US 3292274 A
Description (OCR text may contain errors)
E. SETH Dec. 20, 1966 ARRANGEMENT IN A DRYER OR A SIMILAR TREATMENT PLANT Filed March 18, 1,964
iNVENTORZ SETH R A W E ATTYS.
United States Patent 3,292,274 ARRANGEMENT IN A DRYER OR A SIMILAR TREATMENT PLANT Einar Seth, J onkoping, Sweden, assignor to Aktiebolaget Svenska Flaktfabriken, Stockholm, Sweden Filed Mar. 18, 1964, Ser. No. 353,033 Claims priority, appplication Sweden, Mar. 19, 1963, 30,006/ 63 4 Claims. (Cl. 34-155) The present invention relates to improved apparatus for a dryer or a similar treatment plant for a webor sheet-like material having a plurality of perforated distributing boxes for supplying treating medium to the web. In the preferred embodiment, the distribution boxes are disposed longitudinally in the transport direction and arranged substantially perpendicularly with respect to the transport direction. In addition, one or more of the distributing boxes of the treatment plant is provided with one or more dampers in the blowing box for the correction of the dry-content profile of the web.
In conventional treatment plants, even if all precautions are taken to give an absolutely even distribution to the treatment medium supplied, the treated material may show an uneven dry-content profile due to an uneven dehydration in the wet section. As this results in a serious decrease in quality, it is important to create an equaliza tion of the moisture in the material measured perpendicularly with respect to the transport direction of the material.
A principal object of the invention is to provide apparatus which permits equalization of the moisture in the material being treated, which apparatus is characterized in that dampers are arranged to individually shut-off and partially shield the perforations through which the treating medium is supplied, by means of a plurality of manoeuvring means spread over the width of the dryer and arranged to be individual. According to a suitable emodiment, the manoeuvring means comprises an eccentric device mounted on a rotatable, for instance tubelike, shaft extending throughout the distributing box, the eccentric actuating a U-shaped loop circumscribing the damper. The loop, directly or by means of a plate spring secured to it and in contact with a part of the damper, presses the damper air-tightly against the perforated surface of the distributing box.
Other objects and a fuller understanding of the invention may be had by referring to the following description and claims taken in conjunction with the accompanyingdrawing showing a fragmentary sectional view of a single distributing box equipped with a shielding device constructed in accordance with the present invention.
In the drawing 1 designates a distributing box for the supply of drying medium to a web (not shown) to be treated by the medium, which web is intended to be advanced in a direction perpendicular to the longitudinal axis of the distributing box i.e., as shown by the arrow. The top wall In of the distributing box is provided with a plurality of evenly distributed perforations 2 over which the web travels. To make possible shielding of selected parts of the box and thus certain numbers of the perforations, the distributing box is, in accordance with the invention, provided with a damper means, which in the present instance comprises a one piece band 3 of steel or other resilient material running transversely and lengthwise of the box and having an accompanying maneuvering means for selectively closing off portions of the perforations.
In the embodiment shown the maneuvering means comprises a plurality of eccentrics 4a, 4b and so on dependent upon the length of the distribution box, each mounted on an axle 5 traversing the distributing box. The eccentric actuates a U-shaped loop 6, which eccentric presses, in the present instance, against a spring plate 7 which moves the resilient band air-tightly against the perforated surface 1a of the medium distributing box. For the guidance of this resilient band there is a plurality of transversely oriented guide shoes 8 in the distributing box. As illustrated, the spring plate 7 is secured at one end to the loop 6, underlying the band 3, and is loosely coupled for axial movement to the shoes 8. By providing one or more distributing boxes in the dryer, each box equipped with an arrangement according to the invention, the necessary adjustment or correction of the moisture content across the web may be made. In operation the adjustment is carried out by shutting-off i.e. shielding the perforations below the occurring dry-lanes by means of one or more of the above mentioned dampers, while the remaining portions of the perforations of the medium distributing box are open to let the (drying) medium be discharged freely at other zones of the transport plane. In such cases when a number of distributing boxes of the described kind are arranged closely above each other the axles 5 of the dampers may suitably be inter-connected to make possible an adjustment from one and the same point.
Although the invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example i and that numerous changes in the details of construction and the combination and arrangement of parts may be made without departing from the spirit and the scope of the invention as hereinafter claimed.
What is claimed is:
1. In a dryer for a web or sheet-like material comprising a plurality of distributing boxes having a perforated top wall for supplying treating medium, said boxes being disposed one after the other in the transport direction with their longitudinal axes substantially perpendicular with respect to the direction of travel of said web, at least one of the distributing boxes of the dryer having means for the correction of the dry-content profile of said web; said means comprising at least one damper means interiorly of said distributing box adjacent'the perforated top wall, said damper means comprising a resilient band of material extending longitudinally and transversely of said distribution box, and including at least one maneuvering means positioned interiorly of said box, underlying said band to raise and lower at least a portion of said resilient band and thereby shield selected portions of said perforated surface upon actuation by said maneuvering means.
2. Apparatus in accordance with claim 1 wherein said maneuvering means comprises an eccentric turnably mounted on a shaft extending externally of said distribution box, and a U-shaped loop in contact with said band and engageable with said eccentric so as to press said band air-tightly against the perforated surface of said distributing box.
3. Apparatus in accordance with claim 2 including a plurality of said maneuvering means separately engageable with said band whereby selective portions only of said b and press air-tightly against the perforated surface of said distributing box upon actuation of individual maneuvering means.
4. Apparatus in accordance with claim 3 including a plurality of guide shoes in said distributing box adjacent the underside of said perforated surface for supporting said band, and a spring plate secured to said loop at one end and loosely coupled to one of said guide shoes at the 5 References Cited by the Examiner UNITED STATES PATENTS 1,298,655 4/1919 Briner 34-114 1,939,578 12/1933 Sullivan 34160 X 3,222,800 12/1965 Siegel et al. 34233 X FREDERICK L. MATTESON, JR., Primary Examiner. C. R. REMKE, Assistant Examiner.