Patent Application
20080305937
1. Technical Field
The invention relates to a thermally treatable roller body for treating a web-shaped material, for example for manufacturing paper.
2. Description of the Related Art
Thermally treatable roller bodies with axial bores for a thermal treatment fluid are known for example from U.S. Pat. No. 7,097,605. Instead of drilling the channels for the thermal treatment fluid into a shell of the roller body, the channels can also be formed by means of profiles which are fastened to an inner circumferential area of the shell. Such profile channels are for example described in U.S. Pat. No. 2,932,091. The advantage is that it is possible to fall back on prefabricated profiles in order to provide the channels and that material can be saved on the shell. The shell can also be formed from a material which need not be suitable for introducing the bores, which are generally several metres long. Semicircular profiles or L profiles which are bevelled outwards at their ends in the manner of a bracket are used in accordance with U.S. Pat. No. 2,932,091. The semicircular profiles are welded onto the shell by means of fillet welds by supplying an additive. The L profiles are placed onto each other in such a way that they each abut the shell with one end and the edges of an immediately adjacent L profile with their respectively other end, where they are welded. In this way, the L profiles form rectangular channels, the side walls of which are formed by two immediately adjacent L profiles. The embodiment with the semicircular profiles is problematic with regard to accessibility for the welding tool, while the rectangular channels each comprise three welded seams and the L profiles each have to abut the edge of an adjacent profile via one of their limbs.
It is an object of the invention to simplify the manufacture of roller bodies with profile channels.
The subject of the invention is a roller body for treating a web-shaped material, which comprises a shell and axially extending profiles which are arranged on the inside of the shell, i.e. on an inner circumferential area of the shell, are distributed about a rotational axis of the roller body and together with the shell form channels for a thermal treatment fluid which are axial or extend at least substantially axially. The channels preferably extend continuously from one axial end to the other axial end of the shell. Before being joined, the profiles are open in cross-section on one longitudinal side, where they are connected to the shell in a seal over their axial length, such that for each of the channels, the shell forms the outer wall and one of the profiles respectively forms all the other walls, in particular the side walls of the respective channel. The profiles abut the shell along their two side walls, which limit the open longitudinal side of the respective profile to the left and right, and are fixedly connected, fluid-proof, to the shell along the side walls by means of a connecting seam which is produced by soldering or preferably welding. The connecting seams can also be adhesive seams, if the roller body is operated at a correspondingly low temperature which adhesive seams withstand. In such embodiments, the roller bodies can also consist of plastic, preferably fibre-reinforced plastic, and the channels can be adhered or laminated onto the roller body.
In accordance with the invention, the side walls of immediately adjacent profiles exhibit an inclination of less than 90° to the shell, more specifically to the inner circumferential area of the shell, up to the respective connecting seam. As viewed in the cross-section of the roller body, a space is obtained between the side walls of immediately adjacent profiles which is limited in the circumferential direction to the left and right of the two side walls of the immediately adjacent profiles up to the connecting seam and tapers up to the connecting seam. This improves accessibility to the connecting seam, in particular for a joining tool and for checking purposes. As compared to profiles which are for example semicircular in cross-section, in which the side walls of the channels correspondingly meet the shell at a right angle, the distances between immediately adjacent channels as measured in the circumferential direction about the rotational axis can be reduced. The intermediate space obtained between the inclined side walls up to the connecting seam enables the profiles to be arranged more closely in the circumferential direction.
The side walls formed by the profiles are preferably linear, i.e. they run relative to the inner area of the roller shell at a constant inclination, which is greater than 0° and smaller than 90°, up to the respective connecting seam. Alternatively, however, they can also be curved in cross-section, i.e. they can extend at an inclination which changes in the direction of the inner shell area, up to the connecting seam. Linear side walls are however advantageous, on the one hand with respect to avoiding dead spaces in the flow cross-section and on the other hand with respect to as good an accessibility for the joining tool as possible. The side walls limit the profiles to the left and right on the lower side which is open towards the shell.
