JP6024344B2 - Reaction liquid viscosity detection method and apparatus, and reaction liquid generator - Google Patents

Description

  The present invention relates to a method for detecting the viscosity of a reaction liquid using an induction motor as a power source, an apparatus for the method, and an apparatus for generating the reaction liquid.

In Patent Document 1, the present inventors have detected the viscosity of a reaction liquid installed in a reactor that stirs the reaction liquid by rotating a rotating shaft provided with a stirring blade using an electric motor driven by an inverter as a power source. A device is proposed.

In Patent Document 1, a method for calculating rotational torque with high accuracy using various measurement parameters supplied for the operation of an electric motor, and a method for detecting the viscosity of a reaction liquid with little variation from the detected value of the rotational torque. The viscosity detection device employing this method has the following means 1) to 5), and the input power (P _I ) and loss power obtained from the values measured by the respective measuring instruments. Based on (P _L ) and angular velocity (ω),
T = (P _I −P _L ) / ω
Thus, the rotational torque (T) is obtained by calculating the viscosity of the reaction liquid from the rotational torque.
1) A power measuring device that measures the power supplied to the motor 2) A current measuring device that measures the current supplied to the motor 3) A voltage measuring device that measures the voltage supplied to the motor 4) Rotation of the motor Rotational speed measuring instrument that measures shaft speed 5) Frequency measuring instrument that measures inverter output frequency

The viscosity detection of Patent Document 1 can detect the rotational torque with high accuracy based on the measurement values obtained by each of the means 1) to 5), and as a result, know the relative viscosity of the reaction liquid with high accuracy. be able to.

  The rotational torque of the stirring blade detected in Patent Document 1 is a rotational torque component generated when the reaction liquid charged in the reactor is zero, that is, a rotating mechanical mechanism such as a speed reducer or a bearing that does not contribute to the stirring of the reaction liquid. The generated loss torque (hereinafter, simply referred to as null torque) is included. Therefore, in this document, this value is measured in advance and treated as a constant, and is subtracted from the detected torque value, that is, a procedure for obtaining the net torque used for stirring the reaction solution by performing empty torque correction. It is shown.

However, as a result of further intensive studies by the inventor, it has been found that the method disclosed in Patent Document 1 needs to be improved when continuously used for a long time. That is, there is a lubricating oil type speed reducer that reduces the rotational speed of the induction motor between the rotation shaft of the induction motor and the rotation shaft provided with the stirring blades when the seasonal variation of the environmental temperature is large throughout the year. In the case where it is installed, the viscosity resistance of the lubricating oil changes depending on the environmental temperature, so that a situation where it is difficult to perform reliable viscosity evaluation has been encountered.

As means for solving the above-mentioned problem, for example, in Patent Document 2, the rotational torque applied to the rotating shaft of the prime mover is measured after the temperature of the lubricating oil of the lubricating oil type reduction gear is adjusted to be constant with a heat exchanger. Describes an apparatus for determining the viscosity of a reaction solution based on the rotational torque.

However, in this known and conventional apparatus, in order to control the temperature of the lubricating oil of the lubricating oil type reduction gear, it is indispensable to provide not only a heat exchanger but also an auxiliary facility such as a pump, and the reaction product is handled. In chemical factories and the like, many devices for satisfying the explosion-proof equipment standards such as d2G4 are required, so that they have to be large and complicated.
From the above situation, it is desired to provide a simple and more accurate reaction liquid viscosity detector.

Further, the viscosity detector described in Patent Document 1 requires a measuring instrument as an entity to know the rotational speed. For devices that measure rotational speed, contact type (mechanical type) and non-contact type (optical type, electromagnetic type) depending on the method of measurement, digital type and analog type depending on the processing method of measurement signal, Depending on the place of use, it is classified into an explosion-proof type and a non-explosion-proof type, both of which are known as conventional equipment.

  For example, a digital handy tachometer (Ono Sokki HT-5500) with both contact and non-contact types, visible light type tachometer (Hioki Electric FT3405), electromagnetic rotation measuring instrument (Hioki Electric MP-200), explosion-proof rotation Measuring instruments (Ono Sokki RP-200) are known, and these measuring instruments can be used with high accuracy and safety by being appropriately selected according to the application.

A rotational speed measuring instrument used in a factory that handles a reaction liquid containing a flammable liquid needs to satisfy explosion-proof standards. Rotational speed measuring instruments that meet the explosion-proof standards are expensive, and not only increase the installation cost of the viscometer, but also have a long delivery time, and there is a problem that it is difficult to spread due to production stoppage at the time of installation. Therefore, it is desired to detect the rotation speed of the induction motor without using a rotation speed measuring instrument.

JP 2010-190882 A JP-A-10-237181

  In view of the background art, the present inventor includes a viscosity detection method for a reaction liquid that detects the viscosity of the reaction liquid with high accuracy without using a known and commonly used temperature adjusting device for the lubricating oil, and the viscosity detection method. It is an object of the present invention to provide a reaction liquid viscosity detection apparatus and a reaction liquid generation apparatus using the viscosity detection apparatus.

  In addition, the present inventor is to provide the above-described method and apparatus capable of obtaining the same accuracy as in the case of using the rotational speed measuring device even when the rotational speed measuring device as a publicly known and commonly used entity is not used. .

In order to solve the above problems, the present inventor
A reactor that stirs the reaction liquid by rotating a rotating shaft provided with a stirring blade using an induction motor as a power source; and
A rotating shaft of the induction motor;
Between the rotating shaft provided with the stirring blade, a lubricating oil type speed reducer that reduces the rotation speed of the induction motor is installed.
In the reactor,
A method for detecting the viscosity of the reaction solution,
1) Induction motor torque (Ts) detection process,
2) a temperature detection step for detecting the lubricating oil temperature (t);
It is possible to calculate a highly accurate rotational torque (T) by performing a specific calculation based on the value of the detection output obtained in each of the above steps, and to further calculate the rotational torque (T). By finding a method capable of detecting the viscosity of the reaction liquid based on the detected value, the inventors have completed the viscosity detection method for the reaction liquid of the present invention.

