EP1381480B1 - Method and device for semi-automatic on-site production of metal tanks - Google Patents

Abstract

The invention concerns a method whereby a steel strip (41) derived from a roll is gradually straightened out, cambered and engaged on rollers (13) supported on cylinders (12), until, after the corresponding perimeter is obtained, the ends are separated and welded together, then in lifting with the actuators (12) said first hoop to a height sufficient for production, then gradually assembling by welding a second hoop by the above process. All those operations are managed by a programmable automaton.

Description

The invention relates to a method and a device for semi-automatic on-site production of tanks high capacity cylindrical metal.

Economic problems for the production of large diameter steel tanks, the fact that it is excluded, for reasons space, to realize them elsewhere than on sites, builders are forced to open a specific site on the premises of implementation, sometimes shifting a team large number of specialized workers (boilermakers industrialists, welders, etc.) who do not have the well their task, that of basic material, facilitating forming, flame cutting and welding of plates sheet whose dimensions must be limited, to facilitate handling and assembly. It results of that a waste of time resulting in prices high cost and problems with respect the deadline imposed by the client, relatively to the schedule previously established with representatives of other trades.

We already know a method and a device for producing cylindrical tanks and ferrules from sheet metal, such as those described in European Patent No. 0136581 with which the ferrules are obtained by plating strips of sheet metal against the edge of a turntable, of appropriate diameter, on which the said strips are introduced progressively as the reel unwinds and the sheet metal straightens.

However, this method and this device cannot be used only for the production of low ferrules thickness, taking into account the flexibility of the sheet required by this mode of forming.

a) Réalisation d'une première virole.

b) Mise en place et solidarisation d'un toit sur la première virole.

c) Levage de l'ensemble réalisé à l'opération précédente à une hauteur correspondant à la largeur de la bande de tôle.

d) Réalisation d'une seconde virole sous le premier.

e) Solidarisation progressive de la virole réalisée à l'opération (a) à celle réalisée à l'opération précédente (d).

f) Répétition des opérations (c) (d) et (e) autant de fois que nécessaire pour obtenir la hauteur de cuve désirée.

g) Mise en place de l'ensemble, réalisé en suivant les opérations ci-dessus sur un fond de diamètre correspondant et solidarisation de celui-ci à la dernière virole.

There is also known a method and a device for semi-automatic production of reservoirs and ferrules corresponding to the preamble of claim 1 (European Patent No. 0727264 ). The method consists in carrying out, in order, the following operations:

a) Creation of a first ferrule.

b) Installation and securing of a roof on the first shell.

c) Lifting of the assembly carried out in the previous operation to a height corresponding to the width of the sheet metal strip.

d) Creation of a second ferrule under the first.

e) Progressive joining of the shell made in operation (a) to that made in the previous operation (d).

f) Repeat operations (c) (d) and (e) as many times as necessary to obtain the desired tank height.

g) Installation of the assembly, carried out by following the above operations on a base of corresponding diameter and securing it to the last ferrule.

The ferrules are produced by bending, bending, as the training and progress of the sheet metal coil. When performing a ferrule, directly under the previous one, the strip of sheet is progressively attached to the coil previous, that it drives in rotation, this solidarity being preceded by a support while as progressive from this previous ferrule on the edge of the sheet metal strip while scrolling until complete completion of this next shell. The control of the bending of the sheet metal strip, according to the required radius, is permanently assured, as and measurement of the drive and the scrolling thereof.

The device for applying the above method mentioned, is mainly characterized by the use of training and arching means a strip of sheet metal from a roll and rollers associated with distributed lifting cylinders regularly on a circumference to constitute a roundabout, of diameter corresponding to that of the ferrules to be made, intended to gradually support the sheet after bending, the sheet being driven by a motorized roller tractor.

If the process and the device as they come to be described, undeniably allows the realization ferrules directly from sheet rolls, respecting the radius sufficiently precisely required and the concordance of ferrules in order to obtain a rigorous sealing at each level, they do not do not, however, alone reduce the workforce of the team of specialized workers nor to have a decisive influence on the duration of the production.

