JP2967701B2 - Viscosity measuring device and method for measuring viscosity using static mixer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a viscosity measuring device and a viscosity measuring method for a fluid, and more particularly to a viscosity measuring device and a viscosity measuring method for measuring a viscosity of a fluid from a pressure difference of a fluid passing through a pipe.

[0002]

2. Description of the Related Art Conventionally, viscosity measurement methods for calculating the viscosity of a fluid include an orifice method, a resistance plate (shear force measurement) method,
And rotary cylinder type.

FIGS. 7 to 9 are explanatory diagrams showing the main configuration of an apparatus utilizing these methods.

Referring to FIG. 7, the orifice system is a system in which an orifice (small tube) is provided in a pipe through which a fluid flows, and the viscosity of the fluid is calculated from a pressure difference between upstream and downstream of the orifice. The viscosity measurement range of the orifice method is approximately 1 to
It is about 1000P (poise).

Referring to FIG. 8, in the resistance plate method, a resistance plate 101 is inserted into a fluid flowing through a pipe, and the resistance plate 101 is inserted.
Is a method of calculating the viscosity of the fluid from the pressure of the fluid applied to the fluid. The higher the viscosity, the greater the shear force applied to the resistance plate. The viscosity measurement range of the resistance plate method is about 30 cP (centipoise) to 2000 P (poise).

Referring to FIG. 9, in the rotating cylinder system, a rotating cylinder 102 is inserted into a fluid flowing through a pipe, and a rotating cylinder 101 is inserted.
In this method, the viscosity of the fluid is calculated from the pressure of the applied fluid. When the rotating cylinder 102 is rotated by an external power source, different torques are applied to the rotating cylinder depending on the magnitude of the viscosity. The viscosity is calculated by detecting this torque. The viscosity measurement range of the rotating cylinder method is about 1 cP (centipoise) to 1500 P (poise).

As described above, the orifice method measures the viscosity from the fluid pressure loss, and the resistance plate method and the rotary cylinder method measure the viscosity from the fluid pressure.

Japanese Patent Publication No. 6-19318 proposes such an orifice type viscosity measuring device. FIG.
FIG. 1 is a sectional view for explaining a conventional orifice type viscosity measuring device as proposed in Japanese Patent Publication No. 6-19318.

Referring to FIG. 10, in an orifice type viscosity measuring device, a main pump 72 is flange-coupled to a lower portion of a pipe 71, and the main pump 72 is fitted so as to rotate integrally with a drive shaft 76. The gear pump is provided with a gear 75, which is housed in a pump chamber 74 in a housing 73, and has a suction port above the gear 75 and a discharge port below the gear 75. The gear 75 is rotated at a constant speed by an external drive source 77. This rotation speed is detected by a rotation speed detector 90. The metering pump 81 is a gear pump having a gear 82 connected via a shaft coupling 80 so as to rotate integrally with the drive shaft 76. The gear 82 is housed in the metering pump chamber and sucked below the gear 82. Port 84, discharge port 86 above
It has. The discharge port 79 side of the main pump 72 and the suction port 84 of the metering pump 81 are connected through a flow path 85, and the discharge port 86 of the metering pump 81 and the suction port 78 of the main pump 72 are connected.
The side is connected through an orifice 88 and a flow path 87.

In such an apparatus, a fluid is supplied from a pipe 71, and the fluid is introduced from a flow path 85 on the discharge port 79 side of the metering pump to the metering pump 81 side. And
Fluid is pumped from a metering pump inlet 84 via a gear 82 to a metering pump outlet 86 and an orifice 88
, A large pressure loss occurs here, and the pressure is returned to the flow path 87 communicating with the suction port 78 side of the metering pump. The pressure on the upstream side of the orifice is detected by the pressure gauge 89, and the pressure on the downstream side is regarded as the atmospheric pressure (or the pressure of the fluid in the pipe 71).
Therefore, the viscosity is calculated from the difference between the pressure indicated by the pressure gauge 89 on both sides of the orifice and the atmospheric pressure (or the pressure of the fluid in the pipe 71).

When measuring the viscosity of a non-Newtonian fluid whose viscosity changes according to the shear rate of the fluid, the external drive source 7
7, the flow rate is changed by changing the rotation speed of the gear 82, and the viscosity at a predetermined shear rate is extrapolated and obtained.

[0012]

However, all of the conventional viscosity measurement methods have a dead space (a region in which the fluid stays) in the flow path of the fluid to be measured, and therefore have poor sanitation properties. It cannot be used for plants that require sanitization. And this dead space may affect a viscosity value.
In addition, it is difficult to connect in-line to the plant piping. In addition, since the number of components constituting the viscosity measuring device is large, the entire device is enlarged and complicated.

