EP3196356B1 - Drying roller - Google Patents

Description

The invention relates to drying rollers, which consist at least of a cylindrical cylinder jacket, two attached on both sides of the cylinder jacket covers and two indirectly via a hollow shaft connected to the lids or directly attached to the lids pin, wherein the cylinder jacket and the lid by an annular weld with each other are welded.

From the DE 27 07 923 A1 For example, a drying or drying cylinder for drying webs of pulp or paper is known which comprises a jacket and covers arranged at the ends of the jacket. To avoid bending stresses during welding of the shell and the lid adjoins the sheat seam on the side facing away from the jacket edge on a transition piece, seen in an axial section through the cylinder in the seam region has approximately the strength of the shell, wherein the transition piece and the sheath in Seam area have a steady course.

In addition, for example, the shows WO 2008 / 105005A1 a steel-made drying roll of similar construction in which lids are welded to the ends of a cylinder jacket by means of a circumferential weld formed between opposed surfaces of each of the lids and the cylinder jacket. The weld consists of a recess of U-shaped cross-section open towards the outer surface of the cylinder jacket, which is formed by respective recesses between a respective end of the cylinder jacket and one of the lids and filled by welding material, on the inner surface of the cylinder jacket at the level of the recess a counter-bead is provided.

In such known drying rollers, the quality of the weld between cylinder jacket and lid can be difficult to verify. In particular, the examination of the weld quality in bottom regions of the welds remains problematic and is usually measurable only with radiographic methods.

It is therefore the object of the present invention to provide dry rolls with reliable welds and methods of making such dry rolls.

This object is achieved by the drying roller with the features of claim 1, wherein the dependent claims relate to preferred embodiments.

In this case, the invention is based on the common inventive basic idea to ensure the quality of the weld between the cylinder jacket and cover by a suitable design of the cylinder jacket and the lid in the vicinity of the weld.

Thus, a drying roller at least consist of a cylindrical cylinder jacket, two attached on both sides of the cylinder jacket covers and two indirectly via a hollow shaft connected to the lids or directly attached to the lids pin, wherein the cylinder jacket and the lid are welded together by an annular weld , and wherein the weld seam has a joint with at least two mutually opposite and spaced parallel flank regions.

In such a drying roll, because the weld has a joint with at least two parallel and oppositely disposed parallel flank regions, or in other words a joint with a land and a land pitch, beads forming a root pass of the weld can reliably also be from the outside be welded. In this way, the quality of the weld formed can be improved and their overall reliability can be increased. Thus, it is thereby possible to provide dry rollers with reliable welds and to provide methods for their production.

Such a drying roller can be set up for various uses during papermaking or for drying various types of paper. For example, the drying roller may in particular be a so-called Yankee roller, which is provided for drying so-called tissue papers or tissue papers or soft papers. But also so-called MG-rolls ( machine glazed ) for the production of machine-smooth papers are executable with such drying rollers. Furthermore, the drying roller can be used in the production of cardboard papers or graphic papers. Typically, Yankee rolls and MG rolls have two spigots attached indirectly via a hollow shaft connected to the covers, while dry rolls for producing cardboard papers or graphic papers often have spigots directly attached to the covers.

During drying, the material to be dried, such as paper or paperboard, usually has direct contact with the outer surface of the cylinder jacket, which may at least partially have a smooth surface on the inner side or at least in sections may be provided with one or more grooves may also be provided in bead-like thickening to counteract stresses that may act on the drying roller of outer pressure rollers or cylinders. The cover of the drying roller may be disc-shaped. For example, at least one of the lids may be a flat disk. However, at least one of the lids may also have a curved shape, for example similar to a dished bottom or basket bottom, or be formed with a semi-elliptical cross section. The hollow shaft may be provided for mounting the drying roller, wherein it reduces a force acting on the cylinder jacket or the cover voltage. Usually, the hollow shaft is of cylindrical shape with flat or conical end portions. It may be integral or multi-piece with two or more interconnected, for example, welded, soldered, bolted, locked or formed by bolt segments formed. In some embodiments, the hollow shaft is formed integrally with the pins. Furthermore, the pins are usually used in corresponding bearings or bearing housings, which support the entire arrangement of the drying roller and allow a rotational movement of the drying roller. In this case, components of the drying roller of different materials and in particular of metals such as steel, stainless steel, carbon steel, cast steel or cast iron can be made.

