBISHING AND REPAIRING BLAST FURNACES USING SUCH EQUIPMENT - 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

Equipment intended to allow the repair and repair of blast furnaces comprising a rotating chute and process for the repair and repair of blast furnaces using such equipment.

 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 loading and distributing the supplied materials (ore, wedge and fluxes) constituted by a rotating neck which allows a better distribution of these loads and therefore better regulating the progress from 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 apparatus.

 The present invention aims to provide equipment and a method for carrying out emergency operations for 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 make it possible 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.

 These objectives are achieved by equipment comprising a controlled telescopic projection lance which is mounted on the revolving chute (namely in this one or outside of it), which can be deployed with a view to reaching, under the combined effect of rotation and tilting of the chute and deployment of the lance, all 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 neck, namely rotation and inclination with a specific movement of the lance, namely deployment, in order to be able without human intervention in inside the blast furnace carry out the necessary operations.

These operations can of course be observed by an outside operator using conventional devices, in particular at least one camera and a display screen arranged outside the blast furnace.

 Advantageously, armored cameras, watertight 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 is preferably made up of tubes with a square section and includes on the outside of the lance a curved projection head. In said tubes with a square section are housed the conduits bringing to the projection head suitable materials such as material. dry refractory and water if you want to perform 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 of the present invention, a product is provided for repairing or repairing a blast furnace comprising a revolving chute, characterized in that equipment of the type described in the neck is mounted and ensures the treatment of repair or repair desired by associating with the proper movements of the chute, a deployment movement of the lance.

 Advantageously, the repair or repair treatment is provided by working from top to bottom in the tank of the blast furnace. This procedure 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 friability in the same place where very high resistance to abrasion 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 refractory materials, cold or hot. The lance can in particular be used to carry out a blasting in order to clean the walls of bricks or shielding or crown of dust and adherent materials of all kinds and to update the healthy body of the refractory lining before carrying out a guniting.

 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.

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.

 FIG. 2 represents a view similar to that of FIG. 1 with a lance in the partially deployed position.

 Figure 3 is a view similar to Figure 1 with another form of relaying 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 detail view in elevation of a
gunning head in particular.

 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 retaining 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 chalnes 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 by 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, in great depth greatly exceeding for example the level -6500 mm 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 reach the areas requiring intervention even at great depth.

 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 dislocation of the lance sections, they will also be calculated adequately, taking care to preserve a sufficient engagement for example of approximately 1 m from each lance section in the upper element.
In Figure 4, there is shown how the lance 21 is mounted in the chute 7 This mounting is advantageously made ep 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. 5. 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.

 Although a preferred embodiment of the invention has been shown, it should be understood that many alternative embodiments remain possible.

These variants are in particular possible in terms of the techniques used for the execution of repair and repair operations within the meaning of the invention. Variations are also possible in terms of the design of the equipment itself, provided that the functions described are carried out.

Claims (10)

Claims  1. Equipment intended to allow the repair and repair of blast furnaces (1) comprising a rotating chute (7), characterized in that it comprises a controlled telescopic projection lance (21) which is mounted on, the rotating chute ( 7) and which can be deployed in order to reach under the combined effect of the rotation and the inclination of the chute (7) and the deployment of the lance (21), all the points of the blast furnace (1) requiring treatment.  2. Equipment according to claim 1, characterized in that it comprises at least one camera preferably arranged on the chute (7) in the axis of projection of the lance (21) and a display screen arranged outside from the blast furnace.  3. Equipment according to any one of claims 1 or 2, characterized in that the deployment of the telescopic lance (21) is ensured under its own weight, a retaining force being exerted by a cable (25) controlled from the outside.  4. Equipment according to: any one of claims 1 to 3, characterized in that the telescopic lance (21) consists of tubes with square section and in that a curved projection head (23) at the desired angle is mounted at the end of said lance (21).  5. Equipment according to claim 4, characterized in that in said tubes with square section of the lance (21) are housed the conduits (29) bringing to the projection head (13) suitable materials.  6. Equipment according to any one of claims 1 to 5, characterized in that said lance (21) is attached to the stiffening elements (412 43) of the chute (7) which brace the upper edges of said chute (7).  7. Equipment according to claim 6, characterized in that additional spacers are added to the chute (7) to support said lance (21).  8. Equipment according to any one of claims 1 to 5, characterized in that said lance (21) is suspended at the end of said chute (7) and that jacks (51) allow to modify the angle of inclination of the lance (21) relative to the chute (7).  9. A method of repairing or repairing a blast furnace (1) comprising a rotating chute (7), characterized in that an equipment according to any one of claims 1 to 8 is mounted on the chute (7) and provides the desired repair or repair treatment by associating the movements of the spout with a movement for deploying the lance (21).  10. Method according to claim 9, characterized in that the repair or repair treatment is carried out by working from top to bottom in the tank of the blast furnace (1).