Abstract:
A cellulose pulp drying box for drying a web (18) of cellulose pulp comprises blow boxes (26, 32, 126) that are operative for blowing gas towards the web (18) of cellulose pulp for drying the pulp. At least 10% of the total number of blow boxes (26, 32,126) of the drying box (1) are provided, in their respective face (44, 54, 144) facing the web (18) during use of the drying box (1), with blow openings (60) having a characteristic measure of 1.5 to 5. mm through which blow openings (60) gas is blown towards the web (18) during use of the drying box (1). Each blow opening (60) is defined by an outlet opening (68) facing the web (18) during use of the drying box (1), an inlet opening (70) facing the interior of the blow box (26, 32, 126), and a lateral face (66) arranged between the outlet opening (68) and the inlet opening (70). At least a portion of the lateral face (66) of the respective blow opening (60) is provided with a shaped contour (62) for the purpose of sound attenuation.
Abstract:
A cellulose pulp drying box for drying a web (18) of cellulose pulp comprises blow boxes (26) that are operative for blowing gas towards the web (18) of cellulose pulp for drying the pulp. At least10 % of the total number of blow boxes (26) of the drying box are provided, in their respective face(44), with openings (48) having a characteristic measure of 1.8 to 3. mm and constituting at least 20% of the total degree of perforation of the face (44) of the respective blow box (26).
Abstract:
An arrangement for drying a web (18) of cellulose pulp comprises a drying box (1) which comprises blow boxes (26, 32) that are operative for blowing air towards the web (18) of cellulose pulp for drying the pulp in accordance with the airborne web principle. The drying box (1) comprises a first drying zone (4), which comprises first lower blow boxes (26) arranged to bear the web (18), and a second drying zone (6), which comprises second lower blow boxes (32) arranged to bear the web (18), with the first lower blow boxes (26) being different from the second lower blow boxes (32).
Abstract:
Bei einem Verfahren und einer Vorrichtung (10) zum Trocknen und Vorkondensieren von Imprägnaten (14), welche aus mit Kunstharz getränktem, folienartigem Bahnmaterial gebildet sind, wird das Imprägnat (14) mit Mikrowellen bestrahlt. Auf diese Weise können Imprägnate (14) erhalten werden, die sich, obgleich das Imprägnierharz Melaminharz-frei ist, zum Verpressen mit einem aus Holzwerkstoff gebildeten Grundkörper eignen.
Abstract:
The present invention concerns a convective system for a dryer installation for a passing web, more particularly paper. The convective system 7 is an assembly of an exterior casing 13 for suction of combustion products with opening 14 towards the web, with a first 15 and second 16 suction ducts sucking the combustion products into the convective system 7. The combustion products coming from the first suction duct 15 are guided through the exterior casing 13 to a mixing and blowing device 17. Cold air 18 is mixed in this mixing and blowing device 17 with the combustion products 19, resulting in a gas mixture with lower temperature 20. The convective system 7 also has an internal casing 21 inside the external casing 13. This internal casing 21 has at least one opening towards the web 22 and has also openings 34 allowing gas flow from the mixing device 17 to the internal casing 21 of said gas mixture 20. Under the internal casing 21, there is also a blowing duct 23. The second suction duct 16 is also arranged under this internal casing 21 thereby extracting a second flow of combustion products 24 into the internal casing 21. This second flow 24 of combustion products is then mixed with the gas mixture 20 coming from the mixing device 17, resulting in a mixture of gasses 25 with a temperature that is higher than the first gas mixture 20 and higher than e.g. 350 °C or 370 °C, more preferably 390 °C or 410 °C, even more preferably 420 °C, 450 °C or 500 °C. These hot gasses 25 are then blown to the drying web by the blowing duct 23 of the internal casing 21.
Abstract:
A device for guiding a metal strip (1) on a gas cushion with blast boxes (4), arranged in a row at a separation from each other, in the longitudinal direction (3) of the strip. The nozzle fields (5) of the above, which extend across the longitudinal strip direction (3), comprise hole jets (6) arranged over the field surface and slit jets (8) arranged along the edges (7) running transverse to the longitudinal strip direction (3). According to the invention, in order to achieve advantageous construction conditions, the slit jets (8) along the edges (7) comprise several jet slits (9) arranged in a series of rows, one behind the other, parallel to the edge, which, starting from the mid-point (10) of an edge, are directed inwards, relative to the edge (7).