The object of the present invention is to remedy these disadvantages. This invention as it is characterized in the claims, resolves the problem of defining a process and creating a device for semi-automatic production in a very short time, by a workforce of workers very small specialized, sheet metal tanks of large capacity, from sheet metal rolls trade.

1°) en ce que la réalisation des viroles est précédée des opérations suivantes:

a) Réalisation d'un fond par oxycoupage circulaire d'un assemblage de bandes de tôle préalablement solidarisées latéralement par référence à un point C, déterminé arbitrairement sur la surface de cet assemblage de tôles.

b) Matérialisation de l'axe de symétrie des viroles par soudage d'un dispositif de référence d'axe vertical Y coïncidant exactement avec le point C défini sur la surface du fond à l'étape précédente.

c) Positionnement précis, par rapport à l'axe Y du dispositif de référence, de tous les moyens concourant à l'entraínement, au défilement, au guidage, à l'accostage et au soudage des bandes de tôle et au levage de l'ensemble au fur et à mesure de la réalisation.

2°) En ce que la position verticale des galets de défilement des moyens de levage est contrôlée à distance de façon très précise, individuellement et collectivement, en fonction de la progression des opérations d'assemblage et des séquences imposées par celles-ci.

3°) En ce que la position respective des dispositifs de soudage interne et externe est indiquée en permanence de façon très précise au cours de leur utilisation, avec indication immédiate des décalages pouvant apparaítre entre les deux dispositifs, afin que ce décalage puisse être immédiatement annulé en vue de conserver en permanence une parfaite concordance des points de soudure interne et externe lors de la progression de ce cordon de soudure en corniche.

4°) En ce que la solidarisation par soudage du toit sur le chant correspondant de la virole supérieure est accompagnée de la rotation de l'ensemble sur 360° à une vitesse contrôlée compatible avec la progression idéale du cordon de soudure.

5°) En ce que le soudage de l'ensemble sur le fond est précédé de la mise en appui sur taquets mobiles du chant libre de la virole inférieure, du démontage des galets de défilement, du déplacement coordonné vers le bas des dits taquets mobiles jusqu'à mise en appui dudit chant libre de la virole inférieure, sur le pourtour du fond, puis de l'évacuation par le trou d'homme des équipements inutilisables pour cette opération finale.

The process for producing large-capacity cylindrical metal tanks on sites, from sheet metal coils using a means for driving, bending and running the sheet metal strip as well as means for transverse cutting, docking and longitudinal welding of the sheet metal strips, consisting of making the ferrules by bending, progressive bending as a function of the desired diameter, as and when the sheet metal strip is driven and unwound and successively making the ferrules from the top downwards by making each of them directly under the previous one by driving the latter in rotation by progressive joining of the sheet metal strip during forming, this joining being preceded by an equally progressive pressing of the previous ferrule on the edge of the sheet metal strip during scrolling until complete completion of the next ferrule, the roof being fixed on the upper edge of the first ferrule after completion of the latter or of the first two ferrules; the wall being secured to the bottom as soon as it has reached the desired height, is characterized, according to the invention, mainly:

1) in that the production of the ferrules is preceded by the following operations:

a) Realization of a bottom by circular flame cutting of an assembly of sheet metal strips previously joined laterally by reference to a point C, determined arbitrarily on the surface of this assembly of sheets.

b) Materialization of the axis of symmetry of the ferrules by welding a vertical axis reference device Y exactly coinciding with the point C defined on the bottom surface in the previous step.

c) Precise positioning, relative to the Y axis of the reference device, of all the means contributing to the drive, to the running, to the guidance, to the docking and to the welding of the sheet metal strips and to the lifting of the together as and when they are made.

2) In that the vertical position of the rollers of the lifting means is controlled remotely very precisely, individually and collectively, depending on the progress of the assembly operations and the sequences imposed by them.

