EP2718468B1 - Assembly of a flap and a valve for equipment for loading a shaft kiln - Google Patents

Description

Technical area

The present invention relates to a trap and valve assembly for a charging installation of a shaft furnace, such as a blast furnace, and more particularly to the flap and valve assembly used in such a device for, on the one hand, allow the control of the loading of the furnace in solids and on the other hand to avoid gas leaks.

State of the art

Various types of tank furnace charging installations, in particular blast furnaces, are already known. Of these, "Bell less top ®" type installations are now commonly used, for their ability to better control kiln loading and load distribution. In addition, the sealing system used in these installations makes it possible to ensure a better seal against gases contained under pressure in the blast furnace tank, in particular by virtue of the functional dissociation between on the one hand the organs intended to ensure the sealing and on the other hand the organs intended to control the introduction of solids into the oven.

Such systems, known for example by US 4,514,129 or WO 2010/081810 , generally comprise a pivoting hatch closure device, called a material trap, for sealing one or more hoppers of material and to control the material flow rate when opening the hatch. This hatch device may comprise a single flap or two flaps pivoting in opposite directions.

These systems also include a sealing valve, located below the hatch, to prevent the escape of gas blast furnace to the outside thereof. In the closed position, this valve is supported from below against a fixed seat secured to the trap and flap assembly.

The material trap and the seal valve are mounted on a body of the trap and flap assembly, to which is connected a hopper of material solid. This body comprises a central passage of substantially vertical axis through which the solid material falls inside the blast furnace on a distribution chute, according to the technique of the Bell-less top ® system.

In the closed position, the material trap ensures the support of the solid material charge contained in the hopper and the valve ensures gastightness.

In the open position, during the introduction of material into the blast furnace, the material trap allows, when brought into the open position by pivoting, the descent of the material. The seal valve is then completely eclipsed out of the material path, so that the surfaces of the valve sealing the gas are not damaged by the solids when they fall into the central passage. When loading, the seal valve is first opened, by pivoting to completely clear the passage, before opening the solid feed hatch.

Typically, the pivot axis of the sealing valve is substantially perpendicular to the pivot axis of the flap of the door, or the parallel axes of pivoting flaps. The pivot control of the hatch and the valve is provided by respective actuators fixed to the body of the flap and valve assembly. These actuators, which may be of electrical or hydraulic type, such as motors with reducers or cylinders, respectively pivot the hatch or the hatch flaps and the valve, by transmission shafts passing through the wall of the body and which are guided in rotation on this body by bearings provided with sealing means.

In currently known systems, the bearings are fixed directly on the body of the flap and flap assembly. The shutters and / or flaps are secured to said trees, inside the body, by arms. When it is necessary to intervene on the hatch or the valve for repair or replacement, or repair of the seal, it is necessary to intervene inside the body. The personnel intervening enters this body through a trap door for this purpose in the body wall and performs its intervention in a confined space, and also in an atmosphere rendered hazardous by heat and the presence of blast furnace gas that remain despite the temporary stopping of the operation of it. This judgment is necessary for such interventions, and the duration of these leads implicitly to a loss of production.

Object of the invention

The present invention aims to remedy the problems described above and aims in particular to provide a trap and flap assembly to minimize the duration of these interventions. It also aims to improve the conditions of intervention on hatches and valves and their pivoting drive members, for a better reliability of the interventions and an improvement of the working conditions of the personnel. It is also intended to facilitate the complete replacement of a valve assembly or hatch with the associated actuators, by a similar new or previously renovated, or by a functionally equivalent assembly but having for example a different construction.

General description of the invention

With these objectives in view, the invention relates to a flap and valve assembly for a charging device of a shaft furnace, such as a blast furnace, having a body inside which is placed at least such a hatch or such a valve, pivotally driven by an actuator located outside the body and connected to the hatch or valve by a connecting shaft guided in a fixed bearing relative to the body.

According to the invention, the flap and valve assembly is characterized in that the bearing and the actuator are mounted on a removable door closing an opening which is formed in the wall of the body and whose dimensions are determined so that the trap or the valve may be extracted transversely to the axis of the body through said opening.

Incidentally, by said movement transverse to the axis, it includes a movement of the door, and the extraction of the hatch or valve in a direction perpendicular to the axis of the body, but also in a direction inclined by report to this axis. Moving the door, and the extraction of the hatch or valve is in a rectilinear direction in a radial plane passing through the axis of the body.

Thanks to the invention, each module comprising a hatch or valve with its actuator and its associated motion transmission means, can be detached from a body part and extracted from it, thus allowing either a complete replacement by a previously prepared module, ie a direct intervention on the module extracted, but then located in a more spacious environment and offering better working conditions.

In the systems of the prior art, an intervention to be performed on a hatch or valve can be performed only inside the body. If it is necessary to intervene on the motion transmission means, for example on the shaft connecting the valve, or the hatch, to its actuator, it is necessary to first penetrate inside the body to dismount. in advance the valve or the hatch and the arm that binds it to the shaft, before being able to extract said shaft to the outside. Compared to that, the invention makes it possible to perform all these operations without any intervention inside the body.

