Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F26—DRYING
  • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
  • F26B13/00—Machines and apparatus for drying fabrics, fibres, yarns, or other materials in long lengths, with progressive movement
  • F26B13/10—Arrangements for feeding, heating or supporting materials; Controlling movement, tension or position of materials
  • F26B13/14—Rollers, drums, cylinders; Arrangement of drives, supports, bearings, cleaning
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F5/00—Dryer section of machines for making continuous webs of paper
  • D21F5/02—Drying on cylinders
  • D21F5/04—Drying on cylinders on two or more drying cylinders
  • D21F5/042—Drying on cylinders on two or more drying cylinders in combination with suction or blowing devices
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21G—CALENDERS; ACCESSORIES FOR PAPER-MAKING MACHINES
  • D21G9/00—Other accessories for paper-making machines
  • D21G9/0063—Devices for threading a web tail through a paper-making machine
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F26—DRYING
  • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
  • F26B13/00—Machines and apparatus for drying fabrics, fibres, yarns, or other materials in long lengths, with progressive movement
  • F26B13/06—Machines and apparatus for drying fabrics, fibres, yarns, or other materials in long lengths, with progressive movement with movement in a sinuous or zig-zag path
  • F26B13/08—Machines and apparatus for drying fabrics, fibres, yarns, or other materials in long lengths, with progressive movement with movement in a sinuous or zig-zag path using rollers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F26—DRYING
  • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
  • F26B13/00—Machines and apparatus for drying fabrics, fibres, yarns, or other materials in long lengths, with progressive movement
  • F26B13/10—Arrangements for feeding, heating or supporting materials; Controlling movement, tension or position of materials
  • F26B13/14—Rollers, drums, cylinders; Arrangement of drives, supports, bearings, cleaning
  • F26B13/16—Rollers, drums, cylinders; Arrangement of drives, supports, bearings, cleaning perforated in combination with hot air blowing or suction devices, e.g. sieve drum dryers

