EP2985386B1

EP2985386B1 - Spraying device for spraying a liquid product onto a paper web

Info

Publication number: EP2985386B1
Application number: EP15002387.7A
Authority: EP
Inventors: François Rodriguez
Original assignee: Blanch Andreu Xavier
Current assignee: Blanch Andreu Xavier
Priority date: 2014-08-11
Filing date: 2015-08-11
Publication date: 2017-04-05
Anticipated expiration: 2035-08-11
Also published as: ES2632140T3; EP2985385A1; EP2985386A1

Description

Technical Field

The present invention relates to a spraying device for spraying a liquid product onto a paper web useful for applying a coating of liquid product sprayed onto a moving paper web.
The device of the present invention is useful for creating a barrier coating against fats, oil and water, and/or an anti-scratch coating, and/or a pigmentation coating, and/or a coating of any other surface treatment on a paper web, whereby obtaining a waterproof paper web which can be used, for example, in forming hydrophobic corrugated cardboard, or a paper web with other properties and for other uses.

Background of the Invention

Document WO 2013167771 A1 discloses an applicator device for applying a liquid product on a paper comprising a spray chamber with an opening facing the path of a moving paper web. The spray chamber has a front wall, a rear wall, side walls, and a base opposite the opening. A plurality of spraying nozzles is installed inside the spray chamber and said nozzles are connected to a liquid product supply source and oriented so as to direct the sprayed liquid product towards the opening across the spray chamber in order to spray the liquid product onto a surface of the moving paper web.
A drawback of the device described in the cited document WO 2013167771 A1 is that part of the sprayed liquid product is deposited and accumulated on the inner surfaces of the walls of the spray chamber, making frequent cleaning operations necessary.
Document WO 0042254 A1 describes an applicator apparatus for applying a liquid product on a paper or cardboard web comprising a spray chamber envisaged for being installed in a paper web manufacturing line. The spray chamber is formed by a plurality of walls and a plurality of spraying nozzles is installed therein, with the mentioned drawback associated with the unwanted deposition and accumulation of liquid product on the walls of the spray chamber.
Document WO 2006079678 A1 discloses an applicator device for applying a liquid product on a paper sheet including a plurality of spraying nozzles installed such that they are rotational so as to regulate the angle of incidence of the sprayed liquid product with respect to the paper sheet, and a system for adapting the width of the device to the width of the paper sheet.
Document EP 2146003 A2 describes a device for applying a liquid product curtain as a coating on a paper sheet including a suction nozzle for absorbing part of the liquid product that is sprayed and not deposited on the paper sheet.
Other examples of apparatuses for applying a liquid product on a paper sheet are described in documents DE 102008040419 A1 and WO 2005040497 A1 .
Document JP 201200047 6A discloses a method of manufacturing lotion paper by which a ply made of a plurality of layered base paper webs is temporarily divided into two base paper webs, a liquid is attached to the divided two base paper webs from the inner side of the ply, and the base paper webs to which the first liquid is attached are layered on each other again to make the ply. The moving base paper webs are guided by guide rollers and the liquid is sprayed onto a seaming portion of the two moving base paper webs by means of a plurality of spraying nozzles arranged on a support located between the two base paper webs inside a spray chamber. The spray chamber is delimited by several contiguous sections of the two base paper webs, and by side walls perpendicular to the axes of the guide rollers. Each of the sections of the base paper webs is defined between two of the guide rollers.
Document DE 102008021541 A1 discloses a method for applying a treatment agent to a surface of a paper web (4). The paper web to be treated (4) is passed through an entrance slit (7) in an application chamber (5) having spray nozzles (6). The treating agent is applied through the spray nozzles (6) on at least one side of the paper web (4). The paper web (4) treated with the treatment agent is guided through a press nip between two rotating press rolls (3). The application chamber (5) is delimited by several walls and at least one of the rotating press rolls (3) forms part of the walls of the application chamber (5).

