Abstract
A cleaning device, in particular for a suction roller, for a machine for producing or processing a fibrous web, includes a distribution line and a number of cleaning nozzles which can be supplied with a cleaning fluid via the distribution line. At least one cleaning nozzle, in particular all of the cleaning nozzles, are in the form of oscillating nozzles. A suction roller and a method for cleaning a suction roller are also provided.
Claims
1-14. (canceled)
15. A cleaning device or a cleaning device for a suction roller for a machine for producing or processing a fibrous web, the cleaning device comprising: a distribution line; and a plurality of cleaning nozzles to be supplied with a cleaning fluid by said distribution line; at least one or all of said cleaning nozzles being oscillating nozzles configured as fluid oscillators generating a fluid jet oscillating in a jet plane.
16. The cleaning device according to claim 15, wherein said oscillating nozzles include a first quantity and a second quantity of oscillating nozzles, said jet planes of said fluid jets of said first and second quantities of oscillating nozzles define exit angles differing from each other, and said exit angles are angles which said jet planes enclose with the vertical.
17. The cleaning device according to claim 16, wherein said oscillating nozzles of said first and second quantities are disposed alternatingly.
18. The cleaning device according to claim 15, wherein at least some or all of said oscillating nozzles have an angled shape deflecting said jet plane inside said oscillating nozzles.
19. The cleaning device according to claim 18, wherein said jet plane is deflected by an angle of between 1° and 90°.
20. The cleaning device according to claim 18, wherein said jet plane is deflected by an angle of between 5° and 45°.
21. The cleaning device according to claim 16, wherein said exit angles of said jet planes of said first quantity and said second quantity differ by more than 2°.
22. The cleaning device according to claim 16, wherein said exit angles of said jet planes of said first quantity and said second quantity differ by between 5° and 25°.
23. The cleaning device according to claim 15, which further comprises a detachable connection, a screw connection or a plug connection connecting said cleaning nozzles to said distribution line.
24. The cleaning device according to claim 15, wherein said cleaning nozzles are mutually spaced apart by a respective gap of less than 500 mm.
25. The cleaning device according to claim 15, wherein said cleaning nozzles are mutually spaced apart by a respective gap of between 150 mm and 350 mm.
26. The cleaning device according to claim 15, wherein said oscillating fluid jet covers an oscillation angle within a range of between 90° and 170°.
27. The cleaning device according to claim 15, wherein said oscillating fluid jet covers an oscillation angle of 120°.
28. The cleaning device according to claim 15, wherein at least one or all of said oscillating nozzles are completely or partially made of a metal or a plastic.
29. A suction roller for a machine for producing or processing a fibrous web, the suction roller comprising at least one cleaning device according to claim 15.
30. The suction roller according to claim 29, wherein the at least one cleaning device is disposed inside the suction roller.
31. A method for cleaning a suction roller, the method comprising: providing a suction roller according to claim 29; applying a fluid or spraying water to the at least one cleaning device; and delivering the fluid or spraying water at a pressure of less than 40 bar.
32. The method according to claim 31, which further comprises delivering the fluid or spraying water at a pressure of less than 10 bar.
33. The method according to claim 32, which further comprises delivering the fluid or spraying water at a pressure of between 1 and 5 bar.
34. The method according to claim 31, which further comprises delivering the fluid or spraying water at less than 20 l/min/m for cleaning.
35. The method according to claim 31, which further comprises delivering the fluid or spraying water at between 9 l/min/m and 11 l/min/m for cleaning.
Description
[0047] Further advantageous embodiments of the invention are explained with the aid of exemplary embodiments and with reference to the drawings. The features mentioned can advantageously be implemented not only in the combination illustrated but can also individually be combined with one another. In detail, in the drawings:
[0048] FIGS. 1a, 1b, and 1c show examples of fluid oscillators from the prior art.
[0049] FIG. 2 shows schematically a section through the structure of an angled oscillating nozzle according to an aspect of the invention.
