EP0817884B1 - Cleaning device - Google Patents

Abstract

The invention pertains to a device for cleaning a circulating conveyor belt in a paper machine, for example a wet or dry screen belt or a felt band, with at least one nozzle that can be directed towards the fabric belt to apply air or liquid to the fabric belt. The device is designed with a suction chamber (18) that cooperates with the nozzle (8) and is situated so that the spray of dirt loosened from the conveyor belt (4) by the jet (12) and/or water spray or residual water can be sucked into and discharged from the suction chamber (18).

Description

The invention relates to a device for cleaning a conveyor belt at a Paper making machine, for example an endless one circulating dry or wet sieve or a felt, with at least one directed against the conveyor belt, especially in the direction transverse to the conveyor belt movable nozzle for loading the conveyor belt with air or liquid.

Numerous conveyor belts are used in paper machines, especially fabric tapes used. In the course of These conveyor belts operate the paper machine contaminated; Meshes or pores of these tapes become Example of paper fibers, adhesives or others Additives added. To make it work properly the conveyor belt, especially in the dryer section the paper machine to ensure it is necessary cleaning the conveyor belt.

A cleaning device that can be used at the beginning mentioned type is known from G 92 08 909.7 U1. The thought was already in this publication voiced, movable transversely to the direction of travel of the conveyor belt Arrange spray nozzles additionally rotatable, see above that the jet is not just due to a linear trajectory the movability transversely to the running direction of the conveyor belt describes, but that this linear movement a circular movement is also superimposed.  

The advantage of such a cleaning device is that on the conveyor belt to be cleaned sprayed liquid more evenly and on one applied larger area of the conveyor belt can be. In other words: the rotating nozzle rather than a linear one wide strip-shaped area of the conveyor belt. It So it is better possible to evenly clean the entire area of the circulating conveyor belt guarantee.

In the known cleaning device, the conveyor belt is acted upon by deflection liquid after deflection by 180 ° from above and from the side opposite the transport side. The rotatable nozzles are thus arranged within a loop guide of the endless conveyor belt. Below the conveyor belt, collecting troughs are provided for receiving and removing cleaning fluid and detached contaminants. In this device, however, splash water or dirty water is formed as a result of the liquid jet emerging from the rotating spray nozzle at high pressure and hitting the conveyor belt. It also proves to be disadvantageous that water remains in the fabric of the conveyor belt, which leads to the rewetting of the paper web that comes into contact with the rotating conveyor belt a little later. This can lead to disruptions in the production process, particularly in the case of paper webs with grammages of less than 50 g / m ² .

Although it has already been proposed, a cleaning device a blow-out device with liquid nozzles order, in which the liquid in the fabric band is blown out with compressed air. This solution however, there is the disadvantage that splashing water   or water mist formation, which in turn leads to humidification of the paper web or the paper machine. Also a known steam blower with one on the same suction device downstream of the fabric belt does not produce satisfactory results (DE 43 22 565 A1).

A cleaning device is known from WO 94/12 349 A1 for printing rollers or conveyor belts for paper machines that one with a pressurized liquid acted upon spray nozzle comprising a Suction nozzle is surrounded. The one coming out of the spray nozzle Jet stream can be directed against the surface to be cleaned become, whereby the adhering to the surface Soiling is removed and removed using the suction nozzle the cleaning area. For enlargement In the cleaning area, the spray nozzle can be traversed educated.

DE 25 48 432 A1 discloses a cleaning device that several on radial arms rotatable about an axis arranged cleaning nozzles comprises. It has shown, that not a desired cleaning result in all cases is achievable.

The invention is therefore based on the object of a cleaning device of the kind mentioned at the beginning to improve that the disadvantages mentioned do not occur that the device is compact and particularly economical Can be manufactured in a manner that is reliable can be used.

To solve this problem, a cleaning device proposed, which has the features of claim 1. This includes at least one against a conveyor belt a paper making machine directional nozzle for loading   this conveyor belt with a liquid or with air. Furthermore, one cooperates with the nozzle Suction chamber provided, which is assigned to the nozzle in this way is that through the jet from the conveyor belt Detached dirt and / or water mist or residual water on the preferably shortest possible route into the suction chamber can be sucked in and discharged. Besides, is provided that the nozzle relative to the surface normal of the conveyor belt inclined transversely to the direction of belt travel is traversable. The cleaning device draws is characterized in that the nozzle rotates about an axis is trained. By overlaying a translation and rotational movement of the nozzle on the Conveyor belt adhering dirt under different Directions of the medium jet emerging from the nozzle met. This is a particularly thorough one Detachment of the dirt is possible, in addition due to the inclination of the nozzle relative to the surface normal the conveyor belt is improved. The at an angle the transport jet hits the transport jet reflected, forming a water mist in which the dirt detached from the conveyor belt is solved, so that this together with the residual water especially applied thoroughly from the cleaning area can be.

