JPH0523595Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a method for effectively removing impurities from raw materials in paper manufacturing equipment or waste paper processing lines, and recovering useful fibers. This relates to slit screens.

[Conventional technology]

Generally, in paper manufacturing equipment such as paper processing and waste paper processing, screens are constructed of screen plates with slits to remove foreign substances such as stones, sand, metal pieces, and resin pieces from the fiber suspension that is the raw material. A basket is used, and this screen is used as an internal pressure type screen in which the raw material is forced into the screen basket from the inside to the outside in a closed casing to increase throughput, or as an external pressure type screen in which the raw material flows in the opposite direction. In order to improve the screening capacity and dust removal effect, it is known that an agitator such as a blade is rotatably disposed inside or outside the screen basket to provide a screen clogging prevention function and improve the screening effect.

[Problem that the invention attempts to solve]

In this type of slit basket screen, useful fibers are passed through slits formed in the screen plate to remove foreign substances such as impurities, but conventionally, the slits are oriented parallel to the axis of the screen basket, as shown in Figure 5. Because the slits are formed at almost right angles to the raw material flow, useful fibers that are originally intended to pass through to the screen exit end up crossing over the slits, making it difficult to pass through the slits. It has the drawbacks of easily causing clogging problems and lowering processing efficiency. On the other hand, if the slit is made to coincide with the raw material flow, there is a drawback that fibers are likely to be caught at the end of the slit facing the raw material flow, resulting in clogging.

Furthermore, in order to prevent clogging of the screen, the blades of the rotating agitator have approximately the same length as the top and bottom of the screen basket, and are placed approximately parallel to the slits. There was a problem in that pressure fluctuations in pressure and negative pressure appeared as pressure fluctuations (pulsation phenomenon) at the screen outlet, causing problems such as basis weight fluctuations.

The present invention aims to eliminate these conventional problems, and eliminates the screen pulsation trouble and separates useful fibers and foreign substances with remarkable efficiency.The screen cleaning process is also simple, and the screen has a separation function. It is an object of the present invention to provide a screen with a simple construction and low cost that can facilitate greatly improved and efficient processing.

[Means for solving the problem] The present invention uses a drum-shaped screen plate with a large number of slits arranged at a predetermined pitch to separate useful fibers and impurities from a fiber suspension of papermaking raw materials. In a screen using a screen basket surrounded by This papermaking screen is composed of inclined blades, and is characterized in that the agitator changes the moving direction of the raw material to a direction corresponding to the direction of inclination of the slits.

〔Example〕

An example of the present invention will be explained with reference to Figures 1 to 3.
A screen basket 3 surrounded in a drum shape by a screen plate 2 having a large number of slits 1 arranged at a predetermined pitch for separating useful fibers and impurities from a fiber suspension of papermaking raw materials; In this screen, the slits 1 are inclined cuts in the same direction with respect to the raw material moving direction, and the slits 1 are inclined cuts in the same direction as the raw material moving direction, and the raw material of the screen plate 2 is An agitator 4 is provided on the inflow side, and the agitator 4 moves the moving direction of the raw material in an oblique direction corresponding to the direction of inclination of the slit 1 to facilitate the passage of fibers and to minimize clogging.

In this embodiment, the slits 1 have a predetermined length and are arranged in a spiral shape at a predetermined pitch on the body of the screen basket 3, and each slit 1 preferably has an angle of 10 to 45 degrees with respect to the central axis of the screen basket 3. It is formed in such a way that it is tilted in the range of 20 to 30 degrees and follows the same direction as the raw material flow.
It is also possible to form a plurality of rows arranged in a ring shape.

The agitator 4 is an external pressure type in which the raw material flows from the outside to the inside of the screen basket 3 and the agitator 4 rotates outside the screen basket 3. The material flow direction is made to match the inclination of slit 1 with an inclined blade (inclined in the range of 100 to 165 degrees with respect to the central axis), but when the slit 1 is arranged in a spiral, the blade is configured with a spiral shape. Alternatively, an agitator 4 having a rotor structure with blades diagonally provided between ring-shaped spacers may be used. In addition, it is preferable to attach reinforcing parts to the inside of the screen basket 3 using spiral ribs as reinforcing members, which are fixed to the rings at the upper and lower positions. Since there is a relative relationship between the reinforcing member and the reinforcing member, in the case of an internal pressure type slit basket (one in which the raw material flows from the inside to the outside), it is considered that the reinforcing member is placed in the opposite position from the previous example.

The slit 1 is machined to have a tapered cross section and has a slit width of 0.15 to 3.0 mm, preferably 0.15 to 0.8 mm.
It is formed by selecting the processing conditions of concentration, flow rate, and inflow pressure within the range of .

