JPS6295122A - Uniform agitation method - Google Patents

Abstract

PURPOSE:To uniformly agitate and mix a soln. notwithstanding the viscosity of the soln. by concentrically providing plural agitating blades, differentiating the rotating conditions of an appropriate number of the agitating blades from the rotating conditions of other rotating blades, and rotating the blades. CONSTITUTION:Rotating cylindrical 5 and 6 equipped with agitating blades 2, 3, and 4 at the lower ends and a rotating shaft 7 are concentrically hung at the central part of a large-sized agitated vessel 1. Adjustable speed motors 14 and 15 are connected to the upper end parts of the rotating cylindrical shafts 5 and 6 through gears 8-11, and an adjustable-speed motor 17 is connected to the upper end of the rotating shaft 7. The device is used, the motors 14 and 17 are driven at 400-600 r.p.m., and the soln. (a) is agitated by the agitating blades 2 and 4 for about 2min. Then the motors 14 and 17 are stopped, hence the agitating blades 2 and 4 are stopped, the motor 15 is driven at 400-600 r.p.m., and the soln. (a) is agitated by the agitating blade 3. The agitation and stoppage are repeated and the soln. is uniformly agitated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention mainly relates to a uniform stirring method for uniformly stirring a solution using a plurality of stirring blades when stirring a solution in a large stirring tank. .

[Prior art and its problems] Generally, in order to stir a solution in a large stirring tank, stirring blades such as turbine blades or screw blades are arranged concentrically in multiple stages in the tank, and these stirring blades are simultaneously moved at a constant speed. The solution was stirred by rotation.

However, if the stirring blades arranged concentrically in multiple stages are rotated at the same speed at the same time, the solution will only be stirred in the radial direction (horizontal direction) at each stage, but will not be stirred in the axial direction (vertical direction). Therefore, uniform stirring cannot be expected.

In other words, for example, when stirring blades are installed in two or three stages, the inside of the stirring tank is divided into two or three layers, and experiments have shown that the metal bodies in the tank are stirred non-uniformly. The above is clear. This is particularly noticeable in highly viscous solutions.

[Summary of the invention] The present invention provides a stirring tank by rotating an appropriate number of stirring blades among a plurality of stirring blades installed concentrically and under different rotation conditions of other stirring blades. By providing a uniform stirring method in which the solution in the stirring tank is stirred, the problems in the conventional stirring method described above are solved, and the solution in the stirring tank is uniformly stirred regardless of its type. The purpose is to do so.

[Example] Hereinafter, an example of the uniform stirring method according to the present invention will be described based on the drawings.

The apparatus used in this embodiment includes a rotary cylinder shaft 5.6 and a rotary shaft 7 concentrically suspended from the center of a large stirring tank 1, each having a stirring blade 2.3.4 attached to its lower end. At the upper end of each rotating cylinder shaft 5.6.

Reducible speed motors 14 and 15 are connected via gears 8 to 11, and a decelerable speed motor 17 is connected to the upper end of the rotating shaft 7.

Here, as for the stirring blades 2.3.4, the lower stirring blade 4 is the largest, the middle stirring blade 3, and the upper stirring blade 2.
The smallest size is used in this order.

In order to uniformly stir the solution a in the stirring tank 1, for example actinomycetes having a viscosity of 3 to 4 poise, using such a device, the following method is used.

Example 1) Motor 14.17 400~600r, p, m
(7) Rotate at the set stirring speed and stir the solution a for a certain period of about 2 minutes with the stirring blade 2.4. During this time, the motor 1
Leave 5 still.

Next, after approximately 2 minutes have elapsed, the motor 14.17 is stopped, the stirring blade 2.4 is brought to a standstill, and at the same time, the motor 15.
is rotated at 400 to 600 r, p, m, and the stirring blade 3 stirs solution a for about 2 minutes.

Uniform stirring is performed by repeating the above stirring and stopping.

Example 2) The motor 17 is rotated at a set stirring number of 400 to 600 r, p, m, and the stirring blade 4 stirs the solution & for a certain period of about 2 minutes, during which time the motors 14 and 15 are kept stationary.

Next, after approximately 2 minutes have passed, the motor 17 is stopped, and the
While keeping the H stirring blade 2.4 stationary, the motor 15
is rotated at 400 to 600 r, p, m, and the stirring blade 3 stirs solution a.

Next, after approximately 2 minutes have elapsed, the motor 15 is stopped, and the stirring blades 3.4 are placed in a stationary state, and at the same time, the motor 14 is
00 to 800 r, p, and the solution a is stirred with the stirring blade 2 for about 2 minutes.

Uniform stirring is performed by repeating the above three series of stirring and stopping.

Example 3) Motor 14.17 400~800r, p, +a
Rotate at the set stirring speed, and use the stirring blade 2.4 to mix solution a.
At the same time, the motor 15 stirs the stirring blade 3.
40 to BOr so that the stirring flow of the solution a caused by the stirring blade 2.4 does not greatly disturb the stirring flow of the stirring blade 2.4.

Rotate at a stirring speed of pl, and stir solution a for about 2 minutes in this state. Next, after about 2 minutes,
The motor 15 is rotated at a stirring number of 400 to 800 r, p, m, and at the same time, the stirring blade 3 stirs the solution a.
The motors 14 and 17 are rotated at a stirring number of 40 to BOr, p, +s, and solution a is stirred in this state for about 2 minutes.

Uniform stirring is achieved by repeating the staggered rotation described above.

Note that the above stirring examples are merely illustrative, and it is obvious that the stirring conditions may be varied depending on the type and properties of the solution to be stirred, without being limited thereto.

[Effects] As described above, in the present invention, since the plurality of stirring blades stir the solution under different rotation conditions, the solution in the stirring tank can be mixed both in the radial direction (horizontal direction) and in the axial direction. (Vertical direction) as well, which has the effect of uniform stirring and mixing regardless of the viscosity of the solution.

In addition, in cases where the rotation conditions are repeated rotation and rest with a rotational speed or time difference, or where a plurality of stirring blades are of different sizes, the stirring effect of the solution, that is, the uniform mixing effect increases. There is an advantage that

[Brief explanation of drawings]

The drawing is an explanatory diagram showing an example of an apparatus used in the uniform stirring method according to the present invention. 1... Stirring tank 2.3.4... Stirring blade a... Solution

Claims (4)

[Claims] (1) The solution in the stirring tank is stirred by rotating an appropriate number of stirring blades among a plurality of stirring blades installed concentrically and under different rotation conditions of the other stirring blades. A uniform stirring method characterized by: (2) Claim 1 in which the rotation condition is rotation speed
Uniform stirring method described in section. (3) The uniform stirring method according to any one of claims 1 and 2, wherein the rotation condition is a repetition of rotation and rest with a time difference. (4) The uniform stirring method according to any one of claims 1 to 3, wherein the plurality of stirring blades are stirring blades of mutually different sizes.