JP2672817B2 - Mixing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a mixer for agitating and mixing materials such as powders and granules or powders and granules and liquid in a batch manner at high speed. <Prior Art> As a mixing method of materials such as powder and granules, there is a mixing method using various mixers such as a container rotating type mixer and a container fixed type batch type or continuous type mixer. In particular, in the case of stirring and mixing powders and granules at high speed, a container-fixed type batch-type high-speed mixer is used. This high-speed mixer generally puts a certain amount of powder and granules to be mixed into a fixed container, and rotates various types of stirring blades installed in the container at high speed (about 500 to 10,000 rpm) to form powder and granules. Mixing is performed by forcibly flowing and stirring the body. This high speed mixer includes a Henschel mixer, a high speed mixer, a fine mixer and the like. By the way, in such a high-speed mixer, improvement of the degree of mixing is an issue. Particles with a relatively small particle size (hereinafter referred to as "powder" or "fine powder")
With relatively large particle size (hereinafter referred to as "powder")
However, powders, particularly fine powders, are easily aggregated (blocked), and when mixed in an aggregated state, the degree of mixing is reduced. In the above-described conventional high-speed mixer, since the powders are mixed by the flow of the powders, the powders are mixed in an agglomerated state, that is, in the form of lumps, and thus the degree of mixing is low. Therefore, as shown in FIG. 3, crushing means 30 having multi-stage blades 301 that rotate at high speed in a box-shaped casing 29 is separately provided on the side of the casing to crush powders that are agglomerated at the same time during the mixing of powder particles. Mixer that can be crushed (MGT mixer) 28
Has been proposed. However, in this mixer, since the powder particles are crushed at the same time during mixing, for example, when the powder X and the powder Y which are aggregated are mixed, the powder X is provided near the multistage blade of the crushing means. And Y are present, the agglomerated powder X is not efficiently crushed. In particular, when the mixing ratio of the powder Y is high, the probability of the powder X colliding with the multi-stage blade becomes low, and it becomes difficult to disintegrate the powder X. Therefore, it is necessary to crush the agglomerated powder X before mixing the powders X and Y. <Problems to be Solved by the Invention> An object of the present invention is to solve the above-mentioned drawbacks of the prior art,
It is to provide a mixer capable of increasing the degree of mixing. <Means for Solving Problems> In order to achieve such an object, the inventors of the present invention have conducted intensive studies and as a result, crushed and / or crushed a material (particularly a powder) in the vicinity of a material inlet in a casing. The present invention was accomplished by providing a crushing / dispersing means for dispersing, crushing / dispersing the powder by the crushing / dispersing means immediately after charging the powder, and then finding a mixer for mixing. That is, the present invention has a material inlet and outlet,
A casing having a spherical interior, a crushing / dispersing unit installed near the charging port in the casing for crushing and dispersing the material charged from the charging port, a shaft, and a multi-stage blade attached to the shaft. A stirring device for stirring and mixing the materials crushed and dispersed by the crushing and dispersing means, and a scraper that rotates along the inner wall of the casing. And a drive means for rotating the scraper, and a material scraping means for scraping off the material adhering to the inner wall of the casing, wherein the shaft and the scraper rotate concentrically and independently of each other. The present invention provides a mixer characterized by being installed. The crushing / dispersing means is preferably a rotor attached to the tip of the shaft of the stirring device and provided with a plurality of projections. The scraper preferably has an elastic member having a ring shape and being in contact with the inner wall of the casing. The scraper is preferably rotationally driven at a lower rotation speed than the shaft of the stirring device, the rotation speed of the shaft of the stirring device is 300 ~ 10,000 rpm, the rotation speed of the scraper is 10 ~ 100 rpm. Good to have. Hereinafter, a preferred embodiment of the mixer of the present invention shown in the accompanying drawings will be described in detail. FIG. 1 is a partial sectional front view of the mixer 1 of the present invention. As shown in the figure, the mixer 1 has a predetermined volume necessary for mixing the materials, and the inside thereof has at least a spherical casing 2. The reason why the internal shape of the casing 2 is spherical is as follows. Firstly, the surface area of the inner wall of the casing can be minimized in order to ensure a certain volume, which suppresses the adhesion of material to the inner wall and secondly the casing 2
It is possible to eliminate the dead zone inside, prevent the material from staying, and increase the mixing degree. An input port 3 for inputting the material is provided at the upper part of the casing 2, and a discharge port 4 for discharging the mixed material is provided at the lower part. Since the mixer 1 of the present invention is used in a batch system, it is necessary to seal the casing 2 during mixing of the materials, and therefore the material input port 3
The lid 5 and the lid 6 are attached to the outlet 4 and the outlet 4, respectively. The lids 5 and 6 are opened and closed at a predetermined time. Such a casing 2 includes a stirring device 7 and a casing 2 for stirring or stirring and mixing the materials in the casing.
