JPH04110787U - Paper machine headbox rectifier - Google Patents

Abstract

(57) [Summary] [Purpose] In a paper machine head box, even if the length of the straight pipe connected to the curved pipe for feeding papermaking raw materials is significantly shortened, the concentration distribution and flow velocity distribution can be made uniform and high quality can be achieved. Make it possible to manufacture paper. [Structure] A raw material introduction curved pipe 4 for supplying papermaking raw materials to a paper machine head box and an introduction straight pipe connected thereto are provided,
A rectifying plate 17 is provided within the 4 portions of the introduction curved pipe.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is designed to be applied to the paper raw material conveying pipe connected to the head box of the paper machine. The present invention relates to a flow device.

0002

[Conventional technology]

FIG. 6 shows the piping flow of a conventional general paper machine head box. In the figure Pulp slurry 1 in the slurry tank is pressurized by pump 2, and the flow rate is controlled by valve 3. be controlled. Furthermore, after passing through the introduction curved pipe 4 and the introduction straight pipe 5, it passes through the inflow pipe 6 and enters the taper head. Sent to Dar 7. In this case, 10wt% is on the recirculation valve 8 side, and about 90wt% is on the recirculation valve 8 side. Wire 12 driven by roll 13 via perforated plate 9, dispersion section 10 and lip 11 It is squirted on top. The white water dehydrated by this wire 12 passes through the return pipe 14 to the tank. Return to 1.

0003 The piping line from tank 1 to the pump contains a high concentration pulp slurry 15. In is connected and controlled to maintain a constant concentration. It also spews out onto the wire 12. The slurry is mainly pulp that remains on the wire 12 and is dehydrated in the next press process. After drying, it is wound onto a reel to produce paper.

0004

[Problem that the idea aims to solve]

In the conventional head box, the pulp slurry 1 whose flow rate is controlled by the valve 3 is is from the perforated plate 9 to the dividing plate 10 via the inlet pipe 6, and further via the lip 11 to the wire 12. It is squirted on top. At this time, pulp slurry is ejected uniformly on the wire 12 in the width direction of the paper. Otherwise, uneven paper basis weight will occur and the paper quality will deteriorate. Also good paper To obtain quality, the concentration distribution must be uniform in the curved and straight pipes before entering the inflow pipe. We have to let the Lupus rally pass. Conventionally, the concentration was measured in the straight pipe introduced after passing through the valve. Pulp slurry 1 with a uniform distribution becomes a swirling flow in the 4th section of the introduction curved pipe into which it enters next, creating a vortex. If the concentration distribution becomes uneven due to winding, the pulp slurry will be further caused by centrifugal force on the outside of the introducing curved pipe 4. Since the pulp slurry 1 is accelerated, after passing through the introduction curved pipe 4, the pulp slurry 1 becomes homogeneous. I can't get it. For this reason, conventionally, the length of the straight introduction pipe 5 after the bent introduction pipe 4 was set as L=D×5. 7 (D = 500φ to 1000φ), which makes the device unnecessarily large. There were problems such as formatting.

[0005] This invention attempts to solve the above-mentioned conventional problems, and even if the straight pipe is shortened, It is possible to obtain a uniform concentration distribution of the pulp slurry entering the inlet pipe and improve the paper quality. It is an object of the present invention to provide a head box rectifying device that can

[0006]

[Means to solve the problem]

For this reason, the present invention has developed a raw material introduction tube for supplying papermaking raw materials to the head box of a paper machine. A pipe and an introduction straight pipe connected to it are provided, and a rectifying plate is provided in the introduction curved pipe section. This is a means to solve problems.

[0007]

[Effect]

This invention has a rectifier plate installed inside the inlet curved pipe, so that each chamber within the rectifier plate can be controlled individually. This results in concentration non-uniformity, but it is a very small range and is averaged overall. As a result, a uniform pulp slurry can be obtained. Therefore, shorten the introduction straight pipe. is possible.

[0008]

【Example】

The present invention will be explained below with reference to drawings. Figure 1 shows an embodiment of the present invention. , which shows the state in which the rectifying plate 17 is attached to the introduction curved pipe 4. In Figure 1, the introduction song for papermaking raw materials To shorten the length of the introduction straight pipe 16 that connects the pipe 4 and the inflow pipe 6 compared to the conventional one. Then, a rectifying plate 17 is installed inside the bent pipe 4. FIG. 2 shows a front view of the current plate 17. Therefore, the rectifying plate 17 is a combination of a plurality of rectifying plates 17', and its cross section is As shown in Figure 3, the side opposite to the headbox is R, and the fibers in the papermaking raw material are deposited. The structure is designed to prevent product build-up. The thickness t of the rectifying plate 17' is twice the fiber length. This is also to prevent the accumulation of fibers.

[0009] Next, the effect will be explained. In Figure 5, the pulp slurry immediately after the conventional introduction bend pipe 4 To explain the concentration and flow velocity distribution, C indicates the concentration distribution and V indicates the flow velocity distribution. And this These curves are large on the outside of the curved pipe and small on the inside due to swirling flow and centrifugal force. (based on experimental results). However, conventionally, the introduction straight pipe 5 downstream of the curved pipe 4 was used for natural alignment. Because it is flowing, the length of straight pipe 5 needed to be 5 to 7 times the diameter (5 m to 7 m). However, when the current plate 17 is inserted as in the embodiment of the present invention shown in FIG. This results in a uniform concentration distribution C' and a rectified distribution V', making the paper raw material introduction straight and short pipe 16 shorter. I can do it.

0010

[Effect of the idea]

As explained in detail above, the present invention has a rectifying plate installed in the bent pipe for introducing papermaking raw materials. This makes it possible to make the concentration distribution and flow velocity distribution of the pulp slurry uniform, and even the inflow pipe. Even if the length is significantly shortened (for example, 1/2) compared to the conventional one, the effect can be fully demonstrated. Not only can the device be made more compact, but it also eliminates uneven paper basis weight in the paper width direction. It is possible to produce high quality paper.

[Brief explanation of drawings]

FIG. 1 is a side view of a rectifier for a paper machine head box according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line A-A in FIG. 1;

FIG. 3 is a sectional view taken along line B-B in FIG. 2;

FIG. 4 is an enlarged sectional view of the main part of FIG. 1;

FIG. 5 is an explanatory diagram showing the concentration and flow velocity distribution immediately after a conventional curved pipe.

FIG. 6 is a perspective view showing a conventional head box.

[Explanation of symbols]

4 Raw material introduction bent pipe 6 Inflow pipe 16 Introducing straight and short pipe 17 Current plate

Claims (1)

[Scope of utility model registration request] [Claim 1] A paper machine head comprising a raw material introduction curved tube for supplying papermaking raw materials to a paper machine head box, a straight introduction tube connected thereto, and a rectifying plate provided in the introduction curved tube section. Box rectifier.