Patents by Inventor Jukka Lehtinen

Jukka Lehtinen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5950329
    Abstract: The invention relates to a method of and an apparatus for drying a fiber web, whereby the fiber web (5) is dried in a cylinder drying unit (12) and in a band drier unit (11). The cylinder drying unit (12) and the band drier unit (11) are arranged one above the other. A considerable space saving is then achieved and the building costs remain rather moderate. Simultaneously, a remarkable addition to the drying capacity is achievable by moderate investments by means of existing apparatuses, for instance. (FIG.
    Type: Grant
    Filed: December 1, 1997
    Date of Patent: September 14, 1999
    Assignee: Valmet Corporation
    Inventors: Jukka Lehtinen, Elias Retulainen
  • Patent number: 5933978
    Abstract: The invention relates to a method of and an apparatus for drying a fiber web, whereby the fiber web is dried in a cylinder drying unit (12) and in a band drier unit (11). The fiber web (5) is led from the cylinder drying unit (12) to the band drier unit (11) in such a way that it is easy to determine a desired dry content for the fiber web (5) in the cylinder drying unit (12) when the fiber web (5) is transferred to the band drier unit (11).
    Type: Grant
    Filed: December 1, 1997
    Date of Patent: August 10, 1999
    Assignee: Valmet Corporation
    Inventors: Jukka Lehtinen, Elias Retulainen
  • Patent number: 5899002
    Abstract: The drying apparatus comprises two endless bands (1, 2) that are impermeable to air and that have a good thermal conductivity. A fibre web (5) runs between the bands (1, 2) with at least one felt or wire (3, 4). The metal band in contact with the fibre web (5) is heated with a pressure chamber (9) containing a pressure medium that is steam. Correspondingly, the metal band in contact with the felt or wire (3, 4) is cooled. The pressure chamber (9) is sealed against the first band (1) with a seal (9a). In association with the pressure chamber (9) there is a steam recovery chamber (18), where steam and condensate that escape from between the seal (9a) and the first band (1) can be recovered. The steam recovered from the steam recovery chamber (18) is supplied for further use with a means according to the arrangement.
    Type: Grant
    Filed: April 11, 1997
    Date of Patent: May 4, 1999
    Assignee: Valmet Corporation
    Inventors: Jukka Lehtinen, Jarmo Puumalainen, Paavo Rautakorpi
  • Patent number: 5778555
    Abstract: An apparatus for drying and smoothing a fibre web (5) between two tight bands (1, 2) that move in parallel and turn around turning rolls (6a, 6b, 7a, 7b), the first band (1) being heated with hot steam and the second band (2) being cooled with water, and the fibre web (5) being conducted through the drying zone that the bands (1, 2) define together with at least one felt or wire (3, 4) such that the fibre web (5) is in contact with the surface of the first, heated band (1) and that the felt or wire (3, 4) is between the fibre web (5) and the second, cooled band (2). In the invention, the fibre web (5) is smoothed such that the press means located in the vicinity of the first turning rolls (6a, 7a) in the travel direction of the fibre web (5) apply to it a pressure that is essentially higher than the pressure in the other parts of the drying zone.
    Type: Grant
    Filed: July 15, 1997
    Date of Patent: July 14, 1998
    Assignee: Valmet Corporation
    Inventors: Jukka Lehtinen, Taisto Juntunen, Paavo Rautakorpi
  • Patent number: 5722182
    Abstract: A method for drying a fibre web comprising passing the fibre web with at least one paper machine fabric between two bands which move in parallel. The bands have a good thermal conductivity and are impermeable to air. The fibre web and paper machine fabric are passed between the bands so that the fibre web is in contact with a first band to be heated and the paper machine fabric is in contact with a second band to be cooled. The method includes heating the first band with pressurized hot water, and cooling the band to be cooled with cooling water having substantially the same pressure and a lower temperature than the hot water.
    Type: Grant
    Filed: January 15, 1997
    Date of Patent: March 3, 1998
    Assignee: Valmet Corporation
    Inventors: Jukka Lehtinen, Jarmo Puumalainen
  • Patent number: 5706587
    Abstract: An apparatus for drying a fibre web, the apparatus comprising two endless bands that conduct heat well and are impermeable to air, which bands are arranged to run part of the way parallel with each other, the first band (1) being heated and the second band (2a) being cooled and the fibre web (3) being conducted together with at least one fabric between the bands (1, 2a) in such a way that the fibre web is in contact with the heated band (1) and the fabric is between the fibre web and the cooled band (2a). The invention comprises additionally a third band (2b) that conducts heat well and is impermeable to air, which band is located after the second band (2a) in the travel direction of the bands and forms together with the first band (1) a second drying zone.