Material scraping means 16 for scraping off material adhering to the inner wall 25 of
Is installed. The structures of the stirring device 7 and the material scraping means 16 will be described below. The stirring device 7 has a shaft 8 protruding into the casing 2 by a predetermined length, and stirring blades, preferably multistage blades 9 are fixed to the tip portion of the shaft 8 at regular intervals. The number and the number of stages of the stirring blades (multi-stage blades) 9 are not particularly limited, and the plane shape of the blades may be any shape such as a triangle or a rectangle, and may have a triangular cross section, a flat blade or a bent blade. Any of those having a twist may be used. The shaft 8 is rotatably supported by bearings 10 inside a hollow shaft 18 which is a rotary shaft of a scraper 17, which will be described later. A pulley 12 is fixed to a base end portion of the shaft 8, and a belt 13 is hung between the pulley 12 and a pulley 14 fixed to a rotation shaft of a motor 15 which is a drive source.
The rotational force of the motor 15 can be transmitted to the shaft 8. On the other hand, the material scraping means 16 has a hollow shaft 18, and a scraper 17 that rotates along the inner wall 25 of the casing 2 is attached to the tip of this hollow shaft 18. The scraper 17 is composed of a ring-shaped member 171 having an outer diameter slightly smaller than the inner diameter of the casing, and a plurality of elastic members 172 attached to predetermined positions of the ring-shaped member 171.
When the scraper 17 is rotated, each elastic member 172 slides while coming into contact with the inner wall 25 of the casing 2 to scrape off the material attached to the inner wall 25. The elastic member 172
The ring-shaped member 171 may be arranged so as to cover the entire inner wall 25 of the casing by each elastic member 172 when the scraper is rotated once as shown in FIG. The elastic member 172 is made of, for example, a rubber material such as urethane rubber or a resin such as Teflon, and preferably has excellent wear resistance. The scraper 17 is not limited to the one having the above-described structure, and may be any one such as a ring-shaped member having a brush attached thereto. The hollow shaft 18 is axially supported by bearings 19 and 19 inside a sleeve 26 formed in the lower portion of the casing 2. The shaft 8 is inserted inside the hollow shaft 18 and the hollow shaft 18 is supported by the bearings 10 and 10. It is pivoted on 18. That is, the shaft 8 of the stirrer and the hollow shaft 18 of the scraper rotate concentrically. With such a structure, the mixer 1 can be downsized. A pulley 21 is fixed to the base end of the hollow shaft 18,
A belt 22 is hung between the pulley 21 and a pulley 23 fixed to the rotating shaft of a motor 24 that is a drive source,
The rotational force of the shaft can be transmitted to the hollow shaft 18. In addition, between the upper portion of the sleeve 26 and the hollow shaft 18, and between the tip of the hollow shaft 18 and the shaft 8,
In order to prevent the material in the casing 2 from getting wet,
Ring-shaped sealing members 20 and 11 are mounted, respectively. Such seal members 20 and 11 include, for example,
A rubber O-ring, a rubber V-ring, an oil seal, etc. are used. In the configuration example shown in FIG. 1, the shaft 8 and the hollow shaft 18 are rotated by two motors 15 and 24, respectively, but both shafts 8 and 18 are rotated by one motor.
May be configured to rotate. The transmission of the rotational force to the shafts 8 and 18 is not limited to the case where the mechanism using the pulley and the belt is used, and other power transmission means such as a gear may be used. The shaft 8 and the hollow shaft 18 may rotate in either direction. Of these, the hollow shaft 18 rotates clockwise, stops, rotates counterclockwise at predetermined fixed intervals,
It is advisable to repeat the rotation with one stop cycle.
