EP1027936A1 - Installation for spray application of water soluble paints or lacquers - Google Patents

Abstract

The system has e.g. two tanks (5A,B) which may be filled with paint or varnish in solution, ready to be sprayed, and charged to high voltage. The tanks are mounted on a carousel (4), with a dividing wall (3), which may be rotated through 180 degrees to move the filled tank into the high voltage zone. There is an earthing contact (16A,B) with a spring (18A,B) pushing a piston down onto a contact in a cylinder (17A,B). Air is admitted into the cylinder to compress the spring and break the earth contact. The tanks are heavily insulated (12A,B). An insulated cover (19) with a suction line (22) is lowered onto the top of the tank and the liquid is pumped (25) to the spray heads (6) through an insulated pipeline (30). The spray heads are connected to a high-voltage generator (40).

Description

The present invention relates to the installation for spray application of paints or varnishes water soluble through electrostatic applicators such as guns tires, bowls, discs, in conjunction with a high voltage generator and supplied with product to apply by conduits putting them in communication with a tank, which can be earthed.

Indeed, in this type of installation, it is necessary to ground it during a tank filling intervention for example, to protect response personnel, and to put the same tank under potential when electrostatic application of paint or varnish.

This type of installation is particularly intended for perform surface treatments, such as for example applying varnish to glass bottles.

In this case, it is preferable to use a water-soluble varnish, that is to say a varnish whose liquid part contains 75 to 100% water. Varnishes falling within this range are conductors of electricity, which implies that, as part of the use of an electrostatic system spraying, supply lines applicators just like the varnish tank, must be perfectly isolated from any grounded object (potential 0), soil, metal walls, but also operators who risk further shocks dangerous electrics.

When these basic precautions are not there is a leakage of current through of the tank and unacceptable losses of potential electrically at the applicator level, or even in the framework of severe leaks, the generator disjunction delivering high voltage.

Insulation of the paint or varnish tank is therefore essential to ensure correct operation of the installation.

The most common solution is to isolate the paint tank from the ground and any wall to the ground through an insulating table.

For security reasons, the table set insulating - tank is inaccessible by an operator during electrostatic spraying.

When the tank no longer contains paint or varnish, it is necessary to deactivate the high tension, so stop production to recharge the tank in paint safely, as mentioned above.

It is therefore materially impossible to carry out a continuous application of paint or varnish.

This drawback is all the more present as the tank capacities are limited by legislations, in order to limit the energy released by a accidental discharge of contained paints or varnishes in said tanks.

Therefore, depending on the varnish flow rates imposed by the size of the parts to be painted or varnish, and manufacturing rates, frequencies machine downtime is too great, and unacceptable because helping to reduce the productivity significantly.

Buffer systems exist today fitting between the live product circuit and the paint tanks kept grounded. These systems remain both complex and few reliable.

The object of the present invention is to remedy these drawbacks, and to this end concerns a installation for spray application of water-soluble paints or varnishes through electrostatic applicators, such as pneumatic guns, bowls, discs, in connection with a high voltage generator and supplied with product to be applied by conduits putting them in communication with a tank, likely to be put to the earth, characterized in that it is arranged in an enclosure defining at least two zones, of which one called "work" is accessible to staff authorized, and the other known as "high voltage" is reserved only for electrostatic application of a paint or varnish on all supports, the two zones being separated by a partition and on either side of which are arranged at least two tanks of which one filled to be operational is in the "high voltage" area, while the other empty or just filled in new is in the pending work area of a new use, the transfer of a tank initially empty and filled in the work area, towards the so-called "high voltage" area, to replace it with a tank initially full and just emptied, is carried out by swapping the two reservoirs, way to get an almost continuous supply or continuous applicators, from a single circuit supply of paint or varnish.

Not only the installation according to the invention allows a quasi-continuous supply or continuous applicators, thus a productivity gain very important but it also ensures this supply safely for the operating staff.

The present invention also relates to characteristics that will emerge during the description which will follow, and which should be considered in isolation or according to all their possible technical combinations.

