LU87915A1 - Drilling machine and associated pinch bars for opening tap-holes in shaft furnaces - includes using machine fitted to carriage pinch bar on carriage to hydraulically advance drilling rod threaded through pinch bar etc. - Google Patents

Abstract

In the method a drilling rod (22) is introduced into the taphole (24) of a shaft furnace using a drilling machine fitted with a carriage (26) acting against the wall of the furnace (20). A pinch bar (46) mounted on this carriage (26) is able to be displaced longitudinally on the carriage (26) under the action of a hydraulic jack (42) mounted at the front of the carriage (26). After the drilling rod (22) is threaded through the pinch bar (46) the hydrualic jack (42) is operated to advance the drilling rod (22) over a length corresp. to the track of the hydraulic jack (42) whilst it is held by the pinch bar (46). The pinch bar (46) is then opened and is brought back to its start position so that the operation can be repeated until the drilling rod (22) is driven the desired depth into the taphole (24). The drilling rod can then be extd. in a similar manner. The drilling machine is also claimed along with a number of different types of bi-directional pinch bars that can be used to grip the drilling rod.

Description

METHOD FOR INSERTING A DRILLING ROD INTO THE CASTING HOLE OF A TANK OVEN. DRILLING MACHINE AND CLAMP PROVIDED FOR SUCH A MACHINE

The present invention relates to a method of introducing a piercing rod into the taphole of a shaft furnace before the complete hardening of a plugging mass previously injected into the taphole, method implemented in using a drilling machine comprising a working tool with a coupling means at the free end of the rod and movable along a mounting bearing on the wall of the oven, a clamp mounted on the mounting in axial alignment with the coupling device and movable longitudinally with respect to the mount under the action of a hydraulic cylinder mounted thereon. The invention also relates to a machine for introducing and extracting a drill rod into the taphole, as well as a clamp designed for such a machine.

The invention therefore relates to the now well-known method of the lost rod, according to which, after having closed the taphole with a plugging mass, a metal rod is pressed into it, before its complete hardening. . The opening of the tap hole therefore consists in extracting the rod from the hardened plugging mass at the desired time.

The machines used for the implementation of this process are the conventional drills, having, however, undergone appropriate adaptations and modifications. We must, in fact, preserve the possibility of being able to drill, from time to time, by conventional means, for example, to reform or move the taphole, or when the lost rod could not be used.

The working part of these machines must therefore include not only a drilling machine, which is admittedly only used occasionally, but also a mandrel with a coupling pliers and, above all, a powerful bi-directional pneumatic striker to deploy the force required to insert and remove the lost drill rod. Indeed, if the extraction of the rod is above all an operation of force, the introduction is an operation of force, skill and efficiency.

It is a force operation because, to introduce the rod, it is necessary to wait until the sealing mass has reached a certain degree of hardening to present the resistance and the support necessary for the rod.

It is also a skill operation, as the rod must be pushed in before the capping compound is completely hardened. However, since the sealing masses currently used are based on resins, their solidification is powerful and rapid and must be complied with. On average, the rod should be placed about 3 to 10 min. after the taphole is closed according to the quality of the plugging mass used.

Finally, the operation and its means must be effective, since the slightest breakdown or improper operation delays or slows down the operation of introducing the rod. Hence the risk that the rod remains blocked halfway due to too advanced hardening of the sealing mass. Such a very damaging situation can only be rectified by burning the part of the rod embedded in the hardened mass.

The bi-directional pneumatic striker seems to be the appropriate tool to meet these requirements and the fact that it has always been used until now for the introduction and the extraction of the rod seems to be the proof. Unfortunately, this is not the case, since such a striker is not without drawbacks. First, it imposes significant stresses and vibrations on the material, in particular on its mandrel and. its coupling clamp with the rod which, therefore, are subject to rapid wear and the need for frequent replacement. Secondly, it is extremely noisy and far exceeds current tolerances which, understandably, tend to be severe.

The patent FR-2619036 and the European patent 0128432 make it possible to partially remedy these drawbacks by proposing hydraulic, low-noise extraction means, from the drilling rod. The pneumatic striker, of course, if it no longer has to be bi-directional, is nevertheless still necessary for an efficient and rapid installation of the piercing rod.