The reason is that the scraper 17 attached to the tip of the hollow shaft 18 changes its rotation direction at a predetermined interval, so that the flow of the material in the casing 2 as the mixing tank is different in each rotation direction, and the mixing of the materials is performed. This is because the mixing time becomes faster and the final degree of mixing becomes better. Here, the rotation time and the stop time are not particularly limited, but it is preferable that the rotation time is equal to the clockwise direction and the counterclockwise direction, and the stop time may be shorter than the rotation time. Further, the shaft 8 has a relatively high speed (for example, 300 to 10,000 r.
pm), the hollow shaft 18 is relatively slow (eg 10-100
It is better to rotate at (rpm). In the mixer 1 of the present invention, the vicinity of the charging port 3 in the casing 2 (directly below the charging port when the charging port is provided in the upper part of the casing)
Is equipped with a crushing and dispersing means to crush and disperse the material M charged through the charging port 3, particularly the agglomerated powder or fine powder. As shown in FIG. 1, this crushing / dispersing means is composed of a rotor 27 attached to the tip of the shaft 8. As shown in FIG. 2, the rotor 27 has a structure in which a plurality of pin-shaped projections 272 are erected on a disc 271. The agglomerated powder or fine powder charged through the charging port 3 collides with the protrusions 272 of the rotor 27 which rotates at a high speed at the same time as the stirring blade 9 and is immediately crushed, and further dispersed by the centrifugal force in all directions. . The shape, number, dimensions (diameter, height), arrangement pattern, etc. of the protrusions 272 are not particularly limited, and these are the volume of the casing,
It may be appropriately set depending on the properties (particle size, specific gravity, etc.) of the material to be charged so that the crushing and dispersion efficiency is the best. In addition, in the mixer of the present invention, almost all powder and granules can be stirred and mixed. Examples thereof include powders such as wheat flour, starch, cement, tankar, alumina, and chemical powders, and salt, chemical seasonings, iron powder, sand, plastic grains, grains such as grains, and the like. Stirring 1 type or mixing 2 or more types. It can also be used for mixing the above materials with a liquid. In particular, the device of the present invention is suitable for powder or fine powder (particle size 10 μm
Suitable for agitation and mixing including (m or less). It is also suitable for mixing powders and granules that are easy to separate, mixing powders and granules having different specific gravities, and high-speed mixing of powders and trace components of powders. <Operation> The operation of the mixer of the present invention will be described below. The lid 6 of the discharge port 4 is closed, the lid 5 of the charging port 3 is opened, and one or more materials M are charged from the charging port 3. At this time, the motors 15 and 24 are driven to drive the stirring device 7
And the material scraping means (scraper 17) is activated. The charged material M, especially the powder in the agglomerated state, collides with the projections 272 of the rotor 27 rotating at a high speed and is immediately crushed, and further dispersed in all directions by centrifugal force. When non-aggregated granules are added, the granules are
Dispersed by. The powder and powder thus crushed and dispersed are stirred or mixed by the stirring blade 9 rotating at high speed. When the powders are mixed, they are already crushed and dispersed, so that high-speed and uniform mixing is possible. The material being mixed easily adheres to the inner wall 25 of the casing 2, but the scraper 17 that rotates (covers the entire inner wall).
This scrapes off the material adhering to the inner wall 25, preventing the material from accumulating. Further, the scraper 17 assists in the flow of the material and enhances the efficiency of stirring and mixing, especially when the scraper 17 is rotated in the reverse direction of the stirring blade 9. Since the inner shape of the casing 2 is spherical, there is no portion where the materials are mixed during the mixing, that is, there is no dead zone, so that uniform stirring and mixing of the materials can be performed in a short time. Especially,
Even when powders having different particle diameters and granules or powder granules having a large difference in specific gravity are mixed, they can be uniformly mixed in a short time. After the stirring and mixing of the materials are completed as described above, the motors 15 and 24 are stopped, the lid 6 is opened, and the stirred and mixed materials are collected from the discharge port 4. <Example> (Example of the present invention) Using a mixer having a structure shown in Fig. 1, the materials shown in Table 1 below were mixed in a batch manner under the following conditions. Inner diameter of casing: 200mmφ Stirrer: Stirrer blade: Plate blades with 3 stages Blade diameter: 120mm, 150mm, 100mm Rotation speed: 6000r.pm Scraper: Stainless steel ring (outer diameter 190mmφ) equipped with 4 urethane rubber members Rotation direction: Stirring blade and reverse rotation speed: 50r.pm Material crushing / dispersing means: Rotor: A disk with a diameter of 60mmφ, 33 pins of 10mm height are erected (comparative example) Conventional mixer As a Henschel type mixer,