In one embodiment of a drying roller, the weld is welded without counter-bead, whereby the process reliability in the production of the weld improves because the weld is made particularly simple.

Furthermore, a drying roller may consist of at least one cylindrical cylinder jacket, two lids attached on both sides of the cylinder jacket, and two indirectly via a hollow shaft connected to the lids or pins secured directly to the lids, wherein the cylinder jacket and the lids are welded together by an annular weld , wherein the radially inner workpiece surfaces of both the lid and the cylinder jacket are cylindrical on both sides of the weld and wherein in at least one cover a closable or closed inspection opening is provided.

In such an embodiment of a drying roller, the inspection opening may be identical to a hole for the hollow shaft or the pins. Alternatively, a further opening for the hollow shaft or the pins may be provided in addition to the inspection opening. Depending on the size of the drying roller, the inspection opening can be designed as a manhole.

Furthermore, the drying roller can consist of at least one cylindrical cylinder jacket, two lids attached to both sides of the cylinder jacket, and two indirectly via a hollow shaft connected to the lids or pins secured directly to the lids, wherein the cylinder jacket and the lids are welded together by an annular weld , wherein the radially inner workpiece surface of the cylinder jacket between a condenser and the weld seam is cylindrical.

Also such a trained, so with cylindrical-shaped, radially inner surface of the workpiece both the cover and the cylinder jacket on both sides of the weld provided or provided with a cylindrical, radially inner surface of the cylinder jacket between a condenser and the weld, provided with a cylindrical, characterized by a good accessibility to the weld even from the inside, whereby the possibilities for checking the weld seam are improved with different test methods, whereby the quality of the weld can be ensured. In particular, the weld of such a trained drying roller can be tested by means of X-rays, ultrasound, penetration tests in the form of dye penetration and / or, but not limited thereto, by magnetic particles.

Advantageously, the capacitor has one, preferably a plurality, circumferential grooves. The larger the number of grooves, the better the effect of the capacitor.

Preferably, a machined transition radius and / or a transitional groove, preferably with at least one machined transition radius between groove flank of the transition groove and groove base of the transition groove, is provided between the cylindrical inner workpiece surface of the cylinder jacket and the condenser. This results in a good inspection option, a particularly high stability of the drying roller. The transition radius and / or the transition groove can be made in particular by means of milling or turning.

In a method for producing a drying roller at least consisting of a cylindrical cylinder jacket, of two attached on both sides of the cylinder jacket lids and two indirectly via a hollow shaft connected to the lids or directly secured to the lids pin, wherein the cylinder jacket and the lid are welded together by an annular weld, a distance between the respective lid to be welded and the cylinder jacket via at least one spacer can be defined before welding the lid with the cylinder jacket to this Way to provide a reliable weld.

In particular, this method makes it possible to produce a drying roller with a circumferential weld seam between the cylinder jacket and the cover, which has a joint with at least two parallel flank regions lying opposite one another and being spaced apart from one another.

Preferably, the lid to be welded in each case and the cylinder jacket are first tacked to one another via a tack weld and subsequently welded to one another only via weld beads. In this case, the tack weld allows pre-fixing of the cover to the cylinder jacket, before it comes to the final connection by welding over weld beads. Inaccuracies in the positioning of the lid can be corrected in this way before the final welding.

The spacer can be a spacer ring, which ensures a constant equal distance between the cover and the cylinder jacket along the circumference of the drying roller. Likewise, ring segments or separate spacers with a defined width can alternatively be used.