3 °) In that the respective position of the internal and external welding devices is permanently indicated very precisely during their use, with immediate indication of the offsets that may appear between the two devices, so that this offset can be immediately canceled in order to permanently maintain a perfect concordance of the internal and external weld points during the progression of this weld bead in cornice.

4 °) In that the joining by welding of the roof on the corresponding edge of the upper shell is accompanied by the rotation of the assembly over 360 ° at a controlled speed compatible with the ideal progression of the weld bead.

5 °) In that the welding of the assembly on the bottom is preceded by the pressing on movable cleats of the free edge of the lower ferrule, the disassembly of the scroll rollers, the coordinated movement downwards of said movable cleats until the said free edge of the lower shell is pressed against the circumference of the bottom, then the evacuation through the manhole of the equipment which cannot be used for this final operation.

The device according to the invention, allowing the application of the above process, mainly characterized in that all means used for unwinding, straightening, forming, training, cutting, welding and lifting, are managed by a programmable automaton, remotely controllable by a control box without wire, respecting predetermined data.

The position of the electrodes of the welding devices is controlled by detectors connected to a monitor which measures and displays, in real time, any position differences with a view to their cancellation immediate.

The advantages obtained, thanks to this invention, basically consist of all forming, cutting, assembly and are determined in advance very precise and entered into the programmable controller before the opening of the site, while leaving operators control of the entire process of the process by means of controls non-wired remote, which makes it easy to move to sites that a very limited number of people, most often reduced to three, while reducing the completion time given prior elimination of previous downtime resulting from the preparation of settings, handling and trial and error.

• Les figures 1 à 6 illustrent schématiquement les principales étapes du procédé.
• La figure 7 représente une vue en élévation schématique d'une cuve en cours de réalisation.
• La figure 8 représente une vue de dessus schématiquement partielle d'une virole en cours de réalisation.
• La figure 9 représente une vue de dessus du système de déroulement de cambrage de découpage, d'accostage et de soudage.

Other characteristics and advantages will appear in the following description of a process and a device for producing tanks intended for the chemical industry, given by way of nonlimiting example with regard to the appended drawings, in which:

• Figures 1 to 6 schematically illustrate the main steps of the process.
• Figure 7 shows a schematic elevational view of a tank in progress.
• Figure 8 shows a schematic partial top view of a ferrule in progress.
• FIG. 9 represents a top view of the cutting, berthing and welding bending unwinding system.

The device for producing tanks, according to the invention, mainly comprises a carousel 10 consisting of a bottom 11 on which jacks 12 are mounted associated with rollers 13 , as well as an unwinder 20 consisting of a frame 21 with leveling cylinder supporting the reel holder, as well as the unwinding and bending machine 30 essentially consisting of three rollers 31 , 32 , 33 including one fixed and motorized 31 , a mobile and motorized 32 , or vice versa, ensuring , the pinching of the sheet 41 against the fixed and motorized roller 31 under the action of a jack 34 , and a non-motorized mobile 33 ensuring the bending of the sheet 41 , with control of the bending radius and of the movement of the sheet 41 by means, on the one hand, as regards the control of bending radius, of a proximity detector 50 , disposed at the top and in alignment with the bisector of the obtuse angle, formed by two arms joined to each other and com bearing, at their free end, a calibrated roller, said calibrated rollers being permanently biased against the outer face of the sheet by a compass recalled to the open position by a gas spring, and secondly, for what relates to the control of the movement of the sheet 41 , of a coding wheel 60 biased against the outer face of the sheet 41 by an arm articulated relative to the axis of connection of the end of the rod of the gas spring to the hinged element of the compass, a transverse cutting station 70 , a sheet metal docking station 80 consisting of rollers 81 located outside the carousel 10 and rollers 82 located inside thereof, in accordance with the relative to each other, a longitudinal welding station 90 , with internal 91 and external welding device 92 and a motorized roller tractor 100 .

