Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F3/00—Press section of machines for making continuous webs of paper
  • D21F3/02—Wet presses
  • D21F3/0209—Wet presses with extended press nip
  • D21F3/0218—Shoe presses
  • D21F3/0227—Belts or sleeves therefor
  • D21F3/0245—Means for fixing the sleeve to the roller end

Definitions

• This invention relates to a sealing apparatus for sealing a movable blanket relative to a first press membe of an extended nip press. More specifically, this in ⁇ vention relates to a sealing apparatus for sealing a movable blanket relative to a first press member of an extended nip press wherein the first press member is of the so-called "apple" configuration.
• an extended ni press includes a first and second cooperating press members which define therebetween an extended nip.
• the arrangement is such that as the paper web extends through such extended nip, the residence time of the paper web between the cooperating press members is increased rela ⁇ tive to the residence time of a more conventional nip defined by a pair of cooperating rolls.
• the increased residence time has a profound effect on the amount of water removed from the paper web, partially because the water removing pressure is exerted more gradually and for a longer period than is the case with a conventional nip defined by a roll couple.
• the present invention seeks to overcome the aforemen ⁇ tioned problem associated with such seepage of the lu ⁇ bricating oil and thereby provides a significant contri ⁇ bution to, and advancement over, the prior art proposals.
• Another object of the present invention is the provision of inflatable annular sealing means secured to rotatable heads disposed adjacent the first and second ends of the first press member so that when the seals are inflated, the blanket is sealed relative to the first press member.
• Another object of the present invention is the provision of a sealing apparatus in which when the seals are inflated, the blanket is permitted to rotate relative to, and around, the first press member.
• Another object of the present invention is the provision of a sealing apparatus in which when the seals are disposed in a deflated second position thereof, the blanket is permitted to be moved axially relative to the first press member for replacement of the blanket.
• Another object of the present invention is the provision of a sealing apparatus in which when the seals are disposed in an inflated first position thereof, the blanket is permitted to move axially relative to the first press member while maintaining a sealing engagement with the inner surface of the blanket.
• This invention relates to a sealing apparatus and a method for sealing a movable blanket which extends through an extended nip defined by first and second cooperating press members.
• the sealing apparatus seals the blanket relative to, and between, a first and second end of the first press member.
• the apparatus includes a first rotatable head disposed adjacent to the first end of the first press member. The first head is disposed coaxial relative to the first press member.
• a second rotatable head is disposed adjacent to the second end of the first press member with the second head being disposed coaxial relative to the first head and the first press member respectively.
• a first annular seal means is disposed between the blanket and the first head for sealing the blanket relative to the first head.
• a second annular seal means is disposed between the blanket and the second head for sealing the blanket relative to the second head.
• the arrangement is such that when the first and second seal means are in an inflated first position thereof, the blanket is permitted to rotate coaxially around the first press member.
• the blanket is movable axially relative to the seal means for replacing the blanket.
• the first and second heads are each of disc ⁇ shaped configuration and are rotatable relative to the first member.
• the first and second seals are fabricated from an elastomeric material and are of a hollow, toroidal configuration such that when the seals are inflated, a sealing member of each seal is urged radially outwardly relative to the respective head into sealing conformity with the inner surface of the movable blanket.
• a base portion of each seal is connected with a respective head so that when the seals are inflated, the blanket is supported by the seal members and enabled to rotate with the heads around the stationary first press member.
• any axial movement of the blanket relative to the first press member can be accommodated when the seals are inflated.
• the base portion defines a convex surface in a cross-machine direction and the first and second rotatable heads each define a concave rim surface in a cross-machine direction.
• the concave rim surface cooperates with the convex surface of the base portion for permitting axial mounting of the respective seal means onto the respective head.
• the first and second rotatable heads each further include a rim portion with the rim po ⁇ tion of each head defining a plurality of radial slots.
