EP3866986B1 - Fluid-spraying facility and method for moving an associated fluid - Google Patents

Description

The present invention relates to a fluid projection installation. The present invention also relates to a method for moving a fluid in such a fluid projection installation.

Fluid projection installations are used in numerous applications, in particular for projecting paints or other coating products. In these installations, the fluid to be projected circulates in a conduit as far as a projection device such as a gun.

It is frequently necessary to clean the inside of the fluid circulation duct to remove all traces of the fluid, for example to prevent a deposit from appearing in the event of prolonged non-use of the installation or, in the event that various fluids are likely to be projected successively by the same installation, to avoid any contamination of the fluid by traces of the previously projected fluid.

The cleaning of the inside of the duct is generally carried out using a scraper, that is to say an instrument intended to circulate in the duct in order to remove any trace of the fluid present by rubbing against the inner surface of the duct. The scrapers are generally instruments comprising at least cylindrical portions having a diameter equal to the internal diameter of the duct. The cylindrical portions are, for example, elastomeric seals which rub against the inner surface of the conduit. The scraper seals between its upstream part and its downstream part. It then pushes the fluid present in front of it to a portion of the conduit provided to allow the recovery or evacuation of the fluid thus collected.

However, the use of such scrapers generates significant wear both of the scrapers themselves and of the ducts in which they circulate, since the scrapers rub against the inner surface of the duct each time they pass. This results in a need to frequently replace the scrapers and the circulation duct.

The object of the invention is to provide a fluid spraying installation which requires less maintenance than the paint spraying installations of the state of the art.

To this end, the subject of the invention is a fluid spraying installation comprising a fluid circulation conduit and a scraper able to circulate in the conduit, the scraper being configured to push the fluid present in the conduit in front of it when the scraper circulates in the conduit, the conduit and the scraper each having a cylindrical section, the conduit having an internal diameter, the scraper having an external diameter, the external diameter having a first value, a difference between the internal diameter of the conduit and the first outer diameter value of the scraper being greater than or equal to 100 micrometers, preferably greater than or equal to 200 micrometers, the installation comprising a holding system capable of preventing relative translational movement of the scraper with respect to the duct when the scraper is inserted into the duct, the duct extending along a first axis, the scraper extending along a second axis and being configured to move in translation relative to the duct along the first axis when the first axis and the second axis coincide, the holding system being configured to rotate the scraper about an axis perpendicular to the first axis such that an angle between the first axis and the second axis is strictly greater than zero, preferably greater than or equal to 0.5 degrees.

• le racleur comprend un aimant présentant un pôle nord et un pôle sud, les pôles de l'aimant étant alignés selon un troisième axe, un angle entre le deuxième axe et le troisième axe étant strictement supérieur à zéro, de préférence supérieur ou égal à 5 degrés, le système de maintien comportant un générateur de champ magnétique propre à générer dans au moins une portion du conduit un champ magnétique tendant à aligner le troisième axe et le premier axe.
• le générateur de champ magnétique est en contact avec une surface extérieure du conduit de circulation.
• le générateur de champ magnétique est au moins partiellement compris entre une surface intérieure et une surface extérieure du conduit de circulation.

According to other advantageous but not obligatory aspects of the invention, the fluid projection installation comprises one or more of the following characteristics, taken in isolation or in all technically possible combinations:

• the scraper comprises a magnet having a north pole and a south pole, the poles of the magnet being aligned along a third axis, an angle between the second axis and the third axis being strictly greater than zero, preferably greater than or equal to 5 degrees, the holding system comprising a magnetic field generator suitable for generating in at least a portion of the conduit a magnetic field tending to align the third axis and the first axis.
• the magnetic field generator is in contact with an outer surface of the circulation conduit.
• the magnetic field generator is at least partially included between an interior surface and an exterior surface of the circulation duct.

The invention also relates to a method for moving a fluid in a fluid projection installation comprising a fluid circulation conduit, comprising a step of circulation of a scraper in the conduit, the scraper pushing fluid in front of it present in the conduit during the circulation step, the conduit and the scraper each having a cylindrical section, the conduit having an internal diameter, the scraper having an external diameter, the external diameter having a first value during the step of circulation, a difference between the internal diameter of the duct and the first external diameter value of the scraper is greater than or equal to 100 micrometers, preferably greater than or equal to 200 in which the duct extends along a first axis, the scraper extending along a second axis and being configured to circulate in translation relative to the duct along the first axis when the first axis and the second axis coincide, the method comprising a pivoting step, by a holding system capable of preventing a movement of relative translation of the scraper with respect to the duct when the scraper is inserted into the duct, of the scraper around an axis perpendicular to the first axis of such that an angle between the first axis and the second axis is strictly greater than zero, preferably greater than or equal to 0.5 degrees.

• la figure 1 est une représentation schématique d'un premier exemple d'installation de projection de fluide comprenant un conduit de circulation de fluide et un racleur,
• la figure 2 est une représentation schématique partielle en coupe du premier exemple d'installation de projection de fluide,
• la figure 3 est une représentation schématique partielle en coupe d'un deuxième exemple d'installation de projection de fluide,
• la figure 4 est une représentation schématique partielle en coupe d'un troisième exemple d'installation de projection de fluide comprenant un conduit, une pression dans le conduit étant égale à une première valeur, l'installation selon ce troisième exemple n'étant pas couverte par le texte des revendications,
• la figure 5 est une représentation schématique partielle en coupe de l'installation de la figure 4, la pression dans le conduit étant égale à une deuxième valeur strictement supérieure à la première valeur,
• la figure 6 est une représentation schématique partielle en coupe d'une variante du troisième exemple d'installation de projection de fluide, la pression dans le conduit étant égale à la deuxième valeur, l'installation selon cette variante n'étant pas couverte par le texte des revendications,
• la figure 7 est une représentation schématique d'un autre exemple d'installation de projection de fluide, et
• la figure 8 est une représentation schématique partielle d'un autre exemple d'installation de projection de fluide, l'installation selon cet exemple n'étant pas couverte par le texte des revendications.

Characteristics and advantages of the invention will appear on reading the following description, given solely by way of non-limiting example, and made with reference to the appended drawings, in which:

• there figure 1 is a schematic representation of a first example of a fluid projection installation comprising a fluid circulation conduit and a scraper,
• there figure 2 is a partial cross-sectional schematic representation of the first example of a fluid projection installation,
• there picture 3 is a partial schematic sectional representation of a second example of a fluid projection installation,
• there figure 4 is a partial schematic cross-sectional representation of a third example of a fluid projection installation comprising a conduit, a pressure in the conduit being equal to a first value, the installation according to this third example not being covered by the text demands,
• there figure 5 is a partial cross-sectional schematic representation of the installation of the figure 4 , the pressure in the duct being equal to a second value strictly greater than the first value,
• there figure 6 is a partial schematic cross-sectional representation of a variant of the third example of fluid projection installation, the pressure in the conduit being equal to the second value, the installation according to this variant not being covered by the text of the claims ,
• there figure 7 is a schematic representation of another example of a fluid projection installation, and
• there figure 8 is a partial schematic representation of another example of a fluid projection installation, the installation according to this example not being covered by the text of the claims.

A first example of a fluid projection installation 10 is represented on the figure 1 .

The installation 10 is configured to project a first fluid F.

The installation 10 comprises, for example, a color changer block 11, a pump 12 and a member 13 for spraying the first fluid F such as a paint gun or even a sprayer.

The installation 10 further comprises a conduit 15 for circulation of fluid F, a scraper 20 and at least one injector 21.

The color changer block 11, the pump 12, the circulation conduit 15 and the projection member 13 together form a circuit 16 for the circulation of the first fluid F. The circuit 16 is in particular capable of conducting the first fluid F from the block color changer 11 to the projection device 13.

The first fluid F is, for example, a liquid, such as a paint or another coating product.

