JP2837029B2 - Stirring blade - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large-size stirring blade used for stirring an object to be stirred (mainly a liquid mixture) which varies greatly from a low viscosity (1 centipoise) to a high viscosity (tens of thousands of centipoise). It is about.

[0002]

2. Description of the Related Art Conventionally, as this type of agitating blade, for example, there is one shown in FIGS. That is, FIG. 12 shows a large paddle type stirring blade 41, and a paddle type blade plate 44 occupying almost the entire vertical cross section of the stirring tank 43 is attached to the rotating shaft. FIG. 13 shows an anchor type stirring blade 45,
An anchor-shaped wing plate 46 is attached to the lower end of the rotating shaft 42 inserted into the stirring tank 43. FIG. 14 shows a gate type stirring blade 47, and a rotating shaft 42 inserted into a stirring tank 43.
A wing plate 48 having a gate shape is attached to the wing. further,
FIG. 15 shows a helical ribbon type stirring blade 49, which has a spiral blade plate.
50 is attached to the rotating shaft 42 via the attachment arm 51. Each of the rotating shafts 42 is rotated by an electric motor 52.

According to these stirring blades 41, 45, 47 and 49,
By rotating the rotation shaft 42, each blade 44, 46, 48, 50
Rotates together with the rotating shaft 42, and the body to be stirred (mainly the liquid mixture) in the stirring tank 43 is stirred.

[0004]

However, according to the above-mentioned conventional type, as shown in FIGS. 13 to 15, the anchor-type stirring blade 45, the gate-type stirring blade 47 and the helical ribbon-type stirring blade 49 are not rotated. In this case, there are hollow portions 54 through which the blades 46, 48, and 50 do not pass, respectively, so that the stirrer in these hollow portions 54 is hardly sufficiently stirred, and the stirrer in the stirring tank 43 is uniformly stirred as a whole. There is a problem that it takes a long time to do so.

On the other hand, as shown in FIG. 12, a large paddle-type stirring blade 41 is provided with a paddle-type blade 44 occupying almost the entire vertical cross section of a stirring tank 43.
Although there is almost no hollow part as described above, since the blades 44 are mounted perpendicular to the rotation direction 55, the resistance during rotation is extremely large, and stirring is performed when the rotating shaft 42 is rotated by the electric motor 52. There is a problem that power (horsepower of the electric motor 52 required for stirring) increases.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a stirring blade capable of performing uniform stirring in a short period of time and reducing stirring power required for stirring.

[0007]

In order to solve the above-mentioned problem, a stirring blade according to the present invention comprises a first blade and a second blade which are rotatable about a rotation axis passing through a stirring tank. A driving device that displaces the second blade in the rotational direction with respect to the first blade and rotates the first blade and the second blade;
A plurality of the first blades and the second blades are particularly arranged at a predetermined pitch in the longitudinal direction of the rotation axis, and the second blades are attached to the first blades while being shifted by a half pitch. , the first vane and the second vane is inclined with respect to the rotation direction, the first
The vertical spacing of the blades is formed to be less than the vertical length of the second blade .

[0008]

According to the above construction, since the first blade and the second blade are each inclined with respect to the rotation direction, the resistance at the time of rotation is reduced, and the first blade and the second blade are rotated. The agitation power of the driving device required for this may be low.

Further, the second blade is shifted by a half pitch with respect to the first blade, and the vertical interval of the first blade is set to the second pitch.
Since the blades are formed to be shorter than the vertical length of the blades, the second blades pass through the hollow space between the upper and lower sides of the first blades over the entire range during rotation of the blades. The stirrer is sufficiently stirred by the first blades and the second blades so that uniform stirring can be performed as a whole in a short time.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, reference numeral 1 denotes a vertically arranged cylindrical stirring tank, and an upper portion of the stirring tank 1 is covered with a cover plate 2. A rotating shaft 4 that is rotatable around a vertical rotation axis 3 is inserted through the center of the stirring tank 1. The upper end of the rotating shaft 4 projects above the cover plate 2 and is connected to a motor 5 (an example of a driving device) provided on the cover plate 2 side.

The stirring tank 1 is provided with a stirring blade 7 for stirring the object to be stirred (mainly a liquid mixture). The stirring blade 7 has a cylindrical mounting boss 8 fitted and fixed to the rotary shaft 4 and a blade having one end mounted on a side surface of the mounting boss 8 and the other end extending outward of the rotary shaft 4. Plates 9 and 10 are provided.

