JPS62244429A - Stirrer - Google Patents

Abstract

PURPOSE:To efficiently stir high viscous liquid even at cooling time by arranging coils for cooling and heating with a definite interval from the inner wall surface of a cylindrical stirring tank and using a stirring vane having a specified shape and forming a vertical circulation stream of liquid which is circulated in the inside and the outside of coils. CONSTITUTION:H-type or U-type stirring vanes 5a, 5c are fitted to a rotary shaft 3 of the center of a stirring tank slantingly upward for the rotating direction of the rotary shaft. Further paddle stirring vanes 56 are fitted by shifting at 90 deg. for these slantingly downward for the rotating direction. When rotating the rotary shaft, liquid in the central part of the stirring tank is fluidized to the upper part and then fluidized in the lower direction along the inner wall surface through the outside of coils 2 for cooling and heating which are provided apart from the inner wall surface 6 and a circulation stream is formed. Thereby even liquid heaving high viscosity of about 50,000cps can be extremely efficiently stirred and uniform mixing and heat exchange are enabled in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stirring device for high viscosity liquids, which has coils for cooling and heating inside a stirring tank.

BACKGROUND ART Liquids with high viscosity have poor stirring efficiency, making it difficult to quickly and uniformly heat or cool the liquid. Therefore, attempts have been made to arrange cooling/heating coils inside the stirring tank in order to improve cooling or heating efficiency in stirring and mixing devices for highly viscous liquids, but in this case, the rotation of the stirring blades is obstructed. The coil was placed outside the stirring blade and close to the inner wall of the stirring tank to prevent this from happening.

Problems to be Solved by the Invention However, in such a device, when cooling water is passed through the coil, supercooling occurs between the coil and the inner wall surface of the stirring tank if the liquid has a high viscosity, and this portion The disadvantage is that the viscosity of the liquid increases, and the liquid near the coil no longer flows, making stirring partially impossible.

An object of the present invention is to provide a stirring device in which a cooling/heating coil is disposed inside a stirring tank, which can stir and mix a highly viscous liquid while efficiently cooling or heating it.

Steps to Solve the Problems The device of the present invention is a cylindrical stirring tank with a rotating shaft in the center, and a cooling/heating device is installed at a certain distance from the inner wall of the stirring tank around the rotating shaft. It is characterized in that an anchor-shaped or seed-shaped stirring blade is attached to a rotating shaft, and the stirring blade is rotatably positioned inside.

That is, inside a cylindrical stirring tank with a rotating shaft in the center, coils for heat exchange are arranged in a cylindrical shape around the rotating shaft and at regular intervals from the inner wall of the stirring tank. A plurality of stirring blades are rotatably attached to a rotating shaft in a cylindrical space formed by a coil, and the lower part of the rotating shaft is held by a bearing, and the uppermost part of the stirring blades is The wing at the lower end is substantially U-shaped or 1
)-shaped stirring blades, which are attached to the rotating shaft so as to be inclined upward with respect to the rotating direction of the rotating shaft.The second blade from the bottom is a seed-shaped stirring blade, and when rotating, At a position lower than the tip of the U-shaped or H-shaped stirring blade, and downward with respect to the rotational direction of the rotating shaft, so as to rotate within the locus drawn by the U-shaped or H-shaped stirring blade. It is characterized by being tilted and attached to a rotating shaft.

In the present invention, in conventional stirring and mixing of high viscosity liquids,
Cooling and heating coils, which were thought to harm stirring efficiency during cooling, are placed at a certain distance from the inner wall of the stirring tank, and the stirring flow generated by the rotation of the stirring blades is discharged through the gaps between the coils. This makes it possible to create turbulent flow throughout the stirring tank, even for highly viscous liquids, and achieve efficient stirring.

Furthermore, in the present invention, since a plurality of stirring blades are used in combination with a specific shape and angle, an upward flow is generated in the center of the stirring tank, which flows downward along the inner wall surface of the stirring tank outside the coil. As a result, the liquid inside the stirring tank does not stagnate and is mixed in a circulating flow throughout the tank. During this time, the flowing liquid is efficiently cooled or heated by the coil or jacket, and quickly Uniform stirring and mixing becomes possible.

