JPH06285348A - Method and device for agitating solid and liquid or two liquids - Google Patents

Abstract

(57) [Summary] [Purpose] To disperse powder uniformly in liquid. [Structure] A stirring tank 1 equipped with an electric stirrer 2, a screw feeder 7 whose rotation speed is controllable, and the electric stirrer 2
By a power meter 10 for measuring the load power and a programmable controller 3 for controlling the powder feeding amount, that is, the rotation speed of the screw feeder 7 so that the load power value falls within a certain deviation of the reference load power value. Composed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stirring method for uniformly dispersing powders or liquids having different specific gravities in a liquid and a stirring device therefor.

[0002]

2. Description of the Related Art In manufacturing processes for chemicals, foods, inks, rubbers, plastics and the like, there are many processes for uniformly mixing and dispersing powders or liquids having different specific gravities in a solution. An example of a conventional solid-liquid stirring device will be described with reference to FIG. 4. The stirring tank 1 is equipped with a stirrer 2 inside, a solution supply pipe 5 for supplying a solution, and a screw feeder 7 for supplying powder. I have it.

In the solid-liquid dispersion, first, the solution is poured from the solution supply pipe 5 into the stirring tank 1 and then the stirring tank 1
The programmable controller 3 closes the electromagnetic valve 6 on the basis of the weighing signal from the load cells 8, 8 supporting the above, and a predetermined amount of the solution is supplied into the stirring tank 1. Next, in a state where the agitator 2 is started by a command from the programmable controller 3, the powder is continuously and quantitatively charged by the screw feeder 7.

[0004]

However, in the case of the above-mentioned dispersion and mixing of liquid and powder, since two substances having different specific gravities and viscosity properties are mixed, the powder is uniformly dispersed in the liquid. Dispersing is an extremely difficult task.

Generally, when a powder is dispersed in a liquid, the powder is charged at one time, or is cut into a certain amount as described above, and the powder is stirred by a stirrer from the time of charging. However, as a result of being continuously charged regardless of whether or not mixing by stirring is sufficient, not only when they are charged all at once but also when they are metered in a fixed amount, the specific gravity of powder and liquid is Due to the difference and the difference in viscosity, a so-called uneven distribution phenomenon may occur in which the powder particles are not uniformly dispersed in the liquid but are concentrated in a part.

As a result, the quality of the mixed solution is deteriorated, and the powder amount corresponding to the uneven distribution is added, resulting in waste of the material. Also, the same problem occurs when two liquids having different specific gravities are mixed.

Therefore, a main object of the present invention is to uniformly disperse powders or liquids having different specific gravities in the liquids, thereby improving the quality of the solution and reducing the amount of the powders or liquids mixed.

[0008]

[Means for Solving the Problems] The above-mentioned problems are solved in that a powder or liquids having different specific gravities are charged into a stored liquid and stirred by a stirrer to disperse the charged powder or liquid in the stored liquid. In this case, the problem can be solved by measuring the load power of the electric motor in the stirrer and controlling the input amount of the powder or liquid so that the measured load power value falls within a certain deviation of the reference load power value.

An apparatus therefor is provided with a stirring tank equipped with an electric stirrer, and a powder or liquid supply means capable of continuously charging powder or liquid and having an adjustable amount.
A power meter for measuring the load power of the electric stirrer,
And a controller for controlling the amount of powder or liquid input of the powder or liquid supply means so that the measured load power value falls within a certain deviation of the reference load power value.

[0010]

[Function] The uneven distribution of the powder in the mixing and dispersion of the powder is that when the powder or the liquid is continuously supplied in excess of the capacity of the stirrer, sufficient stirring is not performed and a part of the powder is agglomerated. It is speculated that it will occur.

Therefore, in the present invention, the load power of the stirring motor is constantly monitored so that the stirring by the stirrer does not exceed the capacity, and powder or powder is used so that this value falls within a certain deviation of the reference load power value. Control the amount of liquid input. Therefore, while the powder or liquid is being charged, a good stirring state is constantly maintained, so that the powder or liquid to be charged can be uniformly dispersed and mixed in the stored liquid.