In the orifice system, the orifice itself has a simple structure. However, referring to FIG. 10, the entire apparatus for introducing a fluid and generating a pressure difference has a very complicated structure, and furthermore, a dead space is provided near the orifice. And the disadvantage that the orifice is easily clogged. Therefore, it is difficult to provide an orifice type viscosity measuring device in-line. Moreover, the orifice method is not suitable for measuring the viscosity of highly viscous fluids.

The resistance plate method has a dead space in the vicinity of the resistance plate (especially immediately below the resistance plate) and requires a space for disposing the resistance plate. In addition, the durability of the device is inferior due to having a movable member called a resistance plate. In addition, it is not suitable for measuring the viscosity of a fluid (non-Newtonian fluid) whose viscosity changes due to shear force.

In the rotary cylinder system, a dead space is generated in the vicinity of the rotary cylinder (particularly immediately below the rotary cylinder). In addition, a flow path (pipe) through which fluid flows and a seal for inserting the rotary cylinder is particularly required. Since the apparatus has a rotating member called a rotating cylinder, the durability of the device is poor, and an external drive source for the rotating cylinder is required. In addition, when changing the viscosity measurement range, it is basically necessary to replace the rotating cylinder, and it takes time to remove the rotating cylinder from the flow path.

In view of the above-mentioned properties of the prior art, an object of the present invention is to provide a novel viscosity measuring device and a novel viscosity measuring method based on a completely new principle or structure.

In particular, it is a specific object of the present invention to provide a viscosity measuring apparatus and a viscosity measuring method which have a high sanitary property, a simple structure, and a wide viscosity measuring range.

[0018]

In order to achieve the above-mentioned basic object, a viscosity measuring device using a static mixer according to a first aspect of the present invention is provided with a means for dividing a fixed flow into a flow path, A static mixer that mixes fluids by changing lines, pressure gauges respectively provided on the upstream side and the downstream side of the static mixer, and a viscosity of the fluid flowing through the static mixer is determined based on a pressure difference indicated by the pressure gauge. Means.

A viscosity measuring method using a static mixer according to a second aspect of the present invention includes a means for dividing a fixed flow in a flow path, and a method for mixing a fluid by changing a flow line. Flowing a fluid, measuring a pressure loss value of the fluid by a static mixer, and calculating a viscosity of the fluid based on the pressure loss value.

Preferably, in the first aspect of the present invention, the static mixer is connected in-line to a pipe through which a fluid whose viscosity is to be measured flows.

Preferably, in the first aspect of the present invention, the static mixer is connected online to a pipe through which a fluid whose viscosity is to be measured flows.

In the first aspect of the present invention, preferably, the temperature measuring means for measuring the temperature of the fluid, the flow rate measuring means for measuring the flow rate of the fluid, and the density measuring means for measuring the density of the fluid include The means for determining the viscosity, which is provided in the pipe through which the fluid to be measured flows, receives the outputs of the temperature measuring means, the flow rate measuring means, and the density measuring means as inputs.

In the second aspect of the present invention, preferably, the flow rate, density, temperature and shear rate of the fluid are measured, and the viscosity of the fluid is calculated based on the flow rate, density, temperature and shear rate of the fluid by Fanning's formula. Is obtained. In addition, please refer to "Formula 1" for the formula of Fanning.

[0024]

The viscosity measuring device and measuring method of the present invention are based on a completely new principle of using a static mixer.
That is, the viscosity is measured by a simple structure, which itself makes a remarkable technical progress. The remarkable effect is that the use of the static mixer has been expanded and its unknown potential has been realized.

With the above arrangement, in the viscosity measuring device (first aspect) of the present invention, a pressure loss is generated by passing a fluid through a static mixer, and the viscosity of the fluid is determined from the pressure loss. Since the static mixer has no moving parts inside and outside, it has high rigidity and can be made to have a simple configuration as a whole.In addition, there is no dead space in the static mixer and fluid is mixed in the static mixer. Therefore, it has high sanitary properties (cleanability). Therefore, it is particularly suitable for measuring a high-density fluid having a high fluid pressure or a high-viscosity fluid which is likely to adhere and remain in the apparatus. Furthermore, the viscosity measuring device of the present invention can appropriately select the static mixer diameter on the viscosity measuring device side according to the piping diameter of the plant to be measured, and requires a complicated and large-sized device such as an external power source. Therefore, it is easy to perform in-line measurement or online measurement by inserting in series or connecting in parallel to piping of another plant or system. Since the viscosity measurement range can be flexibly changed by changing the diameter of the static mixer, the number of elements, and the like, the measurement can be actually performed over a wide range. Further, even in the case of measuring the viscosity of a non-Newtonian fluid, accurate measurement of the viscosity is possible because the influence of the viscosity measurement on the viscosity of the fluid is very small.

