JPH0144091B2 - - Google Patents

Description

Detailed Description of the Invention The present invention relates to a dispersion device for producing various dispersions, and in particular, forcibly stirring the media filled in the dispersion chamber to uniformly pulverize various suspensions to be dispersed. The present invention relates to a continuous media type dispersion device for dispersion, and more preferably provides a continuous media type dispersion device suitable for finishing dispersion treatment after preliminary dispersion.

Conventionally, in the manufacturing process of various coating agents such as paints, printing inks, colorants, and cosmetics, it is necessary to pulverize and uniformly disperse pigments, waxes, and other materials to be crushed in a liquid medium such as varnish. Therefore, dispersion devices such as batch roll mills, ball mills, and continuous media mills are used. However, in order to improve the workability of these crushing and dispersing operations, prevent product quality fluctuations, save energy, save space, and have a cost advantage, a continuous media type dispersion device that uses a media is preferable to the batch method. It has been widely used.

A typical one of these conventional continuous media type dispersion devices has a structure as shown in FIG. Figure 1 shows a schematic cross-sectional view of a vertical device, where 1 is the inner wall of the stator, 2 is the media, 3 is the rotating shaft for stirring the media,
4 indicates a stirring member attached to the rotating shaft.

Further, 5 indicates a jacket for cooling and the like.
Here, the suspension to be pulverized and dispersed is continuously fed into the dispersion chamber from the material inlet 6 by a pressure supply means such as a pump as necessary, and the rotating shaft 3
The media 2 is forcibly stirred by the rotation of the stirring member 4, and the material to be crushed, such as pigment, is crushed and dispersed by the shearing force of the media. By the above action of the media, the object to be crushed is finely pulverized and dispersed, and the dispersed suspension that passes through the gaps of the media is separated from the media by the screen 7, which is a media separator, and is discharged. The liquid is continuously discharged from the outlet 8. As the media, spherical bodies made of steel, glass, ceramic, or similar materials are used, and the particle size and filling amount are determined depending on the purpose of grinding and dispersion.

The pulverization or dispersion ability of this media-type dispersion device greatly influences not only its processing capacity but also the quality of the dispersion, depending on how effectively the media applies shear stress to the suspension. Improving media stirring efficiency was a major challenge.

For this reason, for example, the shape of the stirring member may be changed from a pin shape to a disc shape, or holes may be provided in the disc.
By controlling the flow of the media by deforming it into a ring or cam shape, by installing pins on the inner wall of the stator to improve the collision speed difference between the media, and by making the rotation axis thicker, Improvements have been made, such as increasing the circumferential speed on the shaft side of the child.

However, although these conventional improvement measures are effective to some extent in improving the stirring efficiency of the media, they may result in promoting unnecessary wear of the stirring member or the media, or may cause damage to the stirring member, rotating shaft, or There is a large difference in the stirring efficiency of the media in each part of the dispersion chamber, and depending on the passing position of the object to be crushed, the object may be subjected to insufficient crushing and dispersion, resulting in the so-called short pass phenomenon in which coarse particles pass through. This has caused problems in mechanical aspects, quality aspects, work aspects, and even energy efficiency.

Therefore, it may significantly shorten the life of the dispersion device,
The stirring member had to be replaced frequently. In addition, the phenomenon of shot pass of finely ground coarse particles causes variations in the particle size of the objects to be ground in the dispersion, making it difficult to obtain an ideal dispersion that is uniform and has a sharp particle size distribution. For products such as paints and printing inks where the degree of dispersion directly affects the quality and performance of the product, the presence of coarse particles and the broadening of the particle size distribution of the dispersion pose a major problem.

As a result of intensive research to solve the above-mentioned problems of conventional devices, the present inventor has developed an excellent continuous media type dispersion device that solves these problems.