In addition, in the apparatus of the present invention, since the lower part of the rotating shaft is held by a bearing, even when stirring a highly viscous liquid, the rotating shaft can be stably stirred without causing lateral vibration.

The substantially U-shaped or H-shaped agitating blade at the bottom and the seed-shaped agitating blade above it are installed with an angle shifted by 90 degrees.
This is preferable because it allows the rotating shaft to rotate in a well-balanced manner and improves stirring efficiency. In addition, the substantially U-shaped or H-shaped stirring blades are attached to the rotating shaft so as to be inclined at an angle of about 60 to 80 degrees with respect to the horizontal plane, and the seed-shaped stirring blades that rotate inside the rotating shaft are tilted at an angle of about 60 to 80 degrees with respect to the horizontal plane. It is preferable to attach it to the rotating shaft so that it is inclined at an angle of about 50 to 60 degrees. Note that, as described above, the inclinations of these two types of stirring blades are opposite to each other.

The stirring blades are a combination of a substantially U-shaped or H-shaped stirring blade and a seed-shaped stirring blade, such as in a double series, but it is preferable to use these repeatedly in multiple stages, and in this case,
It is preferable to use H-shaped stirring blades in the lowest combination, and use U-shaped stirring blades in the other combinations.

The ratio of the cross-sectional area of the inner cylindrical portion of the coil to the cross-sectional area of the annular portion between the coil and the inner wall surface of the stirring tank is 1 to 1.5:
] It is preferable to set the number at a position such that the ratio is about 1.3:1, and it can be used most efficiently.

The gap between the top and bottom of the coil is preferably equal to or larger than the diameter of the tube forming the coil, and is usually 70 mm or more. As a result, the liquid in the cylindrical part inside the coil is discharged upward by the stirring blade, and the gap between the upper and lower tubes of the coil,
Alternatively, a downward circulating flow is generated from the space above the coil to the outer annular portion of the coil. As a result, stirring efficiency is significantly increased even for highly viscous liquids, and extremely efficient cooling or heating mixing becomes possible.

Generally, a cooling/heating jacket is attached to the lower outer periphery of the stirring tank, but the cooling/heating jacket may be attached to be divided into upper and lower parts so that the lower part of the stirring tank can be cooled or heated.

Further, the coils may be installed in duplicate in order to increase the heat exchange efficiency, or may be installed in multiple stages so that cooling water or heating liquid can pass through some of them depending on the amount of liquid.

Next, the present invention will be explained in more detail according to an embodiment shown in the drawings.

The device shown in the drawing has a rotating shaft (3) in the center of a cylindrical stirring tank (1) with an inner diameter of 2200 mm, and a cooling/heating coil (3) consisting of a tube with a diameter of 76.3 mm centered around this rotating shaft (3). 2) are arranged in a double cylindrical shape.The outer coil (2) has a diameter (PCD) of 1750 mm and the inner coil (2) has a diameter (PCD) of 1500 mm.

The cross-sectional area A of the inner cylindrical part of the coil (2) is (1, 4,
62) 2Xπ/4 = 1.679 m", and the cross-sectional area B of the annular portion formed between the coil (2) and the inner wall surface (6) of the stirring tank (1) is ((2,200)2xπ/ 4] -((1,788)2xπ/4]-1,290 m". Therefore, the ratio of cross-sectional area A,!:B is 1,679 m
2/1.290m2=1.30.

In addition, the gap between the upper and lower tubes of the coil (2) is set at a pitch of 150
mm - tube diameter 76.3 mm = 73.7 mm.

An H-shaped stirring blade (5a) is attached to the lowermost end of the rotating shaft (3), and a seed-shaped stirring blade (5b) is mounted on top of the H-shaped stirring blade (5a) in a rotatable state inside the stirring blade (5a). ) is attached. Furthermore, three sets of U-shaped stirring blades (5C) and seed-shaped stirring blades (5b) are attached above and below the stirring blades, with the latter rotatable inside the former.

