JPS591837B2 - Paper pulp cleaning and recovery equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In the paper industry, paper has conventionally been recycled from waste paper in the following manner.

First, the waste paper is dispersed in water and turned into pulp using a device called a pulper, and is briefly washed to remove components heavier than pulp, which has a specific gravity of about 1027.

Pulpers are generally used for pulps with low consistency of 5% or less.

At the exit of the pulper, the pulp is filtered through at least one stage of screen, strainer, etc.

The purpose is to remove impurities such as wood chips, plastic chips, metal chips, etc. that may be present in the pulp.

Typically, this process involves at least one slit sieve that removes impurities with dimensions larger than the width of the slit, and a device that allows fibers and flat impurities to pass through. With the perforated sieve,
This is done using a device designed to remove flat impurities.

Usually, devices with sieves with holes of 4 to 57 nrIL and devices with sieves with slits of width 0.3 to Q and 4 m7W are used.

For example, at the outlet of a device called a screen or strainer, as disclosed in French Patent No. 7735151 filed on November 23, 1977, water and fibers are contained, and impurities are A removed clean pulp and a waste component containing a high concentration of impurities are obtained, respectively.

For example, in the apparatus disclosed in French Patent No. 7,735,151, when pulp containing dry ingredients at a concentration of 3 to 5% and about 5% of impurities is inputted, dry pulp flows from the outlet. Contains ingredients at a concentration of 3 to 5%,
A pulp containing approximately 0.05% of impurities was obtained, and a waste component consisting of a pulp containing 30 to 50% of impurities and also a concentration of dry constituents of 3 to 5% was obtained.

Therefore, it can be seen that the waste component still contains a considerable amount of pulp in a highly diluted state.

Therefore, this waste component cannot be discharged, resulting in a troublesome problem.

The most common way to dispose of this waste is to feed it into an auxiliary device called a "sorter," usually consisting of a vibrating sieve, which is then passed through an open screen. , a method of obtaining, on the one hand, washed waste components by washing in a highly diluted state and, on the other hand, a highly diluted pulp that can be recycled.

Such methods have several significant drawbacks.

The first is that the treatment process is carried out in the open, requiring pumping equipment and large amounts of clean water.

This consumes large amounts of energy and water, and the resulting pulp is highly diluted, requiring subsequent reconcentration.

Additionally, the use of vibrating screens requires large concrete foundations to absorb vibrations, as with all vibrating machinery installations, and is expensive to maintain.

Finally, cleaning has to be carried out only with perforated sieves, since, in terms of mechanical strength, slit sieves cannot be applied to vibrating sieves.

Therefore, a considerable amount of the waste components once removed by the strainer passes through the vibrating sieve and is circulated.

The main object of the present invention is to provide a sorter device capable of conveying a washed waste component containing less than 10% paper pulp and washing this paper pulp continuously.

A feature of the device according to the invention is that, by means of a fixed sieve,
A sealed tank is provided which is divided into an inner chamber and an outer chamber, a rotor having vanes is provided in the inner chamber so as to pass near the sieve, and a rotor is provided in the outer chamber at opposite ends of the outer chamber. A spiral wall is provided spanning between the sieve and the tank so as to form a spiral passage around the sieve from the provided pulp inlet to the waste component outlet. .

Moreover, the present invention can also be implemented as follows.

An additional water inlet is provided in the wall of the O interior chamber on the pulp inlet side.

The outer chamber is provided with a helical passage around a fixed sieve, oriented in the same direction as the direction of rotation of the liquid flowing into the outer chamber.

○The direction of rotation of the rotor is opposite to the direction in which this fluid flows, that is, the direction of the spiral passage.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings, with reference to preferred embodiments thereof.

In the drawing, an outer chamber 3 and an inner chamber 4 are separated by a cylindrical horizontal sieve 2.
It is arranged in a sealed tank 1 divided into and an inner chamber 4,
A preferred embodiment of the device according to the invention is shown, consisting of a cylindrical rotor 5 having an axially oriented bee 76 projecting on its outer circumferential surface.

A similar device is also disclosed in French Patent No. 7735151, filed on November 23, 1977 by the applicant.

In the present invention, an outer chamber 3 defined by the sieve 2 and the inner wall surface of the closed tank 1 is partitioned by a spiral wall 7.

The outer chamber 3 therefore forms a spiral passage from the pulp inlet 8 to the waste component outlet 9.

The inlet 8 and the outlet 9 are provided at opposite ends of the spiral outer chamber 3, respectively.

Further, a water inlet 10 communicating with the inner chamber 4 is provided in the end plate 11 on the opposite side of the pulp outlet 120.

The operation of this device according to the invention takes place as follows.

The pulp to be washed enters from the inlet 8 and enters the inner chamber 3.
It is cleaned as it progresses inside.

The fibers pass through the sieve 2, and the pulp from which impurities have been removed is discharged from the outlet 12.

The waste components gradually advance in the outer chamber 3 and reach the final chamber 13.
It remains in the final chamber 13 as long as the pulp 14 immediately upstream thereof is closed.