Abstract:
A combination infrared/air convection dryer or oven for travelling webs. A shutter assembly (40) is provided between the infrared radiation source (17) and the moving web in order to selectively expose the web to infrared radiation, and to create a sealed air chamber (19) when in the closed position. Enhanced drying of the web and/or a coating on the web at high speed is achieved without a concomitant increase in dryer length. When the drying atmosphere has a high concentration of solvent, exposure of that atmosphere to the heating elements, which can cause explosions, is eliminated by actuation of the shutters. In a preferred embodiment of the invention, air bars are used to floatingly support the moving web to avoid contact of the web with dryer elements.
Abstract:
Air flotation dryer (10) for travelling web (W) includes a housing (11) having a web inlet (12) and a web outlet (13), a plurality of elongated air nozzles arranged transversely to the direction of movement of the web (W) and located on opposite sides. Thereof, the nozzles being secured directly to, supported by and in air-receiving communication with longitudinally extending supply air ducts. A fan communicates with the supply air ducts to supply air to the nozzles. A draw-through style burner fires into the dryer enclosure and the proper amount of air flow to be heated by the burner is regulated such as by a return air screen (50) having a predetermined or variable open area, resulting in a simpler design and a lower pressure drop than in the conventional ducted design where the recirculation air is first collected in a duct and is then heated and sent to the supply fan inlet.
Abstract:
Die Erfindung betrifft eine Vorrichtung zur Beaufschlagung einer Materialbahn (5) mit einem Gasstrom, insbesondere mit einem Trocknungsgasstrom zum Trocknen der Materialbahn (5), umfassend eine Transporteinrichtung (6), die dazu konfiguriert ist, die Materialbahn (5) entlang einer Transportrichtung (W) zu transportieren, sowie eine Strömungseinrichtung (1), die dazu konfiguriert ist, während des Transports der Materialbahn (5) einem oder mehreren Gasaustrittskörpern (2) jeweils eine Gasströmung zuzuführen und über den oder die Gasaustrittskörper (2) auf eine Oberfläche der Materialbahn (5) zu richten, um einen Wärmeaustausch zwischen der Gasströmung und der Materialbahn (5) zu bewirken. Ein jeweiliger Gasaustrittskörper (2) hat eine als Oberfläche ausgestaltete Gasaustrittsfläche (17) zum Austritt eines ersten Teilstroms (T1) der zugeführten Gasströmung und einen oder mehrere Gasaustrittsschlitze (18) zum Austritt eines zweiten Teilstroms (T2) der zugeführten Gasströmung. Die Strömungseinrichtung (1) ist derart ausgestaltet, dass sie in einem vorgegebenen Betriebsmodus als ersten Teilstrom (T1) bei dessen Austritt aus der Gasaustrittsfläche (17) eine laminare Strömung und als zweiten Teilstrom (T2) bei dessen Austritt aus dem oder den Gasaustrittsschlitzen (18) eine turbulente Strömung erzeugt.
Abstract:
Ein bekanntes Verfahren zum mindestens teilweisen Trocknen eines Substrats umfasst die folgenden Verfahrensschritte: (a) Erzeugung einer auf das Substrat gerichteten Zuluftströmung, die eine Zuluftströmungsrichtung aufweist, die eine Richtungs-Komponente in Transportrichtung oder in Gegenrichtung dazu hat und (b) Erzeugen einer vom Substrat wegführenden Abluftströmung. Um davon ausgehend ein Trocknungsverfahren anzugeben, das reproduzierbar und effektivist und insbesondere hinsichtlich Homogenität und Schnelligkeit der Trocknung des Substrats zu einem verbesserten Ergebnis führt, wird vorgeschlagen, dass die Abluftströmung in mehrere Teilströme aufgeteilt wird, indem jeder der Teilströme einem individuellen Ansaugkanal zugeführt wird, und dass im Fall einer Zuluftströmung mit einer Richtungs-Komponente in Richtung der Fortbewegung des Substrats die Zuluftströmung der Abluftströmung räumlich vorgeordnet ist, und im Fall einer Zuluftströmung mit einer Richtungs-Komponente in Gegenrichtung der Fortbewegung des Substrates die Zuluftströmung der Abluftströmung räumlich nachgeordnet ist.