JPH06316886A - Pressure-type flotation machine - Google Patents

Abstract

PURPOSE:To provide a flotation machine improved in deinking ability by raising the trapping rate of floating fine bubbles. CONSTITUTION:One end of a flotation cell 11 is provided with an inlet 12 for stock liquor containing ink particles and bubbles and the other end with a froth outlet 14 fitting a partition plate 19 with its upper part opened. Inside the flotation cell 11, the space is divided into the upper flow channel 20 and lower flow channel 21 through a partition wall 15 extended horizontally from the lower part of the inlet 12, both the flow channels communicate with each other at the latter end, forming a U-turn flow channel. The inlet 12 side of the lower flow channel 21 is provided, at the bottom, with an outlet 13 for treated liquor and with an accept bypass port 16 above said outlet 13. Good- quality stock can be taken out through the outlet 13, while the bubbles gathered on the lower surface of the partition wall 15, together with part of pulp liquor, through the accept bypass port 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flotation machine suitable for deinking waste paper.

[0002]

2. Description of the Related Art As a pressure type flotation machine, one shown in FIG. 4 has been proposed. In this flotation machine, an inlet 12 is provided at one end of a cylindrical levitation cell 11, and a high-quality raw material outlet 13 and a floss outlet 14 are provided at the other end, and the treatment liquid 1 entering from the inlet 12 floats bubbles 2. While traveling through the floating cell, it is discharged from the discharge port. This flotation machine is epoch-making in that it makes it possible to positively utilize fine bubbles, but it is somewhat insufficient in terms of floating fine bubbles of 100 μm or less.

Looking at the flow in the cell, the flow is from the inlet 12 to the outlets 13 and 14 as a whole, but the flow velocity in the upper part of the flow path becomes higher than that in the lower part due to the acceleration effect due to the rise of bubbles, and A circulating flow as shown in FIG. 4 was generated. The bubbles floating from the retrograde flow in this circulation flow were reintroduced into the anterograde flow and circulated as shown in the figure, and the floating ability in the cell was diminished.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a pressure type flotation machine which improves the decapsulation performance by improving the floating capture rate of fine bubbles.

[0005]

[Means for Solving the Problems]

1. As a result of the bubble distribution measurement using the simulated liquid by the present inventors, it was found that the number of bubbles was small at the lower part of the inlet, which was the end point of the retrograde flow in the cell. In the present invention, a discharge port is provided below the introduction port in order to discharge the good quality raw material from the smallest bubble point in the cell, and the inside of the cell is U-turned from the upper flow path to flow to the lower flow path.

2. A partition wall is provided in the cell so that bubbles floating from the retrograde flow in the circulation flow generated in the cell are not mixed into the forward flow, and a floss discharge port for taking out the bubbles accumulated on the lower surface of the partition wall is provided.

Based on the above idea, in the pressure type flotation machine according to the present invention, the inside of the levitation cell is divided into an upper flow path and a lower flow path by a partition wall, and the upper flow path in the levitation cell has a raw material liquid at one end. The upper flow path and the lower flow path communicate with each other at the other end in the flotation cell, and the lower flow path has a processed raw material liquid discharge port at the bottom on one end side and an upper part on the one end side. Adopt a structure with a floss outlet.

[0008]

Most of the bubbles float in the upper channel in the same manner as in the conventional case and are discharged from the floss discharge port. Some of the remaining fine bubbles float in the lower channel and gather on the lower surface of the partition wall, and then are taken out together with a part of the pulp liquid and subjected to the flotation treatment again. The high-quality raw material with air bubbles released is discharged from the high-quality raw material outlet and sent to the next process.