According to one embodiment, the first fluid F comprises a set of electrically conductive particles, in particular metallic particles, such as aluminum particles.

The color changer block 11 is configured to supply the pump 12 with the first fluid F. In particular, the color changer block 11 is configured to supply the pump 12 with a plurality of first fluids F, and to switch the supply of the pump 12 from a first fluid F to another first fluid F.

In particular, each of the first fluids F with which the color changer unit 11 is suitable for supplying the pump 12 is, for example, a paint having a different color from the colors of the other first fluids F.

The pump 12 is capable of injecting into the circulation conduit 15 a flow of the first fluid F received from the color changer block 11. For example, the pump 12 is connected to the circulation conduit 15 by a valve 14.

The pump 12 is, for example, a gear pump.

The projection member 13 is suitable for receiving the first fluid F and for projecting the first fluid F.

For example, the projection member 13 comprises a valve 22 and a sprayer head 23.

The projection member 13 is, for example, mounted on a mobile arm able to orient the projection member 13 in the direction of an object on which the first fluid F is to be projected.

The valve 22 is configured to connect the circulation conduit 15 to the sprayer head 23, and to switch between an open configuration allowing the passage of first fluid F from the circulation conduit 15 to the sprayer head 23 and a closed configuration preventing this passage.

The sprayer head 23 is configured to project the first fluid F received from the valve 22.

The fluid circulation conduit 15 is configured to conduct the first fluid F received from the valve 14 to the projection member 13.

The fluid circulation conduit 15 is cylindrical. For example, the fluid circulation conduit 15 has a circular section and extends along a first axis A1.

According to one embodiment, the fluid circulation conduit 15 is rectilinear. Alternatively, the fluid circulation conduit 15 is a curved conduit for which the first axis A1 is defined locally at any point of the fluid circulation conduit 15 as being perpendicular to a plane in which the section of the fluid circulation conduit 15 is circular.

The fluid circulation conduit 15 has an internal surface 25 delimiting a lumen of the fluid circulation conduit 15 in a plane perpendicular to the first axis A1.

The fluid circulation conduit 15 further has an outer surface 27, which is visible on the picture 3 . In order to simplify the figure 1 , 2 And 4 to 7 , the outer surface 27 is shown only on the figure 3 .

There is defined an upstream and a downstream for the circulation conduit 15. The upstream and the downstream are defined in that, during the projection of the first fluid F, the first fluid F circulates in the circulation conduit 15 from the upstream to downstream.

For example, the pump is configured to inject the first fluid F at an upstream end 15A of the circulation conduit 15 while a downstream end 15B of the circulation conduit 15 is connected to the sprayer to allow the first fluid F to circulate from the upstream to downstream from the pump to the sprayer through the circulation conduit 15. This is shown in the figure 1 by an arrow 26.

According to the example shown in the figure 1 , the fluid circulation conduit 15 comprises a first portion 28 and a second portion 29.

The circulation duct 15 has a length greater than or equal to 50 centimeters, for example greater than or equal to one meter. According to one embodiment, each of the first portion 28 and of the second portion 29 has a length greater than or equal to one meter.

The first portion 28 is arranged upstream of the second portion 29.

The first portion 28 is, for example, configured to deform so as to follow the movement of the projection member 13.

The second portion 28 is, for example, accommodated in the projection member 13 and movable with it.

The second portion 29 is, for example, helical.

An internal diameter Di is defined for the fluid circulation conduit 15. The internal diameter Di is measured in a plane perpendicular to the first axis A1 between two diametrically opposite points of the internal surface 25.

The internal diameter Di is, for example, between 3.8 and 6.2 mm. It should be noted that the internal diameter Di of the circulation duct 15 is likely to vary.

The fluid circulation conduit 15 is, for example, made of a metallic material. Alternatively, the fluid circulation conduit 15 is made of a polymer material.

The scraper 20 is configured to circulate in the fluid circulation conduit 15 in order to push the first fluid F present on the internal surface 25 in front of it during its movement in the fluid circulation conduit 15. In particular, the scraper 20 is configured to clean the internal surface 25, that is to say to leave behind an internal surface 25 covered with a quantity of first fluid F less than the quantity covering the internal surface 25 before the passage of the scraper 20, for example to remove all of the first fluid F covering the internal surface 25 of the portions of the duct 15 in which the scraper 20 circulates.

It is understood by “pushing in front of it” that the scraper 20, circulating in one direction in the fluid circulation conduit 15, imposes a movement in this direction on the first fluid F which is received in the portion of the conduit 15 in the direction of which the scraper 20 moves. For example, a scraper 20 moving from upstream to downstream imposes on the first fluid F located downstream of the scraper 20 a downstream movement.

The scraper 20 extends along a second axis A2.

The scraper 20 comprises at least one portion having a circular section in a plane perpendicular to the second axis A2.

According to the example of figure 2 , the scraper 20 is substantially cylindrical and has a symmetry of revolution around the second axis A2.

The scraper 20 is provided to circulate in the circulation duct 15 when the scraper 20 is received in the lumen of the circulation duct 15 and the first axis A1 coincides with the second axis A2, as represented on the figure 2 .

The scraper 20 has an outer diameter. The outer diameter is the outer diameter of the portion of scraper 20 having the largest outer diameter in a plane perpendicular to the second axis A2.

The external diameter has a first value De1.

The first value De1 is strictly less than the internal diameter Di of the circulation conduit 15.

A difference between the internal diameter Di of the circulation conduit 15 and the first value De1 is greater than or equal to 100 micrometers (μm). For example, the difference is greater than or equal to 200 µm.

The difference is less than or equal to 300 µm.

According to one embodiment, the difference is equal to 200 μm.

The scraper 20 has two end faces 30 delimiting the scraper 20 along the second axis A2. A length of the scraper 20, measured along the second axis A2 between the two end faces 30, is between the internal diameter Di of the circulation duct 15 and twice the internal diameter Di.

The scraper 20 also has a side face 35 delimiting the scraper 20 in a plane perpendicular to the second axis A2. When scraper 20 is substantially cylindrical, the outer diameter is measured between two diametrically opposite points on side face 35.

The scraper 20 comprises, for example, a shell 40 delimiting a chamber 45. In this case, the end faces 30 and the side face 35 are external faces of the shell 40. In particular, the shell 40 comprises two walls of end 46 which separate, along the second axis A2, the chamber 45 from the exterior of the shell 40. In this case, the end faces 30 are faces of the end walls 46.

The end walls 46 are, for example, planar walls perpendicular to the second axis A2.

The shell 40 is, for example, made of polytetrafluoroethylene (PTFE), polyethylene, a polyolefin, polyetheretherketone (PEEK), polyoxymethylene (POM), or even polyamide.

Alternatively, the scraper 20 is solid, that is to say that no chamber 45 is delimited by the shell 40. In this case the scraper 20 will be made of materials having good elastic properties such as an elastomer , in particular a perfluorinated elastomer, resistant to solvents.

The injector 21 is configured to inject a second fluid into the circuit 16, in particular into the circulation conduit 15. For example, the injector 21 is configured to inject into the circulation conduit 15 a flow of second fluid having a controllable flow rate. by injector 21.

The injector 21 is, for example, configured to inject the second fluid into the upstream end 15A of the circulation conduit 15. Alternatively, the injector 21 is configured to inject the second fluid into the downstream end 15B of the circulation conduit. circulation 15, or is configured to inject the second fluid either into the upstream end 15A or into the downstream end 15B.

According to the example of figure 1 , the injector 21 is connected by a valve 47 to the circulation pipe 15.

The second fluid is, for example, a distinct fluid from the first fluid F to be projected. For example, the second fluid is a liquid, sometimes called "cleaning fluid". The liquid is, in particular, a solvent capable of dissolving or diluting the first fluid F. For example, when the first fluid F is a water-based paint, the liquid is water. It should be noted that the type of solvent used is likely to vary, in particular depending on the nature of the first fluid F.

