JP2015073963A - Agitation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an agitation device which can smoothly perform the mixing when paste-like material and powder are dispersion-mixed to liquid-like body or shape retention property of a solid material is required.SOLUTION: An agitation device includes: an agitation container 3 of which a bottom part 9 is hemispherical and a barrel part 7 is cylindrical; an agitation shaft 13 which is inserted from an above part with respect to the agitation container 3, is obliquely arranged and can be agitation-driven; an annular outside stirrer 15 whose upper part is attached to a lower part of the agitation shaft 13 and is subjected to proximity arrangement along the bottom part 9; and agitation bars 27, 29 extended to a position offset from a rotation axis C in the rotation axis C direction from both side parts which interpose the rotation axis of the outside stirrer 15.

Description

  The present invention relates to a stirrer provided for stirring food materials.

  As a conventional stirring device, for example, there is a stirring device described in Patent Document 1. The structure of this stirrer is that an annular stirrer frame is fixed to the lower end of the slant shaft in the direction of the extension of the shaft center in a slant shaft stirrer inserted obliquely from above the container in a cylindrical container with a hemispherical bottom. The lower part of the frame is placed close to the bottom of the cylindrical container. In the stirrer frame, a plurality of round pipes, flat steel plates, and the like, which intersect with the extension line of the oblique axis, are installed at intervals. Furthermore, a plurality of scraping blades for scraping the tank wall (hemisphere) are attached to an annular stirrer frame.

  This stirring device can efficiently stir and mix an object to be stirred such as food at a low speed, and is widely used as a heating stirrer for food processing.

  However, there are the following problems.

  (1) When a paste-like material such as miso is mixed and dispersed in a liquid, if the paste has low fluidity (= hard), the dispersion becomes insufficient (= paste remains).

  (2) When dispersing and mixing paste-like materials, powders, etc., a part of the stirrer / stirring blade that has little relative motion with the liquid to be stirred (a part where dynamic contact with the liquid is weak, for example, rotation of the stirrer The part to be dispersed adheres to the part of the stirrer located on the shaft core, the part where the stirrer moves at right angles to the liquid, the part of the stirrer where the liquid flow does not come into direct contact, etc. , A part thereof remains without being dispersed and mixed.

  (3) When flour such as flour is dispersed in the liquid, the dispersion may be insufficient and lumps may be formed.

  (4) When mixing ingredients with poor fluidity, they may rotate with the stirrer and mixing between ingredients may be insufficient.

  (5) The required mixing may not be obtained when the material to be stirred is altered by high-speed stirring or when the shape retention of the solid is required. For example, when solid particles are dispersed in a liquid and the specific gravity of the solid particles is different from that of the liquid and has sedimentation or levitation, mixing that overcomes buoyancy and sedimentation force is necessary. In cases where the tip speed is limited, it is necessary to increase the mixing force without increasing the rotational speed.

JP-A-9-308574

  The problem to be solved is that when a paste-like material, powder, or the like is dispersed and mixed with a liquid material, and mixing is required when shape retention of the solid material is required.

  In the present invention, it is possible to disperse and mix paste-like materials, powders, and the like for a liquid material, and to smoothly perform mixing when shape retention of a solid material is required. A cylindrical stirring vessel, an agitation shaft that is inclined and inserted into the agitation vessel from above, and that can be driven for agitation. And a stir bar extending from at least one of both sides sandwiching the rotation axis of the stirrer to a position offset from the rotation axis in the direction of the rotation axis.

  Since the stirrer of the present invention has the above-described configuration, it is possible to smoothly disperse and mix paste-like materials, powders, and the like with respect to a liquid material, and to perform mixing when shape retention of a solid material is required.

FIG. 3 is a schematic view mainly showing a stirring unit with a part of the stirring device omitted. Example 1 It is a top view of a stirring part. Example 1

  Disperse and mix paste-like materials, powders, etc. for liquids, and to facilitate smooth mixing when shape retention of solids is required, stirrer and both sides sandwiching the rotating shaft core of this stirrer And a stirring bar extending from at least one of them to a position offset from the rotation axis in the direction of the rotation axis.

  FIG. 1 is a schematic view mainly showing the stirrer with a part of the stirrer omitted, and FIG. 2 is a top view of the stirrer. In FIG. 1, the agitation unit is mainly shown as a main part, and a drive motor and the like for driving the agitation shaft are omitted.

