FI62154C - TRUMMA WITH RINGFORMED GALLERY STRUCTURE SAERSKILT FOER TORKNING AV EN PAPPERSBANA - Google Patents

Description

RSSr ^ l [B] (11) ANNOUNCEMENT Q

flHA l J '' UTLÄGGNINGSSKRIFT 6z154 5¾¾¾ c (45) Patent .nyd ;;;.: tty 10 11 1932 0 Patent neddelat (51) K ».lk? /int.ci.3 D 21 F 5/02, F 26 B 15/16 FINLAND —FINLAND (21) Ptt * nKllwk «mM-NiMtiM» knlni 2726/73 (22) Hakwnltpllvl —Amdkiiln | * 4i (31 · 08.73 * * (23) Alkupllvt — Glltl | h «ti4i | 31.08. 73 (41) Tulkit lulklMkal - ftllvlt off «mll | I6.O3.7I + FManttl · Jft r« kl «tflh» llltu «(44) Nlhtlvikilpcnen 1» luwl.) Ullul.urt pvm. -

Fsfctnt- och rt | littntyrtlnn Antökin utlifd «eh utl.ikrifun pubticend 30.07.82 (32) (33) (31) W · ** / muoHum —UgM prior * ·· * 15.09.72 USA (US) 289663 (71) Improved Machinery, Inc., Delaware, US; Burke Street, Nashua, New Hampshire, USA (72) Oscar Luthi, Nashua, New Hampshire, USA (7 * 0 Berggren Oy Ah (5 * 0 Drum with annular lattice structure especially for drying paper web - Trumma med ring-shaped collar structure, särskilt för torkning av en pappershana

The present invention relates to a drum, in particular for drying a paper web, comprising an annular lattice structure attached to the end of the drum and consisting of adjacent strips attached to each other in the lateral direction. Such drums are used, for example, in the pulp and paper industry.

Drums of this general type are normally well suited for drying paper webs due to their large proportion of open circumferential surface and structural rigidity. In a dryer incorporating such a drum, the paper web can be run circumferentially around the grid structure under a support felt passing therethrough, while air at very high temperatures (e.g., 370-480 ° C) is blown outward from inside the drum through the grid structure and the paper web and support felt thereon. .

The device of this construction has one or more cooling jets which automatically direct coolant (e.g. at a temperature of about 16 ° C) to the lattice structure in case the paper web breaks, which prevents the support felt from scorching which would otherwise occur when the felt comes into contact with the lattice structure 2 62154 has failed. Thus, in such devices, the lattice structure is cooled by the cooling of the paper web, suddenly from about 370 ° C, and it is clear that rapid cooling of the lattice structure from 370 ° C to 16 ° C causes a 1.2 cm reduction to 200 cm. in a diameter lattice structure.

Despite this cooling of the lattice structure, however, the drum end plates remain at full operating temperature for some time, causing the lattice structure to warp and result in such poor deflection and retraction near the junction of the end plates and lattice structure that it eventually results in premature drum breakage. In addition, although the end plates of the drum remain hot after cooling the lattice structure, the stiffening coils along the end plates cool, forming another cause of distortion and premature breakage.

Alternatively, in a dryer incorporating a drum of the type described above, the paper web may be run around the lattice structure under a forced wire covering it, while air at the above very high temperature is blown inward through the wire, web and lattice structure and removed from the drum interior at a greatly reduced temperature. about 92 ° C). In this arrangement, the lattice structure after the paper web is broken is suddenly exposed to air at a temperature much higher than 92 ° C, which causes problems similar to the rapid cooling of the lattice structure described above.

It is an object of the present invention to provide a new type of drum with an annular lattice structure which is specially constructed and adapted to withstand temperature fluctuations of up to several hundred degrees without excessive distortion, retraction or breakage. The features of the invention appear from the following claims.

The invention is illustrated below by explaining the accompanying drawing with reference to a preferred embodiment of the invention.