The H-shaped or U-shaped stirring blades (5a) (5c) and the seed-shaped stirring blade (5b) are attached to the rotating shaft (3) with a 90° offset. 5a) and the U-shaped stirring blade (5c) are both installed so that the left and right blades are inclined upward (at an angle of 70' with respect to the horizontal plane) with respect to the rotational direction of the rotating shaft (3). stirring blade (5b)
Both left and right wings are mounted so as to be inclined downward (at an angle of 55° with respect to the horizontal plane) with respect to the rotational direction of the rotating shaft (3).

The tip of the rotating shaft (3) is held by a bearing (4), and a cooling/heating jacket (7) is attached to the outer periphery of the stirring tank fl) divided into upper and lower halves.

The liquid placed in the stirring tank (1) is stirred and mixed while being cooled or heated by water or heated steam introduced into the coil (2) and jacket (7). Wings (5a) (5b) (5c)
Due to the rotation of the coil (2), the liquid inside the coil (2) flows upward and passes through the gap between the upper and lower tubes of the coil (2).
), a downward flow is generated along the inner wall surface (6) of the stirring tank (1) to form a circulating flow. However, it can be stirred very efficiently, and uniform mixing and heat exchange can be achieved in a short period of time.

Effects of the Invention The stirring device of the present invention generates an upward flow in the center of the stirring tank, and directs the flow downward along the inner wall surface of the stirring tank, without causing the liquid inside the stirring tank to stagnate. The whole can be mixed as a circulating flow, and this circulating flow is always efficiently cooled or heated by the coil or jacket, so even highly viscous liquids can be stirred and mixed very quickly and uniformly.

Note that the apparatus of the present invention can be effectively used particularly when mixing liquids whose viscosity changes or when dissolving solids in liquids.

[Brief explanation of drawings]

The drawing is a cross-sectional view of the device of the invention. (1) Stirring tank (5a) (5b) (5c)
Stirring blade (2) Coil (6) Inner wall surface (
3) Rotating shaft (7) Jacket (4)
bearing

Claims (6)

[Claims] (1) Cylindrical stirring tank (1) with a rotating shaft (3) in the center
There is a stirring tank (1) centered around the rotating shaft (3) inside the
A coil (2) for heat exchange is arranged in a cylindrical shape at a constant interval from the inner wall surface (6) of the coil (2), and a plurality of stirring blades are formed by the coil (2). It is attached to the rotating shaft (3) in a state that it can rotate in space, and the lower part of the rotating shaft (3) is held by a bearing (4), and the lowermost blade of the stirring blade is substantially U. It is a stirring blade (5a) in a shape of a shape or an H shape, and a rotating shaft (3).
The second blade from the bottom is a paddle-shaped stirring blade (5b), which is attached to the rotating shaft (3) so as to be inclined upward with respect to the rotation direction of the blade. At a position lower than the tip of the U-shaped or H-shaped stirring blade (5a), in the rotational direction of the rotating shaft (3) so as to rotate within the locus drawn by the stirring blade (5a). A stirring device characterized in that it is attached to a rotating shaft (3) so as to be inclined downward. (2) The paddle-shaped stirring blades (5b) are U-shaped or H-shaped.
Claim 1, characterized in that the stirring blade (5a) is attached at an angle of 90° with respect to the letter-shaped stirring blade (5a).
Stirring device as described in section. (3) The device according to claim 1, wherein a cooling/heating jacket (7) is attached to the lower outer periphery of the stirring tank (1). (4) The device according to claim 3, wherein the cooling/heating jacket (7) is attached in upper and lower parts. (5) The device according to any one of claims 1 to 3, wherein the coil (2) is installed in duplicate. (6) The device according to any one of claims 1 to 5, wherein the coils (2) are installed in multiple stages.