JP2727668B2 - Paper machine head box - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a head box of a paper machine.

2. Description of the Related Art Conventionally, as a head box of a paper machine of this kind, there is a head box described in, for example, Japanese Patent Publication No. 58-44800 and Japanese Patent Publication No. 63-42039.

As shown in FIG. 6, an apparatus described in Japanese Patent Publication No. 58-44800 has an intermediate chamber 64 between upper and lower chambers 62 and 63 connected to headers 60 and 61, and the upper and lower chambers 62 and 63 Between the upper and lower slice chambers 65 and 66 connected to each downstream end, the intermediate chamber 64
A zigzag passage 67 is formed at the downstream end of the zigzag passage 67. Projecting lips 69, 70 extending slightly inward from the slice outlet 68 are attached to the downstream end of the zigzag passage 67 to form a head box 71.

In the head box 71, the upper and lower chambers 62,
While supplying the raw materials 72, 73 of medium concentration to the upper and lower slice chambers 65, 66 via 63, the raw material 74 of high concentration is supplied from the intermediate chamber 64 to the zigzag passage 67, and the raw material 74 of high concentration and Of the high-concentration raw material 74 at the upstream and downstream of the slice outlet 68 so as to sandwich the high-concentration raw material 74 from above and below.
Injection is performed between the wires 77 and 78 wound around 5,76 to form a multi-layer web composed of an intermediate layer having high rigidity and an outer coating layer having good printability and the like covering the intermediate layer. .

On the other hand, the one described in Japanese Patent Publication No. 63-42039 is connected to chambers 80, 81, 82 and the upstream end is connected to holes 84, 85, 86 of the upstream tube sheet 83, as shown in FIGS. The upstream tube sheet 83 of the tube group 91 whose downstream end is connected to the holes 88, 89, 90 of the downstream tube sheet 87 is connected to the downstream tube sheet 87. Slices separated into three slice chambers 96,97,98 by separation vanes 94,95
99, each of the holes 88, 89, 90 and each of the slice chambers 96, 97, 98 are connected so as to communicate with each other, and further, inside the separation vanes 94, 95, gas wedges 101, 102 at the slice outlet 100, respectively.
The head box 103 is configured by providing a gas flow path (not shown) for forming the head box 103.

In the head box 103, raw materials 104, 105, 10 are supplied from the respective chambers 80, 81, 82 to the respective slice chambers 96, 97, 98 via the tube group 91.
6, and the raw materials 104, 105, and 106 are jetted from the slice outlet 100 as three-layer jet jets 107, 108, and 109 as shown in FIG. 8, and gas is jetted from gas channels (not shown) of the separation vanes 94 and 95 to form a gas wedge. Forming 101,102,
The jets 107, 108, and 109 are separated from each other for at least a certain distance after being jetted, and then merged to land on the wire 110 so that dewatering can be started so that the jets 107, 108, and 109 are adjacent to each other. An attempt is made to produce a multi-layer web with distinct layers intermingling only between the layers.

[Problems to be Solved by the Invention] However, as shown in FIG.
No. 800, the raw materials 72, 73, 74 are jetted as a jet jet after merging immediately upstream of the slice outlet 68 inside the head box 71, the mixing between the layers is excessive, jet There has been such a problem that turbulence is generated in the jet, leading to a decrease in paper formation.

On the other hand, Japanese Patent Publication No. 63-42039 as shown in Figs.
In the method described in Japanese Patent Application Laid-Open Publication No. H08-157, it is good to apply gas to the paper with low density because the gas enters between the layers positively. However, to apply to the paper with high density, blisters etc. are used when drying with a dryer. In addition, there is a problem that the delamination may easily occur and delamination may easily occur.

The present invention has been made in view of the above circumstances, and has as its object to provide a head box of a paper machine capable of producing high-quality paper free of obstacles such as blisters and delamination.

[Means for Solving the Problems] The present invention relates to a plurality of partition plates which are arranged substantially horizontally with a required interval in the vertical direction in a space formed between a top slice and a bottom slice and having an open end. Thus, a plurality of stages of raw material slicing chambers divided vertically and white water slicing chambers located in the respective raw material slicing spaces are alternately formed, and a rectifier tube connected to the raw material header is connected to each of the raw material slicing chambers. In addition, a white water pipe connected to a white water header is connected to each of the white water slice chambers, and a band-shaped screw plate extending along the flow direction of the raw material is inserted into each of the raw material slice chambers.

[Operation] Therefore, the raw material supplied from the raw material head is rectified by each rectifying tube, then flows into each raw material slicing chamber, and is stirred by the screw plate. The white water supplied from the white water head flows into each white water slicing chamber via each white water pipe, and is jetted from between each jet jet of the raw material.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

1 to 5 show one embodiment of the present invention.
2 shows a head box including a header section 2, a chamber section 3, a dispersion tube section 4, and a slice section 5.

