JP2520191Y2 - Bubble generator for deinking flotation device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel deinking flotation device, and in particular, air is introduced into the raw material liquid to generate bubbles, which are accompanied by rising bubbles in the raw material liquid. When the deinking process is performed by floating the froth and overflowing it from the opening of the cell, it is possible to change the introduced air into fine bubbles without leaking and to generate the bubbles in one direction. -The present invention relates to a bubble generating device of a tation device.

[0002]

2. Description of the Related Art A flotation device is used for the deinking process for removing the ink from waste paper to obtain a raw material for papermaking. The floatation device dissociates the waste paper, mixes air into the waste paper raw material liquid that has been subjected to chemical treatment, and attaches ink particles floating in the raw material liquid to the surface of the generated bubbles to form a floss, which rises. The ink component contained in the raw material liquid is reduced by flotting and accumulating on the liquid surface of the raw material liquid, and removing the accumulated floss. Therefore,
In order to improve the deinking performance, it is important that the total surface area of the bubbles is large, the bubbles are evenly distributed in the raw material liquid, and the retention time of the bubbles in the raw material liquid is long.

The applicant has already proposed such a floating device, and as shown in FIG. 6, the proposed floating device 1 is a cell having an open upper part. Into the inside 3, the raw material liquid S is caused to flow in one direction D, and air is introduced into the raw material liquid S to generate bubbles, and the froth in the raw material liquid is floated along with the rise of the bubbles and overflows from the openings of the cells. Then, the deinking process is performed. In such a flotation device 1, the raw material liquid S rises along with the rise of the bubbles and discharges the bubbles to the liquid surface, and then the raw material liquid S descends. Since the froth is adsorbed in the bubbles, the descending raw material liquid S has the ink component reduced. Air is again introduced into the lowered raw material liquid S to generate bubbles. Thus the same raw material liquid S
Is repeatedly raised and lowered to reduce the ink component each time, and at the same time, is made to flow in the cell in one direction D, so that the raw material liquid S forms a swirling flow R spirally flowing in the cell and goes downstream. Therefore, the ink component is reduced accordingly. On the other hand, air bubbles containing floss discharged to the liquid surface are accumulated and overflow from the opening of the cell.

When a fixed volume of air is mixed in the liquid, the total surface area of the bubbles is inversely proportional to the diameter of the bubbles. Therefore, the smaller the average diameter of the bubbles, the larger the total surface area. Also,
Since the rising speed of the bubbles is almost proportional to the diameter of the bubbles, the retention time is inversely proportional to the diameter of the bubbles when the depth of the liquid is constant. From the above, when a certain amount of air is blown, the chance that the bubbles come into contact with the ink particles and are adsorbed and collected is inversely proportional to the square of the bubble diameter. Therefore, if the bubble diameter becomes small, it will increase dramatically. It will be. That is, it is important to reduce the diameter of bubbles.

Therefore, the applicant of the present invention, as a bubble generating device for generating bubbles, is provided at the inner bottom of the cell so as to extend from the upstream side to the downstream side in the flow direction of the raw material liquid, and ejects air downward. An air jet nozzle that generates bubbles, and a cross-flow type stirring blade that is provided along the nozzle of the air jet nozzle and that atomizes the jetted bubbles to generate a swirling flow along the flow direction of the raw material liquid. We came to research and develop a bubble generator consisting of.

As shown in FIGS. 4 and 5, a bubble generator 3 comprising such an air jet nozzle and a cross flow type stirring blade.
At 0, it is located close to the bottom of the cell 3 and is displaced from the axis of the body 2 so that it extends from the upstream side to the downstream side in the flow direction D of the raw material liquid S and ejects air downward. An air jet nozzle 36 for generating bubbles is provided.
The air ejection nozzle 36 is a tube body that is inserted from the outside of the cell 3, and in the cell 3, the lower side of the tube body is opened in a slit shape to provide an ejection port 29, and the ejection port 29 faces downward. It is provided. Although not shown, the air can be ejected from the ejection port 29 by pressurizing the air from the upstream side of the pipe and introducing the air into the cell 3. An air jet nozzle 36 is provided with a large number of stirring blades 37, which are in contact with the air jet nozzle 36 at the upper end of the rotating surface on the jet side, that is, at the lower side, and which are rotated in the direction toward the axial center of the body 2. A cross-flow type stirring blade 38 having a hollow core is provided. The stirring blade 37 extends from the upstream side to the downstream side in the flow direction D of the raw material liquid, and is formed by extending a predetermined length radially inward from the outer circumference of the cross-flow type stirring blade 38. The stirring blades 38 are arranged along the outer periphery of the stirring blades 38 at predetermined intervals. Cross-flow type stirring blade 3
By rotating 8, the bubble jetted from the air jet nozzle 6 is cut by the stirring blade 37 and stirred to generate fine bubbles.