3 62154

In the drawing: Fig. 1 is a view schematically showing a drum according to an embodiment of the invention; Fig. 2 is an enlarged fragmentary perspective view of the drum of Fig. 1; Fig. 3 is an enlarged partial plan view showing a second end portion of the lattice structure of the drum; Fig. 4 is an enlarged elevational view showing the second end plate of the drum and associated stiffening sides; Fig. 5 is an enlarged sectional view taken along line 5-5 of Fig. 4 in the direction of the arrows; Fig. 6 is an enlarged fragmentary sectional view taken along line 6-6 of Fig. 5, seen in the direction of the arrows, and Fig. 7 is an enlarged fragmentary sectional view taken along line 7-7 of Fig. 5 in the direction of the arrows.

According to a drawing in which the same parts are used in different figures to denote corresponding parts, the drum comprises an annular, cylindrical honeycomb structure 10 having circumferential end portions, each generally indicated by reference numeral 12, and a circumferential spacer 14 with the end piece 12 therebetween. in the same paragraph. The relative lengths of the end portions 12 and the intermediate portion 14 in the axial direction of the truss structure 10 can, of course, be varied in different embodiments of the truss structure 10. It should be noted, however, that the length of each end portion 12 is preferably only a relatively small portion of the total length of the lattice structure 10. For example, in a lattice structure 10 having a length of about 275 cm, the length of each end portion 12 may be about 15 cm, with the intermediate portion 14 forming a remaining portion of the lattice structure 10 of about 245 cm.

The end portions 12 are completely similar in structure and comprise only a corrugated or non-planar sheet metal strip material 16, twisted into a helical shape so as to be longitudinally parallel to the circumferential structure of the lattice structure 10, the adjacent turns of corrugated strip material 16 being immediately laterally connected to each other. The corrugated strip 16 is arranged so that its largest transverse or widthwise dimension is at least approximately radial to the lattice structure 10, and adjacent interconnected turns 4 62154 of the corrugated strip 16 together form openings 18 extending at least approximately radially transversely. through the thickness. The corrugated strip material 16 itself can be of any suitable corrugated or non-planar shape, and preferably, as in the drawing, the structure described in Finnish patent application 2725/73.

More specifically, the corrugated strip material 16 includes, as shown in the drawing, alternately transverse portions 20 and connecting portions 22 extending across the median plane of the corrugated strip material 16 and the closest connecting portions 22 being on opposite sides of said median plane. The connecting portions 22 are curved and pointed in shape, and each of them, together with the transverse portions 20 on opposite sides thereof, forms an approximately V-shaped portion of the corrugated strip material 16. Thus, the connecting portions 22 form the pointed peaks of said V-shaped portions.

Each connecting part has one or more expanded parts 24, of which the adjacent turns of the corrugated strip material 16 are connected to each other, e.g. by welding.

The intermediate portion 14 of the lattice structure 10 includes both the corrugated strip material 16 described above and also the planar sheet metal strip material 26. The corrugated and planar strip materials 16, 26 are wound in a helical shape so as to be alternately arranged circumferentially along the circumferential size of the intermediate portion 14. length and rigidly attached to each other (e.g., by welding) at the expanded portions 24 of the joint portions 22 of the corrugated strip material 16. The alternately arranged strips 16, 26 are in such a position that their maximum transverse or width dimension is at least approximately radial to the lattice structure 10, and together they define the openings 18 at least approximately parallel to the radius of the lattice structure 10 through this thickness. Thus, the intermediate portion 14 comprises alternating turns of strips 16 and 26 along its entire length, of which the substantially adjacent ones are rigidly connected laterally to each other at spaced apart points. The end turns of the intermediate part 14 are, of course, each similarly rigidly connected at spaced points to the end turn of the respective end part 12 adjacent to this turn.

62154 5

As shown in the drawing, each end of the lattice structure 10 is supported by a support member, generally indicated at 28, comprising an approximately radial wall 32 to which the end turn 30 of the adjacent end 12 is attached, preferably by welding, from its expanded portions 24. Each support member 28 further comprises a support ring, i.e. an annular plate 34, which is integral with the wall 32 and has an outer diameter approximately equal to that of the lattice structure 10.

