JP2011251236A - Stirring blade for medium and high viscosity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stirring blade which is good in thermal conduction to a liquid in a tank, can sufficiently stir the liquid to thereby achieve uniformization of the liquid temperature, and has a simple structure and exhibits good cleanability.SOLUTION: The stirring blade comprises: a principal stirring blade portion 2 of the inside, formed wider as going downward; a forced flow-generating blade portion 3 of the outside, having an outside part 3a rotating in the vicinity of the inner peripheral surface of the tank 5; and a linking portion 4 to link the principal stirring blade portion 2 and the forced flow-generating blade portion 3, in the lower part. The principal stirring blade portion 2, the forced flow-generating blade portion 3 and the linking portion 4 are formed integrally of a platy body.

Description

  The present invention relates to a medium / high viscosity agitating blade suitable for heat transfer mixing of a medium / high viscosity hardly flowable liquid in the food industry, the chemical industry, and the like.

  Conventionally, as this kind of stirring blade, an anchor blade a as shown in FIG. 4 and a helical ribbon blade b as shown in FIG. 5 are known. In these figures, c is a tank, d is a rotating shaft, and e is a heating means provided on the outer wall of the tank c (see Non-Patent Document 1).

Edited by Satake Chemical Machinery Co., Ltd. “Agitation Technology”, published by Satake Chemical Machinery Co., Ltd., December 18, 1992, P13

  According to the anchor blade a, since the anchor blade a rotates in the vicinity of the inner peripheral surface of the tank c, the liquid is forced to flow in the vicinity of the inner peripheral surface, and the heating means e enters the tank c. However, there is a problem in that the temperature of the liquid is not uniform due to insufficient stirring and up-and-down circulation of the liquid in the tank c. For example, although the liquid in the tank c is sufficiently stirred, there is a problem in that it is difficult to perform cleaning after work due to the complicated generation and structure of a poorly heat-mixed part due to partial mixing failure.

  The present invention eliminates these problems, heat transfer to the liquid in the tank is good, and the liquid is sufficiently agitated to achieve a uniform liquid temperature, with a simple structure and good cleanability. An object of the present invention is to provide a simple stirring blade.

  In order to achieve the above-mentioned object, the present invention provides an outer forced flow generating blade portion having an inner main stirring blade portion that is formed wider toward the lower side and an outer side that rotates and moves in the vicinity of the inner peripheral surface of the tank. And the main agitating blade portion and the forced flow generating blade portion are provided in a continuous portion at the lower portion.

  According to the present invention, even if the liquid into the tank is a non-flowable liquid of medium or high viscosity, heat transfer to the liquid is good and sufficient stirring is performed so that the liquid has a uniform temperature. Further, the stirring blade itself has a simple structure with a vertical plane, and has an effect of improving the cleaning property.

It is a front view of Example 1 of the stirring blade of this invention. It is a graph which shows the relationship between the heating time in the case of stirring with the stirring blade of this invention, and the representative temperature in a tank. It is a graph which shows the relationship between the heating time in the case of stirring by the conventional anchor blade, and the representative temperature in a tank. It is a front view of the example of an anchor blade with the conventional stirring blade. It is a front view of the example of a helical ribbon blade | wing with the conventional stirring blade.

  The example of the form for carrying out the present invention is shown below.

  Embodiment 1 of the stirring blade of the present invention will be described with reference to FIG.

  FIG. 1 is a front view of Example 1 of a stirring blade.

  Reference numeral 1 denotes a stirring blade, and the stirring blade 1 includes an inner main stirring blade portion 2, an outer forced flow generation blade portion 3, and the main stirring blade portion 2 and the forced flow generation blade portion 3 arranged in a lower portion. The connecting portion 4 is integrally formed of a plate-like body.

  The main agitating blade portion 2 is formed in the shape of a triangle that is inclined obliquely outwardly as the inner side 2a is vertical and the outer side 2b is directed downward from the upper end, and the forced flow generating blade portion 3 is formed on the outer side. The side 3a is formed in a triangular shape with a sharp apex having a sloping inner side 3b that is vertical and widens downward, and further, the lower side of the connecting part, the main stirring blade part 2, and the forced flow generation blade part 3, The lower side 1a of the stirring blade 1 is formed in a curved shape along the inner bottom surface of the tank 5 described later.

