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
• • 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

Definitions

• the present invention relates to a press for extracting water from webs wherein at least one of the compression surfaces forming the nip is formed of an endless, flexible belt loaded by means of a supporting member.
• Structures of the aforementioned type are used in paper- making machines in order to form an extended nip and to render a higher water removal capacity than that of a conventional roll press.
• the press area of the belt is determined by the length of that part of the belt which is supported by the supporting member.
• the belt which is made of rubber is so flexible that it cannot press the web at an area outside the supporting member.
• the present invention is based on the fact that the belt, due to its stiffness, exerts pressure on a longer part of the web than the loaded part.
• Figure 1 is a schematic cross section of an extended nip press in accordance with the invention.
• Figure 2 shows the press nip of Fig. 1 in a larger scale.
• FIG. 3 is a schematic cross section of another embodiment of the invention.
• Figure 4 is a schematic cross section of a third embodiment of the invention.
• Figure 5 shows the press nip of Fig. 4 in a larger scale.
• Figure 6 is a cross section of a fourth embodiment of the invention.
• Figure 7 is a cross section of yet another embodiment of the invention.
• Figure 8 is a section as on the line A-A of Fig. 6.
• the press illustrated in Figs. 1 and 2 comprises two endless steel belts 1 and 2 between which a paper web 3 travels. Inside the belts 1 and 2 there are disposed rotatably mounted rolls 4 and 5 which act as loading and/or supporting members and which in a manner known per se cause the compression exerted on the web.
• the belts 1 and 2 cause the web 3 to be under compression in a press nip 6 the length L of which exceeds the width 1 of the contact area between the roIIs 4 and 5 and the belts 1 and 2. This is caused by the bending stiffness of the steel belts.
• Fig. 1 shows a press in which rolls 4 and 5 acting as loading and/or supporting members are disposed inside the belts 1 and 2 and supporting and loading rolls 8 and 9 are disposed outside the belts. In this way, an asymmetrical press nip has been provided for rolls 4 and 5.
• the press illustrated in Fig. 6 comprises a steel belt 1 and a press roll 14 between which the web 3 travels. Rolls 15 and 16 acting as supporting and loading members are disposed outside the belt.
• the belts may be grooved. Instead of rolls, supporting and loading members assembled of reels or wheels may be used. Instead of rolling elements connected by chain members, rolling elements moving in guiding grooves may be used.

Landscapes

• Paper (AREA)
• Press Drives And Press Lines (AREA)

Priority Applications (1)

Applications Claiming Priority (1)

Publications (1)

Family

ID=8516557

Family Applications (1)

Country Status (5)

Cited By (2)

Citations (2)

Family Cites Families (9)

• 1983
  • 1983-01-04 FI FI830014A patent/FI830014L/fi not_active Application Discontinuation
• 1984
  • 1984-01-02 DE DE19843490003 patent/DE3490003T1/de active Granted
  • 1984-01-02 WO PCT/FI1984/000001 patent/WO1984002726A1/en active Application Filing
  • 1984-01-02 GB GB08421467A patent/GB2142946B/en not_active Expired
  • 1984-08-30 SE SE8404335A patent/SE441937B/sv not_active IP Right Cessation

Patent Citations (2)

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