[0012]

EXAMPLES The present invention will be described in detail below based on examples. In FIG. 1, a stirring tank 1 includes an electric motor-driven stirring device 2 inside, and a solution supply pipe 5 for supplying a solution and a screw feeder 7 for supplying powder.
Is equipped with. An electromagnetic valve 6 is provided in the middle of the line of the solution supply pipe 5, and the opening / closing is controlled by a command from the programmable controller 3. Similarly, the screw feeder 7 is also controlled to be started / stopped by a command from the programmable controller 3, and the number of revolutions can be freely controlled by an incorporated inverter circuit or the like, so that the amount of powder to be charged can be adjusted. It is like this.

Further, an elphi monitor (power meter) 10 for measuring load power is attached to the electric motor of the agitator 2, and the load power signal measured here is sent to the programmable controller 3. There is.

A specific method of controlling the powder feeding amount will be described below while following the powder mixing operation procedure. Control amounts such as the amount of solution and the amount of powder charged in the programmable controller 3, the deceleration timing setting value (setting deviation) of the screw feeder 7, the mixing ratio, and various constants can be freely input from the touch panel 4. .

When solid-liquid dispersion is performed under such an apparatus,
First, various setting values, control amounts, etc. are input from the touch panel 4, and those values are set in the programmable controller 4. Then, press the manufacturing start button and the solenoid valve 6
The solution is supplied from the solution supply pipe 5 into the stirring tank 1. The amount of supply is the load cells 8 and 8 that support the stirring tank 1.
The weighing signal is constantly sent from the to the programmable controller 3, and when the solution reaches a predetermined weight, the solenoid valve 6 is closed and the solution supply is completed.

Next, the programmable controller 3 issues an operation command to the stirrer 2 and the screw feeder 7, and as the solution is stirred, a certain amount of powder is put into the stirring tank 1. The amount of powder input M ₁ is calculated based on the weight signal of the load cell 8. In the programmable controller 3, the previously known correlation between the powder input amount M and the theoretical viscosity η (G in FIG. 2).
The theoretical viscosity η ₁ is obtained from the actual powder charging amount M ₁ measured based on 1), and a predetermined conversion formula (W ₀ = aη ₁
The theoretical load power W ₀ at that time is obtained from + b).

On the other hand, the actual load power W _t of the electric motor of the agitator 2 is continuously measured by the elphi monitor 10, and the programmable controller 3 receiving this measurement signal causes the theoretical load power W ₀ and the actual load W _t to be measured. Electric power W
_The deviation ΔW is obtained from _t and if the deviation ΔW is less than or equal to a preset threshold ΔW ₁ , the rotation speed of the screw feeder 7 is maintained as it is, and if the deviation ΔW exceeds the threshold ΔW ₁ , the graph of FIG. The deceleration amount I ₀ that matches the deviation is obtained from G3, and is multiplied by the conversion constant γ to calculate the deceleration number γ I ₀ . Then, the set rotational speed R ₁ of the screw feeder 7 is obtained from the powder charging amount M ₁ from the graph G3 of FIG. 2, and the sum R ₀ of the set rotational speed R ₁ and the deceleration number γI ₀ is supplied to the screw feeder 7. Output as control signal.

In this way, during the powder feeding, the powder feeding amount is continuously controlled so that the load power of the agitator 2 is constantly within a certain range. If an example of this control state is shown, the control history is as shown in FIG. In FIG. 3, from t ₁ to t ₂ where the deviation ΔW exceeds the threshold ΔW ₁ , the deceleration number γI _{0 of the} screw feeder is obtained according to the graph G2 of the control block diagram shown in FIG. 2, and the set rotational speed R _{1 is} set. And the sum R ₀ of γI ₀ is output to the screw feeder 7 as a control signal. The control in this case is P operation control. Further, after _{0 to} t ₁ and t ₂ where the deviation ΔW is less than or equal to the threshold value ΔW _1, γI ₀ = 0, and the screw feeder control signal R ₀ is output at the set rotational speed R ₁ .