[0050] FIG. 3 shows schematic views of an angled oscillating nozzle according to an aspect of the invention.
[0051] FIG. 4 shows schematically a portion of a cleaning device according to another aspect of the invention.
[0052] FIGS. 5a, 5b, and 5c show details of a cleaning device according to an aspect of the invention.
[0053] The drawings are described in more detail below.
[0054] FIGS. 1a, 1b, and 1c show schematically different embodiments of fluid oscillators known from the prior art which are suited for use in oscillating nozzles 20 according to different aspects of the present invention. However, the present inventions are not limited to these designs of the fluid oscillators. In general, all types of fluid oscillators are suited. The fluid can enter the flow space through an inlet 1. As shown in FIG. 1c, an accelerating nozzle, for example with a tapered shape, may be provided. The fluid then enters the oscillation chamber 3. Flow obstacles 6 in the form of islands 6 can be provided in the oscillation chamber 3, depending on the type of oscillator. Alternatively or additionally, return ducts 4 can also be provided which return parts of the fluid flow back toward the inlet 1. The fluid then leaves at the outlet 7 as an oscillating jet 10.
[0055] In the embodiment in FIG. 1a, the flow passes straight through the oscillator, i.e. the direction of the flow into the inlet 1 lies within the plane of the oscillating jet 10. In the embodiments in FIGS. 1b and 1c, the flow inlet 1 is from below. The flow is deflected upstream from the actual oscillator.
[0056] FIG. 2 shows an angled oscillating nozzle 20 according to an aspect of the invention. In this embodiment, the fluid is conducted into the nozzle 20 via an inlet 1. Although not absolutely necessary, the fluid is then advantageously conducted through an accelerating nozzle 2, into the oscillation chamber 3 via the oscillator inlet 3a. An oscillator which comprises two return ducts 4 is illustrated in FIG. 2. The nozzle in FIG. 2 has a constriction 5 at the point at which the outlet 7 is arranged in the known oscillators. The fluid is then conducted through two ducts 12 which are separated by an island 6. It is very advantageous if the ducts and the island 6 have a high degree of symmetry. The island 6 can in particular have a circular, elliptical, drop-shaped, or similar design. The ducts 12 are rejoined downstream from the island 6 and the fluid subsequently leaves the nozzle 20 via an outlet 7 as an oscillating jet. The region between the constriction 5 and the outlet 7 is referred to as a wake region 11. Together with the oscillator, the wake region 11 here forms the inside of the nozzle 20. In order to ensure that the oscillating jet 10 and the inflow direction do not lie within the same plane, the oscillating nozzle 20 has an angled design. In order not to disrupt the effect of the oscillator, the nozzle 20 is angled by an exit angle inside the wake region. This exit angle can advantageously be between 1° and 90°, in particular between 5° and 45°. An angle of 30° is illustrated by way of example in FIG. 2. In order to prevent the oscillating jet 10 from widening out downstream from the outlet 7, a lip 8 is provided in the nozzle 20 in FIG. 2. It prevents the jet 20 from swerving downward. It can alternatively or additionally be provided that a lip 8 is provided which prevents the jet from swerving upward. The lip 8 or lips 8 is or are not angled or curved in FIG. 2 and instead has or have a straight design. Angling or curving the lips 8 is not necessary in order to deflect the jet because the angling happens earlier inside the nozzle 20. In some cases, it can nevertheless be expedient to provide additional curving or additional angling in the region of the lips 8.
[0057] Such an angled oscillating nozzle 20 can be used for a wide range of applications. It is in particular exceptionally well suited for use as an oscillating nozzle 20 in a cleaning device 100 according to an aspect of the invention.