In preferred embodiments, the profiles are angled profiles. V profiles are particular suitable. It is advantageous if the two limbs of the V profile together enclose an angle in the range of 60 to 120°. The limbs of the V profiles are preferably of equal length. V profiles are cost-effective and, with regard to their geometry, a particularly good compromise between the flow-engineering conditions in the channels, the requirements of the joining process and commercial procurability. L profiles, i.e. V profiles in which the limbs forming the side walls point at right angles to each other, are particularly suitable. Instead of the preferred simple V profiles, however, it is also for example possible to use profiles having a trapezoidal cross-section, i.e. boat-shaped profiles with side walls which preferably point to each other in a V shape, or otherwise polygonal profiles.
The invention understands side walls to mean only those profile walls which limit a flow cross-section of the fluid, i.e. which are in contact with the fluid flowing through on their inner side when the roller is in operation. It is these side walls which protrude up to the respective connecting seam. On each of the side walls connected to the shell, the connecting seam therefore extends directly along the rim edge or rim area of the side wall which faces the shell and not slightly away from the side wall. This achieves a particularly true-to-shape connection between the side walls and the shell. In the region of their rim which faces the inner area of the shell, the side walls can no longer rise off the inner shell area due to mechanically or thermally induced stresses. The danger of them rising off exists if the profiles comprise connecting flanges which bend away from the side walls, and are connected to the roller shell slightly away from the side walls in the region of the connecting flanges.
The inclination of the side walls is preferably selected from the range of 30° to 60°, such that the side walls, or a tangent onto the respective side wall, and the inner circumferential area of the shell enclose an angle in the cited range, at the point of their connecting seam. The side walls of immediately adjacent profiles are correspondingly spread away from each other, from their connecting seam outwards, at an angle in the range of 60° to 120°. A spreading angle in the range around 90°, corresponding to an inclination of the side walls of about 45° with respect to the inner circumferential area of the shell, is ideal.
The side walls formed by the profiles can in principle be connected to the shell by means of a fillet weld; however, the connecting seams are more preferably V seams. Since, in preferred embodiments, the shell exhibits a simple, smooth area on its inner circumferential area in the region of the respective connecting seam, the connecting seam is technically only a half V seam. Using angled profiles, in particular simple V profiles with only two limbs, is particularly suitable for forming such connecting seams. If the angled profile is for example formed by bevelling a metal sheet, the facing areas at the two free ends of such a profile already inherently point at an inclination to the inner circumferential area of the shell when the ends of the limbs are positioned onto the inner circumferential area of the shell. Round profiles which are formed by bending round metal sheets and extend in cross-section over an angle in the range of for example 90° to 120°, can however likewise be used with respect to the preferred seam form as a V seam. Although profiles are preferably used which already inherently comprise a facing area at each of their two free ends which points at an inclination to the inner circumferential area of the shell when positioned, the profiles can however also be provided with a corresponding phase at their two free facing areas by machine-finishing, for example grinding, in order to produce V seams. In preferred embodiments, the angle which the facing areas of the side walls and the inner circumferential area of the shell enclose is selected from the range of 30° to 60°.
In preferred embodiments, the profiles and the roller shell are welded to each other without additives. One preferred welding method is electron-beam welding. In the case of energy-beam welding, the profiles and the roller shell are advantageously made of homogeneous materials, which is favourable for welding without additives. In principle, however, the profiles can also be welded with additives; for instance, the connecting seams can be welded using powder. Electron-beam welding is also a particularly preferred welding method when using additives, wherein homogeneous materials are also advantageously employed in this case, i.e. the profiles and also the additive welding material are each homogeneous with the material of the roller shell. Gas shielded welding is likewise a candidate for welding, as is laser welding as another method of energy-beam welding. The additive can be supplied in the form of a welding or soldering wire, as applicable also in addition to a powdered additive material. If the demands on thermal and mechanical stability permit, they can also be soldered or as applicable bonded, for example adhered or laminated on. The connecting seams can be machine-finished, for example by grinding, in order to avoid notching effects at the transition from the connecting seam to the profile or as applicable to the shell.