In the case of a complete replacement, the replacement module can be an identical new or renovated module, and this replacement ensures a time of intervention, and therefore production stop, reduced to a minimum. Alternatively, the extracted module is made available outside the body, on a working floor where the staff has a work surface very much greater than the confined space of the interior of the body. All the operations of replacement or repair of the various parts are greatly facilitated, and achievable in highly improved visibility conditions, the interventions can be performed for example under natural lighting to facilitate the detection of deterioration of hatches or valves and their repair. In addition, it is not necessary to disconnect the electrical or hydraulic supply circuits of the actuators, which also simplifies the required interventions.

In addition, the access to the interior of the body and the visibility are greatly improved because the hatches and flaps can be extracted completely, and no longer constitute obstacles to a good vision of the interior of the body, nor to movements of personnel likely to intervene inside the body.

The invention also eliminates the risk that a false maneuver causes a pivoting valves or traps while staff would be inside the body.

According to a particular arrangement, the door is slidably mounted relative to the body, so that, after separation from said body, the entire module can be extracted by simply sliding outwards, in a substantially radial direction with respect to the body. general axis of the central passage formed in the body. Preferably for this purpose, the assembly comprises substantially horizontal guide rails, or slightly inclined, which are preferably fixed on the body, permanently or removably, and the door has slides or carriages adapted to move on the rails, in an extreme position where a stop prevents any clearance off the rails. The length of the rails is determined so that the module can be moved over a distance at least sufficient to ensure total extraction of the valves or hatches out of the body. It is then possible to intervene on any organ of the module, while it remains supported on the rails. It is also possible to combine the translation of the module, during its extraction, with a certain pivoting thereof, so for example to facilitate the passage of the hatch or valve through the opening.

According to an alternative arrangement, making it possible to overcome the congestion of the aforementioned rails if need be, the doors comprise connection means for fixing therein, permanently or temporarily, a dismounting arm, comprising a counterweight, designed to allow the handling of each module by a lifting device. The disassembly arm and its counterweight comprise gripping rings for attaching the module to the lifting device therethrough, ensuring the equilibrium of the module so that it can be extracted from the body substantially horizontally, or at least in a position ensuring the free passage of the valve or hatch through the opening in the wall of the body.

Brief description of the drawings

• Fig. 1: une vue en perspective d'un ensemble conforme à l'invention, en position d'utilisation ;
• Fig. 2: une vue similaire à la figure 1, dans laquelle les deux modules sont en position de retrait hors du corps ; et
• Fig. 3: une vue une vue en perspective d'un ensemble conforme à l'invention, selon un deuxième mode de réalisation, les deux modules étant en position de retrait hors du corps.

Other features, features and advantages of the invention will become apparent from the detailed description of some advantageous embodiments presented below, by way of illustration, with reference to the accompanying drawings. These show:

• Fig. 1 : a perspective view of an assembly according to the invention, in use position;
• Fig. 2 : a view similar to the figure 1 wherein both modules are in the retracted position out of the body; and
• Fig. 3 : A view a perspective view of an assembly according to the invention, according to a second embodiment, the two modules being in the retracted position outside the body.

Description of a preferred execution

The trap and flap assembly shown in figures 1 and 2 comprises a body 1 providing a central passage A, substantially vertical axis A, for the blast furnace loading materials and provided with an upper flange 12 and a lower flange 12 'intended for fastening the body to the liner; charging installation of said blast furnace, not shown. It comprises a material trap module 2 and a seal valve module 3, arranged substantially offset by 90 ° about the axis A.

In the example shown, the material trap module 2 comprises a hatch 21 with two flaps 211 pivoting in opposite directions from one another. Each flap is carried by an arm 22, the two arms 22 being mounted on the ends of transmission shafts, with parallel axes 23, the shafts being mounted in bearings grouped in a set of bearings 24, and pivotally driven by inverse directions by an actuator 25 of a type known per se. The material trap module could also have only one pivoting flap.

The bearings 24 and the actuator 25 are mounted on a door 26 adapted to close sealingly, for example by a flange system 261, an opening 13 formed in the wall of the body 1, the dimensions of the opening 13 being determined in order to be sufficient to allow the passage of the entire hatch with its control arms assembled on the shafts 23, in their position of current use. That is to say, as we can see figure 2 , the hatch 21 can pass freely into the opening 13 when the module 2 is moved radially outwardly of the body, without the need to disassemble the flaps or the arms beforehand.

In the embodiment of figures 1 and 2 , parallel rails 14 are fixed on the body 1, on either side of the opening 13, and the door 26 comprises carriages 262 adapted to roll or slide on the rails 14 so as to guide the module 2 in translation on the rails in a radial direction. The carriages are made and arranged so that the weight of the entire module is supported by the rails and that the module is guided on the rails avoiding any risk of tipping, which could result from the cantilever created by the hatch. In addition, stops 141 are provided on the ends of the rails to avoid any risk of excessive sliding of the module 2.