It should also be noted that liquids other than solvents are likely to be used as the second fluid.

As a variant, the second fluid is a first fluid F intended to be sprayed after the first fluid F present in the circulation conduit 15, for example a first fluid F having a different color from the first fluid F present in the circulation conduit 15. According to another variant, the second fluid is a gas such as compressed air.

Many types of injector 21 are likely to be used in the installation 10, depending on the second fluid to be injected. For example, the injector 21 is a gear pump, or even a compressor capable of generating a flow of gas.

It should be noted that, although the injector 21 is described above as being a separate device from the pump 12, it is possible that the role of the injector 21 is fulfilled by the pump 12, for example if the change unit shades 11 comprises a reservoir of second fluid that the pump 12 is then capable of injecting into the conduit 15.

A first example of a method for moving the first fluid F in the installation 10 will now be described.

The process is, for example, a process for cleaning the internal surface 25 of the duct 15. It should be noted that other applications of the process than the cleaning of the duct 15 are possible.

During an initial stage, first fluid F is present in the lumen of circulation conduit 15. For example, the first fluid F partially covers the internal surface of circulation conduit 15.

During a circulation step, the scraper 20 circulates in the circulation conduit 15. For example, the scraper 20 is inserted at one end 15A, 15B of the circulation conduit 15 and propelled to the other end 15A, 15B of the circulation conduit 15 by a flow of second fluid.

The flow of second fluid then exerts on one of the end faces 30 a force tending to propel the scraper in the circulation conduit 15 along the first axis A1.

During the circulation step 20, the first axis A1 and the second axis A2 coincide.

Under the effect of the flow of second fluid, the scraper 20 circulates in the circulation conduit 15. For example, when the flow of second fluid is injected into the upstream end 15A of the conduit 15, the scraper 20 circulates from the upstream downstream. It should be noted that the direction of circulation of the scraper 20 is likely to vary, for example if the flow of second fluid is injected into the downstream end 15B of the conduit 15.

During its circulation, the scraper 20 pushes in front of it the first fluid F present in the circulation conduit 15, thus allowing the recovery of the first fluid F. For example, a valve for recovering the first fluid F opening into the downstream end of the conduit 15 allows the exit of the first fluid F pushed back by the scraper 20. Alternatively, the first fluid F leaves the circulation conduit through the valve 22 of the projection member 13.

The internal surface 25 of the circulation duct 15 is therefore cleaned, since the scraper pushes the first fluid F present on the internal surface 25 of the duct 15 in front of it.

Since the difference between the first value of external diameter De1 of the scraper 20 and the internal diameter Di of the circulation conduit 15 is greater than or equal to 100 μm, the friction between the scraper 20 and the internal surface 25 is limited. The wear of the scraper and of the circulation duct 15 is therefore less than for the installations of the state of the art. However, the first fluid F is effectively collected by the scraper 20.

A difference greater than or equal to 200 μm particularly reduces friction and therefore wear.

In the installation examples mentioned below and their variants, the elements identical to the first example of the picture 2 and the first exemplary moving method are not described again. Only the differences are highlighted.

A second example of installation 10 is represented on the picture 3 .

The installation 10 comprises a holding system configured to prevent a relative translational movement of the scraper 10 with respect to the circulation conduit 15 when the scraper 20 is inserted into the circulation conduit 15, and it is no longer desired that the first fluid F is moved in the circulation conduit 15.

The holding system is configured to cause the scraper 20 to pivot around a pivot axis Ap. The pivot axis Ap is perpendicular to the first axis A1.

More specifically, the holding system is configured to pivot the scraper 20 between a first position in which the first axis A1 and the second axis A2 coincide and a second position in which an angle α between the first axis A1 and the second axis A2 is strictly greater than zero.

The angle α is, for example, greater than or equal to 0.5 degrees (°).

When the scraper 20 is in the second position, as shown in the picture 3 , the scraper 20 is pressed at each of its ends against the internal surface 25 of the circulation duct 15.

Since the scraper 20 has an external diameter De1 strictly less than the internal diameter Di of the circulation conduit 15, the scraper 20 is capable of moving in the circulation conduit 15 without the second fluid F upstream being set in motion, for example under the influence of gravity. This happens in particular each time the spraying is stopped.

Thanks to the holding system, the risk of unwanted movement of the scraper 20 is limited.

According to one embodiment, the holding system comprises a magnet 50 and a magnetic field generator 55.

Magnet 50 is integral with scraper 20. Magnet 50 is, for example, housed in chamber 45.

Magnet 50 is, for example, a permanent magnet, such as a neodymium magnet.

However, embodiments in which the magnet 50 is an electromagnet are also possible.

The magnet 50 has a north pole N and a south pole S. The north N and south S poles of the magnet 50 are aligned along a third axis A3.

The third axis A3 is not confused with the second axis A2. In particular, the third axis A3 forms an angle β with the second axis A2 of the scraper 20.

The angle β is greater than or equal to the angle α between the first axis A1 and the second axis A2. The angle β is greater than or equal to 5°.

The magnetic field generator 55 is configured to generate, in at least a portion of the circulation duct 15, a magnetic field M tending to align the first axis A1 and the third axis A3.

The magnetic field generator 55 is, for example, arranged outside the circulation conduit 15. According to the example shown in the picture 3 , the magnetic field generator is in contact with the outer surface 27 of the circulation conduit 15.

As a variant, the magnetic field generator is included at least partially in the circulation conduit 15. In particular, the magnetic field generator is at least partially comprised between the external surface 27 and the internal surface 25 of the circulation conduit 15.

The magnetic field generator 55 is, for example, an electromagnet comprising a conductive winding surrounding at least a portion of the circulation conduit 15. In this case, when the electromagnet 55 is powered by an electric current, the electromagnet 55 generates in the circulation duct 15 a magnetic field M directed parallel to the first axis A1.

According to the example of picture 3 , the conductive winding is wound around the circulation duct 15, and is therefore in contact with the external surface 27. Alternatively, the conductive winding is likely to be between the external 27 and internal 25 surfaces of the duct 15. Thus, the conductive winding is integrated into the conduit 15.

According to a variant, the magnetic field generator 55 is a permanent magnet. For example, magnetic field generator 55 is a permanent magnet when magnet 50 is an electromagnet.

According to a particular embodiment, the magnetic field generator 55 comprises a permanent magnet and the magnet 50 is a permanent magnet. For example, the permanent magnet of the magnetic field generator 55 is movable relative to the circulation conduit 15 between a first position in which the magnetic field generator 55 generates a negligible magnetic field in a portion of the circulation conduit 15 and a second position in which the magnetic field generator 55 generates in at least a portion of the circulation conduit 15, a magnetic field M tending to align the first axis A1 and the third axis A3

According to another embodiment, the magnetic field generator 55 and the magnet 50 are both electromagnets.

The second exemplary method includes a pivoting step.

The pivoting step is, for example, implemented after the circulation step. In particular, the pivoting step is implemented when the scraper 20 is accommodated in the lumen of the circulation duct 15 but it is desired that the scraper 20 cannot move in translation along the first axis A1 with respect to the circulation conduit 15, for example when the circulation conduit 15 must be moved or when the first axis A1 of the circulation conduit 15 has a component significant vertical and that the scraper 20 would be likely to slide in the circulation duct 15 under the effect of its weight.

During the pivoting step, the scraper 20 pivots from its first position to its second position.

In particular, the electromagnet 55 generates the magnetic field M, which imposes on the scraper 20 a magnetic force tending to align the third axis A3 with the first axis A1. The scraper 20 therefore pivots around the pivot axis Ap up to its second position.