Document EP-A2-0379018 proposes a clever method of extracting the rod in several phases by a back-and-forth movement of a clamp under the action of a hydraulic cylinder. Unfortunately, as in the two previous documents, the pneumatic striker is still necessary for the introduction of the piercing rod.

The various devices proposed by the aforementioned documents could all encourage the elimination of percussion during the introduction phase by subjecting the working tool, in substitution for the unidirectional striker, during introduction, to a means, for example hydraulic, more powerful for advancing the working tool along the carriage in the direction of the taphole to forcefully penetrate the drilling rod into the semi-hardened filling mass. Unfortunately, this attempt is not conceivable, because given the length of the rod, a more powerful push, without striker, would risk first of all causing the rod to buckle and then its final blocking in a partially pressed in position. the mass undergoing rapid hardening.

The object of the present invention is to provide a new method and new device which make it possible to dispense completely with the striker when using the lost rod, both during extraction and during the introduction of the rod. drilling.

To achieve this objective, the method proposed by the present invention is essentially characterized in that after having threaded the piercing rod through the pliers, or vice versa, and in coupling with the working tool, the actuator is actuated and the clamp to advance the rod using the clamp of a length corresponding to the stroke of the jack, in that the clamp is opened and brought back to the starting position and in that it is repeated these operations until the rod is pressed to the desired length in the taphole.

Since the reverse operation can be implemented for the extraction of the rod, one can do without the pneumatic striker completely to apply the method of the lost rod. Furthermore, since the clamp slides at the front end of the mount, the distance to the tap hole is relatively small so that there is no risk of the rod buckling during the 'strong introduction.

The invention also relates to a drilling machine which can be used for extracting and inserting a drilling rod into the tap hole of a shaft furnace, comprising a working tool with a coupling means at the end. free of the rod and movable along a carriage bearing on the wall of the oven, a clamp mounted on the carriage, in axial alignment on the coupling device and movable longitudinally with respect to the carriage, under the action of a hydraulic cylinder mounted thereon, characterized in that said clamp is a bi-directional clamp acting under the action of a pneumatic or hydraulic fluid, either in one direction or in the opposite direction.

The invention also relates to a bidirectional clamp designed for such a machine and comprising two pairs of jaws symmetrically arranged around an axial channel which can receive a piercing rod, and displaceable obliquely to said channel, the pair of jaws on the furnace side being oriented towards the front for the extraction of the rod and the pair of jaws on the opposite side being oriented towards the rear for the introduction of the rod.

Each pair of jaws can be activated by the hydraulic fluid of the jack via a pneumatic reversing valve so that one of the pairs of jaws is always deactivated while the other is activated and vice versa.

According to another embodiment, the bidirectional clamp has two inverted jaws movable parallel to each other and obliquely relative to the axial channel passing through their housing block.

The jaw of the jaw in service when the rod is removed is preferably on the furnace side and the jaw of the jaw in service when the rod is inserted is therefore preferably on the side opposite.

The axial channel preferably comprises two supports respectively diametrically opposite the jaws of the jaws to collaborate with them when they are in service.

Each jaw can also be actuated by the hydraulic fluid of the jack via a pneumatic reversing valve deactivating one of the jaws when the other is activated and vice versa.

The front part of the mounting of the drilling machine preferably comprises a support cooperating with the wall of the furnace both in pushing and in pulling in order to absorb the feedback.

Both the first embodiment of the clamp and the second include, preferably, a cylindrical block for housing the jaws provided over the entire length of a radial groove, the bottom of which is formed by the axial channel and opening towards the outside the block in a direction perpendicular to the plane of the jaws. This design allows the rod to be engaged laterally in the clamp. To facilitate this engagement, it is also preferable for the walls of this open groove to converge towards the inside of the block.

To facilitate cleaning and dust generation, it is further preferable that the jaws are positioned laterally with respect to the axial channel and that said groove is open downwards.

Other particularities and characteristics will emerge from the detailed description of several advantageous embodiments, presented below, by way of illustration, with reference to the appended drawings in which:

Figure 1 shows a general side schematic view of a drilling machine for the implementation of the method proposed by the present invention;

Figures 2 and 3 illustrate different phases of introduction of a drilling rod with the machine according to Figure 1;

Figure 4 shows the piercing rod in position after the introduction phase;

Figures 5 to 7 illustrate an axial section through a first embodiment of a bidirectional clamp and representing different operational phases during the introduction of a drilling rod;

FIGS. 8 and 9 illustrate two positions of the same bi-directional clamp when extracting a piercing rod;

Figure 10 illustrates an axial section of the second embodiment of a bi-directional clamp and Figures 11 and 12 show two advantageous embodiments of a clamp with open groove.