That is, the present invention includes a cylindrical dispersion chamber surrounded by a stator inner wall, a rotor outer wall, and a media separator;
The rotor stirring member is rotatably supported and has a rotor stirring member that protrudes toward the dispersion chamber in the radial direction to continuously crush and disperse the suspension by forcibly stirring the media filled in the dispersion chamber. In a continuous media type dispersion device consisting of a stator having a rotor and a stirring member fixed on the inner wall of the stator that protrudes toward the dispersion chamber, the rotor is located between the upper and lower sides of the stirring members fixed to the inner wall of the stator. Position the agitation member, and find the intersection point D or E of the horizontal line passing through the attachment contact point A or B (Fig. 3) of the stator agitation member and the rotation axis of the rotor, and the midpoint C between points A and B. A QPHI with a trapezoidal cross section is located at a position corresponding to the triangle CIH formed by the triangle CDE separating the rotor outer wall.
A rotor stirring member having the shape of (Fig. 4) is arranged,
Distance between the tip of the rotor stirring member and the inner wall of the stator
Let MC be equal to the vertical distance between the tip of the rotor stirring member and the stator stirring member, and the distance between the tip of the stator stirring member and the rotor outer wall and the distance between the triangular BEC and ADC separated by the rotor outer wall. It is a continuous media type dispersion device with equal to and.

The continuous media type dispersion device of the present invention can be widely used for finely pulverizing and uniformly dispersing materials to be crushed such as pigments and waxes in liquid media such as varnish. It is particularly suitable in terms of workability, machinery, energy efficiency, etc. for producing a dispersion containing particles of up to 5 μm in size, compared to a preliminary dispersion containing particles of about 5 μm.

Below, the continuous media type dispersion apparatus according to the present invention will be explained in more detail with reference to the drawings.

FIG. 2 shows a longitudinal cross-sectional view of a specific example of the dispersion device according to the present invention, which constitutes a dispersion chamber 13 surrounded by a stator inner wall 11, a rotor outer wall 12, and a media separator 21. Media 1 is in dispersion chamber 13.
4, a stator stirring member 16 is installed on the stator inner wall 11, and a rotor stirring member 15 is installed on the rotor outer wall 12.
Attach. A medium passage 19 for cooling or heating is formed on the outside of the stator, and a medium passage 20 for cooling or heating is provided on the inside of the rotor as required. The treated suspension is supplied from the inlet 17 by a pressure supply means, etc., and pulverized and dispersed in the dispersion chamber.
For example, it is separated from the media by the media separator 21, and the treated dispersed suspension is discharged from the discharge port 18. Here, in the apparatus according to the present invention, the mounting position, thickness, length, and shape of the stirring member are adjusted such that the shear rate of each part between the fixed part and the rotating part established in the dispersion chamber approaches a substantially uniform state. etc. shall be stipulated.

FIG. 3 is an enlarged view of a part of the apparatus shown in FIG. 2, and shows the relative relationship between the stator stirring member 16 and the rotor stirring member 15. 22 is rotor 1
This is the central axis of 2. The stirring member 16 fixed to the stator inner wall 11 has a rectangular cross section. A lower contact point A between the stator stirring member 16-1 and the stator inner wall, an upper contact point B between the stator stirring member 16-2 and the stator inner wall, and a horizontal line passing through points A and B and the central axis 22 of the rotor. When the intersections of the two points are respectively D and E, and the midpoint of the points A and B is C, triangles ADC and BEC are formed. In the crushing and dispersion operation, the stator inner wall 11 and the stator stirring member 16 are fixed, and the rotor 12 and the rotor stirring member 15 rotate around the central axis 22 to forcibly stir the media in the dispersion chamber. . The angular velocity of the rotor is ω, and the length from the central axis 22 to the lower point P of the tip of the rotor stirring member 15-2
If EN is _R2 , the circumferential speed υ at the lower point P of the tip of the rotor stirring member is expressed as ω· _R2 . Here, if the angles ADC and BEC of the triangles ADC and BEC are θ, the vertical distance between the lower point P or upper point Q of the tip of the rotor stirring member 15-2 and the corresponding stator stirring member is R ₂ It is expressed as tanθ. The respective shear rates e ₁ between the tip P or Q of the rotor stirring member 15-2 and the N or O of the stator stirring member vertically corresponding thereto are expressed as follows.

e ₁ =ω・R ₂ /=ω・R ₂ / =ω・R ₂ /R ₂・tanθ=ω/tanθ Here, horizontally corresponds to the center point M of the tip of the rotor stirring member 15-2. The shear velocity e ₂ between the stator inner wall points C is expressed as e ₂ =ω・R ₂ /, ==
Then, e ₂ =ω·R ₂ /=ω·R ₂ /=ω·R ₂ / =ω·R ₂ /R ₂ tanθ=ω/tanθ.