  5 indicates a tank, the tank 5 is formed in a bottomed circular cylindrical shape, and the bottom surface is formed in a curved shape protruding downward, and a rotary shaft 6 is provided in a hanging manner at the center of the tank 5; A pair of the stirring blades 1 is fixed to the lower end portion of the rotating shaft 6 via a boss 7, and the outer side 3 a of the forced flow generating blade portion 3 of the stirring blade 1 is set to the inner peripheral surface of the tank 5. And the lower side 1 a of the stirring blade 1 is positioned in the vicinity of the inner bottom surface of the tank 5.

  Reference numeral 8 denotes a heating means comprising a heat transfer jacket or the like provided outward from the peripheral surface to the bottom surface of the tank 5.

  Next, the operation and effect of the stirring blade 1 of this embodiment will be described.

  When the rotary shaft 6 is driven to rotate by a motor (not shown) after filling the tank 5 with a medium and high viscosity hard-flowing liquid to a predetermined upper level, the stirring blade 1 rotates together with the rotary shaft 6. .

  In the rotation of the stirring blade 1, the main stirring blade portion 2 is narrow in the upper portion of the liquid in the tank 5 and only exists in the vicinity of the rotating shaft 6. In the lower part of the liquid in the tank 5, the main agitating blade part 2 is wide and the main agitating part is separated from the rotating shaft 6. The wing part 2 exerts a large rotational force on the liquid to increase the negative pressure. Thus, the liquid generates a strong downward flow due to the negative pressure difference of the liquid and is given a rotational force. Also in the portion 4, a rotational force is applied and flows outward along the bottom surface in the tank 5, and then flows upward along the inner peripheral surface of the tank 5 to become a circulating flow A.

  At this time, the lower side 3 a of the stirring blade 1 and the outer side 3 a of the forced flow generating blade portion 3 rotate around the inner bottom surface and the inner peripheral surface of the tank 5, so that a strong flow is generated forcibly, thus heating means 8. Heat is transferred from the liquid to the liquid satisfactorily, and the temperature of the liquid is increased uniformly throughout the entire circulation flow A.

  Here, since the stirring blade 1 has a main stirring blade portion 2, a forced flow generation blade portion 3, and a connecting portion 4 integrally formed by a plate-like body, the stirring blade 1 has a simple structure and can be cleaned. Easy to do.

  In the present embodiment, an example in which the inner side 3b of the forced flow generating blade portion 3 is inclined is shown. However, the inner side 3b may be formed vertically like the outer side 3a. Further, it is preferable to use two or more stirring blades 1.

  Next, FIG. 2 shows the experimental results of the temperature change in the tank as the heating time elapses when thermocouples are installed at the upper and lower parts of the inner periphery of the tank and stirred by the stirring blade of the present invention in the tank. On the other hand, the experimental result of the temperature change in a tank according to progress of the heating time at the time of stirring with the conventional anchor blade is shown in FIG.

From these experimental results, in the case of the stirring blade of the present invention as compared with stirring anchor blade, from an early stage of the heating time and the tank upper temperature T _a and the tank bottom temperature T _b is the same, the temperature in the tank The variation was small and uniform, and it was demonstrated that the thermal mixing performance was excellent.

  In either case, the stirring Reynolds number is about 20.

  The stirring blade of the present invention can achieve uniform temperature rise and cooling while stirring well even in the food industry, the chemical industry, etc., even in the case of a medium or high viscosity hard-flowing liquid.

DESCRIPTION OF SYMBOLS 1 Stirring blade 2 Main stirring blade part 2b Outer side 3 Forced flow generation blade part 3a Outer side 4 Consecutive part 5 Tank

Claims (4)

  An inner main agitating blade portion that is formed wider toward the lower side, an outer forced flow generating blade portion having an outer side that rotates in the vicinity of the inner peripheral surface of the tank, and these main agitating blade portion and forced flow generating blade An agitating blade for medium and high viscosity comprising a continuous portion in which the portion is continuously provided at the lower portion.   The medium / high viscosity stirring blade according to claim 1, wherein the main stirring blade portion, the forced flow generation blade portion, and the connecting portion are integrally formed of a plate-like body.   The medium / high viscosity stirring blade according to claim 1, wherein the main stirring blade portion is formed in a triangular shape whose outer side is inclined.   3. The medium / high viscosity stirring blade according to claim 1, wherein the forced flow generating blade portion is inclined inward or vertically with an inner side facing downward.

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