DE102008000178A1 - Suction device for a machine producing a fibrous web - Google Patents

Abstract

The invention relates to a suction device (1) for a machine producing a fibrous web (2), comprising a suction roll (3) having a suction roll diameter (D.3) with a roll tube (4) having a load bearing roller tube diameter (D.4) and with a supporting structure (5) arranged around the load-bearing roller tube (4), which is both permeable to air and carries a conveyor belt (6) with fibrous web (2) lying thereon and to be drained in a wrapping area (7), and an external suction box (10) which partially surrounds the suction roll (3) from the outside and which forms the conveyor belt (6) and thus the fibrous web (2) to be drained with an external negative pressure (pU) generated by at least one vacuum source (11) connected to the suction box (10). acted upon, wherein at least one annulus (13) between the supporting roller tube (4) of the suction roll (3) and the outer, the conveyor belt (6) carrying portion (12) of the support structure (5) the suction roller (3) is present, so that on this with the external suction box (10) generated negative pressure (pU) on the on the support structure (5) in a wrap (7) resting conveyor belt (6) and thus at the fibrous web to be drained (2) can act. The suction device according to the invention is characterized in that the ratio of roller tube diameter (D.4) to Saugwalzendurchmesser (D.3)> = 0.75, preferably> = 0.80, in particular> = 0.85, is.

Description

The Invention relates to a suction device for a fibrous web, in particular paper or board web, producing machine, in particular A paper or board machine comprising a suction roll diameter having suction roll with a load-bearing and a roller tube diameter having roller tube and with a bearing around the roller tube arranged support structure, both air permeable is as well as a conveyor belt with lying on it and to be drained Wearing fibrous web in a loop area, and an external suction box that seals the suction roll from the outside partially encloses and the transport belt and thus the fibrous web to be dewatered with an external, of at least one vacuum source connected to the suction box produced negative pressure, wherein at least one annulus between the supporting roller tube of the suction roller and the outer, the conveyor belt bearing area of the support structure of Suction roll is present, so over this the with the external suction box created negative pressure on the on the support structure in a loop-lying conveyor belt and thus can act on the fibrous web to be drained.

at The conveyor belt may be, for example, a forming fabric act, wherein the suction device then in a wire section of a Machine for producing a fibrous web is arranged. Also It is basically possible for the conveyor belt as an inserted in a press section press felt or in a drying section used dryer fabric is formed. Either the press section as well as the dryer section provide this known manner a part of a machine for manufacturing a fibrous web.

Such a suction device with a suctioned from the outside roll is for example from the US patent US 2,270,464 known. The ratio of roller tube diameter of the roller tube to Saugwalzendurchmesser the suction roller is a maximum of 0.50 [-], so that a very large annular space between the supporting roller tube of the suction roller and the outer, the conveyor belt-bearing portion of the support structure of the suction roller is present. In order for the suction roll of the suction device to obtain the necessary carrying capacity for operation, the annular space is provided with a multiplicity of spaced and each having a multiplicity of apertures having annular disks. Depending on the thickness of the discs, these discs can lead to markings in the fibrous web to be drained and thus to quality losses. In addition, the annular discs can adversely affect the formation of a uniform negative pressure across the width. The most serious disadvantage of this suction device, however, seems to be that it is not suitable for use in a modern machine for producing a fibrous web, which is currently already being operated at a web speed of up to 2,200 m / min and possibly even more, due to its required size suitable. In a modern machine is only a limited space available, which is not sufficient for such a suction device in a necessary design, for example, in view of the required high inertia.

Another suction device with a suctioned from the outside roll is for example from the European patent EP 0 889 165 B1 known. The disclosed roller, which carries in a peripheral region a conveyor belt with a fibrous web resting thereon, is at least partially enclosed by an evacuated box. The roller tube is in this case perforated, so that the vacuum applied to the outside surrounding box can act on the conveyor belt and thus on the fibrous web.

One Disadvantage of perforated and externally drawn roller is that they are for applications in the wet end of a machine for producing a fibrous web as before, in particular due to corrosion reasons, from expensive Saugwalzenwerkstoffen must be made. Also drilling the variety of holes through the entire wall thickness of the roller tube, the necessary Carrying capacity, such as beam or shell bending, is enough, is a costly manufacturing process. For this reason, such a solution leaves no significant cost advantages over a conventional one Expect suction roller with internal suction box.

One Another disadvantage of the perforated and externally evacuated Roller is that her roller tube from the same loads String pulls and vacuum effect like a conventional one Suction roller experiences. As a result, the roller tube must also like be dimensioned at a conventional suction roll. Here too The many suction holes lead to a significantly reduced Stiffness, which also increases the roller, if the maximum allowable deformation is the sizing of Roller determined. In addition, the suction holes cause Notch stresses in the roll tube, which in strength-driven dimensioning also lead to a larger roller.

