US20180119349A1

US20180119349A1 - Cleaning Device

Info

Publication number: US20180119349A1
Application number: US15/566,777
Authority: US
Inventors: Mark Hodson; Karlheinz Straub
Original assignee: Voith Patent GmbH
Current assignee: Voith Patent GmbH
Priority date: 2015-04-15
Filing date: 2016-04-14
Publication date: 2018-05-03
Also published as: EP3283685A1; EP3283685B1; WO2016166192A1; DE102015206747A1; CN107454918A

Abstract

A device for cleaning a continuously revolving clothing in a machine producing and/or processing a paper, cardboard, tissue or other fiber web, includes at least one cleaning nozzle generating at least one fluid cleaning jet directed towards the clothing and a channel discharging fluid and dirt from the clothing in a discharge direction. The discharge channel has a first portion with a receptacle opening at the beginning of the discharge channel and a cleaning opening facing the clothing forming a cleaning zone. The nozzle causes the jet to impact the clothing in the cleaning zone. The receptacle opening is oriented opposite a clothing running direction and the nozzle provides the jet with a velocity component transverse to the running direction striking the clothing in an angular range 20°<B<80°, particularly 30°<B<70° relative to a clothing plane seen in the clothing running direction.

Description

The invention relates to a device for cleaning a continuously revolving clothing in a paper machine for producing and/or processing a paper, cardboard, or tissue web or another fibrous web, said device comprising at least one cleaning nozzle which from a fluid generates at least one cleaning jet that is directed onto the clothing, and a discharge duct for discharging the fluid and the dirt that is released from the clothing by the cleaning jet in a discharging direction, wherein the discharge duct has a first portion having a receptacle opening at the beginning of the discharge duct, wherein the first portion of the discharge duct has a cleaning opening that points toward the revolving clothing and forms a cleaning zone, and the at least one cleaning nozzle is disposed in such a manner that the at least one cleaning jet impacts the clothing in the region of the cleaning zone.
The invention also relates to a method for cleaning a continuously revolving clothing in a paper machine for producing and/or processing a paper, cardboard, or tissue web or another fibrous web.
Different clothings are used in the various sections of a paper machine. Said clothings serve for transporting the fibrous web from one section to another, on the one hand, and said clothings are tuned to the technological procedures in the respective sections, on the other hand. The forming screens in the forming section facilitate the uniform de-watering of the fibrous suspension; the press felts in the press section absorb the water that has been squeezed out; and said clothings in the drying section support the fibrous web and transport the water vapor away from the fibrous web.
In all cases, the clothings are contaminated with fines, fillers, and impurities from the fibrous web. In order for the properties of the clothings to remain consistent for as long as possible and to be compromised to the least possible extent, said clothings need to be cleaned. This applies not only to the air-permeable and water-permeable clothings mentioned, but also to water-impermeable belts which are used in the press section, for example.
A known cleaning device is known from publication WO 2005/113890 A1. It is proposed therein for a cleaning nozzle for cleaning a transportation belt to be used such that the cleaning jet always impacts the transportation belt counter to the running direction of the transportation belt. The cleaning nozzle herein in the running direction of the transportation belt is disposed behind or at the end of the cleaning device. This arrangement has the disadvantage that the mixture of cleaning medium and dirt always has to be suctioned counter to the running direction of the transportation belt. This requires a correspondingly high input of energy. Also, there is a noticeable tendency towards contamination of the surroundings by the formation of fog which can also be charged with dirt particles, in particular when the suction output in the suction duct is held at too low a level, or when the velocity of the cleaning jet is increased.
The invention is therefore based on the object of avoiding the disadvantages of the known cleaning devices, of improving the cleaning effect, and of proposing a simple and cost-effective device.
The object is achieved by the features of claim 1.