As shown in FIGS. 2 and 3, these blades 9 and
A plurality of the blades 10 are attached to each other.
Are 0 ° in the circumferential direction of the mounting boss 8 and 1 in the plan view.
A plurality of sheets (four sheets in FIG. 3) are arranged at a predetermined pitch P in the vertical direction at two positions at an 80 ° position. Similarly, the second wing plate 10 is displaced at two positions of the mounting boss 8 at the 90 ° position and the 270 ° position in a plan view, and a plurality of sheets (in FIG. ) Are arranged. These second blades 10 are attached to the first blade 9 so as to be vertically displaced by a half pitch (P / 2), whereby the second blade 10 is vertically moved above and below the first blade 9. It can pass through the hollow space 11. Each first blade 9 and second blade 10
Has a rectangular plate shape in cross section, and is mounted in a forwardly inclined posture (inclination angle α = about 45 °) with respect to the rotation direction 12. Further, as shown in FIG.
Or the vertical spacing of the second blade 10) is La,
When the vertical length of 10 (or the first wing plate 9) is Lb, La
≦ Lb.

The operation of the above configuration will be described below.
By operating the electric motor 5, the stirring blade 7 rotates together with the rotating shaft 4. Thereby, the first wing plate 9 and the second wing plate 9
The vane plate 10 stirs the object to be stirred (mainly a liquid mixture) in the stirring tank 1. At this time, since the first blade 9 and the second blade 10 are each inclined forward with respect to the rotation direction 12, the resistance at the time of rotation is reduced, and the electric motor 5 required to rotate the rotary shaft 4 is rotated.
May have low stirring power (horsepower). Therefore, the power consumption of the electric motor 5 can be reduced, which is economical.

Further, the second blade 10 is shifted from the first blade 9 by a half pitch (P / 2) , and the first blade 9 is further shifted .
(Or the vertical spacing La of the second blade 10) ≦ the second blade 10 (or
Or the upper and lower lengths Lb of the first blade 9).
During the rotation of the stirring blade 7, since the second blades 10 pass through the entire space between the upper and lower hollow portions 11 between the first blades 9, the object to be stirred in the stirring tank 1 is the 1st wing plate 9 and 2nd wing plate 10
Thus, the mixture is sufficiently stirred, so that the whole can be uniformly stirred in a short time.

Hereinafter, test results of dispersion characteristics and mixing characteristics of the stirring blade 7 of the first embodiment and the conventional anchor-type stirring blade 45 shown in FIG. 13 will be described with reference to a characteristic graph shown in FIG. That is, the vertical axis of the characteristic graph shows the average diameter d of the dispersed droplets obtained by the wax method and the mixing time t obtained by the electric conductivity method, and the horizontal axis shows the stirring power P per the internal volume V of the stirring tank 1. The ratio (= P / V) is shown.

The stirring power P corresponds to the horsepower required for the electric motors 5, 52 to rotate the stirring blades 7, 45. The above-mentioned wax method means that wax is put into stirring tanks 1 and 43 filled with hot water and is stirred in a molten state. This is a method in which the dispersed droplets of the dispersed wax are solidified by cooling at a temperature of, and the diameter of the solidified wax particles is measured. Accordingly, in the relationship between the average diameter d of the particles and the P / V ratio, when the P / V ratio has the same value, the smaller the average diameter d, the better the dispersion characteristics.

Further, the electric conductivity method will be described below. That is, as shown in FIG. 1, upper and lower sensors 15 and
16 and the inside of the stirring tank 1 is filled with water. Thereafter, when the stirring blade 7 is rotated and a saline solution is injected from the upper portion of the stirring tank 1, the electrical resistance value detected by the upper sensor 15 becomes smaller than that of the lower sensor 16 due to the saline solution. Then, as the stirring progresses, the saline solution in the stirring tank 1 is uniformly mixed, and the electric resistance values of the upper sensor 15 and the lower sensor 16 become equal. By defining the time required from the injection of the saline solution to the equalization of the electric resistance value as the mixing time t, in the relationship between the mixing time t and the P / V ratio, the P / V ratio has the same value. In some cases, the shorter the mixing time t, the better the mixing characteristics.

