JPH067913B2 - Stirring blade of high-speed rotary shear stirrer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a stirring blade of a high-speed rotary shearing type stirrer for atomizing and dispersing a solid substance in a liquid and emulsifying the solid substance.

[Prior Art] As a stirring blade for a high-speed rotary shear stirrer,
The low-viscosity stirring blade is roughly classified into a low-viscosity type of 0 CPS or less and a high-viscosity type of about 5,000 to 100,000 CPS.
The stirring blades for high viscosity shown in FIGS. 8 and 9 are shown in FIGS. 8 and 9, for example.

[Problems to be Solved by the Invention] In the above low-viscosity stirring blade, due to the shape of the blade, a wide range of cavitation a occurs on the back side of the blade during the shearing action of the processing fluid, as shown in FIG. As a result, bubbles are actively split in the fluid to disperse and emulsify solid particles, but on the other hand, due to the cavitation, the fluidity of high-viscosity fluid is adversely affected, and the discharge performance due to the rotation of the stirring blade is increased. However, the high-viscosity stirring blade is suitable for the fluidity of high-viscosity fluid due to the blade shape having a lead angle, but on the other hand, as shown in FIG. 8, the occurrence of cavitation a occurs. Therefore, there is a problem in that the dispersion and emulsification effects of particles are poor.

[Means for Solving the Problem] In view of the above, the present invention aims to increase the occurrence of cavitation in a high-viscosity stirring blade having a lead angle in a wide range, and in the outer periphery of a base having a shaft hole in the center, In the case where a plurality of blades are formed with a desired lead angle and the overall shape is frustoconical, a curved concave portion that intensively generates cavitation is formed from the tip of the back surface of each blade to the rotation direction upward. Is characterized by.

[Operation] The blade of the stirring blade according to the present invention has a blade 3 formed with a desired lead angle α as shown in FIG. Therefore, when the stirring blade is rotated, a wide range of cavitation a is generated with the curved concave portion 4 as an important point, and the bubbles are concentrated, so that the dispersion of solid particles in the treatment liquid and the emulsification action are significantly enhanced. Moreover, due to the lead angle α of the blade, the fluidity of the high-viscosity liquid becomes better than that of the conventional high-viscosity stirring blade.

[Embodiment] An embodiment of the stirring blade according to the present invention will be described with reference to Figs.

In the drawing, reference numeral 1 is a base having a shaft hole 2 in the center thereof, and a plurality of (four in the illustrated example) blades 3 are provided on the outer periphery thereof at a desired lead angle α, and each blade 3 has a blade 3 on the back surface in the rotational direction. A curved concave portion 4 is formed upward from the lower tip 3'of the blade, so that the lower tip side of each blade 3 gradually becomes thicker,
The cross-sectional area becomes a blade shape that gradually expands.

As shown in FIG. 4, the stirring blade configured as described above is fixed to the high-speed rotating shaft 5 at the central shaft hole 2 and is fixedly supported by the fixing stay 6 in the processing tank (not shown) in the stator 7. The processing liquid is caused to flow upward from below through the through hole 8 of the stator 7 as shown by the arrow in FIG. On the back surface of the curved concave portion 4, the concentration of air bubbles due to the pocket phenomenon causes the cavitation generation region to spread over a wide area with a focus on that portion, and the dispersion of particles and the emulsification action are remarkably enhanced.
Occurrence of cavitation a when the curved concave portion 4 is about 1/3 from the lower tip in the length direction of the blade 3 as shown in the figure with four blades set at around 30 ° and the peripheral speed of the blade tip is 15 m / sec or more. When the state is observed with a high-speed video camera, a cavitation phenomenon is observed over the entire back surface, focusing on the curved concave portion 4 of the blade 3, as illustrated in FIG. The area was much wider than the case of the low-viscosity stirring blade shown in the figure and the high-viscosity stirring blade shown in FIG.

The experimental results showing the comparison of the treatment effects of the dispersion and emulsion particles according to the present invention are shown below.

Fig. 10 is a comparison of the discharge performance of viscous liquids, Fig. 11 is a comparison when a mixed liquid of water, an emulsifier and liquid paraffin is treated under the same conditions as low-viscosity emulsification, and Fig. 12 is water for high-viscosity emulsification. FIG. 13 is a comparative graph in the case where a mixed solution of an emulsifier and kerosene is treated under the same conditions, and FIGS. 13 and 14 show the distribution state of the particle size in the emulsification treatment of kerosene according to the present invention and a conventional blade. It is a performance comparison chart.

[Advantages of the Invention] According to the present invention, in a stirring blade provided with a plurality of blades provided with a desired lead angle, the stirring blade is provided on the back surface of each blade from the lower end to the upper side with respect to the rotation direction of the stirring blade. Since the curved concave portion is formed, when the liquid is agitated, cavitation occurs due to the curved concave portion as an important point, and due to a wide range of cavitation over the entire back surface of the blade due to the pocket phenomenon due to the curved concave portion, the bubbles are dispersed. Not only the emulsifying action of the treatment liquid is significantly enhanced, but also the flow angle of the viscous liquid is good due to the lead angle of each blade, and it can be used as the stirring blade of a shearing type agitator for emulsification treatment of low viscosity or high viscosity liquid. In addition, it has an excellent effect that the use of a power source can be reduced by improving the stirring effect.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a stirring blade according to the present invention,
FIG. 2 is a side view, FIG. 3 is a side view of a blade showing a cavitation generation state, FIG. 4 is a cutaway side view showing a use state of the stirring blade of the present invention, FIG. 5 is a plan view thereof, and FIG. Is a side view of the low-viscosity stirring blade, FIG. 7 is the same plan view, FIG. 8 is a side view of the high-viscosity stirring blade, FIG. 9 is the same plan view, and FIGS. 7 shows an experimental graph comparing the performance of the prior art. 1 ... Base 2 ... Shaft hole 3 ... Blade root 3 '... Lower tip of blade 4 ... Curved recess a ... Cavitation

Claims (1)

[Claims] 1. A base having an axial hole in the center thereof, in which a plurality of blades are formed at a desired lead angle to form a frustoconical shape as a whole, from the tip of the back surface of each blade with respect to the rotation direction. A stirring blade for a high-speed rotary shearing type stirrer, characterized in that a curved concave portion that concentrates cavitation is formed over the upper portion.