As described above, according to the viscosity measuring method of the present invention (second viewpoint), since the static mixer has no movable part inside and outside, the rigid mixer has high rigidity and the entire apparatus for implementing the method is used. Has a simple configuration, has no dead space in the static mixer, and has a high sanitary property (cleaning property) because the fluid is mixed in the static mixer. Therefore, it is particularly suitable for measuring a high-density fluid having a high fluid pressure or a high-viscosity fluid which is likely to adhere and remain in the apparatus. Further, the viscosity measurement method of the present invention can appropriately select a static mixer diameter used for viscosity measurement in accordance with a pipe diameter of a plant to be measured, and requires a complicated and large-sized apparatus such as an external power source. Therefore, it is also easy to insert in series or connect in parallel to piping of another plant or system to perform in-line measurement or online measurement. Since the viscosity measurement range can be flexibly changed by changing the diameter of the static mixer, the number of elements, and the like, the measurement can be actually performed over a wide range. Further, even in the case of measuring the viscosity of a non-Newtonian fluid, accurate measurement of the viscosity is possible because the influence of the viscosity measurement on the viscosity of the fluid is very small.

[0027]

SUMMARY OF THE INVENTION In the viscosity measuring apparatus and the viscosity measuring method of the present invention, a pressure loss is generated by passing a fluid through a static mixer, and the viscosity of the fluid is determined from the pressure loss.

The static mixer is usually an in-line stirrer without a drive unit in which right-handed and left-handed helical elements are alternately arranged in a tube so that the ends thereof are perpendicular to the ends of the other elements. It is a vessel. The principle of the mixing is that the fluid passing through the static mixer is completely mixed in the radial direction by being subjected to actions such as splitting, reversing, and changing the flow by the element.

The static mixer has no driving unit,
Since the stirring driving force is only the pressure loss when the fluid passes through the static mixer, the stirring device is a compact stirrer with extremely low energy consumption, and the present invention can make use of these advantages.

In the field of mixing or stirring, the diameter of the static mixer is selected from the total flow rate and the optimum flow rate, and depending on the properties of the fluid flowing through the flow path (Reynolds number and viscosity),
The number of elements (number of baffles), diameter, length, and the like of the static mixer are appropriately selected. For example, a static mixer having a large number of elements tends to be used for mixing a highly viscous fluid. Also in the present invention, based on the above knowledge, the number of elements (number of baffles), diameter, length, etc. of the static mixer are appropriately selected according to the assumed viscosity of the fluid.

When a fluid flows through such a static mixer, a predetermined pressure loss is generated, and the viscosity is determined from a known viscosity calculation formula (Fanning's formula) based on the pressure loss.

The means for determining the viscosity of the present invention calculates the viscosity by substituting this pressure difference into a viscosity calculation formula based on at least the pressure differences indicated by pressure gauges provided upstream and downstream of the static mixer. The means for determining the viscosity of the present invention is 2
A microcomputer in which the output signals of two pressure gauges are input and a viscosity calculation formula is programmed is preferable. Further, the two pressure gauges may be configured to display a pressure value, and the operator substitutes the displayed pressure value into a viscosity calculation formula or obtains the viscosity from a chart. More preferably, the means for determining viscosity according to the present invention further comprises a microcomputer having input of output signals of the two pressure gauges and programmed with a viscosity calculation formula.
Output signals of the temperature measuring means for measuring the temperature of the fluid and the flow rate measuring means for measuring the flow rate (mass, volume) and specific gravity of the fluid are inputted, and the fluid pressure upstream and downstream of the static mixer, the mass flow rate of the fluid, The viscosity is calculated by substituting the fluid density (specific gravity) into the viscosity calculation formula. Preferably, the measured fluid temperature is input to a microcomputer, and the viscosity is calibrated based on a pre-programmed change formula of the viscosity with respect to the temperature. (Corrected).

The viscosity measuring apparatus and the viscosity measuring method of the present invention have the following advantages in addition to the above description of the “action”.

The viscosity measurement range can be flexibly changed by changing the diameter of the static mixer, the number of elements, and the like. The preferred viscosity measurement range is approximately several P
(Poise) to about tens of thousands of P (poise). Viscosity in a range exceeding this can be measured by appropriately selecting the number of elements and the like.

In the case of measuring the viscosity of a non-Newtonian fluid, the viscosity measurement device itself has very little influence on the viscosity of the fluid, so that accurate viscosity measurement can be performed.

Further, since the viscosity measuring device of the present invention has high sanitary properties as described above, it is very hygienic to apply the viscosity measuring device of this embodiment to a food production plant. Further, since the viscosity is measured more accurately and continuously, the state of the fluid can be accurately and continuously grasped based on the obtained viscosity of the fluid.

For example, when the fluid to be measured is a fermented food, the progress of fermentation can be recognized based on the obtained viscosity, so that it is not necessary to take out (sample) the food to the outside. Therefore, disturbance is not given to the internal fluid by sampling, and it is sanitary.