In this embodiment, the casing 6 includes a raw material supply port 7 for supplying the fiber suspension into the casing in a tangential direction, a foreign matter discharge port 8 for continuously discharging the fiber suspension in the tangential direction, and a useful fiber of the paper stock after screening. The screen basket 3 and the agitator 4 are arranged concentrically using a closed vertical cylindrical body equipped with an outlet port 9.
It is a pressure screen with interior decoration.
Further, the agitator 4 is rotatably driven by a rotating shaft 10 via a support member 11.

In the specific example shown in FIG. 4, the slits 1 of the screen basket 3 are arranged in multiple rows in a ring shape, and the agitator 4 is a blade interposed between ring-shaped spacers 5, which are assembled and connected in multiple stages. The blades are configured to be inclined in the opposite direction to the slit inclination so that the material flow is along the inclination direction of the slit 1, and the blades are configured to be inclined in the opposite direction to the slit inclination, thereby reducing the influence on the overall pressure by dispersing it. There is.

[Effect]

Therefore, the raw material supplied into the casing 6 from the raw material supply port 7 flows from the outside of the screen basket 3 toward the inside, and
The agitator 4 rotates on the outside of the screen plate 2, rotates the raw material, and causes the raw material to flow toward the outlet side, and flows the raw material in the direction of inclination of the slit 1 formed at an angle on the screen plate 2, so that the useful fibers are oriented in the direction of the slit. In addition to increasing the vacuum force, only the useful fibers are efficiently flowed inside without clogging and flowed out from the outlet port 9, allowing operation without pulsation and removing foreign substances contained in the raw materials. The foreign matter is blocked by a slit and removed by being pushed toward the reject outlet side, and is discharged from the foreign matter discharge port 8.

[Effect of idea]

In the present invention, the slit is an inclined cut inclined in the same direction as the moving direction of the raw material, and the agitator which determines the moving direction of the raw material in the slit is composed of a blade inclined in the opposite direction to the inclined direction of the slit. By placing it on the inlet side, the screen can be operated without causing any pulsation on the outlet side and without adversely affecting the basis weight.Moreover, since the slits are inclined in the same direction as the raw material flow, useful fibers can pass through easily. The screening ability is significantly improved, efficient screening work is possible, and the concentration of foreign substances is increased.It is also possible to use a screen with fine slits, which reduces the amount of fibers mixed into the tail and increases the recovery rate of useful fibers. This screen has practical effects such as improved dust removal efficiency, more effective screening than conventional screens, and easy and stable operation even with highly concentrated raw materials, greatly improving operability. There is.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of an embodiment of the present invention, Fig. 2 is an enlarged cutaway plan view of a part thereof, Fig. 3 is a vertical cross-sectional view of the used state, Fig. 4 is a side view of another embodiment, and Fig. 4 is a side view of another embodiment. FIG. 5 is a perspective view of a conventional example. 1...Slit, 2...Screen plate,
3...Screen basket, 4...Agitator, 5...Spacer, 6...Casing.

Claims (1)

[Claims for Utility Model Registration] (1) A screen plate 2 in which a large number of slits 1 are arranged at a predetermined pitch to separate useful fibers and impurities from a fiber suspension of papermaking raw materials into a drum-like structure. In a screen using an enclosed screen basket 3, the slits 1 are made to be inclined cuts in the same direction as the moving direction of the raw material, and an agitator 4 is provided on the raw material inflow side of the screen plate 2. 2. A papermaking screen characterized in that the screen comprises a blade that rotates relative to the central axis of the screen basket 3 while being inclined in a direction opposite to the slit 1. (2) A claim for registration of a utility model in which the slits 1 are inclined with respect to the central axis of the screen basket 3, have a predetermined length, and are arranged in a spiral or ring shape at a predetermined pitch on the body of the screen basket 3. The screen as described in item 1. (3) The slit 1 is connected to the screen basket 3
2. The screen according to claim 1 or 2, which is tilted at an angle of 10 to 45 degrees with respect to the central axis of the screen, and is arranged in multiple rows. (4) The screen according to any one of claims 1 to 3, wherein the agitator 4 is a rotor rotatably disposed either inside or outside the screen plate 2. (5) The screen according to any one of claims 1 to 4, wherein the agitator 4 has a rotor structure interposed between ring-shaped spacers 5, 5 and assembled and connected in multiple stages. . (6) The agitator 4 is composed of a spiral blade, and the flow of the raw material is inclined with respect to the central axis of the screen basket 3, so that the inclination of the slit 1 is almost the same as that of the slit 1. The screen according to any of item 4.