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US 5,566,473 AGranted
Processing roll apparatus and method for web drying
OwnerReijo K. Salmineninventor
Life of this patent
Estimating the term…
Abstract
A processing roll adapted to engage paper or the like to heat and/or shape the same. The roll has a cylindrical side wall and defines a interior condensing chamber for steam. The interior surface of the roll is formed with longitudinal grooves which slope away from the longitudinal axis toward a central location. The steam condensates in the chamber, collects in the grooves, and flows toward a center location where the condensate is siphoned out and removed from the chamber. Improved heat transfer is achieved, and greater uniformity of heat is accomplished at the outside surface.
Claims40
A method of processing material in heat transfer relationship, such as a sheet of paper, said method comprising:
- a. providing a roll structure mounted for rotation and defining an enclosed chamber to contain a condensable heat transfer medium, said roll structure comprising:
- i. a cylindrical side wall having a longitudinal center axis, an outside generally cylindrical contact surface to engage said material in heat transfer relationship and an inside generally cylindrical surface which is exposed to the heat exchange medium in said chamber in heat exchange relationship whereby the medium condenses on the inside surface and heat is conducted through the side wall to the outside surface, said inside generally cylindrical surface having a radial depth dimension at a radial surface distance from said longitudinal center axis;
- ii. first and second end walls at first and second ends of said side walls, respectively;
- b. providing the inside surface of the side wall with a plurality of longitudinally spaced circumferentially extending grooves, each of which as a substantial circumferentially aligned path component and which extends generally circumferentially along the inside surface of the side wall, said circumferentially extending grooves each having a radial circumferential groove distance to a bottom groove portion of each groove greater than said radial surface distance;
- c. providing the inside surface of the side wall with a plurality of circumferentially spaced, longitudinally aligned collecting grooves, spaced around the circumference of the inside surface of the side wall, each of said longitudinally aligned collecting grooves having a radial longitudinal groove distance to a bottom surface of each of said longitudinally aligned collecting grooves at least as great as said radial circumferential groove distance;
- d. providing said inside surface of said side wall having a circumferential collecting area having a radial collecting area distance sufficiently great to receive flow from said longitudinally aligned grooves;
- e. directing a condensable heat exchange medium into said chamber in heat exchange relationship with said inside surface, in a manner that the medium condenses on the inside surface to form condensate, said circumferential grooves, said longitudinal grooves, and said collecting area thus being arranged so that condensate forming on said inside surface is able to follow a flow path into said circumferential grooves, then into adjacent longitudinal collecting grooves and to said collecting area;
- f. collecting the condensate from the collecting area and directing the condensate from the chamber through a chamber outlet;
- g. placing said material in contact with the roll and rotating the roll.
6 more elements
A roll assembly to engage a material to be processed in heat transfer relationship, such as a sheet of paper, said roll assembly comprising:
- a. a roll structure mounted for rotation and defining an enclosed chamber to contain a condensable heat transfer medium, said roll structure comprising:
- i. a cylindrical side wall having a longitudinal center axis, an outside generally cylindrical contact surface to engage said material in heat transfer relationship and an inside generally cylindrical surface which is exposed to the heat exchange medium in said chamber in heat exchange relationship whereby the medium condenses on the inside surface and heat is conducted through the side wall to the outside surface, said inside generally cylindrical surface having a radial depth dimension at a radial surface distance from said longitudinal center axis;
- ii. first and second end walls at first and second ends of said side walls, respectively;
- b. the inside surface of the side wall being formed with a plurality of longitudinally spaced circumferentially extending grooves, each of which as a substantial circumferentially aligned path component and which extends generally circumferentially along the inside surface of the side wall, said circumferentially extending grooves each having a radial circumferential groove distance to a bottom groove portion of each groove greater than said radial surface distance;
- c. the inside surface of the side wall also being formed with a plurality of circumferentially spaced, longitudinally aligned collecting grooves, spaced around the circumference of the inside surface of the side wall, each of said longitudinally aligned collecting grooves having a radial longitudinal groove distance to a bottom surface of each of said longitudinally aligned collecting grooves at least as great as said radial circumferential groove distance;
- d. said inside surface of said side wall having a circumferential collecting area having a radial collecting area distance sufficiently great to receive flow from said longitudinally aligned grooves;
- e. said circumferential grooves, said longitudinal grooves;
- and said collecting area thus being arranged so that condensate forming on said inside surface is able to follow a flow path into said circumferential grooves, then into adjacent longitudinal collecting grooves and to said collecting area;
- f. condensate collecting means to collect the condensate from the collecting area;
- g. chamber inlet means through which said medium passes into said chamber and chamber outlet means through which condensate of said medium passes from said chamber.
7 more elements
A roll assembly to engage a material to be processed in heat transfer relationship, such as a sheet of paper, said roll assembly comprising:
- a. a roll structure mounted for rotation and defining an enclosed chamber to contain a condensable heat transfer medium, said roll structure comprising:
- i. a cylindrical side wall having an outside generally cylindrical contact surface to engage said material in heat transfer relationship and an inside generally cylindrical surface which is exposed to the heat exchange medium in said chamber in heat exchange relationship whereby the medium condenses on the inside surface and heat is conducted through the side wall to the outside surfaces;
- ii. first and second end walls at first and second ends of said side walls respectively;
- iii. said roll structure having a longitudinal center axis about which said roll structure rotates;
- b. the inside surface of the side wall being formed with a plurality of elongate grooves to receive condensate that condenses from said medium on said inner surface and provide flow paths for said condensate, said inside surface further providing a collecting location in communication with said grooves to receive the flow of the condensate along the flow paths;
- c. said flow paths each having an upstream flow path portion and a downstream flow path portion into which condensate flows from its related upstream flow path portion, said upstream flow path portions being closer to said longitudinal axis than said downstream flow paths portions, said downstream flow path portions leading into said collecting location at a plurality of downstream flow exit locations positioned at circumferentially spaced locations around said collecting location;
- d. condensate collecting means to collect the condensate from the collecting location;
- e. chamber inlet means through which said medium passes into said chamber and chamber outlet means through which condensate of said medium passes from said chamber.
5 more elements
A method of processing a material in heat transfer relationship, such as a sheet of paper, said method comprising:
- a. providing a roll structure mounted for rotation and defining an enclosed chamber, said roll structure comprising:
- i. a cylindrical side wall having an outside generally cylindrical contact surface inside general cylindrical surface;
- ii. first and second end walls at first and second ends of said side walls, respectively;
- iii. said roll structure having a longitudinal center axis about which said roll structure rotates;
- b. forming the inside surface of the side wall with a plurality of elongate grooves defining a plurality of flow paths, said flow paths each having an upstream flow path portion and a downstream flow path portion into which condensate flows from its related upstream flow path portion, said upstream flow path portions being closer to said longitudinal axis than said downstream flow path portions, said downstream flow path portions leading into said collection location at a plurality of downstream flow exit locations positioned past circumferentially spaced locations around said collecting location;
- c. directing a condensable heat exchange medium into said chamber in heat exchange relationship with said inside surface, in a manner that the medium condenses on the inside surface to form condensate and heat in conducted through the side wall to the outside surface, with the grooves receiving the condensate that condenses from said medium on said inner surface and directing the condensate in flow paths for said condensate to a collecting location in the chamber;
- d. collecting the condensate from the collecting location and directing the condensate from said chamber through chamber outlet;
- e. placing said material in contact with said roll, and rotating said roll as the medium is condensing in the chamber.
5 more elements
Dependencies are inferred from the claim text.