Abstract:
A roll for calendars or super-calendars has a tubular rotatable roll shell (20) and a stationary core (30) extending through the roll shell. The space (31) between the roll shell and the core is divided by means of several peripheral seals (32) into numerous annular chambers (31a, 31b . . . ). A flow of fluid is guided through each of the annular chambers. The fluid temperature in each annular chamber is independently controllable. Consequently the roll shell (20) can be heated by the fluid to different degrees along the axis thereof to control its external diameter along each zone. The core (30) is only supported at its ends. The peripheral seals (32) are sized to have free play in a direction transverse to the roll axis and are constructed as endless, metallic rings. The external diameter of the rings is a trifle smaller than the internal diameter of the roll shell (20).
Abstract:
A press roll in a paper making machine comprises a non-perforated inner frame onto which an elastic layered structure is applied, the layered structure including an inner layer having a volume of which a substantial portion is constituted by cavities and an outer layer adapted to act against the inner surface of a looped press felt which passes through the press nip, the outer layer having passages formed therethrough which communicate with the cavities of the inner layer. During operation, the cavities are compressed together and thereby widen or extend the nip zone and, additionally, the cavities act as suction devices to produce a negative pressure in the nip zone following the centerline thereof. A press is disclosed which is formed by the press roll described above and a counter-roll which is provided with an elastic coating and a hollow face. A pair of press felts pass through the nip zone formed by these rolls between which the web to be dewatered is passed.
Abstract:
Destruction of the bond of urethane roll covers to metal paper machine rolls is eliminated by venting the interface of the urethane and the metal to the atmosphere. Venting of the interface can be accomplished by drilling small holes through the roll periphery, by applying an adhesive substrate to the roll with grooves exposed to the atmosphere, by providing porous wicks between the roll and cover or by grooving the periphery of the roll to provide channels exposed to the atmosphere.
Abstract:
A band press for a fiber web contains a cylinder having a solid surface over which there is guided the fiber web, for instance a paper web, which experiences a pressing or squeezing action in conjunction with a felt or wire and a press band which is impervious for a pressurized fluid medium. To accomplish the pressing or contact action there is provided a press housing containing a plurality of pressure chambers or spaces for pressurized fluid medium and with such pressure chambers operating at different pressures. The paper web is guided in a manner such that it bears upon the surface of the cylinder. The press housing is provided at the location where there outbound or depart the bands with a sharp departure or runnoff edge by means of which the bands are separated from the paper web which continues to remain at the cylinder.
Abstract:
A press section in a paper machine includes a first double felted press nip defined by first and second rolls through which first upper and second lower felt fabrics pass and at least two single felted press nips defined with a plain surface roll, the first felt fabric passing through a first one of the single felted press nips. The press section includes only non-suction rolls, the first and second rolls defining the first double felted press nip each having a solid shell and recessed surface. The first felt fabric supports the web leaving the wire section and is guided over a first sector of the first recessed surface roll wherein the direction thereof is changed so as to be directed generally upwardly prior to the first double felted press nip. The second lower felt fabric which passes through the first double felted press nip is guided over a second sector of the first recessed surface roll which comprises at least a substantial portion of the first sector thereof to provide external support for the web. The second felt fabric is separated from the web substantially immediately after the first double felted press nip whereupon the first felt fabric and web supported thereby is conducted to and passes through the first single felted press nip, the web then detaching from the first felt fabric and adhering to the surface of the plain surface roll for subsequent passage through the second single felted press nip.
Abstract:
A press roller, with adjustable bending characteristics, has a hollow roller shell which rotates around a fixed yoke. The shell is supported at each end by a self-aligning bearing. The press roller forms a pressure nip with a counter roller. Along this pressure nip, there is a semi-circular main pressure chamber arranged between the yoke and the roller shell, the length of which is equal to the length of the pressure nip. Adjoining this main pressure chamber there are provided at each end of the roller shell, a respective semi-circular additional pressure chamber. With a view to the bending characteristics of the yoke in the operation of the press roller, the axial and circumferential seals defining each additional pressure chamber are arranged on a respective annular shaped seal support. The latter support is supported by studs so that it may tilt on the yoke and shift axially with respect to the yoke.
Abstract:
A polyurethane rubber covered roll comprises a metallic roll core, a reinforcing layer adhering to the outer surface of the roll core, and formed by a nonwoven fabric impregnated with a mixture of a thermosetting resin and a fine inorganic powder, and a layer of polyurethane rubber united integrally with the outer surface of the reinforcing layer. The roll is useful when used, for example, in a paper machine.
Abstract:
A press section for extracting water from a continuous traveling web in which the web is sandwiched between a traveling belt and a drum. The belt is wrapped partially about the drum and a pressure shoe exerts pressure on the belt in the wrap area to press the web. The laterally outer ends of the drum are relieved to provide a reduced diameter portion in the areas extending laterally outwardly of the pressure shoe.
Abstract:
A roller, magnetically compensated and adjusted for deflection, has a non-rotating axle with ends having a load imposed thereat and a cylindrical shell rotatably supported by bearings on the axle. A magnetic core is formed in the axle and has in transverse section a plurality of pole shoes spaced from the shell by an air gap. A plurality of electromagnetic windings, each wound on the core at a corresponding one of the pole shoes, produce a magnetic force in a manner whereby the magnetic flux through the air gap between the pole shoes and the shell produces a compensating force field between the shell and the core.
Abstract:
An extended nip press for removing water from a traveling web in a paper machine including a press roll wth an elongate shoe having a concave surface facing the roll and forming an extended nip therebetween with an endless belt trained over the shoe for passing through the nip and first and second belts passing through the nip with the belt supported by a plurality of guide rolls or by an annular shell having continuous smooth outer surface extending from the outgoing side of the nip back to the oncoming side of the nip with a beam within the shell and a uniform fluid support for the shoe supported on the beam.