The magnetic force presses the two ends of the scraper 20 against the internal surface 25 of the circulation duct 15, which prevents by friction a translational movement of the scraper along the first axis A1 with respect to the circulation duct 15.

The holding system then makes it possible to hold the scraper 20 in position in a particular portion of the circulation duct 15 despite the reduction in friction between the scraper 20 and the circulation duct 15 due to the difference in the internal and external diameters Di and De1. This immobilization is particularly useful in the event of interruption of the circulation stage before the entire conduit 15 has been traversed by the scraper 20.

A third example of installation 10 is represented on the figure 4 , the installation according to this example and according to the variants of this example not being covered by the text of the claims.

The third example of installation 10 also comprises a holding system configured to prevent a relative translational movement of the scraper 10 with respect to the circulation conduit 15 when the scraper 20 is inserted into the circulation conduit 15.

The holding system is configured to increase the outer diameter of at least a portion of scraper 20 from the first diameter value De1 to a second diameter value De2.

The second diameter value De2 is strictly greater than the first diameter value De1.

In particular, the second diameter value De2 is equal to the internal diameter Di.

The injector 21 is capable of varying the pressure in the circulation conduit 15 when the exit of the first fluid F through the downstream end of the conduit 15 is prevented, for example when the valve 22 of the projection member 13 is closed.

In particular, the injector 21 is configured to vary the pressure in the circulation conduit between a first pressure value and a second pressure value.

The first pressure value is a pressure value typical of the operation of the installation 10 when the scraper 20 circulates in the circulation conduit 15.

The first pressure value is, for example, between 2 bar and 8 bar. Note that the first value may vary.

The second pressure value is strictly greater than the first pressure value. The second pressure value is, for example, greater than or equal to 10 bar. According to one embodiment, the second pressure value is equal to 10 bar, to within 500 millibar.

The scraper 20 is configured to be crushed along the second axis A2 when the pressure in the circulation conduit 15 is greater than or equal to a predetermined pressure threshold.

In other words, the scraper 20 has an uncrushed configuration, shown in the figure 4 and an overwritten configuration shown on the figure 5 . The length L1 of the scraper 20, along the second axis A2, in the non-crushed configuration, is strictly greater than the length L2 of the scraper 20 in the crushed configuration.

The pressure threshold is strictly greater than the first pressure value and strictly less than the second pressure value.

In addition, the scraper 20 is configured so that the crushing of the scraper 20 causes an increase in the external diameter of the scraper 20 from the first value De1 to the second value De2. Thus, in the non-crushed configuration, the outer diameter of scraper 20 has the first diameter value De1 whereas, in the crushed configuration, the outer diameter has the second diameter value De2.

According to one embodiment, in the crushed configuration, the external diameter has a value strictly greater than the internal diameter Di of the circulation duct 15 when the scraper 20 is not accommodated in the circulation duct 15. Thus, when the scraper 20 is accommodated in the circulation duct 15 in the crushed configuration, the external diameter of the scraper 20 has the second diameter value De2 because the external diameter of the scraper 20 is limited by the internal diameter Di. The scraper 20 then exerts against the internal surface 25 of the circulation conduit 15 a frictional force tending to maintain the position of the scraper 20 with respect to the circulation conduit 20.

For example, the shell 40 is made of a flexible polymer material and provided so that a central portion 57 of the shell 40 deforms radially towards the outside of the shell 40 when the end walls 46 are brought closer together. the other.

The flexible polymer material is, for example, chosen from a perfluorinated polymer, Teflon, polyamide and a polyolefin.

According to the example of figures 4 and 5 , the scraper 20 comprises an elastic element 60.

The injector, the shell 40 and the elastic element 60 together form the holding system.

The elastic element 60 is accommodated in the chamber 45 delimited by the shell 40.

The elastic element 60 exerts on the end walls 46 an elastic force tending to move the end walls 46 away from each other. In particular, the elastic element 60 is configured to exert an elastic force having a value strictly greater than a pressure force tending to bring the end walls 46 closer to each other when the pressure in the circulation conduit 15 is less than or equal to the pressure threshold.

The elastic element 60 is, moreover, configured to exert an elastic force having an intensity strictly lower than a pressure force tending to bring the end walls 46 closer to each other when the pressure in the circulation conduit 15 is strictly greater than the pressure threshold.

In other words, the elastic element 60 is configured to maintain the scraper 20 in its non-crushed configuration when the pressure in the circulation conduit 15 is less than or equal to the pressure threshold, and to allow the tilting of the scraper 20 in its crushed configuration when the pressure is strictly greater than the pressure threshold.

The elastic element 60 is, for example, a spring such as a coil spring. It should be noted that other types of elastic elements 60 are likely to be considered.

The operation of the third example will now be described. In particular, a third example of a displacement method implemented by the third example of installation 10 will now be described, this method not being covered by the text of the claims.

During the circulation step, the pressure in the circulation conduit 15 has the first pressure value. The scraper 20 is therefore in its non-crushed configuration.

The third example includes a step of increasing the pressure and a step of crushing.

During the step of increasing the pressure, the injector causes the pressure in the circulation pipe to increase from the first value to the second value. For example, the valve 22 allowing the exit of the first fluid F out of the conduit circulation 15 is closed, and the injector injects the second fluid into the circulation conduit 15 until the second pressure value is reached.

During the crushing step, the scraper 20 tilts into its crushed configuration under the effect of the pressure force exerted on the end walls 46. The crushing causes an increase in the outer diameter of the scraper 20 up to the second diameter value De2.

When the scraper 20 is in its crushed configuration, the scraper 20 exerts a frictional force against the internal surface 25 of the circulation conduit 15, since the external diameter is equal to the internal diameter Di.

The holding system then makes it possible to hold the scraper 20 in position in a particular portion of the circulation conduit 15 when the scraper 20 is crushed, while allowing a reduction in friction between the scraper 20 and the circulation conduit 15 due to the difference internal and external diameters Di and De1 in the non-crushed configuration.

The holding system of the third example does not require additional equipment except the elastic element 60, compared to the first example. In particular, no additional element external to scraper 20 is required. The fluid spraying installation 10 is therefore very simple, and the scraper 20 is capable of being used in fluid spraying installations 10 that already exist.

According to a variant of the third example, the scraper 20 does not include an elastic element 60. The shell 40 includes two end portions 65 and a crushing portion 70.

The two end portions 65 delimit the scraper 20 along the second axis A2. In particular, each end wall 46 is a wall of an end portion 65. This end portion is delimited by the end wall 46 along the second axis 20.

Each end portion 65 is, for example, rigid. In particular, each end portion 65 is configured so as not to be deformed when the scraper 20 passes from the crushed configuration to the non-crushed configuration or vice versa.

The crushing portion 70 is interposed along the second axis A2 between the two end portions 65.

The crushing portion 70 is cylindrical and extends along the second axis A2. The crushing portion 70 therefore has a circular section in a plane perpendicular to the second axis A2.

The crushing portion 70 is configured to exert on the two end portions 65 a force tending to move the two end portions 65 away from each other.

In particular, the crushing portion 70 is configured to exert an elastic force having a value strictly greater than a pressure force tending to bring the two end portions 65 closer to each other when the pressure in the circulation 15 is less than or equal to the pressure threshold.

The crushing portion 70 is, moreover, configured to exert an elastic force having a value strictly lower than a pressure force tending to bring the two end portions 65 closer to each other when the pressure in the conduit circulation 15 is strictly greater than the pressure threshold.

In other words, the crushing portion 70 is configured to maintain the scraper 20 in its non-crushed configuration when the pressure in the circulation conduit 15 is less than or equal to the pressure threshold, and to allow the tilting of the scraper 20 in its crushed configuration when the pressure is strictly greater than the pressure threshold.

The crushing portion 70 is, for example, made of an elastomeric material. In this sense, the portion 70 can be qualified as an elastomeric portion.