Furthermore, it is disadvantageous that the supporting material of the perforated and externally evacuated roll constantly corrosive operating conditions through the process media, such as sieve water, chemicals and the like, is exposed. The well-known steels have no fatigue strength under such conditions, not even the special corrosion-resistant suction roll steels. Depending on the level of corrosion load, sooner or later the suction roll tube will break. In addition, there is the risk of stress corrosion cracking due to the corrosive environment on the load bearing, loaded roller tube, which limits the choice of materials (insensitive to stress corrosion cracking), limits the permissible stresses and possibly leads to unexpectedly early failure of the roller tube due to breakage.

Of the Invention is based on the object, an improved suction device with an externally drawn roller, in particular the aforementioned To specify type, the disadvantages mentioned as far as possible, preferably avoided altogether. In particular, the roller tube should be cheaper can be produced and a higher load capacity have or additional measures to increase the carrying capacity.

These Task is in a suction device of the type mentioned solved according to the invention that the ratio of roller tube diameter to suction roller diameter ≥ 0.75, preferably ≥ 0.80, in particular ≥ 0.85. In this case, the roller tube diameter a value in the range of 500 to 2,000 mm, preferably 800 to 1,800 mm, assume.

The inventive object is in this way completely solved.

The Roller tube of the suction roll thus provides the advantage of a higher Load capacity at one, compared with the state of Technology, not deteriorated drainage quality the fibrous web to be drained over their Width away. In addition, the roller tube of the suction roller is no longer through Suction holes weakened and can be smaller in total Be dimensioned relative to the wall thickness. Further opened Such a suction device a variety of others, in operation advantageous options, such as a provision of special anti-corrosion measures, a realization further measures to increase sustainability or an improvement in tape properties.

In a first embodiment of the invention is provided that the annular space of the suction roll of at least one inner area of the support structure is formed and that the annulus in the circumferential direction of the suction roll without interruptions is or possible interruptions of the annular space in the circumferential direction the suction roll are spaced so far apart that the negative pressure effect on the conveyor belt and thus on the to be drained Fiber web not disturbed in the entire wrap or even stopped. Moreover, due to the stated Forming the annulus the carrying capacity of the suction roll further increased.

The air-permeable support structure is preferably made of a corrosion-resistant material, in particular a stainless steel, preferably an austenitic stainless steel or a ferritic-austenitic duplex steel, in particular with regard to their operating and environmental conditions, such as the process media. The austenitic stainless steel may comprise four main families: the molybdenum-free Cr-Ni steels, such as 1.4307, 1.4306 or 1.4301 according to DIN EN 10088/1 , the molybdenum-containing Cr-Ni-Mo steels such as 1.4401, 1.4404, 1.4432, 1.4435 or 1.4436 according to DIN EN 10088/1 , the high-alloyed special austenites and the manganese austenites. By contrast, the ferritic-austenitic duplex steel favorably has a carbon content of at most 1.2% by weight, preferably of not more than 0.10% by weight, in particular of not more than 0.030% by weight, a nitrogen content in the range from 0.05 to 0, 40 wt.%, In particular from 0.05 to 0.22 wt.%, A chromium content in the range of 20.0 to 30.0 wt.%, In particular from 21.0 to 24.0 wt.%, A nickel content in Range of 1.0 to 8.0 wt.%, In particular from 1.5 to 6.5 wt.%, And a molybdenum content in the range of 0.0 to 5.0 wt.%, In particular from 0.1 to 3 , 5% by weight, on.

Farther is the roller tube of the suction roll at its outer Surface preferably with a protective medium, such as a paint, a (spray) coating or a plating with corrosion-resistant sheet, provided to them in front of a to protect direct contact with the corrosive process media. Such measures also allow the use of materials with more favorable properties, in particular with regard to Cost and / or strength and / or rigidity. So can the roller tube the suction roll, for example, made of a non-corrosion resistant Material, in particular a structural steel, such as a St-37 or St-52.

In a first preferred embodiment, the outer region of the air-permeable support structure consists of at least one perforated and preferably thin-walled hollow cylinder. The perforations in the hollow cylinder can be produced inexpensively and reliably by means of drilling, punching, laser cutting or similar machining methods. In addition, the perforations can be made in various designs: they can have countersinks, they can Kings NEN have constant, converging or diverging cross-sectional shapes, and / or they may have different cross-sectional shapes, for example, in terms of their diameters and their courses. Of course, further, known to those skilled execution options are conceivable.