Definitions

• the invention relates to a single-screen dryer group, preferably as part of a dryer section for a machine for producing or treating a paper, cardboard or similar web, in particular with the features specified in the preamble of claim 1.
• the web to be dried always runs together with the endless support belt, which is preferably a wire belt.
• the web and the belt run first over one of the drying cylinders and from there over a guide roller to the next drying cylinder etc. .
• the web to be dried is always on the outside of the endless wire belt.
• the web to be dried lies on the drying cylinders between the cylinder surface and the wire belt, i. H. it comes into direct contact with the drying cylinders each time.
• the screen belt is located between the surface of the roller and the web to be dried.
• DE-GM 81 36 028 1 of DE-OS 31 32 040 shows a single-sieve drying group, in which all drying cylinders are arranged at the same height, ie in a single row of cylinders.
• This has the disadvantage that only relatively few drying cylinders can be arranged over a predetermined length.
• FIG. 2 provides for the drying cylinders to be arranged alternately in two parallel rows of cylinders; two rows of cylinders are shown, which extend horizontally and lie at a certain distance above one another. It goes without saying that such a dryer group requires a drive device; however, such is not disclosed in DE-OS 31 32 040.
• WO 87/06635 describes a very similar single-screen dryer group including a drive device.
• This drive device is coupled to the drying cylinders of the upper row of cylinders.
• Such a drive device has the disadvantage that two different bearing journals must be provided on each of the driven drying cylinders, namely a relatively short bearing journal on the driver side and a longer journal on the drive side.
• the drive energy must be transferred from the drying cylinder to the drying wire via the paper web.
• DE-GM 81 36 028 describes a two-wire dryer group with different drive devices.
• these drive devices it is provided that only the guide rollers are driven, the guide rollers of a drying group being coupled to one another by means of spur gears which are in direct engagement with one another.
• spur gears which are in direct engagement with one another.
• the object of the invention is to design a single-screen dryer group in such a way that at least a considerable part of the drive power can be supplied via some of the guide rollers. It goes without saying that the construction effort required for this should be kept as low as possible.
• it is desirable that the overall length of the drying group (for a certain number of drying cylinders) is as short as possible.
• the invention cleverly utilizes the fact that - when the drying cylinders are arranged alternately in two parallel rows of cylinders - at least one so-called cylinder-three group is formed, to which two closely adjacent guide rollers belong.
• These two guide rolls which form a pair of guide rolls, can now be coupled to one another by a simple gear transmission and connected to a drive motor. Since the two guide rollers always have the same direction of rotation, the said gear must have an odd number of meshing gears. In most cases, you will only need three gears, with the two outer gears sitting on the guide rollers.
• the drive motor is preferably coupled to the central gearwheel, which is in engagement with the two outer gearwheels.
• the single-screen dryer group according to the invention will generally be designed in such a way that the entire drive takes place exclusively via guide rollers (claim 2).
• This has the advantage that the rotating endless screen belt is driven by rollers that have direct contact with the screen belt.
• the paper web speed can thus be precisely controlled, since the paper web has very intensive contact with the wire belt.
• the two rows of cylinders are arranged one above the other at a relatively large distance, which is approximately equal to the cylinder diameter.
• the guide rollers must be designed as suction rollers, because in their area the paper web lies on the outside of the support belt and must be held against the support belt by means of negative pressure against the centrifugal force .
• the overall arrangement described in claim 3 makes it possible to provide sufficient space in the "pocket” (which is delimited by two adjacent drying cylinders and by the guide roller lying in between) for a so-called external suction box. This can preferably be designed in accordance with the parallel application P 39 10 600.4 (Akz. P 4618).
• an external suction box is that one does not have to lead the suction line through the roller pin (and thus possibly through the drive device). Rather, a simple drive pin can be provided as an extension of the bearing pin for driving the roller, and besides (also at the drive end) a separate suction line to the external suction box can be excluded. A modification of this idea is described below.
• the driven suction guide rollers preferably have perforated roller shells, there is a relatively high frictional adhesion between the driven roller jacket and the belt. It was known that this frictional adhesion remains approximately constant over the entire speed range. The desired paper web speed is thus maintained much more precisely than when the drying group is driven via the drying cylinders. Because, as is known, the drying cylinders have a very smooth outer surface. In addition, the paper web is always between the cylinder surface and the screen belt. As a result, the frictional adhesion between the cylinder surface and the sieve belt is significantly lower. On the other hand, the fact that the paper web always runs synchronously with the air-permeable and rough surface belt is used in the direct drive of the fabric belt via the suction guide rollers.
• Figure 1 shows a schematic side view of part of the dryer section of a paper making machine.
• FIG. 2 shows a partial cross section along line II of FIG. 1 (on an enlarged scale).
• FIG. 3 shows a modification of FIG. 1.
• FIG. 4 shows a partial cross section along line IV of FIG. 3.
• a paper web 9 to be dried is shown in FIG. 1 with a dotted line.
• the paper web passes through a roller press 10, then a first drying group 20 and is then passed on to a second drying group 40, which is only partially visible.
• the press nip of the roller press 10 is located in the lower region of a smooth press roller 11.
• the paper web 9 runs upwards behind this press nip on the smooth roller 11 and from there onto a paper guide roller 12.
• the first dryer group 20 is a so-called single-screen dryer group; i.e. it has a single, endless support belt 8, preferably in the form of a sieve belt.
• This support belt 8 unites on the paper guide roller 12 with the paper web 9 to be dried and guides the paper web through the entire drying group 20.