The crushing portion 70 is configured to deform radially towards the outside of the shell 40 when the two end portions 65 are moved closer to each other, as visible on the figure 6 .

A fourth example of installation 10 will now be described. Neither the installation nor the method according to this example being not covered by the text of the claims.

The scraper 20 includes a ferromagnetic element.

Ferromagnetism designates the ability of certain bodies to become magnetized under the effect of an external magnetic field and to retain part of this magnetization.

The ferromagnetic element is, in particular, secured to the shell 40.

The ferromagnetic element is, for example, received in chamber 45.

Installation 10 includes a magnetic field generator 55.

The magnetic field generator 55 is, for example, similar to the magnetic field generators 55 used in the second example previously described.

The magnetic field generator 55 is configured to generate, in at least a portion of the circulation conduit 15, a magnetic field tending to bring the ferromagnetic element closer to the magnetic field generator 55.

For example, the magnetic field generator 55 is a magnet generating a magnetic field capable of attracting the ferromagnetic element towards the magnet.

The method then comprises an attraction step replacing for example the pivoting step.

During the attraction step, the magnetic field generator 55 generates the magnetic field in the corresponding portion of the circulation conduit 15. For example, when the magnetic field generator 55 is a permanent magnet, the magnetic field generator 55 is approached to the portion of the circulation duct 15 in which it is desired that the scraper 20 is maintained.

Under the effect of the magnetic field, the ferromagnetic element is attracted towards the magnetic field generator 55. Consequently, the scraper 20 is moved in the conduit 15 until it comes into contact with the internal surface 25 of the conduit 15. particular, the scraper 20 is pressed against the internal surface 25.

The scraper 20 is then held in position in the portion of the duct 15 by the effect of the magnetic field which presses the scraper against the internal surface 25.

The fourth example of installation 10 is particularly simple to implement.

A method for spraying a first fluid F will now be described.

The projection method is, for example, implemented by a projection installation 10 conforming to one of the examples of projection installation 10 described above. Only the process according to the second example and according to the variants of this second example is covered by the text of the claims.

However, it should be noted that the spraying process is capable of being implemented by other types of fluid spraying installations, in particular fluid spraying installations in which the difference between the internal diameter Di of the conduit of circulation 15 and the first value De1 is strictly less than 100 micrometers, for example equal to zero. In the case where the first value De1 is strictly less than 100 μm, neither the corresponding installation nor the corresponding method are covered by the text of the claims.

The method includes a first projection step, a circulation step, a return step and a second projection step.

During the first projection step, a first fluid F is projected by the projection installation 10. In particular, the first fluid F is injected by the pump 12 into the circulation conduit 15 and transmitted by the circulation conduit 15 to 'to the projection member 13 which projects the first fluid F.

The first fluid F is, for example, projected onto an area of an object, a structure or an installation that it is desired to cover with the first fluid F.

The first fluid F projected during the first projection step has, for example, a first shade.

The first projection step includes determining a first volume of first fluid F. The first volume is the volume of first fluid F that has been projected since the start of the first projection step.

The first volume is, for example, determined by knowing the flow rate of the pump 12 and the total operating time of the pump 12 since the start of the first spraying step.

The first projection step is implemented until a difference between a total volume of first fluid F to be projected and the first volume is equal to a second predetermined volume.

The total volume is, for example, the total volume of first fluid F to be projected by the installation 10 to make it possible to cover with the first fluid F a predetermined object, or even a predetermined zone of an object, a structure or a 'an installation.

The second volume is the volume of first fluid F that the scraper 20 is able to move during the circulation step. For example, the second volume is determined experimentally by filling the circulation conduit 15 with first fluid F and by implementing the circulation step.

The second volume is, for example, greater than or equal to 80 percent (%) of the volume of the lumen of the circulation conduit 15

The second volume is, for example, the volume of first fluid F contained in the circulation conduit 15. In particular, the second volume is the volume of the lumen of the circulation conduit 15.

In other words, the first projection step is implemented until the volume of first fluid F which is contained in the circulation conduit 15 and which is capable of being pushed back to the projection member 13 by the scraper 20 is sufficient to cover with first fluid F the zones of the object, of the structure or of the installation which it is desired to cover with the first fluid F but which have not yet been covered.

The circulation step is implemented after the first projection step.

During the circulation step, the scraper 20 is introduced into the circulation conduit 15, for example at the upstream end 15A of the circulation conduit 15, and the injector 21 injects the second fluid upstream of the scraper 20.

The second fluid used during the circulation step is, for example, a liquid, in particular a solvent suitable for dissolving or diluting the first fluid F.

During the circulation step, the valve 22 is open.

The scraper 20 circulates from upstream to downstream in the circulation conduit 15, under the effect of the second fluid injected into the upstream end 15A by the injector 21. For example, the scraper 20 traverses a length of the conduit circulation 15 greater than or equal to half of a total length of the circulation conduit 15, in particular greater than or equal to 90% of the total length.

The scraper 20 pushes back part of the first fluid F present in the circulation conduit 15 as far as the projection member 13, in particular as far as the sprayer head 23.

During the circulation step, the second volume of first fluid F is pushed by the scraper 20 to the sprayer head 23. In other words, during the circulation step, the volume of first fluid F flowing through valve 22 is equal to the second volume.

The first fluid F pushed by the scraper 20 up to the sprayer head 23 is projected by the sprayer head 23.

The return step is implemented after the circulation step.

During the return step, the injector 21 injects the second fluid into the circulation conduit 15 downstream of the scraper 20. The second fluid then pushes the scraper 20, which moves upstream in the circulation conduit.

For example, the valve 17 is open to allow the second fluid to leave the circulation conduit 15 upstream of the scraper 20.

At the end of the return step, the scraper 20 is removed from the circulation conduit 15.

The return stage is followed by the second projection stage.

The second spraying step is identical to the first spraying step except for the first sprayed fluid F. In particular, during the second projection step, the first fluid F injected by the pump 12 into the circulation conduit 15 and projected by the projection member 13 is a first fluid F different from the first fluid F which is injected by the pump 12 during the first projection step. In particular, the first fluid F projected during the second projection step has a color different from the color of the first fluid F projected during the first projection step.

The projection method allows the use of a large part of the first fluid F which is present in the circulation conduit 15 thanks to the use of the scraper 20 to push this first fluid F back to the projection member 13. The spraying process therefore has a better yield in terms of quantity of fluid consumed than other spraying processes, in which part of the fluid consumed remains in the circulation conduit 15 at the end of the spraying, and is not effectively recovered.

When the second fluid is a liquid, the control of the second volume of projected fluid is improved, since the liquids are weakly compressible.

When this liquid is a solvent, the first fluid F remaining in the circulation pipe 15 after the passage of the scraper 20, in particular the first fluid F capable of partially covering the internal surface 25, is dissolved or diluted by the solvent and extracted from the pipe. 15 with the solvent. The duct 15 is therefore partly cleaned, and the risks of contamination of the first fluid F sprayed during the second spraying step by the first fluid F sprayed during the first spraying step are limited.

The cleaning of the duct 15 is further improved when the return step is implemented using this solvent used as the second fluid, since the circulation duct 15 is then cleaned twice by the solvent, during the circulations of the scraper downstream and then upstream.

When the scraper 20 conforms to the scrapers 20 described in the first, second, third and fourth preceding examples, that is to say when a difference between the internal diameter Di of the circulation duct 15 and the first value De1 is greater or equal to 100 micrometers (μm), the scraper 20 circulates easily even in the portions of the circulation duct 15 which are not rectilinear, in particular in the second portion 29, which is helical. The quantity of first fluid F recovered is then increased, since it is avoided that a section of the conduit 15, which cannot be traversed by the scraper 20, is still filled with first fluid F at the end of the circulation step. .

In the case where the first value De1 is strictly less than 100 μm, neither the corresponding installation nor the corresponding method are covered by the text of the claims.