[0058] An angled oscillating nozzle 20 according to an aspect of the invention is again shown in FIG. 3 in different views from outside. The course of the internally situated flow spaces is drawn in dashed lines. B1 here designates the inlet width downstream from the accelerating nozzle 2, B2 designates the width of the constriction 5, B3 designates the width of the ducts 12, and B4 the width of the outlet 7. These four widths B1-B4, along with the length of the lip 8, influence the characteristics of the oscillating jet 10. Widening of the jet by 120° within the plane of the jet, which has proved to be very advantageous, can for example be obtained if the widths B1 and B2, i.e. the inlet width and the width of the constriction, are identical. The width of the ducts and the outlet opening can be somewhat wider than the inlet width B1. Particularly advantageous here is the combination:
B2=B1
B3=1.25*B1
B4=1.5*B1
[0059] The absolute values of these widths are of course highly dependent on the application and the desired flow rates. For application as an oscillating nozzle 20 in a cleaning device 100 according to an aspect of the invention, the width B1 can be chosen, for example, to be between 1 mm and 5 mm, in particular 2 mm. The geometry of the flow spaces advantageously remains the same over their entire height. In the embodiment in FIG. 2, the height H is chosen to be identical to the inlet width B1. This results in a square cross-section of the inlet 1. The length of the lip 8 can advantageously be at least three times as long as the inlet width B1. This is advantageous for obtaining a jet 20 which is focused in the normal direction. A very advantageous embodiment of the oscillating nozzle thus has the following dimensions:
TABLE-US-00001 B1 B2 B3 B4 H Lip 2 mm 2 mm 2.5 mm 3 mm 2 mm ≥6 mm
[0060] The nozzles 20 shown in FIGS. 2 and 3 each have a thread at their base. This is advantageous for connection to a fluid feed line. Alternatively, this connection can, however, for example, also be effected via a plug connection. In both cases, the nozzles 20 can be replaced easily. Depending on applications, however, other types of connection can also be provided, in particular also non-detachable connections to the fluid feed line.
[0061] FIG. 4 shows a portion of a cleaning device 100 according to an aspect of the invention. Such a cleaning device 100 can be used in particular as a cleaning device 100 for a suction roller 130 for a machine for producing or processing a fibrous web. A plurality of cleaning nozzles 120a, 120b are attached to a distribution line 110 which can be designed as a distribution tube 110. They can be supplied with a cleaning fluid such as, for example, spraying water by the distribution line 110. The cleaning fluid can be fed to the distribution line 110 via an individual fluid port 111 or via a plurality of fluid ports 111. The cleaning nozzles are all designed as oscillating nozzles 20 in FIG. 4. It is particularly advantageous if the cleaning nozzles are configured as angled oscillating nozzles 20, for example those described in FIGS. 2 and 3. The embodiment in FIG. 4 has a first quantity 120a and a second quantity 120b of angled cleaning nozzles, wherein the exit angles of the plane of the jet of the first quantity 120a and the second quantity 120b differ from each other. A difference of 5°-10° for the angle is often advantageous. It can thus, for example, be provided that the exit angle of the first quantity 120a is 30° and the exit angle of the second quantity 120b is 35°. It is advantageous if the gap between two neighboring cleaning nozzles is between 150 mm and 350 mm. A cleaning device 100 is illustrated in FIG. 4 in which the gap between the cleaning nozzles varies. The cleaning nozzles are here positioned, for example, in pairs consisting of a nozzle of the first and the second quantity. This can be advantageous, as explained below with the aid of FIG. 5c. Alternatively, the gap between neighboring cleaning nozzles can, however, also be identical, for example 250 mm. However, it can, for example, also be provided that larger gaps between the cleaning nozzles are provided in regions where less contamination is expected, for example at the edge of a suction roller 130, than in the other regions.