• La figure 1 représente une vue en coupe transversale d'une installation complète selon l'invention.
• La figure 2 représente une vue en plan de l'installation selon la figure 1 après rotation de 90° sur elle-même.
• La figure 3 représente une vue de dessus selon la figure 2.

This description given by way of nonlimiting example will make it easier to understand how the invention can be produced with reference to the attached drawings in which:

• Figure 1 shows a cross-sectional view of a complete installation according to the invention.
• 2 shows a plan view of the installation according to Figure 1 after rotation of 90 ° on itself.
• FIG. 3 represents a top view according to FIG. 2.

According to the invention, the installation 1 designated in the whole is arranged in an enclosure 2 defining at least two zones 2A, 2B, one of which 2A so-called "work" is accessible to personnel authorized, and the other 2B known as "high voltage" is reserved for electrostatic application only a paint or varnish on all supports. According to a first embodiment shown on Figures 1 to 3, the two areas 2A, 2B are separated by a central partition 3 arranged on a turntable 4 and on either side of which are arranged at minus two supply tanks 5A, 5B, of which one 5B filled to be operational is in the "high voltage" zone 2B, while the other 5A is empty or just refilled is in the area 2A work waiting for a new use. Still according to this same example, the transfer of a 5A tank initially empty and filled in the work 2A, towards the so-called "high voltage" area 2B, to replace it with a 5B tank initially full and just emptied, is performed by rotation at 180 ° of the turntable 4 supporting the two tanks 5A, 5B, so as to obtain a almost continuous supply of applicators 6, to from a single paint supply circuit or varnish.

Such an arrangement not only ensures in this case a quasi-continuous supply of applicators 6, but also helps to ensure the safety of operating personnel, because indeed this personnel can only have access to zone 2A known as "work", thus isolated from any element of the installation may be under high voltage.

The transfer of a tank from an area to a other can of course be done manually or automatically via a motor electric 7 able to rotate the plate rotary 4.

As shown in Figure 3, the partition median 3 is arranged perpendicular to the turntable 4, which is horizontal, and on which it is fixed. The width of said partition 3 is equivalent to the diameter of said plate 4.

When the partition 3 is in the fixed position, it extends by mesh barriers 8 on both sides and on the other side of the plate 4, thus delimiting the zones of work 2A and high voltage 2B, extending beyond the partition 3, which constitutes a movable part of the separation of the two zones 2A, 2B.

The rotation of the turntable 4 can be made easier by arranging a series of 9 sous casters its lower plane, substantially peripheral.

As shown in Figure 1, the turntable 4 has two weighing scales 10A, 10B with adjustment of tare, on which the tanks are arranged 5A, 5B and which are associated with two sensors correspondent 11A, 11B capable of detecting a position high, of each of the rockers 10A, 10B corresponding to the tare, which itself corresponds to the weight of a empty tank 5A or 5B.

The two tanks 5A, 5B are produced in a electrically conductive material and are integrated removably in corresponding tanks 12A, 12B made of an insulating material. The tanks 12A, 12B are made of an insulating material of rigidity very high electrical, such as polypropylene by example.

According to the present embodiment, these tanks with integrated conductive tanks are arranged at 180 ° from each other on the plate 4.

Of course, one could also imagine a installation with three tanks forming an angle of 120 ° relative to each other, for example by providing two high-voltage zones and a work zone.

We can also imagine an installation at drawer in which the two tanks 5A, 5B are arranged on a plate (not shown) sliding at the way of a drawer inside a high area fixed and inaccessible voltage, free working area lying alternately on either side of said high voltage area.

Anyway, each of the tanks 12A, 12B has a spring leaf on its internal bottom metallic 13A, 13B intended to cooperate with a wall external of the bottom of the corresponding tank 5A, 5B and in connection with a discharge resistor 14A, 14B by one of its poles, the other pole being linked electric with an external socket 15A, 15B of the tank 12A, 12B for connection with a device earthing 16A, 16B of said tanks paint 5A, 5B.

Advantageously, discharge resistors 14A, 14B are integrated into the mass of the insulating material constituting the tanks 12A, 12B.

It should be noted that the paint tanks or 5A, 5B varnishes are preferably made of steel stainless and they are studied so that they can be easily integrated manually, if required, in tanks 12A, 12B.