The characteristic of the viscosity detection method of the reaction liquid in the present invention is that the induction motor torque Ts and the lubricant temperature t are

T = Ts−F (t)

The rotational torque (T) can be obtained as follows.
However, F (t) is a temperature t based on a value detected by detecting a plurality of sets by changing the temperature when the reaction liquid is empty when the temperature of the lubricating oil is t. A function regression formula.

  That is, according to the present invention, even if the viscosity resistance of the lubricating oil changes greatly depending on the environmental temperature or operation time, the viscosity resistance of the lubricating oil is determined according to the temperature. It has been found that by detecting the torque when the reaction liquid is empty based on the temperature of the lubricating oil, the detection accuracy of the rotational torque (T) is remarkably increased.

Furthermore, even when the present invention does not use a rotational speed measuring instrument as an entity,
Since the step of obtaining the induction motor torque Ts includes the following steps, it has been found that the same result as that obtained when the rotational speed measuring device is used can be obtained.
1) the power loss when the input power P to the induction motor is supplied with P _L,
The power loss PL is _divided into power loss A that does not depend on the rotational speed of the rotating shaft of the induction motor and power loss B that depends on the rotational speed.
The difference between the input power P and the loss power A is regarded as a first-order approximate value PM ₁ of the mechanical output of the induction motor, and the relational expression PM ₁ = αS ₁ (α Step I for obtaining a first order approximate value N ₁ = N _S (1−S ₁ ) (N _S is a synchronous speed) from the rotation speed of the rotating shaft from
Step II for determining the power loss B ₁ based on the primary approximation N ₁ ;
Considering the second-order approximate value PM ₂ of the output of the induction motor as P− (A + B ₁ ),
From the relational expression PM ₂ = αS ₂ (α is a motor constant) between the known output PM and the slip S for the induction motor, a second-order approximate value N ₂ = N _S (1-S ₂ ) _{(N S} is the motor constant) rotational speed detection process including step III seeking.
2) Based on the input power P, the lost power A, the lost power B ₁ obtained in step I of the rotational speed detection step, and the second order approximate value N ₂ of the rotational speed obtained in step III. , the following equation _{Ts = (P- (A + B} 1)) / (2π × N 2/60)

Rotational torque detection step for obtaining the induction motor torque Ts by

The present invention also relates to an apparatus for detecting the viscosity of a reaction solution,
An induction motor as a power source, installed in a reactor that stirs the reaction liquid by rotating a rotating shaft equipped with a stirring blade; and
A rotating shaft of the induction motor;
Between the rotating shaft provided with the stirring blade, a lubricating oil type speed reducer that reduces the rotation speed of the induction motor is installed.
An apparatus for detecting the viscosity of the reaction solution,
The apparatus has 1) a means for detecting the induction motor torque (Ts), 2) a temperature detecting means for detecting a lubricating oil temperature (t), and
The viscosity of the reaction solution is
From the induction motor torque Ts,

T = Ts−F (t)

Thus, the present invention has come to produce a viscosity detector for a reaction liquid characterized by comprising a calculation means for calculating the rotational torque (T) from the rotation torque and further calculating the viscosity of the reaction liquid from the rotation torque.
However, F (t) is a temperature t based on a value detected by detecting a plurality of sets by changing the temperature when the reaction liquid is empty when the temperature of the lubricating oil is t. A function regression formula.

  The present invention also relates to an apparatus for producing a reaction liquid, and has come to produce a reaction liquid production apparatus characterized by using a viscosity detection device for the reaction liquid.

  According to the present invention, high accuracy can be obtained even if the viscosity resistance of the lubricating oil of the lubricating oil type reduction gear greatly changes depending on the environmental temperature and operating time without providing the above-mentioned known conventional device in an explosion-proof area such as a chemical factory. Thus, the rotational torque (T) can be detected, and the viscosity of the reaction liquid can be detected based on the rotational torque detection value. Further, since the rotational speed can be detected without providing a speed measuring device as an entity, it is not necessary to use the speed measuring device. Therefore, it is possible to provide a reaction liquid viscosity detection apparatus that is simple and low in cost, and a reaction liquid generation apparatus using the apparatus.

It is a graph which shows the relationship between the slip S of an electric motor, and the machine output PM. It is typical sectional drawing explaining the various dimensions of the container provided with the stirring blade. It is a figure which shows schematic structure of the stirring apparatus of the reaction liquid which concerns on embodiment. Detection methods in which the present invention applies indicating the rotational speed and the speed chart shown together actual rotational speed obtained in (quadratic approximation value N _2). It is a graph which shows the torque detection value when the reaction liquid is empty when the temperature of the lubricating oil of the lubricating oil reduction gear is t. The correlation analysis with the viscosity of the reaction liquid detected by applying patent document 1 is shown. The correlation analysis with the viscosity of the reaction liquid detected by applying this invention is shown. It is drawing which shows typically the temperature characteristic of the viscosity of a general reaction liquid. It is drawing which showed the value of Formula (13) detected by changing the input amount of the product to the reaction container (9) with the typical curve.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
The feature of the viscosity detection method of the reaction liquid in the present invention is:
A reactor that stirs the reaction liquid by rotating a rotating shaft provided with a stirring blade using an induction motor as a power source; and
In a reactor in which a lubricating oil type speed reducer for reducing the rotation speed of the induction motor is installed between the rotation shaft of the induction motor and the rotation shaft provided with the stirring blade,
A method for detecting the viscosity of the reaction solution,
1) Induction motor torque (Ts) detection process,
2) a temperature detection step for detecting the lubricating oil temperature (t);
And based on the value of the detection output obtained in each step,
T = Ts−F (t)
Rotational torque (T) can be obtained, and the viscosity of the reaction solution can be obtained by calculation from the rotational torque (T).
That is, when calculating the rotational torque of the stirring blade according to the formula (1), an accurate rotational torque can be obtained by taking into account the change in the temperature of the lubricating oil, and the viscosity can be detected with higher accuracy. It is to become.
However, F (t) is a temperature t based on a value detected by detecting a plurality of sets by changing the temperature when the reaction liquid is empty when the temperature of the lubricating oil is t. A function regression formula.

