DE102022131936A1 - Suction box - Google Patents

Abstract

The invention relates to a suction box (10) for removing a liquid from a moving structure or web (3), with a housing (1) in which a roller (2) is rotatably mounted, wherein the housing (1) has an opening (1b) which is arranged such that at least a region of a surface (2a) of the roller (2) is exposed, so that the moving structure or web (3) is supported on the surface (2a) of the roller (2), wherein the roller (2) has a first inner sieve (20) and a second sieve (21) arranged thereon.

Description

The invention relates to a suction box for removing a liquid from a moving structure or web, comprising a housing in which a roller is rotatably mounted, the housing having an opening arranged such that at least a region of a surface of the roller is exposed, so that the moving structure or web is supported on the surface of the roller.

Such a suction box is, for example, from the EP 1 851 377 B1 known.

The object of the present invention is to further develop the suction box mentioned at the outset in such a way that an even better dewatering of a moving structure or web can be achieved.

This object is achieved according to the invention by a suction box for removing a liquid from a moving structure or web, with a housing in which a roller is rotatably mounted, wherein the housing has an opening which is arranged such that at least one area on the surface of the roller is exposed so that the moving structure or web is supported on the surface of the roller, wherein the roller has a first inner screen and a second screen arranged thereon.

The roller is therefore an open roller. Liquid can penetrate the roller. In particular, the roller casing is open and permeable to water. With such a suction box, even dewatering can take place across the width of the web. A significantly improved water line, in particular a straighter water line, is achieved. It is possible to suck in chemicals, fillers, ink, etc. from one side of the paper web, as a long suction zone is available.

The second sieve can be finer than the first sieve. In particular, the first sieve serves as a support sieve, which carries the second, finer sieve on top of it. There is preferably no gap between the first and second sieves. They lie directly on top of each other. This allows particularly good water drainage.

The first sieve and/or the second sieve can be made of wire, in particular stainless steel wire, bronze wire or plastic wire. The sieves are preferably made of metal in order to achieve low wear.

The first sieve can have three to six, preferably 4.5 wires per centimeter. The second sieve can have 12 to 16, preferably 14 wires per centimeter. Depending on the application, the number of wires per centimeter can be selected to suit the first and second sieve.

The first sieve can have a wire with a diameter in the range 0.3 mm to 0.6 mm, preferably with a diameter of 0.45 mm. The second sieve can have a wire with a diameter in the range 0.1 mm to 0.4 mm, in particular 0.25 mm. This means that the second, i.e. outer sieve has wires with a smaller diameter than the first sieve.

Particular advantages arise when the roller is driven by a drive. This can reduce friction on the roller. In particular, the outside of the roller can have the same speed as the structure or the web that is pulled over the roller. This means there is no friction and therefore no abrasion. If the roller is driven, the tension of the screens of a paper machine, especially wet or forming screens, can be greatly reduced, in particular to around 50% of the tension without a drive. This means that finer screens with higher retention can be used. The service life of the screens is extended. The camber of the rollers is reduced. This creates a frictionless suction box. A running regulator is not necessary.

A spray pipe can be installed in the roller to clean the roller. This can prevent the roller's screens from becoming clogged and thus prevent parts of the area from being drained.

Preferably, a drive is provided for the oscillating movement of the spray pipe. This ensures that the roller can be cleaned over its entire length by the spray pipe.

Sealing and/or covering means can be provided to adjust the suction width. This means that the suction box can be used for webs of different widths.

A pump, particularly a vacuum pump, can be connected to a suction box. The pump can suck out liquid that has been absorbed by the roller. Alternatively, a blower with a water separator can be provided.

With the suction box according to the invention, the dry content of the web or structure can be significantly increased.

An even further increase in the dry content is possible if several, in particular two or three, suction boxes are arranged in a cascade. The web or structure then runs over several suction boxes arranged one after the other, with liquid being drained through each suction box. This allows the web or structure to be dried particularly well and effectively.

Further advantages of the invention emerge from the description and the drawing. Likewise, the features mentioned above and those described below can be used individually or in combination in any desired way. The embodiments shown and described are not to be understood as an exhaustive list, but rather are exemplary in nature for describing the invention.

