EP3167083B1 - Device for immobilising the chute on the ends of trunnions in an apparatus for loading a shaft furnace - Google Patents

Description

Technical area

The present invention relates to the attachment of a distribution chute of a charging installation of a shaft furnace, such as a blast furnace, on the journals supporting the chute and ensuring its pivoting. It relates more particularly to the locking system of the chute on the ends of the trunnions.

State of the art

A charging installation for a shaft furnace typically comprises a fixed feed channel arranged vertically in the center of the top, centered on the vertical axis of the furnace, and a distribution chute for distributing in the furnace the charged materials arriving by said furnace. channel. To enable the dispensed material to be dispensed adequately, the dispensing chute is rotatable along said vertical and pivoting axis along a horizontal axis. To this end, the chute is typically pivotally mounted along said horizontal axis in a ferrule mounted coaxially around said feed channel and rotatable along the vertical axis. The chute is pivotally mounted in the shell by means of generally cylindrical pins of horizontal axis, on which the chute is secured and which are rotatably mounted along said horizontal axis in integral bearings of the ferrule. The rotation of the ferrule and the pivoting of the chute are generally provided by gear means located in an annular chamber surrounding the ferrule.

The chute is fixed on both sides on the radially inner ends, directed towards the vertical axis of the furnace, of the journals, which are pivotally driven by means of the gear drive means located in said chamber surrounding the ferrule. These drive means can act directly on the journals by meshing, or by means of arms or levers.

To ensure proper operation of the chute, it must be firmly and rigidly connected to the trunnions. But in particular to allow a easy replacement of the chute, it is supported and removably attached to the trunnions.

To ensure these two needs of rigid connection but nevertheless removable, it is known to use a connection such as that illustrated on the figure 1 , where the trough 1 comprises, towards its upper part, fastening lugs 11 of a shape adapted to engage in housings 21 of corresponding shape formed on the ends of the trunnions 2. It will be noted that the shapes of the lugs and the housings are particularly drawn so as to allow to engage the tabs in the housing, then, by a relative pivoting, apply the tabs in the bottom of housing. Maintaining this position is provided by a locking pin 3 which is removable to allow to release the legs of the chute out of the housing of the trunnions, but which must also ensure that the assembly of the legs on the trunnions is safe and without play .

Typically, the locking pins comprise a cylindrical body slidably mounted and rotating in a bore formed in the journal and having an axis parallel to that of the journal, an eccentric stud 31 formed at the end of the body located towards the chute, and means for rotational control and rotational locking, located at the opposite end of the pin body, accessible at the outer end end of the journal which is located in the annular chamber surrounding the ferrule. When placing the chute, after the legs thereof are positioned in the housing of the trunnions, the locking pins are pushed axially in the holes of the trunnions until the eccentric pins are inserted into holes made to this effect in the legs of the chute. By pivoting the pins, and thanks to the eccentric nipples, they act on the legs of the chute, pushing on the walls of the leg holes, to push them in the bottom of their homes, and ensure the assembly without play of the chute on the trunnions. To prevent the pin can disengage by sliding axially, and also to ensure that the pin does not rotate later during operation of the oven, which could cause a separation of the chute, locking means are provided at the level of end of the pin opposite the pin, to block any displacement of the pin both axially and rotationally. A particular problem is that locking in It must be possible to rotate the pin in different angular positions thereof, because this angular position is determined by the cooperation of the eccentric pin with the hole in the leg of the chute and, because of the dimensional dispersions between the housings of the chute. ends of the trunnions, the legs of the chute, the pins and the holes in which they engage, or also deformations or wear of these elements, said angular position of the pin, adapted to ensure the correct locking of the chute, is variable from one assembly to another, and / or must be adjustable to ensure maintenance without play of the assembly.

To answer this problem, a known embodiment of these locking means consists of an arm secured to the end of the pin, which has at its end a screw and an adjusting nut and locking, which allows to block the said arm on the front end of the journal in different positions, thereby immobilizing the pin in the desired position. In another embodiment, the arm is replaced by a flat tab that can be clamped to the front end of the journal in a plurality of positions.

A disadvantage of these locking pin locking systems is that they occupy a large part of the front end surface of the pin, while it is also occupied by the connections of cooling ducts formed in the pins to cool these, as well as possibly the chute. Typically, these connections are more cumbersome because they include rotating joints, necessary to connect the pivoting pins to the fixed ducts for supplying cooling water. It follows that it is necessary to disassemble these rotating joints to have access to the pin locking means, when it is necessary to act on them, especially during the replacements of the chute. Accordingly, particularly when using a pressurized cooling system, it is then necessary to purge the circuit prior to disassembly and then fill it again. Errors can be made then and during the restart of the cooling. In addition, the cooling of the trunnions is stopped during the entire operation of replacing the chute, while the trunnions remain exposed to the intense heat prevailing in the furnace.