The relational expression T = F (t) representing the torque when the temperature of the lubricating oil is t and the reaction liquid is empty will be mentioned. The function formula F (t) is based on a value detected by a plurality of sets of detected torque values when the reaction liquid is empty when the temperature of the lubricating oil is t. This is a function regression function. If the regression accuracy is high, it is not necessary to limit to a polynomial. For example, an exponential function or a rational function may be used. In any case, this function formula generally takes the form as shown in FIG. 5, and the shape of the curve varies depending on the induction motor capacity, the shape of the stirring blade, the rotational speed, and the type of lubricant of the speed reducer. In this case, the conversion error can be minimized by performing the stirring blade rotation speed at the time of actual production and using the lubricating oil of the speed reducer actually used.

Next, in the case of not using the actual rotational speed measuring instrument,
The step 1) in the step of detecting the induction motor torque Ts of the present invention is a step of detecting the rotational speed of the rotary shaft provided with the stirring blades using the induction motor as a power source. This process includes the following steps I to III.

Step I: Induction in which the loss power when the input power P is supplied is P _L , and the loss power P _L includes a loss power A that does not depend on the rotation speed and a loss power B that depends on the rotation speed A step of detecting the rotational speed of the electric motor, wherein the difference [P−A] between the electric power P and the lost electric power A is regarded as a primary approximate value PM ₁ of the mechanical output of the induction motor, and is known for the induction motor. A step of obtaining a primary approximate value N ₁ = N _S (1−S ₁ ) (N _S is a motor constant) of the rotational speed from a relational expression PM ₁ = κS ₁ (κ is a motor constant) between the output PM and the slip S. _NS is an electric motor constant called a synchronous speed.

Step II: A step of obtaining the loss power B ₁ based on the primary approximate value N ₁ obtained in Step I.

Step III: Considering the second-order approximate value PM ₂ of the output of the motor as P− (A + B ₁ ), the relational expression PM ₂ = κS ₂ between the known output PM and the slip S for the motor (κ is a motor constant) ) To obtain the second order approximate value N ₂ = N _S (1−S ₂ ) (N _S is a motor constant) of the rotation speed. Here, the obtained N ₂ is treated as a second order approximation of the detected rotational speed.

[Slip S and machine output PM]
Hereinafter, step I will be described in detail.

As is well known, the slip S is specified by the following equation (1), where N _S is the synchronization speed and N is the rotation speed of the rotor (actual rotation speed of the induction motor).

S = (N _S −N) / N _S (1)
When equation (1) is solved by N, equation (1 ′) is obtained.
N = N _S (1−S) Formula (1 ′)
That is, if the slip S can be specified, the rotational speed of the induction motor can be obtained. Therefore, the present inventor decided to use the slip S to obtain the rotation speed of the induction motor. The slip S is a basic characteristic provided with the induction motor.

The relationship between the slip S and the machine output PM is shown in FIG. 1, but the slip S and the machine output PM are within the range of the rated machine output PM ₀ and the rated slip S ₀ , that is, in operation below the practical rated speed. Are substantially proportional and have a linear relationship, and the following equation (2) holds.
In this equation (2), κ is a constant inherent to the induction motor, and is given as a ratio PM ₀ / S ₀ of the rated mechanical output PM ₀ to the rated slip S ₀ .
Therefore, if the machine output PM is known, the slip S can be obtained, and further the rotational speed (or angular speed) can be obtained.
PM = κ × S Equation (2)

By the way, since the input power P to the induction motor is consumed as a loss (loss power) in addition to the machine output PM by the induction motor, the following expression (3) is established.
PM = P−P _L Formula (3)
Here, the loss P _L of the induction motor, the primary copper loss, a secondary copper loss, iron loss, it is known to consist of mechanical loss, and floating loss. The primary copper loss is a loss caused by Joule heat due to the electrical resistance of the stator winding, and the secondary copper loss is a loss caused by Joule heat due to the electrical resistance of the rotor winding. Further, the iron loss is composed of hysteresis loss and eddy current loss, both of which are caused by the generation of a rotating magnetic field. Further, the mechanical loss is a loss due to friction and air resistance caused by the rotation of the shaft, and the floating loss is an intrinsic loss determined by the induction machine and is treated as a constant. Losses other than floating loss can be obtained by calculation using the voltage, current, power supply frequency, rotation speed, and electric circuit constants when the induction electric machine is operated (Patent Document 1, paragraph [0028] to [0040]). The elements of each loss are shown below.

[Element of loss _{P L]}
Primary copper loss: ∝ (Primary current I ₁ ) ²
Eddy current loss: ∝ (primary voltage V) ²
Hysteresis loss: ∝ (primary voltage V) ² / (frequency f)
Secondary copper loss: ∝ (secondary current I ₂ ) ² → φ (I ₁ , V, ω)
Mechanical loss: ∝ (Angular velocity ω)
Floating loss: constant

Each component of the above loss P _L can be classified into those that do not depend on the rotational speed (angular velocity omega) and (independent loss component A) to be dependent and (depending loss component B). And the non-dependent loss component A can be specified with the current measuring device and the voltage measuring device with which patent document 1 is provided. Therefore, Expression (3) can be expressed as Expression (3 ′).