• Support belt 8 and paper web 9 together first via a guide roller 13 (located within the support belt loop), then via the following cylinders and rollers:
• the drying cylinders 21-24 are located outside the support belt loop 8, on the underside of the latter.
• the suction guide rollers 31-34 are all within the support belt loop.
• the paper web 9 is taken over by the support belt 48 of the second dryer group 40.
• Support belt 48 and paper web 9 run therein together first over a suction guide roller 51, then over a drying cylinder 41, a suction guide roller 52 and over a drying cylinder 42. Further suction guide rollers and drying cylinders follow. but no longer shown in the drawing.
• the drying cylinders are outside and the suction guide rollers inside the support belt loop 48.
• the drying cylinders 41 and 42 are on the top of the support belt 48. Therefore, in the first Drying group 20 one side of the paper web 9 in contact with the drying cylinders 21-24; in the second drying group 40, on the other hand, the other paper side comes into contact with the drying cylinders 41-42.
• the drying cylinders are alternately arranged in two parallel rows of cylinders, between which there is a distance h. Overall, however, the drying cylinders of the first group 20 are arranged higher (above the machine floor) than the drying cylinders of the second drying group 40.
• the first drying group 20 comprises a total of four drying cylinders. However, this number can easily be varied upwards or downwards.
• Figure 1 also shows that the suction guide rollers are always arranged in pairs.
• the first and second suction guide rollers 31 and 32 form a pair of guide rollers which are arranged at a relatively short distance from one another.
• This pair of guide rollers 31 and 32 lies between the drying cylinders 21, 22, 23 of a so-called group of three cylinders.
• This group of three is formed by two adjacent cylinders 21 and 23 of the lower row of cylinders and by a middle cylinder 22 which belongs to the upper row of cylinders.
• the first single-screen dryer group is driven solely by the suction guide rollers 31-34.
• each guide roller pair is assigned a gear transmission 35, which comprises a housing and three intermeshing spur gears.
• the two outer gears 36 and 37 sit on the guide roller drive pins (for example 32 "in FIG. 2) which are mounted in the gear housing 35 are.
• the central gear 38 has a drive pin 39 to which a motor can be coupled.
• a bearing 19 for a scraper 18 can be arranged on the gear housing 35 (omitted in FIG. 2).
• the two suction guide rollers 33 and 34 are also coupled to one another by a gear transmission, which can be designed identically to the gear transmission 35.
• a gear transmission which can be designed identically to the gear transmission 35.
• Another Zahnradge ⁇ gearbox of the same type can be used to drive the suction guide rollers 51 and 52.
• this gear it is expedient to arrange this gear in a position rotated by 180 °; because it is expediently attached to the underside of a side member, not shown in FIG. 1.
• All suction guide rollers 31-34 and 51 and 52 have an external suction box 17 instead of an internal suction box. This avoids that suction lines have to be led through the gear 35 or that the suction box on the drive side is in a special inside the roller lying and therefore not accessible from the outside additional bearings.
• the drive ends of the suction guide rollers 31 and. 32 stored in the gear housing 35. Deviating from this, normal bearings 35 separate from the transmission could also be provided. In this case the gear would have to be arranged at a somewhat greater distance from the guide rollers and connected to them via couplings. In all cases, as shown, the two guide rollers of a pair of guide rollers will be arranged horizontally next to one another, so that the gear housing 35 can be formed in a simple manner with a horizontal parting line.
• the drying cylinder 22 rests at its drive end in a bearing 16 which is fixed above the gear 35 on a side member 14.
• the vertical distance h between rows of cylinders is preferably less than half the cylinder diameter.
• the suction guide rollers 32 preferably have a perforated roller jacket.
• the roller shell can instead be provided with circumferential grooves.
• the guide rollers 12 and 13 are shown as normal, smooth guide rollers.
• the guide roller 13 can also be designed as a suction guide roller, preferably just like the other suction guide rollers with an external suction box.
• the guide roller 12 can also be designed as a suction guide roller, but preferably with an internal suction box.
• FIG. 3 shows the same arrangement of the drying groups 20 and 40 as in FIG. 1. Only the external ' suction boxes 17 of FIG. 1 are omitted, and the suction guide rolls are now designated 31' to 34 'as well as 51' and 52 '.
• the suction guide rolls still have no internal suction box, but instead a hollow roll neck 32a (FIG. 4) and a suction line 32c attached to the bearing housing 32b at the driver's end.
• the required negative pressure is primarily generated in the interior of the suction guide rolls.
• This internal pressure propagates through the bores of the roller jacket to the entire circumference of the guide roller body, that is to say on the one hand to the part of the roller roller wrapped by the support belt 8 and the paper web 9 and on the other hand to the so-called pocket which is delimited by the guide roller in question, for example 32 ', the two adjacent drying cylinders 22 and 23 and the support band 8.
• a prerequisite for the creation of a negative pressure in the pocket mentioned is that a seal carrier 47 is preferably arranged outside the pocket and extends parallel to the drying cylinders extends through the entire drying group 20.
• This seal carrier 47 has, for example, sealing strips 48 and 49 at the narrowest point between the two drying cylinders 22 and 23, which lightly touch the support band 8 or are arranged at a small distance from the support band.
• one of the Suction guide rollers 31 'to 34' and 51 ', 52' assign such a seal carrier. In Figure 3, only a single seal carrier is shown, the rest are omitted. The seal carrier is also omitted in FIG
• each of the pockets is also closed at their two ends (i.e. on the two edges of the support band 8) by side walls (indicated schematically in FIG. 4 at 50).

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Paper (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6377646

Family Applications (1)

Country Status (2)

Cited By (3)

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Citations (4)

Family Cites Families (3)

• 1989
  • 1989-04-01 DE DE19893910612 patent/DE3910612A1/de active Granted
• 1990
  • 1990-03-30 WO PCT/EP1990/000505 patent/WO1990012150A1/de unknown

Patent Citations (5)

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