  As shown in FIG. 1 and FIG. 2, the stirring device 1 is a device that stirs food, for example, and includes a heating pot 3 as a stirring container and a stirring unit 5.

  The heating pot 3 has a structure in which a cylindrical body portion 7 and a hemispherical bottom portion 9 are integrally formed, and constitutes a cooking container for charging with ingredients and cooking. For example, a jacket may be provided in a closed cross section around the outer surface of the heating pot 3 on the bottom 9 side. Steam is heated and discharged from the outside to the jacket. The bottom portion 9 may be heated by electricity, electromagnetic waves, gas, or the like without providing a jacket. The heating structure can be omitted, and it can be configured as a simple cooking container. The heating pot 3 is supported on the base via, for example, legs.

  A lid is attached to the upper end of the heating pot 3 so that it can be opened and closed.

  The stirring unit 5 includes an outer stirring bar 15 and an inner stirring bar 17 as stirring bars attached to the stirring shaft 13.

  The stirring shaft 13 is inserted into the heating kettle 3 from the upper side and is inclined to be agitated and driven by a driving unit configured by an electric motor and a gear box (not shown) coupled to the upper end outside the heating kettle 3. Yes.

  The outer stirrer 15 is formed in a substantially annular shape by a round pipe, and the upper part is fixedly attached to the lower part of the stirring shaft 5. The lower part of the outer stirrer 15 is close to the bottom 9 of the heating kettle 3 and is disposed close to the bottom 9 so that the center of curvature of the outer stirrer 15 substantially coincides with the center of curvature of the bottom 9. The lower ends 15 a and 15 b of the outer stirrer 15 are spaced apart from each other, the lower end 15 a is disposed close to the rotational axis C of the stirring shaft 15, and the lower end 15 b is slightly separated from the rotational axis C. A temperature sensor 16 is attached to the tip of the lower end 15a so that the temperature on the rotation center side can be detected.

  The lower ends 15a and 15b are joined by an arch-shaped reinforcing portion 18. A first arm portion 21 is attached to the lower end 15a, and a second arm portion 23 is attached to the lower end 15b. The first and second arm portions 21 and 23 are formed in a curved shape so that the first arm portion 21 has no blind spot of the stirring action on the bottom side of the outer stirrer 15.

  A plurality of scraping blades 25 (only one is shown in the figure) are attached to the outer stirrer 15 at a predetermined position at a predetermined interval. The scraping blades 25... Scrape and slide the inner surface of the bottom 9 by the turning rotation of the outer stirrer 15 via the stirring shaft 13.

  The inner stirrer 17 is formed of a round pipe like the outer stirrer 15, and is arranged in a crossed manner inside the outer stirrer 15 so as to be integrally rotatable with the same rotation shaft, and is formed in a long annular shape in the direction of the rotation shaft C. Has been. The oval shape of the inner stirring bar 17 is close to an elliptical shape, and the upper part is coupled to the lower end part of the stirring shaft 13 and the lower end is coupled to the reinforcing part 18. The oval shape of the inner stirrer 17 is not limited to an elliptical shape, and various shapes such as a rectangle and a diamond can be selected depending on the purpose of stirring.

  A plurality of straight shearing bars 27 and 29 are provided in parallel as spaced apart from each other on both sides of the rotating shaft C as stirring bars for connecting the outer stirrer 15 and the inner stirrer 17. ing. With this connection, the shearing bars 27 and 29 are configured to extend from both side portions sandwiching the rotation axis of the stirrer toward the position offset from the rotation axis in the direction of the rotation axis. However, the stirring bar only needs to be extended from at least one of both sides sandwiching the rotation axis of the stirring bar, and only one of the shearing bars 27 and 29 may be provided. Further, the shape is not limited to a straight shape, and may be formed in a cross-sectional shape having a change such as a wave shape or a thick thin shape in the length direction.

  These shearing bars 27 and 29 are arranged stepwise in the rotational axis direction. Further, the shearing bars 27 and 29 are disposed slightly inclined so that the inner stirrer 17 side is lowered in the direction of the rotation axis C, and the outer stirrer 15 side that is higher in the rotation axis C direction during forward rotation. When the portion at the front is rotated, the ingredients and the like flow toward the bottom 9 of the heating pot 3, and at the time of reverse rotation, the portion on the inner stirrer 17 side, which is the lower side in the direction of the rotation axis C, is rotated. Then, the ingredients are agitated so as to tend to flow to the upper part of the heating pot 3.