By examining in more detail Figures 1 to 6 , illustrating the main steps of the process used, in the light of Figures 7 , 8 and 9 , we note that a first ferrule 42 is first produced by driving the sheet 41 of the coil 40 by the fixed rollers 31 and motorized presser 32 and bending of said sheet 41 by the bending roller 33 , which is positioned as a function of the radius to be obtained. The initiation of the ferrule being thus made, it is then necessary to make the zero point of the course by the precise cut from the start of the strip, then to scroll it with successive engagement on the rollers 13 of the roundabout 10 , until that the perimeter corresponding to the chosen diameter is reached, the cutting station 70 then cuts the sheet metal strip 41 to separate it from the coil 40 , the vertical assembly and the corresponding welding are then carried out, the first ferrule 42 is then completed. Then, as shown in FIG. 2 , it suffices to weld a roof 44 , then, according to FIG. 3 , to ensure the lifting of the assembly, using the jacks 12 and the rollers 13 , of a corresponding height. to the width of a strip of sheet metal, to allow, by successive engagement, the presentation of a new strip of sheet metal 41 on the rollers 13 of the cylinders 12 progressively lowered, as the sheet metal 41 travels, as show in Figures 4 and 5 , to obtain the realization of a second ferrule 43 , fully supporting the first ferrule 42 equipped with its roof 44 , as shown in Figure 6 , this by proceeding at all points as indicated above above for the production of said first ferrule 42 .

It is understood that the assembly consisting, after welding, of the ferrules 42 and 43 and of the roof 44 can be raised again using the jacks 12 associated with the rollers constituting the merry-go-round, with a view to adding a third ferrule , proceeding as illustrated in Figures 3 to 6 .

During the unwinding again, to make the additional ferrule (s) 43 , the sheet metal strip 41 is engaged, as we have just seen, under the first ferrule 42 , then approached using the rollers 81 , 82 of the station d docking 80 , which thus presses the ferrule 42 and the sheet metal strip 41 . After crossing the last roller of the docking station 80 , a welding station 90 provides automatic spot welding, as the sheet advances. The running of the sheet metal strip 41 is stopped before each post of the carousel 10 , the jack 12 supporting the ferrule is lowered, the strip advances to the next post, and so on. The cornice welding ensuring the connection and sealing between the two ferrules 42 and 43 is carried out automatically by a fixed station (not shown).

During these operations, the ferrule turns on itself using motorized roller tractors 100 , as well as under the action of motorized rollers 81 , 82 of the docking station 80 .

Now examining FIG. 9 in relation to FIGS. 7 and 8 , it is noted that, after having introduced into the programmable controller (not shown) the data relating to the diameters of ferrules to be produced and to the length of bands to be unrolled, corresponding at the perimeter of said ferrule 42 , an automatic function positions the bending roller 33 by means of the jack 35 , after engagement of the end of the sheet metal strip 41 under said roller 33 . After passing over the roller 24 , the sheet metal strip 41 is introduced onto the carousel 10 , after passing in front of the straightening means 23 , 36 , 37 and of controlling the bending and running radius 31 , 32 , 33 which will now be mentioned.

First of all, it is noted that the position of the bending roller 33 is controlled by the proximity detector 50 , which measures, in a precise manner, the distance separating it from the external surface of the sheet metal strip 41 , which makes it possible to obtain, by subtraction, the exact measurement between the calibrated support rollers of the deflection communicated to the sheet metal strip by the bending roller 33 . Corrections, more or less, are thus permanently automatically transmitted to the supply system of the jack 35 , ensuring the positioning of the bending roller 33 . The encoder wheel 60 , for its part, continuously transmits to the programmable controller via an incremental generator for example, which it drives, the exact length of sheet metal strip 41 already formed, in order to control, the opportune moment, the precise stop of the drive of the motorized rollers 31 and 32 , preceding the command to initiate the sectioning by the transverse cutting station 70 , consisting of a slide 71 with motorized carriage 72 , supporting a cutting tool 73 .