Periodically, the pulp 14 is opened to remove thoroughly washed and concentrated impurities, and the pulp is completely recovered at the outlet 12.

Since the washing of the waste components is thus carried out under pressure in a closed container, there is no need for a device for circulating the pulp and waste components, which is a drawback in conventional open systems.

Furthermore, in the apparatus according to the present invention, pulp can be input and discharged continuously, except for periodically removing waste components.

Such an advantage was not available with conventional products.

This is because conventional equipment, which was sealed and operated continuously under pressure, was able to separate clean pulp from pulp containing impurities, but was unable to wash away the impurities. be.

The device based on the present invention can have the following preferred configuration.

For example, the spiral wall 7 may be provided from the inlet 8 to the outlet 9 in the same direction as the rotation direction of the pulp in the outer chamber 3.

Naturally, the pulp that has reached the outer chamber 3 flows inside the outer chamber 3 while rotating around the cylindrical sieve 2.

This rotational movement of the pulp is brought about by suitably determining the 50 rotations of the drum, the shape of the holes in the sieve, and the arrangement of the inlets 8, which in this example are oriented tangentially. .

In particular, if the circular holes or slits constituting the holes 15 of the sieve 2 have a cross-sectional shape as shown in FIG. 3, and the vanes 6 have an inclination as shown in FIG.
When the is rotated in the direction shown by Fl in FIG. 3, the pulp in the outer chamber 3 flows while rotating in the direction shown by F2 in the figure due to the reflection of the flow on the side wall surface 16 of the hole 15. It becomes like this.

According to the present invention, the spiral wall 7 winds the rotating sieve 2 from the inlet 8 to the outlet 9 in a direction opposite to the rotational direction of the rotor 5, and the pipes between the inlet 8 and the outlet 9 are , second
As shown in the figure, in the opposite direction to the direction F1 in which the drum 5 rotates, that is, in accordance with the direction in which the liquid rotates and flows,
It is provided tangentially to the tank 1.

Preferably, the helical pitch of the helical wall 7 is smaller than the inner diameter of the inlet 8.

A water inlet 10 is provided for removing (washing) waste components.
It is intended to provide additional water.

This inlet 10 is controlled by the pulp 17 and the amount of water injected is preferably less than 20% of the pulp flow rate reaching the inlet 8.

In this way, the pulp will be sent to the recovery process in the state it is discharged from the outlet 12 without being excessively diluted.

The device according to the invention can also be implemented in a manner different from the embodiments described above.

For example, the device may be provided with a strainer.

The strainer is such that it can be washed in order to recover the pulp it contains from the slag generated in the strainer.

As such a strainer, the strainer disclosed in the above-mentioned French Patent No. 7735151 is suitable.

The device according to the invention can also be used as an improved strainer, feeding pulp directly from the pulper.

However, experiments have shown that during various washing processes, the optimum size of the sieve pores differs for each specific pulp.
You can't necessarily expect good results.

Therefore, it is often preferable to install a soaking device such as the slit type according to the present invention after the hole sieve and the slit sieve, and to use these devices in series.

With such a configuration, waste components can be cleaned using a sorter device having a rotor that is slightly narrower than the strainer and consuming only an economically acceptable amount of energy.

In this way, from a pulp containing 30 to 50% waste components and 3 to 5% dry components, the pulp can have little or no waste components removed.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view schematically showing the device based on the present invention, FIG. 2 is an end view showing the device based on the present invention with the end plate removed, and FIG. 3 shows the rotor vane and sieve. FIG. 3 is a partially enlarged vertical cross-sectional side view showing a preferred embodiment of the hole. 1...Tank, 2...Sieve, 3...
...Outer chamber, 4...Inner room, 5...Rotor, 6...Vane, 7...Spiral wall, 8... ...Entrance, 9...Exit, 10...
...Entrance, 11... End plate, 12...
・Outlet, 13... Final chamber, 14... Valve, 15... Hole, 16... Side wall surface,
17...Valve.

Claims (1)

[Scope of Claims] 1. A sealed tank 1 that is divided into an inner chamber 4 and an outer chamber 3 by a fixed sieve 2, and a vane that passes through the inner chamber 4 near the sieve 2. A rotor 5 having a rotor 5 is provided and in the outer chamber 3 there is a helical winding of the sieve 2 from the pulp inlet 8 towards the waste component outlet 9 which is controlled by the pulp 14. A paper pulp washing and recovery device characterized in that a spiral wall 7 is provided spanning between a sieve 2 and a tank 1 so as to form a passage. 2. Device according to claim 1, characterized in that an additional water inlet 10 leading into the interior chamber 4 is provided on the wall 11 opposite the outlet 12 for the clean pulp. 3. The apparatus according to claim 2, wherein the flow rate of the additional water is 20% or less of the flow rate of the pulp to be washed. 4. Claim 1, characterized in that the spiral wall 7 forms a spiral from the inlet 8 to the outlet 9 in the same direction as the rotating fluid flowing in the outer chamber 3. The device according to any one of items 3 to 3. 5. The sieve 2 is wound around the sieve 2 from the inlet 8 to the outlet 9 in a direction opposite to the rotating direction of the rotor 5. Device.