JP5062696B2 - Stirrer - Google Patents

Description

  The present invention relates to a liquid stirrer, and in particular, prevents separation of a flow pattern, performs good mixing in the entire stirring tank corresponding to a viscosity change during stirring and a wide viscosity range, and lowers the liquid depth. However, the present invention relates to a stirrer capable of stirring without changing the efficiency.

Conventionally, a stirrer for stirring treatment for the purpose of mixing and dissolving liquids is provided with a rotatable stirring shaft 2 at the center of a stirring tank 1 as shown in FIG. 2 is provided with a stirring blade 5.
The stirring blade 5 is a flat plate projecting in the radial direction from the stirring shaft 2, and a plurality of stages are provided on the stirring shaft 2 at intervals in the vertical direction.

  By the way, in this conventional stirrer, in order to widely stir the inside of the stirring tank 1, the flat stirring blades 5 are provided in a plurality of stages, but the lower stirring blade 5 rises at the side wall 11 of the stirring tank 1. On the other hand, since the upper stirring blade 5 forms an upward flow and a downward flow on the side wall 11 of the stirring tank 1, the upper stirring blade 5 is moved up and down by the collision of the upward flow of the lower stirring blade 5 and the downward flow of the upper stirring blade 5. A divided flow layer is generated.

  That is, only the lower stage of the stirring tank is stirred by the lower stirring blade, and only the upper stage of the stirring tank is stirred by the upper stirring blade, so that the flow pattern is separated by the upper and lower flow layers, and the entire stirring tank is There was a problem that good mixing was difficult to be performed.

  In view of the problems of the conventional stirrer described above, the present invention prevents separation of the flow pattern, performs good mixing in the entire stirring tank corresponding to the viscosity change during stirring and a wide viscosity range, and the liquid depth. An object of the present invention is to provide a stirrer that can stir without changing the efficiency even when the temperature becomes low.

In order to achieve the above object, the stirrer of the present invention is provided with a rotatable stirring shaft at the center of the stirring tank, and a stirring blade provided with a stirring blade on the stirring shaft. A bottom blade is provided that stirs the bottom and generates a circulating flow consisting of an upward flow along the side wall of the stirring tank and a downward flow that descends near the center of the stirring tank, and rotates above the bottom blade of the stirring shaft. An arm wing that shears a circulating flow by being configured with a square member having a corner portion directed in a direction is arranged so that a tip end side of the arm wing extends obliquely upward toward an outer peripheral side .

In this case, the position of the arm wing in the height direction relative to the stirring shaft can be adjusted .

  Further, the rotation diameter of the arm wing can be made equal to or less than the rotation diameter of the bottom wing.

  Moreover, the front-end | tip part of a bottom wing | blade can be bent diagonally in the direction after rotation.

  Further, the bottom blade can be formed in an arc shape that is convex in the rotational direction.

  Further, the bottom wing and the arm wing can be installed so as to have different rotational phases.

  Further, it is possible to install a plurality of stages of arm wings so that the rotational phases are different.

According to the stirrer of the present invention, mixing and stirring can be performed by the circulation flow generated by the bottom blade, and mixing and stirring can be performed by sequentially shearing the circulation flow by the arm blade, thereby allowing the conventional flow to flow. Even if the liquid depth is lowered by preventing the separation of the pattern, mixing well in the entire stirring tank corresponding to the viscosity change during stirring and a wide viscosity range, and shearing the circulating flow by the bottom blade Stirring can be performed without changing the efficiency.
And by configuring the arm wings with square members with the corners facing the rotation direction, it is possible to minimize the discharge from the arm wings and shear the circulating flow without hindering the upward flow from the bottom wings. In addition, it is possible to prevent liquid splashing on the liquid surface and prevent air entrainment.
Also, by placing the arm wing on the stirring shaft so that the tip end side of the arm wing extends obliquely upward toward the outer peripheral side, a long shear wing can be accommodated within a limited range to obtain a high shearing force. Can do.

Further , by making it possible to adjust the position of the arm wing in the height direction with respect to the stirring shaft, the arm wing can be adjusted according to the position of the liquid level and the like .

  Further, by setting the rotation diameter of the arm wing to be equal to or less than the rotation diameter of the bottom wing, the circulating flow can be sheared without hindering the upward flow from the bottom wing.

  Further, by bending the tip of the bottom blade obliquely in the direction after rotation, the discharge flow toward the side wall of the stirring tank can be increased and the circulation flow can be strengthened.