The profiles can be adjacently arranged in the circumferential direction, sufficiently closely that immediately adjacent profiles are connected to the shell by means of the same connecting seam. In particular when welding by means of an energy beam, the profiles can be arranged with the respectively adjacent side walls tightly packed on the inner circumferential area and/or inner area of the shell or—as discussed again below—an annular shell part which is then joined to the shell together with at least one other annular shell part. In particular in energy-beam welding, a plurality of connecting seams can be simultaneously produced adjacently in one welding operation, either by means of different energy-beam welding tools or preferably one energy-beam welding tool with a fan of partial beams. Particularly preferably three, four or five connecting seams, or as applicable only two or also six connecting seams, are adjacently produced simultaneously by moving the welding tool with the plurality of partial beams or a plurality of welding tools forwards along the profiles in the welding direction in one processing operation and so producing the connecting seams. For welding with additives in particular, but also when welding without additives, the profiles for joining can also be arranged such that a narrow gap respectively remains between profiles which are immediately adjacent in the circumferential direction, into which additive can be supplied and melted, in order to produce the respective connecting seam.
For joining the profiles, it is advantageous if the shell is composed of a plurality of annular shell parts. The annular shell parts are joined to the shell. The annular shell parts extend in the circumferential direction about a rotational axis of the shell, preferably each over an angle of at most 180°. Even more preferably, they each only extend over an angle of at most 120°. An angle of 120° is particularly preferred. In such embodiments, the roller shell or merely an axial segment of the shell consisting of three annular shell parts is joined. The annular shell parts can in particular be identical to each other in terms of size and shape. On the other hand, the possibility is not to be excluded that they differ from each other with respect to their axial length or circumferential extension. The annular shell parts are preferably cylindrical on their outer circumferential area or their inner circumferential area; particularly preferably, they are cylindrical on both circumferential areas. Constructing the roller shell from annular shell parts of the type cited is advantageous for joining the profiles, since the joining tool can be deployed from the open side of the respective annular shell part and guided along the profiles in order to produce the connecting seam or to preferably simultaneously produce the plurality of seams. Accessibility is significantly improved as compared to welding in a closed shell.
After joining the profiles with the annular shell parts, wherein the profiles preferably each only extend over the axial length of a single annular shell part, the annular shell parts are joined to the roller shell. The statements made with respect to joining the profiles apply similarly to joining the annular shell parts. The annular shell parts are likewise preferably joined by energy-beam welding, particularly preferably by electron-beam welding. The annular shell parts can in particular be joined by means of I connecting seams along their facing areas which face each other during joining. The connecting seams can in principle point at an inclination to the rotational axis of the roller shell to be produced, but preferably extend parallel to the rotational axis. The roller shell can be joined from a plurality of shell segments in the axial direction, wherein the circumferential connecting seam or the plurality of circumferential connecting seams of the shell segments are likewise preferably I seams.
Manufacturing the shell from annular shell parts is preferably used in combination with the flow channels formed in accordance with the invention; however, joining from annular shell parts is also advantageous in its own right, in particular in combination with profiles which are arranged and joined for forming flow channels on the inner area of the annular shell parts, before the annular shell parts are joined to each other to form the roller shell. The shell is preferably formed from sheet steel. The profiles are preferably likewise steel sheets.
The shell can be over 8 m, even over 10 m long and can have an outer diameter of over 100 cm, even over 120 cm. It is a few centimetres thick. The profiles can be the same length as the shell, as applicable even slightly longer; preferably, they are a few centimetres shorter than the shell. If the shell is composed of annular shell parts, then this applies, with regard to profiles which may protrude, to the outer annular shell parts axially to the left and right, and correspondingly to the axial portions of the profiles arranged there. As measured onto the inner circumferential area of the shell, the profiles have a height in the centimetre range, preferably between 1 and 8 cm. V profiles advantageously have a limb length of 1 to 10 cm. The thickness of the profiles, in particular the side walls, is a few millimetres, preferably 2 to 8 mm.
Fittings can be arranged in the channels, in order for example to constrict the flow cross-section and so affect the transfer of heat to the shell. The fittings can also merely serve to produce turbulence, i.e. can be optimised in their geometry with respect to their turbulence-producing effect. The fittings can advantageously be arranged and, if necessary, fastened in the profiles before the profiles are joined to the shell.
Forming the channels by means of profiles also enables the flow cross-section of each channel or of selected channels in the axial profile of the respective channel to be varied in a simple way. One simple and therefore preferred variation is to vary the height of the channels or only of the selected channels as measured radially with respect to the rotational axis of the roller body. The side walls formed by the two limbs of for example a V profile, or also the side walls of any other profile cross-section, can thus be shortened as viewed over the axial length of the respective profile. Thus, the flow cross-section can be reduced in the flow direction of the thermal treatment fluid, in order to equalise the transfer of heat onto the shell due to the associated increase in the flow velocity when there is a decrease in the difference in temperature between the thermal treatment fluid and the shell over the axial length of the respective channel.