According to another characteristic of the invention, the earthing device 16A, 16B of each tank 5A, 5B consists of a pneumatic cylinder 17A, 17B mounted in positive safety thanks to a reminder by spring 18A, 18B integrated into the body of said cylinder, grounding occurs when it is not does not inject compressed air A, the tank not being then not operational, or by injecting air compressed A in the cylinder body, having the effect cancel the grounding of tank 5B when this supplies the electrostatic applicators 6 being applied.

According to another characteristic of the invention, a cover 19 of insulating material is placed in the high voltage area 2B, and is connected to a up and down 20 permanently located in said zone 2B so as to cap an operational tank 12B there finding or releasing it when empty for transfer by 180 ° rotation, or by sliding in drawer towards the work area.

The up and down system 20 consists of a pneumatic cylinder 21 for example, capable of acting according to an upper stroke of more than 300mm from the height of the tank 12B. Of course, this operation can if necessary be done manually.

• Une canne 22 d'aspiration de la peinture ou vernis 23 contenu dans le réservoir opérationnel 5B, intégrant un tamis 24 et éventuellement un clapet anti-retour (non représenté), plongeant par son extrémité libre 22a au fond du réservoir 5B et reliée à son autre extrémité à une pompe d'aspiration 25 et aux applicateurs électrostatiques 6.
• un agitateur à motorisation pneumatique 26.

According to another characteristic of the invention, the cover 19 comprises traversing elements fixedly mounted and which consist of:

• A cane 22 for suctioning the paint or varnish 23 contained in the operational tank 5B, incorporating a screen 24 and possibly a non-return valve (not shown), plunging through its free end 22a into the bottom of the tank 5B and connected to its other end to a suction pump 25 and to the electrostatic applicators 6.
• a pneumatically driven agitator 26.

According to an improvement of the invention, the free end 22a of the suction rod 22 is rigidly associated with a reserve cup 27 in which it dives and which is of a capacity predetermined so that when the tank 5B initially full is emptied and that the cover 19 is raised for the transfer of the tank 12B, the reserve of paint or varnish 23 contained in the cup 27 allows not to interrupt the power of the applicators 6, if only the transfer time, and therefore get a feed continues of these.

According to another characteristic of the invention, the cover 19 further includes a setting device 28 under controlled voltage of operational tank 5B, implemented when the cover 19 is closed and which consists of a metal sleeve 29 inserted on a supply line 30 under voltage extending the suction rod 22 towards the pump 25 and electrically connected to a pole of a resistance of discharge 31, the other pole thereof being connected to a conductive element 32 in electrical contact with a part of tank 5B.

According to the embodiment shown, the conductive element 32 is a metal chain passing through the cover 19 and hanging inside the operational tank 5B, its length being slightly greater than that of the suction rod 22 of way to come into electrical contact with the bottom of said reservoir 5B when the lid is closed.

According to an alternative embodiment, the element conductor 32 is a through metal chain said cover 19, its length being slightly higher than that of the suction rod, so that the free end of the chain comes in electrical contact with the bottom of a container conductor solidly disposed inside said tank 5B near its upper edge, above the maximum upper level of paint or varnish and able to contain the whole chain, this contact made prior to contact end of the suction rod 22 with the upper plane of the paint or varnish when the lowering of the cover 19, in order to avoid any possibility of an electric arc between the end of the chain or suction rod 22 and the painting, during this closing phase of the lid.

According to another alternative embodiment, the element conductor is arranged outside the cover, jointly and severally with it rising and falling, and slightly longer than the cane suction 22, so that its end come into electrical contact with another element external conductor integral with the insulating tank 12B but electrically connected to the discharge resistance 14B itself in electrical connection with the bottom of the metal tank 5B, so that this placing under voltage of external conductive elements, hence tank, made before contact end of the suction rod 22 with the upper plane of the paint or varnish when the descent of the cover 19, thus avoiding any possibility of electric arc during this contact.

According to an example of application of this variant, the external conductive element integral with the cover is a chain able to fit in a container constituting the other conductive element integral with the insulating tank.