The header section 2 has a plurality of stages (three stages in the figure) in the vertical direction.
Raw material headers 6, 7, 8 each having tapered portions 6 a, 7 a, 8 a, each of which is gradually reduced in width direction (direction orthogonal to the plane of FIG. 1) from the upstream end to the downstream end, The raw material headers 6, 7, 8 are formed from manifolds 9, 10, 11 which extend substantially horizontally at a required pitch in the width direction, respectively, from the downstream end surfaces.

The chamber section 3 is composed of raw material chambers 12, 13, 14 and white water headers 15, 16;
The upper and lower end portions are formed by flat plates 12a, 13a, and 14a arranged in parallel (or in a tapered shape so that an interval toward the downstream end is narrowed) as indicated by the support plates 17 and 18, respectively.
An upstream end is connected to each of the manifolds 9, 10, and 11, and the white water headers 15 and 16 are tapered portions 15a and 16a whose widthwise dimensions gradually decrease from the upstream end to the downstream end.
Having, between the raw material chamber 12, 13 and the raw material chamber 13,
The support plate extending between the white water headers 15 and 16 at a required pitch in the width direction is provided on the downstream end face of each of the white water headers 15 and 16.
Manifolds 19 and 20 passing through 18 are connected.
The white water is a pulp suspension water which is discharged through a wire in a wire part of a paper machine and contains a fine fiber component, a filler and the like.

The dispersion tube portion 4 is formed by an assembly of rectifying tubes 23, 24, 25 and white water tubes 26, 27 whose upstream and downstream ends are respectively supported by an upstream tube sheet 21 and a downstream tube sheet 22 connected to the support plate 18. In each of the flow straightening tubes 23, 24, and 25, the cross-sectional shape changes from a circular shape to a rectangular shape as shown in FIGS. , 14 are connected to the downstream end, each of which is disposed adjacent to each other in the width direction.
The upstream ends of 26 and 27 are connected to the manifolds 19 and 20 of the white water headers 15 and 16, respectively.

The slice section 5 is mainly composed of a top slice 28 and a bottom slice 29. The top slice 28 and the bottom slice 29 form a rectangular space 30 having a cross section that is long in the width direction. The dimension in the thickness direction is gradually reduced toward the side and continues to the slice outlet 31. In addition, the top slice 28 and the bottom slice 29
Each downstream end of each of the slidable in the upstream and downstream direction,
The jet jets 47, 48, and 49, which will be described later, can be adjusted in direction by utilizing the effect of their viscosity. In the space 30,
Partition plate 3 whose upstream end is supported in a cantilever manner on the downstream tube sheet 22
2, 33 and 34, 35, and a plurality of (three in the figure) raw material slicing chambers 36, communicated with the respective straightening tubes 23, 24, 25 by the partition plates 32, 33 and 34, 35, respectively. 37, 38 are formed separately, and between the partition plates 32, 33, a white water slice chamber 39 communicating with the white water pipe 26 and gradually narrowing in the thickness direction toward the downstream opening end is provided. , 35, white water slice chambers 40 communicating with the white water pipe 27 and gradually decreasing in the thickness direction toward the downstream open end are formed. Further, in each of the raw material slicing chambers 36, 37, and 38, a screw-shaped plate 41 formed by twisting a ribbon-like elongated strip extending from the downstream end of each of the straightening tubes 23, 24, and 25 at a required pitch. , 42,43 are inserted.
The screw plates 41, 42, 43 may be separately manufactured from the elongated strips and welded to the downstream ends of the flow straightening tubes 23, 24, 25, or as shown in FIG. The pipe walls 23a, 24a, and 25a are deleted while leaving the pipe walls 23a, 24a, and 25a on the required length on the downstream side of the pipe walls 23 and 24.
A and 25a may be formed by giving a required pitch torsion.

 Next, the operation of the above embodiment will be described.

The raw materials 44, 45, and 46 that have entered the respective raw material headers 6, 7, and 8 flow into the respective raw material chambers 12, 13, and 14 through the manifolds 9, 10, and 11, at which time, the manifolds 9, 10, 11 The influence on the raw materials 44, 45, and 46, which are branched and flowed in the width direction, respectively (for example, variation in concentration) is averaged. From each of the raw material chambers 12, 13, and 14, each straightening tube 23, 24,
The raw materials 44, 45, 46 which have flowed into 25 are promoted in the width direction and are rectified to flow in the width direction while flowing through the flow straightening tubes 23, 24, 25, and have the entire cross section of the dispersion tube portion 4. The flow velocity is made uniform over the entire area. When the raw material 44, 45, 46 exits the dispersion tube section 4 and reaches the slice section 5, the raw materials 44, 45, 46
25, and flows into the raw material slicing chambers 36, 37, 38, and is affected by the screw plates 41, 42, 43, is given a swirling motion and partially surrounds the screw plates 41, 42, 43. Vortex flow is generated. Due to the dispersing action of the raw materials 44, 45, 46 due to the shearing of the swirl flow itself and the shearing due to the mutual interference of the adjacent partial swirl flows, the raw materials 44, 45, 46 maintain the axial flow, the flocs are decomposed, and Slice exit while preventing re-flocking
It is guided to 31 and jetted from the slice outlet 31 as jet jets 47, 48 and 49 shown in FIG.

