Classifications

• • 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
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21G—CALENDERS; ACCESSORIES FOR PAPER-MAKING MACHINES
  • D21G1/00—Calenders; Smoothing apparatus

Definitions

• the invention concerns a web finishing section in a paper machine, which finishing section comprises at least a dryer section composed of one or several dryer groups, a calender, and a reel-up.
• the web has long, substantially free or unsupported draws, which increases the length of the finishing section in the paper machine to a substantial extent and requires threading ropes for the threading of the leader of the web.
• various quality measurement devices are fitted for measurement and monitoring of the quality of the paper web. Costs have, of course, also arisen from the paper guide rolls required by the draws.
• the long draws of the paper web have also required threading ropes and related arrangements of equipment and equivalent, by whose means the leader of the paper web is carried during threading from one stage into the other, which has increased the costs of equipment further.
• the object of the invention is to provide a finishing section for a paper machine in which the problems described above have been eliminated or at least minimized.
• the finishing section in a paper machine in accordance with the present invention is mainly characterized in that the calender is placed at least partly underneath the reel spool storage space of the reel-up so that the reel-up is placed substantially directly after the calender, in which case the web is passed directly from the calendering nip onto the reel cylinder or to a substantially short distance from the calender, the web being passed over one guide member that supports and/or spreads the web onto the reel cylinder.
• the arrangement in accordance with the present invention permits a ropeless threading, because there are no long unsupported draws, in which case, for threading, it is possible to use, for example, guide plates and/ or equivalent suitable for full- width transfer of the web.
• ropeless threading can be arranged particularly simply so that the web is passed from the last drying cylinder in the dryer section by means of guide plates or equivalent directly onto the belt in the belt calender, on whose belt the web is passed through the calendering nips and further onto the belt in the belt reel-up.
• One belt calender is described in the applicant's FI Patent Application No. 931021, and one application of a belt reel-up is described in the applicant's FI Patent Application No. 935669.
• the finishing section By means of an arrangement in accordance with the invention, considerable economies of length are obtained in the finishing section, which economies of length correspond, for example, to a distance in which a group consisting of six drying cylinders can be accommodated, in which case the capacity of the dryer section can be increased without changing the overall length of the machine.
• the production rate can be increased, for example, from 615 tons to 735 tons per day, or the speed from 1500 metres per minute to 1800 metres per minute, which corresponds to an increase in production of about 16 per cent.
• the short web draws after the calender permit a full-width threading of the web based on a what is called coanda effect, because the exclusively airborne support and guiding of the web, which is difficult to control over unduly long distances, can be reduced to the minimum.
• cooling of the web is needed between the calender and the reel-up, it is possible to use various cooling devices in themselves known, such as a blow box.
• Figure 1A is a schematic illustration of a prior-art arrangement, in which the last group in the dryer section is a dryer group with twin-wire draw.
• Fig. IB the finishing section shown in Fig. 1A is illustrated schematically as an arrangement in accordance with the present invention.
• Figure 2A is a schematic illustration of a prior-art arrangement of a finishing section in a paper machine, wherein the last group in the dryer section has been arranged as a group with single- wire draw, and
• Figure 2B is a schematic illustration of the finishing section of Fig. 2 A in a paper machine, wherein an arrangement in accordance with the present invention is used.
• the last dryer group RA N in the dryer section in the finishing section makes use of twin-wire draw, after which group the web is passed as a draw 26 A to the soft calender 20 A, which is followed by a second draw 25A, supported by paper guide rolls 27A, to the reel-up 30A.
• the pulpers 41 A and 42 A of the dryer section and of the reel-up are placed below the machine level in the so-called basement space.
• the wires 10A,11A run, being guided by the guide rolls 16A,17A, over the drying cylinders 12A,13A and the reversing rolls 14A,15A in the mode of twin-wire draw. Between the rows of drying cylinders 12 A, 13 A the web has free draws.
• the paper web is passed over the guide roll 28 A as the draw 26 A into the first calendering nip NNi in the calender 20A, from which the web is passed further into the second calender- ing nip NA 2 , and from there as the draw 25 A over the guide rolls 27 A to the reel-up 30 A, whose storage space for reel spools is denoted with the reference numeral 33 A, the reel spool change devices with 34A, the reel cylinder with 31 A, and the paper reel that is being formed with the reference 32A, and the complete machine reel with the reference 35A.
• the length of the finishing section in the paper machine has been made shorter so that the draws 26A,25A between the last dryer group R N and the soft calender 20 and between the soft calender 20 and the reel-up 30 have become substantially shorter.
• the reel spool storage space 33 of the reel-up 30 is placed above the soft calender 20, and the pulpers of the dryer section and of the reel-up have been combined as a single pulper 41.
• the drying wires are denoted with the reference numerals 10,11, and they run, guided by the guide rolls 16,17, over the drying cylinders 12,13 and the reversing rolls 14,15. Between the rows of drying cylinders 12,13 the web has free draws.
• the web is passed as a short draw over the roll 28 into the first calender nip N j in the calender 20, from which it is passed into the second calender nip N 2 .
