Production Line for Producing Fiber Webs and a Cooler

Abstract

A cooler (144) providing gas blows and comprising at least one cooler module having at least one cooler module (41, 42, 43, 44) of the cooler (144) is curved to provide a gas turn module for turning run of the fiber web (W) from its main running direction 80-190°. The cooler (144) includes moisturizing at least one surface of the fiber web. Having a blowing zone (45, 46, 53) in which gas is blown toward a surface of the fiber web and that the cooler comprises at least one suction zone (51), in which the fiber web evaporated moisture is drawn away from the proximity of a surface of the fiber web. There are cooler modules on both sides of the fiber web. The cooler has a gas turn module located inside a curved fiber web run, which provides gas blows toward the curved fiber web during the run.

Claims

1. A fiber web cooler, for a fiber web, the fiber web defining a cross machine direction perpendicular to a travel direction of the web, and width in the cross machine direction, and a first and second opposed sides, and a first fiber web temperature before entering the fiber web cooler, comprising: a first cooler module, a second cooler module positioned opposite each other; a third cooler module positioned above or below and between the first cooler module and the second cooler module; wherein the third cooler module is positioned in fiber web receiving relation to the first cooler module, and the third cooler module is positioned in fiber web receiving relation to the third cooler module; therein the third cooler module forms a gas turn module having a curved non-contact surface extending through an angle of 80-190° and gas blows connected to a source of dry gas at a temperature less than first fiber web temperature, direct at the fiber web on the curved non-contact surface as the fiber web traverses the angle of 80-190°.

2. The fiber web cooler of claim 1 wherein the curved non-contact surface extending through an angle of 180°.

3. The fiber web cooler of claim 1 further comprising a fourth cooler module which is positioned between the first cooler module and second cooler module so that the fiber web is cooled on both side as the web transits the fiber web cooler.

4. The fiber web cooler of claim 1 wherein at least the first and second cooler modules have at least one moisturizing device having a moisturizing nozzle connected to a source of moisture and directed toward the fiber web to increase the moisture of the fiber web as it transits the first and second cooler modules; wherein the at least one moisturizing device has a suction zone connected to a source of suction between two rows of nozzle openings in the cross machine direction connected to the source of cooling gas at temperature which is less than the first fiber web temperature.

5. The fiber web cooler of claim 3 further comprising a moisturizing device connected to a source of moisture positioned to moisturize the at least one surface of the fiber web before the first cooler module.

6. The fiber web cooler of claim 5 further comprising two moisturizing devices connected to a source of moisture positioned to moisturize both surfaces of the surface of the fiber web before the first cooler module.

7. The fiber web cooler of claim 4 wherein a plurality of inner surface within each of the first and second cooler modules which define each of the suction zones and the inner surfaces of the moisturizing device which are hydrophilic are directed at least 15° downwardly with respect to a vertical direction defined by gravity.

8. The fiber web cooler of claim 4 wherein the source of dry gas has an adjustable temperature.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In the following paragraphs the invention is further explained in detail with reference to the accompanying drawings in which:

[0046] FIGS. 1-4 are schematically shown side elevational views of an advantageous example of a production line for producing fiber web according to the invention,

[0047] FIG. 5 is schematically shown as an advantageous example of a cooler providing gas blows, and

[0048] FIGS. 6A-6B are schematically shown side elevational views of advantageous examples of moisturizing devices.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] In the following disclosure and the accompanying drawings corresponding parts, part components, sections etc. are marked by the same reference signs unless otherwise mentioned. Further it is to be noted that in the figures some of the reference signs for details of parts, part components, sections have been omitted for clarity reasons as these details are well known to one skilled in the art.

[0050] In the schematic example of a production line for producing coated fiber webs, in particular coated board webs as shown in FIGS. 1-4 the production line for producing fiber webs comprises three head boxes 7, 8, 9 each for providing furnish for one fiber layer of the fiber web W and each followed by a forming unit 101, 102, 103 in a forming section 10 of the production line, in which forming section the fiber web W is formed and moisture is removed from the fiber web. In a press section 11 the fiber web W is pressed in press nips 111, 112. A drying section 12 of the production line comprises traditional drying in drying cylinder group(s) 121 of one-wire draw and/or in drying cylinder group(s) 122, 12N of twin-wire draw. The drying section 12 is followed by a size press 131 of a sizing section 13, which comprises a drying section 14 for the size, which drying section comprises a turning device 141, non-contact-dryer 142, and drying cylinder group 143 with twin-wire draw. After the drying section 14 for the size is provided a cooler 144. After the cooler 144 the fiber web is calendered in a calendering nip formed between two calender rolls in a calender 15 followed by drying by a non-contact dryer 152. There after the fiber web W is coated in coating section 16, 17, which provides coating for two coating layers by coaters 161, 171. Each coater 161, 171 is followed by a drying section comprising non-contact dryers 162, 172 and/or a drying cylinder group 163, 173. After the coating section an end calender 18 is located, in which the fiber web W is calendered in two calendering nips 181, 182 formed between calender rolls. At the end of the production line the fiber web W is reeled to a parent roll 192 having full width fiber web in a reel-up 19 by a reeling cylinder 191. The parent rolls 192 are transferred to an unwinder 201 of the slitter-winder 20. The unwound full width fiber web W is cut in longitudinal direction of the fiber web W i.e. slitted in a slitter 202 to partial fiber webs WN by slitter blades and the partial fiber webs WN are wound to partial fiber web rolls i.e. customer rolls in a winder 203.

