JPS6322845B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a pressure roller device for dewatering.

Conventionally, when dewatering pulp wastewater and various types of sludge using a vacuum dehydrator or mesh belt conveyor, pressure was applied with smooth rollers to increase dewatering efficiency. However, when a thick cake layer of sludge adheres to the rotating drum of a vacuum dehydrator or the mesh belt conveyor, sufficient dewatering efficiency cannot be achieved simply by pressing with a smooth roller.

The present inventor completed the present invention as a result of various studies to solve these conventional drawbacks.

That is, in the present invention, a plurality of rollers each having a saw-toothed surface are installed in parallel, and the pitch between the teeth and the depth of the grooves are changed depending on the thickness of the cake layer. This makes it possible to increase dewatering efficiency by applying pressure.

Next, the present invention will be explained with reference to the drawings. FIG. 1 shows one roll of the dewatering press roller device of the present invention. FIG. 1A is a front view of a pressure roll for dewatering, and the surface of the roll has a sawtooth shape 1. The surface layer of this roll is preferably made of a flexible material such as rubber.
For example, the entire roll may be made of rubber, etc.
It is economically preferable to wrap a tooth-shaped rubber sheet around the surface of a metal roll.

By providing a large number of sinking grooves 2 at the apex of the sawtooth shape as shown in FIG. 2, it is possible to improve the sinking of the cake layer. Further, as shown in FIG. 3, the press roll for dewatering of the present invention may have tooth-shaped grooves each having independent diagonal grooves.

In the present invention, the pressure rolls having the toothed grooves are arranged in parallel in order from the first roll on the side into which the cake layer is inserted, in order of the larger toothed grooves and the deeper toothed grooves. As shown in FIG. 2, the pitch A between the tooth grooves is preferably about 10 mm when the thickness of the cake layer is about 20 mm, and the depth B of the grooves is preferably about 4 mm. The pitch A between the teeth of the pressing roll and the depth B of the grooves may be changed depending on the type of cake layer, the thickness of the cake layer, etc.

Further, when using a pressing roll having an inclined groove as shown in Fig. 3, the axis of the second roll is rotated by 90 degrees with respect to the first roll, and the third roll is rotated to the second roll.
By rotating it 90 degrees relative to the roll, a zigzag groove can be cut into the cake layer. Therefore, dehydration efficiency can be increased.

Next, the mode of use of the present invention will be explained. FIG. 4 is a schematic diagram of the vacuum dehydrator. First, the cake layer 4 adhering to the surface of the rotor 3 is pressed by the first roller 5.
The pitch of the sawtooth of the first roller and the depth of the sawtooth groove may be appropriately selected depending on the thickness of the cake layer. The cake layer pressed by the first roller is given a tooth profile by the roller pressing, and the first dehydration is performed. Next, a second roller whose sawtooth pitch is narrower than the first roller and whose groove depth is shallower than that of the first roller.
Further dewatering of the cake layer takes place by further pressing with rollers. Furthermore, by pressing a third roller with a narrower sawtooth pitch and a shallower groove than the second roller, the cake layer can be pressed and the cake layer can be further dehydrated. The number of sawtooth rollers may be appropriately selected depending on the type of cake layer and the thickness of the cake layer. Further, the dewatering press roll device according to the present invention can also be applied to a dewatering device using a mesh belt conveyor.

In addition, when using a sawtooth roller having a shape as shown in FIG. By this, dehydration efficiency can be increased.

[Brief explanation of drawings]

Fig. 1A is a front view showing a sawtooth-shaped roller, B is a side view thereof, Fig. 2 is a partially enlarged view of the roller in Fig. 1, Fig. 3 is a partially enlarged view of the diagonal groove roller,
FIG. 4 is a schematic diagram of the vacuum dehydrator. 1... Sawtooth shape, 2... Biting groove.

Claims (1)

[Scope of Claims] 1. A press roller device for dehydration comprising press rollers having sawtooth profiles arranged in parallel in order from the first roller with the tooth profile pitch A and the tooth profile groove B being larger. 2 Claim 1 in which the tooth profile groove is an independent oblique groove
Press roller device for dewatering as described in . 3. A press roller device for dehydration according to claim 1 or 2, which is provided with a groove inserted into the top of the tooth profile.