If outward and return flow channels are formed by the profiles, in order for example to supply the thermal treatment fluid at one axial end of the shell and drain it off again at the same end, a plurality of groups of profiles can be used, wherein the profiles within each group exhibit the same cross-section and the profiles from group to group exhibit different cross-sections. Thus, the profiles of one group can exhibit a large cross-section, i.e. a large cross-sectional area, and the profiles of the other group or of one or more other groups can exhibit a smaller cross-section, in order to form outward flow channels and return flow channels which differ from each other in the cross-section of the profiles. In particular, the outward flow channels can be formed by the profiles having the larger cross-section, and the return flow channels can be formed by the profiles having the smaller cross-section. Advantageously, at least one of the profiles having the smaller cross-section is arranged between the profiles having the larger cross-section. If, as is preferred, the profiles having the smaller cross-section are radially flatter, with respect to the rotational axis, than the profiles having the larger cross-section, then accessibility to the ends of the profiles which are to be joined is also improved in such an arrangement. Simple V profiles or L profiles are also advantageous for such embodiments, wherein it is also preferred if the limbs of these angled profiles enclose the same angle—for example, each point at right angles to each other—in each of the two or even more groups of profiles. Merely for the sake of completeness, it may be noted that the profiles of the outward flow channels and the profiles of the return flow channels can also be identical.
The thermal treatment fluid is preferably distributed via a distributor space into the channels or—in the case of outward flow channels and return flow channels—into the outward flow channels, or is collected in a collecting space after it has flowed through the channels or—in the case of outward flow channels and return flow channels—the outward flow channels. Here, as elsewhere, the word “or” is understood in the sense of “and/or”, i.e. it includes in each case the meaning of “either . . . or” and also the meaning of “both . . . and”. Accordingly, either a distributor space only or a collecting space only or, as is preferred, both a distributor space and a collecting space or a plurality of distributor spaces or a plurality of collecting spaces can be provided. The distributor space or collecting space is formed at an axial end of the shell, for example in a trunnion flange arranged at the axial end or preferably in the shell. If the thermal treatment fluid only flows through the roller body in one axial direction, then a distributor space is formed at the inflow end and a collecting space is formed at the outflow end in preferred embodiments. The distributor space or collecting space is understood to mean a space which extends up to the periphery in the radial direction or is formed there as an annular space, in order to connect all the channels or—in the case of outward flow channels and return flow channels—only the outward flow channels or only the return flow channels or as applicable also only a subgroup of the respective channels fluidically to each other.
If the thermal treatment fluid is supplied and drained off at the same axial end, a distributor space and a collecting space are formed at said supplying and draining end in preferred embodiments. A collecting space is preferably formed at the opposite end in such embodiments. A distributor space can also be formed there. If a distributor space or collecting space is formed or a plurality of distributor spaces or collecting spaces are formed, one or more of these spaces—preferably, all of these spaces—can be arranged in the shell. Alternatively, however, one or more of these spaces or all of these spaces can also be formed in one of the trunnion flanges or in both trunnion flanges. Mixed forms are also conceivable, in which a distributor space or collecting space is formed in the shell and a collecting space or distributor space is formed in one of the trunnion flanges.
A distributor space or collecting space can advantageously be formed by a disc-shaped or flatly curved partition structure—in the preferred simplest case, an at least substantially planar partition disc. Along its outer circumference, the partition structure comprises cavities for the channels or merely for a part of the channels. The relevant channels protrude through the partition structure in the region of the cavities or protrude into the cavities or up to the cavities. The cavities are shaped to conform to the outer contour of the channels protruding through them and are connected, for example soldered or preferably welded, to said channels, fluid-proof. If V profiles or L profiles are used, the partition structure comprises a correspondingly serrated profile over its outer circumferential rim.
In alternative embodiments, connecting channels are formed in a single trunnion flange or in a left-hand and a right-hand trunnion flange, for example as radially extending bores which connect a central supply line or drainage line to a distributor space or collecting space and to the channels or some of the channels.