1°) La réalisation des viroles 42, 43 est précédée des opérations suivantes :

a) Fabrication d'un fond 11 par oxycoupage circulaire d'un assemblage de bandes de tôle, préalablement solidarisées latéralement, par référence à un point C déterminé arbitrairement sur la surface de cet assemblage de tôle.

b) Matérialisation de l'axe de symétrie des viroles 42, 43 par soudage d'un dispositif de référence, d'axe vertical Y coïncidant avec le point C déterminé à l'étape précédente.

c) Positionnement précis, par rapport à l'axe Y du dispositif de référence, à l'aide d'un gabarit de tous les moyens concourant à l'entraínement, au défilement, au guidage, à l'accostage et au soudage des bandes de tôle et au levage de l'ensemble au fur et à mesure de la réalisation.

2°) La position verticale des galets de défilement 13 des vérins de levage 12 est contrôlée à distance de façon très précise, individuellement et collectivement, en fonction de la progression des opérations d'assemblage et des séquences imposées par celle-ci.

3°) La position respective des dispositifs de soudage interne 91 et externe 92 est indiquée en permanence de façon très précise au cours de leur utilisation, avec indication immédiate sur un moniteur, des décalages pouvant apparaítre entre les deux dispositifs de soudage 91, 92, afin que ce décalage puisse être immédiatement annulé en vue de conserver en permanence une parfaite concordance des points de soudure interne et externe, lors de la progression du cordon de soudure en corniche.

4°) La solidarisation par soudage du toit 44 sur le chant correspondant de la virole supérieure 42 s'accompagne de la rotation de l'ensemble sur 360° à une vitesse contrôlée compatible avec la progression idéale du cordon de soudure.

5°) Le soudage de l'ensemble sur le fond 11 est précédé de la mise en appui de la virole inférieure, sur taquets mobiles se substituant aux galets de défilement 13 préalablement démontés.

Referring now again to FIGS. 1 to 6 illustrating the process, it is noted that, as has already been mentioned above:

1 °) The production of the ferrules 42 , 43 is preceded by the following operations:

a) Manufacture of a bottom 11 by circular flame cutting of an assembly of sheet metal strips, previously joined laterally, by reference to a point C arbitrarily determined on the surface of this assembly of sheet metal.

b) Materialization of the axis of symmetry of the ferrules 42 , 43 by welding of a reference device, of vertical axis Y coinciding with the point C determined in the previous step.

c) Precise positioning, relative to the Y axis of the reference device, using a template of all means contributing to the drive, scrolling, guidance, docking and welding of the strips sheet metal and lifting of the assembly as and when made.

2) The vertical position of the scroll rollers 13 of the lifting cylinders 12 is controlled remotely very precisely, individually and collectively, depending on the progress of the assembly operations and the sequences imposed by the latter.

3 °) The respective position of the internal 91 and external 92 welding devices is permanently indicated very precisely during their use, with immediate indication on a monitor, offsets which may appear between the two welding devices 91 , 92 , so that this offset can be immediately canceled in order to permanently maintain perfect concordance of the internal and external weld points, during the progression of the weld bead.

4) The joining by welding of the roof 44 on the corresponding edge of the upper shell 42 is accompanied by the rotation of the assembly over 360 ° at a controlled speed compatible with the ideal progression of the weld bead.

5 °) The welding of the assembly on the bottom 11 is preceded by the pressing of the lower ferrule, on movable tabs replacing the scroll rollers 13 previously disassembled.

It is understood that in order to obtain perfect parallelism of the ferrules 42 , 43 with one another and relative to the bottom 11 momentarily used as a reference, the actuators 12 for operating the scroll rollers 13 and the tabs (not shown) must be of strictly identical characteristics and that the oil flow rates to which they are subjected, both at the inlet and at the outlet, must be perfectly controlled in order to obtain very precise strokes of the cylinder rods.