A device for cleaning a continuously revolving clothing in a paper machine for producing and/or processing a paper, cardboard, or tissue web or another fibrous web is proposed said device comprising at least one cleaning nozzle which from a fluid generates at least one cleaning jet that is directed onto the clothing, and a discharge duct for discharging the fluid and the dirt that is released from the clothing by the cleaning jet in a discharging direction. The discharge duct has a first portion having a receptacle opening at the beginning of the discharge duct, wherein the first portion of the discharge duct has a cleaning opening that points toward the revolving clothing and forms a cleaning zone, and that the at least one cleaning nozzle is disposed in such a manner that the at least one cleaning jet impacts the clothing in the region of the cleaning zone. It is provided according to the invention that the receptacle opening points counter to the running direction of the revolving clothing, and in that the at least one cleaning nozzle is disposed such that the at least one cleaning jet has a velocity component in the transverse direction, that is to say transversely to the running direction of the clothing, and, when viewed in the running direction of the clothing, the cleaning jet (4) in relation to the clothing plane impacts the clothing at an angular range of 20°<B<80°, in particular at an angular range of 30°<B<70°.
The clothing plane is meant to be that plane which is defined by the continuously revolving clothing, preferably in the region of the device and preferably in the region of the cleaning zone. The cleaning zone is to be understood to be that space which is delimited by the discharge duct, preferably by the first portion of the latter, and the clothing that revolves directly opposite said discharge duct, thus the clothing plane.
When mention is made of the receptacle opening pointing counter to the running direction of the revolving clothing, this is to be understood as follows: the extension of the longitudinal central axis of the first portion of the discharge duct together with the running direction of the clothing, preferably when viewed in the region of the cleaning zone, forms the smallest angle seen, which is less than 90° and preferably is smaller than or equal to 45°. The feature according to the invention of the receptacle opening pointing counter to the running direction of the revolving clothing refers to the operation of the device according to the intended use. The latter is present when the device is disposed in on the on paper machine in relation to the clothing, and when the at least one cleaning jet impacts the clothing.
The angle B lies in the plane that is defined by the transverse direction and a perpendicular to the clothing plane.
The cleaning jet thus impacts the region of the cleaning zone. The term region preferably also includes that region that is close to the periphery and adjacent to the cleaning opening, as long as the fluid and the released dirt can be reliably discharged in the discharge duct. In this case, the cleaning zone is larger than the cleaning opening.
The at least one cleaning nozzle is preferably disposed so as to be stationary in relation to the device.
According to the invention, the receptacle opening is disposed counter to the running direction of the clothing to be cleaned. On account thereof, a driving effect is created by the entrained air barrier layer. The kinetic energy of the air barrier layer entrained by the clothing herein is utilized for facilitating the discharge of the fluid and the dirt that is released from the clothing by the cleaning jet into the discharge duct. The discharging direction and the running direction of the clothing thus point in substantially the same direction. Both directions can also diverge by up to 30° from one another without the action of the driving effect being substantially compromised. The contamination of the surroundings is likewise reduced by this arrangement, since the impact point of the cleaning jet on the clothing lies entirely within the first portion of the discharge duct. Additionally, the cleaning effect is improved by the orientation of the cleaning jet according to the invention. In the case of clothings, in particular in the case of drying screens, the cleaning jet by virtue of the weaving structures can penetrate further into the woven drying screen fabric and clean a larger portion of the open volume.
The device can be embodied so as to be separate from the paper machine. This means that said device is capable of being (can be) disposed in the region of the continuously revolving clothing of the paper machine, and the at least one cleaning jet is directable onto the clothing.
The device for cleaning is preferably disposed on the external side of the revolving clothing, that is to say on that side of the clothing that faces the fibrous web, and can be coupled to a traversing installation that extends in the transverse direction, that is to say in the direction that is transverse to the running direction of the clothing.