  The stirrer 5 retains the mechanical strength as a stirring blade due to the coupling with the shearing bars 27 and 29.

  More specifically, the rotating shaft core C of the stirring unit 5 is in the extending direction of the drive shaft of the drive unit (not shown), and is set at an oblique angle with respect to the heating pot 3. It is inclined 20 ° to 40 °, preferably about 30 ° with respect to the vertical axis of the heating pot 3.

  The double ring of the outer stirrer 15 and the inner stirrer 17 is on the extension of the axis of the stirring shaft 13 whose oblique line is the oblique axis, and the crossing angle of the plane including each ring is set. As seen from the top surface in the direction of the rotation axis C, the crossing angle of the outer stirrer 15 and the inner stirrer 17 is about 60 ° to 150 °, preferably about 110 °. The inner stirrer 17 and the shearing bars 27 and 29 are arranged in an inverted Z shape on the inner diameter side of the outer stirrer 15 as shown in FIG.

  Although mentioned later, the reinforcement part 18 as a part which has connected the outer stirrer 15 and the inner stirrer 17 is not installed when the adhesion | attachment of a foodstuff, etc. to this site | part becomes a problem. The reinforcing portion 18 is easier to manufacture if it is manufactured.

  The width of the inner stirrer 17 is preferably about 30% or more of the diameter of the hemispherical portion of the bottom 9 of the heating pot 3 (70 to 20%). The shearing bars 27 and 29 are the center of the stirring function, and the inner stirring bar 17 can be partially or entirely omitted.

  The shearing bars 27 and 29 and the rotational axis C are spatially twisted by the arrangement and coupling structure as described above, but the mutual angle of the shearing bars 27 and 29 with respect to the plane perpendicular to the rotational axis C is Some sharp or obtuse angles.

  Since the outer stirrer 15 and the inner stirrer 17 are connected by shearing bars 27 and 29 at appropriate intervals, this angle changes from an acute angle (upper side) to an obtuse angle (lower side). Compared with the case where the angle is a right angle, the range of the movement (movement) trajectory of the shearing bars 27 and 29 is widened, and the mixing effect is slightly increased, which is preferable.

  That is, when the shearing bar is on a plane orthogonal to the rotation axis C, the rotation locus is on the orthogonal plane. On the other hand, in the case of having an angle with respect to the orthogonal plane, the rotation locus becomes the side surface of the truncated cone and spreads in the axial direction, contributing to mixing in the axial direction.

[Stirring function]
The problem could be improved / solved by the rotation of the stirring unit 5 of the stirring device 1. More preferably, the forward rotation and the reverse rotation of the stirring unit 5 are repeated at an appropriate frequency.

(1) Elimination of the mixing / adhesion problem on the stirring shaft As explained in the above-mentioned problem, if there is a center shaft or the like on the rotating shaft C having a low momentum in the rotational motion, the object to be stirred becomes entangled (attached) And poor mixing that is not dispersed in the liquid occurs. For example, in a conventional circle blade, an adhesion problem occurs at a portion where the shearing bar intersects the axis of the stirring shaft.

  The stirring device 1 of the embodiment of the present invention has no center shaft that is present in a normal stirring device, and there is no object such as a stirring blade in the position of the rotary shaft C, so that the problem is avoided.

(2) Elimination of adhesion problems where the relative motion with the liquid is low on the surface of the stirring blade
In the conventional circle blade, the shearing bar passes through the axis of rotation, and the fluid receives a force perpendicular to the surface of the shearing bar by the rotation. As a result, the fluid is given shear mixing by the shearing bar and a flow in the same direction as the rotation direction of the shearing bar.

  However, the surface of the shearing bar moves perpendicularly to the liquid, so there is no liquid flow around the surface and it is fixed to the bar. If a substance such as powder adheres to this part, it stays at that point and is not dispersed. Will occur.

  On the other hand, in the embodiment of the present invention, the axis of rotation does not intersect with the shearing bars 27 and 29, and the shearing bars 27 and 29 move at an angle rather than a right angle with respect to the fluid nearby, so that shearing Shapes the flow along the bar with mixing effects. A flow is generated in a predetermined direction on the surfaces of the sill bars 27 and 29, and adhesion to the portions is prevented.

(3) Mixability improvement In the case of a conventional circle blade, the shearing bar passes through the axis of rotation, and the fluid receives a force perpendicular to the surface of the shearing bar. As a result, the fluid is given shear mixing by the shearing bar and a flow in the same direction as the rotation direction of the shearing bar. The flow in the same direction as the rotation direction is a co-rotation with a so-called stirring unit, and is a flow with poor mixing in the fluid.