The use of a second helical portion 29 makes it possible to avoid the formation, in the first fluid F contained in the second portion 29, of conductive bonds under the effect of the electric fields frequently used for the projection of the first fluid F when the first fluid F contains electrically conductive particles. The scrapers 20 according to the first, second, third and fourth examples are therefore particularly advantageous for these applications.

A fifth example of installation 10 will now be described.

The elements identical to the first installation example 10 are not described again. Only the differences are highlighted.

However, it should be noted that, in the fifth example of installation 10, the difference between the internal diameter Di of the circulation duct 15 and the first value De1 is likely to vary, in particular to be strictly less than 100 μm, by example equal to zero, or else to be greater than or equal to 100 μm as is the case in the first example. In the case where the first value De1 is strictly less than 100 μm, neither the corresponding installation nor the corresponding method are covered by the text of the claims.

When this difference is greater than or equal to 100 μm, the fifth installation example 10 is capable of comprising a scraper 20 and a holding system 55 conforming to the scrapers 20 and to the holding systems of the second, third and fourth installation examples. 10 and previously described variants of these second, third and fourth examples, only the installation and the method according to the second example and according to the variants of this second example being covered by the text of the claims.

According to a variant not covered by the text of the claims, the fifth example of installation 10 does not include a scraper 20.

The injector 21 is configured to inject the second fluid into at least one of the color changer block 11, the pump 12, the circulation conduit 15 and the projection member 13. According to the embodiment shown in the figure 7 , the injector 21 is connected to the color changer block 11 by a valve 105, to the pump 12 by a valve 110, to the circulation pipe 15 by the valve 47 and to the projection member 13 by a valve 115.

The second fluid is then a liquid, for example a liquid solvent capable of dissolving or diluting the first fluid F, or even water.

The injector 21 is configured to inject a predetermined volume of second fluid into the circuit 16. The injector 21 is furthermore configured to stop the injection when the volume injected is equal to a predetermined volume.

For example, the injector 21 is configured to estimate a value of a total volume of second fluid injected into the circuit 16 since the start of the injection, and to stop the injection when the total volume is equal to the predetermined volume.

According to one embodiment, the injector 21 comprises a control module such as a data processing unit or even a dedicated integrated circuit, suitable for estimating the total volume injected and for controlling the injection of the second fluid by the injector 21, for example suitable for controlling the opening or closing of the valves 47, 105, 110, 115. The predetermined volume is chosen according to the quantity of second fluid which it is desired to inject into the circuit 16. The volume predetermined is therefore likely to vary.

Examples of injectors 21 capable of being used in the fifth example are described below.

The injector 21 is furthermore configured to inject a flow of gas into the circuit 16. In particular, the injector 21 is configured to inject the predetermined volume of second fluid into the circuit 16, and to then inject the gas into the circuit 16 to cause the displacement of the second fluid in the circuit 16.

For example, the injector 21 is connected to a source of pressurized gas.

The gas is, for example, compressed air.

The gas has a third pressure value when the gas is injected into the circuit 16. The third pressure value is less than or equal to 20 bar.

The fifth example of installation 10 is suitable for implementing a method comprising a step of injecting the second fluid into the circuit 16.

For example, during the injection step, the second fluid is injected into the circulation conduit 15.

As a variant, the second fluid is injected into at least one of the color changer unit 11, the pump 12, the circulation conduit 15 and the projection member 13.

During the injection step, the injector 21 estimates the volume of second fluid injected since the start of the injection step. For example, the injector 21 periodically estimates the volume of second fluid injected since the start of the injection step. According to one embodiment, the injector 21 estimates the volume of second fluid injected with a period less than or equal to 100 milliseconds.

The estimated volume is compared by the injector 21 to the predetermined volume.

If the estimated volume of second fluid is strictly less than the predetermined volume, the injector 21 continues the injection of the second fluid into the circuit 16.

If the estimated volume is equal to or greater than the predetermined volume, the injector 21 stops the injection. For example, injector 21 forms the valve or valves 47, 105, 110 and 115 which connect injector 21 to circuit 16.

According to the example shown in the figure 7 , the injector 21 comprises a cylinder 75, a piston 80, an actuator 85 and a valve 90.

Cylinder 75 is configured to contain the second fluid. For example, the cylinder 75 delimits a cylindrical cavity capable of receiving the second fluid.

Cylinder 75 extends along an axis Ac specific to cylinder 75.

It should be noted that the cylinder 75 is likely to have a circular base, but also a polygonal base, or even a base having any shape in a plane perpendicular to the axis Ac of the cylinder 75.

The cylinder 75 is, for example, made of a metallic material such as stainless steel or aluminum. The cavity delimited by cylinder 75 has an interior volume of between 50 cubic centimeters (cc) and 1000 cc.

The piston 80 is accommodated in the cavity delimited by the cylinder 75. The piston 80 separates the cavity delimited by the cylinder 75 into two chambers 95, 100 of variable volume.

The piston 80 is cylindrical, for example delimited by a peripheral face complementary to an internal face of the cylinder 75 and by two faces perpendicular to the axis of the cylinder 75.

The piston 80 is, for example, made of a metallic material. According to one embodiment, the face of the piston 80 which delimits the chamber 100 is made of stainless steel. As a variant, this face is made of a polymer, or even covered with a layer of polymer or with a layer of polytetrafluoroethylene (PTFE).

The piston 80 is movable in translation between a primary position and a secondary position relative to the cylinder 75 so as to vary the respective volumes of the chambers 95 and 100. In particular, the piston 80 is movable along the axis Ac of the cylinder 75 .

The primary position is the position in which the volume of chamber 100 is greatest. When the piston 80 is in the primary position, the volume of the chamber 95 is, for example, equal to zero.

The secondary position is the position in which the volume of the chamber 100 is the smallest. For example, when piston 80 is in the secondary position, piston 80 bears against an end wall of cylinder 75, so that the volume of chamber 100 is zero.

The piston 80 is configured to prevent the passage of second fluid between the chambers 95, 100 that it delimits. For example, the piston 80 carries sealing means such as a seal surrounding the piston 80 in a plane perpendicular to the axis of the cylinder 75.

Chamber 100 is configured to be at least partially filled with second fluid. For example, chamber 100 is connected by valve 90 to a source of second fluid such as a reservoir.

The chamber 100 is able to be connected, for example by the valve 47, to the circulation pipe 15. According to the example of the figure 7 , the chamber 100 is capable of being connected to the upstream end 15A of the circulation duct. As a variant, the chamber 100 is able to be connected to the downstream end 15B, or even to the two ends 15A, 15B.

Actuator 85 is configured to move piston 80 between its primary and secondary positions. The actuator 85 comprises, for example, a motor and a rod capable of transmitting a force from the motor to the piston 80 to move the piston 80.

The actuator 85 is, in particular, configured to determine a position of the piston 80 relative to the cylinder 75, and to control or stop a movement of the piston 80 according to the determined position. Many types of actuators 85 allow such determination of the position of the piston.

The motor is, for example, an electric motor such as a torque motor, or even a brushless motor.

According to one embodiment, the motor is a servomotor, that is to say a position-controlled motor. For example, the motor is controlled so as to maintain the piston 80 in a predetermined position relative to the cylinder 75, the predetermined position being liable to vary.

As a variant, the motor is replaced by a pneumatic or hydraulic member capable of moving the piston 80, for example a pump capable of injecting a liquid into the chamber 95 to move the piston.

The actuator 85 is, in particular, configured to impose on the second fluid a pressure greater than or equal to the third pressure value. For example, a pressure sensor is integrated in the chamber 100, and the control module is capable of controlling an increase in the force exerted by the actuator on the piston 80 until the pressure of the second fluid in the chamber 100 is greater than or equal to the third pressure value.