According to a second example of application of this same variant, the external conductive element is a rigid rod capable of cooperating in sliding with a ring constituting the other integral conductive element of the insulating tank.

Finally, a flexible conduit 33 made of plastic of high electrical rigidity connects the pump pneumatic 25, preferably made of plastic, electrostatic applicators 6.

All of the conduits located between said electrostatic applicators 6 and the cover 19 is isolated from the mass by an insulating material 34 of high electrical rigidity.

The installation also includes a drip tray 35 intended to be placed under the cover 19 carrying the chain 32, the agitator 26 and the suction rod 22 equipped with the reserve dish 27, this when the cover is removed from the tank 12B, for the transfer thereof.

The drip tray 35 is made mobile by manual or preferably pneumatic action, by via an actuating cylinder 36.

In order to perfect the understanding of the above installation, the procedure below will be a description of its operating cycle, knowing that this cycle could be advantageously performed automatically.

This is a turntable installation according to Figures 1 to 3 and whatever the device of controlled power used, knowing that the operating principle will be the same for a drawer installation.

• A = automatique
• M = manuelle
• A/M = manuelle ou automatique

Note that the abbreviations used below have the following meanings:

• A = automatic
• M = manual
• A / M = manual or automatic

System preparation phase

• Un opérateur s'est assuré que les deux bascules 10A et 10B ont été tarées de manière à ce que les deux capteurs 11A et 11B soient désactivés lorsque la masse pesée équivaut à la masse de l'ensemble 12 ou 12A, 19, 26, 28, 31, 27, 24, 32, quantité de vernis 23 en niveau bas). On considère comme niveau bas le niveau haut du réservoir 27 de la canne d'aspiration 22.
• Les réservoirs 12A et 12B sont vides.
• Les capteurs 11A et 11B sont activés (détectent un niveau bas de vernis 23).
• Le couvercle 19 est en position haute.
• Le bac anti-égouttures 35 est activé et se trouve au-dessous du couvercle 19, de la réserve 27 et de la canne 22 de l'agitateur 26 et de la chaínette 32.
• L'agitateur 26 et la pompe 25 sont désactivés.
• Les circuits produits 33 ont été préalablement gavés de vernis 23 et purgés.
• Le système de mise à la terre 16A n'est pas alimenté en air comprimé (liaison du réservoir 5A avec la terre T).
• Le système de mise à la terre 16B est alimenté en air comprimé (réservoir 5B non relié à la terre T).
• Le générateur haute tension 40 est désactivé.

It is assumed that, in this first phase:

• An operator has made sure that the two scales 10A and 10B have been tared so that the two sensors 11A and 11B are deactivated when the weighed mass equals the mass of the assembly 12 or 12A, 19, 26, 28 , 31, 27, 24, 32, amount of varnish 23 at low level). The high level of the reservoir 27 of the suction rod 22 is considered to be a low level.
• The tanks 12A and 12B are empty.
• The sensors 11A and 11B are activated (detect a low level of varnish 23).
• The cover 19 is in the high position.
• The anti-drip tray 35 is activated and is located below the cover 19, the reserve 27 and the cane 22 of the agitator 26 and the chain 32.
• The agitator 26 and the pump 25 are deactivated.
• The product circuits 33 were previously stuffed with varnish 23 and purged.
• The earthing system 16A is not supplied with compressed air (connection of the tank 5A with the earth T).
• The earthing system 16B is supplied with compressed air (tank 5B not connected to earth T).
• The high voltage generator 40 is deactivated.

Manual or automatic preparation phases

• Filling of tank 5A in the working area 2A.
• Sensor 11A is deactivated (A) because the tank 5A is full.
• Deactivation of 16B.
• Rotation of the plate 4 on an angle of 180 ° (A / M), the reservoir 5A therefore passes into the high voltage zone 2B.
• Activation of 16A (A / M), which has passed into the zone 2B.
• The drip tray 35 is removed (A / M).
• The cover 19 goes down (A / M).
• The agitator 26 is activated (A).
• The high voltage generator 40 is activated (A).
• Pump 25 is activated (A).
• Applicator valves open electrostatic 6: the varnish 23 is applied.

Typical stages of a cycle.