In one practical embodiment, the at least one cleaning nozzle is disposed such that the at least one cleaning jet, when viewed in a plane that is parallel with the clothing plane, in relation to the transverse direction impacts the clothing at an angular range of −45°<A<45°. When viewed in the running direction 9, the cleaning jet impacts the clothing plane at an angle B, on the one hand, and said cleaning jet is preferably oriented so as to be transverse to the running direction of the clothing, on the other hand. In one practical case, good results were able to be achieved at an angular range of −20°<A<20°. Very good results for many clothings could be achieved a complete orientation in the transverse direction, that is to say at A=0°. The angle A thus lies in the plane that is defined by the transverse direction and the running direction of the clothing.
In one further practical design embodiment, the first portion of the discharge duct in the region of the cleaning opening is assigned a sliding shoe, wherein the sliding shoe surrounds the cleaning opening, that is to say that the sliding shoe does not obscure the cleaning opening. The first portion of the discharge duct herein is connected to the sliding shoe, for example by screw-fitting or welding. The sliding shoe during the cleaning operation of the device slides on the clothing, or has a minor spacing of less than 3 mm, preferably less than 2 mm therefrom. On account of the direct contact with the clothing, or on account of the minor spacing from the clothing, the suction space of the first portion of the discharge duct is sealed in relation to the surroundings such that flows of air or fog that arise from the first portion of the discharge duct are prevented or at least minimized. Contamination of the device and of the surroundings is reduced on account thereof. The fluid that is reflected by the clothing and the dirt that is released therefrom are completely discharged.
According to one refinement it is possible for the sliding face of the side of the sliding shoe that faces the clothing to be provided with grooves wherein the grooves in the running direction of the clothing can extend from the beginning of the sliding shoe up to the cleaning opening.
It is furthermore also conceivable for the first portion of the discharge duct in the region of the cleaning opening to be embodied such that said first portion, without the use of a sliding shoe, bears directly on the clothing. To this end, a sliding face is configured on the first portion of the discharge duct.
In one further potential embodiment, the periphery that surrounds the cleaning opening of the first portion of the discharge duct, or of the sliding shoe, that forms the cleaning zone is provided with a slant. The slant herein is embodied such that the face of the cleaning opening increases in size toward the interior space of the discharge duct. This shape has proven advantageous in terms of discharging coarse contaminants that adhere to the clothing. On account of this geometry, the dirt is scraped from the clothing and discharged.
In one advantageous variant of embodiment, the flow cross section of the first portion of the discharge duct increases in the discharging direction. The receptacle opening thus has the smallest cross section of the first portion of the discharge duct. On account thereof, the risk of leakage of fluid and contaminants as a result of air turbulence is counteracted. However, it is also conceivable for the flow cross section to decrease or remain consistent.
In order for the adherence of dirt to the internal wall of the first portion of the discharge duct, in particular of the entire discharge duct, to be avoided, the flow cross section at least of the first portion of the discharge duct possesses exclusively rounded corners. This is of significance in particular when the discharge duct, in particular the first portion of the discharge duct, possesses a non-circular flow cross section, for example a rectangular flow cross section. In one particularly advantageous embodiment, the flow cross section at least of the first portion of the discharge duct is embodied so as to be tubular, and is preferably made from a tube.
In order for the contamination of the first portion of the discharge duct, in particular of the entire discharge duct, to be avoided or reduced, the internal wall and/or the external wall can have non-stick properties and to this end be coated with non-stick materials or be composed of such materials. Such non-stick materials can comprise Teflon, for example.