The document WO 2013/107078 A1 discloses a material distribution chute of a charging installation of a shaft furnace. The chute is pivotally mounted along a horizontal axis by means of rotating journals in bearings of a supporting ferrule having a vertical axis of rotation. The chute is connected to the trunnions by upper end tabs of the chute which engage in housing arranged on internal ends of the trunnions. The legs are locked by pins housed in the pins and axis parallel to the axis of the trunnions. The installation solution includes means for locking the chute on the ends of trunnions. However, it is not very effective. Moreover, the disassembly of the chute is difficult.

Object of the invention

An object of the present invention is to solve the aforementioned problems. It aims in particular to allow the replacement of the chute without requiring disassembly of rotary joints. It also aims to keep the cooling circuit in use during chute change operations. It is particularly intended to reduce the size of the locking means locking pins of the chute, while ensuring, however, both the reliability of this blockage and the possibility of ensuring it in the various angular positions where it can It is necessary to place the pins in order to ensure that the legs of the chute do not play on the trunnions.

With these objectives in view, the invention relates to a device for blocking the chute on the ends of the trunnions, in a charging installation of a shaft furnace as indicated above, having a material distribution chute mounted pivoting along a horizontal axis by means of rotating journals in fixed bearings of a supporting ferrule having a vertical axis of rotation, the chute being connected to the journals by upper end tabs of the chute which engage in housings arranged on inner ends of the pins and which are blocked by pins housed in the pins and axis parallel to the axis of the pins, each pin having at its inner end oriented towards the vertical axis an eccentric pin engaging with a leg of the chute to hold the tab locked at the bottom of its housing, and locking means to lock the pin e in rotation.

According to the invention, this system is characterized in that each pin comprises, at its outer end opposite the pin, means for adjusting in rotation and clamping, to be able to press with sufficient effort the pin on the leg of the chute by a rotation of the pin, and the locking means comprise an indexing plate rotatably connected to the end of the pin, the plate further comprising teeth arranged to cooperate with the corresponding teeth of a latch fastened to the trunnion. such that said latch can immobilize the pin in rotation in a plurality of circumferential positions of said pin.

General description of the invention

As will be better understood later, the device according to the invention allows easy access to the pin by simply removing the indexing plate, which then allows to rotate the pin to unlock the legs of the chute, then pull it axially to allow the legs of the chute out of their homes in the trunnions, and thus allow the removal of the chute and its replacement. It suffices for this to be able to access the fixing means of the indexing plate on the external end of the trunnion, which can be done without interfering with the other elements fixed on said front end, such as in particular rotating joints of the cooling circuit. When reassembling the chute, the pin is put back in place, turned and tightened to ensure the pressure of the eccentric pin on the leg of the chute, then locked in position by engagement of the teeth of the index plate with those of the lock, as will be specified later.

To allow said locking by engagement of the teeth, regardless of the angular position of the pin, the indexing plate is rotatably connected to the pin by means of rotational connection arranged to ensure the rotational connection at different relative angular positions. . After locking the legs of the chute obtained following the rotation of the pin, simply place the indexing plate on the pin in a position for engagement of its teeth with those of the lock.

Preferably, the rotational connection means comprise a polygonal shape made on the pin cooperating with a cutout of suitable shape made in the index plate. Also preferably, the polygonal shape of the pin is hexagonal and the cutting of the index plate is in the form of a double hexagon. This arrangement therefore makes it possible to adjust the relative angular position between the pin and the indexing plate with a pitch limited to 1/12 turn or 30 degrees of angle.

According to a particular arrangement, the polygonal shape of the pin extends towards the outer end of the pin to serve also as means of adjustment in rotation and clamping, for example by a polygonal key of the current type.

According to another advantageous particular arrangement, the indexing plate is fixed on an external end of the trunnion, and serves as an axial abutment of the pin, thus preventing any risk of removal of the pin by axial sliding in its bore made in the trunnion. .

Advantageously, the indexing plate is fixed on the trunnion by bolts passing through the slots of the indexing plate, said slots being in the shape of a circular arc centered on the axis of rotation of the pin. These lights allow the attachment of the indexing plate on the trunnion in a plurality of angular positions, limited only by the length of the lights, and thus allows to accurately position and maintain the index plate, and therefore the pin, in the angular position adapted to ensure the clamping of the leg of the chute in its housing.

