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

Definitions

• This invention relates to an apparatus for sequentially drying both sides of a paper web. More particularly, this invention relates to a BEL RUN type drying section in which a first drying section dries one side of the web and then a subsequent drying section dries the opposite side of the web.
• the single felt section may be made up of four groups of rollers.
• these groups include drying rollers and suction rollers which provide no open draw in their configuration because the paper web is always supported by a dryer felt.
• the same side of the web is always presented to the successive drying rollers.
• the present invention seeks to overcome the afore ⁇ mentioned problems associated with the BEL RUN and other single-felted dryer section configurations by providing a web transfer section defined by a first and second felt such that the web is sandwiched between the felts during passage through the transfer section so that during movement of the web around a subsequent drying roller, the opposite side of the web comes into physical contact with the heating surface of the subsequent drying roller.
• Another object of the present invention is the provision of an apparatus in which a first felt is a continuous loop which extends in sinusoidal configuration past alternate drying and suction rollers and in which the second felt is a continuous loop which extends in sinu ⁇ soidal configuration past alternate drying and suction rollers such that the first plurality of drying rollers physically contacts the first side of the web and the second plurality of drying rollers physically contacts the second side of the web so that alternate sides of the web are sequentially dried.
• Another object of the present invention is the provision of a method of sequentially drying alternate sides of the web which includes guiding a joint run of the web and a first felt around a first drying roller such that the web is sandwiched between the first felt and the first drying roller for heating a first side of the web.
• the joint run is thereafter guided around a first suction roller such that the first felt is sandwiched between the web and the first suction roller.
• a second felt is guided from a second guide roll around a second suction roller such that the first and second felt define therebetween a web transfer section so that the web, supported by the first felt, is guided into the web transfer section with the web being disposed between the first and second felts, drawing the web emerging from the web transfer section around the second suction roller such that the second felt is disposed between the web and the second suction roller and thereafter directing the joint run of the web and the second felt around a second drying roller such that the web is sandwiched between the second felt and the second drying roller for heating a second side of the web.
• the apparatus includes a first drying roller in which the web extends around a portion of the circumference of the first drying roller.
• the first felt extends around the portion of the first drying roller such that the web is sandwiched between the first felt and the first drying roller for heating a first side of the web.
• a first suction roller is disposed downstream relative to the first drying roller with the first suction roller having an axis of rotation disposed parallel and spaced relative to the rotational axis of the first drying roller.
• the first felt and the web extend around a portion of the circumference of the first suction roller such that the first felt is sand ⁇ wiched between the web and the first suction roller.
• a first guiding means guides the first felt away from the first suction roller and a second suction roller is disposed adjacent to the first suction roller with the second suction roller having an axis of rotation parallel and spaced relative to the axis of rotation of the first suction roller.
• a second felt extends around the second suction roller and a second guiding means guides the second felt towards the second suction roller such that the first and second felts define therebetween a web transfer section so that the web is sandwiched between the felts during passage through the transfer section.
• a second drying roller is disposed downstream relative to the second suction roller with the second drying roller having an axis of rotation parallel to the axis of rota ⁇ tion of the second suction roller such that the web is sandwiched between the second felt and the second drying roller for heating a second side of the web.
• the first felt is a continuous loop which extends in sinusoidal configuration past alternate first drying and suction rollers.
• the second felt is a continuous loop which extends in sinusoidal configuration past alternate second drying and suction rollers such that the first drying rollers physically contact the first side of the web and the second drying rollers physically contact the second side of the web so that alternate sides of the web are sequentially dried.
• the first guiding means includes a first guide roll for guiding the first felt and the second guiding means includes a second guide roll for guiding the second felt.
• the present invention also includes a method for sequentially drying alternate sides of a paper web wherein the method includes the steps of guiding a joint run of the web and a first felt around a first drying roller such that the web is ' sandwiched between the first felt and the first drying roller for heating a first side of the web. Thereafter, the joint run of the web and first felt is guided around a first suction roller such that the first felt is sandwiched between the web and the first suction roller.
• the first felt is then guided around a first guide roll and a second felt is guided from a second guide roll around a second suction roller such that the first and second felts define therebetween a web transfer section so that the web supported by the first felt is guided into the web transfer section with the web being disposed between the first and second felts.
• the web emerging from the web transfer section is drawn around the second suction roller such that the second felt is disposed between the web and the second suction roller.
• the joint run is directed around a second drying roller such that the web is sandwiched between the second felt and the second drying roller for heating a second side of the web.
• Figure 1 is a side-elevational view of a prior art
• BEL RUN type drying section showing the first four groups of drying rollers drying a first side of a paper web.
• Figure 2 is a side-elevational view of a BEL RUN type drying configuration according to the present invention showing the means for transferring the web without open draw from a first to a second felt, and
• Figure 3 is an enlarged side-elevational view of figure 2 particularly showing, in detail, the web transfer section enabling the opposite side of the web to come into physical contact with a subsequent group of drying rollers. Similar reference characters refer to similar parts throughout the various figures of the drawings.
• Figure 1 is a side-elevational view of a conventional
• BEL RUN type drying section including groups A,B,C and D for drying a web of paper 1.
• the web 1 is guided in sinusoidal configuration around a plurality of drying rollers 2, 2' and 2" and suction transfer rollers 3, 3' and 3".
• a first felt 4 loops around a plurality of guide rolls 5, 5',5",5"' and 5"" and supports the web 1 as the web moves alternately past drying and suction rollers 3, 2, 3', 2', 3" and 2".
• a second group B of drying rollers 6, 6", and 6" have suction rollers 7, 7' and 7" disposed alternately therebetween such that a second felt 4' loops around the suction and drying rollers 7, 6, 7', 6', 7" and 6" in sinusoidal configuration.
• the web 1 is unsupported by the felt 4 as the web 1 supported by the drying roller 2" rotates adjacent to the second felt 4 1 so that the web 1 is transferred to the second felt 4" and around the suction roller 7.
• the same side 8 of the web 1 is brought into contact with the heating surfaces of the drying rollers 2, 2', 2", 6, 6' and 6" so that the same side 8 is dried.
• the present invention enables the web 1A to be reversed from a first section Al to a second section Bl so that during passage of the web 1A through the first section Al, a first side 8A of the web 1A comes into physical contact with the drying rollers
• Figure 3 is an enlarged, fragmentary view of the transfer section shown in figure 2 to show how the web 1A is reversed. More particularly, with reference to figure
• the apparatus generally designated 10 for sequentially drying both sides 8A and 9 of a paper web 1A includes a first drying roller with the web extending around a portion of the circumference of the first drying roller
• a first felt 4A extends around a portion of the first drying roller 2A ⁇ such that the web 1A is sandwiched between the first felt 4A and the first drying roller 2A" for heating a first side 8A of the web 1A.
• a first suction roller 3A ⁇ ' i ⁇ disposed do-wnstrea relative to the first drying roller 2A".
• the first suction roller 3A"' has an axis of rotation which is disposed parallel and spaced relative to the rotational axis of the first drying roller 2A".
• the first felt 4A and the web 1A extend around a portion of the circumference of the first suction roller 3A" ' such that the first felt 4A is sandwiched between the web 1A and the first suction roller
• First guiding means 5A as shown in figure 2, guide the first felt 4A away from the first suction roller
• a second suction roller 7A is disposed adjacent to the first suction roller 3A"' , the second suction roller 7A having an axis of rotation parallel and spaced relative to the axis of rotation of the first suction roller 3A" ' .
• a second felt 4A' extends around the second suction roller
• a second drying roller 6A is disposed downstream relative to the second suction roller
• the first felt 4A is a continuous loop which extends in sinusoidal configuration past alternate drying and suction rollers 3A, 2A, 3A', 2A 1
• drying rollers physically contact the first side 8A of the web 1A and the second plurality of drying rollers 6A, 6A' and 6A" physically contact the second side 9 of the web 1A so that alternate sides of the web 1A are sequentially dried.
• the first guiding means includes a first guide roll 5A for guiding the first felt 4A and the second guiding means includes the second guide roll 12 for guiding the second felt 4A 1 .
• alternate sides 8A and 9-of the paper web 1A are sequentially dried by the following process steps:
• the first felt 4A is guided around a first guide roll 5A and a second felt 4A' is guided from a second guide roll 12 around a second suction roll 7A such that the first and second felts 4A and 4A' respectively define therebetween a web transfer section 14 so that the web 1A supported by the first felt 4A is guided into the web transfer section 14 with the web 1A being disposed between the first and second felts 4A and 4A' respectively.
• the web 1A emerging from the web transfer section 14 is drawn around the second suction roller 7A such that the second felt 4A' is disposed between the web 1A and the second suction roller 7A. 5. Thereafter, the joint run of the web 1A and second felt 4A* is directed around a second drying roller
• the present invention provides a simple means for positively transferring the web between successive groups of dryers in a BEL RUN configuration such that alternate sides of the web may be dried thereby providing a paper product having uniform surface characteristics, surface strength and smoothness, and no tendency to curl.
• the suction rollers are disposed below the drying rollers whereas in the second group of dryers, the suction rollers are disposed above the drying rollers.