In addition to the flow guides already cited, on the one hand only comprising outward flow channels, i.e. with a fluid supply at one axial end of the roller and a fluid drain at the other axial end of the roller, and a simple outward and return flow with a supply line and a drainage line at the same end, other flow guides can also be realised, for example a triple through-flow, namely a supply line at one end of the roller, an outward flow, a return flow, another outward flow and a drainage line at the other end of the roller. A quadruple through-flow of the roller body can also be realised, comprising—one after the other in the flow direction—a first outward flow channel, a first return flow channel, a second outward flow channel and a second return flow channel, i.e. with a supply line and a drainage line for the thermal treatment fluid at the same end of the roller. An equally advantageous variant is the supply line at one end of the roller and distribution into outward flow channels, wherein two adjacent outward flow channels are combined to form a return flow channel at the other end of the roller, i.e. the fluid flowing in the two outward flow channels to the other end flows back completely or at least partially from the two outward flow channels in a return flow channel and is drained off again at the same end of the roller.
In addition to the roller body itself, the invention also relates to a roller which comprises the roller body and is fitted in a web-treating machine, for example a paper machine, or is provided for being fitted. At each of the axial ends of the roller shell, the roller comprises a trunnion flange for rotationally mounting and distributing fluid or at least for sealing and preferably also for rotary-driving. One or both trunnion flanges can in particular close off a distributor space or collecting space formed at the respective axial end.
Example embodiments of the invention are illustrated below on the basis of figures. The features disclosed by the example embodiments, each individually and in any combination of features, advantageously develop the subjects of the claims and also the configurations illustrated above. There is shown:
A distributor system for the thermal treatment fluid is formed in the interior of the shell 1. A central supply line 4 and, concentrically around the supply line 4, a drainage line 5 for the thermal treatment fluid extend in the axial direction through the trunnion flange 3. The drainage line 5 is obtained, by means of a pipe inserted into the trunnion flange 3, as an annular gap between the pipe and a surrounding inner shell area of the trunnion flange 3. Alternatively, the drainage line 5 could also be obtained by bores which extend axially through the trunnion flange 3. In another modification, the drainage line 5 could be formed centrally and the supply line 4 could be formed to surround the drainage line 5. The thermal treatment fluid can be supplied to the distributor system through the supply line 4 and can be drained off through the drainage line 5. The distributor system includes, both on the supplying and draining side of the roller comprising the trunnion flange 3 and on the drive side comprising the trunnion flange 2, each of a distributor space 6 and a collecting space 7 as well as peripheral thermal treatment channels 10a and 10b which extend axially over the entire length of the shell 1, at any rate over the entire length over which the roller acts on a maximum-width web to be treated. The thermal treatment channels 10a and 10b are formed on the inner circumferential area of the shell 1, uniformly distributed about the rotational axis R. The thermal treatment channels 10a are outward flow channels, and the thermal treatment channels 10b are return flow channels. The thermal treatment channels 10a and 10b are adjacently arranged, alternately consecutive in the circumferential direction, i.e. each outward flow channel 10a is followed in the circumferential direction by a return flow channel 10b, and each return flow channel 10b is followed in the circumferential direction by an outward flow channel 10a.
The two distributor spaces 6 and the two collecting spaces 7 are axially limited by partition structures 8 and 9 and one of the trunnion flanges 2 and 3, respectively, and on the supplying and draining side are also fluidically separated from each other by the partition structure 9 on that side. The partition structures 8 and 9 are shaped as circular discs, each with a serrated outer circumferential rim. The partition structures 8 and 9 are arranged at the respective axial end of the shell 1 at a slight axial distance from each other and likewise at a slight axial distance from the respective trunnion flange 2 or 3, such that the distributor spaces 6 and collecting spaces 7 are each shaped as cylindrical discs. On the supplying and draining side, the distributor space 6 is limited between the partition structures 8 and 9, and the collecting space 7 is limited by the trunnion flange 3 and the partition structure 9. On the opposite drive side, the collecting space 7 is axially limited between the partition structures 8 and 9, and the distributor space 6 is limited by the partition structure 9 and the trunnion flange 2.