The lock preferably comprises a plate having teeth engaging with the teeth of the indexing plate, the teeth of the indexing plate and the lock plate being arranged according to arcs of circles centered on the axis of rotation. of the pin, which allows the locking of the indexing plate regardless of the relative angular positions of the indexing plate and the lock.

The lock plate is fixed on the outer end end of the pin by bolts passing through the slots of the plate, said slots being circular arc-shaped centered on the axis of rotation of the pin. In addition, lateral stop means are provided to limit the stroke of the wafer in the circumferential direction. These lateral abutment means preferably comprise a side wall of a housing formed in the external end of the trunnion and in which the lock plate is fixed, said side wall of the housing acting as an abutment for one end of the wafer. Thus, a reliable locking of the pin in the required position is obtained to ensure the locking of the legs of the chute by the eccentric pin, the rotational connection of the pin with the indexing plate, then the engagement of the teeth of the latter with the lock, then locking the lock by stop in its housing.

Preferably again, the ends of the wafer are offset by half a pitch of teeth with respect to the toothing of the wafer. This provision allows, by a reversal of the wafer on itself, to be able to lock the pin in rotation with an even finer adjustment of its angular positioning, reduced to an angle value corresponding to the angular value of a half step of the locking teeth.

According to a complementary arrangement, the indexing plate is housed in a housing formed on the front end of the journal, the housing comprising side walls which constitute pivoting abutments of the indexing plate, with a sufficient angular clearance to allow to place the indexing plate in its housing whatever the angular position of the pin. Typically when the connection between the pin and the indexing plate is provided by a hexagonal shape of the pin and a double hexagon shape of the cutting of the indexing plate in which engages said hexagonal shape of the pin, the angular clearance between the index plate and the side walls of its housing is 30 degrees. This means that the indexing plate can be placed in its housing in a plurality of angular positions over a 30 degree arc.

These various arrangements make it possible to ensure triple safety against the risk of undesirable pivoting of the pin which could lead to separation of the chute on its trunnions: in normal situation, the lock plate ensures the locking in rotation of the plate indexing and pin; if the wafer was to be lost, the indexing plate still ensures the maintenance of the pin in rotation, because it is tightened by its fixing bolts; and if these bolts were to be loosened, the pin could rotate a maximum of one twelfth of a turn, held by the stop of the indexing plate in its housing. In the latter case, certainly the chute could no longer be properly maintained by clamping its legs in their housing of the front ends of the trunnions, but the legs could not however be released completely from their homes, and the chute would not be lost by his fall in the blast furnace.

Brief description of the drawings

• La figure 1, déjà commentée, est une vue de la liaison entre la goulotte et les tourillons de support ;
• La figure 2 est une vue générale du système de support et d'entraînement en pivotement de la goulotte, vu du côté de l'extrémité frontale externe d'un tourillon ;
• La figure 3 est une vue en coupe axiale du tourillon, dans le plan radial contenant la goupille ;
• La figure 4 est une vue en perspective de la goupille équipée de la plaque d'indexation et avec la plaquette de verrouillage ;
• La figure 5 est une vue en coupe transversale selon la ligne V-V de la figure 3 ;
• Les figures 6 et 7 montrent deux positions alternatives de la plaquette de verrouillage engagée avec les dentures de la plaque d'indexation.

Other features and characteristics of the invention will emerge from the detailed description of an advantageous embodiment presented below, by way of illustration, with reference to the appended drawings, in which:

• The figure 1 , already commented, is a view of the connection between the chute and support pins;
• The figure 2 is a general view of the support and pivoting system of the chute, seen from the side of the outer end of a trunnion;
• The figure 3 is an axial sectional view of the pin in the radial plane containing the pin;
• The figure 4 is a perspective view of the pin equipped with the indexing plate and with the locking plate;
• The figure 5 is a cross-sectional view along line VV of the figure 3 ;
• The Figures 6 and 7 show two alternative positions of the locking plate engaged with the teeth of the indexing plate.

Description of a preferred execution

The support system and pivoting drive of the trough shown figure 2 comprises, on each side of the chute, a bearing 22 in which the pin 2 is rotatably mounted on a horizontal axis A1, and pivoted by a mechanism comprising a gear case 23, an output shaft carries a gear 24 meshing with a toothed sector 25 of a control arm 26 connected in rotation with the journal.

On the outer end 29 of the pin 2, that is to say the end face of the pin opposite the end having the housing 21 for the lugs 11 of the chute 1, rotating joints 28 are connected to connect ducts for internal cooling of the trunnions. We also see, in eccentric position with respect to the axis A1, the end 32, shaped in hexagon, of the pin 3 opposite to the eccentric pin 31 which cooperates with the tab 11 of the chute to block it in its housing 21, as indicated at the beginning of this brief in relation to the figure 1 , and the means 4 for locking in rotation of the pin 3 on the trunnion, which particularly comprise an indexing plate 41 and a locking plate 42.

