Papermaking machine that avoids holes in base paper

Abstract

The utility model discloses a papermaking machine for avoiding holes in base paper, comprising a shoe pressure roller, a vacuum roller, a vacuum roller baffle, a baffle and a chemical pipe, wherein the distance between the vacuum roller baffle and the vacuum roller is controlled to be above 250 mm. In the process of producing base paper, the papermaking machine described in the utility model will not produce holes on the paper surface due to water vapor condensation and being brought by airflow onto the felt on the surface of the vacuum roller, regardless of whether the base paper is low-weight or high-weight, and even regardless of the speed of the vehicle.

Description

Technical Field

[0001] The utility model relates to a papermaking machine, in particular to a papermaking machine which can avoid generating holes in base paper. Background Art

[0002] At present, paper needs to be dehydrated and dried during papermaking. When drying, the paper will produce a lot of water vapor. When the water vapor reaches the space between the shoe roller and the vacuum roller, the water vapor condenses and is carried by the airflow to the felt on the surface of the vacuum roller, causing holes on the surface of the base paper, which will affect the quality of the base paper. In addition, the space between the shoe roller and the vacuum roller of the existing paper machine is small. For example, the vacuum roller of the DCT200HS paper machine is only 170mm away from the vacuum roller baffle. During the production process, water vapor condensation is easy to occur, affecting the quality of the paper. The cost of improving the existing papermaking machine is high. The common method to prevent water droplets from dripping is to install a drying device, such as patents CN212801015U, CN109868673B, CN109868673A, CN113622213B and CN113622213A, or to set a water receiving tray, such as patents CN106192527B, CN106192527A and CN205917528U. Utility Model Content

[0003] Purpose of the utility model: The utility model aims to provide a papermaking machine with a simple design and can effectively avoid the generation of holes in base paper.

[0004] Technical solution: The papermaking machine for avoiding holes in base paper described in the utility model includes a shoe pressure roller, a vacuum roller, a vacuum roller baffle, a baffle and a chemical pipe, and the distance between the vacuum roller baffle and the vacuum roller is controlled to be above 250 mm.

[0005] Preferably, the distance between the vacuum roller baffle and the vacuum roller is as large as possible until the vacuum roller baffle contacts the chemical pipe next to it.

[0006] Preferably, the shoe pressure roller is connected to the vacuum roller via a felt and rotates counterclockwise synchronously.

[0007] Preferably, the vacuum roll baffle and the baffle are fixed on the paper machine frame, and the baffle is provided with holes, which are used to allow part of the moisture to escape from the holes and reduce the condensable water vapor.

[0008] Preferably, the size of the hole is ≥400mm*400mm, and the shape of the hole is square, circular or triangular.

[0009] Beneficial effects: Compared with the prior art, the utility model has the following advantages: During the process of producing base paper, no matter it is low-weight base paper or high-weight base paper, and even regardless of the vehicle speed, water vapor condenses and is carried by the air flow onto the felt on the surface of the vacuum roller, causing holes in the paper surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of the papermaking machine of the present invention;

[0011] Figure 2 A schematic diagram of a hole in the paper. DETAILED DESCRIPTION

[0012] The technical solution of the utility model is further described below in conjunction with the accompanying drawings.

[0013] The papermaking machine for preventing base paper from having holes comprises a shoe pressure roller 1, a vacuum roller 2, a vacuum roller baffle 3, a baffle 4 and a chemical pipe 5. The shoe pressure roller 1 is connected to the vacuum roller 2 through a felt and rotates counterclockwise synchronously. The vacuum roller baffle 3 and the baffle 4 are fixed on the paper machine frame. The baffle 4 is provided with a hole 6. The structural schematic diagram is shown in FIG. Figure 1 shown.

[0014] Before the modification of the DCT200HS paper machine, the distance between the vacuum roller 2 and the vacuum roller baffle 3 is only 170 mm. When the distance is less than 250 mm, water vapor condensation will obviously occur, affecting the paper quality. Figure 2 . The utility model controls the distance between the vacuum roller baffle 3 and the vacuum roller 2 to be 250 mm or more by moving the vacuum roller baffle 3 toward the chemical tube 5. However, due to the influence of design and installation space, the chemical tube 5 blocks the moving direction. The greater the distance the vacuum roller baffle 3 moves, the better, and the larger the space will be. At present, the maximum position that can be moved is 270 mm from the vacuum roller, which can increase the volume of the closed area, reduce the condensation of water vapor, and reduce the flow rate of the air flow. At the same time, the vacuum roller baffle 3 is away from the vacuum roller 2, so the water droplets condensed on the vacuum roller baffle 3 will be away from the felt on the surface of the vacuum roller 2, reducing the risk of holes in the base paper surface. At the same time, a square hole 6 is opened at the baffle 4, and the size of the hole 6 is about 400 mm*400 mm. Under the premise of ensuring the above-mentioned baffle 4, the design of the hole 6 allows part of the moisture to escape from the hole 6, reducing the condensable water vapor.

[0015] The papermaking machine for avoiding holes in base paper described in the utility model does not have the problem of holes on the paper surface when producing base paper with grammage of 145g, 150g and 160g at a speed of 1800m / min. Even when producing base paper with a low grammage of 137g, there will be no problem of holes on the paper surface at a speed of 1850m / min.

Claims

1. A papermaking machine for preventing holes in base paper, comprising a shoe press roller (1), a vacuum roller (2), a vacuum roller baffle (3), a baffle (4) and a chemical pipe (5), characterized in that: The distance between the vacuum roller baffle (3) and the vacuum roller (2) is controlled to be above 250 mm.

2. The papermaking machine for avoiding holes in base paper according to claim 1, characterized in that: The distance between the vacuum roller baffle (3) and the vacuum roller (2) is as large as possible until the vacuum roller baffle (3) contacts the chemical pipe (5) next to it.

3. The papermaking machine for avoiding holes in base paper according to claim 1, characterized in that: The shoe pressure roller (1) and the vacuum roller (2) are connected via a felt and rotate counterclockwise synchronously.

4. The papermaking machine for avoiding holes in base paper according to claim 1, characterized in that: The vacuum roller baffle (3) and the baffle (4) are fixed on the paper machine frame.

5. The papermaking machine for avoiding holes in base paper according to claim 1, characterized in that: The baffle (4) is provided with a hole (6).

6. The papermaking machine for avoiding holes in base paper according to claim 5, characterized in that: The size of the hole (6) is ≥400mm*400mm.

7. The papermaking machine for avoiding holes in base paper according to claim 5, characterized in that: The shape of the hole (6) is square, circular or triangular.

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