When the roller is in operation, the thermal treatment fluid is introduced centrally into the distributor space 6 of the supplying and draining side through the supply line 4 and flows on the circumferential rim of the axially inner partition structure 8, into the outward flow channels 10a. The thermal treatment fluid flows through the outward flow channels 10a in the axial direction and, via the outer circumferential rim of the axially opposite inner partition structure 8, enters the collecting space 7 there, where it is redirected inwards towards the rotational axis R and flows through a central opening of the axially outer partition structure 9, into the distributor space 6. The thermal treatment fluid flows radially outwards through the distributor space 6 of the drive side and, via the outer circumferential rim of the partition structure 9, enters the return flow channels 10b. The thermal treatment fluid flows through the return flow channels 10b in the axial direction, is collected in the collecting space 7 on the supplying and draining side, and flows back through the collecting space 7 and the central drainage line 5 into the external fluid supply system of the roller.
The profiles P are angled profiles—in the example embodiment, isosceles L profiles with a first limb 11 and a second limb 12 which together enclose an angle a of at least substantially 90°. The profiles P lie adjacently, closely spaced, such that profiles P which are immediately adjacent in the circumferential direction are connected to the shell 1 by means of a common, axially continuous welded seam 13. The welded seams 13 are welded using powder or even more preferably by means of an electron beam.
In particularly preferred embodiments, the profiles P and Pa and Pb can also be welded to the shell 1, and preferably also to each other in pairs, by means of energy-beam welding, in particular electron-beam welding, by being closely arranged adjacently in the circumferential direction, wherein they can also contact each other laterally. For joining without additives, homogeneous materials are advantageously welded to each other. For energy-beam welding, the profiles P or Pa and Pb can be arranged in a linear contact with the inner area of the shell 1, each with an inner edge on the facing side of the side walls 11 and 12, as shown in
The cross-sectional shape of the partition structures 8 and 9 can also be seen from the cross-sectional representation of
It may also be noted with respect to the distributor spaces 6 and collecting spaces 7 that they are still formed within the shell 1 in the example embodiment. In one modification, at least one—or both—axially outer spaces 6 and/or 7 could be formed in the respective trunnion flange 2 or 3. In another modification, both spaces 6 and 7 can be formed in the respective trunnion flange 2 or 3 at one axial end or at both axial ends.
Although the distributor and collecting system is preferably formed either with partition discs only or with distributor and collecting spaces formed in the trunnion flanges or as a welded distributor and collecting system only, mixed forms of the different distributor and collecting systems are not to be excluded, for example forming a distributor or collecting space at one end of the roller by means of one or more partition discs and forming a distributor space or collecting space at the other end of the roller in the trunnion flange at that end. It is thus, for example, possible to form the end of the roller of the supplying and draining side in accordance with the example embodiment of
Constructing the roller shell from annular shell parts 1a, 1b and 1c facilitates arranging and joining the profiles P—alternatively, the profiles Pa and Pb—on the inner shell areas of the annular shell parts 1a, 1b and 1c. The annular shell parts 1a, 1b and 1c comprise cylindrical inner and outer circumferential areas.
For joining, the profiles P are arranged on the inner area of the respective annular shell part 1a or 1b or 1c and joined to the annular shell part 1a, 1b or 1c by electron-beam welding. The profiles P—alternatively, the profiles Pa and Pb or profiles of another type—are preferably adjacently arranged sufficiently closely in the circumferential direction that the immediately adjacent side walls are welded to the respective annular shell part 1a, 1b or 1c by the same energy beam. In order to accelerate the welding process, a plurality of energy beams can be simultaneously moved forwards axially along the profiles P in the welding direction, wherein one of the connecting seams is continuously produced for each energy beam. Particularly preferably, four connecting seams which are consecutive in the circumferential direction are produced. If, as is preferred, they are arranged closely adjacent, then they are the connecting seams 13; if the profiles P or Pa and Pb are arranged at a distance, then they are the connecting seams 14 (
After joining the profiles P, Pa and Pb or profiles of another type, the annular shell parts 1a, 1b and 1c are fixed in a joining position relative to each other, either in pairs or all three simultaneously, and the connecting seams 1d are produced. As mentioned, the connecting seams 1d are likewise preferably produced by means of electron-beam welding. The profiles are preferably arranged such that when the connecting seams 1d are produced, one of the connecting seams for the profiles is also simultaneously produced. It is then in particular possible, as shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 102007026386.6 | Jun 2007 | DE | national |