[0007]

However, in the bubble generating device 30, since the opening 29 of the air ejection nozzle 36 for ejecting air is located above the cross flow type stirring blade 38, the air is ejected. A part of the air is not caught in the cross flow type stirring blade 38, and relatively large bubbles are formed to float. The bubbles that float without being caught are flown from the opening 29 along the rotation direction of the cross flow type stirring blade 38, and thus float from the upstream side of the swirling flow R. In addition, some of the bubbles that have been miniaturized by the cross-flow stirring blade 38 are also separated from the cross-flow stirring blade 38 and swirl flow R
Surface from the upstream.

Of course, most of the air becomes fine bubbles and floats from the downstream side of the swirling flow R. However, a part of the air as described above does not float from the upstream side of the swirling flow R. The problem is that the swirling flow is disturbed and the bubble staying time is shortened and deinking efficiency is lowered.
In addition, the generation of bubbles having a large diameter means that the total bubble surface area is reduced, and the deinking efficiency is reduced, and at the same time, air is uneconomically used, which is a problem.

Further, in order to prevent the bubbles from escaping to the upstream side of the swirling flow in this way, if the air jet nozzle 36 is provided at the side of or below the cross flow type stirring blade 38, the injection port 29 is provided with the cross flow type stirring blade 38. To face to the side or upward. Therefore, the raw material liquid flows into the air ejection nozzle 36 from the ejection port 29 and causes clogging. That is,
The air jet nozzle 36 needs to be located above the cross flow type stirring blade 38 so that the jet port 29 faces downward.

Therefore, an object of the present invention is to solve the above-mentioned problems in order to improve the performance of the flotation device as much as possible, and to generate the air while introducing it into fine air bubbles without leaking. It is an object of the present invention to provide a bubble generation device of a deinking flotation device capable of floating bubbles in one direction.

[0011]

In order to achieve the above-mentioned object, the present invention is provided on the inner bottom of a cell so as to extend from the upstream side to the downstream side in the flow direction of the raw material liquid, and eject air downward. Air jet nozzle that generates bubbles, and a cross-flow stirring blade that is provided along the nozzle of the air jet nozzle and that atomizes the jetted bubbles to generate a swirling flow along the flow direction of the raw material liquid. And a cover member, one end of which is connected to the air jet nozzle and the other end of which covers the suction side upper portion of the cross flow type stirring blade.

[0012]

With the above structure, the air jetted downward from the jet port side of the air jet nozzle is sucked toward the axial center of the cross flow type stirring blade while flowing in the rotational direction of the cross flow type stirring blade. That is, the suction side is formed in the rotation direction of the cross-flow type stirring blade from the jet side of the air jet nozzle. At this time, the air that has not been sucked in is trapped in the cover member because one end is connected to the air ejection nozzle and the other end is covered by the cover member that covers the suction side upper portion of the cross-flow type stirring blade so that the air does not rise. It will be. The air trapped in the cover member is sucked into the cross flow type stirring blade while being guided in the rotation direction of the cross flow type stirring blade.

On the other hand, the fine air bubbles generated by the air being sucked into and stirred by the cross-flow type stirring blade are covered by the cross-flow type stirring blade.
It is emitted in the direction not covered by the member. That is, the bubbles are mainly from the discharge side formed on the opposite side of the suction side of the cross flow type stirring blade,
A part will be discharged from the lower part on the suction side. Since the discharge side of the cross flow type stirring blade faces the downstream side of the swirl flow, the bubbles discharged from the discharge side should be mixed with the swirl flow and help the rise of the raw material liquid to contribute to the formation of the swirl flow. become. In addition, some bubbles released from the lower part on the suction side are
Since it is mixed with the raw material liquid flowing at the bottom of the cell, it is transferred to the downstream side by the swirling flow before it floats. Therefore, some of the bubbles discharged from the lower portion on the suction side also contribute to the formation of the swirling flow by assisting the rise of the raw material liquid similarly to the bubbles discharged from the discharge side.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

The deinking flotation device 51 shown in FIG. 3 is similar to the conventional deinking flotation device 1 in a cell 53 having an open upper portion and a raw material in one direction D. Liquid S
At the same time, the air is introduced into the raw material liquid S to generate air bubbles, and the froth in the raw material liquid is floated along with the rise of the air bubbles and overflows from the openings of the cells for deinking treatment. In the cell 53, a swirling flow R is formed by combining the rotational flow of the raw material liquid S due to the floating of the bubbles and the flow in the direction D. The deinking flotation device 51 is provided with the bubble generating device according to the present invention.

As shown in FIGS. 1 and 2, in the bubble generating device 60, the lower portion of the tubular body is opened in a slit shape so that the injection port 5 is opened.
9, an air jet nozzle 66 provided with 9, a large number of stirring blades 67 extending in the axial direction are arranged at a predetermined interval in the circumferential direction, and a cross flow type stirring blade 68 is formed. One end is connected and the other end is composed of a cover member 40 covering one side upper part of the above-mentioned cross-flow type stirring blade, and it is arranged close to the bottom of the cell 53 shown in FIG. 3 and displaced from the axis of the body 2. Is provided.

The air jet nozzle 66 extends in a tubular shape from the upstream side to the downstream side in the flow direction D of the raw material liquid S, and the lower side portion of the tubular body is used to jet downward air to generate bubbles. Is opened in a slit shape, and a nozzle 59 is provided.