PM = P− (A + B) (formula (3 ′))
[Independent loss component A] Primary copper loss, eddy current loss, hysteresis loss, floating loss [dependent loss component B] Secondary copper loss, mechanical loss

Therefore, the dependent loss component B is excluded (B = B ₀ = 0), and the first approximate value PM ₁ of the machine output PM is obtained by the following equation (4) considering only the independent loss component A as the loss power. Can do.
PM ₁ = PA ... Formula (4)
Thus, since the machine output (primary approximation value) is obtained, the primary approximation value S ₁ of the slip is obtained by the following equation (5) by applying the above equation (2).
S ₁ = PM ₁ / κ = PM ₁ × S ₀ / P ₀ (5)
Further, by applying the expression (1 ′), the first approximate value N ₁ of the rotational speed corresponding to the _first approximate value S ₁ of the slip can be obtained by the following expression (6). Here, _{N S} is the synchronous speed.
N ₁ = N _S (1−S ₁ ) (6)

The above is description corresponding to step I of the present invention, and hereinafter, steps II and III of the present invention will be described. Note that first order approximation value N ₁ of the rotational speed obtained in step I by the use purpose can be handled as a detection result of the rotation speed.

In step II, the primary approximate value B ₁ of the dependent loss component corresponding to the primary approximate value N ₁ of the rotational speed obtained in step I is obtained from a known relational expression obtained by analysis of an equivalent circuit of the induction motor by φ ( N ₁ )

In the subsequent step III, a second-order approximation value PM _{2 of the} machine output obtained by substituting the first-order approximation value B ₁ of the non-dependent loss component A and the dependence loss component into the equation (3) is given by the following equation (7). It is done. Further, similarly to the first-order approximation process, the second-order approximation value N ₂ of the rotation speed can be obtained through the equations (8) and (9). Although this secondary approximation value N ₂ is a secondary approximation value B ₁ , the dependence loss component is taken into consideration, and therefore, the accuracy with respect to the actual rotational speed is higher than that of the primary approximation value N ₁ .
PM ₂ = P− (A + B ₁ ) (7)
S ₂ = PM ₂ / κ = PM ₂ × S ₀ / P ₀ (8)
N ₂ = N _S (1-S ₂ ) (9)

  As described above, the primary approximate speed is obtained in Step I, the power loss depending on the rotational speed corresponding to the speed is obtained in Step II, and the secondary power is obtained by incorporating the power loss in the total power loss in Step III. Find approximate speed.

To obtain a tertiary approximate rate from the secondary approximation speed replaces the first order approximation speed N ₁ of the preceding returns to Step II in quadratic approximation speed N _2, determine the power loss B ₂ corresponding to speed at this time. Incorporating dependent loss component B ₂ obtained in the next step III step II the overall power loss may be calculated rotational speed corresponding thereto.

The procedure of going from tertiary to quaternary can also be performed by repeating Step II and Step III in the same manner.
The more numerous the number of the repetitions in the present invention, the value of the power loss P _L is that approaches the true value, the rotation speed obtained thereby even approaches the more accurate value. However, the present invention does not make it an essential requirement to increase the order. As shown in the examples described later, the purpose of rotational speed detection can be sufficiently achieved by the secondary approximate speed.

The general formulas for the nth order approximate machine output, the nth order approximate rotation speed, and the nth order approximation dependent loss component are as follows.
_{PM n = P- (A + B} (n-1)) ... n order approximation machine output _{N n = N S (1-} S n) ... n order approximation rotational speed _{B n = φ (N n)} ... n order approximation dependent loss Component In the above general formula, n is an integer of 1 or more, and B ₀ is considered to be zero.

Step 2) in the step of detecting the induction motor torque Ts of the present invention is a step of detecting the rotational torque of the stirring blades using the induction motor as a power source.
Here, the induction motor torque Ts, using the angular velocity (omega) of the rotating shaft of the induction generator and the input power P and the power loss P _L, can be obtained by the following expression.
Ts = (P−P _L ) / ω: Formula (10)
Further, the formula (10), 1) is expressed using a quadratic approximation value in the step _{Ts = (P- (A + B} 1)) / (2π × N 2/60) ... the formula (10-1).

[Viscosity measurement]
The viscosity detection method according to the present embodiment is based on the relational expression F (t) representing the torque when the reaction liquid is empty when the temperature of the induction motor Ts and the temperature of the lubricating oil is t. Formula T = Ts−F (t)
Rotational torque T is obtained by the following equation (11)
η = αT / N (unit Pa · S) Equation (11)
To determine the viscosity η.
Here, κ is a proportional constant determined by a reaction kettle, a stirring blade, or the like. When the viscosity detection purpose is a relative change (not an absolute value), it may be handled as κ = 1.

[Input power P (W)]
In the present embodiment, the input power P is required to obtain the rotational torque Ts of the induction motor.
As the input power P, an input power measurement value is used. A known power meter can be used for the measurement. The power meter needs to be properly used depending on the type of induction motor used. For example, when the induction motor is a single-phase circuit, a single-phase power meter, and when it is a three-phase induction motor, it is for three-phase. Use a wattmeter.

[Power Loss P _L (W)]
There is also a need for power loss P _L in order to determine the torque Ts of the induction motor.
As described above, the power loss P _L includes primary copper loss (∝ (primary current I ₁ ) ² ), eddy current loss (∝ (primary voltage V) ² ), hysteresis loss (∝ (primary voltage V) ² / ( Frequency f)), secondary copper loss (∝ φ (I ₁ , V, ω)), mechanical loss (∝ (angular velocity ω)) and floating loss (constant).
[Independent loss component A (W)]
Among these, primary copper loss, eddy current loss, and hysteresis loss depend on measured values obtained from current measuring instruments that measure current, voltage measuring instruments that measure voltage, and frequency measuring instruments that measure inverter output frequency. Calculated. More specifically, it can be obtained by performing a predetermined calculation using a voltage value, a current value and a frequency during rotation driving, and a circuit constant unique to the induction motor. Here, the circuit constant can be obtained from a test table provided by an electric motor manufacturer or from a measurement value obtained by a load test of a dielectric motor. The floating loss is provided as a value (fixed loss (unit W)) inherent to the dielectric motor.