The materials shown in Table 1 below were mixed. The mixing materials of the combination A and the combination B shown in Table 1 below were mixed using the mixers of the present invention example and the comparative example, and the change in mixing degree with time was examined. The results are shown in FIG. 4 (combination of A) and FIG. 5 (combination of B). In the combination A, the materials to be mixed have almost the same particle diameter and a difference in specific gravity. In the combination B, the particles to be mixed have a difference in particle diameter, and the alumina powder having an average particle diameter of 1 μm is
It is particularly easy to aggregate. The degree of mixing is calculated by the following formula (1). N: Number of sampling points Cj: Concentration at that point (sampling concentration) Co: Final concentration (calculated concentration) The closer M is to 0, the better the degree of mixing. As is clear from the graphs of FIGS. 4 and 5, the mixing degree of the mixer of the present invention is remarkably improved as compared with the conventional mixer. <Effects of the Invention> According to the mixer of the present invention, the inside of the casing is spherical, and the material scraping means for scraping off the material adhering to the inner wall of the casing and the crushing for crushing and dispersing the material put into the casing. By providing the dispersing means, the mixing degree of the materials is significantly improved. In particular, when mixing powders or fine powders that tend to agglomerate, the powders or fine powders fed in the agglomerated state are crushed and dispersed, and then mixed, so crushing means is provided separately Compared to conventional mixers that disintegrate simultaneously during body mixing,
The degree of mixing increases. As described above, the mixer of the present invention is used in a wide range of fields such as mixing of edible powders such as wheat flour and starch, mixing of chemicals, mixing of powders of inorganic products such as ceramics, mixing of resin particles, etc. because the mixing efficiency of the materials is high. It is possible and highly useful. Further, according to the present invention, the mixer itself can be downsized by installing the shaft of the stirring device for stirring and mixing the materials and the scraper for scraping the materials so as to rotate concentrically and independently of each other. You can

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial cross-sectional side view showing a configuration example of a mixer of the present invention. FIG. 2 is a plan view showing a constitutional example of crushing and dispersing means used in the mixer of the present invention. FIG. 3 is a partial cross-sectional side view schematically showing the structure of a conventional mixer (MGT mixer) having a crushing means. FIG. 4 and FIG. 5 are graphs showing the relationship between the mixing time and the mixing degree of each mixer of the present invention and the comparative example in the examples. DESCRIPTION OF SYMBOLS 1 ... Mixer, 2 ... Casing, 3 ... Input port, 4 ... Discharge port, 5, 6 ... Lid, 7 ... Stirring device, 8 ... Shaft, 9 ... Stirring blade, 10 …… Bearing, 11 …… Seal member, 12,14 …… Pulley, 13 …… Belt, 15 …… Motor, 16 …… Material scraping means, 17 …… Scraper, 171 …… Ring member, 172… … Elastic member, 18… Hollow shaft, 19… Bearing, 20… Sealing member, 21, 23… Pulley, 22… Belt, 24… Motor, 25… Inner wall, 26… Sleeve, 27… … Rotor, 271 …… disc, 272 …… projection, 28 …… mixer (MGT mixer), 29 …… casing, 30 …… crushing means, 301 …… multi-stage blade, M …… material

Claims (1)

(57) [Claims] A casing having a material input port and a discharge port and having a spherical interior, and a crushing / dispersing unit installed near the input port in the casing for crushing and dispersing the material input from the input port; A stirrer having a shaft, a stirring blade with multi-stage blades attached to the shaft, and a drive means for rotating the shaft, and stirring and mixing the materials crushed and dispersed by the crushing and dispersing means. A scraper that rotates along the inner wall of the casing, and a drive unit that rotates the scraper, and a material scraping unit that scrapes off the material adhering to the inner wall of the casing, the shaft and the scraper. A mixer that is installed concentrically with and independent of each other. 2. The mixer according to claim 1, wherein the crushing / dispersing means is a rotor attached to the tip of the shaft of the stirring device and provided with a plurality of projections. 3. The scraper has a ring shape and has an elastic member that comes into contact with the inner wall of the casing.
The mixer according to Item 2 or Item 2. 4. The mixer according to any one of claims 1 to 3, wherein the scraper is rotationally driven at a lower rotation speed than the shaft of the stirring device. 5. The rotation speed of the shaft of the stirring device is 300 to 10,
000 rpm, the rotation speed of the scraper is 10 ~ 100r
Mixing machine according to claim 4 which is pm.