Also the perforated hollow cylinder can be made of a bent and assembled, in particular a welded sheet, preferably a Perforated sheet, consist. This practical possibility draws in particular by comparatively low production costs short production times.

in the Regarding the operational requirements in terms of strength and stiffness, it is favorable if the perforated hollow cylinder a wall thickness in the range of 0.5 to 8 mm, preferably from 1 to 6 mm, in particular from 2 to 5 mm. Moreover, provide Such thickness ranges noticeable weight savings, in particular with otherwise unchanged design criteria.

Farther it is beneficial if the outer area of the air permeable support structure of several along the roll length adjacently arranged hollow cylinder segments consists. This simplifies the one hand, the assembly of the suction roll, on the other hand the cost of smaller, especially easier to produce Components significantly reduced.

In a second preferred embodiment, the outer region of the air-permeable support structure consists of at least one honeycomb structure composed of upright bands, which has a multiplicity of honeycombs. Such a honeycomb structure, as is customary today in forming rolls, provides the advantage of low weight coupled with good stiffness values and ideal conditions for uniform negative pressure on the conveyor belt and the fibrous web resting thereon. Furthermore, such a honeycomb structure has a low marking effect on the conveyor belt and thus on the fibrous web to be dewatered. Such a honeycomb structure is for example from the German patent application DE 32 10 320 A1 The content of which is hereby made the subject of the present description.

Under Consideration of aspects of strength engineering the honeycomb structure preferably in or approximately in the circumferential direction the suction roll aligned longitudinal extent. Also The honeycomb of the honeycomb structure in the circumferential direction of Suction roll be offset from each other, so that the best possible planar support of the conveyor belt takes place.

in the With regard to the operational requirements in terms of carrying capacity it is advantageous if the honeycomb structure has a height in the Range of 3.0 to 25.0 mm, preferably from 4.0 to 20.0 mm, in particular from 5.0 to 15.0 mm. Moreover, such provide Altitude ranges significant weight savings, in particular with otherwise unchanged design criteria.

In Another preferred embodiment is the inner one Area of the air-permeable support structure in the longitudinal direction of the suction roll spaced supports, such as upright rings or honeycombs, or spacers, such as pins formed, all of which are part of the air-permeable Support structure are. Such a trained inner Ensured area of the air-permeable support structure to a sufficient extent that the negative pressure effect on the Conveyor belt and thus on the fibrous web to be drained not disturbed in the entire looping area or even prevented.

The Supports or spacers are preferred to theirs inner ends suitably connected to the supporting roller tube. The compound can in this case, for example, by shrinking the air permeable support structure on the supporting Roller tube done.

in the With regard to the operational requirements in terms of carrying capacity It is favorable if the inner area of the air-permeable Support structure a height in the range of 5.0 to 50.0 mm, preferably from 10.0 to 40.0 mm, in particular from 15.0 to 30.0 mm. Moreover, provide such height ranges Significant weight savings, especially in otherwise unchanged Design criteria.

Also, in another preferred embodiment, the suction roll may further include at least one additional means for supporting the supporting roll tube over its length to thereby increase its carrying capacity and minimize any deformations. The additional device preferably comprises a supporting and static yoke, which extends through the entire supporting roller tube and is statically supported at its two ends in the racks of the machine. The supporting roller tube can in turn be supported by a plurality of hydrostatic elements on the supporting and static yoke, wherein the hydrostatic elements are preferably adjustable, in particular controllable / regulated. Such an additional device is for example from the German patent application DE 25 55 677 A1 whose contents are hereby the subject of the present description is made.

In an alternative and preferred embodiment, the additional means may comprise a second rotating roller tube which extends through the first supporting roller tube and is connected to the first supporting roller tube only in the roller center. The second rotating roller tube is in this case preferably rotatably mounted at its two ends, preferably via pins, in the racks of the machine. Such an additional device is for example from the German patent application DE 101 12 202 A1 The content of which is hereby made the subject of the present description.

Furthermore, in a further preferred embodiment, at least one further suction box may be provided on the suction device, which adjoins the first suction box and pressurizes the fibrous web to be dewatered with negative pressure via the conveyor belt. By this at least one further suction box a stable and rigid support body is created, which provides sufficient stability for supporting a sealing strip in the gusset area even with very wide machines for producing a fibrous web. Furthermore, the suction zone is extended by the at least one further suction box in such a way that a continuous and uninterrupted Gesamttsaugzone arises, whereby the suction effect is significantly improved overall. This is in contrast to the arrangement of one of the suction roll at a distance from this arranged insulated suction box, whereby no such effective suction can be achieved. The provision of at least one further suction box is, for example, from the already mentioned European patent specification EP 0 889 165 B1 The content of which is hereby made the subject of the present description.