[0051] These devices and sections can be constructed in various different designs and constructions known as such to one skilled in the art. Advantageously the head box is a two or a three layer head box 7, 8, 9, the press section comprises at least one roll press nip 111 and/or at least one shoe press nip 112, the drying section comprises at least one drying cylinder group 121 with one wire draw and/or at least one drying cylinder group 122, 12N with twin wire draw and the size press 131 is a bond sizer or a spray sizer or a film sizer.

[0052] The production line comprises at least one cooler 144 providing gas blows after the press section, at least one moisturizing device located before at least one cooler 144, at least one calender 15, a reel-up 19, a slitter-winder 20 and/or a sheet cutter. The cooler 144 comprises blower to direct dry, cool gas toward at least one surface of the fiber web W. Many different kinds of calenders 15 can be used as a pre-calender and/or as an intermediate and/or as an final calender, for example hard nip calenders, soft nip calenders, supercalenders, metal belt calenders, shoe calenders, long nip calenders, multi-nip calenders.

[0053] The production line can further comprise a Yankee cylinder and/or a belt arrangement, a size press 131 and an after drying section 14, 152 located after the Yankee cylinder and/or the belt arrangement and/or the size press and/or the calender 15 and a coating section 16, 17 for coating the fiber web by 1-4 layers of coating and non-contact dryers for drying the coating. The coating section 16, 17 comprises at least one coater 161, 171 of the following: a bond coater, an air brush coater, a sizer, a blade coater, a rod coater, a curtain coater, a spray coater, a cast coater.

[0054] Between the calender 15 of the production line and the last drying cylinder before it a non-contacting cooler for cooling the fiber web i.e. the cooler 144 providing cool gas is located and length of the fiber web run between last contact point of the fiber web on the last drying cylinder before the calender 15 and the first contact point of the fiber web on the first calender roll forming calendering nip of the calender 15 it is 7-20 m, advantageously 10-15 m.

[0055] As shown in the example of FIG. 5 the cooler 144 providing gas blows comprises cooler modules 41, 42, 43, 44, advantageously impingement drying modules 41, 42, 43, 44 and at least one impingement drying module 43 is curved providing a gas turn module 43 for turning run of the fiber web W from its main running direction, advantageously substantially horizontal direction, 80-190°. As shown in FIG. 5 cooling modules comprise blowing zones formed by nozzles 45, 46, which can have nozzle openings and/or slits in at least one row, in which dry, cool gas is blown towards at least one surface of the fiber web W and suction zones in between the nozzles 45, 46, in which suction zones from the fiber web W evaporated moisture is drawn away from the proximity of the surface of the fiber web W. As shown in FIG. 5 the cooler 144 providing gas blows can comprise cooler modules 41, 42, 44 on both sides of the fiber web W and a gas turn module 43 located inside the curved fiber web run, which gas turn module 43 having gas blows directed towards the curved fiber web during the run. The cooler 144 providing gas blows may comprise moisturizing devices 47, 48 for moisturizing at least one surface of the fiber web W. Advantageously in two on opposite sides of the fiber web located cooler modules 41, 42; 41; 44 the nozzles 45, 56 are located such that on the opposite side in respect of the nozzle a suction zone is located.

[0056] In FIGS. 6A-6B is shown an example of moisturizing devices 47, 48 for the production line comprising a suction zone 51 that extends to the substantial width of the fiber web W, which suction zone 51 is located advantageously between moisturizing nozzles 52 of the moisturizing device 47, 48 and outlet end of the moisturizing device 47, 48. The outlet end of the moisturizing device 47, 48 comprises a nozzle 53 for forming a sealing blow. As can be seen in FIGS. 6A-6B inner surfaces of the moisturizing device 47, 48 susceptible for moisture adherence are directed at least 15° downwards. At lower most point of the moisturizing device a drain connection 54 is located.

[0057] In this description and the following claims by fiber webs are meant for example paper and board webs.

[0058] A cooler module is a part of a device for cooling a fiber web which has blowing nozzle for cooling the web nozzle for reducing the moisture content of the fiber web surface so as to cool the fiber web below the plastic zone.

[0059] Above only some advantageous examples of the invention have been described to which examples the invention is not to be narrowly limited and many modifications and alterations are possible within the invention.