Furthermore, in a method for producing a drying roller at least consisting of a cylindrical cylinder jacket, two on both sides of the cylinder jacket attached lids and two indirectly via a hollow shaft connected to the lids or directly attached to the lids pin, wherein the cylinder jacket and the lid by a annular weld welded together, after welding the cover with the cylinder jacket, the weld through an inspection opening are checked from the inside.

As a result of testing the weld through the inspection opening from the inside, the overall reliability of the weld is increased, since faulty welds can be repaired immediately. Also then a variety of test methods can be used.

Preferably, the radially inner workpiece surfaces of both the lid and the cylinder jacket are cylindrical on both sides of the weld. Such a design of the radially inner workpiece surfaces makes it possible to carry out simple and reliable inspections by means of various inspection devices. Suitable inspection devices may be, for example, X-ray devices or ultrasound devices. In addition, inspections may be performed, for example, by means of dye penetrant tests or magnetic particle inspections or other methods.

It is understood that the features of the solutions described above or in the claims can optionally also be combined in order to implement the advantages in a cumulative manner.

Figur 1

eine schematische Veranschaulichung einer Trockenwalze;

Figur 2

einen Teilbereich der Veranschaulichung der Figur 1;

Figur 3

einen veranschaulichten Teilbereich einer Trockenwalze mit einer Übergangsnut in ähnlicher Darstellung wie Figur 2; und

Figur 4

einen veranschaulichten Teilbereich einer Trockenwalze mit einer stufenförmigen Übergangsnut in ähnlicher Darstellung wie Figuren 2 und 3.

Further advantages, objects and features of the present invention will be explained with reference to the following description of exemplary embodiments, which are shown in particular in the appended drawing. In the drawing show:

FIG. 1

a schematic illustration of a drying roller;

FIG. 2

a subsection of the illustration of the FIG. 1 ;

FIG. 3

an illustrated portion of a drying roller with a transition groove in a similar representation as FIG. 2 ; and

FIG. 4

an illustrated portion of a drying roller with a stepped transition groove in a similar representation as FIGS. 2 and 3 ,

One in the FIG. 1 illustrated essentially cylindrical drying roller 1 comprises a cylinder jacket 2 and two attached on both sides of the cylinder jacket 2 and by means of a in the FIG. 1 In an inner space 4 enclosed by the cylinder jacket 2 and the lids 3, the drying roller 1 further has a hollow shaft 5 extending between the lids 3 and provided with passage openings. On an outer surface of each of the lid 3, a pin 6 is provided in each case. Cylinder jacket 2, cover 3, hollow shaft 5 and pin 6 are arranged coaxially along a longitudinal axis 7, so that the overall result is an axisymmetric structure of the drying roller 1. By means of the pin 6, the drying roller 1 in suitable and in the FIG. 1 Bearings not shown are rotatably mounted about the longitudinal axis 7.

In the operation of the drying roller 1, the outer surface of the cylinder jacket 2 is at least partially wrapped by paper to be dried or paper to be dried is on the Outer surface of the cylinder jacket 2 launched. In the FIG. 1 Not shown pressure rollers press the paper placed against the cylinder shell 2. About the hollow shaft 5 hot steam at a pressure of usually 3 to 8 bar, which may be up to 12 bar or more, passed into the interior 4. There is now a drying process of resting on the cylinder surface 2 paper by means of heat exchange between the hot due to the hot surface in the interior 4 hot surface of the cylinder jacket 2 and the paper instead.

In the FIG. 2 is one in the FIG. 1 Enlarged A portion of the drying roller 1 and enlarged in cross-section, wherein a part of the lid 3 and a part of the cylinder jacket 2 and between these two the above-mentioned weld 8 can be seen. From the FIG. 2 In particular, it is apparent that facing the butt of the weld facing each other facing surfaces of both the lid 3 and the cylinder jacket 2 mutually inclined first flank regions 9 and second flank regions 10 which are mutually parallel and spaced apart. This results in a substantially V-shaped cross section of the weld 8, which widened towards the outside of the cylinder jacket 2 and tapers towards the interior 4, wherein it opens into the interior 4 via a groove-shaped section delimited by the second flank regions 10.