moreover can according to another embodiment the first suction box as the central, the suction roll from the outside be formed partially enclosing suction box, the extends from the inlet gusset to the outlet gusset, wherein seen in the web running direction in front of the suction roller, a second suction box is arranged, which extends to the first suction box and which is sealed against the conveyor belt, and wherein in the web running direction seen after the suction roll, a third suction box is arranged, which extends to the first suction box and the against the conveyor belt is sealed. This is a special way strong negative pressure on the conveyor belt or to be drained Transfer fibrous web. Furthermore, can be a Better adaptation of the vacuum to the specific operating conditions reach, since the respective suction boxes either with the same negative pressure or with different suppressions can be operated. This can be, for example through the upstream of the web running direction second suction box initially apply a lower negative pressure while then in the area where the fibrous web and the conveyor belt are in contact with the roll shell, a larger one Negative pressure is generated and in the subsequent third suction box a lower negative pressure is applied again, to adverse influences on the fibrous web at extraordinary to avoid high web speeds. Such a use of further suction boxes before and after the central suction box associated with relatively little overhead, since practically to achieve the necessary rigidity of the external suction box anyway rigid cross-sections in the area of the inlet and outlet gussets are necessary.

Also can vacuum separately adjustable in the suction boxes, In particular, be controllable / controllable, so as to an optimal adjustment to allow for different operating conditions.

to Sealing the at least one suction box against the conveyor belt are expediently transverse to the web running direction extending sealing strips provided. This is especially in the area a gusset that was enclosed by one of the suction boxes is provided, a sealing strip. This will be an effective one Sealing of suction boxes ensures leakage to avoid.

It it is understood that the above and the following not yet to be explained features of the invention in the each specified combination, but also in other combinations and can be used alone, without the scope of the invention to leave.

The Suction device according to the invention is suitable in Excellent for use in a machine for manufacturing a fibrous web, in particular paper or board web, since in this case the Advantages of the suction device according to the invention fully come to fruition.

Further Features and advantages of the invention will become apparent from the following Description of preferred embodiments with reference on the drawing.

It demonstrate

1 a first embodiment of a suction device according to the invention in a sectional and highly simplified representation;

1A a sectional view of 1 according to the section line AA;

2 a second embodiment of a suction device according to the invention in a sectional and highly simplified representation;

2A a sectional view of 2 according to the section line BB;

3 a third embodiment of a suction device according to the invention in a sectional and highly simplified representation;

3A a sectional view of 3 according to the section line CC; and

4 shows an exemplary section of a honeycomb structure of the suction device of the invention 3 ,

The 1 to 3 show three exemplary embodiments of a suction device 1 for a fibrous web 2 producing machine in a cut and simplistic presentation. In the at least single-layer fibrous web 2 in particular, it can be a paper or board web, in the case of the machine, which is not completely illustrated, in particular a paper or board machine.

The respective suction device 1 comprises a suction roll D.3 having a suction roll 3 with a supporting and a roller tube diameter D.4 having roller tube 4 and with one around the supporting roller tube 4 arranged support structure 5 which is both air permeable and a conveyor belt 6 with fibrous web lying thereon and to be drained 2 in a wrap area 7 wearing. The wrap area 7 By definition, this is the range, ie the length between the casserole point 8th of the conveyor belt 6 on the support structure 5 and the expiry point 9 of the conveyor belt 6 from the support structure 5 , The fibrous web 2 has a web running direction L.2 (arrow).

The Ratio of roller tube diameter D.4 to suction roller diameter D.3 is ≥ 0.75, preferably ≥ 0.80, in particular ≥ 0.85. The roller tube diameter can have a value in the range of 500 to 2,000 mm, preferably from 800 to 1,800 mm.

Furthermore, the respective suction device comprises 1 an external suction box 10 that's the suction roller 3 partially encloses from the outside and the conveyor belt 6 and thus the fibrous web to be dewatered 2 with an external, of at least one on the suction box 10 connected vacuum source 11 generated negative pressure p _U applied. The preferably controllable / controllable vacuum source 11 is merely indicated by means of an arrow, since it is well known to the skilled person, both constructively and functionally.

Between the supporting roller tube 4 the suction roll 3 and the outer, the conveyor belt 6 carrying area 12 the support structure 5 the suction roll 3 is at least one annulus 13 available, so that about this with the external suction box 10 generated negative pressure p _U at the on the support structure 5 in the wrap area 7 overhead conveyor belt 6 and thus on the fibrous web to be drained 2 can work.

The annulus 13 the single suction roll 3 is also from at least one inner area 14 the support structure 5 educated. Also, the annulus is in the circumferential direction of the suction roll 3 without interruptions or possible interruptions of the annulus 13 in the circumferential direction of the suction roll 3 are spaced so far apart that the negative pressure effect on the conveyor belt 6 and thus on the fibrous web to be dewatered 2 in the entire wrapping area 7 not disturbed or even prevented.