The sealing valve module 3 is made in a manner similar to the module 2. It comprises a pivoting valve 31 carried by an arm 32 mounted on the end of a transmission shaft, with an axis 23, this shaft being mounted in a bearing 34, and pivotally driven by an actuator 35, of a type known per se.

The bearing 34 and the actuator 35 are mounted on a door 36 adapted to seal, for example by a flange system, an opening 15 formed in the wall of the body 1, the dimensions of the opening 15 being determined from so as to be sufficient to allow the passage of the assembly of the valve 31 mounted on its control arm 32 and assembled on the shaft 33, in their position of current use. That is to say that the valve 31 can pass freely into the opening 15 while remaining fixed on the arm 32 and thus linked to the door 36, when the module 3 is moved radially outwardly of the body.

As for the module 2, parallel rails 16 are fixed on the body 1, on either side of the opening 15, and the door 36 comprises carriages 362 adapted to roll or slide on the rails 16 so as to guide the module 3 in translation on the rails in a radial direction. The carriages are made and arranged so that the weight of the entire module is supported by the rails and that the module is guided on the rails avoiding any risk of tipping, which could result from the cantilever created by the valve 31. In addition, stops 161 are provided on the ends of the rails to avoid any risk of excessive sliding of the module 3.

In the current operating position of the blast furnace, the modules 2 and 3 are assembled by clamping the doors 26 and 36 on the body 1, at the periphery of the respective openings 13, 15, as shown figure 1 . When it is necessary to intervene on any organ of one of the modules, located inside the body, simply unclamp the door and slide the complete module on the rails, until clear the door completely or the flapper out of the body as shown figure 2 . It is then possible and easy to intervene on any element of the module to repair or replace it. It is also possible to easily remove the complete module, by releasing it from its rails by any suitable handling means, to replace it with another similar module.

The embodiment shown figure 3 is particularly intended for installations where it would not be possible to mount guide rails as in the embodiment described above.

In this case, the modules 2 and 3 are made identically to what has been described above, but there are no guide rails for supporting and sliding these modules. As a result, additional lifting means will have to be used. In order for the flap or flapper to pass through the opening of the body without hitting or getting stuck in the opening, it is necessary to maintain the proper orientation of the module, ie the plane of the door remaining substantially vertical, or the general direction of the pivot axes of the valve or the trap remaining substantially horizontal. To maintain this general orientation of the module during its extraction, and thus avoid a tilting caused by the cantilever generated by the hatch or the valve, a handling arm 5, 6 is fixed on the door 26, 36 by fixing lugs 51, 61, in a fixed or removable manner, and the arm comprises a counterweight 52, 62. The position of the lifting rings, or the like, on the module and the arm, and the weight of the counterweight, are predetermined to ensure balancing the assembly, and maintaining in the proper position of removal or replacement of the modules, as shown in FIG. figure 3 .

The invention is not limited to the embodiments described previously only by way of example. In particular, it can be applied to other types of hatches or valves, and other provisions thereof on the body of the trap and flap assembly.

Claims (6)

1. Hatch and valve arrangement for a charging installation for a shaft furnace, such as a blast furnace, said arrangement comprising a housing (1), inside which is located at least one hatch (21) and/or a valve (31), caused to pivot by an actuator (25, 35) located outside the housing and connected to the hatch or valve by a linking shaft guided in a bearing that is fixed with respect to the housing,
   characterised in that
   the bearing (24, 34) and the actuator (25, 35) are mounted on a detachable door (26, 36) that seals an opening (13, 15) made in the wall of the housing (1) and whose dimensions are determined such that the hatch or the valve can be withdrawn transversely to the axis of the housing through said opening;
   the door, the hatch or the valve and its actuator and its associated means for transmitting movement, together constitute a module (2, 3) that is detachable in one piece from the housing (1); and
   said module (2, 3) is designed to be extracted in one piece from the housing (1).
2. Hatch and valve arrangement according to claim 1, characterised in that the door (26, 36) is slidingly mounted with respect to the housing (1), such that after detachment from said housing, the complete module can be removed by sliding towards the exterior.
3. Hatch and valve arrangement according to claim 2, characterised in that it comprises essentially horizontal or slightly inclined guide rails (14, 16), and the door comprises sliders or trolleys (262, 362) adapted for moving on the rails.
4. Hatch and valve arrangement according to claim 3, characterised in that the guide rails (14, 16) are fixed on the housing (1).
5. Hatch and valve arrangement according to claim 1, characterised in that the doors (26, 36) comprise linking means (51, 61), onto which a disassembly arm (5, 6) can be permanently or temporarily fixed.
6. Hatch and valve arrangement according to claim 5, characterised in that the disassembly arm comprises a counterweight (52, 62) and attachment rings for handling each module by means of lifting equipment.

Images