Claims (2)

1. A method for the fabrication on site of large capacity cylindrical metal tanks from sheet metal coils (40) using a means (30) of moving, bending and unwinding the sheet of metal (41) and means of transverse cutting (70), gripping (80) and longitudinal welding (90) sheets of metal consisting of fabricating the barrels (42, 43) by means of roll bending, i.e. gradual bending to the desired diameter, as the sheet of metal (41) is moved and unwound and of fabricating the barrels (42, 43) in succession from top to bottom, fabricating each of them (42) directly under the previous one (43) and rotating it by progressively joining the sheet of metal being formed, this joining being preceded by the similarly progressive resting of the previous barrel (43) on the edge of the sheet of metal (41) as it unwinds until the following barrel (42) is completed, the top (44) being fixed to the upper edge of the first barrel (42) once it or the first two barrels have been fabricated; the wall being joined to the base (11) as soon as it reaches the desired height, characterised principally in that:

   1°) The fabrication of the barrels is preceded by the following operations:

   a) The fabrication of a base (11) by the circular oxygen cutting of an assemblage of previously laterally joined sheets of metal by reference to an arbitrarily determined point C on the surface of assemblage of metal sheets.

   b) The creation of the axis of symmetry of the barrels by welding a reference device having a vertical axis Y which coincides exactly with the point C defined on the surface of the base (11) in the preceding step.

   c) The precise positioning in relation to the Y axis of the reference device of all the means used to move, unwind, guide, grip and weld the sheets of metal and to lift the entire arrangement as it is fabricated.

   2°) The vertical position of the unwinding rollers (13) of the lifting means (12) is controlled remotely with great precision individually and collectively dependent on the progress of the assembly operations and the sequences imposed thereby.

   3°) The respective positions of the internal (91) and external (92) welding devices are continuously indicated with great precision whilst they are in use with immediate indication of any offsetting which may occur between the two devices in order that this offsetting may be remedied immediately in order to maintain a perfect match between the external and internal welding points at all times as the angle weld seam progresses.

   4°) The joining by welding of the top onto the corresponding edge of the upper barrel is accompanied by the rotation of the entire arrangement by 360° at a controlled speed compatible with the ideal progress of the welding pass.

   5°) The welding of the entire arrangement onto the base (11) is preceded by the resting of the free edge of the lower barrel (43) on mobile pads, the disassembly of the unwinding rollers (13), the co-ordinated downward movement of said mobile pads until said free edge of the lower barrel (43) rests on the periphery of the base (11), then the removal of any equipment not used for this final operation via the manhole.
2. A device for carrying out the method disclosed in claim 1 comprising means of moving, bending (30) and continuously controlling (60) said bending and unwinding the sheet of metal (41) and means of transverse cutting (70), transverse welding, gripping (80) and longitudinal welding (90) of the sheet metal, the means of driving and bending the sheet of metal (41) consisting of two motorised rollers (31, 32), one stationary (31) and the other being biased towards the former by a jack (34), and a mobile roller (33) situated upstream of the first two (31, 32) which is moved by a jack (35) depending on the curvature to be given to the sheet metal, the means of continuously controlling the bending and unwinding of the sheet of metal (41) comprising a proximity detector (50) and a encoding wheel (60) respectively; the unwinding means comprising rollers (13) associated with lifting jacks (12) distributed at regular intervals around a circumference to form a "merry-go-round" (10) with a diameter corresponding to that of the barrel (42) to be fabricated, these rollers (13) being intended to progressively support the sheet metal (41) after bending as it is moved by a tractor unit with motorised rollers (100) characterised by a programmable robot controlled remotely from a wireless control box which manages the moving means (31, 32, 34), the bending means (33, 35), the transverse cutting means (70), the continuous control and unwinding means (50, 60), the transverse cutting means (70), the welding means (90) the means for supporting the sheet metal as it unwinds (12, 13) and the tractor unit with motorised rollers (100) and by detectors linked to a monitor which measures and displays in real time any discrepancies in position so that they may be remedied immediately, controlling the position of the electrodes of the welding devices (91, 92).

Images