In addition, by using the viscosity measuring apparatus of the present invention, it is possible to configure a feedback system for controlling the supply of the raw material of the fluid whose viscosity is to be measured in accordance with the measured viscosity. Examples of the supply control device include a transfer pump that controls the supply of a fluid or the like, a feeder that controls the supply of a solid (powder) or the like, a valve that controls the supply of a gas or the like, and the like.

The viscosity measuring apparatus of the present invention can be used for measuring the viscosity of any fluid (for example, one containing air bubbles, a fluid solid, etc.), and is used for the chemical industry such as petrochemical, resin / adhesive industry, food It can be used in all fields such as industry, water treatment industry, and pulp and paper industry. In particular, it is suitable for measuring the viscosity of a fluid having a tendency to become a non-Newtonian fluid, such as an adhesive, a sticky material, or a resin.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings.

Embodiment 1 First, the configuration of a viscosity measuring device according to an embodiment of the present invention will be described.

FIG. 1 is a piping diagram showing a partial configuration of a viscosity measuring device according to an embodiment of the present invention, wherein a solid line indicates an in-line viscosity measuring device, and a dotted line indicates an on-line viscosity measuring device. Note that the space between the pipes 4a and 4b is normally closed in the case of in-line measurement. The online viscosity measuring device is connected to the online piping 4b in parallel with the in-line piping 4a.
(Bypass) is attached to measure the viscosity at the bypass portion. Arrows in the pipes 4a and 4b indicate flow directions of the fluid, respectively.

Referring to FIG. 1, the in-line viscosity measuring device includes a flow meter 1, a thermometer 2, and a static mixer 5a in order from the upstream to the downstream (in the direction of the arrow). Pressure gauge 3 on the upstream) side
a, a pressure gauge 3b is provided on the outlet (downstream) side.

The static mixer 5a is an in-line stirrer without a drive unit in which right-handed and left-handed spiral elements are alternately arranged so that the ends thereof are perpendicular to the ends of the other elements. . Since the power required for stirring is only the pressure loss when the fluid passes through the mixer, it is a compact stirrer with extremely low energy consumption.

The on-line viscosity measuring device includes a flow meter 1 and a thermometer 2 common to the in-line side in order from the upstream to the downstream (in the direction of the arrow), and a sampling pump 6 and a static mixer 5b in the middle of the pipe 4b. And a pressure gauge 3 at the inlet (upstream) side of the static mixer 5b.
a, a pressure gauge 3b is provided on the outlet (downstream) side.
The static mixer 5b has the same configuration as the static mixer 5a.

The difference between the configuration of the in-line type viscosity analyzer and that of the online type viscosity measurement device is the presence or absence of the sampling pump 6 provided upstream of the pressure gauge 3c. In addition, at least one (in-line or online) device is sufficient for the viscosity measurement, but both devices may be provided. If the viscosity measurement fluid is an incompressible fluid, the flow rate is determined by sampling.
The flow rate and fluid density do not change. If it changes, it is necessary to measure the sampling flow rate, and a flow meter is further provided upstream or downstream of the sampling line (piping 4b).

Since the static mixer is connected in-line to the pipe through which the fluid whose viscosity is to be measured flows, the viscosity measuring apparatus of the present embodiment can be reduced in size and cost, and connected online. Thus, the viscosity measuring device of the present embodiment can be easily applied to existing systems and plants.

Next, the operation of these viscosity measuring devices will be described.

In the case of the in-line measurement, first, the mass flow rate and the fluid density of the fluid flowing through the pipe 4a are measured by the flow meter 1, and the fluid temperature is measured by the thermometer 3, respectively. Next, pressure gauge 3a
As a result, the fluid pressure P0 before the inflow of the static mixer 5a is measured. Then, when the fluid passes through the static mixer 5a, pressure loss occurs depending on the structure (number of elements, diameter, and pipe diameter) of the static mixer 5a. Finally, the fluid pressure P1 flowing out of the static mixer 5a is measured by the flow meter 3b.

The on-line measurement is the same as the operation in the in-line measurement except that the fluid is sent from the sampling pump 6 for introducing the fluid from the in-line (main piping) side to the static mixer 5b side, so the description is omitted. .

From the measured values of the fluid pressures P0, P1, etc., the viscosity is calculated by means for calculating the viscosity shown in FIG. FIG. 2 is a block diagram showing a schematic configuration of the entire in-line viscosity measuring device.

Referring to FIG. 2, in the in-line viscosity measuring device, the outputs of flow meter 1, thermometer 2, and pressure gauges 3a and 3b are supplied to AD (analog / digital) conversion circuit 13 at flow rate F0 (mass flow rate or mass flow rate, respectively). Analog signals corresponding to the volume flow rate), the fluid density (specific gravity) F1, the fluid temperature t, and the fluid pressures P0 and P1 are input. The output of the AD conversion circuit 13 inputs a digital signal corresponding to each analog signal to the data table 12 as a memory. The data table 12 includes a plurality of data corresponding to each of the digital signals, and outputs data stored at an address corresponding to each of the digital signals to the arithmetic circuit 10.