  On the other hand, the shearing bars 27 and 29 according to the embodiment of the present invention move with an angle rather than a right angle with respect to the fluid in the vicinity thereof, so that the shearing effect and the effect of shaping the flow in the direction along the bar are given.

  This is a very important effect that does not have the effect of shaping the flow in the direction along the bar. The effect of shear mixing by the shearing bars 27 and 29 is a mixing effect due to disturbance of the liquid flow in the vicinity of the bar, but most of the kinetic energy given to the fluid by the shearing bars 27 and 29 is lost by mixing.

  On the other hand, the flow directed by the shearing bars 27 and 29 has little loss of kinetic energy, and the influence reaches a position far away from the shearing bars 27 and 29.

  The mixing force of the heating pot 3 is indicated by the concept of a combination of local mixing and circulating mixing of the entire tank. That is, there is a local mixing force, and even if the mixing of the local part is strong, if the circulating flow in the tank is weak, the material replacement is weak and the intended mixing cannot be obtained.

  In addition to local partial mixing, stirring and mixing of substances that have sedimentation, poor fluidity, and high viscosity requires mixing by liquid flow across the entire tank, and the entire material in this tank is circulated as a whole. The effect is very effective.

  The mixing effect by this circulation can be adjusted by the angle and shape (flat plate, rod, channel surface area, length, etc.) with respect to the rotation (movement) direction of the shearing bar.

(4) Explanation of mixing by liquid circulation in the tank Since the stirring device 5 is installed obliquely in the tank, the stirring device 25 has a scraping blade 25 that revolves around the hemispherical portion of the bottom 9. While sliding on the vessel wall of the bottom portion 9, the vessel wall of the barrel portion 7, which is the straight barrel portion at the top of the tank, moves in the liquid. The stirring effect of the scraping blades 25... Will be described separately for the hemispherical part at the bottom of the tank of the heating pot 3 and the straight body part at the top of the tank.

  First, about the hemispherical part of the tank lower part, if the stirring part 5 is rotated, the to-be-stirred object in a tank wall surface will be scooped up by the scraping blade 25 ..., and will move to the outer side stirring element 15 inner side direction.

  In such a movement, the agitated material is torn by the shearing bars 27 and 29 together with the agitated material positioned on the swirling surfaces of the shearing bars 27 and 29 and subjected to shear mixing. , 29 and flows from the outer periphery of the tank toward the center.

  On the other hand, the back side of the outer stirrer 15 and the scraping blade 25... Sucks the surrounding stirring object by rotation, so that the flow toward the central part is scraped in a U-turn shape due to inertia. It flows toward the back side of the blades 25. In this way, an object to be stirred (rotational motion) in front of the scraping blades 25..., The outer stirrer 15, the shearing bars 27, 29, etc. passes through the outer stirrer 15 and the shearing bars 27, 29. After being mixed and oriented by, the direction gradually changes due to inertia, circulation from the center direction toward the back side of the scraping blade 25 ... of the tank wall occurs, and the agitated material in the tank flows to mix as a whole Is promoted.

  Next, the straight body part at the top of the tank will be described.

  When the scraping blades 25 are positioned in the body part 7 on the upper side of the tank, the space between the tank walls is open. The object to be stirred (fluid) in front of the blade rotation is pushed away by the rotation of the scraping blade 25... The shearing bars 27 and 29 are used for mixing and orientation.

  However, the amount of fluid is reduced and weaker than in the case of the bottom portion 9 with the tank wall, and both the flow inside and outside the ring of the outer stirrer 15 reverses as time passes and the inertia decreases and the scraping blade 25.・ Go to the back.

  Further, in this case, the scraping blade 25... Is different from the axis of the rotational movement and the axis of the tank geometric shape. Mixing at the receiving body 7 is promoted.

  As described above, stirring and mixing of a material with poor fluidity and a material with high viscosity requires mixing by the flow of the entire tank in addition to local partial mixing, and rotation of the scraping blade 25. The combination of the flow flowing through the entire tank directed by the shearing bars 27, 29 and the shear mixing by the shearing bars 27, 29 is a suitable mixing mechanism.

(5) Mixing / stirring effect by repeating periodic forward rotation and reverse rotation When the agitating unit 5 is temporarily stopped and then reversely rotated, the material flow direction and the movement direction of the scraping blades 25... The opposite direction. Changing the rotation direction gives a strong mixing effect to the material, gives stirring strength that cannot be obtained in a certain direction, and enables more uniform dispersion by dispersing the powder in the liquid.