On the other hand, the white water 50, 51 taken into the white water headers 15, 16 of the chamber section 3 is supplied from the respective manifolds 19, 20 to the respective white water pipes 2.
After flowing into the respective white water slicing chambers 39 and 40 through 6, 27, they are jetted as jets 52 and 53 from the respective downstream ends of the partition plates 32, 33 and 34 and 35 at the slice outlet 31 as shown in FIG.

As a result, in addition to preventing the raw materials 44, 45, and 46 from being flocculated as described above, the jets 52 and 53 of the white water 50 and 51 are mixed with the raw material 4 and 45.
Because it is jetted to each jet jet 47,48,49 of 4,45,46,
The distance at which the separation relationship between each jet jet 47, 48, 49 is maintained can be easily increased, and each jet jet 47, 48, 49
It is possible to produce high-quality paper from a high-concentration raw material with a clear layer that mixes only between adjacent layers without significant disturbance when the 49 and each of the jets 52 and 53 are polymerized. .

In addition, since white water, which is a liquid having fine fibers, is used instead of gas, the adhesive strength between the layers can be improved, obstacles such as blisters and delamination are avoided, and
Noise can also be reduced.

In the above embodiment, the raw materials 44, 45, and 46 are of the same concentration, and as shown in FIG. 1, the slice outlet 31 and each of the screw plates 41, 42,
43 shows an example in which the distance from the tip is substantially the same, but, for example, when the central raw material 45 has a particularly high concentration,
The length of the screw plate 42 may be longer than the others, the distance between the tip of the screw plate 42 and the slice outlet 31 may be shorter than the other, or the number of twists of the screw plate 42 may be increased. Accordingly, each of the screw plates 41, 42, and 43 may be appropriately set.

The head box of the paper machine of the present invention is not limited to only the above-described embodiment, and the flow straightening tube is not limited to one whose cross-sectional shape changes from a circle to a rectangle. It goes without saying that various changes can be made without departing from the gist of the present invention, such as selection of various things such as those that change to.

[Effects of the Invention] As described above, according to the head box of the paper machine of the present invention, each raw material slice chamber is provided with a screw plate extending continuously from each straightening tube, and is ejected from each raw material slice chamber. Since white water is injected between each jet jet of the raw material, even if a high-concentration raw material is used, the raw material can be dispersed by giving a sufficient swirling flow without causing a clogging phenomenon in the raw material slicing chamber. Thus, various excellent effects can be achieved such that high-quality paper having a small amount of flocks and high basis weight can be made, and furthermore, obstacles such as blisters and delamination can be prevented.

[Brief description of the drawings]

1 is an overall side sectional view of one embodiment of the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, FIG. 3 is a sectional view taken along line III-III of FIG. 1, and FIG. FIG. 5 is an enlarged side sectional view of a slice outlet portion, FIG. 6 is a side sectional view of a conventional example, FIG. 7 is a side sectional view of another conventional example, and FIG. 8 is FIG. FIG. 9 is an enlarged sectional side view of a slice exit portion of another conventional example shown in FIG. 1 is a head box, 6,7,8 are raw material headers, 15,16 are white water headers, 23,24,25 are straightening tubes, 23a, 24a, 25a are tube walls, 26,27
Is a white water pipe, 28 is a top slice, 29 is a bottom slice,
30 is a space, 32, 33, 34, 35 are partition plates, 36, 37, 38 are raw material slice rooms, 39, 40 are white water slice rooms, 41, 42, 43 are screw plates, 44,
45 and 46 are raw materials, and 50 and 51 are white water.

Claims (1)

(57) [Claims] 1. A space formed between a top slice and a bottom slice and having an open end is divided in a vertical direction by a plurality of partition plates arranged substantially horizontally at a required interval in the vertical direction. A plurality of stages of raw material slicing chambers and white water slicing chambers located between the respective raw material slicing chambers are alternately formed, and a rectifier tube connected to a raw material header is connected to each of the raw material slicing chambers, and the respective white water slicing chambers are connected. A head box of a paper machine, wherein white water pipes respectively connected to white water headers are connected to each of the raw material slice chambers, and strip-shaped screw plates extending in the flow direction of the raw material are inserted into each of the raw material slice chambers.