The data table 11 receives signals S0 to S4 output from an external input device (not shown). S0 is a signal corresponding to the shape of the static mixer (diameter, pipe length, number of elements, etc.), S1 is a signal corresponding to the specific gravity of the fluid when the specific gravity of the fluid is known, and S2 is a signal corresponding to the temperature of the fluid when the temperature of the fluid is known. Signal. In S3 and S4,
Signals relating to information on the outside air temperature, special fluid such as compressible fluid, or fluid pressure when the pressure upstream of the static mixer is kept constant can be applied. The data table 11 stores various data corresponding to the digital signals, and the data is stored in the arithmetic circuit 10.
Is output as a digital signal. For example, as data corresponding to the special fluid information, a change in viscosity due to the behavior of the special fluid is experimentally measured in advance and tabulated.

The arithmetic circuit 10 calculates the viscosity from the input data group. And a display device 14 comprising an LCD.
A signal corresponding to the viscosity is output, and the viscosity is displayed on the display device 14 in real time.

The arithmetic circuit 10, the data table 11, the data table 12, and the AD conversion circuit 13 are constituent elements of a means for determining the viscosity. The arithmetic circuit 10 calculates the viscosity based on at least the fluid pressures P0 and P1. Is programmed with a viscosity calculation formula (for example, Fanning's formula). Briefly, the static mixer 5
The shape of “a” is known, and the pressure loss, specific gravity, flow rate, and flow velocity can be measured.
The friction coefficient of a is determined, the Reynolds number is uniquely determined from the friction coefficient, and the viscosity can be determined from the Reynolds equation.

Next, the calculation of the viscosity in the means for calculating the viscosity shown in FIG. 2 will be described with reference to the flow chart shown in FIG. 3 which explains the calculation method of the viscosity measurement.

Referring to FIG. 3, in step 101, known data such as the static mixer shape (diameter, pipe length, number of elements, etc.), outside air temperature, etc., is input from a data input device (not shown). When the flow rate is controlled to be constant, a constant flow rate value is input in this step regardless of the measured value of the flow meter 1, and a specific gravity value is input when the specific gravity is constant.

In step 102, each of the input data is replaced with a data table value corresponding to the input data so as to facilitate the calculation.

In step 103, referring to the table data values and FIG. 2, the fluid pressure signals P0 and P1
Using the data table value corresponding to the converted digital signal, the viscosity is calculated from the Fanning viscosity calculation formula (see Equation 1), the relationship between the friction coefficient of the static mixer and the Reynolds number, and the Reynolds formula.

In step 104, an analog current corresponding to the specific gravity F1, the volume flow F0, the mass flow, the fluid, the flow velocity, and the fluid temperature t measured by the flow meter 1 and the thermometer 2 with reference to FIG. The digital value is converted into a digital value corresponding to the address of the data table, and this digital value is output as table data. The table data is a temperature correction value, a specific gravity correction value, and a flow rate correction value stored at an address corresponding to the digital value. And outputs table data corresponding to the shear rate correction value to the calibration unit in real time. For example, those whose specific gravity changes depending on the temperature are given in advance to the data table their behaviors obtained experimentally or theoretically. The same applies to specific gravity and flow rate. If the specific gravity, the flow rate, and the like do not change from the representative value, the representative value is input in step 101, and the deviation from the representative value such as the specific gravity, the flow rate, and the like can be used as correction data in step 104. The calibration section performs calibration of the viscosity according to each of the table data. These calibration data may be fed back to step 103.

When the specific gravity F1 and the mass flow rate (volume flow rate) F0 change, the data corresponding to, for example, F1 and F0 is substituted into the fanning equation together with the data corresponding to the fluid pressure signals P0 and P1 in step 103. Good.

If the accuracy of the required viscosity value can be relatively low, step 104 can be omitted.

In step 105, the calculated viscosity data (viscosity signal) is digitally output.

In step 106, the previous viscosity data is
/ A (digital / analog) conversion and analog output to the monitor as a continuous curve with time and viscosity as components.

The method of calculating the viscosity will be described in more detail. Equation (1) is a Fanning equation for calculating pressure loss when an isothermal incompressible fluid flows through a straight pipe. First, the Fanning's equation is modified to determine the friction coefficient of the static mixer.

[0066]

(Equation 1)

In the case of a static mixer having the same length and the same diameter as the straight pipe, it is obtained by correcting equation (1) as in equation (2).
However, ΔP = P0 (flow meter 3a) -P1 (flow meter 3b).

[0068]

(Equation 2)

When 1 / D = 1.5E, the equation (2) becomes
Referring to equation (1), equation (3) is obtained.