    Type: Grant
    Filed: November 7, 1996
    Date of Patent: January 13, 1998
    Assignee: Valmet Corporation
    Inventors: Jukka Lehtinen, Paavo Rautakorpi, Jari Ilomaki
  • Patent number: 5604995
    Abstract: The invention relates to wire seals for use in a drying space of a Condebelt.RTM. drying apparatus described in Finnish Patent 54 514. In the apparatus, a material web to be dried passes in a substantially airless space between two metal bands (1, 7), or other similar bands or membranes of good thermal conductivity, together with drying wires. One of the metal bands is arranged to heat and the other is arranged to cool; the heating band (1) evaporates moisture contained in the web (2) to be dried, the moisture condensing on the surface of the cooling band (7), separated from the web to be dried by drying wires (3, 4). The drying space between the bands (1) and (7) of the Condebelt.RTM.
    Type: Grant
    Filed: May 2, 1994
    Date of Patent: February 25, 1997
    Assignee: Valmet-Tampella Oy
    Inventors: Jukka Lehtinen, Paavo Rautakorpi, Seppo Haavisto
  • Patent number: 5594997
    Abstract: A drying apparatus for drying a fibre web between two tight bands that move in parallel and turn around turning rolls, wherein a fibre web is taken between heating wires through a drying zone defined by the bands, and auxiliary wires are arranged between the heating wires and the bands. The heating wires are permeable to steam, whereby the steam evaporating from the fibre web passes through the heating wires and the auxiliary wires toward the cooled bands simultaneously from both sides.
    Type: Grant
    Filed: January 19, 1996
    Date of Patent: January 21, 1997
    Assignee: Valmet Corporation
    Inventor: Jukka Lehtinen
  • Patent number: 5566472
    Abstract: The invention relates to seals for use at band edges in a Condebelt.RTM. apparatus described in Finnish Patent 54 514. In the apparatus, a material web to be dried passes in a substantially airless space between two metal bands (1, 7) or other similar bands or membranes of good thermal conductivity together with drying wires. One of the metal bands is arranged to heat and the other is arranged to cool; the heating band (1) evaporates moisture contained in the web to be dried, the moisture condensing on the surface of the cooling band (7), separated from the web (2) to be dried by drying wires. The drying space between the bands of the Condebelt.RTM. apparatus is sealed up at the edges by seal profiles (10, 11) attached to the heating band (1) or the cooling band (7). It is also possible to use a number of seal profiles positioned against each other or side by side.
    Type: Grant
    Filed: May 2, 1994
    Date of Patent: October 22, 1996
    Assignee: Valmet-Tampella Oy
    Inventors: Jukka Lehtinen, Paavo Rautakorpi, Seppo Haavisto
  • Patent number: 5471765
    Abstract: An arrangement in a dryer for a fibre web for sealing bands (5a, 5b) that move between a chamber (3) containing pressurized vapor and a chamber (1) containing pressurized water and transport a web (7) and a felt (8) between them, and also for sealing the edges of the chambers (1, 3). The arrangement comprises a closed recovery chamber (16) into which the edges of the bands (5a, 5b) extend and in which the vapor escaping from the vapor chamber (3) from between the band (5a) and the seals (9, 10) and the water escaping from the water chamber (1) from between the band (5b) and the seals (12, 13) gather, whereby the vapor and water can be discharged from the recovery chamber (16) such that they are cannot escape into surrounding air.
    Type: Grant
    Filed: January 26, 1994
    Date of Patent: December 5, 1995
    Assignee: Valmet-Tampella Oy
    Inventors: Paavo Rautakorpi, Jari Ilomaki, Jukka Lehtinen
  • Patent number: 4958444
    Abstract: An apparatus for drying a fibre web (4), wherein the web (4) is dired in at least two successive drying zones between a heated band (1b, 1d) and a cooled band (1a, 1c) moving substantially in parallel with and at equal speed as the web (4), the bands being endless and air-tight and having good thermal conductivity. In order to shorten the apparatus and to save energy, it comprises several drying zones positioned on top of each other in a direction transverse to the surface of the web (4), whereby the web (4) moves in opposite directions in drying zones positioned immediately on top of each other. Further, the endless band (1b, 1c) positioned between two drying zones positioned on top of each other forms one of the drying elements in both drying zones, whereby the same cooling or heating means (8, 9) positioned within the band (1b, 1c) between the rolls (2b, 3b; 2c, 3c) can cool or heat the web sections positioned within the length of both drying zones.
