US3537955A - Pickup arrangement for papermaking machine - Google Patents

Pickup arrangement for papermaking machine Download PDF

Info

Publication number
US3537955A
US3537955A US680903A US3537955DA US3537955A US 3537955 A US3537955 A US 3537955A US 680903 A US680903 A US 680903A US 3537955D A US3537955D A US 3537955DA US 3537955 A US3537955 A US 3537955A
Authority
US
United States
Prior art keywords
felt
wire
web
pickup
water
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US680903A
Other languages
English (en)
Inventor
Leo A Huerta
Eugene S Skinner
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beloit Corp
Original Assignee
Beloit Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Beloit Corp filed Critical Beloit Corp
Application granted granted Critical
Publication of US3537955A publication Critical patent/US3537955A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
    • D21F2/00—Transferring continuous webs from wet ends to press sections

Definitions

  • ABSTRACT OF THE DISCLOSURE A pickup arrangement for removing a web from a forming surface wherein an endless felt is urged against the forming surface by means of a guide member having a curved surface in contact with said felt and a substantially flat surface diverging away from said felt thereby creating a pressure differential across the felt.
  • This invention relates to a felt pickup arrangement for removing a paper web from a traveling forming wire.
  • the sheet of paper formed on the Fuordrinier wire is transferred from the Fourdrinier wire to the press or dryer section of the papermaking machine by a felt urged into engagement with the sheet and wire by means of a roll, commonly termed a pickup roll.
  • the direction of the felt is changed to diverge from the wire with the sheet adhering to the felt.
  • the felt is normally trained about an upper felt roll downwardly to the pickup roll to be pressed into engagement with the sheet and wire by the pickup roll.
  • the pressure of the roll on the felt and the wire rapidly squeezes water out of the felt into the web or sheet and urges the sheet into the wire by the rapid flow of water from the felt through the sheet as it is squeezed by the wire.
  • This causes the sheet to become entangled into the wire and makes the subsequent washing of the sheet onto the felt more difficult as the felt expands when it leaves the wire.
  • the pressure on the felt decreases as it turns away from the wire, the expansion of the felt will cause a back flow of water from the underside of the wire which flow must be of sufficient velocity and volume to tear the base fibers of the sheet loose from the wire. This velocity of back flow is limited by the rate of felt expansion, as it leaves the wire.
  • P is the pressure between the wire and the web in pounds per square inch
  • T is the tension in the Fourdrinier wire in pounds per linear inch
  • R is the radius of the pickup roll in inches.
  • the centrifugal force F S /R wherein S is the speed of the web; R is the radius of the path through which the web travels,
  • the centrifugal force throws olf part of the water and tends to throw off the web retained by the felt with consequent damage to the web which is effectively transferred.
  • a principle object of the present invention is to remedy the foregoing problem in the transfer of paper from the wire to the press section of a papermaking machine by the provision of a vacuum generating means on the inside of the felt immediately following the point of transfer.
  • Another object of the present invention is to provide for a web transfer device which includes means for creating a pressure differential across the felt at a point on the felt immediately following the point of transfer of the web from the wire to the felt.
  • Yet another object of the present invention is to provide for a web transfer device which includes means for creating a pressure differential across the felt at a point starting immediately following the point of transfer of the Web from the wire to the felt and whereby this pressure differential is sustained for an extended period of time.
  • a still further object of the present invention is to improve upon the pickup of a newly formed web from the Fourdrinier wire by providing for a means for removing water from the inside of the pickup felt immediately following the pickup device.
  • FIG. 1 is a diagrammatic view of a felt pickup arrangement constructed in accordance with the principles of the present invention
  • FIG. la is a diagrammatic view of a modification of the arrangement shown in FIG. 1.
  • FIG. 2 is an enlarged view of a pickup device constructed in accordance with the principles of the present invention.
  • FIG. 3 is a diagrammatic illustration of a further embodiment of the present invention.
  • the discharge end or portion of a looped Fourdrinier wire 10 is shown as having a newly formed web W thereon and contacted by an endless pickup felt 12, picking the web from the wire by the backfiow of water onto the felt caused by expansion of the felt as the felt is urged against the wire and then gradually released therefrom.
  • the wire 10 is shown as being trained downwardly about a roll 13 in a downwardly inclined discharge run, to and about a roll 15 spaced a substantial distance in advance and below the roll 13 and about which the wire changes its direction for the return run of the wire.
  • the pickup felt 12 may be a conventional form of felt commonly used for pickup purposes and trained in an endless loop.
  • the felt 12 has a top run 14 which may be uniformly cleaned and moistened, and turns about an idle roll 16, disposed above and shown in FIG. 1 as directing the felt into an approaching run to the Fourdrinier wire 10. From the idler roll 16 the felt passes downwardly in an inclined direction and is pressed to engage and travel with the sheet W and wire 10 by a pickup shoe 17, contoured and positioned to provide a relatively intense contact pressure between the .felt and the wire and to provide for a small angle of divergence of the felt and web from the wire.