The machine represented in FIGS. 1 to 4 resembles, at first sight, the machine proposed by document EP-A2-0379018. It is a machine designed to open a tap hole of a shaft furnace 20 represented by a part of its wall, either by conventional drilling, or as shown in the figures, by extraction of a blocked rod 22 in the hardened plugging mass of the tap hole 24. The machine comprises a mount 26 carried at the end of a support arm 28, which can pivot around a console not shown between the operative position 20 according to the figures and a garage position away from the tap hole. A working tool 30 is mounted on a mobile carriage 32 slidably supported on the carriage 26. This working tool 30 is supplied with pneumatic or hydraulic fluid by means of articulated pipes, not shown, which can follow its movements.

At the front of the working tool 30 is a means 36 for coupling this tool 30 to the free end of the rod 22. This coupling means can be of the type described in French patents n ° 2520857 or 8212052.

An intermediate support 38 is also slidably mounted on the carriage 26 and serves as an intermediate support for the rod 22.

The reference 34 designates a support designed, for example, in the form of male and female elements respectively provided on the wall of the oven and the front end of the mount 26, or vice versa to absorb the reactions and counter-reactions during the introduction and extraction of the rod 24. A lock 40 makes it possible to secure this support to the wall of the furnace in the direction of a pull. When the machine is vertically movable, the support may consist of a hook, which makes it possible to eliminate the latch 40.

At the front of the carriage 26 is, moreover, a hydraulic cylinder 42 whose rod 44 is movable in the longitudinal direction of the carriage 26. The end of the piston rod 44 is connected to a clamp 46 able to slide between the two rails forming the mount 26 and capable of gripping and gripping the piercing rod 22.

The machine as described so far allows the implementation of the extraction process of the rod 22 by reciprocating movements as described in the aforementioned document EP-A2-0379018. However, unlike this document, according to which the clamp is active only in one direction, in this case the direction of extraction to the right in the figure, the clamp 46 according to the present application is actively used in both directions , that is to say not only for the extraction of the rod, but also for its introduction and its positioning in the plugging mass of the tap hole 24.

To this end, a piercing rod 22 is put in place according to FIG. 1 on the machine, preferably already in the garage position, or before occupying the working position of the machine shown in FIG. 1. rod 22 is therefore engaged axially through the clamp 46 bearing on the support 38 and in engagement with the clamp 36 of the working tool.

When the rod 22 extends to the front end of the mount, it is preferable, so as not to have to thread it axially through the clamp, to use an open clamp as described below, in order to be able to engage the rod laterally in the clamp. On the other hand, if the rod 22 is shorter, or the carriage longer, it is possible to completely advance the clamp 46, to engage the rod 22 in the mandrel 36, to place it, in cantilever , on the support 38 and engage the clamp 46 axially, moving back, around the rod, the clamp can, therefore, be a closed clamp.

To introduce the rod 22 into the taphole, the clamp 46 is activated by its pneumatic circuit to grip the rod 22, and the jack 42 is actuated to release its rod and move the clamp 46 to the left into the position of the Figure 2. The clamp 46 is then opened and the rod 44 of the jack 42 is retracted to move the open clamp back along the rod 22 now immobilized by inertia or hooking in the inlet of the semi-hardened plugging mass of the hole casting 24.

When the clamp 46 has returned to the position of FIG. 1, the back-and-forth movement is repeated as many times as necessary to push the rod into the final position according to FIG. 3.

During the introduction of the rod, it is preferable to secure the carriage 26 with the wall of the furnace 20. For this purpose, it suffices to manually engage or by an automatic system the lock 40 to ensure the male connection and female at the support 40. This locking makes it possible to absorb the counter-reaction forces to the right when the rod 22 is pressed under the action of the jack 42. At the end of the introduction of the rod, the latch 40 is raised to release the support 34 from the wall of the oven and to be able to withdraw the machine towards the garage position and abandon the rod 22 in the position according to FIG. 4.

To open the taphole, the machine is returned to its working position and the rod 22 is extracted from the position in FIG. 4 according to the known method recommended by document EP-A2-0379018.