As a variant, the actuator 85 is configured to estimate the pressure of the fluid in the chamber 100 from values of an electric current supplying the electric motor of the actuator 85.

During the injection step, chamber 100 contains second fluid and actuator 85 moves piston 80 towards the secondary position. For example, during the injection step, the chamber 100 is filled with the second fluid.

Under the effect of the movement of the piston 80, the second fluid is injected into the circulation conduit 15.

Actuator 85 periodically determines a position of piston 80 in cylinder 75, in particular a distance traveled by piston 80 along the axis of cylinder 75 from the primary position. The determination of the distance traveled is equivalent to the determination of the volume injected, since the volume injected is a one-to-one function of the distance traveled, i.e. to a distance traveled corresponds a single volume injected.

Alternatively, actuator 85 compares the total volume injected with the predetermined volume by determining whether or not piston 80 has reached a predetermined position corresponding to the predetermined volume.

The predetermined position is, in particular, a position such that the displacement of the piston from the primary position to the secondary position decreases the volume of the chamber 100 by a volume value equal to the predetermined volume.

The injector 21 is furthermore configured to stop the injection when the volume injected is equal to a predetermined volume.

For example, if piston 80 has not reached the predetermined position, actuator 85 continues to move piston 80 to the secondary position.

If piston 80 is in the predetermined position, actuator 85 stops moving piston 80.

Alternatively, injector 21 is configured to close valve 47 when piston 80 reaches the predetermined position. It should be noted that other types of injectors 21 are likely to be used in the fifth example.

For example, the injector 21 comprises a source of second fluid and a flow meter.

The source of second fluid is, for example, a reserve of second fluid under a pressure greater than or equal to the third pressure value, or even a pump suitable for generating a flow of second fluid, such as a gear pump or even a peristaltic pump.

The injector 21 comprises, for example, a pressure sensor located in particular in the outlet duct of the source of second fluid, and capable of measuring the pressure of the second fluid at the outlet of the source.

The flowmeter is able to measure values of the flow rate of second fluid injected by the injector 21 into the circuit 16.

The flow rate is, for example, a volume flow rate. Alternatively, the flow rate is a mass flow rate.

The injector 21 is configured to estimate, from the measured flow rate values, the total volume of second fluid injected into the circuit from the start of the injection step. For example, the injector 21 estimates the total volume injected by temporal integration of the measured flow rate values.

The injector 21 interrupts the injection when the total volume is equal to the predetermined volume. For example, injector 21 closes valves 47, 105, 110, 15 connecting injector 21 to circuit 16.

The injection step is, for example, implemented during a circulation step as defined previously. In this case, the scraper 20 circulates from upstream to downstream in the circulation conduit 15 under the effect of the second fluid injected.

As a variant or in addition, the injection step is implemented during the return step to propel the scraper 20 from downstream to upstream.

The fifth example of installation 10 is in particular capable of implementing the projection method described above, as well as other projection methods.

For example, the fifth example of installation 10 is suitable for implementing a spraying process not covered by the text of the claims, in which, during the circulation step, no scraper 20 is present in the conduit 15 In this case, during the circulation step, the second fluid pushes the first fluid F in front of it as far as the projection member 13.

According to other possible variants, the injection step is implemented during a cleaning process for at least one of the color changer block 11, the pump 12 and the projection member 13.

The use of an injector 21 capable of stopping the injection of second fluid when the volume of second fluid injected is equal to a predetermined volume makes it possible to precisely control the quantity of second fluid used during the injection step. In particular, this volume does not depend on the viscosity of the first fluid F (or of the mixture between the first fluid F and the second fluid) present in the circuit 16, unlike the methods of the state of the art in which a source of second fluid is connected to the circuit 16 for a predetermined time, since the viscosity of the fluid or fluids contained in the circuit depends among other things on the ratio between the first fluid F and the second fluid present in the circuit 16.

This is particularly advantageous during a circulation step comprising the projection of the first fluid F pushed back by the scraper 20 or by the second fluid, since the volume of first fluid F projected is then well controlled.

The use of a piston 80 to inject the second fluid into the circulation conduit 15 makes it possible in particular to more precisely control the volume of second fluid injected, in particular when this fluid is a liquid such as a solvent, than is possible. the injectors 21 of the state of the art. The injectors of the state of the art which use pumps such as gear pumps have a flow rate liable to vary according to the average viscosity. For example, gear pumps have internal leaks that are a function of this viscosity. Therefore, the volume of liquid actually injected into the circulation conduit F by the injectors of the state of the art is not effectively controlled. On the contrary, the piston 80, by its movement, makes it possible to impose a volume of propulsion liquid actually injected, since this volume depends solely on the variation in volume of the chamber 100. The fifth example of installation 10 therefore allows a better control of the quantity of second fluid injected.

Estimating the volume of second fluid injected from the distance traveled by the piston 80 is a method for precisely and simply estimating the amount of volume injected into a device other than the cylinder 75, the piston 80 and the actuator 85 is required.

Injectors 21 estimating the volume of second fluid actually injected from the measured flow rate values also allow better control of the quantity of second fluid injected.

The injection of the second fluid with a pressure greater than or equal to the pressure of the gas makes it possible to use the gas to propel the second fluid, and therefore reduces the quantity of second fluid necessary.

Estimating this pressure from the electrical current consumed eliminates the need for a sensor, and therefore simplifies the installation 10.

A sixth example of installation 10 will now be described. Neither the installation nor the method according to this example being not covered by the text of the claims.

The sixth example differs from the second example in that the holding system of the sixth example comprises the magnet 50 and at least one ferromagnetic element 56.

The magnet 50 is, in particular, a permanent magnet.

Magnet 50 is configured to generate a magnetic field capable of generating a force having a value between 1 newton (N) and 10 N, as will appear below.

In this variant, the third axis A3 is, for example, merged with the second axis A2. However, embodiments in which the axes A2 and A3 do not coincide are also possible. In general, the orientation of the third axis A3 with respect to the second axis A2 of the scraper 20 is liable to vary.

Each ferromagnetic element 56 is made of a ferromagnetic material, in particular a soft ferromagnetic material.

Ferromagnetism designates the ability of certain bodies to become magnetized under the effect of an external magnetic field and to retain part of this magnetization when the magnetic field is interrupted.

Iron, nickel, chromium dioxide, gadolinium and some steels are examples of ferromagnetic materials.

As a variant, the ferromagnetic material is a steel, for example an iron-rich steel. For example, a surface treatment of the steel making up the ferromagnetic element 56 is provided to protect the ferromagnetic element from corrosion.

Each ferromagnetic element 56 is arranged close to at least a portion of the circulation duct 15 so that the magnet 50 is attracted by the ferromagnetic element 56 when the scraper 20 is accommodated in said portion of the circulation duct 15 .

The ferromagnetic element 56 is, for example, in contact with the outer surface 27 of at least a portion of the duct 15. Alternatively, the ferromagnetic element 56 is included at least partially in the circulation duct 15. In particular, the ferromagnetic element 56 is at least partially included between the outer surface 27 and the inner surface 25 of the circulation conduit 15.

According to one embodiment, the ferromagnetic element 56 or the ferromagnetic elements 56 extend(s) along the circulation conduit 15 over an extension length greater than or equal to half the length of the circulation conduit 35. For example, the extension length is greater than or equal to three quarters of the length of the circulation conduit 15, in particular greater than or equal to 90 percent (%) of the length of the circulation conduit 15.

Each ferromagnetic element 56 is, for example, a wire, a sheet, a chain, or even a block of ferromagnetic material.

The holding system comprises, for example, a single ferromagnetic element 56 extending over the extension length along the circulation conduit 15. Alternatively, when the holding system comprises a plurality of ferromagnetic elements 56, these elements ferromagnetic elements 56 are for example arranged successively along the circulation duct 15, in which case the extension length is measured between the ends of the ferromagnetic elements 56 furthest apart from each other. A distance between two successive ferromagnetic elements is, for example, between 0.5 millimeters (mm) and 5 mm.