The air permeable support structure 5 the respective suction roll 3 consists of a corrosion resistant material 15 , in particular a stainless steel, preferably an austenitic stainless steel or a ferritic-austenitic duplex steel. The austenitic stainless steel may comprise four main families: the molybdenum-free Cr-Ni steels, such as 1.4307, 1.4306 or 1.4301 according to DIN EN 10088/1 , the molybdenum-containing Cr-Ni-Mo steels such as 1.4401, 1.4404, 1.4432, 1.4435 or 1.4436 according to DIN EN 10088/1 , the high-alloyed special austenites and the manganese austenites.

On the other hand has the ferritic-austenitic duplex steel in cheaper Make a carbon content of at most 1.2 wt.%, Preferably of not more than 0.10% by weight, in particular of not more than 0.030% by weight, one Nitrogen content in the range of 0.05 to 0.40 wt.%, In particular from 0.05 to 0.22 wt.%, a chromium content in the range of 20.0 to 30.0% by weight, in particular from 21.0 to 24.0% by weight, of a nickel content in the range from 1.0 to 8.0% by weight, in particular from 1.5 to 6.5% by weight, and a molybdenum content in the range of 0.0 to 5.0 wt.%, in particular from 0.1 to 3.5% by weight.

Furthermore, the roller tube 4 the single suction roll 3 on its outer surface 16 with a protective medium 17 to protect them from direct contact with the corrosive process media. The protective medium 16 can for example As a paint, a (spray) coating or a plating with corrosion-resistant sheet metal include. Due to the provision of the protective medium 17 there is the roller tube 4 the single suction roll 3 made of a non-corrosion resistant material 18 , in particular a structural steel, such as a St-37 or St-52.

In the embodiment of the 1 is the outer area 14 the air permeable support structure 5 now at least one perforated hollow cylinder 19 , The perforated hollow cylinder 19 consists for example of a bent and assembled, in particular a welded sheet metal 20 , preferably a perforated plate, and has a wall thickness d.19 in the range of 0.5 to 8 mm, preferably from 1 to 6 mm, in particular from 2 to 5 mm. Also, the perforation of the thin-walled hollow cylinder 19 have an irregular or regular pattern, for example when forming pattern lines or areas.

Depending on the width of the suction roll 3 may be the outer region of the air-permeable support structure 5 also consist of several along the roller length L.3 (arrow) arranged adjacent hollow cylinder segments.

The 1A shows a sectional view of 1 according to the section line AA.

The respective suction device 1 comprises a suction roll D.3 having a suction roll 3 with a supporting and a roller tube diameter D.4 having roller tube 4 and with one around the supporting roller tube 4 arranged support structure 5 which is both air permeable and a conveyor belt 6 with fibrous web lying thereon and to be drained 2 in a wrap area 7 wearing. The wrap area 7 By definition, this is the range, ie the length between the casserole point 8th of the conveyor belt 6 on the support structure 5 and the expiry point 9 of the conveyor belt 6 from the support structure 5 ,

The additional device 21 in the present embodiment comprises a supporting and static yoke 22 which extends through the entire supporting roller tube 4 extends and, merely indicated, at its two ends 23 in the two-sided racks 24 the machine is stored statically. The carrying roller tube 4 is again over several hydrostatic elements 25 at the supporting and static yoke 22 supported, the hydrostatic elements 25 preferably adjustable, in particular controllable / regulated.

Such an additional device is for example from the German patent application DE 25 55 677 A1 The content of which is hereby made the subject of the present description.

The 2A shows a sectional view of 2 according to the section line BB.

In the embodiment of the 3 is the outer area 14 the air permeable support structure 5 from at least one of upstanding bands 27 composite honeycomb structure 26 containing a variety of honeycombs 28 having. The honeycomb structure 26 has an in or approximately in the circumferential direction of the suction roll 3 aligned longitudinal extent and the honeycomb 28 the honeycomb structure 26 are in the circumferential direction of the suction roll 3 offset from one another (cf. 4 ).

The honeycomb structure 26 has a height H.26 in the range of 3.0 to 25.0 mm, preferably from 4.0 to 20.0 mm, in particular from 5.0 to 15.0 mm.

In another, in the 3 merely indicated embodiment, the additional device 21 alternatively, a second rotating roller tube 29 which extends through the first supporting roller tube 4 extends and with the first supporting roller tube 4 only in the middle of the roll M.3 (arrow) is connected. The second rotating roller tube 29 is here at its two ends 23 , preferably via pins, again in the racks 24 rotatably mounted the machine.

Such an additional device 21 is for example from the German patent application DE 101 12 202 A1 The content of which is hereby made the subject of the present description.