According to the characteristic graph of FIG. 4, assuming that the vertical axis is the average diameter d, when the P / V ratio of the first embodiment is the same as that of the conventional example (A), Example stirring blade
In the case of 45, the average diameter d becomes (b) as shown by the two-dot chain line A, whereas in the stirring blade 7 of the first embodiment, the average diameter d becomes (c) as shown by the solid line B. Here, since b> c, if the internal volume V of the stirring tank 43 of the conventional example and the internal volume V of the stirring tank 1 of the first embodiment are the same, the mixing is performed even if the stirring power P is the same. It can be seen that the stirring blade 7 of the first embodiment has better dispersion characteristics. To explain this in another way, when the average diameter d is a constant value (b), the stirring blade 7 of the first embodiment can stir with lower stirring power (d) than the conventional one. Therefore, the stirring blade 7 of the first embodiment can perform stirring with lower horsepower and excellent dispersion characteristics than the conventional one.

When the ordinate represents the mixing time t, P / V
When the ratio is the same (a) between the first embodiment and the conventional example, the two-dot chain line A in the conventional stirring blade 45 is used.
, The mixing time t becomes (b), whereas the mixing time t of the stirring blade 7 of the first embodiment becomes (c) as shown by the solid line B. Here, since b> c, if the internal volume V of the stirring tank 43 of the conventional example and the internal volume V of the stirring tank 1 of the first embodiment are the same, the mixing is performed even if the stirring power P is the same. It can be seen that the stirring blade 7 of the first embodiment has better mixing characteristics. To explain this in another way, when the mixing time t is a constant value (b), the stirring blade 7 of the first embodiment can stir with smaller stirring power (d) than the conventional one. Therefore, the stirring blade 7 of the first embodiment can perform stirring with lower horsepower and excellent mixing characteristics than the conventional stirring blade.

Further, the characteristic graph shown in FIG. 4 is schematic, and more specifically, a graph showing the relationship between the average diameter d and the P / V ratio and a graph showing the relationship between the mixing time t and the P / V ratio. Are not the same but are slightly different.

In the above embodiment, as shown in FIG. 3, the inclination angle α of each of the first blades 9 and the second blades 10 is set to about 45 °. When the inclination angle α is 45 ° or more, the mixing characteristics are improved. Therefore, the dispersion and mixing characteristics can be arbitrarily controlled by variously selecting the inclination angle α.

In the above embodiment, the first blade 9 and the second blade 10
And four in the up-down direction and a total of four places in the circumferential direction of the mounting boss 8, but are not limited to four pieces × four places, and the depth of the body to be stirred in the stirring tank 1 is not limited to four. It is sufficient to dispose them on a plurality of sheets × a plurality of places according to the size.

Next, a second embodiment of the present invention will be described. That is, as shown in FIG. 1, each of the first
A reinforcing beam is provided between the other end portions of the wing plate 9 and the second wing plate 10.
Connected with 18 (pipe etc.). According to this, even if the entire length of each of the first blades 9 and the second blades 10 is long, the space between the other ends of the blades 9 and 10 is sufficiently reinforced, and each of the first blades 9 and 10 is rotated during rotation.
The other end portions of the wing plate 9 and the second wing plate 10 can be prevented from bending in the vertical direction.

Next, a third embodiment of the present invention will be described with reference to FIG. That is, each of the first blade 20 and the second blade 21
Has a streamlined cross section. According to this, when the first wing plate 20 and the second wing plate 21 rotate in the body to be agitated, it is more streamlined to make the cross-sectional shape more rectangular than to the rectangular shape (see the first embodiment). The resistance acting on 21 can be further reduced.

Next, a fourth embodiment of the present invention will be described with reference to FIGS. That is, each of the first blades 23 and the second
The blades 24 are mounted on the mounting bosses 8 by being shifted from the upper ones by a predetermined angle β in the rotation direction 12.

