Abstract: A dryer uses conduits to carry a heating medium, such as steam, to heat the outer surface of the dryer. The volume of steam is successfully reduced to non-explosive levels and the shell need not be designed to prevent an explosion. Conduits may be formed through the shell itself or grooves may be formed on the inner surface of the shell, with the conduits retained within the grooves. Also, the conduits can be placed against the inside surface of the dryer and a material, such as zinc, can be filled in about the conduits. The material serves to both retain the conduits in place and thermally couple the conduits to the dryer to assure efficient heat transfer between the conduits and dryer. These modifications relieve the dryer from the Unfired Pressure Vessel classification to the classification of a piping assembly under ASA code regulations. This results in savings in operation safety, installation cost and operating costs due to the absence of costly inspections.
Type:
Grant
Filed:
November 9, 2009
Date of Patent:
March 6, 2012
Inventors:
Osvaldo Ricardo Haurie, Richard Kenneth Haurie
Abstract: A calender unit for producing and/or processing thin films, includes two rollers that are rotatably supported at two bearing points in a frame, which each include a hollow cylindrical roller body that forms the working roller circumference, the two roller circumferences forming a roller gap between themselves and at least the one roller is arranged so that it is able to be cooled using a heat exchange medium, the roller body of this roller being arranged as a hollow cylinder and the roller including a carrier which protrudes at one end from the roller body and is supported torsionally fixed on the frame as well as in the roller body to allow a rotation of same about the roller axis, the support of the crosshead taking place in the roller body between the two bearing points, as seen in the longitudinal direction, and device(s) being provided for reducing profile errors in the operation of the calender unit.
Abstract: A method for controlling the temperature of a heated roll in a calender is provided. The calender comprises at least one heated roll or thermoroll and at least one backing roll, between which is formed a nip through which the material web is conveyed. To the heated roll is supplied internal thermal power by internal heating means of the roll, and external thermal power by external heating means of the roll. Before changing the heated roll, internal thermal power is minimized within a specific period by control means provided in conjunction with the internal heating means; external thermal power is maximized within a specific period by control means provided in conjunction with the external heating means; and the surface temperature of and/or the thermal power released by the heated roll, which corresponds to the surface temperature and/or thermal power desired for the grade of the material web, is maintained within a specific period.
Abstract: A method and apparatus for producing calendered paper by an on-line manufacturing system comprising at least a paper machine and a multi-nip calender. The method comprises following steps: removing water from a formed paper web by pressing, drying the pressed paper web by at least one dryer, calendering the dried web by the multi-nip calender, measuring a cross-machine moisture profile or a variable relative thereto, and altering the moisture of the web so that the moisture profile of the web in the cross-direction is even when the web enters the first nip of the calender.
Type:
Grant
Filed:
November 13, 1998
Date of Patent:
July 24, 2001
Assignee:
Valmet Corporation
Inventors:
Harri Kuosa, Markku Kyytsönen, Juhani Partanen, Kari Sipi, Eero Suomi, Antti Heikkinen, Mikko Tani, Juha Lipponen, Mika Tammenoja, Kari Juppi
Abstract: A gradient calender including two calender rolls arranged to form a calendering nip, at least one of the rolls being a hard-faced calender roll which is heatable to a high temperature whereby a web is passed through the calendering nip for hot calendering the web. At least one of the calender rolls is arranged to be loaded toward the calendering nip by a respective variable-crown support roll so that an auxiliary nip between the support roll and the respective calender roll and the calendering nip are in a common nip plane. Deflection of the calendering nip and the calender rolls is substantially prevented by the effect of the load produced by hydraulic loading devices arranged in the support roll.