The 3A shows a sectional view of 3 according to the section line CC.

The inner area 14 each in the 1 to 3 illustrated air permeable support structure 5 the suction device 1 is off in the longitudinal direction of the suction roll 3 spaced supports 30 , such as Hochkantringen (see. 1 and 1a ) or honeycomb 28 (see. 3 and 3a ), or spacers 31 , such as pins (cf. 2 and 2a ), all of which are part of the air permeable support structure 5 are. Here are the supports 30 or the spacers 31 at their inner ends 32 suitably with the supporting roller tube 4 connected. The connection can, for example, by shrinking the air-permeable support structure 5 on the supporting roller tube 4 take place, wherein the supporting roller tube 4 a roller tube diameter D. 4 has. The inner area 14 the respective air permeability gene support structure 5 has a height H.14 in the range of 5.0 to 50.0 mm, preferably from 10.0 to 40.0 mm, in particular from 15.0 to 30.0 mm. The support structure 5 is permeable to air and carries in an implied manner the conveyor belt 6 with fibrous web lying thereon and to be drained 2 in a non-illustrated wrap area.

Furthermore, in the two embodiments of the 2 and 3 two more suction boxes 33 . 34 provided to the first suction box 10 adjacent and the to be drained fibrous web 2 over the conveyor belt 6 apply negative pressure pU.

Here is the first suction box 10 as the central, the suction roll 3 Partially enclosing suction box 10 formed, extending from the inlet gusset 35 to the outlet gusset 36 extends. Furthermore, in the web running direction L.2 (arrow) seen in front of the suction roll 3 the second suction box 33 arranged, extending to the first suction box 10 extends and the against the conveyor belt 6 is sealed. And in the web direction L.2 (arrow) seen after the suction roll 3 is the third suction box 34 arranged, extending to the first suction box 10 extends and the against the conveyor belt 6 is sealed. The respective negative pressure p _U in the suction boxes 10 . 33 . 34 is separately adjustable, in particular controllable / controllable. Moreover, to seal the two suction boxes 33 . 34 against the conveyor belt 6 transverse to the web running direction L.2 (arrow) extending, the skilled person well-known sealing strips 37 intended.

The 4 shows an exemplary section of a honeycomb structure 26 the suction device 1 of the 3 , The honeycomb structure 26 is composed of a variety of upstanding bands 27 , from straight bands 38 . 39 which extend in the circumferential direction and between which there is a certain distance, and arranged between the straight bands zigzag bands 40 , At the points of contact 41 are the zigzag bands 40 with the straight bands 38 . 39 welded. The bands 38 . 39 . 40 thus form a variety of trapezoidal honeycomb 28 ,

In the present embodiment stand by a particular arrangement of recesses 42 in the tapes 38 . 39 now each some adjacent honeycomb with each other in line connection. And indeed have the straight bands 39 each between the points of contact 41 with the zigzag bands 40 cutouts 42 , These can be, for example, circular holes. The zigzag tapes 40 also have recesses 43 on, and according to a specific pattern, so that honeycomb groups are formed by specific shape. For example, there are six honeycombs each, for example the honeycomb 44 to 49 combined into a honeycomb group. Between adjacent honeycomb groups, for example 44 to 49 and 50 to 55 , there is no line connection. As you can easily see, the honeycomb groups extend 44 to 49 and 50 to 55 in diagonal direction.

One in the 4 illustrated honeycomb structure 26 is for example from the German patent application DE 32 10 320 A1 The content of which is hereby made the subject of the present description.

The respectively in the 1 to 3 illustrated suction device 1 is particularly suitable for use in a machine for producing a fibrous web, in particular a paper or board web.

In summary can be stated that improved by the invention Suction device with a suctioned from the outside of the roller initially mentioned type is created, the said disadvantages as far as possible, preferably completely avoided. Especially the roller tube can be made cheaper and it has a higher load capacity or it allows additional measures to increase the carrying capacity.

1

suction

2

Fibrous web

3

suction roll

4

roll tube

5

support structure

6

conveyor belt

7

wrap region

8th

accumulating point

9

the end point

10

suction box

11

Vacuum source (Arrow)

12

Outer Area

13

annulus

14

inner Area

15

material

16

surface

17

protective medium

18

material

19

hollow cylinder

20

sheet

21

Facility

22

yoke

23

The End

24

frame

25

hydrostatic element

26

honeycomb structure

27

tape

28

honeycomb

29

second roll tube

30

support

31

spacer

32

Interior The End

33

second suction box

34

third suction box

35

inlet pocket

36

outlet pocket

37

sealing strip

38

straight tape

39

straight tape

40

Zigzag tape

41

contact point

42

recess

43

recess

44 to 49

honeycomb (Honeycomb group)