In one practical embodiment, the face of the cleaning opening in the discharging direction is inclined in relation to the centerline of the in particular tubular discharge duct; the face of the cleaning opening in the discharging direction preferably runs so as to diverge from the centerline of the discharge duct. A particularly advantageous shape of the cleaning opening which can also be produced in a simple manner is created on account of this embodiment. If the first portion of the discharge duct is made from a tube, the cleaning opening is thus imparted a parabolic shape when the tube is not cut parallel with the centerline. If a rectangular tube is used and the cleaning opening is likewise generated by a cut that is not parallel with the centerline, a rectangular shape is thus created.
The cleaning opening advantageously begins at the receptacle opening at the beginning of the discharge duct. The air barrier layer that is entrained by the clothing can thus make its way unimpeded into the first portion of the discharge duct and into the open cleaning zone.
In one practical embodiment, the cleaning opening has a shape which in particular steadily tapers in the discharging direction. Said cleaning opening has a parabolic shape, for example. Since the cleaning opening runs parallel with the clothing plane and is preferably in contact with the latter or is positioned at a minor spacing therefrom, contaminants that adhere to the clothing can thus be gently scraped off by the periphery of the cleaning opening. Vibrations are thus also not created such as can be the case with a rectangular shape of the cleaning opening, since the air barrier layer and the contaminants herein abruptly meet at the end edge of the opening that extends across the width of the cleaning opening.
The at least one cleaning nozzle in the first portion of the discharge duct is expediently disposed in the lateral wall of the discharge duct and/or in the sliding shoe. Said cleaning nozzle is preferably disposed such that it does not project beyond the wall of the discharge duct into the interior space of the discharge duct. Deposits are avoided on account thereof. If the cleaning nozzle is disposed in the sliding shoe, the former can also be disposed such that the cleaning jet in the adjacent peripheral region of the cleaning zone impacts the clothing such that the fluid and the contaminants can still be reliably discharged in the discharge duct. In one practical embodiment, at least two mutually opposite cleaning nozzles which are preferably offset in the running direction of the clothing are provided.
The fluid of the cleaning jet can comprise water and/or air and/or steam.
The first portion of the discharge duct can have a preferably adjustable aperture for delimiting the face of the receptacle opening.
As has already been addressed, the cleaning opening is preferably disposed so as to be substantially parallel with the clothing.
The discharge duct is expediently suctioned.
In one practical embodiment, the first portion of the discharge duct is followed by a further portion, wherein the further portion has a bend, and the discharging direction directly after the bend is directed away from the clothing.
According to one preferred practical refinement, propulsion jet nozzles are provided in the region of the bend of the further portion. The propulsion jet nozzles are preferably disposed such that the latter act in the discharging direction, preferably directly after the bend. This arrangement possesses a simple and cost-effective construction and enables energy to be incorporated across the entire cross section of the discharge duct directly after the bend. The propulsion jet nozzles are expediently disposed in a nozzle block which is connected to the discharge duct.
In one further variant of embodiment, additionally to the at least one cleaning nozzle, at least one blow down nozzle that is operated by a gaseous medium such as air, for example, can be disposed in the first portion of the discharge duct. On account thereof, the clothing after having been cleaned can be relieved of fluid of the at least one cleaning jet. The arrangement and the orientation of the blow down nozzle can be the same as with the cleaning nozzles.
The first and the further portion of the discharge duct are preferably made from tubes. The nozzle block can likewise have a cylindrical shape which preferably has the same diameter as the discharge duct. A compact, cost-effective construction mode that has a low tendency toward contamination is enabled on account thereof. This construction mode is also easy to clean.
The object is also achieved by a method for cleaning a continuously revolving clothing in a paper machine for producing and/or processing a paper, cardboard, or tissue web or another fibrous web. The method comprises the following steps:

- generating from a fluid at least one cleaning jet that is directed onto the clothing;
- providing a discharge duct;
- discharging the fluid and the dirt that is released from the clothing by the cleaning jet in a discharging direction;
- configuring a receptacle opening in a first portion of the discharge duct;
- configuring within the first portion of the discharge duct a cleaning opening that points toward the revolving clothing and forms a cleaning zone; and
- orienting the at least one cleaning jet toward the cleaning zone.

It is provided according to the invention that the receptacle opening is oriented counter to the running direction of the revolving clothing, and that the at least one cleaning nozzle is disposed such that the at least one cleaning jet, when viewed in the running direction of the clothing, in relation to the clothing plane impacts the clothing at an angular range of 20°<B<80°.
The present invention also relates to a paper machine mentioned at the outset, comprising at least one continuously revolving clothing and at least one device according to the invention for cleaning said clothing.
The device furthermore also relates to the use of a device according to the invention in the paper machine mentioned above.

Further features and advantages of the invention are derived from the description hereunder of preferred exemplary embodiments with reference to the drawing in which:

FIG. 1 shows an exemplary embodiment of a device according to the invention in a schematic and perspective illustration;

FIG. 2 shows a side view of the embodiment as per FIG. 1;

FIG. 2b shows a front view of the embodiment as per FIG. 1;

FIG. 3 shows a perspective illustration of a fragment of the embodiment as per FIG. 1;

FIG. 4 shows a front view of the embodiment as per FIG. 1 in a schematic illustration;

FIG. 5 shows a further perspective illustration of a fragment of the embodiment as per FIG. 1;

FIG. 6 shows a schematic illustration of the lower side of the sliding shoe; and

FIG. 7 shows a schematic illustration of a fragment of the embodiment as per FIG. 1, in the sectional plan view.