Disclosure of the Invention

The present invention contributes to mitigate the foregoing and other drawbacks by providing a spraying device for spraying a liquid product onto a paper web comprising a spray chamber delimited to a large extent by a moving paper web guided by parallel guide rollers, and a plurality of spraying nozzles connected to a liquid product supply source and arranged inside said spray chamber to spray said liquid product onto said moving paper web.
Preferably, the spray chamber is delimited, at least in part, by a support on which said spraying nozzles are arranged and by at least two contiguous sections of the paper web, wherein each of said sections of the paper web is defined between two of said guide rollers and, wherein one of said contiguous sections of the paper web faces directly the spraying nozzles. The two contiguous sections of the paper web therefore together form an angle containing, including or encompassing the spraying nozzles.
Optionally, the guide rollers can define more than two sections of the paper web delimiting the spray chamber, with one or more guide rollers located inside the spray chamber. The spraying nozzles are preferably arranged so as to direct the sprayed liquid product towards a single section of the paper web.
The plurality of sections of the paper web delimiting the spray chamber contribute to minimizing the area of other surfaces of the spray chamber exposed to the liquid product sprayed by the spraying nozzles, and therefore the drawback of the unwanted deposition and accumulation of liquid product on surfaces other than the paper web is minimized.
Regardless of the number of sections of the paper web in the spray chamber, the spray chamber is further delimited by side walls perpendicular to the axes of the guide rollers. These side walls are movable along guides associated with a structure of the device in a direction parallel to the axes of the guide rollers and can be fixed in desired positions along said guides to adjust the width of the spray chamber to the width of the paper web.
In one embodiment, the support on which the spraying nozzles are arranged is a rotary support which can be rotated with respect to a rotation axis parallel to the axes of the guide rollers to regulate the spraying angle of the spraying nozzles, i.e., the angle of the spraying nozzles with respect to the section of the paper web towards which they are directed. Preferably, this rotary support includes a tubular wall defining an enclosure in which the spraying nozzles are installed. The tubular wall rotates together with the rotary support and has at least one longitudinal opening through which the liquid product is sprayed into the spray chamber by the spraying nozzles.
In one embodiment, the spraying nozzles are arranged on the rotary support according to two or more parallel and adjacent rows of spraying nozzles. For, example, the parallel and adjacent rows of spraying nozzles can be three or more in number. The rows are parallel to the rotation axis of the rotary support and therefore parallel to a plane containing the paper web to be sprayed. Preferably, the spraying nozzles of each row are staggered with regard to the spraying nozzles of an adjacent row.
In a preferred embodiment, each of said spraying nozzles is connected to at least three conduits supported on the support on which the spraying nozzles are arranged, preferably said rotary support. A first one of said conduits is a main liquid product supply tube providing a liquid product to be sprayed. A second one of the conduits is a first pressurized gas supply tube providing a pressurized gas used to generate a spray jet in combination with the liquid product. The third one of the conduits is a second pressurized gas supply tube providing a pressurized gas used to blow surrounding the spray jet and thus adjust a cone shape of said spray jet. Preferably, the pressurized gas is pressurized air. Each spraying nozzle can be connected to auxiliary conduits providing auxiliary liquid products to be alternatively or simultaneously sprayed in addition to these three conduits.
Each of said conduits has associated thereto regulation means allowing to control a supply pressure of each of the liquids or gasses in order to project a spray jet on the inner surface of said moving paper web with a controlled speed of impact of the sprayed product and a controlled width of a cone shape of the sprayed product. In general, it is convenient to regulate the speed of spray jet so as the sprayed liquid product adhere to the paper web without rebounding therefrom.
Generally, the spray chamber is also delimited in part by portions of the tubular wall of the rotary support adjacent to its longitudinal opening. In one embodiment, at least two of the guide rollers are arranged adjacent to the tubular wall of the rotary support, such that the spray chamber is delimited by the paper web, by the portions of the tubular wall adjacent to its longitudinal opening, and by the side walls.
Preferably, the spraying nozzles are axially movable along guides associated with the rotary support in a direction parallel to the axes of the guide rollers and can be fixed in a selected position along the rotary support to centre or adjust the position of the spraying nozzles with respect to the paper web. A valve arrangement also allows individually opening and closing each of the spraying nozzles to adjust the number of active spraying nozzles to the width of the paper web being treated, in each case.
In one embodiment, one or more of the guide rollers can be moved in a direction perpendicular to its own axis to facilitate access to the spray chamber, even when the paper web is installed on the guide rollers.
In one embodiment, the spraying device further comprises a cleaning chamber located outside the spray chamber and outside the tubular wall of the rotary support. This cleaning chamber internally has a plurality of cleaning nozzles connected to a cleaning liquid supply source, said cleaning liquid being water or another solvent suitable for dissolving the liquid product used. The rotary support can be rotated to an angular cleaning position in which the longitudinal opening of the tubular wall of the rotary support is facing the cleaning chamber and the spraying nozzles are facing said cleaning nozzles.
In one embodiment, the cleaning chamber includes cleaning brushes that interfere with the spraying nozzles preferably while the cleaning liquid is sprayed by the cleaning nozzles. Preferably, the cleaning brushes are movable to sweep an outlet and/or areas adjacent to the outlet of the spraying nozzles.
Additionally, the cleaning liquid can also be circulated through the circuit supplying the liquid product to the spraying nozzles in order to clean said circuit and the inside of the spraying nozzles at the end of an operation for applying a liquid product on a paper web.