The primary copper loss, eddy current loss, and hysteresis loss are each expressed by the following general formula.
Primary copper loss = Primary winding resistance x (Single phase current) ² x Phase formula of dielectric motor Eddy current loss = Eddy current loss when operating at rated voltage x (Measured value of single phase voltage / rated phase voltage) ² (Unit W )
Hysteresis loss = Hysteresis loss during operation at the rated voltage and rated frequency x (Measured phase voltage / Rated phase voltage) ² / (Measured inverter output frequency / Rated frequency) (Hz)

[Dependent loss component B _n (W)]
On the other hand, the secondary copper loss and the mechanical loss are components that depend on the rotational speed of the dielectric motor, and the above-described dependency loss component _Bn can be used. However, since the dependent loss component B _n is not obtained at the stage of obtaining the primary approximate rotational speed N ₁ , the loss power P _L includes only the independent loss component A, but after the second approximation, the loss power P _L Includes dependent loss components B ₁ , B ₂ ... In addition to the independent loss component A.

The dependent loss secondary copper loss which is a component B _n and mechanical loss can also be obtained in addition to the above, the n-order approximate speed N _n. That is, the secondary copper loss and the mechanical loss have the angular velocity ω as a variable. Since the angular velocity ω is in a relationship of the rotational speed N and ω = 2πN (rad / s), the n-order approximate rotational speed N _{n is changed} to the secondary copper. By substituting into the respective relational expressions of loss and mechanical loss, secondary copper loss and mechanical loss can be obtained.

[Mechanical output PM (W), Rotational torque Ts (N · m)]
The mechanical output PM is a value obtained by subtracting each loss power from the input power P. In the present embodiment, as described above, it is obtained by the general formula: PM _n = P− (A + B _(n−1) ).

Therefore, the rotational torque Ts of the dielectric motor is obtained by the above-described equation (10) also using the n-th order approximate rotational speed Nn described above, and the obtained rotational torque T _n and the n-th order approximate rotational speed N _n are used as described above. The viscosity η of the liquid material can be obtained as follows using the equation (11).
Ts _n = (P−P _L ) / ω = PM _n / ω _n = PM _n / (2π × N _n / 60) Equation (10-2)

By the way, the torque obtained in this way naturally changes in value due to a large change in the viscosity resistance of the lubricating oil of the lubricating oil type reduction gear depending on the environmental temperature and operation time, so that it is expressed as a universal physical property expression. It is very inconvenient. Therefore, even if the temperature of the lubricating oil of the lubricating oil type reduction gear is measured for each reactor manufactured by the manufacturing apparatus, and the viscosity resistance of the lubricating oil of the lubricating oil type reduction gear varies greatly depending on the environmental temperature and operating time. It is necessary to convert to a value based on the temperature of the lubricating oil.

Therefore, a relational expression T = F (t) representing torque when the reaction liquid is empty when the temperature of the lubricating oil is t is introduced, and when the temperature of the lubricating oil during operation is t. In order to convert it into a value, Equation (10-2) is rewritten as follows.
_{T n = Ts n - F (} t) ... formula (10-3)
_{T n = PM n / (2π} × N n / 60) - F (t) ... formula (10-4)
The reaction product viscosity can be determined from the torque thus determined as follows.
η _n = αT _n / N _n (unit Pa · S) Equation (11)
Here, α is a constant determined by the structure of the stirring blade.

Hereinafter, reference will be made to Equation (11).
According to Newton's equation, the force F generated when two planes of area A sandwiching a liquid of thickness h move at a relative speed U is expressed by the following equation (12 ).
F = ηAU / h (unit: N) Expression (12)
Here, in the reaction vessel shown in FIG. 2, r is the stirring blade radius, L is the length of the stirring blade immersed in the liquid material to be stirred, N is the number of rotations, and F is the stirring blade at the distance r. Assuming that the force, g, generated in the above equation represents the distance between the stirring blade and the reaction kettle, the above equation (12) is expressed as the following equation (13).

F = η (2πrL · 2πrN) / g (13)
Therefore,
Rotational torque (T) = F · r = η (2πrl · 2πrN) / g · r (unit: N · m)
So
η = T · g / (2πrl · 2πrN · r).

However, since the constants other than T and N are constants determined by the dimensions of the reaction vessel and the stirring blade, when this is expressed as α, the viscosity η is expressed as in Equation (11). In particular, the viscosity of the liquid material can be determined.
η = αT / N Equation (11)

  In the present embodiment, the output frequency may be measured synchronously with other measurement quantities such as power, voltage, and current, and incorporated into various variables for determining the loss. In the present embodiment, by incorporating a frequency measurement value for detecting the inverter output frequency into the hysteresis loss detection, it is possible to reduce the variation (variation) in the detected reaction liquid viscosity. This is preferable.

[Synchronous measurement]
In this embodiment, when the load time fluctuation is fast, the measurement timing shift in each measuring instrument breaks the premise of the energy conservation law that the sum of input and output of energy becomes zero. Are preferably performed synchronously. However, this is not the case when it can be said that the measured values do not change substantially until all the measured values have been collected since the fluctuation of the load is moderate.

  In addition, when the load fluctuates over time, in addition to the measuring instruments, there is a synchronization signal generating means for issuing measurement commands to all the measuring instruments at the same time. It can be made to be.