On the figure 3 showing a journal in axial section, we see the journal 2 rotatably mounted in the bearing 22 along the horizontal axis A1, and the housing 21 intended to receive the tab 11 of the chute, and an axial cooling channel 27 on which is connected the rotary joint 28.

The pin 3 is rotatably and slidably mounted in a bore of axis A2 of the journal parallel and eccentric by contribution to the axis A1. Its inner end, located towards the chute, comprises the eccentric pin 31 which, in the blocking position of the chute, protrudes axially in the housing 21 to engage in the hole provided for this purpose in the lug 11 of the chute. At its outer end 32, opposite to the pin 31, the pin is shaped according to a hexagon 321 which is engaged with a hole in the form of a double hexagon 411 made in the indexing plate 41, and protrudes from this plate so as to be able to place a wrench to turn the pin 3 along its axis A2 and thus rotate the eccentric pin and block the leg of the chute in its housing, as indicated above. The indexing plate 41 is housed in a housing 5 formed for this purpose in the outer end of the trunnion, and being fixed to the bottom of this housing, axially blocks the pin to prevent the eccentric pin from emerging from the hole the leg of the chute by axial sliding of the pin.

As can be seen from the figures 4 and 5 , the indexing plate 41 comprises two arms 412, 413 extending in substantially diametrically opposite directions, in which oblong slots 414 are formed in circular arcs centered on the axis A2 of the pin. Fastening bolts 415, passing through these slots and screwed into the trunnion, make it possible to tighten the indexing plate 41 on a front wall 51 constituting the bottom of the housing 5, thereby immobilizing the indexing plate, and thus the pin, in rotation. .

One of the arms 413 carries at its end a right-angle toothing 416 in the form of an arc of a circle, centered on the axis A2, which engages with a corresponding toothing 421 formed on the locking plate 42. The locking plate 42 comprises an oblong slot 422 in which passes a bolt 423 for fixing the plate in the housing 5 of the pin.

The locking plate 42 is housed in a portion 52 of the housing 5 having a side wall 53 arranged to abut one of the ends 424, 425 of the wafer 42. The housing 5 also has two side walls 54, 55 confronting the faces side of arms 412 and 413, but arranged so that there remains overall between said arms and said side walls games j1, j2 allowing an overall angular clearance j1 + j2 of the index plate equal to, or slightly greater than, 30 °, necessary to allow to place the plate d indexing 41 in both the housing 5 and the hexagonal end 32 of the pin 2, regardless of the angular position of said pin.

As we see on the Figures 6 and 7 , the ends 424, 425 of the fixing plate are offset by half a step with respect to the toothing, so that, by a reversal of the plate, it is possible to ensure the best, and whatever the angular position of the pin and the indexing plate, both the engagement of the teeth of the indexing plate and the locking plate, and the stop of the locking plate against the side wall 53 of its housing. Thus, if, because of the angular position where the pin is located after having locked the chute by the rotation of said pin, the engagement of the teeth, while the locking plate is placed in a first direction, would lead to a clearance between the end 424 of the wafer and the side wall 53 as shown figure 6 it is possible to eliminate or at least reduce this game by turning the wafer so that it is then the other end 425 which is in abutment, without play, against the side wall 53, as shown figure 7 .

To set up a chute 1, the lugs 11 thereof are placed in the housing 21 of the support pins 2. Then, on each side, the pin 3 is thrust axially so as to make the eccentric stud 31 penetrate into the hole of the lug 11. By means of a key engaged on the end 32 of the hinge pin, one makes turn the pin until the pin 31 blocks the tab 11 in the housing 21. In this position, the indexing plate 41 is adjusted on the hexagon 321 of the end of the pin so that said plate is inserted into the housing 5 of the front end of the journal with a minimum clearance, and the bolts 415 are tightened so as to clamp the indexing plate 41 against the bottom 51 of its housing, thus immobilizing the pin axially and in rotation . The locking plate 42 is then positioned in the direction ensuring a zero or minimum clearance between the end 424 or 425 of the wafer and the wall 53 of its housing, and the bolt 423 holding the wafer is tight.