  Furthermore, since the material flow direction changes greatly, mixing is accelerated and the mixing time is greatly shortened.

  In addition to the above effects, there are effects specific to this unit.

  By rotating in the reverse direction, the flow of the material is reversed, and the object to be stirred at the center flows into the wall surface of the heating kettle 3 along the shearing bars 27 and 29. This movement is further inclined by setting the rotation axis C of the agitating unit 5 at an angle, and three-dimensional agitation is achieved. By repeating the normal rotation and the reverse rotation at an appropriate frequency, extremely efficient mixing is achieved. This will save you work.

  (6) The rotating motion of the shearing bars 27 and 29 forms a slant (surface) with respect to the rotational axis C and performs a circular (circular) motion. Compared with shear stirring by counter flow with a conventional stirrer, the damage to the solid in the object to be stirred is extremely small and shape retention can be maintained. The change in physical properties of the solid matter due to stirring was eliminated.

(7) Inside of the inner stirrer The inside of the inner stirrer 17 is not only expected to have a mixing effect, even if a stirrer blade is installed. There is a risk that paste and other materials to be dispersed adhere. Therefore, the inside of the inner stirrer is a space, and flows (replaces) and mixes according to the liquid flow in the tank.

  The stirring effect by the rotational motion of the inner stirrer ring is useful because it has a shearing effect and a swirling effect on the material, but when the width of this ring is narrowed, the moving speed becomes slower as described above, and the stirring effect As it becomes smaller, there is a risk of adhesion and the like.

  Therefore, as described above, the width is limited and, in some cases, installation is not necessary.

(8) Crossing angle of inner and outer rings The shearing bars 27 and 29 connecting the rings of the outer stirrer 15 and the inner stirrer 17 are the lengths of the bars 27 and 29 with respect to the fluid between the outer and inner stirrers 15 and 17. Since it moves at an angle rather than at right angles to the direction, it has the effect of shaping the flow in the direction along the bars 27, 29 along with the shear mixing effect.

  However, as the rotational axis C approaches, the moving speed of the bars 27 and 29 is slow, the mixing force decreases, and there is a risk of adhesion, so the crossing angle of the outer stirrer 15 and the inner stirrer 17 is 180 as described above. Decided to exclude degrees. As the shearing bars 27 and 29 are longer, the effect is higher, so about 60 ° to 150 ° is appropriate.

  Such a stirring function improved / resolved the problem.

[Others]
The to-be-stirred thing which the stirring apparatus 1 stirs is applicable not only to a foodstuff but to what requires stirring, such as a medicine and a building material.

1 Stirrer 3 Heating kettle (stirring container)
5 Stirrer 7 Torso 9 Bottom 13 Stir Shaft 15 Outer Stir Bar (Stir Bar)
17 Inside stirrer (stirrer 27, 29 Shirring bar (stirring bar)
13 Stirring shaft

Claims (5)

A stirring vessel having a hemispherical bottom and a cylindrical barrel;
An agitation shaft that is inserted into the agitation vessel from above and is inclined and can be agitated,
An annular stirrer having an upper part attached to the lower part of the stirring shaft and disposed close to the bottom part, and
A stirring bar extending from at least one of both sides sandwiching the rotation axis of the stirrer to a position offset from the rotation axis in the direction of the rotation axis;
A stirrer comprising: The stirring device according to claim 1,
The annular stirrer is an outer stirrer,
A cross-arranged inner side of this outer stirrer is provided so as to be integrally rotatable with the same rotation axis, and has an elongated inner stirrer that is long in the direction of the rotation axis,
The stir bar connects between the outer stir bar and the inner stir bar,
A stirrer characterized by that. The stirring device according to claim 1 or 2,
A plurality of the stirring bars are provided at intervals.
A stirrer characterized by that. The stirring device according to claim 2 or 3,
The stirring bar is disposed so as to connect between the outer stirring bar and the inner stirring bar on both sides sandwiching the rotation axis;
The agitation bars on both sides sandwiching the rotational axis are arranged in steps in the rotational axis direction,
A stirrer characterized by that. The stirring device according to any one of claims 1 to 4,
A scraping blade for scraping the tank wall formed by the inner surface of the stirring vessel was attached to the stirring bar.
A stirrer characterized by that.

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