Equivalent elements in the figures have been identified by identical reference signs.
A device 1 according to the invention is shown in a schematic and perspective illustration in FIG. 1. The clothing 2 that is shown in fragments is a drying screen for drying a fibrous web in a drying section of a paper machine, said drying screen revolving in the running direction 9. The device 1 is connected to a traversing installation (not illustrated) and during the cleaning operation is reciprocated continuously or in intervals in the transverse direction 9.1. The entire revolving clothing 2 that in the region of the device 1 defines a clothing plane 2.1 can thus be cleaned. The device 1 comprises a discharge duct 5 which has a first portion 5.1. The latter is made from a tube and therefore has no rectangular or acute-angled corners in the interior. The tendency toward contamination is thus minor. The first portion 5.1 has a receptacle opening 6. The device 1 in relation to the drying screen 2 is disposed such that the receptacle opening 6 points counter to the running direction 9. The air barrier layers that are entrained by the drying screen thus pass the receptacle opening 6 at a velocity that is almost identical to the velocity of the drying screen. The first portion 5.1 of the discharge duct 5 has a cleaning opening 12 that points toward the drying screen 2 and forms a cleaning zone 13. In each case one cleaning nozzle 3, 3.1 is disposed laterally so as to be stationary in the wall of the first portion 5.1 of the discharge duct 5, said cleaning nozzles 3, 3.1 being disposed so as to be mutually offset in the running direction 9. In order to counteract any risk of contamination, the cleaning nozzles 3, 3.1 do not protrude into the discharge duct 5.1. The cleaning nozzles 3, 3.1 each deliver a cleaning jet 4 of cleaning fluid, in this example of water. The cleaning jets 4 meet on the drying screen 2 in the cleaning zone 13 and release contaminants. The latter, together with the cleaning fluid, are discharged in the discharging direction 8 from the cleaning zone 13 in the direction of the running direction 9 of the clothing 2, that is to say of the drying screen 2 in this example. The flow cross section of the first portion 5.1 of the discharge duct 5, beginning at the receptacle opening 6, increases in the discharging direction 8. Said flow cross section at the end possesses a circular cross section which is adjoined by a further portion of the discharge duct 5. This further portion is tubular and has a bend such that the discharging direction 8 in this portion changes such that the fluid and the released contaminants are guided away from the drying screen 2 in a discharging direction 8.1 after the bend for further treatment outside the paper machine. A nozzle block having propulsion jet nozzles 15 is disposed in the region of the bend such that the propulsion jet nozzles 15 are oriented in the direction of the discharging direction 8.1 after the bend, and act in this direction. The first portion 5.1 of the discharge duct 5 in the region of the cleaning opening 12 is assigned a sliding shoe 10, wherein the sliding shoe 10 surrounds the cleaning opening 12, that is to say that the sliding shoe 10 does not obscure the cleaning opening 12. The first portion 5.1 of the discharge duct 5 herein is connected to the sliding shoe 10 by welding or screw-fitting, for example. The sliding shoe 10 during the cleaning operation of the device 1 slides on the clothing, or has a minor spacing of less than 3 mm, preferably of less than 2 mm therefrom. On account of the direct contact with the clothing, or on account of the minor spacing from the clothing, the suction space of the first portion of the discharge duct is sealed in relation to the surroundings such that flows of air and fog that arise from the first portion are prevented or at least minimized. Contamination of the device 1 and the surroundings is reduced on account thereof. The sliding shoe 10 at the beginning in the running direction 9 of the clothing 2 has runners which run so as to be bent away from the drying screen, so as to guarantee a smooth run-up of the drying screen 2. At the same time, damage to the drying screen in the case of malfunctions and of an unstable running of the clothing is avoided on account thereof. The fluid that is reflected by the drying screen 2 and the released dirt are thus completely discharged. The discharge duct 5 is connected to a suction installation (not illustrated). Reliable discharging of the fluid and of the released contaminants is guaranteed on account thereof.
A side view of the embodiment as per FIG. 1 is schematically illustrated in FIG. 2. It can be seen that the flow cross section of the first portion 5.1 of the discharge duct 5, beginning at the receptacle opening 6, increases in the discharging direction 8. At the end, said flow cross section possesses a circular cross section which is adjoined by a further portion of the discharge duct 5. This further portion is tubular and has a bend such that the discharging direction 8 in this portion changes so that the fluid and the released contaminants from the drying screen 2 are guided away in a discharging direction 8.1 after the bend to further treatment outside the paper machine. A nozzle block 14 having propulsion jet nozzles 15 is disposed in the region of the bend such that the propulsion jet nozzles 15 are oriented in the direction of the discharging direction 8.1 after the bend, and act in this direction. It can also be readily seen that the entire cross section of the discharge duct 5 after the bend is impinged by the propulsion jet nozzles 15 on account of this arrangement. This results in a highly effective propulsion effect. The supply line 16 for the propulsion jet nozzles 15 is also integrated in the nozzle block 14. It can also be seen from this illustration that the cleaning opening 12 runs in a diverging inclined manner in relation to the discharging direction 8 which corresponds substantially to the profile of the centerline 5.2 of the discharge duct.
FIG. 2b shows a front view of the embodiment as per FIG. 1. Beyond the description of the device 1 to date, the exit of a propulsion jet nozzle 15 into the discharge duct 5 in the region of the bend can be seen here.
