LU83399A1 - IMPROVEMENTS IN METHODS FOR RECHARGING REFRACTORIES OF METALLURGICAL CONTAINERS - Google Patents

Description

i · 3ΛΗ58

Claim In priority of (s) in ccrr.c ~ -r.-r- c * rrr-por ^ srH ^ ç) deposit l; :; tn - ^ yiSi ^ iAx / JiA .__ on _ ^. 05. > 18 80 01 under the n ° 88V 5¾ 4 \ ί'ΛΪΰ \ .ΧΚ - 1 - C 2042E / 8105.

METALLURGICAL RESEARCH CENTER -J CENTRUM VOOR RESEARCH IN DE METALLURGIE,

Non-profit association -Vereniging zonder winstoogmerk in BRUXELLES, (Belgium).

Improvements to the refilling processes of refractories of metallurgical vessels.

The present invention relates to improvements in the methods of recharging refractories of metallurgical vessels. It is especially applicable to the tap holes of steelworks converters.

The principle of refilling metallurgical vessels, well known for a long time, consists, when the refractory lining of these has become totally or locally too thin or too altered, to replace all or part of the zones in question, by new refractory which may be present in shaped form (for example bricks of suitable shape) or unshaped (for example an aggregate combined with one or more binders and suspended in a fluid); the / zones thus recharged are then subjected to cooking / Jjf if.

"- 2 - suitable in the case of uncooked materials.

In order to improve the resistance of the recharged materials and to allow the recharging operation to be carried out when there is a very high temperature inside the container, it has been envisaged to use a gaseous support for bouncing against the wall to be repair of the container, the refractory materials to be used for the repair; these materials, whether or not accompanied by a binder, are then subjected to the location of the projection, to suitable heating, for example by a torch or a burner to perfect, in good conditions, the joining of the area to be recharged.

In this spirit, several devices have already been imagined and used to carry out on-site heating of the refractory materials thus projected.

It has in particular been proposed for this purpose, by the same applicant, an improved burner, characterized in that it consists of three concentric tubes, the conduit between the j two external tubes being closed at the end on the outlet side of said device and in that it further comprises: - means for circulating between the two external tubes a refrigerating fluid, for example water, - means for passing a very oxidizing gas, preferably of l 'pure oxygen, through said device 1 inside the internal tube, - means for passing a combustible fluid, preferably gaseous, containing in suspension refractory products of appropriate particle size, all through said device in the space between the two internal x / tubes. / // τ - 3 -

Such a burner can be represented as in Figure 1 attached, and respond to the description below. This diagram is given only by way of nonlimiting example and not to scale.

On this diagram, one can locate the three concentric tubes 1, 2,3. The two external tubes 1 and 2 are used for cooling the device. This cooling is ensured by a suitable fluid, brought into the intertube space 1-2 by auxiliary conduits (4) delivering the fluid by their ends 5 themselves arranged at the end on the outlet side of the device.

The intertube space 2-3 is used for the passage of a combustible gas containing in suspension the granular refractory materials intended for recharging the wall to be repaired. This space is kept constant thanks to dividers 6 judiciously arranged.

The central duct 3 is used for the passage of oxygen; the sections subjected more to abrasion, such 7 are reinforced in thickness and in an abrasion-resistant material, for example (Mn steel). The ends on the outlet side of the said; device consist of inserts, such as 8 (copper) for cooling, 9 and 10 for replaceable copper inserts, for the 2 internal tubes.

The end sections of the tubes are advantageously lined or made up of sleeves or inserts made of a material with high heat dissipation, for example copper, these sleeves or inserts can be removable.

Furthermore, the internal sections of the internal tubes are made up and / or lined with inserts made of specially / abrasion-resistant material, for example special steels, / / hard or surface-hardened cast irons, alloys (J / I; ! * - 4 - containing appropriate elements such as Cr, Mo, W, Ni, V,

Mn, carbides of W, cermets, sintered parts, etc. The end of the internal tube can be provided with a deflector, with a vein, for example fixed and in the form of a helix.