• a plurality of threaded fasteners are anchored within the base portion with the threaded fasteners having threaded portions extending radially inwards relative to the base portion. The arrangement is such that the inwardly extending threaded portions cooperate with the radial slots so that when the seal means is moved axially relative to the rim portion, the threaded portions are received within the radial slots.
• a plurality of internally-threaded members co ⁇ operate with the threaded portions for anchoring the base portion relative to the rim portion.
• the sealing member is movable to a compressed third position thereof when the respective seal means is inflated.
• the third position is attained during compression of the respective seal means when that portion of the respective seal means passes through the extended nip.
• the seal means defines, in an unstressed and unbiased disposition thereof, a cross-sectional configuration of the seal means when disposed in the second position thereof.
• This unstressed and unbiased second disposition of the seal means with the seal means being disposed between the first and third positions thereof, is such that during stressing of the seal means during use of the sealing apparatus, the life of the seal means is extended.
• the first and second seal means each further include a base portion for connecting the respective seal means to the respective rotatable head and a sealing portion disposed diametrically opposite to the base portion with the sealing portion defining a plain sealing surface disposed adjacent to an inner surface of the movable blanket.
• means are provided for connecting a compartment defined between the blanket, the first press member and the first and second seal means to a source of pressurized fluid.
• the source of pressurized fluid is preferably pressurized air, such that during use of the apparatus with the seal means disposed in the inflated first position thereof, the pressurized air within the compartment is above ambient atmospheric pressure.
• the pressurized air within the compart ⁇ ment is within the range 1-2 pounds per square inch and the seal means are each internally pressurized within the range 20-40 pounds per square inch in the first position thereof.
• the present invention also includes a method of sealing a blanket extending through an extended nip so that the blanket is sealed relative to the first press member.
• the method includes the steps of deflating the seals, moving the blanket axially relative to, and around, the first press member so that the blanket encircles and enwraps the first press member, then inflating the seals so that the seals are urged radially outwardly against the inner surface of the blanket for maintaining a seal between the blanket and the stationary first member when the blanket rotates relative to, and around, the station ⁇ ary first press member.
• Figure 1 is a side-elevational view of an extended nip press of the "apple” type showing a stationary "apple” shaped first press member and a cooperating rotatable second press member with an inflatable sealing apparatus disposed between the blanket and the first press member.
• Figure 2 is a sectional view taken on the line 2-2 of figure 1.
• Figure 3 is an enlarged fragmentary view taken on the line 3-3 of figure 2 showing the disposition of the first and second seals relative to the blanket and the first and second heads when the seals are inflated.
• Figure 4 shows one of the seals in the deflated second' position thereof.
• Figure 5 is an enlarged sectional view of one of the seals in an air inflated first position thereof, the seal being subjected to radial deflection by the blanket, and
• Figure 6 shows the seal of figure 5 in an inflated first position thereof with the blanket having been moved axially relative to the first press member while maintain ⁇ ing a sealing relationship between the blanket and the first press member.
• Figure 7 is a sectional view of an embodiment of the present invention showing one of the seal means with the base portion thereof defining a convex surface.
• Figure 8 is a sectional view of another alternative embodiment of the present invention showing one of the seal means viewed in a ciross-machine direction and showing an alternative means of anchoring the seal means to the rotatable head.
• Figure 9 is a sectional view of the seal means shown in figure 3 in the inflated first disposition thereof.
• Figure 10 is a sectional view of the seal means shown in figure 9 but with the seal means in the second deflated disposition thereof.
• Figure 11 is a sectional view of the seal means shown in figure 9 with the seal means disposed in the compressed third disposition thereof.
• Figure 12 is a sectional view of a further embodiment of the present invention showing an alternative seal means in which the sealing portion defines a plain surface;
• Figure 13 is a fragmentary sectional view of the seal means showing the compartment and the means for connecting the compartment to a source of pressurized air.
• FIG. 1 is a side-elevational view of a typical "apple" type extended nip press having a sealing apparatus according to the present invention.