[0070]

(Equation 3)

Since the pressure loss ΔP of the static mixer is measured, the density ρ of the fluid, the average flow velocity u (determined from the flow rate) of the fluid are known or measured, and E (the number of elements of the static mixer) is known. From equation (3), f
_SM (Friction coefficient of static mixer) is required.

Subsequently, the viscosity is determined from the relationship between f _SM (the coefficient of friction of the static mixer) and the Reynolds number Re. The Reynolds number Re of the fluid flowing through the static mixer is
Within a certain Reynolds number range (eg, laminar flow, turbulent flow), it is uniquely determined by f _SM (the friction coefficient of the static mixer 5a). Therefore, in advance (or by calculation) experimentally f _SM (coefficient of friction static mixer) - Creates a Reynolds number Re diagram, by tabulating the data, f _SM (coefficient of friction static mixer)
Is used to determine the Reynolds number Re.

FIGS. 4A and 4B are diagrams showing the relationship between the friction coefficient f _CSM of the static mixer and the Reynolds number Re for explaining the method of calculating the viscosity according to one embodiment of the present invention. (A) is a diagram in a laminar flow region, and (B) is a diagram in a turbulent flow region. By tabulating the data of such a diagram, f _SM (static mixer 5
a), the Reynolds number Re can be easily obtained.

Next, the Reynolds equation is shown.

[0075]

(Equation 4)

Since the Reynolds number Re is obtained from f _SM (the coefficient of friction of the static mixer), the viscosity is calculated from this Reynolds equation.

The above is the case of a CSM (made of ceramics) type static mixer. If the friction coefficient of a static mixer such as a metal other than the CSM type is f _NSM , then f
_NSM = _fK (f is a coefficient of friction of a straight pipe corresponding to a static mixer, K is a pressure loss coefficient). K is an eigenvalue of the static mixer, and its value changes depending on the Reynolds number, and can be obtained experimentally in advance. Therefore, when a static mixer other than the CSM type is used, the viscosity can be calculated in the same manner as the CSM type static mixer in consideration of K (pressure loss coefficient).

FIG. 5 is a diagram showing the relationship between the strain (shear) rate and the viscosity. Referring to FIG. 5, in the case of a non-Newtonian fluid, the apparent viscosity changes depending on the shear speed D in the pipe. Therefore, it is preferable to perform correction based on the shear speed and use the viscosity at an infinite shear speed as an index. By tabulating the data of such a diagram, it becomes easy to correct the shear rate (shear rate) when measuring the viscosity of the non-Newtonian fluid. For example, the flow rate in the static mixer can be determined from the measured flow rate, and the shear rate at that time in the static mixer can be determined. Therefore, the viscosity serving as an index can be determined by changing the flow rate.

In the measurement of the viscosity of a non-Newtonian fluid, the viscosity serving as an index can be obtained by using various non-Newtonian viscosity models (for example, an exponential model).

Since the inside of the static mixer can be regarded as a piston flow, D = 8u '/ d0 (D shear speed, u' is the average flow velocity, and d0 is the pipe diameter). Therefore, since the average flow velocity u ′ is a function of the shear velocity D, the value substituted in the Reynolds equation changes. Therefore, the change of the apparent viscosity with respect to the displacement speed of the fluid is experimentally measured, the correlation coefficient between the displacement speed and the apparent viscosity is obtained, and the displacement is corrected for the viscosity (shear speed correction).

The change in the viscosity with respect to the temperature is corrected, for example, by obtaining the relationship between the temperature and the viscosity from the Andrade equation and creating a table. Further, in the apparatus of the present embodiment, the viscosity is measured while changing the temperature, and a temperature-viscosity diagram is prepared in advance and tabulated to obtain the index viscosity at the temperature serving as the index.

As for the flow rate correction and the specific gravity correction, correction values can be experimentally obtained and tabulated.

Although the method of calculating the viscosity of the in-line type viscosity device has been described above, the same applies to the case of the online type.

The viscosity measuring apparatus of this embodiment generates a pressure loss by passing the fluid through the static mixer 5a, and determines the viscosity of the fluid from the pressure loss ΔP (= P0−P1). Since the static mixer 5a has no movable parts inside and outside, it has high rigidity and can have a simple configuration as a whole. There is no dead space in the static mixer 5a, and fluid is mixed in the static mixer 5a. Therefore, it has high sanitary properties (cleanability). Therefore, it is particularly suitable for measuring high-density fluids with high fluid pressures or high-viscosity fluids that are likely to adhere and remain in the apparatus.

Further, in the viscosity measuring apparatus of this embodiment, the diameter of the static mixer on the side of the viscosity measuring apparatus can be appropriately selected according to the pipe diameter of the plant to be measured. Since the above device is not required, it is easy to insert inline or connect in parallel to piping of another plant or system to perform in-line measurement or online measurement.