The cross flow type stirring blade 68 is provided along the air jet nozzle 66 on the jet port 29 side. The cross-flow type stirring blade 68 is formed by arranging a large number of stirring blades 67 extending in the axial direction at predetermined intervals in the circumferential direction, and sucking the air jetted from the jet port 59 by rotating the stirring blades 67. Along with this, it is configured so that fine bubbles can be generated and discharged. The cross-flow type stirring blade 68 is rotated at the upper end in a direction A that points toward the axis of the body 2. The direction A side of the injection port 59 is a suction side 41 that mainly sucks air, and the opposite side is a discharge side 42 that discharges air bubbles.

One end of the cover member 40 is connected to the air jet nozzle 59 and the other end thereof is on the suction side 41 of the cross flow type stirring blade 60.
It is provided along the outer periphery so as to cover the upper part.
An air reservoir 43 is defined in the gap between the cover member 40 and the cross flow type stirring blade 60.

Next, the operation of the embodiment will be described.

With the above structure, the air jetted downward from the jet port 59 side of the air jet nozzle 66 is sucked toward the axial center of the transverse flow stirring blade 68 while flowing in the rotational direction A of the transverse flow stirring blade 68. become. At this time, the air which has not been sucked in is covered by the cover member 4 having one end connected to the air jet nozzle 66 and the other end covering the upper part of the suction side 41 of the cross flow type stirring blade 68.
The floating is prevented by 0, and the air is trapped in the air reservoir 43 in the cover member 40. The air trapped in the air reservoir 43 is sucked into the cross flow type stirring blade 68 while being guided in the rotation direction A of the cross flow type stirring blade 68.

On the other hand, the fine air bubbles generated by the air being sucked into the cross flow type stirring blade 68 and being stirred are generated by the cross flow type stirring blade 68.
Is discharged in a direction not covered by the cover member 40. That is, the bubbles are mainly discharged from the discharge side 42 formed on the opposite side of the suction side 41 of the cross flow type stirring blade 68, and a part of the bubbles is discharged from the lower part of the suction side 41. Discharge side 4 of cross flow type stirring blade 68
Since 2 faces the downstream side of the swirling flow R, the bubbles discharged from the discharge side 42 are mixed into the raw material liquid S and help the rising of the raw material liquid S to contribute to the formation of the swirling flow R. Become. Further, some of the bubbles discharged from the lower part of the suction side 41 are mixed with the raw material liquid S flowing at the bottom of the cell 53, and therefore are transferred to the downstream side by the swirling flow R before floating. Therefore, some of the bubbles discharged from the lower part of the suction side 41 also contribute to the formation of the swirling flow R by assisting the rise of the raw material liquid S like the bubbles discharged from the discharge side 42.

As described above, the air jetted downward from the jet port 59 side of the air jet nozzle 66 is once trapped in the air reservoir 43 and then sucked into the cross flow type stirring blade 68. Therefore, a part of the air is not sucked into the cross flow stirring blade 68, and large bubbles are not formed and floated upstream of the swirling flow R. Further, most of the bubbles discharged from the discharge side 42 and some bubbles discharged from the lower part of the suction side 41 are mixed in the raw material liquid S and the raw material liquid S.
To contribute to the formation of the swirling flow R.
That is, it is possible to change the introduced air into fine bubbles without leaking and to levitate the generated bubbles in one direction.

[0024]

[Effect of the Invention] The present invention has the following excellent effects.

(1) Since the introduced air is converted into fine bubbles without leaking, the air can be economically used.

(2) Since all the generated bubbles contribute to the generation of the swirling flow, a good swirling flow can be obtained.

(3) Since all the bubbles float along the swirling flow, the retention time of the bubbles becomes long and the deinking effect is enhanced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a side view showing an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a deinking flotation device including a bubble generating device according to the present invention.

FIG. 4 is a cross-sectional view showing a conventional example.

FIG. 5 is a side view showing a conventional example.

FIG. 6 is a cross-sectional view showing a conventional deinking flotation device.

[Explanation of symbols]

 40 Cover member 51 Flotation device 53 Cell 59 Jet port 66 Air jet nozzle 68 Cross flow type stirring blade D Flow direction of raw material liquid R Swirling flow

Claims (1)

(57) [Scope of utility model registration request] 1. A cell having an open upper portion, in which a raw material liquid is caused to flow in one direction and air is introduced into the raw material liquid to generate bubbles, and the froth in the raw material liquid is caused to accompany the rising of the bubbles. In a flotation device that floats and overflows from the opening of the cell to perform deinking treatment, the inner bottom of the cell is provided so as to extend from the upstream side to the downstream side in the flow direction of the raw material liquid, and is directed downward. An air ejection nozzle that ejects air to generate air bubbles, and air bubbles that are provided along the air ejection nozzle on the ejection port side and are ejected to generate a swirling flow along the flow direction of the raw material liquid. A deinking float, comprising: a cross-flow type stirring blade, and a cover member, one end of which is connected to the air jet nozzle and the other end of which covers the suction-side upper portion of the cross-flow type stirring blade. -A bubble generating device of the device.