When the holding system comprises a single ferromagnetic element 56, the extension length is measured between two ends of the ferromagnetic element 56.

The ferromagnetic element 56 is, for example, a wire or a chain extending along the conduit 15 over the extension length. The thread or the warp is, for example, a straight thread.

As a variant, when the holding system comprises a single ferromagnetic element 56, the single ferromagnetic element 56 surrounds, for example, the circulation conduit 15 in a plane perpendicular to the first axis A1.

For example, the ferromagnetic element 56 is a sheet applied to the outer surface 27.

As a variant, the ferromagnetic element 56 is a longitudinal ferromagnetic element 56, such as a wire, a cable or a chain, wound around the circulation conduit 15, for example extending along a helix, in particular a circular helix.

A helix is a curve whose tangent at each point makes a constant angle with a given direction, this direction being in particular the first axis A1.

A radius is defined for the helix. The radius is between 4 mm and 18 mm.

A pitch is defined for the propeller. The pitch is, in particular, defined as being the distance between two points of the helix delimiting a portion of the helix corresponding to a complete turn around the first axis A1. The pitch is between 0.5 mm and 5 mm.

As an optional addition, the installation 10 further comprises a cylindrical sheath, for example made of an elastomeric material, of polyamide, or of Teflon.

Each ferromagnetic element 56 is interposed between the circulation duct 15 and the sheath. The sheath is in particular configured to press each ferromagnetic element 56 against the external surface 27 of the circulation conduit 15. For example, the sheath has an internal diameter equal to the external diameter of the circulation conduit 15.

The sheath is, for example, a tight sheath configured to prevent a liquid from reaching each ferromagnetic element 56.

The sheath has a thickness comprised, for example, between 0.5 mm and 1.5 mm.

This thickness and the inside diameter of the sheath are likely to vary.

The magnet 50 and the ferromagnetic element 56 are in particular configured to exert on the scraper 20, when the scraper 20 is received in the circulation conduit 15, a force comprised between 1 N and 10 N so as to maintain the scraper 20 in position in the circulation duct 15.

In particular, when the scraper 20 is inserted into the circulation duct 15, a distance, measured in a direction perpendicular to the first axis A1 between the ferromagnetic element 56 and the magnet 50 is between 0.5 mm and 3 mm.

When the ferromagnetic element 56 is a cable or a wire, a diameter of the wire or the cable is, for example, between 0.4 mm and 2 mm.

Thanks to the magnet 50 and the ferromagnetic element 56 or the ferromagnetic elements 56, when the flow of second fluid is interrupted, for example during a pause in the projection, the magnet 50 and the ferromagnetic element 56 exert on the scraper 20 a force tending to press the scraper 20 against the internal surface 25, for example by pivoting the scraper 20 or quite simply via the bringing together of the magnet 50 and the ferromagnetic element 56, as represented diagrammatically on the figure 8 . Thus, the scraper 20 is held in position in the conduit 15 even in the absence of flow of the second fluid. Furthermore, it is not necessary to provide any additional member, in particular an active member such as an electromagnet or a moving member, to hold the scraper 20 in position.

On the contrary, when the flow of second fluid circulates in the conduit 15, this flow propels the scraper 20 along the conduit despite the presence of the holding system. The installation 10 therefore has a simplified operation since it is not necessary to activate the holding system, the interruption of the flow of second fluid being sufficient to cause the scraper 20 to be held in position.

Furthermore, the scraper 20 can thus be held in position at any point of the conduit 15 between the ends of the ferromagnetic element(s) between which the extension length is measured. The cleaning process is therefore simplified, since it is not necessary for the scraper 20 to be in a precise position to enable it to be held. This is all the more interesting when the extension length is greater than or equal to half the length of the conduit 15.

The use of a ferromagnetic element 56 wound around the pipe 15 makes it possible in particular to ensure good flexibility of the assembly formed by the pipe 15 and the ferromagnetic element 56 while ensuring good connection of these two elements even during deformations of the conduit 15. Such a ferromagnetic element 56 is therefore particularly suitable for applications in which the projection member 13 is mobile, in particular when this member 13 is mounted on a movable arm, since significant deformations of the conduit 15 are frequent in level of the wrist of the robotic arm.

The use of a sheath makes it possible, here too, to ensure good attachment of the ferromagnetic element(s) 56 and the circulation conduit 15, without compromising the flexibility of the latter, and to protect each ferromagnetic element 56 against corrosion.

Claims (5)

1. A fluid spraying facility (10) comprising a fluid circulation pipe (15) and a scraper (20) that can circulate in the pipe (15), the scraper (20) being configured to push back in front of it fluid present in the pipe (15) when the scraper circulates in the pipe (15), the pipe (15) and the scraper (20) each having a circular section, the pipe (15) having an inner diameter (Di), the scraper (20) having an outer diameter, the outer diameter having a first value (De1),

   wherein a difference between the inner diameter (Di) of the pipe and the first value of the outer diameter (De1) of the scraper (20) is greater than or equal to 100 micrometers, preferably greater than or equal to 200 micrometers.

   the facility comprising a holding system capable of preventing a relative translational movement of the scraper (20) with respect to the pipe (15) when the scraper (20) is inserted in the pipe (15), the pipe (15) extending along a first axis (A1), the scraper (20) extending along a second axis (A2) and being configured to circulate in translation relative to the pipe (15) along the first axis (A1) when the first axis (A1) and the second axis (A2) are merged, the holding system being configured to rotate the scraper (20) around an axis (Ap) perpendicular to the first axis (A1) such that an angle (α) between the first axis (A1) and the second axis (A2) is strictly greater than zero, preferably greater than or equal to 0.5 degrees.
2. The fluid spraying facility according to claim 1, wherein the scraper (20) comprises a magnet (50) having a north pole (N) and a south pole (S), the poles (N, S) of the magnet (50) being aligned along a third axis (A3), an angle (β) between the second axis (A2) and the third axis (A3) being strictly greater than zero, preferably greater than or equal to 5 degrees, the holding system comprising a magnetic field generator (55) capable of generating in at least a portion of the pipe (15) a magnetic field intended to align the third axis (A3) and the first axis (A1).
3. The fluid spraying facility according to claim 2, wherein the magnetic field generator (55) is in contact with an outer surface (27) of the circulation pipe (15).
4. The fluid spraying facility according to claim 2, wherein the magnetic field generator (55) is at least partially located between an inner surface (25) and an outer surface (27) of the circulation pipe (15).
5. A method for moving a fluid in a fluid spraying facility (10) comprising a fluid circulation pipe (15), comprising a step of a scraper (20) circulating in the pipe (15), the scraper (20) pushing back in front of it fluid present in the pipe (15) during the circulation step, the pipe (15) and the scraper (20) each having a cylindrical section, the pipe (15) having an inner diameter (Di), the scraper (20) having an outer diameter, the outer diameter having a first value (De1) during the circulation step,

   a difference between the inner diameter (Di) of the pipe (15) and the first outer diameter value (De1) of the scraper (20) being greater than or equal to 100 micrometers, preferably greater than or equal to 200 micrometers, wherein the pipe (15) extends along a first axis (A1), the scraper (20) extending along a second axis (A2) and being configured to circulate in translation relative to the pipe (15) along the first axis (A1) when the first axis (A1) and the second axis (A2) are merged,

   the method comprising a pivoting step, by a holding system capable of preventing a relative translation movement of the scraper (20) with respect to the pipe (15) when the scraper (20) is inserted in the pipe (15), of the scraper (20) around an axis (Ap) perpendicular to the first axis (A1) such that an angle (α) between the first axis (A1) and the second axis (A2) is strictly greater than zero, preferably greater than or equal to 0.5 degrees.

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