To solve the problem, a device with the Features of claim 2 proposed. The cleaning device is characterized in that the nozzle one Has nozzle diameter that is less than 0.3 mm and / or pressurized with a medium is that under a pressure of 100 bar to 1000 bar, preferably from 150 bar to 300 bar. By the relatively small nozzle diameter can be used for Cleaning the conveyor belt required amount of liquid   be kept low, which on the one hand is economical There are advantages and humidification the conveyor belt is reduced so that on a drying device downstream of the cleaning device can be dispensed with for the conveyor belt. Due to the high pressure of the cleaning medium even strongly adhering soiling is safely removed become.

In a preferred cleaning device, the suction space from a suction cup surrounding the nozzle in the form of a jacket educated. This way it becomes compact and integral design of a combined nozzle and suction device reached. The suction cup can preferably of an essentially cylindrical casing of the nozzle, which, as is known per se, cross traversed on the conveyor belt. Instead of one a circular cross-section can also be a elliptical or oval shape can be provided. It can the nozzle or the nozzle head against the direction of the belt Arrange eccentrically to the sheathing.

In a preferred embodiment of the invention the suction cup on its facing the conveyor belt End area is particularly bell-shaped or conical expanding. This will make the surface area of the conveyor belt from the suction cup or is detected by the suction chamber, enlarged.

In a further embodiment of the cleaning device are several inclined in different directions Nozzle provided; these cannot rotate in the traversing suction cup. Preferably is at least a rotating and inclined one Nozzle provided, as a result of which the jet of jet on Conveyor belt can better detach adhering dirt.  

Because of the rotation of the nozzle, one is made up of different ones Directions of cleaning impulse hitting the conveyor belt to disposal. It has been shown that the Most effective cleaning effect in the rotation area is in which the nozzle or the nozzle jet is a speed component opposite to the direction of travel of the conveyor belt having. It is therefore suggested in the other section where the rotatable Jet jet directed in the running direction of the conveyor belt Has speed component, the nozzle to deactivate fluidically. For this a Aperture can be provided that impinges the jet prevented. But it can also, with regard to economic water consumption in an advantageous manner section feedable nozzle feed lines are provided be. At this point it should also be noted that instead of a rotatable nozzle, a rotatable nozzle head can be provided with several nozzles from which one or more nozzles as driving nozzles for rotating drive of the nozzle head can be formed. Possible it is also to provide at least one additional nozzle, whose outflow direction runs away from the conveyor belt, which is used only for the rotation drive.

To generate a negative pressure in the suction chamber, in Further training proposed the invention, a with the suction chamber fluidly connectable compressed air injector to provide.

With regard to the most effective suction it turned out to be particularly advantageous if the Opening of the suction cup facing the conveyor belt to the surface profile the conveyor belt or the cylindrical shape a roller over which the conveyor belt is guided, is adapted.  

According to a development of the invention, the nozzle material Diamond, ruby or ceramic materials are used.

Figur 1

eine Ausführungsform der erfindungsgemäßen Reinigungsvorrichtung;

Figur 2

einen Schnitt durch einen bei der Vorrichtung nach Figur 1 verwendbaren Düsenkopf;

Figur 3

eine Ansicht des Düsenkopfes nach Figur 2 von unten.

Figur 4

einen Teilschnitt der erfindungsgemäßen Reinigungsvorrichtung gemäß einem weiteren Ausführungsbeispiel;

Figur 5

eine Draufsicht der Reinigungsvorrichtung gemäß Figur 4;

Figur 6

einen Schnitt durch eine Reinigungsvorrichtung gemäß einem weiteren Ausführungsbeispiel, und

Figur 7

eine schematische Darstellung einer Trokkenpartie mit den erfindungsgemäßen Reinigungsvorrichtungen.

Further features, details and advantages of the invention result from the attached drawing and from the following description of various advantageous embodiments of the cleaning device according to the invention. The drawing shows:

Figure 1

an embodiment of the cleaning device according to the invention;

Figure 2

a section through a nozzle head usable in the device of Figure 1;

Figure 3

a view of the nozzle head of Figure 2 from below.