With these functions, the amount of bubbles contained in the discharged good quality raw material can be almost halved. Further, the effect on deinking is shown in FIG. 3, and according to the flotation machine of the present invention, the deinking rate is considerably improved, and the effect of the present invention can be seen. It should be noted that the bubbles in the pulp liquid taken out from the lower part of the partition wall are bubbles that are large enough to aggregate and coalesce in the process and float in the upper flow path in the next processing step. It was confirmed by experiments that no problem such as the accumulation of

[0010]

EXAMPLE An example of the flotation machine according to the present invention shown in FIGS. 1 and 2 will be described below. First, the embodiment shown in FIG. 1 will be described. A high-quality raw material discharge port 13 is provided below the introduction port 12, and a horizontal partition wall 15 is provided at an intermediate portion in the vertical direction so that the raw material liquid flowing from the introduction port 12 makes a U-turn downward from the upper flow path 20 at the other end side. Then, the lower flow path 21 that returns to the introduction port 12 side is formed, and the bubbles that have floated up in the lower flow path 21 and collected on the lower surface of the partition wall 15 are the accept bypass port 1
After being taken out together with a part of the pulp liquid from No. 6, it is mixed into the feed material (not shown) and again subjected to the flotation treatment. Inlet 12
Inside the levitation cell 11 on the opposite side, a floss discharging means having a floss discharging port 14 is provided which is partitioned by a partition plate 19 having an open top. The floating cells 11 configured as described above are connected in series by a predetermined number (the number of stages) to perform the deinking process.

Next, another embodiment shown in FIG. 2 will be described. The amount of air bubbles gathering on the lower surface of the partition wall 15 is small in quantity, and the air bubbles themselves are not sufficient to give a levitation force to the pulp liquid and to flow out from the levitation pipe 18.
The levitation promoting air 17 is supplied from the outside to the inlet of the air bubble, and the pulp liquid containing a lot of minute bubbles is pushed up to the vicinity of the froth layer of the upper flow path 20 via the levitation tube 18 to facilitate the levitation of the bubbles. . Other configurations and operations are similar to those shown in FIG.

[0012]

As described above in detail, in the pressure type flotation machine according to the present invention, the inside of the levitation cell is divided into an upper flow passage and a lower flow passage by a partition wall, and the upper flow passage has one end. The upper flow path and the lower flow path communicate with each other at the other end in the levitation cell, and the lower flow path has a processed raw material liquid discharge port at the bottom on one end side and one end side. A froth discharge port is provided on the upper part of this, which improves the floatation capture rate of fine bubbles in the floating cell while the raw material liquid flows through the upper and lower flow paths, improving the deinking performance, It is effective as it enables the production of high quality recovered waste paper pulp with less ink.

[Brief description of drawings]

FIG. 1 is a sectional view of a flotation machine according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a flotation machine according to a second embodiment of the present invention.

FIG. 3 is a graph of experimental results showing the effect of ink removal rate of the device according to the present invention.

FIG. 4 is a cross-sectional view showing a conventional flotation machine.

[Explanation of symbols]

 1 Treatment Liquid 2 Bubbles 11 Floating Cell 12 Inlet 13 High Quality Material Outlet 14 Floss Outlet 15 Partition Wall 16 Accept Bypass Port 17 Flotation Promoting Air 18 Flotation Pipe

Front page continuation (72) Inventor Ryojiro Katsube 1-1, Shoucho, Mihara-cho, Hiroshima Prefecture Ryoshige Mihara Engineering Co., Ltd.

Claims (1)

[Claims] 1. A raw material liquid introduction port containing ink particles and bubbles is provided at one end, and a floss discharge means partitioned by a partition plate having an upper opening at the other end, and the inside is divided into an upper flow path and a lower flow path. There is a levitation cell divided by a wall, the upper flow path in the levitation cell communicates with the raw material liquid inlet at the one end, and the upper flow path and the lower flow path are the other in the levitation cell. A pressurizing type floater characterized by being connected to each other at the end and having a treated raw material liquid discharge port at the bottom of the one end side and a froth discharge port at the upper end of the one end side in the lower flow path. Selection machine.