FIG. 3 shows a perspective simplified illustration of a fragment of the embodiment as per FIG. 1. The sliding shoe 10 is embodied without runners which however could likewise be applied in this example. The shape of the cleaning opening 12 can be identified in this illustration. Said cleaning opening 12 has a shape which steadily tapers in the discharging direction 8. Said cleaning opening 12 here has a parabolic shape. Since the cleaning opening runs so as to be parallel with the clothing plane and is in contact with the latter or is positioned at a minor spacing therefrom, contaminants that adhere to the drying screen 2 can thus be gently scraped off by the periphery 12.1 of the cleaning opening. The periphery 12 which surrounds the cleaning opening 12 of the first portion 5.1 of the discharge duct 5, or of the sliding shoe 10, that forms the cleaning zone 13 is provided with a slant such that a sharp edge is formed. The slant herein is embodied such that the face of the cleaning opening 12 increases in size toward the interior space of the discharge duct 5.1. This shape has proven advantageous in terms of discharging coarse contaminants that adhere to the clothing. On account of this geometry, the dirt is scraped from the clothing and discharged. Vibrations are thus also not created such as can be the case with a rectangular shape of the cleaning opening, since the air barrier layer and the contaminants herein abruptly meet at the end edge of the opening that extends across the width of the cleaning opening 12. The cleaning opening 12 begins at the receptacle opening 6 at the beginning of the discharge duct. The air barrier layer that is entrained by the drying screen 2 can thus makes its way unimpeded into the first portion 5.1 of the discharge duct 5 and into the open cleaning zone 13.
FIG. 4 shows a front view of the embodiment as per FIG. 1 in a schematic illustration. In this variant of embodiment, the cleaning nozzles 3, 3.1 are arranged in the sliding shoe 10. As a result of the impulse of the cleaning jet 4, the drying screen 2 is somewhat raised from the sliding shoe 10. The cleaning jets 4 impact the drying screen 2 somewhat outside the cleaning opening 12. The cleaning zone 13 in this case is larger than the cleaning opening 12. The cleaning zone 13 can thus also include that region that is close to the periphery and is adjacent to the cleaning opening 12, as long as the fluid and the released dirt can be reliably discharged in the discharge duct 5. The reflected cleaning jets 4 are illustrated in dashed lines and are entirely received by the first portion 5.1 of the discharge duct 5 and discharged in a discharging direction 8. The cleaning jets 4 possess a velocity component in the transverse direction and are inclined in relation to the clothing 2. By virtue of the woven structure, a very good cleaning effect is achieved on account of the velocity component in the transverse direction in particular in the cleaning of drying screens. The angle B in relation to the clothing plane 2.1 in this example is 40°. The angle A in relation to the transverse direction can be in the range between −45° and +45°, as can be seen from FIG. 7. The cleaning jet 4 in this example is oriented exactly in the transverse direction, that is to say that said cleaning jet 4 has no velocity component in the running direction 9. The angle A is thus 0°.
FIG. 5 shows a further perspective illustration of a fragment of the embodiment as per FIG. 1. The first portion 5.1 of the discharge duct 5 in this example possesses an aperture 7 which reduces the cross section of the first portion 5.1 of the discharge duct 5 at the beginning. The receptacle opening 6 is thus smaller than the cross section of the first portion 5.1 of the discharge duct 5 at the beginning. The aperture 7 can be fixedly connected to the discharge duct 5. However, it is also possible for said aperture 7 to be embodied so as to be adjustable. The flow conditions can be optimized on account thereof.
A schematic illustration of the lower side of the sliding shoe 10 is shown in FIG. 6. Said lower side in the region of the cleaning opening 12 has grooves 11 which can run so as to be rectilinear or curved, as is illustrated in an exemplary manner on the right and the left. The grooves 11 extend in the running direction of the clothing, from the beginning of the sliding shoe 10 up to the cleaning opening 12. On account of this arrangement, the grooves 11 are perfused by the air barrier layer that is entrained by the drying screen 2, and thus makes its way into the first portion 5.1 of the discharge duct 5. This has the effect of sealing and rinsing the periphery of the cleaning opening 12. Overall, this leads to a lower tendency towards contamination of the device 1 on the external side as well as on the internal side.
FIG. 7 shows a schematic illustration of a fragment of the embodiment as per FIG. 1 in the plan view and in sectional form in the region of the first portion 5.1 of the discharge duct 5. In each case one cleaning nozzle 3, 3.1 is disposed in the lateral wall of the first portion 5.1. The cleaning nozzles 3, 3.1 do not protrude into the interior space of the first portion 5.1. The cleaning jets 4 generated impact the drying screen 2 within the cleaning opening 12. The impact points are illustrated as circles. The cleaning jets 3, 3.1 in this example have different directions in relation to the transverse direction 9.1 and, when viewed in a plane that is parallel with the clothing plane 2.1, are established by the respective angle A between the cleaning jet 3, 3.1 and a line that runs parallel with the transverse direction 9.1. The angle A can be between −45° and +45°, wherein the cleaning jet 4 in the case of positive angles possesses a velocity component in the running direction, and the cleaning jet 4 in the case of negative angles possesses a velocity component counter to the running direction 9. In one preferred embodiment, this can be the angle A=0°. The direction of the cleaning jets 3, 3.1 in relation to the clothing is thus established by a solid angle which is defined by the angle A and by the angle B shown in FIG. 4.