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• Paper (AREA)
• Drying Of Solid Materials (AREA)

Priority Applications (9)

Applications Claiming Priority (2)

Publications (2)

Family

ID=16163349

Family Applications (1)

Country Status (16)

Cited By (14)

Families Citing this family (6)

Citations (2)

Family Cites Families (4)

• 1986
  • 1986-12-02 JP JP1986185019U patent/JPS6389996U/ja active Pending
• 1987
  • 1987-11-12 DE DE8888901398T patent/DE3775567D1/de not_active Expired - Lifetime
  • 1987-11-12 WO PCT/US1987/003087 patent/WO1988004206A2/en active Application Filing
  • 1987-11-12 DE DE198888901398T patent/DE334899T1/de active Pending
  • 1987-11-12 EP EP88901398A patent/EP0334899B2/en not_active Expired - Lifetime
  • 1987-11-12 DE DE8717870U patent/DE8717870U1/de not_active Expired - Lifetime
  • 1987-11-12 AU AU12439/88A patent/AU612349B2/en not_active Expired
  • 1987-11-12 AT AT88901398T patent/ATE70868T1/de not_active IP Right Cessation
  • 1987-11-12 BR BR8707946A patent/BR8707946A/pt not_active IP Right Cessation
  • 1987-11-12 KR KR1019880700915A patent/KR940005201B1/ko not_active IP Right Cessation
  • 1987-11-30 CA CA000553056A patent/CA1340582C/en not_active Expired - Fee Related
  • 1987-12-01 IN IN940/CAL/87A patent/IN168979B/en unknown
  • 1987-12-01 ZA ZA879009A patent/ZA879009B/xx unknown
  • 1987-12-01 PH PH36148A patent/PH30381A/en unknown
  • 1987-12-02 CN CN87107232A patent/CN1013598B/zh not_active Expired
  • 1987-12-02 PL PL1987269182A patent/PL158253B1/pl unknown
  • 1987-12-21 AR AR87309466A patent/AR246571A1/es active
• 1989
  • 1989-06-01 FI FI892657A patent/FI892657A0/fi not_active Application Discontinuation
• 1996
  • 1996-01-25 FI FI960348A patent/FI960348A/fi not_active Application Discontinuation

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