1. Arrêt de l'agitateur 26 (M/A).

2. Montée du couvercle 19 (M/A).

3. Mise en place du bac anti-égouttures 35 (M/A).

4. Coupure de l'air comprimé du système de la mise à la terre 16B, le reste du produit contenu dans le réservoir 5B est donc mis à la terre (M/A).

5. Rotation à 180° du plateau 4 (manuellement ou par le moteur 7) : la cuve 12A prend la place de la cuve 12B, et vice versa (M/A).

6. Alimentation en air comprimé du système de la mise à la terre 16A pour isoler le produit contenu dans le réservoir 5A (M/A).

7. Retrait du bac anti-égouttures 35 (M/A).

8. Descente du couvercle 19 (M/A).

9. Le vernis 23 se trouvant dans le réservoir 5A ayant pris la place du réservoir 5B, est mis au même potentiel que le vernis se trouvant dans la canalisation 33 via la chaínette 32 : l'arc électrique est ainsi évité grâce à la résistance de décharge 31.

10. La réserve 27 de la canne 22 contenant un reste de vernis chargé est plongée dans le vernis contenu dans le réservoir 5A.

11. Mise en route de l'agitateur 26 (M/A).

12. Un opérateur (ou plus avantageusement un système automatique de remplissage) remplit alors le réservoir 5B qui a pris la place du réservoir 5A en toute sécurité. Le capteur 11B est alors désactivé et la quantité de vernis 23 est prête pour un nouveau transfert en zone haute tension 2B. Lorsque le capteur 11A du réservoir 5A se trouvant en zone haute tension 2B détecte un niveau bas de vernis (capteur activé), et que le capteur 11B du réservoir 5B se trouvant en attente en zone de travail 2A est désactivé, (si 11B n'est pas désactivé, on déclenche un arrêt production).

13. Arrêt de l'agitateur 26 (M/A).

14. Montée du couvercle 19 (M/A).

15. Mise en place du bac anti-égouttures 35 (M/A).

16. Coupure de l'air comprimé du système de mise à la terre 16A : le reste du produit contenu dans le réservoir 5A se trouvant en zone haute tension 2B est mis à la terre (M/A).

17. Rotation à 180° du plateau 40 (manuellement ou via le moteur 7) : la cuve 2A reprend sa position initiale à la place de la cuve 2B et vice versa.

18. Alimentation en air comprimé du système de la mise à la terre 16B pour isoler le produit contenu dans le réservoir 5B par rapport à la terre (M/A).

19. Retrait du bac anti-égouttures 35 (M/A).

20. Descente du couvercle 19 (M/A).

21. Le vernis 23 dans le réservoir 5B est porté au même potentiel que le vernis se trouvant dans la canalisation 33 via la chaínette 32. L'arc électrique est évité grâce à la résistance de décharge 31.

22. La réserve 27 de la canne 22, contenant un reste de vernis chargé, est plongée dans le vernis du réservoir 5B.

23. Mise en route de l'agitateur 26 (M/A), jusqu'à vider le réservoir 5B.

24. Retour à l'étape 1 si le capteur 11A est désactivé, ce qui correspond à un réservoir 5A plein (sinon arrêt production).

When the sensor 11B detects a low level of the varnish (sensor activated), in the reservoir 5B located in the high voltage zone 2B .

1. Stopping of the agitator 26 (M / A).

2. Mount cover 19 (M / A).

3. Installation of the drip tray 35 (M / A).

4. Disconnection of the compressed air from the earth system 16B, the rest of the product contained in the tank 5B is therefore earthed (M / A).

5. 180 ° rotation of plate 4 (manually or by motor 7): tank 12A takes the place of tank 12B, and vice versa (M / A).

6. Supply of compressed air to the 16A earthing system to isolate the product contained in the 5A tank (M / A).

7. Removal of the drip tray 35 (M / A).

8. Lower the cover 19 (M / A).

9. The varnish 23 located in the reservoir 5A having taken the place of the reservoir 5B, is set to the same potential as the varnish being in the pipeline 33 via the chain 32: the electric arc is thus avoided thanks to the resistance of discharge 31.