Brief Description of the Drawings

The above and other features and advantages will be better understood from the following detailed description of exemplary embodiments, which are merely illustrative and not limitative, with reference to the accompanying drawings, in which:

Figure 1 is a cross-sectional view of a spraying device for spraying a liquid product onto a paper web according to an embodiment of the present invention, in a working position;
Figure 2 is a cross-sectional view of the spraying device of Figure 1 in a cleaning position;
Figure 3 is a cross-section view of a spraying device for spraying a liquid product onto a paper web according to another embodiment of the present invention.
Figure 4 is a front perspective view of the spraying device of Figure 1;
Figure 5 is a rear perspective view of the spraying device of Figure 1;
Figure 6 is a sectioned partial view of a rotary support with a tubular wall included in the spraying device of Figure 1;
Figure 7 is a partial cross-section view of fluid connections for a spraying nozzle according to another embodiment of the invention;
Figure 8 is a front view showing a particular arrangement of the spraying nozzles according to still another embodiment of the invention; and
Figure 9 is a partial cross-section view of a cleaning device according to still another embodiment of the invention.

Detailed Description of Exemplary Embodiments

Figures 1, 2, 4 and 5 show a spraying device for spraying a liquid product onto a paper web, comprising a structure 8 on which there are supported mutually parallel guide rollers 6 guiding the path of a moving paper web 2. The axes of the guide rollers 6 are not in the same plane, such that the guide rollers 6 define between them a plurality of sections of the paper web forming different angles with one another.
There is further supported on the structure 8 of the spraying device a rotary support 7 rotatable about a rotation axis parallel to the axis of the guide rollers 6. On said rotary support 7 there are arranged a plurality of spraying nozzles 1 distributed along the length thereof and connected to a liquid product supply source. In this embodiment, the spraying nozzles 1 are arranged in a single row parallel to the rotation axis. The rotary support 7 (described in further detail below in relation to Figure 6) includes a tubular wall 7a defining an enclosure in which the spraying nozzles are installed. The tubular wall 7a has a longitudinal opening 4 facing and aligned with the spraying nozzles 1.
In an alternative embodiment shown in Figure 8, spraying nozzles 1 are arranged on the rotary support 7 according two or more parallel and adjacent rows of spraying nozzles 1, wherein the rows are parallel to the rotation axis and therefore parallel to a plane containing the paper web 2 to be sprayed. The spraying nozzles 1 of each row are staggered with regard to the spraying nozzles 1 of an adjacent row.
The spraying device further comprises a pair of side walls 5 perpendicular to the axes of the guide rollers 6 supported in the structure 8. These side walls 5 are configured according to the path of the different sections of the paper web 2 and are separated from one another by a distance according to the width of the paper web 2.
Two of the guide rollers 6 are arranged adjacent to the tubular wall 7a of the rotary support 7, such that several of the different contiguous sections of the paper web 2, portions of the tubular wall 7a of the rotary support 7 adjacent to the longitudinal opening 4, and the side walls 5 delimit an inner space forming the spray chamber 3. Two of the guide rollers 6 are located inside the spray chamber 3. The liquid product is sprayed by the spraying nozzles 1 through the longitudinal opening 4 into the spray chamber 3 and onto the paper web 2.
Two contiguous sections of the paper web 2 together forming an acute angle containing, including or encompassing the spraying nozzles 1 are defined between one of the guide rollers 6 located inside the spray chamber 3 and two other guide rollers 6.
The spraying nozzles 1 are directed towards one of the sections of the moving paper web 2 so as to apply the liquid product sprayed thereon. The rotary support 7 together with the tubular wall 7a can be rotated with respect to said rotation axis so as to regulate the spraying angle of the spraying nozzles 1 with respect to the section of the paper web 2 on which the sprayed liquid product is to be applied.