• 1 einen Saugkasten;
• 2 eine Schnittdarstellung durch einen Saugkasten;
• 3 eine Stirnseitenansicht einer Walze;
• 4 eine Saugkastenanordnung.

Show it:

• 1 a suction box;
• 2 a cross-sectional view of a suction box;
• 3 a front view of a roller;
• 4 a suction box arrangement.

The 1 shows a suction box 10 with a housing 1 in which a roller 2 is mounted so as to be rotatable about an axis of rotation X. The surface 2a extends through an opening 1b of the housing 1, which is formed by two upper housing sections 1a. A web 3 is guided over the suction box 10. The web 3 is in contact with the surface 2a of the roller 2. The roller 2 can be driven by a drive (not shown). The rotational speed of the roller 2 can be set and/or regulated.

A cover 7 is indicated with which the suction box 1, in particular its slot-like opening 1b, can be covered in order to thereby reduce the suction width and in particular to be able to dewater narrower webs 3.

In the presentation of the 2 it can be seen that the suction box, in particular at its lower end, has a pump 13 through which liquid that collects at the bottom of the suction box 1 can be drained. The pump 13 can be a vacuum pump. Alternatively, a fan with a water separator can be provided. A suction pipe 9 is also indicated. The suction pipe 9 is positioned at the bottom of the suction box 1 to ensure a water level that is below the roller 2, so that re-moistening is prevented.

The 2 it can be seen that a spray pipe 15 is arranged in the roller 2, through which cleaning liquid can be sprayed from the inside against a casing 2b, ie an inner first screen. This serves to clean the casing 2b.

From the 3 It follows that the casing 2b of the roller 2 is formed from an inner first screen 20 and an outer second screen 21. The screens 20, 21 lie against one another. In particular, the first screen 20 forms a support screen for the outer screen 21. The outer screen 21 is finer than the inner screen 20. The inner screen 20 is supported on a support structure 22 of the roller 2. The screens 20, 21 are hollow cylindrical.

The 4 shows a cascade of three suction boxes 10 over which a web 3 runs. This allows particularly effective dewatering of the web 3 and increases its dry content.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely to provide the reader with better information. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• EP1851377B1 [0002]

Claims (13)

Suction box (10) for removing a liquid from a moving structure or web (3), with a housing (1) in which a roller (2) is rotatably mounted, the housing (1) having an opening (1b) arranged such that at least a region of a surface (2a) of the roller (2) is exposed so that the moving structure or web (3) is supported on the surface (2a) of the roller (2), characterized in that the roller (2) has a first inner sieve (20) and a second sieve (21) arranged thereon. Suction box after Claim 1 , characterized in that the second sieve (21) is finer than the first sieve (20). Suction box according to one of the preceding claims, characterized in that the first sieve (20) and/or second sieve (21) is made of wire, in particular stainless steel wire, bronze wire or plastic wire. Suction box after Claim 3 , characterized in that the first sieve (20) has 3 to 6, preferably 4.5 wires per cm. Suction box after Claim 3 or 4 , characterized in that the second sieve (21) has 12 to 16, preferably 14 wires per cm. Suction box according to one of the Claims 3 until 6 , characterized in that the first sieve (20) has a wire with a diameter in the range 0.3 mm to 0.6 mm, preferably with a diameter of 0.45 mm. Suction box according to one of the preceding Claims 3 until 7 , characterized in that the second sieve (21) has a wire with a diameter in the range 0.1 mm to 0.4 mm, in particular 0.25 mm. Suction box according to one of the preceding claims, characterized in that the roller (2) is driven by a drive. Suction box according to one of the preceding claims, characterized in that a spray pipe (15) for cleaning the roller (2) is arranged in the roller (2). Suction box after Claim 9 , characterized in that a drive is provided for the oscillating movement of the spray pipe (15). Suction box according to one of the preceding claims, characterized in that sealing and/or covering means (7) are provided for adjusting the suction width. Suction box according to one of the preceding claims, characterized in that a pump (13) or a blower with water separator is connected to the housing (1) of the suction box (10). Suction box arrangement in which several, in particular two or three, suction boxes (10) are arranged in cascade according to one of the preceding claims.

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