  • the pickup shoe 17 and its mounting and contour will hereinafter be more clearly described as this specification proceeds.
  • a uniform quantity of moisture may be supplied to the back sideof the felt by a water shower or other siutable device 18 to facilitate the sliding of the felt 12 over the shoe 17.
  • the press section 19 may be of any suitable design depending on the nature of the web W formed on the wire 10.
  • a scraper 35 is provided immediately following the shoe 17.
  • the scraper 35 removes the water extracted from the felt 12 by means of the diverging portion 21 of the shoe 17.
  • Attached to the scraper 35 is a saveall 36 designed to catch the'water removed by the scraper 35 and to convey the water away from the machine by gravity in a conventional manner.
  • FIG. 2 of the drawings we have illustrated the development of the shoe contour which will achieve the flow of water from the felt through the sheet and the wire in the quantity desired at the required location resulting in'a substantially instant termination of pressure so that the felt expansion can take place rapidly and the sheet can be effectively transferred to the felt and retained thereon.
  • the unit pressure exerted on the shoe by a felt or wire pulled around the shoe is a function of the tension in the felt or wire and the contour of the surface of the shoe.
  • the unit pressure is equal to the tension in the wire or felt divided by the radius or the mean radius of the contoured surface of the shoe.
  • the wire thus exerts the foregoing unit pressure on the moist felt as the felt and wire wrap the surface of the shoe.
  • This unit pressure causes water to flow from the felt through the sheet and wire to the underside of the wire in the pickup zone.
  • FIG. 2 the contour of the entrance face of the shoe is shown as being struck from a relatively small radius R1 which may be a radius varying from inch to approximately 10 inches depending on the particular felt and wire arrangement.
  • the entrance face 20 terminates and merges into a relatively straight surface 21.
  • the surface 21 commences at 22 and is tangent to the entrance surface 20.
  • the surface 21 diverges away from the felt 12 at an angle A which may vary from approximately /2" to 5".
  • the divergence between the felt 12 and the surface 21 creates an area Z of intense vacuum which 4 greatly assists in retaining the web W on the under side of the felt 12.
  • the shoe may be so constructed that the angle A is fixed, it is also possible to adjust the angle by rotating the shoe about the centre of the radius R1. Such an adjustment will permit optimum operating conditions for different quantities of water in the web and felt following the pickup point. It is understood that surface 21 may be slightly curved and that the curvature might be adjusted if the surface 21 were made of a flexible or thin material. If the pickup shoe is made of a rigid material, adjustment of angle A would be permitted by constructing enclosure 24 to incorporate suitable flexibility. While the angle A is preferably within the range of from /z to 5 larger angles may be advantageously used for special applications such as for example where a relatively low felt tension is used.
  • the surface 21 may have a small curvature, starting at the tangent point 22, in the form of a very large radius or of a variable radius often described as a foil.
  • the intensity of the flow of the water from the felt into the web and through the wire is relatively abrupt and occurs at high velocity whereas the reverse flow is much more gradual since the pressure is released more gradually. With the gradual return flow of water a substantial portion of the water will remain on the underside of the felt 1 2 which is the side to which the web W has been transferred. Due to this uneven distribution of the water in the felt and the effect of centrifugal force the web W has a tendency to drop off the felt 12.
  • the water thus transferred to the inside of the felt 12 may be effectively removed from the felt by means of a scraping device 23 located in scraping contact with respect to the felt and immediately following the vacuum zone Z.
  • a vacuum chamber V by means of an arcuately shaped wall portion 24 one end of which is attached to the pickup shoe at 25 and the other end of which is attached to the scraping device 23 at 26.
  • the vacuum chamber may also be designed so as to assist in the removal of Water scraped off the felt by the scraping device 23.
  • the pickup device to remove water from the web W which is adhering to the felt 18.
  • the felt 18 with the web W may be directed to transfer the web W directly to a drying cylinder or other drying means.
  • FIG. 3 illustrates another embodiment of the present invention in which the point of transfer is directly in contact with the forming wire trained around a cylinder.
  • the cylinder is constructed with an open surface created by drilling grooves or a grid pattern, with other portions of the forming wire surface being used for the formation of the web.
  • FIG. 3 a cylinder 30 of suitable construction is Wrapped around its circumference by the forming wire 31.
  • the web W could be formed on any portion of the forming wire sufficiently removed from the pickup device so as to not interfere with the pickup.
  • the felt enters the pickup shoe essentially as in FIG. 1 making contact with the Web W and causes the Web to adhere thereto.
  • said guide member having a curved peripheral surface in contact with said felt and a substantially fiat surface diverging away from said felt in the direction of travel of said felt at an acute angle of from /2 degree to five degrees for sufiicient length to create a substantial vacuum between said felt and said flat surface.
  • said adjustment means comprises means to vary the curvature of said surface.
  • said adjustment means comprises means to vary the angle of said surface with respect to the felt.