If the radius from the rotor central axis 22 to the rotor outer wall point F or G point is R ₀ , the peripheral speed at the rotor outer wall is expressed as ω·R ₀ . Here, the distance between point F or G on the outer wall of the rotor and point J or K at the tip of the stator stirring member is defined as the distance or
When equal to GI, the shear rate e ₃ between point F or G on the outer wall of the rotor and point J or K on the tip of the stator stirring member is: e ₃ = ω・R ₀ / (=) = ω・R ₀ / (=)=ω・R ₀ /R ₀ tanθ=ω/tanθ.

That is, the shear rate e ₁ between, the shear rate e ₂ between, and the shear rate e ₃ between
are the same, and will show a constant value as ω/tanθ. As a result, substantially uniform forced stirring of the media is performed.

As described above, by specifying the installation position, size, and length of the stirring members fixed to the inner wall of the stator and the outer wall of the rotor, it becomes possible to uniformly stir the media, thereby preventing the short pass phenomenon and Blockage phenomenon caused by concentration can be prevented.

The configuration of FIG. 3 can be summarized as follows.

The thickness of the stirring members of the stator and rotor is both d ₁ , the angle θ of the angle BEC and ADC is 0<θ≦20°, and from the following equations (1), (2), and (3), θ and By determining R ₃ and R ₀ , the thickness d ₁ and length (R ₂ − R ₀ ) of the stirring member,
(R ₃ −R ₁ ) can be specified.

R ₀ + R ₀ tan θ = R ₁ (1) R ₂ + R ₂ tan θ = R ₃ (2) d ₁ = 2 × (R ₃ − R ₂ ) tan θ (3) Figure 4 shows the size and shape of the stirring member. A specific example showing the relative relationship between the stator stirring member 16 and the rotor stirring member 15 according to the present invention is shown. The rotor stirring member 15 has a triangular shape.
It is shown in a trapezoidal cross-sectional view corresponding to the hypotenuse of BEC and ADC. If the distance between the tip of the trapezoidal rotor stirring member and the inner wall of the stator is equal to , and the distance between the tip of the stator stirring member and the outer wall of the rotor is equal to , the above conditions are satisfied, and the shear rate is Regardless of the length from the rotor rotation axis 22, it is expressed as ω/tanθ. Furthermore, if the rotor stirring member is made into a trapezoidal shape that is in contact with the hypotenuse of the above-mentioned triangle, the shear rate between the top point J of the stator stirring member and the vertically corresponding point L of the rotor stirring member, for example, is ω・R ₁ /=ω・R ₁ /R ₁ tanθ=
ω/tanθ (however, = R ₁ ). Therefore, the shear rate between the side surfaces L to P of the rotor stirring member and the corresponding side surfaces J to N of the stator stirring member is:
It can be seen that ω/tanθ is constant at any position.

Furthermore, an example will be shown in which a wave-shaped raised body 23 is formed to form a semicircular cross section whose radius is between the stirring members on the inner wall of the stator, or an interval approximately equal to this. By forming the waveform ridges, the distance between the tip of the rotor stirring member and the waveform ridges becomes substantially constant, and the shear rate therebetween also becomes ω/tanθ. Therefore, more uniform stirring of the media is possible.

The configurations of both stirring members in FIG. 4 can be summarized as follows. Both the thickness of the rotor stirring member and the thickness of the stator stirring member at the vertical position of the tip of the stator stirring member are d ₂ , and the angles of the angles BEC and ADC are,
If 0<θ≦20° and the length (R ₃ − R ₂ ) is equal to the length (R ₂ − R ₁ ), then θ and R ₃ are calculated from the following equations (1), (2), and (3). By determining the thickness of the stirring member d ₂
(For rotor stirring members, this means the thickness at the position corresponding to the tip of the stator stirring member.), length (R ₂
−R ₀ ), (R ₃ −R ₁ ), and the rotor outer wall radius R ₀ can be specified.

R ₀ +R ₀ tanθ=R ₁ (1) R ₂ +R ₂ tanθ=R ₃ (2) d ₂ =2×(R ₃ −R ₁ )tanθ (3) =4×(R ₃ −R ₂ )tanθ This As a result, the surface areas of the rotor stirring member and the stator stirring member become approximately equal, allowing more uniform mixing of the media.