In order to be able to implement this advantageous method of introducing and extracting a piercing rod, without the obligation of having to use the pneumatic striker, a two-way pliers must necessarily be able to pull the rod in one direction and in the opposite direction and means for actuating the clamp appropriately without the two functions interfering with each other.

The next figures illustrate advantageous embodiments of such a bi-directional clamp. The first embodiment illustrated in FIG. 5 is a pair of pliers 46 comprising a first pair of jaws 50 and a second pair of jaws 52 each contained in a housing block 54a, respectively 54b welded or otherwise joined together. one to the other to form the housing 54 of the clamp. Each of the four jaws is constituted, in a manner known per se, of a rod 56 provided at the inner end with a jaw 58 and at the outer end with a piston 60. The axes of the four jaws are all inclined at the same acute angle with respect to a channel 62 passing axially through their housing block and intended to receive the rod 22. This inclination contributes to the fact that, under the effect of traction, the jaws automatically bite into the rod 22. The pistons 60 of each jaw are also biased, on one side, by a spring 64 in the direction of opening and release of the contact of the jaw 58 with the rod 22 and, on the other side, by a pneumatic circuit in the direction of closure and engagement of the jaw 58 with the rod 22 against the action of the spring 64. The pneumatic control circuit of the jaws can be actuated by the hydraulic circuit of the jack 42 by means of a pneumatic reversing valve not shown smelled.

The individual jaws of each pair 50, 52 are therefore arranged symmetrically with respect to the axis of the channel 62, while two pairs are positioned, one with respect to the other, symmetrically with respect to a vertical plane forming , in plan, a diamond configuration. This allows, among other things, to turn the pliers so that the rod extraction jaws become the introduction jaws and vice versa.

The housing blocks 54a, 54b are each provided on their free front side with a plate 66a, 66b provided with a divergent opening around the channel 62 to facilitate penetration of the rod 22.

In the configuration shown, the jaws 52 are activated according to FIG. 5 to push the rod into the taphole to the left in the figures. At the end of the stroke, the clamp 46 and the jaws 52 are opened by releasing the pneumatic pressure on their piston 60 and under the action of their spring 64 which allows the clamp to be brought back under the action of the jack towards the straight in the position of Figure 6, the rod 22 remaining stationary. The jaws 52 are then actuated again (see FIG. 7) to drive the rod more than the length corresponding to the stroke of the clamp 46.

The pneumatic control circuit must be designed so that the jaws 50 remain inactive during the repetition of the operations according to FIGS. 5 to 7 to avoid canceling the advancement of the rod 22 by a retreat under the action of the jaws 50.

The roles are reversed during the extraction of the rod illustrated in FIGS. 8 and 9. The jaws 50 are now activated to grip the rod 22 and drive it to the right in the position of FIG. 9. The jaws 50 are then open to move the clamp to the left and release the rod of an additional length corresponding to the stroke of the clamp. During this extraction, it is the jaws 52 which remain inactive.

Instead of the configuration shown in Figures 5 to 9, the jaws could also be arranged in "X", the introduction jaws then being placed on the side of the oven. However, the configuration illustrated in the figures deserves preference, because when the introduction jaws are arranged behind the extraction jaws, it is always certain not to push the rod beyond the limit where it could no longer be grasped with the extraction jaws.

Figure 10 shows an embodiment of a more compact clamp comprising only an extraction jaw 72 and an introduction jaw 74 of a rod 22. The two jaws are arranged in opposite directions, in parallel one to the other, at the same angle of inclination relative to the channel 76 which passes through their housing block 78.

The clamp 70 operates in the same way as the clamp 46 of the embodiment described above. However, to compensate for the absence of a second jaw, the axial channel 76 has, on the opposite side of each jaw 72, 74 a support 72a, 74a intended to cooperate with the jaw activated to wedge the rod 22. These supports 72a, 74a can be flat as in the figure or have edges to improve the grip of the rod.

Figure 11 shows an axial view of a clamp 70 according to Figure 10. The clamp 70 is fixed, for example screwed, on a shoe 80 actuated by the rod 44 of the piston 42 (Figure 1) and intended to slide between two beams 26a, 26b forming the lookout 26.