The subject of the present invention is a process which, thanks to the use of burners of the type mentioned above, reloads, under excellent conditions, the tap holes of the steelworks converters.

It should however be understood, although the present description and the claims are focused on the use of said burners for recharging the converter tap holes,

Ique these burners can, in the context of the present invention, be used to reload any refractory wall of metallurgical container.

It is known that during their campaign, the steelworks converters undergo progressive degradation of their internal refractory lining, and especially of the refractory lining surrounding the tap hole. The latter wears differently, both on the inside of the converter and in the passage itself. In fact, on the interior side, wear is manifested by a marked flaring of the tap hole entry hole (which is the cause of a significant ironing of slag, detrimental to the quality of the metal), and in the passage by an increase in section thereof, as well as by an alteration of its straight profile. In addition, it has been observed that during successive usual reloads depositing refractory material, asymmetrically, the position of said passage progressively moves upwards of the converter, until it reaches the outer metal carcass. Added to this is the difficulty there was in remodeling in the correct place and following a correct profile *, / | this part of the converter refractory. / J / Ί.

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The method, object of the present invention as said above, makes it possible to remedy these drawbacks quickly, precisely and efficiently.

According to this method, use is made of one or two burners of the kind described above, the burner possibly having, as the case may be, at its outlet side, either an end curved substantially at 90 °, or one end slightly curved, for example 15 to 30 °.

According to the invention, the burner or burners are arranged on a support device allowing the positioning and orientation of the burners with precision relative to the neck hole! lée to be recharged, the converter itself being placed in an appropriate inclined position, preferably with the horizontal tap hole. Are then introduced into said hole, at least one of the two aforementioned burners, the most curved burner (in the case where two burners are used) is first introduced to the appropriate place, to perform the refilling the flared part of the tap hole inlet, this first burner being withdrawn from the hole if necessary after which the less curved burner is in turn introduced into the tap hole, to the appropriate place , for example the end of the hole to carry out, from the first recharge, the gradual recharging, for example from the inside to the outside of the converter.

The two burners being each also capable of turning on their longitudinal axis, even during recharging, it is thus possible to obtain radially a differential recharging which takes account of the local differences in wear observed in the refractory lining the taphole.

The recharging can be carried out by projection of the recharging materials, the burner being subjected either to a movement of rotation around its axis, or to a movement of transla-f1 // "- 6 - tion (possibly from back and forth) along its axis, or to these two movements appropriately combined.

In the case where only one burner is used, it has also been found advantageous to choose the one whose end 'on the outlet side is slightly inclined on the axis (for example 15 ° to 30 °), at arrange the converter so that its tap hole is inclined towards the inside of said converter, then carry out the recharging of the hole from the outside of it (outside side of the converter). This modality is particularly interesting in the case where the wear of the tap hole is mainly accentuated in the passage.

S

According to a first method, the burner is made to penetrate the hole, from the outside to the inside, while rotating it around its axis. It has been found that this way of proceeding makes it easier to project a refractory product onto a wall which is still fairly hot and which has not had time to be cooled for any reason whatsoever.

According to a second advantageous embodiment of this latter variant, the single burner used is kept practically outside the converter, facing and close to the orifice of its tap hole which is substantially horizontal or inclined inwards and one projects the recharging refractory on the wall to be recharged, with a pressure of the combustible gas and / or that of the oxidizing gas, so that the projected hot refractory mass progressively reaches the wall of the taphole, over its entire length, from the outside towards the inside of the converter, under the effect of said pressure, said burner preferentially remaining in rotation about its own axis. By way of nonlimiting example, a speed of the oxidizing gases / from 5 to 40 m / sec. and a refractory content / ^ / of 3 to 6 kg / Nm3 could be suitable. / V / - 7 -. ''

This modality has obvious operational advantages and allows a practically as efficient refilling of the tap hole as that obtained by means of the other variants.