Figure 4

a partial section of the cleaning device according to the invention according to a further embodiment;

Figure 5

a plan view of the cleaning device according to Figure 4;

Figure 6

a section through a cleaning device according to another embodiment, and

Figure 7

is a schematic representation of a dryer section with the cleaning devices according to the invention.

Figure 1 shows an embodiment of the cleaning device 2, for cleaning a dryer belt 4 in Area of a roller 6 of a paper machine, not shown is arranged. The cleaning device 2 comprises a rotor nozzle 8 with a rotatable nozzle head 10, which has a nozzle arrangement, not shown. This nozzle arrangement can be one or more tangential outflowing driving nozzles to generate a rotational movement in the range of 2000 - 3000 revolutions per Minute and one or more cleaning nozzles, which serve to act on the dryer fabric 4.

Furthermore, a cylindrical suction bell 14 is provided, which surrounds the nozzle 8 and the nozzle head 10. The The interior of the suction bell 14 is fluid with a suction line 16 connected, and forms one associated with the nozzle Suction chamber 18.  

The cleaning device 2 comprises an energy chain for the media supply, of which only one with one High pressure pump connectable high pressure hose 20 for supply the nozzle with liquid in a pressure range of preferably 150 bar - 300 bar and the suction line 16 for removing splash water or water mist with dirt particles from the suction chamber 18 bound therein is shown.

The device components of the Cleaning device 2 are on a traversing carriage 11 in a direction transverse to the running direction of the dryer fabric 4 arranged displaceably. The traversing carriage 11 sits here on cross members 12 and is of a not shown Traverse motor with a predeterminable speed drivable, the traversing speed is usually in the range of 3 m / min.

As can be seen from FIG. 1, one is the dryer fabric 4 facing end portion 22 of the suction cup 4 adapted circular cylindrical circumferential shape of the roller 6, so that between the suction cup 14 and the dryer 4 certain adjustable distance or gap guaranteed is along the edge 24 of the end portion 22 in the is essentially constant.

When operating the cleaning device, the rotor nozzle is 8 or the nozzle arrangement in the nozzle head 10 with Cleaning fluid, especially with high pressure standing water, applied via the high pressure hose 20. The nozzle head 10 with the nozzle arrangement is thereby by the recoil effect of propelling nozzles in a rotational movement transferred. This describes the liquid jet which is at a certain angle to the longitudinal axis of the nozzle 26 inclined cleaning nozzle a conical Lane 27 and thus meets the at an angle   Dryer screen 4 and thus removes the impurities from its surface. By overlaying the traversing movement and the rotational movement of the cleaning nozzle the dirt particles under different directions hit by the liquid jet of the cleaning nozzle and can be removed more easily than when in use one running parallel to the longitudinal axis direction 26 Jet. Due to the inclination of the cleaning nozzle respectively the liquid jet is also caused to the impinging jet of liquid into the suction space 18 is reflected and the resulting water mist with dirt particles bound therein as well as residual water can be discharged via the suction line 16. It there is a suction effect represented by the arrows or current. Around the suction cup 14 therefore there is no splashing water, dirt or water leakage can be largely avoided. As It has proven to be particularly advantageous if the Negative pressure in the suction chamber 18 and the suction line 16 is generated by means of a compressed air injector. Has further it turned out to be advantageous if the negative pressure in the suction chamber 18 is changeable and thus different Operating conditions can be adjusted.

In Figures 2 and 3 is a rotatable nozzle head 10 corresponding nozzle head 10 'in different views shown. The nozzle head 10 'is by means of a Bearing 28 rotatably held on a flange 30. in the Inside the flange 30 is a fixed nozzle feed line 32 provided which opens into a pressure chamber 34, whose walls 36 against the inside of a cylindrical Component 38 but sealingly but slidably. The cylindrical component 38 has four at an angle of Openings arranged at 90 ° to each other. There are Nozzle feed lines 40 connected radially after extend outside and preferably in its end portion   Are bent 90 °, as can be clearly seen in FIG is. The nozzle feed lines 40 finally end in inclined cleaning nozzle end areas 42. The likewise The proposed driving nozzles are not shown. How to Figures 2 and 3 can also be seen is always only one of the nozzle feed lines 40 is pressurized, while the remaining nozzle feed lines 40 are depressurized. The pressure chamber 34 is now oriented so that the liquid jet one of the running direction of the dryer 4 opposite Has speed component, so that the cleaning effect is particularly high. So are the nozzles, the liquid jet of which is a component of velocity in the running direction of the dryer fabric 4 would have in view of low water consumption depressurized and therefore deactivated.