As long as the cross section of the stirring member of the stator and rotor satisfies the above conditions, it can be shaped like a cylindrical pin, a conical pin,
Alternatively, it may be a disk type having such a cross section, or a partially cut disk type. The distal end may have various shapes, such as rounded, flat, or variations thereof.

FIG. 5 is a cross-sectional view taken along line AA in FIG. 2, and shows an example of the pin type of both stirring members.

Although FIG. 2 shows an example of the rotor 12, the rotor mounting method can be freely modified as necessary. Furthermore, by passing a refrigerant or the like through the rotor, more efficient heat exchange is possible.

The dispersion device of the present invention having the above configuration can be used for pulverizing and dispersing suspensions made of various materials, and can be expected to have the following effects.

1. Since the shear rate in the dispersion chamber is substantially constant, the uniformity of media distribution is maintained and smooth operation is possible.

2. Shot pass of the dispersed material can be prevented and a dispersion with a sharp particle size distribution can be obtained.

3. Blockage due to media collection is less likely to occur.

4. There is little local wear deformation or destruction of the stator inner wall, rotor outer wall, each stirring member, and media.

[Brief explanation of drawings]

FIG. 1 shows a schematic longitudinal sectional view of a conventional continuous media type dispersion device. FIG. 2 shows a longitudinal sectional view of a specific example of the continuous media type dispersion device according to the present invention. FIG. 3 is a partially enlarged reference drawing showing the relative relationship between the stator stirring member and the rotor stirring member of the continuous media type dispersion device.
FIG. 4 shows a preferred specific example of the relative relationship between the stator stirring member and the rotor stirring member specified in the present invention. FIG. 5 shows a cross-sectional view taken along line AA in FIG. 2. Codes in the figure, 1, 11... Stator inner wall, 2, 14
...Media, 16...Stator stirring member, 7,2
1... Media separator, 12... Rotor outer wall,
6, 17... Material inlet, 15... Rotor stirring member, 8, 18... Discharge port, 22... Rotating shaft, 23
... Wave-shaped raised body, 13 ... Dispersion chamber.

Claims (1)

[Scope of Claims] 1. A cylindrical dispersion chamber surrounded by an inner wall of a stator, an outer wall of a rotor, and a media separator, and a continuous pulverization of a suspension by forcibly stirring the media filled in this dispersion chamber; a rotatably mounted rotor with a rotor stirring member projecting radially towards the dispersion chamber for dispersing, and a fixation having a stirring member fixed on the inner wall of the stator projecting towards the dispersion chamber; In a continuous media type dispersion device consisting of a rotor stirring member, the rotor stirring member is located between the upper and lower sides of adjacent stirring members fixed to the inner wall of the stator, and the attachment contact point A or B of the stator stirring member is set at point A or point B (Fig. 4). The intersection point D or E of the horizontal line passing through and the rotation axis of the rotor
A rotor stirring member whose cross section is trapezoidal QPHI (Fig. 4) is placed at a position corresponding to the triangle CIH formed by the triangle CDE connecting point C and the midpoint C of points A and B separated by the outer wall of the rotor. The distance between the tip of the rotor stirring member and the inner wall of the stator is the vertical distance between the tip of the rotor stirring member and the stator stirring member.
PN is equal to and the distance between the tip of the stator stirring member and the outer wall of the rotor is a triangle.
A continuous media type dispersion device characterized in that the BEC and ADC are separated by the outer wall of the rotor and are equal in distance to each other. 2. Claims characterized in that a wave-shaped raised body (FIG. 4, 23) whose radius is the length from the tip of the rotor stirring member to the stator inner wall member is provided between the stator stirring members. The continuous media type dispersion device according to item 1. 3 The thickness (diameter) d ₂ of the rotor stirring member in the vertical relationship of the tip of the stator stirring member is equal to the thickness (diameter) of the stator stirring member and the following formula d ₂ = 2 × (R ₃ − R ₁ )・tanθ=4×(R ₃ −R ₂ )・tanθ (Fig. 4) However, the continuous media type according to claim 1 or 2 which satisfies 0<θ≦20° Dispersion device.