According to an advantageous embodiment, the axial channel 76 forms the bottom of an open longitudinal radial groove 86. This groove 86 allows the lateral engagement of the rod 22 in the clamp 70 and further facilitates the internal cleaning of the clamp. The walls of the groove 86 preferably move away from the inside towards the outside, which further facilitates the engagement of the rod 22.

In the embodiment of Figure 11 the jaws are provided laterally relative to the channel 76 while the groove 86 opens downward.

In the variant according to Figure 12 the jaws are provided above and below the channel 76 which opens by a groove 88 to the side.

FIG. 11 has the advantage of greater ease of releasing dirt and dust, while FIG. 12 has the advantage of greater ease of engagement of the rod 22.

It is obvious that the variants of FIGS. 11 and 12 are also suitable for the twin pliers of FIGS. 5 to 9.

Claims (13)

1. Method for introducing a piercing rod into the tap hole of a shaft furnace before complete hardening of a plugging mass previously injected into the tap hole, process implemented using a drilling machine comprising a working tool (30) with a coupling means (36) at the free end of the rod (22) and movable along a mount (26) resting on the wall of the oven (20), a clamp (46) mounted on the carriage (26) in axial alignment on the coupling device (36) and movable longitudinally relative to the carriage (26) under the action of a hydraulic cylinder (42) mounted on the carriage, characterized in that after having threaded the rod (22) through the clamp (46) or vice versa and in coupling with the working tool (30), the actuator ( 42) and the clamp (46) for advancing the rod using the clamp (46) by a length corresponding to the stroke of the jack (42), in that the clamp is opened (4 6) and it is brought back to the starting position and in that these operations are repeated until the rod is pressed to the desired length in the taphole. 2. Machine for drilling a tap hole of a shaft furnace comprising a working tool (30) with a means (36) for coupling to the free end of the rod (22) and movable along d 'a carriage (26) resting on the wall of the oven (20), a clamp (46) mounted on the carriage (26) in axial alignment with the coupling device (36) and movable longitudinally relative to the carriage (26) under the action of a hydraulic cylinder (42) mounted thereon, characterized in that the clamp (46) is a bidirectional clamp acting under the action of a pneumatic or hydraulic fluid, either in one direction, either in the opposite direction. 3. Machine according to claim 2, characterized in that the front part of the carriage (26) comprises a support (34) cooperating with the wall of the oven (20), both in pushing and in traction. 4. Machine according to claim 3, characterized in that the support can be secured to the oven using a lock (40) actuated manually. 5. Bi-directional clamp for a machine according to claim 2, characterized in that it comprises two pairs of jaws (50), (52) arranged symmetrically around an axial channel (68) and displaceable obliquely to said channel (68), the pair of jaws on the furnace side being oriented towards the front for the extraction of the rod and the pair of jaws (52) on the opposite side serving for the introduction of the rod (22). 6. Gripper according to claim 5, characterized in that each pair of jaws (50), (52) is actuated by the hydraulic fluid of the jack (42), via a pneumatic reversing valve so that one of the pairs (50), (52) is always deactivated while the other is activated and vice versa. 7. Bi-directional clamp for a machine according to claim 2, characterized in that the clamp has two jaws (72), (74) reversed, movable parallel to each other and obliquely to the axial channel (76) passing through their housing block ( 78), 8. Pliers according to claim 7, characterized in that the jaw of the jaw in service during the extraction of the rod (22) is on the furnace side and in that the jaw of the jaw in service during the introduction of the rod (22) is on the opposite side. 9. Pliers according to claim 7, characterized in that the axial channel (76) comprises two supports (72a), (74a) respectively diametrically opposite the jaws of the jaws (72), (74). 10. Clamp according to claim 7, characterized in that each jaw (72), (74) is actuated by the hydraulic fluid of the jack (42) by means of a means deactivating one of the jaws when the other is activated and vice versa. 11. Pliers according to any one of claims 5 or 7, characterized in that it comprises a cylindrical block (78) for housing the jaws, provided over the entire length of a radial groove (86) whose bottom is formed by the axial channel (76) and opening towards the outside of the block (78) in a direction perpendicular to the jaw of the jaws (72), (74). 12. Pliers according to claim 11, characterized in that the walls of the groove (86) converge towards the inside of the block (78). 13. Pliers according to claim 11, characterized in that the jaws (72), (74) are positioned laterally relative to the axial channel (76) and in that said groove (86) is open downwards.