10. The reserve 27 of the rod 22 containing a remainder of loaded varnish is immersed in the varnish contained in the reservoir 5A.

11. Start up of agitator 26 (M / A).

12. An operator (or more advantageously an automatic filling system) then fills the reservoir 5B which has taken the place of the reservoir 5A in complete safety. The sensor 11B is then deactivated and the quantity of varnish 23 is ready for a new transfer to the high voltage zone 2B. When the sensor 11A of the reservoir 5A located in the high voltage zone 2B detects a low level of varnish (sensor activated), and the sensor 11B of the reservoir 5B being on standby in the working zone 2A is deactivated, (if 11B does not is not deactivated, a production stop is triggered) .

13. Stirrer 26 (M / A) stopped.

14. Mount cover 19 (M / A).

15. Installation of the drip tray 35 (M / A).

16. Disconnection of the compressed air from the earthing system 16A: the rest of the product contained in the tank 5A located in the high voltage zone 2B is earthed (M / A).

17. 180 ° rotation of the plate 40 (manually or via the motor 7): the tank 2A returns to its initial position in place of the tank 2B and vice versa.

18. Compressed air supply to the 16B earthing system to isolate the product contained in the tank 5B from the earth (M / A).

19. Removal of the drip tray 35 (M / A).

20. Lower the cover 19 (M / A).

21. The varnish 23 in the reservoir 5B is brought to the same potential as the varnish in the pipeline 33 via the chain 32. The electric arc is avoided thanks to the discharge resistance 31.

22. The reserve 27 of the rod 22, containing a residue of loaded varnish, is immersed in the varnish of the reservoir 5B.

23. Start of agitator 26 (M / A), until emptying of the tank 5B.

24. Return to step 1 if the sensor 11A is deactivated, which corresponds to a full 5A tank (otherwise production stop).

All of these maneuvers allow a continuous supply of varnishes. The capacity of the reserve 27 at the end of the rod 22 is studied so as to what in the context of maximum flow rates on the line of application, it does not dry up before execution of the above steps.

Claims (16)