  In addition, by forming the bottom blade in a circular arc convex in the rotation direction, the discharge flow toward the side wall of the stirring tank can be increased and the circulation flow can be strengthened.

  Further, by arranging the bottom wing and the arm wing so as to have different rotational phases, it is possible to prevent the liquid from rotating together.

  In addition, by installing a plurality of stages of arm wings so that the rotational phases are different, the position to which the shear force is applied can be dispersed vertically and the co-rotation of the liquid can be prevented.

  Hereinafter, embodiments of the stirrer of the present invention will be described with reference to the drawings.

1 to 3 show an embodiment of the stirrer of the present invention.
In this stirrer, a rotatable stirring shaft 2 is disposed at the center of the stirring tank 1, and a stirring blade is provided on the stirring shaft 2.
And this stirrer stirs the bottom part of the stirring tank 1 in the lower part of the stirring shaft 2, and makes the circulating flow which consists of the upward flow along the side wall 11 of the stirring tank 1 and the downward flow descending near the center of the stirring tank 1 A flat bottom blade 3 to be generated is disposed, and a rod-shaped arm blade 4 that shears the circulating flow is disposed above the bottom blade 3 of the stirring shaft 2.

The stirring tank 1 has a bottomed cylindrical shape, and a stirring shaft 2 that is rotated by a motor (not shown) is disposed at the center.
Further, the stirring tank 1 can be provided with a thermal insulation or cooling jacket (not shown) around it, the side wall 11 and the bottom wall can be made transparent, and formed in various capacities of tens to hundreds of liters. Can do.

A flat bottom blade 3 is fixed to the lower part of the stirring shaft 2 by welding or boss connection so as to be close to the bottom wall 12 of the stirring tank 1.
The bottom blade 3 generates a discharge flow toward the side wall 11 of the agitation tank 1 due to the rotation thereof, and the upward flow that the discharge flow turns and the upward flow turns inward at the liquid level, and near the center of the agitation tank 1. A circulating flow consisting of a descending downward flow is generated.
The bottom blade 3 has a large rotation diameter that is about ½ of the inner diameter of the stirring tank 1, and generates a strong discharge flow with the large bottom blade 3, and the high viscosity of 10,000 cp or more from a low-viscosity liquid such as water. It can be used for liquids with a wide range of viscosity up to a liquid with a viscosity.

In this case, as shown in FIG. 5A, the bottom blade 3 bends its tip portion obliquely in the post-rotation direction, thereby increasing the discharge flow toward the side wall 11 of the agitation tank 1 and increasing the circulation flow. Can strengthen.
Here, bending the tip of the bottom blade 3 obliquely in the post-rotation direction means a state in which the bottom blade 3 extending in the radial direction is bent toward the opposite side of the rotation direction at the tip.
Moreover, as shown in FIG.5 (b), by forming the bottom wing | blade 3 in the circular arc convex to a rotation direction, a discharge flow can be similarly increased and a circulation flow can be strengthened.

On the other hand, above the bottom blade 3 of the stirring shaft 2, a rod-shaped arm blade 4 that shears the circulating flow is provided via a boss 41 as shown in FIGS. 1A and 3, or as shown in FIG. 2. It is fixed by direct welding.
In addition, as shown in FIG. 3, when connecting via the boss | hub 41, by fixing with the screw | thread 42, the fixing position of the arm wing | blade 4 can be adjusted according to the position of a liquid level, etc.
The arm wings 4 are symmetric and form one set, and in this embodiment, two sets of arm wings 4a and 4b are provided vertically.
The arm wing 4 has an angle of 0 degree to 90 degrees with respect to the stirring shaft 2, and in the present embodiment, the arm wing 4 is inclined from the horizontal projecting portion of 90 degrees as shown in FIG. It is designed to extend upward.
Although not particularly limited, in this embodiment, a plurality of arm wings 4 a and 4 b are provided as the arm wings 4 at the top and bottom, and the angle θ 1 of the upper arm wing 4 a with respect to the stirring shaft 2 is about The angle θ2 of the lower arm wing 4b is set to about 60 degrees at 30 degrees.
The arm wing 4 is set to have a rotation diameter equal to or less than the rotation diameter of the bottom wing 3 so as not to hinder the upward flow of the circulation flow. The long arm wings 4 are accommodated within the range so that a high shearing force can be obtained.
Further, Udetsubasa 4, as shown in FIG. 3, or not be provided with horizontal extending portion is constituted only by the horizontal overhang by an angle of 90 degrees with respect to the stirring shaft 2 (not shown) (Reference Example ) can also be.

