JPS6219560B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dewatering device that can be applied to paper manufacturing machines and the like.

FIG. 1 is a schematic side view of a conventional press part. In the figure, part A is the wire part, part B is the press part, and part C is the dryer part. This is the part that is delivered to Part C. 2 is a nip constituted by two press rolls; 3 is a blanket or woven cloth; 4 is a washing device; and 5 is a guide device for the blanket or woven cloth 3.

However, the conventional device shown in FIG. 1 has the following drawbacks. That is, the wet paper 1 is guided to the nip 2 together with a blanket or loose woven cloth 3, and water is forcibly squeezed out.
However, the pressure distribution due to this press roll is
As shown in the figure, the nip width X' is very small and the dewatering time is short.

In the nip mechanism, water is squeezed from the wet paper 1 and the blanket or coarse woven cloth 3 on the nip entrance side from the line connecting the centers of the pair of press rolls. Since it is smaller than that of the cloth 3, rewetting of the wet paper occurs on the exit side, and therefore the amount of water squeezed by one nip is small, making it necessary to employ a plurality of nips.

In order to create a plurality of nips in this way, a large number of press rolls had to be arranged in a row. In addition, it is necessary to install additional equipment such as a cleaning device 4 for the blanket guided to the nip or the coarse woven cloth 3, and a guiding device 5 along with the wet paper 1, which requires a huge amount of equipment cost and area. It was hot.

In addition, in order to extend the water squeezing time and achieve an ideal pressure distribution, we have installed a perforated squeezing plate that gradually narrows the distance between wet paper sheets in the direction of travel. Although this type of dewatering device is also known, the water squeezing mechanism in this dewatering device is merely dewatering by conventional squeezing, and rewetting still occurs at the outlet of the squeezing section, making it impossible to perform sufficient dewatering. It was said that there was no such thing.

The present invention was proposed for the purpose of eliminating the above-mentioned drawbacks of the conventional method, and it extends the water extraction time using the nip, increases the vacuum effect, and further increases the amount of water squeezed by supplying steam. The purpose of the present invention is to provide a dewatering device that can significantly reduce the rewetting ratio and the number of nips, thereby reducing the need for additional equipment, equipment costs, and installation area.

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 3, 4, 5, and 6 are schematic explanatory diagrams of a dewatering apparatus showing embodiments of the present invention.
In the figure, reference numeral 6 denotes a pair of pressure plates, upper and lower, each having a vacuum box 7 or a steam box 8 inside.
Alternatively, in the water squeezing section located in the steam box 8, an endless high-strength belt 11 (for example, a rubber belt) is placed in contact with the pressure plate 6, followed by an endless dewatering felt 12, and a wet paper 1, which are placed in this order so as to be in contact with the pressure plate 6. It has a suction dehydration structure. Further, the high-strength belt 11 and the dewatering felt 12 are porous to facilitate drainage of water.

The pressure contact part of the pressure plate 6 is inclined so as to obtain a wedge effect from the inlet to the outlet, thereby gradually creating a pressure difference. A screw 13 is provided so that the opening degree of the inlet can be adjusted.
Further, at the outlet of the pressure welding part, a pressure device 14 using an air cylinder is attached to one of the pressure plates 6, and this function pressurizes the pressure plate 6 to perform compression dehydration. A high-frequency vibration device 15 is connected to the other pressure plate 6 to apply high-frequency vibration to the pressure plate 6 to smooth the sliding between the pressure plate 6, the high-strength belt 11, and the dewatering felt 12. .

Further, the pressure plate 6 is provided with a large number of holes or elongated holes, and the compressed water transferred from the wet paper 1 to the dehydration felt 12 and the endless high-strength belt 11 flows through the holes or elongated holes of the pressure plate 6 due to the pressure difference. It passes through the elongated hole and is transferred to the vacuum box 7. The vacuum box 7 is divided into a plurality of chambers from the inlet to the outlet of the pressure welding section, and each of the divided chambers is configured to have a different vacuum strength.

FIG. 6 shows a cross section of the steam box 8. Here, steam is sent from one end of the steam pipe 18 at the top of the steam box 8,
It passes through a valve 9 installed at an appropriate pitch (for example, 300 mm), enters a steam box 8 partitioned at an appropriate pitch (for example, 300 mm), passes through a high-strength belt 11, a dewatering felt 12, and blows onto the wet paper 1. Can be attached.
Further, the opening degree of the valve 9 is adjusted by an air cylinder 10.

Now, by spraying steam onto the wet paper web 1, the viscosity coefficient of water in the wet paper web 1 decreases, and the amount of water removed from the wet paper web 1 increases. Further, by partitioning the steam box 8 at an appropriate pitch (for example, 300 mm) and adjusting the amount of steam to each chamber with a valve 9, the amount of water removed from the wet paper web 1 in the width direction can be controlled.

Also, high-strength belt 11 and dehydration felt 12
can be operated continuously by guide rolls 16, and in particular, the high-strength belt 11 is given high tension by rolls 17 installed at appropriate positions, and the wet paper 1 and dewatered felt 12 are It is ready to be squeezed. Moreover, FIG. 4 shows the pressure distribution according to this pressurization method.

As explained in detail above, the present invention forms a wide pressing section with a pressure plate whose pressing section is inclined to obtain a wedge effect and an endless high-strength belt, and in this pressing section, wet paper and Since the dewatered felt is dehydrated by pressing, a much longer dewatering time can be obtained than in the conventional press roll nip, and the amount of dewatering can be increased.

Furthermore, since a pressurizing device using an air cylinder is attached to the pressurizing plate and a vacuum box is provided inside to obtain a large vacuum effect, the amount of water removed can be further increased. As a result of the above, the ratio between the amount of water removed and the amount of wet paper rewet increases, so there is no need for multiple pressing sections as in the past, and a single one is sufficient, and additional equipment can be reduced, resulting in equipment costs. , the installation area can be significantly reduced. In addition, smooth movement between the high-strength belt and the dewatering felt is achieved, and the high-frequency vibration device provided on the pressure plate works effectively, resulting in smooth sliding between the pressure plate and the high-strength belt.

In addition, by providing a steam box, the viscosity coefficient of water in the wet paper decreases, and the amount of water removed increases.
Since the temperature of the wet paper when it enters the dryer section is higher, the amount of steam consumed in the dryer section is reduced. Furthermore, by controlling the flow rate of steam from the steam box at an appropriate pitch in the width direction, it is possible to make the moisture distribution of the final product of paper uniform.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an example of a conventional press part, FIG. 2 is an explanatory view showing the pressure distribution by the Nipprol shown in FIG. 1, and FIG. 3 is a side view of a dewatering device showing an embodiment of the present invention. FIG. 4 is an explanatory diagram showing the pressure distribution in FIG. 3, FIG. 5 is a cross-sectional view of a main part in FIG. 3, and FIG. 6 is a cross-sectional view along the line shown in FIG. Explanation of the main parts of the diagram, 1... wet paper, 6... pressure plate, 7... vacuum box, 8... steam box, 11... high strength belt, 12... dehydration felt, 14... pressure device .

Claims (1)

[Claims] 1. It has a vacuum box and a steam box, is equipped with a pressurizing device using an air cylinder, has a pressurizing plate with an inclined pressing part to obtain a wedge effect, and an endless porous high-strength belt. 1. A dewatering device characterized by forming a pressing section and compressing and suction dehydrating wet paper and dewatered felt in the pressing section.