  The specific application to which the rotational speed and rotational torque detection method according to the present embodiment is applied is not limited, and an example is viscosity detection of a reaction solution. Since the viscosity of the reaction liquid varies according to the progress of the reaction, the progress of the reaction can be grasped by detecting the viscosity. In this case, it is an apparatus for detecting the rotational speed and rotational torque of the shaft using the dielectric motor as a power source, and further detecting the viscosity of the reaction solution, and a power meter for measuring the power supplied to the dielectric motor, A current measuring device for measuring current, a voltage measuring device for measuring voltage, and a frequency measuring device for measuring an inverter output frequency are provided. And it comprises an arithmetic processing part which calculates | requires a rotational speed and a rotational torque by performing a predetermined calculation based on the measurement information obtained by each means, and also calculates | requires the viscosity of a liquid substance by a calculation. As each measuring instrument for power, voltage, current, and frequency, a known and commonly used measuring instrument can be used.

  For the arithmetic processing unit, various types of personal computers such as notebook computers and desktop computers, or means having a known and commonly used arithmetic processing function such as a process computer can be used. Between these arithmetic processing units and each measuring instrument, there may be a known and common data communication function such as RS-232C, GP-IP, USB, ISA, PCI, etc., and the above-mentioned synchronization signal generating means is a computer. It may be substituted by an instruction from the etc.

Hereinafter, an example of the detection apparatus 1 that executes the rotational speed (rotational torque, viscosity) detection method according to the present embodiment will be described with reference to FIG.
The detection device 1 detects the rotational speed of a stirring blade 13 in which a liquid substance, for example, a chemical reaction product charged into the reaction kettle 12 is rotationally driven by an induction motor 9.
The detection device 1 includes a measurement unit 2 and an arithmetic processing unit 5.

  The measuring unit 2 is a package in which a total of four functions of a power meter, a voltmeter 4 channel, an ammeter 4 channel, and a frequency meter in a three-phase AC circuit are combined into one unit. 6 and a current lead-in wire 7 are connected to a three-phase AC circuit. In addition, it cannot be overemphasized that the measuring part 2 may be provided with each measuring device separately.

  FIG. 3 assumes that the induction motor 9 that is a power source of the stirring blade 13 is a three-phase circuit, and that a known and commonly used three-phase wattmeter should be used. It goes without saying that both the voltage and current are measured for each phase, and the calculation for calculating the rotation speed is also performed for each phase. Further, the present invention can be similarly applied even when the target induction motor is a single-layer circuit or a DC motor driven by a DC power source.

  The arithmetic processing unit 5 is composed of, for example, a personal computer, controls the operation of the measuring unit 2, acquires the power value, the voltage value, the current value, and the frequency measured by the measuring unit 2, and the above-described induction motor 9 The calculation process for obtaining the rotation speed and the rotation torque is performed, and the calculation process for obtaining the viscosity of the liquid material is performed based on the result.

  In the measurement unit 2, the measurement in each measuring instrument is performed simultaneously and synchronously by a command from the arithmetic processing unit 5 via the communication cable 8. The arithmetic processing unit 5 holds information necessary for arithmetic processing such as a calculation process for obtaining the rotational speed, rotational torque, viscosity of the reaction liquid, and fixed loss of the induction motor 9, and the measurement information includes An operation for calculating the rotation speed is performed based on the result, and the result is output to a screen, an internal information recording means, or the like.

The induction motor 9 is connected to a stirring shaft 11 via a speed reducer 10, and a stirring blade 13 is attached to the stirring shaft 11. Further, a lubricating oil speed reducer 16 is attached between the rotation shaft of the induction motor 9 and the rotation shaft provided with the stirring shaft 11. The stirring blade 13 is disposed in the reaction kettle 12 and stirs the reaction object charged into the reaction kettle 12 according to the rotation of the induction motor 9. The induction motor 9 is supplied with power from the three-phase power supply 15 via the inverter 14.

According to the detection apparatus 1 having the above configuration, the operator can know the rotational speed value, the rotational torque value, and the viscosity of the reaction liquid displayed on the monitor screen of the arithmetic processing unit 5 in real time.
In addition, since the rotational speed detection in the present invention is performed using the linearity of the motor output and the high slip, the error becomes large in a large output region (exceeding the rated output) where the linearity is lost. However, in the industrial use of dielectric motors, especially in the resin manufacturing process involving chemical reactions, the majority of dielectric motors are used below the rated output, and even around 50% of the rated output. There is almost no problem.

[Temperature resistance compensation]
By the way, although the value of winding resistance is used when calculating | requiring a primary copper loss, the value at a reference temperature (20 degreeC) is normally provided for winding resistance. Therefore, in obtaining the primary copper loss, the detection accuracy of the rotational speed, and consequently the rotational torque and the viscosity of the reaction liquid can be further increased by using the value corrected with the actual operating temperature.
Since this temperature correction may be performed according to the procedure described in Patent Document 1, the reprinting here is omitted. The same applies to the correction of the empty torque, the temperature correction of the viscosity, and the correction of the charged amount of the viscosity described below, and the re-display here is omitted.

[Empty torque correction]
The torque obtained by the equation (10) includes the empty torque which is a component that is generated such as mechanical friction of the speed reducer and the bearing even when the contents of the reaction kettle are empty. The empty torque includes the viscous resistance of the reducer's lubricating oil, which varies greatly depending on the environmental temperature and operating time, and the reaction liquid is empty when the temperature of the lubricating oil at the time of manufacture is t. Is detected in advance, this is treated as a variable, and the viscosity detection accuracy can be further improved by subtracting the variable from the induction motor torque Ts as shown in Equation (1) when determining the viscosity.

[Temperature correction of viscosity]
Generally, since the reaction temperature is determined for each product, the reaction kettle is provided with a temperature control function. This correction is not necessary when the viscosity effect of temperature control error can be ignored, but in reality an error of about ± 1 to 3 ° C is unavoidable, so it is corrected to a value at a predetermined temperature (standard reaction temperature). If the measured value is used, the detection accuracy can be increased.

[Correction of viscosity charge amount]
Further, in this embodiment, when the standard charge amount per production unit in a predetermined reaction kettle is different from the actual charge amount in the production unit, the reaction solution viscosity value is calculated based on the difference between the charge amounts of both. By correcting, detection accuracy can be increased.