    Type: Grant
    Filed: May 8, 1989
    Date of Patent: September 25, 1990
    Assignee: Oy Tampella AB
    Inventors: Paavo Rautakorpi, Jukka Lehtinen, Pekka Majaniemi
  • Patent number: 4932139
    Abstract: A method of and an apparatus for a drying fibre web (8) between two metal band (1, 4) moving in the same direction substantially in parallel with each other, whereby the fibre web (8) is led together with a felt (7) between the bands (1, 4), and the band (1) on the side of the web (8) is heated and the band (4) on the side of the felt (7) is cooled. In order to achieve a sufficient drying rate particularly when drying thick web grades while keeping the pressure exerted on the web at a low level, condensing pipes (13a to 13b) for back-pressure steam are mounted on the surface of the band (1) to be heated on the side facing away from the web (8), and a heat transfer medium, such as heat transfer oil (11) or the like, is provided between the pipes (13a to 13b) and the band (1).
    Type: Grant
    Filed: June 20, 1989
    Date of Patent: June 12, 1990
    Assignee: Oy Tampella Oy
    Inventor: Jukka Lehtinen
  • Patent number: 4899461
    Abstract: A method for drying a fibre web such as a paper or paper board web, wherein air is first removed from the web and a dryer felt, whereafter they are led together between two parallel metal bands moving at the same speed as the web and the felt. For drying the web, the band on the side of the web is heated by means of a heating device before the band reaches the drying zone and, correspondingly, the band on the side of the dryer felt is cooled before the band reaches the drying zone and comes into contact with the dryer felt. In the method, for adjusting the mechanical Z compression exerted peripendicularly on the surface of the web, the temperature of the cooling band is adjusted so that the difference between the condensation pressure of the steam condensed on the surface of the band on the side of the dryer felt and the pressure acting on the outer surface of the bands is substantially equal to the desired mechanical Z compression.
    Type: Grant
    Filed: January 12, 1989
    Date of Patent: February 13, 1990
    Assignee: Oy Tampella AB
    Inventor: Jukka Lehtinen
  • Patent number: 4787641
    Abstract: An arrangement for sealing a chamber containing pressure medium against a movable band. The band is arranged to form one side of the chamber. The arrangement comprises a sealing framework which is fastened to a body part of the chamber by means of a resilient membrane. The sealing framework is further provided with a sealing means for providing a sealing effect between the movable band and the rest of the chamber. The sealing means is thereby arranged to be pressed against the band by the pressure effect of a load medium fed on one side of the resilient membrane. In order to obtain an effective and adaptable sealing effect, the means for providing the sealing effect is formed by at least two sealing elements arranged in parallel and between which a sealing liquid is provided.
    Type: Grant
    Filed: December 22, 1987
    Date of Patent: November 29, 1988
    Assignee: Oy Tampella AB
    Inventors: Paavo Rautakorpi, Pekka Majaniemi, Jukka Lehtinen
  • Patent number: 4622758
    Abstract: The invention relates to a method of and a device for drying a paper web or the like, in which method a web (8) and a wire or felt (9) supporting it are subjected to a deairing treatment. The wet web (8) and the wire or felt (9) thus deaired the thereafter passed between two displaceable airtight surfaces of high heat conducting properties, between which surfaces the web (8) is enclosed in the drying zone over the whole width thereof. The surface making contact with the web (8) is heated and the surface making contact with the wire or felt (9) is cooled by liquid in order to condense the water evaporated from the web (8) into the wire or felt (9). The wire or felt (9) is separated from the dried web (8) after said surfaces and the water condensated is removed therefrom. In a drying process the surface making contact with the wire or felt (9) is formed by the outer surface of a cooled rotating metal cylinder (2).