LIST OF REFERENCE SIGNS

1 Device
2 Clothing
2.1 Clothing plane
3 Cleaning nozzle
3.1 Cleaning nozzle
4 Cleaning jet
5 Discharge duct
5.1 First portion of the discharge duct
5.2 Centerline of the discharge duct
6 Receptacle opening
7 Aperture
8 Discharging direction
8.1 Discharging direction after bend
9 Running direction of the clothing
9.1 Transverse direction
10 Sliding shoe
11 Grooves
12 Cleaning opening
12.1 Slanted periphery
13 Cleaning zone
14 Nozzle block
15 Propulsion jet nozzle
16 Supply line
A Angle
B Angle

Claims

1-16. (canceled)

17. A device for cleaning a clothing having a continuously revolving running direction along a clothing plane in a machine for at least one of producing or processing a paper, cardboard, tissue web or other fibrous web, the device comprising:

at least one cleaning nozzle for generating at least one cleaning jet from a fluid, said at least one cleaning jet being directed onto the clothing and impacting the clothing in a region of a cleaning zone;

said at least one cleaning nozzle providing said at least one cleaning jet with a velocity component in a direction transverse to the running direction of the clothing;

said at least one cleaning nozzle causing said at least one cleaning jet to impact the clothing at an angular range of 20°<B<80° relative to the clothing plane along the running direction of the clothing;

a discharge duct for discharging the fluid and dirt released from the clothing by said at least one cleaning jet in a discharging direction;

said discharge duct having a beginning and a first portion with a receptacle opening at said beginning of said discharge duct, said receptacle opening pointing counter to the running direction of the revolving clothing; and

said first portion of said discharge duct having a cleaning opening pointing toward the revolving clothing and forming said cleaning zone.

18. The device according to claim 17, wherein said angular range is 30°<B<70°.

19. The device according to claim 17, wherein said at least one cleaning nozzle causes said at least one cleaning jet to impact the clothing at an angular range of 45°<A<45° relative to the transverse direction.

20. The device according to claim 17, which further comprises a sliding shoe surrounding said cleaning opening and being associated with said first portion of said discharge duct in a vicinity of said cleaning opening.

21. The device according to claim 20, wherein said sliding shoe slides on the clothing.

22. The device according to claim 17, wherein said first portion of said discharge duct has a flow cross section increasing, decreasing, or being consistent in said discharging direction.

23. The device according to claim 17, wherein at least said first portion of said discharge duct has a flow cross section with exclusively rounded corners.

24. The device according to claim 17, wherein at least said first portion of said discharge duct has a flow cross section being tubular or made from a tube.

25. The device according to claim 17, wherein said first portion of said discharge duct has a centerline, and said cleaning opening has a face being inclined relative to said centerline in said discharging direction.

26. The device according to claim 25, wherein said first portion of said discharge duct is tubular, and said face of said cleaning opening diverges from said centerline.

27. The device according to claim 17, wherein said cleaning opening has a shape tapering or steadily tapering or tapering corresponding to a parabolic shape in said discharging direction.

28. The device according to claim 17, wherein said first portion of said discharge duct has a lateral wall, and said at least one cleaning nozzle is disposed in said lateral wall.

29. The device according to claim 20, wherein said at least one cleaning nozzle is disposed in said sliding shoe in a vicinity of said first portion of said discharge duct.

30. The device according to claim 26, wherein said at least one cleaning nozzle causes said at least one cleaning jet to impact a peripheral region adjacent said cleaning zone.

31. The device according to claim 17, wherein said at least one cleaning nozzle includes at least two mutually opposite cleaning nozzles.

32. The device according to claim 31, wherein said at least two mutually opposite cleaning nozzles are offset in the running direction of the clothing.

33. The device according to claim 17, wherein said receptacle opening has a face, and said first portion of said discharge duct has an aperture for delimiting said face of said receptacle opening.

34. The device according to claim 33, wherein said aperture is adjustable.

35. The device according to claim 17, wherein said discharge duct has a further portion downstream of said first portion of said discharge duct, said further portion has a bend, and said discharging direction is directed away from the clothing downstream of said bend.

36. The device according to claim 35, which further comprises propulsion jet nozzles disposed in a vicinity of said bend of said further portion, said propulsion jet nozzles acting in said discharging direction downstream of said bend.

37. A method for cleaning a clothing continuously revolving in a running direction along a clothing plane in a machine for at least one of producing or processing a paper, cardboard, tissue web or other fibrous web, the method comprising the following steps:

providing a discharge duct having a first portion;

forming a cleaning opening within the first portion of the discharge duct, the cleaning opening pointing toward the revolving clothing and forming a cleaning zone;

forming a receptacle opening in the first portion of the discharge duct and orienting the receptacle opening counter to the running direction of the revolving clothing;

using at least one cleaning nozzle to generate at least one cleaning jet from a fluid;

orienting the at least one cleaning jet toward the cleaning zone;

directing the at least one cleaning jet onto the clothing to impact the clothing at an angular range of 20°<B<80° relative to the clothing plane in the running direction of the clothing; and

using the cleaning jet to discharge the fluid and dirt being released from the clothing in a discharging direction.