Next, a fifth embodiment of the present invention will be described with reference to FIGS. That is, an upper rotation shaft 4a and a lower rotation shaft 4b rotatable about the rotation axis 3 are provided,
A cross-shaped upper crossbar 26 is provided at the lower end of the upper rotating shaft 4a in plan view, and a cross-shaped lower crossbar 27 is provided at the upper end of the lower rotating shaft 4b. And the upper crossbar 26
Support pipe 28a between each end of the lower crossbar 27
2828d. Each of the first blades 29 is supported between a pair of support pipes 28a and 28c opposed to each other via the rotation axis 3, and a plurality of the first blades 29 are vertically mounted. Similarly, each of the second blades 30 is supported between a pair of support pipes 28 b and 28 d opposed to each other via the rotation axis 3, and is attached to an intermediate portion between the first blades 29. Accordingly, a stirring blade that can eliminate the need for the rotation shaft in the intermediate portion is configured.

Next, a sixth embodiment of the present invention will be described with reference to FIG. That is, the first blade 32 and the second blade 33
Is composed of a support beam 34 attached to the mounting boss 8 and a blade 35 attached to the tip of the support beam 34. Each blade 35 is mounted in a forwardly inclined posture with respect to the rotation direction 12, and the upper and lower ends of each blade 35 are supported by a support pipe 36.

[0028]

As described above, according to the present invention, by inclining the first blade and the second blade with respect to the rotation direction, the resistance at the time of rotation is reduced, and the first blade and the second blade are connected to each other. The stirring power of the driving device required to rotate the two blades may be low. Therefore, stirring with good power and low dispersibility can be performed, which is economical.

Further, the second blade is shifted by a half pitch with respect to the first blade, and the vertical interval of the first blade is set to the second pitch.
Since the blades are formed to be shorter than the vertical length of the blades, the second blades pass through the hollow space between the upper and lower sides of the first blades over the entire range during rotation of the blades. The stirrer is sufficiently stirred by the first blades and the second blades so that uniform stirring can be performed as a whole in a short time.

[Brief description of the drawings]

FIG. 1 is a side view of a stirring blade according to a first embodiment of the present invention.

FIG. 2 is a plan view of the stirring blade.

FIG. 3 is a side view showing a positional relationship between a first blade and a second blade of the stirring blade.

FIG. 4 is a graph showing dispersion characteristics and mixing characteristics of the stirring blade in the first embodiment of the present invention and the stirring blade in the conventional example.

FIG. 5 is a partially enlarged side view of a stirring blade according to a third embodiment of the present invention.

FIG. 6 is a plan view of a stirring blade according to a fourth embodiment of the present invention.

FIG. 7 is a side view of the stirring blade.

FIG. 8 is a side view of a stirring blade according to a fifth embodiment of the present invention.

FIG. 9 is a view on arrow AA in FIG. 8;

FIG. 10 is a view taken in the direction of arrows BB in FIG. 8;

FIG. 11 is a side view of a stirring blade according to a sixth embodiment of the present invention.

FIG. 12 is a side view of a stirring blade in a conventional example.

FIG. 13 is a side view of the stirring blade.

FIG. 14 is a side view of the stirring blade.

FIG. 15 is a side view of the stirring blade.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stirring tank 3 Rotation axis 5 Electric motor (drive device) 7 Stirring blade 9 1st wing plate 10 2nd wing plate 12 Rotation direction 20 1st wing plate 21 2nd wing plate 23 1st wing plate 24 2nd wing plate 29 First blade 30 Second blade 32 First blade 33 Second blade P Predetermined pitch

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masayuki Isaka 5-3-28 Nishikujo, Konohana-ku, Osaka-shi, Japan Hitachi Zosen Corporation (56) References JP-A-62-186929 (JP, A) 57-145536 (JP, U) Japanese Patent Publication 51-33298 (JP, B2) Japanese Patent Publication 55-26806 (JP, B2) Japanese Utility Model 54-255255 (JP, Y2) (58) Int.Cl. ⁶ , DB name) B01F 7/00-7/32

Claims (1)

(57) [Claims] A first blade and a second blade that are rotatable about a rotation axis passing through a stirring tank are provided, and the second blade is displaced in a rotational direction with respect to the first blade. A driving device for rotating the first and second blades is provided, and a plurality of the first and second blades are arranged at a predetermined pitch in the longitudinal direction of the rotation axis. Then, these second blades are attached to the first blade at a half-pitch offset, the first blade and the second blade are inclined with respect to the rotation direction, and the upper and lower portions of the first blade are vertically moved.
A stirring blade, wherein the gap is formed to be shorter than the vertical length of the second blade.