The viscosity measurement range of the viscosity measuring apparatus of this embodiment can be flexibly changed by changing the diameter of the static mixer, the number of elements, and the like.

Even in the case of measuring the viscosity of a non-Newtonian fluid, accurate measurement of the viscosity is possible because the viscosity measuring device itself has very little influence on the viscosity of the fluid.

Further, since the viscosity measuring apparatus of this embodiment has high sanitary properties as described above, it is very hygienic to apply the viscosity measuring apparatus of this embodiment to a food production plant. Since the viscosity is measured more accurately and continuously, the state of the fluid can be grasped accurately and continuously from the viscosity of the fluid.

For example, when the fluid to be measured is a fermented food, the progress of fermentation can be recognized from the viscosity, so that it is not necessary to take out (sample) the food to the outside. For this reason, there is no disturbance to the internal fluid due to the sampling, which is sanitary.

In addition, by using the viscosity measuring apparatus of the present embodiment, it is possible to constitute a feedback system for controlling the supply of the raw material of the fluid whose viscosity is to be measured in accordance with the measured viscosity. Examples of the supply control device include a transfer pump that controls the supply of a fluid or the like, a feeder that controls the supply of a solid (powder) or the like, a valve that controls the supply of a gas or the like, and the like.

The viscosity measuring apparatus of this embodiment can be used for measuring the viscosity of any fluid (for example, one containing air bubbles, a fluid solid, etc.). It can be used in all fields such as the food industry, water treatment industry, and pulp and paper industry. In particular, it is suitable for measuring the viscosity of a fluid having a tendency to become a non-Newtonian fluid, such as an adhesive, a sticky material, or a resin.

<Embodiment 2> Next, as another embodiment, FIG.
Shows an in-line type viscosity measuring device.

Referring to FIG. 6, the viscosity measuring device has the same configuration as the in-line type viscosity measuring device of the first embodiment of the present invention except that it has two flow meters 1a and 1b. The description is omitted. The electromagnetic flow meter 1a measures a volume flow rate (l / H) of a fluid introduced into the static mixer. Since the tube volume is known, the flow rate of the fluid in the flow velocity (static mixer) is determined from this flow rate. 1
a may be a capacity type flow meter, and both are suitably used when the specific gravity is known. The mass flow meter 1b measures a mass flow rate (Kg / H) and a specific gravity value (density) (g / cm ³ ) of the fluid introduced into the static mixer. When the behavior of the specific gravity is unknown, the specific gravity value is obtained in real time, which is effective.
Note that mass flow rate / specific gravity value = volume flow rate.

<Embodiment 3> Further, as another embodiment, an in-line type viscosity measuring apparatus provided with another static mixer 5c upstream of the viscosity measuring apparatus shown in FIG. 6 is shown in FIG.
Shown in

Referring to FIG. 7, in the in-line type viscosity measuring device, the static mixer 5c agitates and homogenizes the fluid before it is introduced into the static mixer 5a for viscosity measurement, so that a more accurate viscosity can be obtained. You can make measurements.

As described above, the present invention has been described with reference to the above embodiments. However, the present invention is not limited to the above embodiments, but includes various embodiments in accordance with the principle of the present invention.

[0097]

As described above, the viscosity measuring apparatus and the measuring method of the present invention realize the viscosity measurement by a completely new principle of using a static mixer, that is, by a simple structure, and are notable in themselves. Make technological progress. In addition, expanding the use of static mixers,
The realization of its unknown potential has a significant effect. Further, according to the viscosity measuring device and the measuring method using the static mixer of the present invention, the static mixer has no movable portion inside and outside, so that the rigidity is high and the whole device can have a simple configuration. Since there is no dead space in the mixer and the fluid is mixed in the static mixer, the sanitary property (cleaning property) is high. Therefore, it is particularly suitable for measuring high-density fluids with high fluid pressures or high-viscosity fluids that are likely to adhere and remain in the apparatus. Furthermore, the viscosity measuring device of the present invention can appropriately select the static mixer diameter on the viscosity measuring device side according to the piping diameter of the plant to be measured, and requires a complicated and large-sized device such as an external power source. Therefore, it is easy to perform in-line measurement or online measurement by inserting in series or connecting in parallel to piping of another plant or system. The viscosity measurement range can be flexibly changed by changing the aperture of the static mixer, the number of elements, and the like, so that measurement can be actually performed over a wide range. Further, even in the case of measuring the viscosity of a non-Newtonian fluid, accurate measurement of the viscosity is possible because the viscosity measuring device itself has very little influence on the viscosity of the fluid (claims 1 and 5).

Further, by connecting the static mixer in-line with the pipe through which the fluid whose viscosity is to be measured flows, the viscosity measuring apparatus of the present invention can be made compact and cost can be reduced (claim 2).