At each end of the drum there is an annular end plate 36 which, as in the drawing, can close the corresponding end of the lattice structure 10. Each end plate 36 is fixed on its outer circumference to the support ring 34 of the respective support member 28, and its inner circumference is rigidly connected to a hub, i.e. a hub structure, generally designated 38, consisting of a plurality of annular hub members 40, 42, 44 and 46. Each annular hub member 44 is welded or otherwise immediately attached to the inner circumference of the respective end plate 36 and rigidly supporting an annular hub member 42 projecting toward the interior of the drum coaxially with the lattice structure 10, and rigidly supporting a hub member 46. Each hub member 44 is further secured to the hub member 40 by a plurality of bolts 48. provided with approximately radial ribs 40a, and supports a pin shaft 50 rotatably adapted to support the corresponding end of the drum.

A plurality of stiffening halves 52 are arranged along each end plate 36 inside the drum to provide the necessary rigidity to the end plate 36. More specifically, and as shown in Figures 4 and 5, the spools 52 are each arranged approximately longitudinally to the end of the lattice structure 10 and the drum. and their inner ends 54 are fixed approximately in the center of the end plate, e.g. by welding to the hub members 42, 44 and 46 so that the inner end 54 of each spool 52 is rigidly attached to the inner end of the respective end plate 36 via the hub structure 38. The outer ends 56 of the spools 52 are located close to the inner circumference of the truss structure 10, but inwardly from the respective support member 28 that the spools 52 can accommodate in their longitudinal direction to expand in the radial direction of the truss structure 10. The outer ends 56 of the spools 52 further support each mounting bracket 58, with holes 60 on each side 621 54e of the spool 52 extending with corresponding holes 62, 64 in the end plate 36 and the end plate 36, respectively. The holes 60, as shown in Figures 5 and 6, are each quite larger in diameter than the holes 62, 64 extending with them. Fastening bolts 68 are inserted through the extending sets of holes 60, 62, 64 to secure the outer ends of the halves 52 to the end plates 36. The holes 60 of the bolts 68 the portions 70 at are substantially smaller in diameter than the holes 60 so that the end plates 36 and spools 52 have limited movement relative to each other approximately radially of the lattice structure 10 to allow the radial expansion and contraction of the end plates 36 and halves 52 to varying in size.

Between the inner end 54 and the outer end 56 of each spool 52 is a rigidly supported mounting plate 72 which, together with the mounting members 74, ensures that the spool 52 properly abuts the end plate 36 but allows the end plate 36 and spool 52 to expand and contract approximately radially. Between the points where the spools 52 are fixed to the end plates 36 by the fixing plates 72 and fixing members 74 and the ends 54 and 56 of the spools 52, the spools 52 are not fixed to the end plates 36. To facilitate relative movement of the spools 52 and end plates 36 approximately radially in the lattice structure 10 and during shrinkage, a suitable lubricant is further applied between each reinforcement 66 and the mounting bracket 58.

Although only one embodiment of the invention is shown in the drawing and described in detail above, the invention is of course not limited to this single embodiment, but encompasses other embodiments within the scope of the following claims.

Claims (5)

A drum, in particular for drying a paper web, comprising an annular lattice structure (10) attached to the end of the drum, consisting of adjacent laterally attached strips, characterized in that the strips at least in the parts (12) of the lattice structure (10) close to the drum end comprise only a material (16) and that the part (14) between these parts (12) of the lattice structure (10) comprises both corrugated (16) and planar (26) strip material. Drum according to Claim 1, characterized in that the strips (16, 26) are circumferentially parallel to the lattice structure (10). Drum according to claim 1 or 2, characterized in that the lattice structure (10) comprises a plurality of said end portions (12) comprising only corrugated strip material, these portions (12) being separated by both corrugated (16) and planar ( 26) a strip-containing part (14). Drum according to one of Claims 1 or 2, characterized in that only the end parts (12) at the opposite ends of the lattice structure (10) closest to the end of the drum comprise a corrugated strip material (16). ' Drum according to one of the preceding claims, characterized in that the turns of the circumferential corrugated strip (16) in the longitudinal direction of the end parts (12) of the lattice structure (10) are fastened only laterally to one another and that the turns between them comprise alternately corrugated (16) ) and a planar (26) strip are similarly attached only laterally to each other.