The side walls 5 are connected to guide rods 9 (Figure 4) supported on the structure 8, such that the side walls are movable in a direction parallel to the axes of the guide rollers 6 and can be fixed in desired positions to adjust the width of the spray chamber 3 to the width of the paper web 2. The spraying nozzles 1 are axially movable along the rotary support 7 in a direction parallel to the axes of the guide rollers 6.
The circuit supplying the liquid product to the spraying nozzles 1 includes a valve arrangement which allows individually opening and closing each of the spraying nozzles 1. So when a paper web 2 is used that is narrower than the maximum allowable width of the device, only those spraying nozzles 1 which are inside the spray chamber 3 will be left active, while the rest will be closed.
Additionally, at least one of the guide rollers 6 adjacent to the tubular wall 7a of the rotary support 7 can be moved in a direction perpendicular to its own axis to facilitate access to the spray chamber 3 even when the paper web 2 is installed on the guide rollers 6.
The spraying device of the present invention further comprises a cleaning chamber 12 provided with a plurality of cleaning nozzles 10 connected to a cleaning liquid supply source. This cleaning chamber 12 is located outside the spray chamber 3 and outside the tubular wall 7a of the rotary support 7. The rotary support 7 can be rotated to an angular cleaning position (Figure 2) in which the longitudinal opening 4 of the tubular wall 7a is facing the cleaning chamber 12 and the spraying nozzles 1 are facing the cleaning nozzles 10. The cleaning liquid can therefore be sprayed by the cleaning nozzles 10 onto the spraying nozzles 1 and other elements housed inside the tubular wall 7a. In Figure 2, the paper web is not installed on the guide rollers 6. In an alternative embodiment shown in Figure 9, the cleaning chamber 12 includes cleaning brushes 30 arranged adjacent the cleaning nozzles 10 that interfere with the spraying nozzles preferably while the cleaning liquid is sprayed by the cleaning nozzles 10. In the example shown, the cleaning brushes 30 are mounted on a support 11 which is rotated about an axis parallel to a central axis of the cleaning nozzle 10 by actuating means (not shown), to sweep an outlet 1 a of the spraying nozzles 1 and/or areas adjacent thereto.
During a cleaning operation, the cleaning liquid can also be circulated through the circuit supplying the liquid product to the spraying nozzles 1 in order to clean said circuit and the inside of the spraying nozzles 1, and through a fixed conduit 28 provided with nozzles 29 located inside the tubular wall 7a (described in further detail below in relation to Figure6) in order to clean the inner surfaces of the tubular wall 7a and other elements housed therein at the end of an operation for applying a liquid product on a paper web 2.
Figure 3 shows another embodiment of the spraying device which only differs from the one described above with reference to Figures 1, 2, 4 and 5 in the arrangement of the guide rollers 6 and therefore in the path followed by the moving paper web 2. In the embodiment of Figure 3, there are two guide rollers 6 adjacent to the tubular wall 7a of the rotary support 7 and a third guide roller 6 located therebetween and away from the tubular wall 7a of the rotary support 7, so that the spray chamber 3 is delimited by the two contiguous sections of the paper web 2 defined by these three guide rollers 6, portions of the tubular wall 7a of the rotary support 7 adjacent to the longitudinal opening 4, and the side walls 5. The mentioned two contiguous sections of the paper web 2 together form an angle containing, including or encompassing the spraying nozzles 1.
Figure 6 shows in detail one end of the tubular wall 7a of the rotary support 7 of either the embodiment of Figures 1, 2, 4 and 5 or the embodiment of Figure 3. Each end of the tubular wall is supported and guided in a rotational manner with respect to the structure 8 by a plurality of wheels 13 (only one of which can be seen in Figure 6) rolling on a cylindrical outer surface of the tubular wall 7a. Optionally, a motor (not shown) is operatively connected to rotate the tubular wall 7a about its longitudinal axis.