When the target amount of powder has been charged in accordance with the above powder amount control, the screw feeder 7 is instructed to stop and the solid-liquid stirring for one batch is completed.

The solid-liquid mixed liquid in which the powder is dispersed receives the supply request from the next step, and the programmable controller 3
An operation command is issued from the supply pump 9 to the supply pump 9, and the supply pump 9 is supplied. When the mixed liquid is exhausted in the stirring tank 1, the pump 1 is stopped and the feeding is completed.

When further mixing is performed, the above steps are repeated.

[Test Example] Under the above-described solid-liquid stirring apparatus according to the present invention, starch was used as a powder and water was used as a solution to produce a paste. In the test, a paste was produced by two types of methods, a solid-liquid stirring method according to the present invention and a conventional method shown in FIG. 4, and the doubled water ratio (total water amount / total starch amount) and finished viscosity of the produced paste. Were compared. In addition, in the case of the double water ratio test, the test was conducted under the condition that the finished viscosity of the paste was the same for comparison, and in the case of the finished viscosity test, the double water ratio was the same for comparison. The results are shown in Table 1.
And shown in Table 2.

Since the double water ratio is replaced with the ratio of starch molecules containing water molecules, the starch (powder) is replaced with water (liquid).
The more uniformly dispersed it is, the more water molecules are taken in, resulting in a higher water doubling ratio of the paste. The more evenly dispersed the starch, the more friction between starch molecules and water molecules. Since the viscosity of the finished glue increases, it is possible to make relative evaluations of each other.

[0024]

[Table 1]

[0025]

[Table 2]

From the test results shown in Table 1, it has been found that the method of the present invention increases the water doubling rate by about 7% as compared with the conventional example. Further, from the test results of Table 2, it is found that the viscosity of the finished paste is increased by 25% in the case of the method of the present invention as compared with the conventional method. From this, it is found that the starch of the present invention can be uniformly dispersed, and as a result, the required paste viscosity can be secured even if the amount of starch is reduced.

The case of solid-liquid agitation has been described above as an example, but even when two liquids having different specific gravities are mixed, the charged liquid is uniformly dispersed in the stored liquid by the substantially same constitution. It can be mixed.

[0028]

As described above in detail, according to the method of the present invention,
It is possible to uniformly disperse powder or liquids having different specific gravities in the stored liquid, thereby improving the quality of the mixed solution and reducing the amount of powder or liquid mixed.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a device of the present invention.

FIG. 2 is a control block diagram in the solid-liquid stirring method of the present invention.

FIG. 3 is a control history diagram of deviation power and control signals in the control method of the present invention.

FIG. 4 is a diagram showing an outline of a conventional device.

[Explanation of symbols]

1 ... Stirring tank, 2 ... Stirrer, 3 ... Programmable controller, 4 ... Touch panel, 5 ... Solution supply pipe, 6 ... Solenoid valve, 7 ... Screw feeder, 8 ... Load cell, 9 ...
Feed pump, 10 ... Elphi monitor (power meter)

Claims (2)

[Claims] 1. A load of an electric motor in the stirrer when a powder or liquids having different specific gravities are charged into the stored liquid and stirred by a stirrer to disperse the charged powder or liquid in the stored liquid. A solid-liquid or two-liquid stirring method, which comprises measuring the electric power, and controlling the amount of the powder or liquid charged so that the measured load electric power value falls within a certain deviation of the reference load electric power value. 2. A stirring tank equipped with an electric stirrer, a powder or liquid supply means capable of continuously charging powder or liquid and having an adjustable amount of charge, and for measuring load power of the electric stirrer. And a controller for controlling the powder or liquid input amount of the powder or liquid supply means so that the measured load power value falls within a certain deviation of the reference load power value. Solid-liquid or two-liquid stirring device.