FI100413B - Steam box on a cardboard or paper machine - Google Patents

Description

100413 Steam box on a cardboard or paper machine Ängläda i kartong- eller pappersmaskin 5

The invention relates to a steam box comprising a steam chamber for blowing steam towards a web of paper or paperboard supported by a wire and a suction box arranged on the outlet side of the steam chamber for suction of steam mist.

A prior art steam box is used in connection with a paperboard or paper machine, through which hot steam is passed in connection with a paperboard or paper web to reduce the viscosity of the water in the web and thus to promote the drainage of water from the web. Steam boxes are used, for example, in the wire and press parts of a cardboard or paper machine for the above purpose. One problem with the steam box-15 sizes used with the wire sections is the blowing out of the non-condensable steam which wets the structures of the press section and even the entire paper machine room. This cloud of mist due to the blowing of steam causes, in the worst cases, even water to drip from the roof of the data center. Steam is blown out mainly from the trailing edge of the steam box and to some extent from the edges of the steam box. blow air; ·: This means that the entire capacity of the steam box cannot be used for efficient * * 20 ti dry matter lifting due to high mist formation and machine structures ·. ' . ' get too wet. One solution known from the prior art is to provide a suction on the discharge side of the steam box. However, this has not sufficiently eliminated the transfer of steam from the mist to the surrounding structures and the data center, so the steam box has had to be driven with insufficient power due to the steam being blown out. However, this has not been sufficient to prevent the spread and condensation of steam in the structures and the resulting dripping of water.

: J.i *. ‘· J ·’ A serious problem in the steam box of the wire section is that the steam box remains clean in the f 30 edge cutting area. In edge cutting, the web releases fiber and fillers that • '; stick and accumulate at the edges of the steam box and drip from it onto the web, causing! driveability problems and even line breaks on machines. This has led to the edge cutting having to be placed far away from the steam box, which, however, is not always possible due to lack of space, so it may be necessary to abandon the use of the steam box to increase capacity. Attempts have also been made to prevent contamination of the steam box due to edge cutting with an air version 5 in front of the steam box. However, this problem will continue to be exacerbated as machine speeds increase and more compact machines are sought.

It is an object of the invention to provide a steam box which does not have the problems described above.

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It is an object of the invention to provide a steam box in which the problems caused by steam blowing out are eliminated or at least minimized so that, if desired, the steam box can be used at full capacity.

It is an object of the invention to provide a steam box in which the fibers and fillers detached in the edge cut do not cause problems.

In order to achieve the above and later objects, the steam box according to the invention is mainly characterized in that the suction zone is also arranged on the sides of the steam chamber to extend to the edge areas of the track and that the steam box comprises edge cutting devices arranged on the side of the side-extending suction belt. to remove fibers and fillers from edge cutting in the affected area • · · to prevent fouling of the edges of the steam box.

25 in accordance with the invention, the steam box the trailing suction zone is arranged to extend ·. § also on the edges of the steam box and edge cutting is performed in the suction zone of the steam box: * · ’in the area and in the edge cutting the loose fiber and fillers are removed by vacuum to the same suction zone as the steam mist.

The steam box according to the invention is suitable for use both new and existing; ! in connection with existing machines.

3,100413

In the following, the invention will be described in more detail with reference to the figures of the accompanying drawing, the details of which, however, are not intended to be limited in any way.

Figure 1 is a schematic side view of a steam box according to the invention placed in connection with a suction roll of a wire section.

Figure 2 is a schematic side view of a steam box according to the invention placed in connection with a planar box.

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Figure 3 is a schematic top view of a steam box according to the invention.

Figure 1 schematically shows a steam box 10 arranged in connection with the suction roll 21 of the wire 20 15 of the wire section. The suction zone of the suction roll 21 is denoted by reference numeral 22. The steam box 10 comprises a steam chamber 11 from which steam is blown per track to increase capacity and a suction chamber 12 to suck out exuding steam to prevent the prevent it. Edge cutting. 20 devices for trimming the edges of the track are indicated by reference numeral 13.

• *! ’! Fig. 2 schematically shows another embodiment of the invention, in which the steam box 10 is arranged in connection with a planar box 24. As in the embodiment of Figure 1, the steam box 10 comprises a steam chamber 11, a suction zone 12 and 25 edge cutting devices 13.

• · • · j ':' Fig. 3 is a top view of a steam box according to the invention, • '' which may be either of the application examples according to Figs. Steam box-. · · ·. 10 comprises a steam chamber 11 and a steam chamber substantially located in the central region of the web. 30 edge cutting devices 13 arranged on each side of the mion 11, with the edges of the track! cut along section lines 14. The edge cutting can take place in the suction zones of the steam box or in the area of the steam chamber of the steam box when viewed in the transverse direction of the track. In connection with the steam box 11, a suction zone 12 is arranged on the discharge side, which also extends to the sides of the steam chamber as side zones 12A, thus providing a suction zone 12 which absorbs not only steam mist

The invention has been described above with reference only to some of its preferred examples, the details of which, however, are not intended to be limited in any way. Many variations and modifications are possible within the scope of the inventive idea defined by the following claims.

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Claims (3)

100413 A steam box comprising a steam chamber (11) for blowing steam towards a web of paper or board supported by a wire (20, 23) and a steam box (10) arranged on the outlet side of the steam chamber 5 (11) for suction of steam mist, characterized in that the suction zone (12) is also arranged on the sides of the steam chamber (11) to extend to the edge areas of the track and that the steam box (10) comprises edge cutting devices (13) located in the area of the side suction zones (12A) to remove fibers and fillers from edge cutting 10 to prevent contamination of the edges. Steam box according to Claim 1, characterized in that the steam box (10) is arranged at the suction roll (21) on the opposite side of the wire (20). Steam box according to Claim 1, characterized in that the steam box (10) is arranged at the leveling box (24) on the opposite side of the wire (23). I · • «· · · •« I · · * · • «« M · M · · · · · »· ·· · '« # • · · · · · • t I 100413