-According to an interesting variant of this second method, the pressure of the oxidizing gas and / or that of the combustible gas are modified during the recharging operation, so that the projected refractory mass accurately attttigns such or such part of the passage to reload, or that reloading is carried out according to a progress ^ / determined. f dd

Claims (11)

1. Method for recharging the tap hole of steelworks converters, characterized in that the converter being inclined in the appropriate position, the worn part or parts of said tap hole are recharged, by means of at least one burner consisting of three concentric tubes, the conduit between the two external tubes being closed at the end on the outlet side of said device and further comprising: - means for circulating between the two external tubes, a refrigerating fluid, for example of water, - means for passing a highly oxidizing gas, preferably pure oxygen, through said device inside the internal tube, - means for passing a combustible fluid, preferably gaseous, containing suspended refractory products of appropriate particle size, all through said device in the space between the two internal tubes. 2. Method according to claim 1, characterized in that one introduces first of all from the outside of the converter, 'into its taphole, a burner of the aforementioned kind and the outlet end of which is curved over its longitudinal axis, at a large angle, preferably of the order of 90 °, the introduction being carried out until the burner outlet orifice is practically opposite the flared part due to wear of the orifice d entry of the taphole, in that at this time the recharging of the wall of said orifice is carried out by means of said burner, in that after having removed the burner from the taphole, a second is introduced therein burner of the aforementioned kind and whose head is! ' inclined on its longitudinal axis by an angle less than 50 ° and preferably between 10 ° and 30 °, the introduction / stopping when the burner head is in front of a ^^ / i - 9 - portion of the wall of the tap hole to be recharged and in that the said wall is then recharged by means of the said burner, for example: starting from the part already recharged, on the side of the inlet port of the tap hole, the process possibly advantageously, however, depending on the case, being limited to the use of only one of the two aforementioned burners. 3. Method according to claim 2, characterized in that at least one of the two burners, and preferably both, are subjected to rotation about their longitudinal axes during the recharging operation. 4. Method according to claim 1, characterized in that only one burner is used, preferably one whose ex-] outlet end is slightly inclined on its axis, in that the converter is arranged , so that its tap hole is inclined towards the inside of said converter, so that the hole is recharged from the outside thereof. 5. Method according to claim 4, characterized in that the burner is penetrated into the tap hole, from the outside to the inside, while rotating it around ‘of its axis. 6. Method according to claim 4, characterized in that the single burner is maintained practically outside the converter, opposite and near the orifice of the tap hole, substantially horizontal or inclined, towards the interior of the converter and in that the recharging refractory is projected onto the wall to be recharged, with a pressure of the combustible gas and / or that of the oxidizing gas so that the projected hot refractory mass progressively reaches the wall of the taphole over all its length, from the outside to the inside of the converter, under the effect of said /. -y I -ιο ί around its own axis. 7. Method according to either of claims 1 to 6 / characterized in that the oxidizing gases leave the burner with a speed between 5 and 40 m / sec. 8. Method according to either of claims 1 to 7, characterized in that the refractory content of the oxidizing gas 3 is between 3 and 6 kg / K & n. 9. A method according to either of claims 1 to 8, characterized in that the pressure of the oxidizing gas and / or that of the combustible gas are modified during the recharging operation, so that the projected refractory mass reaches precisely this or that part of the passage to be recharged, or that the recharging is carried out according to a determined progression. 10. Method according to either of claims 1 to 9, characterized in that it is implemented by means of a burner in accordance with any one of the constructive methods thereof, as stated to the description. 11. Processes as described above. Drawings: —λ— Plates Ab paoes of which rccs loses ______ d ......... ... .. i inscription ....... 3 ....... ens da claims /? .._______ c.Ciûaé descriptif J Luxsnihr. ':' n1! s 1¾. 05. ^ - '' 'Charles München