Hereinafter, the example which applied this invention to manufacture of the reaction liquid containing a polyurethane resin is demonstrated. In addition, the apparatus shown in FIG. 3 was used for manufacture of this reaction liquid. The specifications of the induction motor 9 are as follows.
Specification of three-phase induction motor (Y connection) Capacity: 22kW Rated speed: 975 revolutions per minute (rated slip 0.025)
Rated voltage: 200V Rated current: 79A Rated frequency: 50Hz
Number of poles: 6
Primary winding resistance: 0.0358Ω
Primary winding reactance: 0.2010Ω (at rated frequency)
Secondary winding resistance: 0.0310Ω
Secondary winding reactance: 0.1797Ω (at rated frequency)
Resistance measurement reference temperature: 20 ° C. Resistance temperature coefficient: 234.5
Mechanical loss: 130W (at rated speed)
Iron loss: 650 W (design values: hysteresis loss 350 W, eddy current loss 300 W)
Floating loss: 110 W Stirring shaft reduction ratio: 16.7: 1

  The product in this example is a polyurethane resin product obtained by promoting the polymerization reaction by dilutely adding toluene diisocyanate (2,4: 2,6 = 95 or more: 5 or less) to diethylene glycol. The reaction temperature in this example is 80 ° C., and the charged amount is 4500 kg.

  In the comparative example, a polyurethane resin was produced by the method shown in Patent Document 1 using the same raw materials and reaction conditions as described above.

  The measurement unit 2 shown in FIG. 3 used in the example uses a remote measurement monitoring system 2300 (Hioki Electric). This measuring instrument incorporates four functions of a power meter, a voltmeter, an ammeter, and a frequency meter of a three-phase AC circuit into one unit by appropriately selecting a measuring module. Any other measuring instrument can be used as long as it has the same measuring function.

  The arithmetic processing unit (PC) 5 obtains data from the measuring unit 2 through communication means, performs a predetermined calculation to calculate the rotational speed and rotational torque, and sends a measurement timing signal to each measuring means all at once. Also serves as a synchronizing signal generating means. Each measuring means measures a predetermined number of times per unit time at the same time in response to a command from the arithmetic processing unit 5, and the arithmetic processing unit 5 takes in the average value to calculate the rotational speed, rotational torque, and viscosity.

FIG. 4 shows the rotational speed (secondary approximate value N “1” in FIG. ₂ ) and the actual rotational speed (“2” in the figure) obtained in the process 1) in the process of obtaining the induction motor torque Ts. A rotation speed chart is shown. From this figure, it can be seen that the rotational speed detected in the present embodiment has a small difference from the actual rotational speed and reflects the actual rotational speed.

  Further, in this example, the relational expression T = F (t representing the torque when the reaction liquid is empty when the temperature of the lubricating oil is t in the method of detecting the viscosity of the reaction liquid of the present invention. ) Was obtained by regression from the graph showing the relationship of torque when the temperature of the lubricating oil in FIG. 5 is t when the reaction solution is empty.

T = 690.38 * EXP (−0.010 * t).
In this functional equation, for example, the idling torque when the temperature of the lubricating oil is t = 30 ° C. is 511 Nm.

FIG. 6 shows a correlation analysis with the viscosity of the reaction liquid detected by applying Patent Document 1. As shown in FIG. 6, the viscosity detected by the procedure of Patent Document 1 shows a tendency that the viscosity increases as the temperature of the lubricating oil decreases. As the temperature change of the lubricating oil increases, the viscosity varies. Can be read (contribution rate 0.53). On the other hand, FIG. 7 shows a correlation analysis with the viscosity of the reaction liquid detected by applying the present invention, and takes into account the viscosity resistance of the lubricating oil that varies depending on the environmental temperature and operating time. It can be seen that the variation in viscosity is small as the temperature change of the lubricating oil becomes large (contribution rate 0.91).

  In addition, the notation of the viscosity unit in FIG. 6 uses rPa.S for the sake of convenience, with the prefix r added, in order to distinguish it from what is output from a calibrated general viscometer. The relative viscosity represented by rPa.S is numerically unique to the stirring system composed of an electric motor, a speed reducer, and a stirring blade. Therefore, if the stirring system changes, the value increases or decreases as a whole. There is a thing. However, there is no problem in detecting the relative change in viscosity in the system.

As described above, the present invention takes into account the viscous resistance of the lubricating oil that varies depending on the environmental temperature and operating time without providing a large-scale conventional apparatus in an explosion-proof area such as a chemical factory, and therefore, more accurate. The viscosity can be obtained from the rotational torque T, and an unbiased viscosity evaluation can be performed.
In addition, as a result of intensive studies by the inventor, the present invention is not limited to detecting and applying the temperature of the lubricating oil, and detects the ambient outside air temperature or the surface temperature of the speed reducer, Since the same effect can be obtained by applying the temperature of the lubricating oil to the present invention instead of the temperature of the lubricating oil, the ambient outside air temperature and the surface temperature of the speed reducer are allowed.

DESCRIPTION OF SYMBOLS 1 Detection apparatus 2 Measurement part 5 Arithmetic processing part 9 Induction motor 12 Reaction kettle 13 Stirring blade 14 Inverter 15 Three-phase power supply 16 Lubricating oil temperature

Claims (7)