Landscapes

  • Paper (AREA)
US680903A 1967-11-06 1967-11-06 Pickup arrangement for papermaking machine Expired - Lifetime US3537955A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US68090367A 1967-11-06 1967-11-06

Publications (1)

Publication Number Publication Date
US3537955A true US3537955A (en) 1970-11-03

Family

ID=24732997

Family Applications (1)

Application Number Title Priority Date Filing Date
US680903A Expired - Lifetime US3537955A (en) 1967-11-06 1967-11-06 Pickup arrangement for papermaking machine

Country Status (8)

Country Link
US (1) US3537955A (enrdf_load_stackoverflow)
BE (1) BE716859A (enrdf_load_stackoverflow)
CH (1) CH494313A (enrdf_load_stackoverflow)
DE (1) DE1761934A1 (enrdf_load_stackoverflow)
FI (1) FI51975B (enrdf_load_stackoverflow)
FR (1) FR1569468A (enrdf_load_stackoverflow)
GB (1) GB1221695A (enrdf_load_stackoverflow)
NL (1) NL6807787A (enrdf_load_stackoverflow)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3992254A (en) * 1974-01-08 1976-11-16 Valmet Oy Structure for separating a web and wire in a paper machine
US5314585A (en) * 1993-05-10 1994-05-24 Champion International Corporation Low shear Uhle box
US5328569A (en) * 1992-06-26 1994-07-12 Beloit Technologies, Inc. Curved suction box apparatus in a papermaking machine press section
WO1996030590A1 (en) * 1995-03-24 1996-10-03 James River Corporation Of Virginia Method and apparatus for transferring a paper web from a wire to a transfering felt
US5725734A (en) * 1996-11-15 1998-03-10 Kimberly Clark Corporation Transfer system and process for making a stretchable fibrous web and article produced thereof
US5744007A (en) * 1996-09-03 1998-04-28 The Procter & Gamble Company Vacuum apparatus having textured web-facing surface for controlling the rate of application of vacuum pressure in a through air drying papermaking process
US5776311A (en) * 1996-09-03 1998-07-07 The Procter & Gamble Company Vacuum apparatus having transitional area for controlling the rate of application of vacuum in a through air drying papermaking process
AU710379B2 (en) * 1996-05-30 1999-09-16 Kimberly-Clark Worldwide, Inc. Method for improved rush transfer to produce high bulk without macrofolds
US6447641B1 (en) 1996-11-15 2002-09-10 Kimberly-Clark Worldwide, Inc. Transfer system and process for making a stretchable fibrous web and article produced thereof

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1530246A (en) * 1976-04-14 1978-10-25 Valmet Oy Method of and means for detaching and conducting a paper web in a paper-making machine

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3093535A (en) * 1958-07-14 1963-06-11 Stiftelsen Pappersbrukens Fors Method of dewatering pulp webs
US3207658A (en) * 1963-05-22 1965-09-21 Kimberly Clark Co Web transfer device for a papermaking machine
US3309263A (en) * 1964-12-03 1967-03-14 Kimberly Clark Co Web pickup and transfer for a papermaking machine
US3432385A (en) * 1965-12-15 1969-03-11 Huyck Corp Water extraction devices