Moreover, the arm wing 4 is comprised with the square material which orient | assigned the corner | angular part to the rotation direction.
As shown in FIGS. 2 to 3, the square member is formed of a solid or hollow triangular prism or quadrangular prism, and an acute corner is directed in the rotational direction so as to be symmetric with respect to the rotational surface of the arm wing 4. Installed.
In this way, by turning the corners of the arm wings 4 in the rotational direction, the discharge from the arm wings 4 is minimized, the circulating flow is sheared without hindering the upward flow from the bottom wings 3, and the liquid Liquid splash on the surface can be prevented, and air entrainment can be prevented.
Although not shown in the figure, the arm wings 4 can also be constituted by round bars in addition to square bars, and the arm wings 4 can be inclined obliquely downward with the tip side down ( Reference example) .
This round arm wing 4 also suppresses the discharge from the arm wing 4, reduces the inhibition of the upward flow from the bottom wing 3, shears the circulating flow, suppresses the liquid splash at the liquid level, Entrainment can be suppressed.
Further, as shown in FIGS. 4A to 4C, the arm wing 4 connects the upper and lower arm wings 4 and the bottom wing 3, the upper and lower arm wings 4, or the left and right arm wings 4 to each other. It can also be connected with.
The connecting member 43 can be composed of a rod, a flat plate, or a square member having a corner portion in the rotational direction, like the arm wing 4.

In this case, as shown in FIG. 6, the bottom wing 3 and the arm wing 4 are installed so as to have different rotational phases, thereby preventing the liquid from rotating together.
In addition, as shown in FIG. 7, by installing a plurality of stages of arm wings 4a and 4b so that the rotational phases are different, the position to which the shearing force is applied is dispersed vertically and the co-rotation of the liquid can be prevented. it can.

Next, the operation of the stirrer of this embodiment will be described.
When the liquid is put into the stirring tank 1 and the stirring shaft 2 is rotated, the discharge flow from the bottom blade 3 changes to an upward flow and reaches the liquid surface, and at the same time, a pull-in due to the rotation occurs and a downward flow is generated.
And the circulating flow which consists of an upflow and a downflow is sheared by 2 sets of arm wings 4a and 4b.
At that time, since the arm wings 4 are angled with respect to the rotation direction, the discharge from the arm wings 4 is suppressed, and the circulating flow can be sheared without hindering the upward flow from the bottom wings 3.

Using a jacketed 250 L stirring tank and a jacketed 100 L stirring tank, the heat transfer coefficient was measured with water and silicone oil.
Moreover, the power and mixing time measurement with water and a CMC viscous liquid were performed using a 30 L transparent stirring tank and a 300 L transparent stirring tank.
As a result, good test results could be obtained in all cases.
FIG. 8 is a graph showing the relationship between the mixing time and the power per unit volume, comparing the stirrer of this example with the conventional stirrer, and the stirrer of this example has better mixing efficiency than the conventional stirrer. Recognize.

Known stirring blades include paddle blades, turbine blades, anchor blades, ribbon blades, and the like. However, it is difficult to stir all of the stirring blades in a wide viscosity range or in response to changes in liquid depth.
On the other hand, in the stirrer of the present embodiment, stirring corresponding to a wide viscosity range and liquid depth change is possible by the shearing of the upward flow from the bottom blade 3 and the circulating flow by the arm blade 4.

  Thus, the stirrer of the present embodiment is provided with a rotatable stirring shaft 2 at the center of the stirring tank 1, and the stirring tank 2 is provided with a stirring blade. A bottom plate 3 having a plate-like shape and generating a circulating flow consisting of an upward flow along the side wall 11 of the stirring tank 1 and a downward flow descending near the center of the stirring tank 1, and a stirring shaft 2 is disposed above the bottom blade 3 so as to shear and circulate the flow, so that mixing and agitation is performed by the circulation generated by the bottom blade 3, and the arm blade 4 Mixing and stirring can be performed with sequential shearing, which prevents separation of the flow pattern as in the past, and provides good mixing throughout the stirring tank in response to changes in viscosity during stirring and a wide viscosity range. At the same time, shearing the circulating flow by the bottom blade 3 Ri can be a stirring even when low liquid depth unchanged efficiency.