Installation for application by spraying of water-soluble paints or varnishes done through applicators electrostatic (6) such as pneumatic guns, bowls, discs in connection with a high generator voltage (40) and supplied with product to be applied (23) by conduits putting them in communication with a tank, capable of being earthed, characterized in that it is arranged in a enclosure (2) defining at least two zones (2A, 2B), one of which (2A) called "work" is accessible to a authorized personnel, and the other (2B) called "high voltage "is for application only electrostatic of a paint or varnish on all supports, the two zones (2A, 2B) being separated by a partition (3) on either side of which are arranged at least two supply tanks (5A, 5B), one of which (5B) completed to be operational is in the "high voltage" area (2B), while the other (5A) empty or just refilled found in the work area (2A) waiting for a new use, the transfer of a tank (5A) initially empty and filled in the work area (2A), towards the so-called "high voltage" area (2B), in order to replace an initially full tank (5B) and just emptied, is performed by permutation of the two tanks (5A, 5B), so as to obtain a almost continuous or continuous supply of applicators (6), from a single circuit supply of paint or varnish. Installation according to claim 1, characterized in that the two tanks (5A, 5B) are arranged on a plate (4) rotating 180 ° in one way or the other, and separated from each other by a central partition (3) delimiting the work areas and high voltage (2A, 2B). Installation according to claim 1, characterized in that the two tanks (5A, 5B) are arranged on a tray (not shown) sliding like a drawer inside a fixed and inaccessible high voltage area, the free work alternating between and on the other side of said high voltage zone. Installation according to claims 1 to 3, characterized in that the plate (4) has two weighing scales (10A, 10B) with tare adjustment, on which tanks (5A, 5B) are arranged and which are associated with two corresponding sensors (11A, 11B) capable of detecting a high position, of each of the scales (10A, 10B) corresponding to the tare weight, which itself corresponds to the weight of an empty tank (5A or 5B). Installation according to one of claims 1 to 4, characterized in that the two reservoirs (5A, 5B) are made of a conductive material electricity and are removably integrated into corresponding tanks (12A, 12B) produced in a insulating material. Installation according to claim 5, characterized in that each of the tanks (12A, 12B) has a spring leaf on its internal bottom metallic (13A, 13B) intended to cooperate with a outer wall of the bottom of the corresponding tank (5A, 5B) and in connection with a discharge resistor (14A, 14B) by one of its poles, the other pole being in electrical connection with an external socket (15A, 15B) of the tank (12A, 12B) for connection with a earthing device (16A, 16B) of said paint tanks (5A, 5B). Installation according to claim 6, characterized in that the earthing device (16A, 16B) of each tank (5A, 5B) is made up by a pneumatic cylinder (17A, 17B) securely mounted positive thanks to a spring return (18A, 18B) integrated into the body of said cylinder, earthing when it is not blown with air compressed (A), the tank then not operational, or on the contrary by injecting air compressed (A) in the cylinder body, having the effect cancel the grounding of the tank (5B) when this supplies the electrostatic applicators (6) being applied. Installation according to one of the claims previous, characterized in that a cover (19) in insulating material is placed in the upper area voltage (2B), and is connected to a mounting system and drop (20) permanently located in said zone (2B) of so as to cap an operational tank (12B) there finding or releasing it when empty for its transfer by rotation, or by sliding in drawer towards the working area (2A). Installation according to claim 8, characterized in that the cover (19) comprises through elements fixedly mounted and which consist of: A cane (22) for sucking up the paint or varnish (23) contained in the operational tank (5B), integrating a screen (24) and possibly a non-return valve (not shown), plunging through its free end (22a ) at the bottom of the reservoir (5B) and connected at its other end to a suction pump (25) and to the electrostatic applicators (6). a motorized agitator (26). Installation according to claim 9, characterized in that the free end (22a) of the suction rod (22) is rigidly associated with a reserve cup (27) into which it plunges and which is of a predetermined capacity so that only when the initially full tank (5B) is emptied and the cover (19) is lifted for the transfer from the tank (12B), the paint reserve or varnish (23) contained in the cup (27) allows do not interrupt the supply of the applicators (6), if only for the time of the transfer. Installation according to claim 9 or 10, characterized in that the cover (19) includes in addition to a device (28) for controlled tensioning operational tank (5B), used during closing the cover (19) and which is constituted by a metal sleeve (29) inserted on a pipe supply (30) under tension extending the rod suction (22) to the pump (25) and connected electrically to a pole of a discharge resistor (31), the other pole of the latter being connected to an element conductor (32) in electrical contact with a part of the tank (5B). Installation according to claim 11, characterized in that the conductive element (32) is a metal chain passing through the cover (19) and hanging inside the operational tank (5B), its length being slightly greater than that of the suction rod (22) so as to come into electrical contact with the bottom of said tank (5B) when the cover is closed. Installation according to claim 11, characterized in that the conductive element (32) is a metal chain passing through said cover (19), its length being slightly greater than that of the suction rod, so that the free end of the chain comes into contact electric with the bottom of a conductive container arranged integrally inside said tank (5B) near its upper edge, above the maximum upper level of paint or varnish and suitable to contain the whole chain, this contacting taking place before the electrical contact of the end of the suction rod (22) with the plane top of the paint or varnish during the descent of the cover (19), in order to avoid any possibility an electric arc between the end of the chain or of the suction rod (22) and the paint, when this phase of closing the cover. Installation according to claim 6 and 11, characterized in that the conductive element is arranged outside the cover, integral with it up and down, and slightly longer higher than that of the suction rod (22), so that its end comes into contact electric with another external conductive element integral with the insulating tank (12B) but connected electrically to the discharge resistor (14B) itself in electrical connection with the bottom of the tank metallic (5B), so that this energization of the external conductive elements, hence the reservoir, takes place prior to the electrical contact of the end of the suction rod (22) with the plane top of the paint or varnish during the descent of the cover (19), thus avoiding any possibility electric arc during this contact. Installation according to claim 14, characterized in that the external conductive element secured to the cover is a chain suitable for stay in a container constituting the other element conductor integral with the insulating tank. Installation according to claim 14, characterized in that the external conductive element is a rigid rod able to cooperate in sliding with a ring constituting the other conducting element integral with the insulating tank.

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