KR100437564B1 - Agitator for solving non-uniform agitating problems due to weissenberg effects - Google Patents

Abstract

PURPOSE: Provided is an agitator to be simply manufactured, to be practically used by slightly modifying an existing agitator, and to enhance agitation efficiency by inclining a agitation tank with respect to a horizontal surface. CONSTITUTION: The agitator for agitating two or more substances includes an agitation tank(A) and an impeller(B). The substances contain visco-elastic fluids. The agitation tank is inclined with respect to a horizontal surface. The inclined angle is 20-70 degree. The center shaft(C) of a rotation of the impeller is not immersed into the substances to be agitated. The agitation tank is provided at lowermost corner thereof with exhaust valve(E). The inlet portion of the exhaust valve is in the form of a funnel to allow the contents to be easily discharged. The space between the inner face of agitation tank and the rotation face of the impeller is minimized.

Description

Stirring device and method

The present invention inclines the stirring tank of the stirring device with respect to the horizontal plane, and the rotational axis of the impeller does not come into contact with the solution inside the tank to increase the stirring efficiency and solve the problem of non-uniform stirring due to the Weissenberg effect. It relates to a stirring device and a method.

In general, when a polymer is polymerized, a solution is prepared, an additive is added, or two or more substances are mixed, a stirring device and a method capable of uniformly stirring in a short time are required. In particular, if the material used is a viscoelastic fluid, which is a non-Newtonian fluid, the Weisenberg effect, a phenomenon in which the viscoelastic fluid rises on the central axis during stirring, may occur, which causes a decrease in the stirring efficiency and prevents uniform stirring. There was a problem.

Among the conventional methods, the Japanese patent publication 93-1110 introduces a passage to the rotating and rotating shaft of the container so that excess fluid is discharged, or the Korean Utility Model Publication 95-0216 uses a propeller that is rotated by a driving motor. And uniformly stirring. In Korea Utility Model Publication 94-0224, 94-0412, the stirring efficiency is increased by installing screws.

However, such a stirring method and agitating device has a problem in the practical use of the device and method because the structure is complicated and difficult to manufacture.

The present invention is simple to manufacture and can be used by slightly modifying the existing stirring device, there is no particular difficulty in practical use, and its purpose is to provide a stirring device and method excellent in stirring efficiency.

1 is a schematic view of a stirring device according to the present invention.

2 is a stirring apparatus used in Comparative Example 5 of the present invention.

3 is a stirring apparatus used in Comparative Example 6 of the present invention.

* Explanation of Signs of Major Parts of Drawings *

A: stirring tank, B: impeller, C: impeller rotation center shaft,

E: discharge valve, D: stirring material, α: inclination angle of the stirring tank.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

As illustrated in FIG. 1, the stirring tank A is inclined at a constant inclination angle α with respect to a horizontal plane to increase agitation efficiency. As for the inclination angle (alpha) with respect to the horizontal surface of the stirring tank A, 20 degrees-70 degrees are suitable.

If less than 20 ° or more than 70 °, there is a disadvantage in that the stirring efficiency falls. In addition, the main shaft (C) of the impeller (B) is not immersed in the agitated material (D) in the stirring tank (A) so that when the contents are viscoelastic fluid, the viscoelastic fluid rises on the central shaft (C). It can prevent the Werck effect and increase the stirring efficiency.

As well as the present invention, since the stirring tank (A) is inclined with respect to the horizontal plane, the inlet portion of the discharge valve (E) naturally becomes a funnel, so that the contents can be easily discharged by self-weight or pressure. And since the gap between the inner surface of the stirring tank (A) and the rotating surface of the impeller (B) is minimized, the stirring efficiency can be further improved.

Example 1

As the polymerization reactor, use a stirring device such as 1st degree, set the inclination angle α to the horizontal plane of the stirring tank at 45 °, and keep the terephthalic acid and ethylene glycol in the usual way so that the center of rotation of the impeller does not contact the contents. The esterification and polycondensation reaction yielded a polyethylene terephthalate polymer melt having an intrinsic viscosity of 0.64. The red pigment was added to the red silicone oil quantitatively added, and the stirring was performed at a rotational speed of 15 rpm. The time when the red silicone oil was uniformly mixed with the polyethylene terephthalate melt was measured by visual observation while discharging the stirred matter through the outlet. 5 minutes after the start of the stirring, the impeller and the central axis of rotation were observed to measure the height of the stirring material on the shaft based on the surface of the agitated material. The results are shown in Table 1.

Examples 2-5

Except that the inclination angle (α) with respect to the horizontal surface of the stirring tank is 20 °, 30 °, 60 °, 70 ° was carried out in the same manner as in Example 1 and the results are shown in Table 1.

Comparative Examples 1 to 4

Except that the inclination angle (α) with respect to the horizontal plane of the stirring tank was carried out in the same manner as in Example 1 except that it is 0 °, 10 °, 80 °, 90 ° and the results are shown in Table 1.

Comparative Example 5

Except that the stirring tank was tilted 45 ° with respect to the horizontal plane and the impeller rotation center was immersed in the solution using the same stirring device as shown in FIG. .

Comparative Example 6

Using the stirring apparatus as shown in FIG. 3, the stirring tank was perpendicular to the horizontal plane, and the results were shown in Table 1 except that the rotating shaft of the impeller was immersed in the solution. .

※ One ; Angle of inclination of the stirring tank with respect to the horizontal plane

※ 2 ; Time required for red silicone oil to mix homogeneously in polyethylene terephthalate melt

※ 3; Height that the stirring material climbs on the center of rotation

The present invention is very simple in structure and can be used simply by retrofitting the existing stirring device as well as high stirring efficiency and can prevent the Weissenberg effect.

Claims (3)

A device for agitating two or more substances containing viscoelastic fluid, wherein the stirring tank (A) is inclined at an angle of 20 ° to 70 ° with respect to the horizontal plane, and the central axis of rotation (C) of the impeller (B) is agitated. Stirring device characterized in that it is not immersed in. The stirring device according to claim 1, wherein a discharge valve (E) is provided at a lowermost corner of the stirring tank (A). In a method of stirring two or more substances containing viscoelastic fluid, the stirring tank is inclined at an angle of 20 ° to 70 ° with respect to the horizontal plane, and the stirring center is stirred so that the center of rotation of the impeller is not submerged in the agitated material. Stirring method characterized in that.

Images