The inner enclosure of the tubular wall 7a is closed at its ends by end walls 14. A main liquid product supply tube 15 and a pressurized gas supply tube 16 securely connected to one another by connection members 21 are installed inside the tubular wall 7a. Each end of the main liquid product supply tube 15 is surrounded by a jacket 27 going through the corresponding end wall 14 of the tubular wall 7a through a sliding friction bearing 19. Each end of the pressurized gas supply tube 16 goes through the end wall 14 of the tubular wall 7a through a corresponding sliding friction bearing 20. The main liquid product supply tube 15 and the pressurized gas supply tube 16 can therefore slide axially with respect to the tubular wall 7a and rotate together with the tubular wall 7a with respect to the axis thereof.
The outer ends of the main liquid product supply tube 15 and of the pressurized gas supply tube 16 are connected to a main liquid product supply source and to a pressurized gas supply source (not shown), respectively. Advantageously, the pressurized gas can be pressurized air. Inside the tubular wall 7a, the main liquid product supply tube 15 has a plurality of connectors 17 distributed along same and the pressurized gas supply tube 16 has a plurality of connectors 18 also distributed along same.
The connection members 21 support auxiliary liquid product supply tubes 23, 24, each of which also has a plurality of connectors 25, 26 distributed along same. These auxiliary liquid product supply tubes 23, 24 can be connected to respective auxiliary liquid product supply sources (not shown) through respective conduits (not shown) going through the jacket 27 into an annular space between the main liquid product supply tube 15 and the jacket 27.
The connection members 21 have a longitudinal support (not shown) fixed thereto where there are installed a series of sprayer groups (not shown) distributed along the length of the tubular wall 7a. Each sprayer group includes one of the spraying nozzles 1 associated with one or more valves, and connecting sleeves connect the mentioned connectors 17, 18, 25, 26 to inlet ports of said one or more valves. The liquid product sprayed by the spraying nozzles 1 is therefore a mixture of main liquid product and pressurized gas, and optionally other auxiliary liquid products.
One or more fluid dynamic cylinders 22 are all operatively connected to jointly move the main liquid product supply tube 15, the pressurized gas supply tube 16, the auxiliary liquid product supply tubes 23, 24 and the connection members 21 in an axial direction with respect to the tubular wall 7a.
A fixed conduit 28 provided with a plurality of nozzles 29 distributed along same is further installed inside the tubular wall 7a. At least one end of the fixed conduit 28 goes through the end wall 14 through a corresponding hole and is connected to a cleaning liquid supply source. The nozzles 29 of the fixed conduit 28 are therefore used to spray cleaning liquid on inner surfaces of the tubular wall 7a and other members housed therein at the end of an operation for applying a liquid product on paper web.
Figure 7 shows an alternative embodiment where each of said spraying nozzles 1 is connected to three conduits supported on the rotary support 7. A first one of said conduits is a main liquid product supply tube 15 providing the liquid product to be sprayed. A second one of the conduits is a first pressurized gas supply tube 16a providing a pressurized gas used to generate a spray jet in combination with the liquid product, and the third one of the conduits is a second pressurized gas supply tube 16b providing a pressurized gas to adjust a cone shape of said spray jet. The liquid product supply tube 15 and the first and second pressurized gas supply tube 16a, 16b are securely connected to one another and to the rotary support 7 by connection members 21 installed inside the tubular wall 7a.
The liquid product supply tube 15 and the first and second pressurized gas supply tube 16a, 16b are connected to the spraying nozzle 1 by respective connecting sleeves 31, 32, 33. Although not shown in Figure 7, the connection members 21 can further support auxiliary liquid product supply tubes, analogous to the auxiliary liquid product supply tubes 23, 24 shown in Figure 6, connected to the spraying nozzles 1 to provide auxiliary liquid products to be alternatively or simultaneously sprayed.
Each of the liquid product supply tube 15, first and second pressurized gas supply tube 16a, 16b and auxiliary liquid product supply tubes has associated thereto regulation means (not shown) allowing to control a supply pressure of each of the liquids or gasses in order to project a spray jet on the inner surface of the moving paper web 2 with a controlled speed of impact of the sprayed product and a controlled width of a cone shape of the sprayed product.
The scope of the present invention is defined in the attached claims.