50 to 55

honeycomb (Honeycomb group)

A-A

intersection

B-B

intersection

C-C

intersection

D.3

Saugwalzendurchmesser

D.4

Rolling tube diameter

d.19

wall thickness

H.14

height (inner area)

H.26

height (Honeycomb structure)

L.2

Web direction (Arrow)

L.3

length (Arrow)

L.4

length (Arrow)

M.3

roll center (Arrow)

p _U

vacuum

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• US 2270464 [0003]
• EP 0889165 B1 [0004, 0027]
• - DE 3210320 A1 [0019, 0068]
• DE 2555677 A1 [0025, 0056]
• - DE 10112202 A1 [0026, 0061]

Cited non-patent literature

• - DIN EN 10088/1 [0013]
• - DIN EN 10088/1 [0013]
• - DIN EN 10088/1 [0048]
• - DIN EN 10088/1 [0048]

Claims (27)

Suction device ( 1 ) for a fibrous web ( 2 ), in particular paper or board web, producing machine, in particular paper or board machine, comprising a suction roll diameter (D.3) having suction roll ( 3 ) with a carrying roller tube and a roller tube diameter (D.4) ( 4 ) and with a supporting roller tube ( 4 ) arranged support structure ( 5 ), which is both permeable to air and a conveyor belt ( 6 ) with fibrous web lying thereon and to be dewatered ( 2 ) in a wrapping area ( 7 ), and an external suction box ( 10 ), the suction roll ( 3 ) from the outside partially encloses and the conveyor belt ( 6 ) and thus the fibrous web to be dewatered ( 2 ) with an external, of at least one of the suction box ( 10 ) connected vacuum source ( 11 ) applied negative pressure (PU), wherein at least one annulus ( 13 ) between the supporting roller tube ( 4 ) of the suction roll ( 3 ) and the outer, the conveyor belt ( 6 ) carrying area ( 12 ) of the support structure ( 5 ) of the suction roll ( 3 ) is present, so that about this with the external suction box ( 10 ) generated at the on the support structure (pU) 5 ) in a wrapping area ( 7 ) lying conveyor belt ( 6 ) and thus at the fibrous web to be drained ( 2 ), characterized in that the ratio of roller tube diameter (D.4) to suction roller diameter (D.3) is ≥ 0.75, preferably 0.80, in particular ≥ 0.85. Suction device ( 1 ) according to claim 1, characterized in that the annulus ( 13 ) of the suction roll ( 3 ) from at least one inner region ( 14 ) of the support structure ( 5 ) is formed and that the annulus ( 13 ) in the circumferential direction of the suction roll ( 3 ) without interruptions or possible interruptions of the annulus ( 13 ) in the circumferential direction of the suction roll ( 3 ) are so far apart that the negative pressure effect on the conveyor belt ( 6 ) and thus on the fibrous web to be dewatered ( 2 ) in the entire wrapping area ( 7 ) is not disturbed or even prevented. Suction device ( 1 ) according to claim 1 or 2, characterized in that the air-permeable supporting structure ( 5 ) made of a corrosion-resistant material ( 15 ), in particular a stainless steel, preferably an austenitic stainless steel or a ferritic-austenitic duplex steel. Suction device ( 1 ) according to one of the preceding claims, characterized in that the roller tube ( 4 ) of the suction roll ( 3 ) on its outer surface ( 16 ) with a protective medium ( 17 ), such as a paint, a (spray) coating or a plating with corrosion-resistant metal sheet, in order to protect them from direct contact with the corrosive process media. Suction device ( 1 ) according to one of the preceding claims, characterized in that the roller tube ( 4 ) of the suction roll ( 3 ) of a non-corrosion resistant material ( 18 ), in particular a structural steel, such as a St 37 or St 52, consists. Suction device ( 1 ) according to one of the preceding claims, characterized in that the outer region ( 12 ) of the air-permeable support structure ( 5 ) of at least one perforated and preferably thin-walled hollow cylinder ( 19 ) consists. Suction device ( 1 ) according to claim 6, characterized in that the perforated hollow cylinder ( 19 ) of a bent and joined, in particular a welded sheet metal ( 20 ), preferably a perforated plate. Suction device ( 1 ) according to claim 6 or 7, characterized in that the perforated hollow cylinder ( 19 ) has a wall thickness (d.19) in the range from 0.5 to 8 mm, preferably from 1 to 6 mm, in particular from 2 to 5 mm. Suction device ( 1 ) according to claim 6, 7 or 8, characterized in that the outer region ( 12 ) of the air-permeable support structure ( 5 ) consists of several along the roll length (L.3) adjacently arranged hollow cylinder segments. Suction device ( 1 ) according to one of claims 1 to 5, characterized in that the outer region ( 12 ) of the air-permeable support structure ( 5 ) from at least one of upstanding bands ( 27 ) composite honeycomb structure ( 26 ), which is a plurality of