    Type: Grant
    Filed: September 11, 1985
    Date of Patent: November 18, 1986
    Assignee: Oy Tampella Ab
    Inventors: Jukka Lehtinen, Olli-Pekka Sorma
  • Patent number: 4558960
    Abstract: The invention provides a radial friction bearing assembly, particularly for rotatably mounting the rolls of a paper or textile material processing machine, which will give a stable rotational movement without any vibrations and ensures that always an uninterrupted lubrication film is available, even at very low rotational speeds. A preferred embodiment of the bearing assembly comprises a stationary shaft member and an annular sleeve member rotatably mounted on the shaft member. The latter one comprises on its outer surface a plurality of equidistantially arranged longitudinal grooves which extend parallelly to the axis of the shaft member. A plurality of trapezoidally shaped recesses or pockets, having a substantially smaller depth than the longitudinal grooves, extend from and communicate with said grooves, the base edge of the trapezoid adjoining the leading edge of the longitudinal grooves.
    Type: Grant
    Filed: April 3, 1985
    Date of Patent: December 17, 1985
    Assignee: Arcomac S.A.
    Inventors: Jukka A. Lehtinen, Arvo K. Karhola, Walter H. Griner
  • Patent number: 4506456
    Abstract: A method for drying a porous web, according to which method the wet web is passed onto at least one drying felt, the web and the drying felt are subjected to an air removal treatment, and the web and the drying felt are passed between two surface elements which are impermeable to liquid and form an extended press zone in which the web is subjected to a pressing effect from both sides. Before the press zone the wet web is heated to a temperature of at least nearly 100.degree. C., and in the press zone the drying felt is kept at a temperature lower than the temperature of the wet web, so that a lower pressure is produced in the drying felt, and the high temperature of the water in the web causes an explosive evaporation and transfer of water from the web into the felt.
    Type: Grant
    Filed: March 16, 1983
    Date of Patent: March 26, 1985
    Assignee: Oy Tampella AB
    Inventor: Jukka Lehtinen
  • Patent number: 4506457
    Abstract: A method and an apparatus for drying a paper, or similar, web so that a wet web and a drying felt or wire are subjected to an air removal treatment, the web and the felt or wire freed of air are passed between moving surface elements having good heat conducting properties, said elements enclosing the web and the felt or wire along the whole width, the surface element contacting the web is heated in order to evaporate water contained in the web, and the surface element contacting the felt or wire is cooled in order to condense vapor emanating from the web into the felt or wire, and the felt or wire are separated from the dried web.
    Type: Grant
    Filed: March 16, 1983
    Date of Patent: March 26, 1985
    Assignee: OY Tampella AB
    Inventor: Jukka Lehtinen
  • Patent number: 4461095
    Abstract: A method of continuous drying of a paper or other porous web by passing the web (3) by means of a drying felt or wire (4) between two moving, air-impermeable surface elements (1, 8) having good heat conducting properties, which elements enclose the web along its whole width. The surface element (1) contacting the web is heated and the surface element (8) contacting the wire is cooled for evaporating water present in the web and condensing the evaporated water into the felt or wire. The temperature of the liquid used for cooling the surface element to be cooled is maintained above 100.degree. C. and the pressure at least at such a level as to prevent the liquid from boiling. Thus, the drying of the web can be carried out at an elevated temperature and under an elevated pressure in a continuous process at production conditions for improving the web characteristics.Preferably the cooling liquid is maintained at different temperatures and/or under different pressures at separate steps of the cooling process.
    Type: Grant
    Filed: February 2, 1982
    Date of Patent: July 24, 1984
    Assignee: Oy Tampella A.B.
    Inventor: Jukka A. Lehtinen
  • Patent number: 4173249
    Abstract: An extended nip press for a paper machine for removing water from a fiber web carried by a porous felt through a press zone in which the web is subjected to a pressure action. The press comprises press rolls forming at least two separate press nips and a sealing element positioned between the second rolls forming the press nips. The web, the felt and a band supporting the web and felt is passed through the press nips. A pressure medium chamber is limited by that part of the band which extends between the press nips, by the secondary rolls and the sealing element for subjecting the web to the pressure action. The press nips form rolling seals between the secondary rolls and the band.
    Type: Grant
    Filed: July 6, 1978
    Date of Patent: November 6, 1979
    Assignee: Oy Tampella AB
    Inventors: Seppo Holkko, Jukka Lehtinen, Pekka Majaniemi