Claims

A spraying device for spraying a liquid product onto a paper web, comprising a spray chamber (3) delimited at least in part by a moving paper web (2) guided by guide rollers (6), and a plurality of spraying nozzles (1) connected to a liquid product supply source and arranged inside said spray chamber (3) to spray said liquid product onto said moving paper web (2), characterized in that:
- said plurality of spraying nozzles (1) are arranged on a rotary support (7) rotatable about a rotation axis parallel to the axes of the guide rollers (6);

- the spray chamber (3) is delimited by at least part of said rotary support (7), by at least two contiguous sections of the paper web (2), each of said sections of the paper web being defined between two of said guide rollers (6), and by side walls (5) perpendicular to the axes of the guide rollers (6); and

- one of said contiguous sections of the paper web (2) faces directly the spraying nozzles.
The spraying device according to claim 1, wherein said spraying nozzles (1) are arranged according to at least two parallel and adjacent rows of spraying nozzles (1), the rows being parallel to a plane containing said paper web (2) to be sprayed.
The spraying device of claims 2, wherein it comprises at least three rows of spraying nozzles (1).
The spraying device according to claim 2 or 3, wherein the spraying nozzles (1) of each row are staggered with regard to the spraying nozzles (1) of an adjacent row.
The spraying device according to any one of the previous claims, wherein said two contiguous sections of the paper web (2) together form an angle containing, including or encompassing the spraying nozzles (1).
The spraying device according to any of the previous claims, wherein said side walls (5) are movable in a direction parallel to the axes of the guide rollers (6) to adjust the width of the spray chamber (3) to the width of the paper web (2).
The spraying device of claims 1, wherein the spraying nozzles (1) are arranged in a row parallel to said rotation axis of the rotary support (7), and the rotary support (7) can be rotated with respect to the rotation axis to regulate an spraying angle of the spraying nozzles (1).
The spraying device according to any one of claims 2 to 6, wherein said parallel and adjacent rows of spraying nozzles (1) are parallel to said rotation axis of the rotary support (7), and the rotary support (7) can be rotated with respect to an the rotation axis to regulate an spraying angle of the spraying nozzles (1).
The spraying device according to claim 7 or 8, wherein said rotary support (7) includes a tubular wall (7a) defining an enclosure in which the spraying nozzles are installed, and said tubular wall (7a) has at least one longitudinal opening (4) through which the liquid product is sprayed into the spray chamber (3) by the spraying nozzles (1), at least part of said tubular wall (7a) contributing to delimit the spray chamber (3).
The spraying device according to any one of the previous claims, wherein each of said spraying nozzles (1) is connected to at least three conduits supported on said support on which the spraying nozzles (1) are arranged: a first one of said conduits being a main liquid product supply tube (15) providing a liquid product to be sprayed; a second one of the conduits being a first pressurized gas supply tube (16a) providing a pressurized gas to generate a spray jet; and a third one of the conduits being a second pressurized gas supply tube (16b) providing a pressurized gas to adjust a cone shape of said spray jet.
The spraying device according to claim 10, wherein each of said conduits has associated regulation means allowing to control a supply pressure of each of the liquids or gasses in order to project a spray jet on the inner surface of said moving paper web with a controlled speed of impact of the sprayed product and a controlled width of a cone shape of the sprayed product.
The spraying device according to any of the previous claims, wherein said spraying nozzles (1) are axially movable along the rotary support (7) in a direction parallel to the axes of the guide rollers (6).
The spraying device according to claim 9, further comprising a cleaning chamber (12) provided with a plurality of cleaning nozzles (10) connected to a cleaning liquid supply source, where said cleaning chamber (12) is located outside the spray chamber (3) and outside the tubular wall (7a) of the rotary support (7), and where said rotary support (7) can be rotated to an angular cleaning position in which the longitudinal opening (4) of the tubular wall (7a) is facing the cleaning chamber (12) and the spraying nozzles (1) are facing said cleaning nozzles (10).
The spraying device according to claim 13, wherein said cleaning chamber (12) includes cleaning brushes (30) that interfere with the spraying nozzles (1).
The spraying device according to claim 1, wherein at least two of the guide rollers (6) are arranged adjacent to the tubular wall (7a) of the rotary support (7), and at least one of the guide rollers (6) adjacent to the tubular wall (7a) of the rotary support (7) can be moved in a direction perpendicular to its own axis to facilitate access to the spray chamber (3).