The cleaning nozzles are for a pressure range of 150 bar - 300 bar and have a nozzle diameter from 0.3 mm. As the nozzle material preferably sapphire or ceramic materials used.

In Figures 4 and 5 is a second embodiment a cleaning device shown schematically. This corresponds essentially to that with reference 1 to 3 cleaning device described, which is why a further explanation of the matching Parts is dispensed with. There is a difference the oval cross-sectional shape of the suction cup 14, wherein the Nozzle head 10 eccentrically opposite to the direction of tape travel (arrow P) is arranged. This will improve Extraction effect on the water mist (loaded with dirt) exercised.

Another difference of this cleaning device compared to that shown in Figure 2 is that no pressure chamber 34 is provided. The water supply line 32   is with all four nozzle feed lines shown in Figure 5 40 connected. So all four nozzle inlets are 40 pressurized.

Between the nozzle head 10 and dryer fabric belt 4 is one Aperture 61 is provided, the outermost edge 63 of which is angled is. This edge 63 serves as a fastening edge for webs 65, which in turn is connected to the inner wall of the suction bell 14 are connected. Between the individual webs 65, the Suction cup wall 14 and the aperture edge 63 are openings or column 67 formed over the one Connection from the suction chamber 18 to the outside occurs.

The aperture 61 has an opening 69 which is in the Effective area of the rotating cleaning nozzles 71 is located. The dimensioning and position of this breakthrough 69, in particular in the circumferential direction of the diaphragm 61, is so chosen that always at least one cleaning nozzle 71 this Range passes, here the jet direction the tape running direction (arrow P) is opposite.

Thus, according to the function described above the pressure chamber 34, in any case, achieves that only one Cleaning nozzle 71 acts on the dryer fabric belt 4. The three further cleaning nozzles shown in FIG also, but the liquid jet hits not on the dryer belt 4 but on the screen 61. This liquid is sucked into the suction chamber 18, as indicated by the arrows shown in FIG. 4, the edge 63 of the diaphragm 61 additionally has a deflecting function comes to.

The liquid mist reflected by the dryer fabric belt 4 is either through the aperture 69 or through the previously mentioned gap 67 sucked into the suction chamber 18.  

The rotor head 10 is driven as in the first Exemplary embodiment, via nozzles 73. FIG. 4 shows it can be seen that these nozzles 73 are oriented such that the flowing medium is an axial flow component has that of the axial component of the liquid jet is opposite. This can be a compensation the axial recoil forces, resulting in a Relief of the bearing 28 leads.

However, the cleaning process itself corresponds to that in Described in connection with Figures 1 to 3. Therefore should not be discussed further here become.

Figure 6 shows another embodiment of a cleaning device according to the invention, but in the no rotating cleaning nozzles are provided. Much more the cleaning nozzles 81 are fixed to the suction cup 14 connected. The cleaning nozzles 81 are in the middle the suction bell 14 aligned so that the liquid jets 83 preferably hit at one point, opposite the opening area of the suction bell 14 lies. If this point is directly on the conveyor belt, a point-like application is achieved. Will the Distance of the nozzles to the conveyor belt changed, shifted also the intersection of the liquid jets. Out the point-like then becomes a flat-shaped application.

The liquid mist bouncing off the dryer belt 4 is - as in the previous cases - in the suction room 18 sucked in. The suction effect is enhanced by the below the nozzles 81 continued suction bell, the ends very close to the conveyor belt. By between the suction bell 14 and the conveyor belt 4 formed   Gap 85 flows air that the liquid mist carries with it.

As in the previously described exemplary embodiments explained, the cleaning nozzles 81 are aligned so that in the direction of movement of the dryer fabric 4th directed component is as low as possible.

Although only three cleaning nozzles 81 are shown in FIG can also have more than three such cleaning nozzles be provided.

FIG. 7 schematically shows a section of a drying section shown, with two single-tier dryer groups 91 and 93 are indicated. Each of these two drying groups 91 and 93 is made up of several in a known manner Drying cylinders 95 and guide rollers 97 together. Drying cylinder 95 and deflecting rollers 97 are arranged that the paper web alternately drying cylinder and Deflection rollers pass and the dryer section meanders goes through.

Each dryer group 91 and 93 is a dryer fabric belt 4 assigned to the at the beginning of each drying group Paper web runs up and at the end of the drying group again is removed and returned.