Thanks to the different relative angular positions between the pin and the indexing plate, which can be obtained by the engagement of the double hexagonal shape of the indexing plate with the hexagonal form 321 of the end of the pin, and thanks to the teeth 416, 421 which can engage respectively with an angular pitch corresponding to the pitch of the toothing, and thanks to the possibility of reversal of the locking plate, it can finally ensure a reliable locking and virtually without play of the pin whatever its angular position. In addition, as already indicated, a triple security exists to prevent the chute from falling, even in the case where the locking plate would disappear and that the bolts of the indexing plate would come to loosen.

The invention is not limited to the embodiment described above by way of example. Instead of a hexagonal shape of the end of the pin to allow its rotation by a key, one could use any other form adapted to the clamping tool used. The hexagonal and double-hexagonal shapes of the connection between the indexing plate and the pin could also be replaced by other polygonal shapes of the same function, for example a square on the pin and a double square in the indexing plate , games j1 and j2 being adapted accordingly.

Claims (15)

1. A device for immobilising the chute on the ends of the trunnions, in a charging installation for a shaft furnace comprising a material distribution chute (1) mounted to pivot about a horizontal axis (A1) by means of trunnions (2) rotating in bearings (22) of a supporting shell having a vertical axis of rotation, the chute (1) being connected to the trunnions (2) by lugs (11) at the upper end of the chute which engage in receptacles (21) formed in the inner ends of the trunnions and which are immobilised therein by pins (3) accommodated in the trunnions and having an axis (A2) parallel to the axis of the trunnions, each pin (3) comprising at its inner end oriented towards the vertical axis an eccentric nipple (31) engaging with a lug of the chute to hold the lug immobilised at the bottom of its receptacle, and locking means for rotationally locking the pin,
   characterised in that each pin (3) comprises, at the outer, opposite end thereof from the nipple, means (32) for rotational adjustment and tightening, so as to be able to press the nipple onto the lug of the chute with sufficient force by rotation of the pin, and the locking means (4) comprise an indexing plate (41) connected for rotation to the end of the pin, the indexing plate further comprising teeth (416) arranged to cooperate with corresponding teeth (421) of a lock (42) secured to the trunnion (2), in such a way that said lock can rotationally immobilise the pin in a plurality of circumferential positions of said pin.
2. A device according to claim 1, wherein the indexing plate (41) is connected for rotation to the pin by rotational connecting means (321, 411) arranged to ensure rotational connection in various relative angular positions.
3. A device according to claim 2, wherein the rotational connecting means have a polygonal shape (321) formed on the pin which cooperates with a cutout (411) of suitable shape formed in the indexing plate (41).
4. A device according to claim 3, wherein the polygonal shape (321) of the pin is continued towards the outer end of the pin so as also to serve as means for rotational adjustment and tightening.
5. A device according to claim 3, wherein the polygonal shape of the pin is hexagonal (321) and the cutout in the indexing plate takes the form of a double hexagon (411).
6. A device according to claim 1, wherein the indexing plate (41) is fixed to an outer, front end of the trunnion and serves as an axial stop for the pin (3).
7. A device according to claim 1 or claim 6, wherein the indexing plate (41) is fixed to the trunnion (2) by bolts (415) passing through slots (414) in the indexing plate, said slots taking the form of an arc of a circle centred on the axis of rotation (A2) of the pin.
8. A device according to claim 1, wherein the lock comprises a plate (42) comprising the teeth (421) which engage with the teeth (416) of the indexing plate (41).
9. A device according to claim 8, wherein the teeth (416; 421) of the indexing plate (41) and of the lock plate (42) are arranged along arcs of circles centred on the axis of rotation (A2) of the pin.
10. A device according to claim 8, wherein the lock plate (42) is fixed to the outer, front end of the trunnion by bolts (423) passing through slots (422) in the lock plate, said slots taking the form of arcs of circles centred on the axis of rotation of the pin.
11. A device according to any one of claims 8 to 10, comprising lateral stop means (53) for limiting the travel of the lock plate (42) in the circumferential direction.
12. A device according to claim 11, wherein the lateral stop means comprise a side wall (53) of a receptacle (52) formed in the outer, front end of the trunnion (2) and in which the lock plate (42) is fixed, said side wall (53) of the receptacle serving as a stop for one end (424, 425) of the lock plate.
13. A device according to claim 12, wherein the ends (424, 425) of the lock plate are offset by half a tooth pitch relative to the teeth (421) of the lock plate.
14. A device according to claim 8, wherein the indexing plate (41) is accommodated in a receptacle (5) formed at the front end of the trunnion, the receptacle comprising side walls (54, 55) which constitute stops for the pivoting of the indexing plate, with angular play for placement of the indexing plate in its receptacle.
15. A device according to claim 14, wherein the angular play (j1, j2) between the indexing plate and the side walls (54, 55) of the receptacle thereof is 30 degrees.

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