A reactor that stirs the reaction liquid by rotating a rotating shaft provided with a stirring blade using an induction motor as a power source; and
A rotating shaft of the induction motor;
Between the rotating shaft provided with the stirring blade, a lubricating oil type speed reducer that reduces the rotation speed of the induction motor is installed.
In the reactor,
A method for detecting the viscosity of the reaction solution,
1) Induction motor torque (Ts) detection process,
2) a temperature detection step for detecting the lubricating oil temperature (t);
Each process,
The viscosity of the reaction solution is
From the induction motor torque Ts, the equation (1)
T = Ts−F (t) Equation (1)
To obtain the rotational torque (T),
Further, a calculation step for calculating the viscosity of the reaction liquid from the rotational torque by calculation,
The viscosity detection method of the reaction liquid characterized by comprising.
(However, F (t) is a temperature t based on a value detected by a plurality of sets of detected torque values when the temperature of the lubricating oil is t when the reaction liquid is empty. (It is an equation obtained by regression with function.) The step of obtaining the induction motor torque Ts
1) Power detection step for detecting power supplied to the induction motor 2) Current detection step for detecting current supplied to the induction motor 3) Voltage detection step 4) for detecting voltage supplied to the induction motor Rotational speed detection step of detecting the speed of the rotating shaft of the induction motor 5) Each step of the frequency detection step of detecting the power supply frequency of the induction motor,
The value (P) obtained in the power detection step;
From the loss power (P _L ) generated in the induction motor and the rotational shaft angular velocity (ω), the following equation (2)
Ts = (P−P _L ) / ω Equation (2)
The method for detecting a viscosity of a reaction solution according to claim 1, wherein: The step of obtaining the induction motor torque Ts
The method for detecting a viscosity of a reaction solution according to claim 1, comprising the following steps.
1) the power loss when the input power P to the induction motor is supplied with P _L,
The power loss PL is _divided into power loss A that does not depend on the rotational speed of the rotating shaft of the induction motor and power loss B that depends on the rotational speed.
The difference between the input power P and the loss power A is a first-order approximate value PM of the mechanical output of the induction motor.
₁ and the relational expression PM ₁ between the output PM and the slip S known for the induction motor =
From αS ₁ (α is a motor constant), a first-order approximate value N ₁ = N _S (1-S ₁
) (N is a synchronization speed)
Step II for determining the power loss B ₁ based on the primary approximation N1;
Considering the second-order approximate value PM ₂ of the output of the induction motor as P− (A + B ₁ ),
The relational expression PM ₂ = αS ₂ between the output PM and the slip S which are known for the induction motor.
A rotational speed detecting step including step III for obtaining a second order approximate value N ₂ = N _S (1−S ₂ ) (N _S is a motor constant) of the rotational speed of the rotating shaft from (α is a motor constant).
2) Based on the input power P, the lost power A, the lost power B ₁ obtained in Step I of the rotational speed detection step, and the second order approximate value N ₂ of the rotational speed obtained in Step III. ,
Formula (3)
_{Ts = (P- (A + B} 1)) / (2π × N 2/60) (3)
Rotational torque detection step for obtaining the induction motor torque Ts by An induction motor as a power source, installed in a reactor that stirs the reaction liquid by rotating a rotating shaft equipped with a stirring blade; and
A rotating shaft of the induction motor;
Between the rotating shaft provided with the stirring blade, a lubricating oil type speed reducer that reduces the rotation speed of the induction motor is installed.
An apparatus for detecting the viscosity of the reaction solution,
The apparatus has 1) a means for detecting the induction motor torque (Ts), 2) a temperature detecting means for detecting a lubricating oil temperature (t), and
The viscosity of the reaction solution is
From the induction motor torque Ts, the equation (1)
T = Ts−F (t) Equation (1)
To obtain the rotational torque (T),
Further, calculation means for calculating the viscosity of the reaction liquid from the rotational torque by calculation,
A viscosity detector for reaction liquid, comprising:
(However, F (t) is a temperature t based on a value detected by a plurality of sets of detected torque values when the temperature of the lubricating oil is t when the reaction liquid is empty. (It is an equation obtained by regression with function.) Means for obtaining the induction motor torque Ts are:
1) Power detection means for detecting the power supplied to the induction motor 2) Current detection means for detecting the current supplied to the induction motor 3) Voltage detection means 4) for detecting the voltage supplied to the induction motor Rotation speed detection means for detecting the speed of the rotating shaft of the induction motor 5) Each means of frequency detection means for detecting the power supply frequency of the induction motor,
The value (P) obtained by the power detection means;
From the loss power (P _L ) generated in the induction motor and the rotational shaft angular velocity (ω), the following equation (2)
Ts = (P−P _L ) / ω Equation (2)
The viscosity detector for a reaction liquid according to claim 4, wherein: Means for obtaining the induction motor torque Ts are:
The apparatus for detecting a viscosity of a reaction liquid according to claim 4, comprising the following means.
1) the power loss when the input power P to the induction motor is supplied with P _L,
The power loss PL is _divided into power loss A that does not depend on the rotational speed of the rotating shaft of the induction motor and power loss B that depends on the rotational speed.
The difference between the input power P and the loss power A is a first-order approximate value PM of the mechanical output of the induction motor.
₁ and the relational expression PM ₁ between the output PM and the slip S known for the induction motor =
From αS ₁ (α is a motor constant), a first-order approximate value N ₁ = N _S (1-S ₁
) (N _S is the synchronization speed)
Step II for determining the power loss B ₁ based on the primary approximation N ₁ ;
Considering the second-order approximate value PM ₂ of the output of the induction motor as P− (A + B ₁ ),
The relational expression PM ₂ = αS ₂ between the output PM and the slip S which are known for the induction motor.
Rotational speed detection means including step III for obtaining a second order approximate value N ₂ = N _S (1−S ₂ ) (N _S is a motor constant) of the rotational speed of the rotating shaft from (α is a motor constant).
2) Based on the input power P, the loss power A, the loss power B ₁ obtained in Step I of the rotation speed detection means, and the second order approximate value N ₂ of the rotation speed obtained in Step III. ,
Formula (3)
_{Ts = (P- (A + B} 1)) / (2π × N 2/60) (3)
Rotational torque detection means for obtaining the induction motor torque Ts by The viscosity detection device according to any one of claims 4 to 6, wherein the reaction liquid contains a polyester resin, an acrylic resin, a polyurethane resin, an epoxy resin, a phenol resin, or a resin for varnish. A reaction liquid generator.

Images