• the apple type extended nip press is generally designated 10 and includes a first stationary apple-shaped press member 12 and a cooperating rotatable second press member 14.
• the first and second press members 12 and 14 respectively, define therebetween, an extended nip 16 for the passage there ⁇ through of a paper web W to be pressed.
• a felt F simul ⁇ taneously extends through the extended nip 16 such that as water is removed from the web W such water is taken up and absorbed by the felt F.
• the first press member 12 defines a concave surface 20 for the cooperating reception therein of the rotatable second press member 14.
• the blanket 18 moves substantially at the same speed as the felt F and web W during passage through the extended nip 16 so that there exists relative movement between the inner surface 22 of the blanket 18 and the concave surface 20 of the first stationary press member 12.
• This relative movement of the blanket 18 relative to the first press member 12 necessitates the provision of a lubricating medium between the inner surface 22 of the blanket 18 and the concave surface 20 of the first press member 12.
• the present invention includes a first rotatable head 30 disposed adjacent to the first end 32 of the first press member 12.
• the first head 30 is disposed coaxial relative to the first press member 12.
• a second rotatable head 34 is disposed adjacent to the second end 36 of the first press member 12 so that the second head 34 is disposed coaxial relative to the first head 30 and the first press member 12.
• a first annular seal means 38 is disposed between the blanket 18 and the first head 30 for sealing the blanket 18 relative to the first head 30.
• the blanket 18 is permitted to rotate coaxially around the first press member 12.
• the blanket 18 is movable axially relative to the seal means 38 and 40 for replacing the blanket 18.
• figure 2 shows the first and second rotatable heads 30 and 34 respectively as each defining a disc-shaped configuration with the first and second heads 30 and 34 respectively, each being rotatable relative to the stationary first press member 12.
• Figure 3 is an enlarged fragmentary sectional view of the first and second seal means 38 and 40 respectively.
• the seal means 38 and 40 are of an elastomeric material and are preferably fabricated from rubber.
• Each of the seal means 38 and 40 are of hollow, toroidal configuration as shown in figure 3.
• the first and second seal means 38 and 40 are able to be inflated or deflated by means of a flow control means generally designated 42 which is connected respectively to the first and second seal means 38 and 40 for controlling the inflation and deflation of the annular seal means 38 and 40.
• the first annular sealing means 38 includes a base portion 44 for connecting the seal means 38 to the rotatable head 30.
• a sealing member 46 is disposed diametrically opposite to the base portion 44 such that when the sealing means 38 is inflated, the sealing member 46 is urged into sealing conformity with the inner surface 22 of the movable blanket 18.
• the sealing member 46 defines a serrated surface 48 with the serrations extending in a machine direction such that as the sealing member 38 is urged against the inner surface 22, an effective seal is estab ⁇ lished thereby.
• the second sealing means 40 also includes a base portion 50 and a sealing member 52 with a corre ⁇ spondingly serrated surface 54 defined thereby.
• the seals 38 and 40 expand radially by a distance of two inches (5.08 centimeters) between the deflated and inflated positions of the seals. In effect, this means that if the serrated surface 48 of the sealing member 46 defines a circle having a diameter of fifty-six inches (142.24 centimeters) when inflated.
• Such movement of the serrated surfaces 48 and 54 between the deflated and inflated positions thereof is ample for allowing lateral removal of the blanket when the seals 38 and 40 are in the deflated position thereof whereas when the seals 38 and 40 are inflated, the serrated surfaces 48 and 54 move radially outwardly sufficient to establish an effective seal relative to the inner surface 22 of the blanket 18 for inhibiting any cross-machine directional seepage of lubricating oil that would otherwise cause contamination of the treated paper web.
• FIG. 7 is a sectional view showing an alternative embodiment of the present invention. Similar reference numerals are used throughout the detailed description to indicate similar elements of the various embodiments of the present invention however, such numerals include alphabetical suffixes added thereto.
• the sealing means 38a includes a sealing member 46a and a base portion 44a.
• the base portion 44a defines a convex surface 45 which cooperates with a concave surface 47 defined by the first rotatable head 30a. This arrangement facilitates mounting of the seal means 38a onto the head 30a.
• Figure 8 shows an alternative embodiment of the present invention in which a rim portion 49 of the first rotatable head 30b defines a plurality of radial slots 51,53 and 55.