By connecting the static mixer on-line to the pipe through which the fluid whose viscosity is to be measured flows, the viscosity measuring apparatus of the present invention can be easily applied to existing systems and plants (claim 3).

The means for obtaining the viscosity measures the temperature, the flow rate and the density in real time by using the outputs of the temperature measuring means, the flow rate measuring means and the density measuring means as inputs, thereby obtaining a more accurate viscosity. In the case of measuring the viscosity of a non-Newtonian fluid, a change in viscosity according to the shear rate can be measured (claim 4).

Further, the flow rate and density of the fluid are measured in real time, the viscosity of the fluid is determined at least using Fanning's equation, the temperature and shear rate are measured, the specific gravity or viscosity is corrected by temperature, and the non-Newtonian fluid is corrected. In the case of (1), by performing the shear rate correction, an accurate and index viscosity can be obtained (claim 6).

[Brief description of the drawings]

FIG. 1 is a piping diagram illustrating a configuration of an in-line and on-line viscosity measuring device according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of an in-line viscosity measuring device according to one embodiment of the present invention.

FIG. 3 is a flowchart for explaining a calculation method for calculating a viscosity of a viscosity in a means for calculating a viscosity, in particular, according to an embodiment of the present invention.

FIGS. 4A and 4B are diagrams according to one embodiment of the present invention;
It is a diagram showing the relationship between the friction coefficient f _CSM of the static mixer and the Reynolds number Re of the static mixer for explaining the calculation method of the viscosity measurement, (A) is a diagram in a laminar flow region, and (B) is a diagram in a turbulent flow region.

FIG. 5 is a diagram showing a relationship between a strain (shear) rate and a viscosity.

FIG. 6 is a piping diagram illustrating a configuration of an inline viscosity measurement device having two flow meters according to another embodiment of the present invention.

FIG. 7 is a piping diagram illustrating a configuration of an inline viscosity measurement device having another static mixer upstream according to still another embodiment of the present invention.

FIG. 8 is an explanatory view showing a conventional orifice type viscosity measuring method.

FIG. 9 is an explanatory view showing a conventional viscosity measurement method using a resistance plate (shear force measurement) method.

FIG. 10 is an explanatory view showing a conventional viscosity measurement method using a rotary cylinder.

FIG. 11 is a cross-sectional view showing a conventional orifice type viscosity measuring device using a metering pump provided with gears.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Flow meter 1a Electromagnetic flow meter (positive displacement flow meter) 1b Mass flow meter 2 Thermometer 3a, 3b, 3c, 3d Pressure gauge 4a, 4b Piping 5a, 5b, 5c Static mixer 6 Sampling pump 10 Operation circuit 11 Data table 12 Data table 13 A / D (analog / digital conversion circuit) 14 Display device F0 Flow rate (mass flow rate, volume flow rate) F1 Fluid density (specific gravity) t Fluid temperature P0, P1 Fluid pressure S0 Static mixer shape (bore diameter, pipe length and number of elements) Etc.) Signal S1 Fluid specific gravity signal S2 Fluid temperature signal S3 Outside air temperature signal S4 Special fluid information signal 100 Orifice 101 Resistance plate 102 Rotating cylinder

Claims (6)

(57) [Claims] A means for dividing a fixed flow into a flow path;
A static mixer that mixes fluids by changing streamlines, pressure gauges provided respectively on the upstream side and the downstream side of the static mixer, and a fluid flowing through the static mixer based on a pressure difference indicated by the pressure gauge And a means for determining the viscosity of the viscosity. 2. A viscosity measuring apparatus using a static mixer according to claim 1, wherein the static mixer is connected in-line to a pipe through which a fluid whose viscosity is to be measured flows. 3. A viscosity measuring apparatus using a static mixer according to claim 1, wherein said static mixer is connected online to a pipe through which a fluid whose viscosity is to be measured flows. 4. A flow of a fluid whose viscosity is to be measured is flown by a temperature measuring means for measuring a temperature of the fluid, a flow measuring means for measuring a flow rate of the fluid, and a density measuring means for measuring a density of the fluid. The static mixer according to claim 1, wherein the static mixer is provided in a pipe, and the means for determining the viscosity receives an output of the temperature measuring means, the flow rate measuring means, and the density measuring means as an input. Viscosity measuring device. 5. A device for dividing a fixed flow into a flow path,
Flowing the fluid to a static mixer that mixes the fluid by changing a streamline, measuring a pressure loss value of the fluid by the static mixer, and determining a viscosity of the fluid based on the pressure loss value. Viscosity measurement method using a static mixer. 6. A method of measuring the flow rate, density, temperature, and shear rate of the fluid, and obtaining the viscosity of the fluid by Fanning's formula based on the flow rate, density, temperature, and shear rate of the fluid. A viscosity measurement method using a static mixer.