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3093535A (en) * 1958-07-14 1963-06-11 Stiftelsen Pappersbrukens Fors Method of dewatering pulp webs
US3207658A (en) * 1963-05-22 1965-09-21 Kimberly Clark Co Web transfer device for a papermaking machine
US3309263A (en) * 1964-12-03 1967-03-14 Kimberly Clark Co Web pickup and transfer for a papermaking machine
US3432385A (en) * 1965-12-15 1969-03-11 Huyck Corp Water extraction devices

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3992254A (en) * 1974-01-08 1976-11-16 Valmet Oy Structure for separating a web and wire in a paper machine
US5328569A (en) * 1992-06-26 1994-07-12 Beloit Technologies, Inc. Curved suction box apparatus in a papermaking machine press section
US5314585A (en) * 1993-05-10 1994-05-24 Champion International Corporation Low shear Uhle box
WO1996030590A1 (en) * 1995-03-24 1996-10-03 James River Corporation Of Virginia Method and apparatus for transferring a paper web from a wire to a transfering felt
US5609728A (en) * 1995-03-24 1997-03-11 James River Corporation Of Virginia Method and apparatus for transferring a web from a forming wire to a transferring felt in a paper making machine
AU710379B2 (en) * 1996-05-30 1999-09-16 Kimberly-Clark Worldwide, Inc. Method for improved rush transfer to produce high bulk without macrofolds
US5744007A (en) * 1996-09-03 1998-04-28 The Procter & Gamble Company Vacuum apparatus having textured web-facing surface for controlling the rate of application of vacuum pressure in a through air drying papermaking process
US5776311A (en) * 1996-09-03 1998-07-07 The Procter & Gamble Company Vacuum apparatus having transitional area for controlling the rate of application of vacuum in a through air drying papermaking process
US5725734A (en) * 1996-11-15 1998-03-10 Kimberly Clark Corporation Transfer system and process for making a stretchable fibrous web and article produced thereof
US6447641B1 (en) 1996-11-15 2002-09-10 Kimberly-Clark Worldwide, Inc. Transfer system and process for making a stretchable fibrous web and article produced thereof

Also Published As

Publication number Publication date
BE716859A (enrdf_load_stackoverflow) 1968-12-02
FR1569468A (enrdf_load_stackoverflow) 1969-05-30
GB1221695A (en) 1971-02-03
DE1761934A1 (de) 1971-08-05
NL6807787A (enrdf_load_stackoverflow) 1969-05-08
CH494313A (de) 1970-07-31
FI51975B (enrdf_load_stackoverflow) 1977-01-31

Similar Documents

Publication Publication Date Title
US3224928A (en) Papermaking machine using a moving felt through a pressure forming slice and the same felt throughout the machine
US6231723B1 (en) Papermaking machine for forming tissue employing an air press
US3537954A (en) Papermaking machine
US3726758A (en) Twin-wire web forming system with dewatering by centrifugal forces
US3034180A (en) Manufacture of cellulosic products
US3537955A (en) Pickup arrangement for papermaking machine
US3565757A (en) Apparatus for forming and dewatering a fibrous web
US2959222A (en) Pickup and press section
US4100018A (en) Method and apparatus for forming a fibrous web
SE8800553L (sv) Blaslada for torkpartiet av en snabbgaende pappersmaskin
US3093535A (en) Method of dewatering pulp webs
US3298904A (en) Belt cleaning apparatus for a papermaking machine
ES465784A1 (es) Un metodo con su aparato correspondiente para la formacion en continuo de una lamina fibrosa.
US3150037A (en) Papermaking machine utilizing centrifugal dewatering
US3595745A (en) Web pick-up
US3441476A (en) Paper web transfer device utilizing suction box
US5501775A (en) Wet press for a paper making machine
US3470063A (en) Papermaking machine
US3826713A (en) Paper machine press section and method for using same
US3023805A (en) Transfer press
US2672078A (en) Suction press assembly
US3215592A (en) Paper press arrangement with automatic control of press felt moisture content
US4081320A (en) Method and apparatus for separating a fibrous web from a foraminous belt
US3543834A (en) Multi-layer centrifugal web former
US2744453A (en) Reverse press assembly