JPS60238128A - Stirring apparatus - Google Patents

Abstract

PURPOSE:To enhance recirculation function and to uniformize shearing speed distibution, by providing a spiral strip shaped stirring blade connected to the rotary shaft concentric to a container main body between the outer peripheral surface of the container main body. CONSTITUTION:When a rotary shaft is rotated to the direction shown by the arrow, the liquid held between a draft tube 8 and a main body container 1 is pushed up to the upper part by a spiral strip blade 10 and further flowed down through the draft tube 8 from the upper part thereof toward the lower part thereof to be again returned to the outside of the draft tube 8. By this recirculation, the liquid is locally mixed at first while receiving shearing action by the spiral strip blade 10 and subsequently also receives shearing action by guide plates 11, 12 in the draft tube 8 and is advancing while receiving local mixing and changes in its mutual position by the twist of said guide plates 11, 12.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stirring device used for stirring and mixing liquid substances to obtain a homogeneous product, and for reactions for producing a polymer compound under stirring conditions.

Many types of stirring devices have been used in the past; propellers, turbines, and paddles are common for low-viscosity liquids, while helical ribbon blades, screw blades, and anchor-shaped blades are common for high-viscosity liquids. It is true.

In particular, the mixing time of high viscosity liquids, which are often handled in the polymer manufacturing process, is extremely slow compared to low viscosity liquids, so the quality of the product is affected by the selection of stirring equipment, and care must be taken. . However, in the case of high viscosity liquids, the stirring power is large, so it is important to select an efficient mixing and stirring device from the viewpoint of power saving.

In terms of mixing efficiency, what functions are desired in a stirring device?

■ A function to flow the liquid throughout the tank (circulation function) ■ A function to evenly distribute the shear rate throughout the tank (uniform shear rate distribution function) ■ A function to promote macroscopic exchange of the liquid (liquid replacement function) function).

Therefore, when comparing the above eight functions with a typical conventional stirring device for high viscosity, the spiral band blade satisfies the function (■) above, but the function (■) is small, and the function (■) is moderate. In addition, the screw blade with draft tube is almost the same as the spiral band blade, and furthermore, the anchor type blade does not satisfy any of the functions (1) to (3) above.

As described above, until now, there have been almost no devices that can efficiently mix high viscosity liquids. The present invention proposes a novel stirring device that satisfies the above three functions.

The correspondence between the device shape of the present invention and the above functions is as follows.

(1) In order to further strengthen the strong circulation function of the spiral band blades, a spiral band blade is installed between the draft tube and the tank wall. As a result, compared to the case without a draft tube, the
The circulation performance is increased by 2.0 times, and the circulation function is fully satisfied.

(2) By installing a screw-shaped fluid guide plate inside the draft tube, the shear rate of the liquid passing through the draft tube can be increased, and the function of making the shear rate distribution uniform can be reinforced. .

(3) Furthermore, by shifting and inserting the fluid guide plates one after another, the location of the fluid passing through them can be changed, and the liquid replacement function is satisfied.

Hereinafter, nine embodiments of the present invention will be described based on FIGS. 1 and 2.

In the figure, the container body 1. Each lid 2 has a liquid supply port 3.
A discharge port 4 is provided, and a rotating shaft 5 is inserted from the top. A horizontally arranged arm 6 is connected to the rotating shaft 5, and support rods 7 are attached downward from both ends of the arm 6. A draft tube 8 is fixed to the container body 1 by a plurality of legs 9 so as to be concentric with the container body 1, and fluid can pass between the legs. A helical band blade 1° is installed between the draft tube 8 and the inner wall of the main body container 1, and since this is connected to the support rod 7, the helical band blade 10 rotates with the rotation of the rotation shaft 5. In addition, fluid guide plates 11 and 12 in the shape of twisted rectangular plates are fixedly installed in the draft tube 8, and the guide plates 11 and 12 are installed at a 90° offset as shown in the figure. ing.

According to this embodiment configured in this manner, when the spiral band blade 10 rotates in the direction of the arrow, the liquid held in the gap between the draft tube 8 and the main container 1 is directed upward. Pushed up.

Furthermore, it flows down from the upper part inside the draft tube 8 toward the lower part, and returns to the outside of the draft tube 8 again.

Through this circulation, the liquid is first locally mixed while being sheared by the spiral band blades 10, and then the draft tube 8.
The guide plates 11 and 12 inside the liquid are also sheared and mixed locally, and the liquid moves forward while changing its position with respect to each other by twisting the guide plates 11 and 12.

As explained above, in this embodiment, it is possible to achieve very rational mixing of liquids, and the effects of this embodiment will be explained in more detail with the following specific examples.

[Example 1] An experimental device was used in which a helical band blade with a blade diameter of 294 + mn, a blade width of 80 mm, and a helical pitch of 800 + n + n + height of 450 M was installed in a cylindrical container made of transparent acrylic with an inner diameter of 800 mm and a height of 550 M.

It has a viscosity of 120 Whis in the container, I2 and Na2S2
After dissolving 0g of each and supplying the two liquids, the stirring blade was
By rotating at rpm and measuring the number of revolutions until the brown color of I2 was decolored by N52S203, the number of revolutions N required to complete mixing was determined.

In the case of this device, the rotation was N-35.

[Specific Example 2] The device of the above specific example 1 has an outer diameter of 225 mm, an inner diameter of 200 mm,
A draft tube with a height of 450 m and two guide plates with a height of 225 m were installed as shown in Figure 1.

The number of rotations N required to complete mixing was determined under the same conditions as in Example 1, and was found to be N=26 rotations.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of main parts showing an embodiment of the present invention. FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1. 1. Container body, 8. Draft tube, 10.
...Spiral band blade, 11.12...Fluid guide plate. 2nd paper note 1

Claims (1)

[Claims] A cylindrical draft tube is provided in the cylindrical container body concentrically with the container body, and connected to a rotating shaft concentric with the container body between the outer circumferential surface of the draft tube and the inner circumferential surface of the container body. What is claimed is: 1. A stirring device characterized in that a stirring blade in the form of a spiral band is provided, and a fluid guide plate which is torsionally deformed is disposed within the draft tube.