• a plurality of threaded fasteners 57,58 and 59 are anchored within the base portion 44b such that -inwardly extending threaded portions 60,61 and 62 co ⁇ operate with the radial slots 51,53 and 55 respectively so that when the seal means 38b is moved axially relative to the rim portion 49, the threaded portions 60-62 are received within the radial slots 51,53 and 55 respective ⁇ ly.
• a plurality of internally-threaded members 63,64 and 65 cooperate with the threaded portions 60-62 for anchor ⁇ ing the base portion 44b relative to the rim portion 49.
• the sealing member 38 is movable between a first, second and third position thereof as shown in figures 9-11 respectively.
• This third, compressed position, as shown in figure 11 is attained during compression of the seal means 38 when the inflated seal means 38 passes through the extended nip 16.
• the seal means 38, 38a or 38b defines, in an unstressed and unbiased disposition thereof, a cross-sectional configura ⁇ tion substantially equivalent to the cross-sectional configuration of the seal means when disposed in the second position thereof, as shown in figure 10.
• This unstressed and unbiased disposition of the seal means is disposed between the first and third positions as shown in figures 9 and 11 respectively so that during stressing of the seal means during use of the sealing apparatus between the first and third positions as shown in figures 9 and
• a sealing portion 66 is provided with the sealing portion 66 being disposed diametrically opposite to the base portion 44c.
• the sealing portion 66 defines a sealing surface 68 which is disposed adjacent to the inner surface 22c of the movable blanket 18c.
• the sealing surface 68 is a plain surface.
• channel means 70 defined by the stationary first press member 12d connect a compartment 72 defined between the blanket 18d, the first press member 12d and the first and second seal means 38d and 40d to a source of pressurized fluid 74 such that during use of the apparatus, with the seal means 38d and 40d disposed in the inflated first or third disposition thereof, the pressure within the compartment 72 is above ambient atmospheric pressure.
• the pressurized fluid is air and the pressure within the compartment 72 is within the range 1-2 pounds per square inch and the pressure within the seal means 38d and 40d is 20-40 pounds per square inch when the seal means 38d and 40d are in the first or third position thereof.
• the flow control means 42 is operated in order to deflate the seals 38 and 40 so that the blanket 18 can be moved axially to encircle and enwrap the first press member 12.
• the flow control means 42 is operated to inflate the seals 38 and 40 such that the serrated surfaces 48 and 54 thereof move radially outwardly into sealing engagement with the inner surface 22 of the blanket 18 so that the blanket 18, seals 38 and 40 and heads 30 and 34 can, together, rotate around the stationary first press member 12.
• the seals 38 and 40 can compress and deform in conformity with the configuration of the extended nip while maintaining the required sealing relationship between the blanket 18 and first press member 12.
• Figure 4 shows seal means 38 in the deflated position. With the seal means 38 deflated, a clearance of approximately two inches (5.08 centimeters) is provided between the inner surface 22 of the blanket 18 and the sealing means 38 and this is ample to permit the sideways removal of the blanket 18.
• Figure 5 shows the seal 38 in an inflated position thereof with the seal 38 being subjected to radial de ⁇ flection by the blanket 18. Also any lateral deviation of the blanket 18 relative to the stationary first press member 12 when the seal 38 is inflated can be adequately accommodated by the sealing relationship established between the serrated surface 48 and the inner surface 22 of the blanket 18 as particularly shown in figure 6.
• each of the heads 30 to 34 is slightly less than the distance between the axis of the first press member 12 and the lowest point of the concave surface 20.
• the present invention provides a simple and low cost means for overcoming the problem of web contamination by oil sprayed from the press blanket.

Landscapes

• Paper (AREA)
• Sealing Devices (AREA)
• Seal Device For Vehicle (AREA)
• Heating, Cooling, Or Curing Plastics Or The Like In General (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=25447682

Family Applications (1)

Country Status (7)

Families Citing this family (2)

Family Cites Families (2)

• 1987
  • 1987-09-25 CA CA000547906A patent/CA1307156C/en not_active Expired - Lifetime
  • 1987-10-19 WO PCT/US1987/002728 patent/WO1988003192A1/en active IP Right Grant
  • 1987-10-19 BR BR8707859A patent/BR8707859A/pt not_active IP Right Cessation
  • 1987-10-19 JP JP50691387A patent/JPH02500455A/ja active Granted
  • 1987-10-19 EP EP19870907389 patent/EP0327581B1/de not_active Expired
  • 1987-10-19 AU AU81711/87A patent/AU605804B2/en not_active Ceased
  • 1987-10-19 DE DE8787907389T patent/DE3773942D1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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