• the web is passed over the reel cylinder 31 to be reeled as the paper reel 32.
• the reel spool storage space in the reel-up 30 is denoted with the reference numeral 33, the reel spool change device with the reference 34, and the complete machine reel with the reference 35.
• economies of length are achieved in the arrangement in accordance with the invention.
• economies of length L j in a transition from an arrangement as shown in Fig. 1A into an arrangement as shown in Fig. IB are 7650 mm.
• Fig. 2 A is a schematic illustration of a prior-art arrangement for a finishing section in a paper machine, in which the last dryer group RA N in the dryer section is a dryer group with single-wire draw.
• the pulper 41 A of the last dryer group RA N is placed in the basement space.
• From the last dryer group RA N the paper web is passed as the draw 26 A to the soft calender 20A, where it is calendered from both sides in calendering nips NA l 5 NA 2 , after which the web is passed to the reel-up 30A, where a machine reel 32A,35A is formed out of the web.
• the drying wire is denoted with the reference numeral 50A
• the wire guide rolls are denoted with the reference 51 A
• the drying cylinders with the reference 52A and the vac rolls in the lower row with the reference 53A.
• the paper web to be dried runs, in the single-wire draw, from the drying cylinders 52 A onto the reversing rolls 53 A while constantly supported by the drying wire 50 A. After this, the run of the web further is similar to the arrangement shown in Fig. 1A.
• a quality measurement device 29 A is fitted between the calender 20A and the reel-up 30A.
• the finishing section in the paper machine has been made shorter in accordance with the invention, in which connection the draw 26 from the dryer section to the soft calender 20 has been made slightly shorter and the draw from the soft calender 20 to the reel-up 30 has been eliminated completely as the reel spool storage space 33 in the reel-up 30 has been placed above the soft calender 20, whereby considerable economies of space have been achieved.
• the dryer group R N is a dryer group with single- wire draw, in which the paper web runs on the support of the drying wire 50 from the drying cylinders 52 in the upper row onto the vac rolls 53, which are placed in the lower row.
• the wire 50 guide rolls are denoted with the reference numeral 51.
• the draw in the final part of the finishing section is substantially similar to that described above in relation to Fig. IB.
• the economies of length L2 that are achieved are, for example, 6300 mm.
• the upper roll of the second nip N 2 in the soft calender 20 can be raised from the machine directly upwards through the reel spool storage space 33, which results in an easy and quick replacement of the roll, i.e. the production efficiency of the machine is increased as the time taken by the change of roll becomes shorter.
• parts for example latches or equivalent, are opened and permit lifting of the roll through the frame system of the reel spool storage space 33.
• the frame system of the reel spool storage space 33 is supported on the floor level by means of columns of its own from outside the frame system of the soft calender 20 in order to avoid detrimental effects of oscillations in the soft calender 20.
• the frame system is supported from both of its ends in the machine direction.
• easy and quick change of roll is achieved in the soft calender 20, and oscillation-free storage 33 is obtained for the reel spools.
• Spreading of the effects of formation of dust that may occur in the reel- up 30 to the calender 20 is prevented by, if necessary, constructing an air jet and/or a detachable shield wall (not shown) between the calender 20 and the reel-up 30.
• a quality measurement beam is constructed between the columns placed between the calender 20 and the reel-up 30 in an integrated way in consideration of attenuation of vibrations.
• just one pulper 41 is needed, which is installed so that the web can be passed from the dryer section R N , from the calender 20 and from the reel-up 30 into the pulper.
• the chutes 45 of the pulper 41 are designed sufficiently long and, if necessary, the pulper 41 is mounted sufficiently far down below in order to provide an inclination downwards.
• the frame of the reeling equipment 30 is separate from the frames of the reel spool storage space 33 and of the calender 20, in which case vibrations and resonance of different components are avoided.
• Figs. IB and 2B some preferred exemplifying embodiments are illustrated of the web finishing section in accordance with the invention in a paper machine.
• This is, of course, not supposed to confine the invention to such finishing sections alone, but variations of many other, different types are also possible.
• the dryer groups can be con- structed, for example, by employing a dryer concept based on the heat pipe effect (CONDEBELT), by means of airborne web dryers, dryers based on infrared radiation, etc.
• CONDEBELT heat pipe effect
• the reel-up and the calender shown in the figures can also differ from the embodiments illustrated in the figures.

Landscapes

• Paper (AREA)
• Folding Of Thin Sheet-Like Materials, Special Discharging Devices, And Others (AREA)
• Diaphragms For Electromechanical Transducers (AREA)
• Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
• Professional, Industrial, Or Sporting Protective Garments (AREA)
• Surgical Instruments (AREA)
• Orthopedics, Nursing, And Contraception (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=8548328

Family Applications (1)

Country Status (7)

Families Citing this family (5)

Family Cites Families (3)

• 1997
  • 1997-03-03 FI FI970904A patent/FI102093B/fi active
• 1998
  • 1998-02-27 AT AT98905451T patent/ATE212394T1/de not_active IP Right Cessation
  • 1998-02-27 JP JP10538204A patent/JP2000509775A/ja active Pending
  • 1998-02-27 DE DE69803523T patent/DE69803523T2/de not_active Expired - Fee Related
  • 1998-02-27 WO PCT/FI1998/000181 patent/WO1998039515A1/fr active IP Right Grant
  • 1998-02-27 AU AU61031/98A patent/AU6103198A/en not_active Abandoned
  • 1998-02-27 EP EP98905451A patent/EP0901535B1/fr not_active Expired - Lifetime

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events