  In this case, by configuring the arm wing 4 with a square member whose corners are directed in the rotational direction, the discharge from the arm wing 4 is minimized, and the circulating flow is prevented without hindering the upward flow from the bottom wing 3. It is possible to shear, and furthermore, it is possible to prevent liquid splashing at the liquid level and prevent air entrainment.

  Further, by setting the rotation diameter of the arm wing 4 to be equal to or less than the rotation diameter of the bottom wing 3, the circulating flow can be sheared without hindering the upward flow from the bottom wing 3.

  Further, by bending the tip of the bottom blade 3 obliquely in the direction after rotation, the discharge flow toward the side wall 11 of the stirring tank 1 can be increased and the circulation flow can be strengthened.

  Further, by forming the bottom blade 3 in an arc shape that is convex in the rotation direction, the discharge flow toward the side wall 11 of the stirring tank 1 can be increased and the circulation flow can be strengthened.

  Further, by arranging the bottom wing 3 and the arm wing 4 so as to have different rotational phases, it is possible to prevent the liquid from rotating together.

  Further, by installing the plurality of stages of the arm wings 4a and 4b so that the rotational phases are different, the position where the shear force is applied can be dispersed vertically and the co-rotation of the liquid can be prevented.

  As mentioned above, although the stirrer of this invention was demonstrated based on the Example, this invention is not limited to the structure described in the said Example, The structure is changed suitably in the range which does not deviate from the meaning. Can do.

  The stirrer of the present invention prevents separation of the flow pattern, performs good mixing in the entire stirring tank corresponding to the viscosity change during stirring and a wide viscosity range, and the efficiency does not change even when the liquid depth decreases. Since it has the characteristic of stirring, it can be widely used as a stirrer suitable for, for example, stirring medium-high viscosity products in foods and stirring for multi-product small-quantity production.

(A) is sectional drawing which shows one Example of the stirrer of this invention, (b) is sectional drawing which shows a prior art example. The stirring axis | shaft of the stirrer of this invention is shown, (a) is the 3rd figure, (b) is an enlarged front view which shows an upper arm wing, (c) is an enlarged front view which shows a lower arm wing, (d) FIG. 3 is a cross-sectional view of an arm wing. The other Example of a stirring shaft is shown, (a) is the front view, (b) is the same side view. (A)-(c) is a front view which shows the further another Example of a stirring shaft. (A)-(b) is a top view which shows the other Example of a bottom wing | blade. The Example which made the rotational phase of a bottom wing | blade and an arm wing | blade different is shown, (a) is the top view, (b) is the B arrow view of (a), (c) is the C arrow view of (a). FIG. The Example which made the rotation phase of the arm wing | blade of several steps differ is shown, (a) is the top view, (b) is B arrow view of (a), (c) is C arrow view of (a). FIG. It is a graph which shows the relationship between the mixing time and the power per unit volume which compared the stirrer of a present Example with the conventional stirrer.

DESCRIPTION OF SYMBOLS 1 Stirring tank 11 Side wall 12 Bottom wall 2 Stirring shaft 3 Bottom wing 4 Arm wing 43 Connecting member

Claims (7)

In a stirrer provided with a rotatable stirring shaft at the center of the stirring tank and provided with a stirring blade on the stirring shaft, the bottom of the stirring tank is stirred at the bottom of the stirring shaft, and the upward flow along the side wall of the stirring tank And a bottom blade that generates a circulating flow consisting of a downward flow that descends in the vicinity of the center of the agitation tank, and is composed of a square member having a corner portion in the rotational direction above the bottom blade of the agitation shaft. An agitator characterized in that an arm wing for shearing a circulating flow is disposed so that a tip end side of the arm wing extends obliquely upward toward an outer peripheral side . The stirrer according to claim 1 , wherein the position of the arm wing in the height direction relative to the stirring shaft can be adjusted .   The stirrer according to claim 1 or 2, wherein the rotation diameter of the arm wing is set to be equal to or less than the rotation diameter of the bottom wing.   The stirrer according to claim 1, 2, or 3, wherein the tip of the bottom blade is bent obliquely in the direction after rotation.   The stirrer according to claim 1, 2, 3 or 4, wherein the bottom blade is formed in an arc shape convex in the rotation direction.   The stirrer according to claim 1, 2, 3, 4 or 5, wherein the bottom wing and the arm wing are installed so as to have different rotational phases.   The stirrer according to claim 1, 2, 3, 4, 5 or 6, wherein a plurality of stages of arm blades are installed so as to have different rotational phases.

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