From Figure 7 it can be seen that one cleaning device each 2 cooperates with a dryer fabric belt 4. The two cleaning devices 2 are each on a dryer fabric guide roller 6 in the initial area of the return of the dryer fabric belt 4 arranged. So you can achieve that stuck on the dryer fabric belt 4 Cleaning fluid can evaporate before that Dryer screen belt again in contact with the paper web is coming. Also the guide rollers following the roller 6 Return to remove liquid from the   Dryer fabric belt 4 at, once through the in each "Auflaufzwickel" arising overpressure and to the other which when running around the roller onto the liquid particles centrifugal force exerted.

Claims (18)

1. Apparatus for the cleaning of a transport belt of a paper making machine, for example of a dryer screen, belt or wet screen belt or of a felt belt, comprising at least one nozzle (8) which can be directed towards the transport belt (4) to act on this transport belt (4) with air or liquid, wherein a suction space (18) cooperating with the nozzle (8) is provided, which is associated with the nozzle (8) in such a way that contamination, mist and/or water mist or residual water released from the transport belt (4) by the nozzle jet can be sucked into the suction space (18) and led away, and wherein the nozzle (8) is inclined relative to the surface normal of the transport belt (4) and is traversable transverse to the belt running direction, characterized in that the nozzle (8) is made rotatable about an axis.
2. Apparatus for the cleaning of a transport belt of a paper making machine, for example of a dryer screen, belt or wet screen belt or of a felt belt, comprising at least one nozzle (8) which can be directed towards the transport belt (4) to act on this transport belt (4) with air or liquid, wherein a suction space (18) cooperating with the nozzle (8) is provided, which is associated with the nozzle (8) in such a way that contamination, mist and/or water mist or residual water released from the transport belt (4) by the nozzle jet can be sucked into the suction space (18) and led away, in particular in accordance with claim 1, characterized in that the nozzle (8) has a nozzle diameter which is smaller than 0.3 mm and/or is acted on by a pressurised medium which stands under a pressure of 100 bar to 1000 bar, preferably of 150 bar to 300 bar.
3. Apparatus in accordance with claim 2, characterized in that the nozzle material is diamond, ruby or ceramic material.
4. Apparatus in accordance with one of the preceding claims, characterized in that the cleaning apparatus (2) is arranged in the initial region of the return run of the transport belt (4).
5. Apparatus in accordance with one of the preceding claims, characterized in that the cleaning apparatus (2) is arranged in the region of a roll (6).
6. Apparatus in accordance with one of the preceding claims, characterized in that the suction space (18) is formed by a suction bell (14) which surrounds the nozzle (8) in jacket-like manner.
7. Apparatus in accordance with claim 6, characterized in that the suction bell (14) has a rubber jacket or brushes.
8. Apparatus in accordance with one of the preceding claims, characterized in that the end region (22) of the suction bell (14) which forms the transport belt side opening of the suction bell (14) is matched to the surface shape of the transport belt (4) or to the cylindrical shape of a roll (6).
9. Apparatus in accordance with one of the preceding claims, characterized in that the transport belt side end region (22) of the suction bell (14) is made so that it diverges in the direction towards the transport belt (4).
10. Apparatus in accordance with one of the preceding claims, characterized in that the transport belt side end region (22) of the suction bell (14) projects beyond the nozzle (8) in the direction towards the transport belt (4).
11. Apparatus in accordance with one of the preceding claims, characterized in that the nozzle (8) is made rotatable about an axis.
12. Apparatus in accordance with claim 11, characterized in that the rotatable nozzle (8) is inclined towards the axis of rotation (26).
13. Apparatus in accordance with one of the preceding claims, characterized in that the nozzle (8) is inactive from a technical flow viewpoint in a section in which the nozzle jet of the nozzle (8) has a speed component pointing in the direction of movement of the transport belt (4).
14. Apparatus in accordance with claim 12, characterized in that a diaphragm is provided for the screening of the nozzle (8) in the section with a speed component of the nozzle jet directed in the running direction of the transport belt (4).
15. Apparatus in accordance with claim 12, characterized by nozzle feed lines (40) which can be activated section-wise.
16. Apparatus in accordance with one of the preceding claims, characterized by a rotatable nozzle head (10) having a plurality of nozzles.
17. Apparatus in accordance with one of the preceding claims, characterized by an oval or elliptical cross-section of the suction space (18).
18. Apparatus in accordance with claim 17, characterized in that the suction space cross-section extends in the band running direction (arrow P), and in that the nozzle (8) or the nozzle head (10) is eccentrically arranged in the suction space (18) opposite to the belt running direction.