honeycombs ( 28 ) having. Suction device ( 1 ) according to claim 10, characterized in that the honeycomb structure ( 26 ) in or approximately in the circumferential direction of the suction roll ( 3 ) has aligned longitudinal extent. Suction device ( 1 ) according to claim 10 or 11, characterized in that the honeycombs ( 28 ) of the honeycomb structure ( 26 ) in the circumferential direction of the suction roll ( 3 ) are offset from each other. Suction device ( 1 ) according to claim 10, 11 or 12, characterized in that the honeycomb structure ( 26 ) has a height (H.26) in the range from 3.0 to 25.0 mm, preferably from 4.0 to 20.0 mm, in particular from 5.0 to 15.0 mm. Suction device ( 1 ) according to one of the preceding claims, characterized in that the inner region ( 14 ) of the air-permeable support structure ( 5 ) from in the longitudinal direction of the suction roll ( 3 ) spaced supports ( 30 ), such as Hochkantringen or honeycomb, or spacers ( 31 ), such as pins, which are all part of the air-permeable support structure ( 5 ) are. Suction device ( 1 ) according to claim 14, characterized in that the supports ( 30 ) or the spacers ( 31 ) at their inner ends ( 32 ) in a suitable manner with the supporting roller tube ( 4 ) are connected. Suction device ( 1 ) according to claim 14 or 15, characterized in that the connection by shrinking the air-permeable support structure ( 5 ) on the supporting roller tube ( 4 ) he follows. Suction device ( 1 ) according to claim 14, 15 or 16, characterized in that the inner region ( 14 ) of the air-permeable support structure ( 5 ) has a height (H.14) in the range from 5.0 to 50.0 mm, preferably from 10.0 to 40.0 mm, in particular from 15.0 to 30.0 mm. Suction device ( 1 ) according to one of the preceding claims, characterized in that the suction roll ( 3 ) at least one additional facility ( 21 ) for supporting the supporting roller tube ( 4 ) over its length (L.4), thereby increasing its load capacity and minimizing any deformations. Suction device ( 1 ) according to claim 18, characterized in that the additional device ( 21 ) a supporting and static yoke ( 22 ), which extends through the entire supporting roller tube ( 4 ) and at its two ends ( 23 ) in the racks ( 24 ) of the machine is stored statically. Suction device ( 1 ) according to claim 19, characterized in that the supporting roller tube ( 4 ) over several hydrostatic elements ( 25 ) on the supporting and static yoke ( 22 ), wherein the hydrostatic elements ( 25 ) are preferably adjustable, in particular controllable / regulated. Suction device ( 1 ) according to claim 18, characterized in that the additional device ( 21 ) a second rotating roller tube ( 4 ), which extends through the first supporting roller tube ( 4 ) and with the first supporting roller tube ( 4 ) is only connected in the center of the roll (M.4). Suction device ( 1 ) according to claim 21, characterized in that the second rotating roller tube ( 4 ) at both ends ( 23 ), preferably via pins, in the racks ( 24 ) of the machine is mounted rotating. Suction device ( 1 ) according to one of the preceding claims, characterized in that at least one further suction box ( 33 . 34 ) provided to the first suction box ( 10 ) adjacent and the dewatered fibrous web ( 2 ) over the conveyor belt ( 6 ) with negative pressure (p _U ) acted upon. Suction device ( 1 ) according to claim 23, characterized in that the first suction box ( 10 ) as the central, the suction roll ( 3 ) from the outside partially enclosing suction box ( 10 ) is formed, which extends from the inlet gusset ( 35 ) to the outlet gusset ( 36 ), that in the web running direction (L.2) seen in front of the suction roll ( 3 ) a second suction box ( 3 ), which extends to the first suction box ( 10 ) and which against the conveyor belt ( 6 ) is sealed, and that in the web running direction (L.2) seen after the suction roll ( 3 ) a third suction box ( 34 ), which extends to the first suction box ( 10 ) and which against the conveyor belt ( 6 ) is sealed. Suction device ( 1 ) according to claim 23 or 24, characterized in that the negative pressure (p _U ) in the suction boxes ( 10 . 33 . 34 ) is separately adjustable, in particular controllable / regulated. Suction device ( 1 ) according to one of the preceding claims, characterized in that for sealing the at least one suction box ( 33 . 34 ) against the conveyor belt ( 6 ) transverse to the web running direction (L.2) extending sealing strips ( 37 ) are provided. Machine for producing a fibrous web ( 2 ), in particular paper or board web, characterized in that it comprises at least one suction device ( 1 ) according to one of the preceding claims.