[0062] A possible method for positioning the cleaning nozzles in a cleaning device according to an aspect of the invention will be described with the aid of FIGS. 5a, 5b, and 5c. The installed situation of a cleaning device 100 in a suction roller 130 is illustrated in FIG. 5. The distribution line 110 here runs parallel to the axis of the suction roller 130, or at least largely parallel to it. The cleaning device 100 comprises, for example, a first quantity 120a and a second quantity 120b of angled oscillating nozzles 20 which are arranged alternately. The respective exit angles are designated θ1 and θ2. The gap between the cleaning device 100 and the shell of the suction roller 130 (measured from the exit point of the jet from the nozzle) is 1.sub.d. FIG. 5b shows a plan view of a device as in FIG. 5a. The oscillation angle θW, i.e. the angle covered by the oscillating jet 10 when it oscillates, can be seen here. This oscillation angle can lie, for example, between 90° and 170°. As can be seen in FIG. 5b, the nozzles 20 can be arranged such that, in the case of neighboring nozzles, the regions in which the jets 10 oscillate overlap. It is then advantageous here if respective neighboring nozzles 20, 120a, 120b have different exit angles θ1, θ2. The planes of the jets of neighboring nozzles are consequently situated in space such that the jets cannot touch and consequently disrupt each other. As can be seen in FIG. 5a, the jet of the first quantity 120a strikes the shell of the suction roller 130 above the jet of the second quantity 120b. FIG. 5c illustrates why the overlapping of neighboring jet ranges according to an aspect of the invention is not only readily possible but also advantageous. The graph shows the volume flow of fluid of four neighboring oscillating nozzles 20. Visible here is a typical “M profile”, i.e. less fluid per unit time strikes the suction roller 130 at the center of the range covered than toward the edges. This is generally typical for oscillators. As described, the distribution of the fluid using a wake region 11 can be homogenized, as a result of which wider oscillation angles θW and larger ranges b.sub.S covered become possible. As a result, the cleaning device 100 can be formed with fewer nozzles 20. It can be seen that the nozzles of the first quantity 120a are positioned such that their jets do not touch each other. The nozzles of the second quantity 120b can then be positioned such that the regions with a high volume flow of the fluid are where there is a lower volume flow for the nozzles of the first quantity 120a, and vice versa. It can thus be achieved that fluid is applied evenly widthwise at the center of the shell of the suction roller 130, and also other moving surfaces which need to be cleaned or moistened. The value b.sub.S in FIG. 5c moreover describes the width of the region covered by the oscillating jet 10. With the aid of the oscillation angle θW and the gap between the oscillating nozzle 20 and the shell of the suction roller 130, this width is determined by
[00002]
[0063] It has been shown to be advantageous to position the cleaning nozzles, as illustrated in FIG. 4, in pairs consisting of a nozzle of the first and the second quantity. These two nozzles of a pair have the gap 1.sub.A, whilst the gap to the first nozzle of the next pair is l.sub.B. Preferably, l.sub.A=0.25 b.sub.S and l.sub.B=0.75 b.sub.S. Particularly homogeneous cleaning of the suction roller 130 results. More generally, the gaps should be chosen to be:
l.sub.A∈[0.2.0.3]b.sub.S; l.sub.B∈[0.7.0.8]b.sub.S
LIST OF REFERENCE SYMBOLS
[0064] 1 inlet
[0065] 2 accelerating nozzle
[0066] 3 oscillation chamber
[0067] 3a oscillator inlet
[0068] 4 return ducts
[0069] 5 constriction
[0070] 6 island
[0071] 7 outlet opening
[0072] 8 lip
[0073] 9 exit angle
[0074] 10 oscillating jet
[0075] 11 wake region
[0076] 12 duct
[0077] 15 flow chamber
[0078] 20 oscillating nozzle
[0079] 100 cleaning device
[0080] 110 distribution line
[0081] 111 fluid port
[0082] 120a first quantity
[0083] 120b second quantity
[0084] 130 suction roller
[0085] B1 inlet width
[0086] B2 width of the constriction
[0087] B3 width of the ducts
[0088] B4 width of the outlet opening
[0089] H height of the flow chamber
[0090] θ1, θ2 exit angle
[0091] θW oscillation angle