An end portion 11 of the cylinder jacket facing the weld seam 8 is cylindrical in shape on a surface facing the interior space 4, ie. free of elevations or depressions, trained. At this end portion 11, a conical formed as a capacitor 12, the interior 4 towards thickened section with a plurality of circumferentially extending and along the longitudinal axis 7 successively arranged grooves 13 connects. In this case, a transition between the end portion 11 to the capacitor 12 has a transition radius 14.

Also, the lid 3 in the region of the weld 8 to the interior 4 toward cylindrical shape, so that on both sides of the weld 8, the radially inner workpiece surfaces of both the lid 3 and the cylinder jacket 2 are cylindrical.

As a result of opening into the interior 4 out groove-shaped portion, it is possible to provide the weld 8 with a substantially V-shaped cross-section with a counter-bead. In addition, the cylindrical end portion 11 and the both sides of the weld 8 cylindrical radially inner workpiece surfaces of both the lid 3 and the cylinder jacket 2, the weld 8 allows easy visually or by a suitable test method, for example, X-rays or ultrasound, or by means of dye penetrant or magnetic particle checks.

Instead of a V-shaped cross-section, the weld 8 can also be formed with a U-shaped, K-shaped, X-shaped, double U-shaped or other shaped cross-section.

When in the FIG. 3 illustrated embodiment, for the transition from the cylindrical end portion 11 to the capacitor 12 instead of a radius, a circumferential transition groove 15 is formed. Their depth is present equal to the depth of the grooves 13 of the capacitor 12, but it may also have a different depth than the grooves 13th

On the other hand is in the in the FIG. 4 illustrated embodiment instead of the transition groove 15 of FIG. 3 a wide stepped transition groove 16 is formed. Their width is limited only by the width of the end portion 11. Between each of the longitudinal axis 7 perpendicular groove flanks of the transition groove 16 and a parallel to the longitudinal axis 7 groove bottom of the transition groove 16 a transition radius 17 is provided in each case. <B> LIST OF REFERENCES: </ b> 1 drying roll 10 second flank area 2 cylinder surface 11 end 3 cover 12 capacitor 4 inner space 13 groove 5 hollow shaft 14 Transition radius 6 spigot 15 transition groove 7 longitudinal axis 16 transition groove 8th Weld 17 Transition radius 9 first flank area

Claims (4)

1. Drying roller (1), at least composed of a cylindrical cylinder sleeve (2), of two caps (3) which are attached to both sides of the cylinder sleeve (2), and of two journals (6) which are indirectly fastened to the caps (3) by way of a hollow shaft (5) which is connected to the caps (3) or are directly fastened to the caps (3), wherein the cylinder sleeve (2) and the caps (3) are welded to one another by way of an annular weld seam (8), characterized in that the radially inward workpiece face of the cylinder sleeve (2) between a condenser (12) and the weld seam (8) is configured so as to be cylindrical.
2. Drying roller (1) according to Claim 1, characterized in that the condenser (12) has at least one, preferably a plurality of encircling grooves (13).
3. Drying roller (1) according to Claim 1 or 2, characterized in that a machined transitional radius (14) and/or a transitional groove (15, 16) preferably having at least one machined transitional radius (17) between the groove flank of the transitional groove (16) and the groove base of the transitional groove (16) is provided between the cylindrical inward workpiece face of the cylinder sleeve (2) and the condenser (12).
4. Drying roller (1) according to Claim 1, characterized in that the radially inward workpiece faces of both the cap (3) as well as of the cylinder sleeve (2) on both sides of the weld seam (8) are configured so as to be cylindrical.

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