JP6989903B2 - Mixing performance measurement method - Google Patents

Description

Patent Law Article 30 Paragraph 2 Applicable Meeting Name Chemical Engineering Society Chugoku-Shikoku Branch / Kansai Branch Joint Branch Meeting Graduate Student Presentation Date December 12, 2015 Website Address http: // www3. scej. org / meeting / 81a / program / room_D2. html website publication date February 28, 2016 Meeting name Chemical Engineering Society 81st year meeting Date March 14, 2016

The present invention relates to a mixing performance measuring method.

There is a static mixer disclosed in Patent Document 1 as a static mixing device that mixes a fluid inside a pipe without a moving part. This is a baffle plate twisted at a predetermined angle about a tube axis, and a plurality of mixing elements are arranged in a tubular housing along the axial direction. In the static mixing device, the fluid is divided, converted, and inverted by the mixing element in the process of moving in the tubular housing and mixed.

Special Fair 1-31928 Gazette

However, in the static mixing device disclosed in Patent Document 1, as shown in FIGS. 5 and 6 of Patent Document 1, the mixing element into which the fluid flows passes through the center of the pipe axis in the cross-sectional view of the pipe. Since it exists only as one straight line that divides the cross section into two, the fluid is only divided into two in a plane. In this case, for example, in the mixing of two fluids, when the flow rate ratio of the fluids is large and the flow rate of one fluid is small and the flow rate is small, as one straight line that passes through the center of the pipe axis and divides the pipe cross section into two in the view of the pipe cross section. There is a problem that a small flow rate fluid must be divided by an existing mixing element, and it is difficult to mix the fluid. This means that in a fluid containing two or more components, when the concentration difference of each component is large and each component is unevenly distributed in the fluid, the components are mixed so as to be uniformly distributed in the fluid. The same is true when doing so.

Therefore, it is desired to provide a mixing technology capable of reliably mixing even if the difference in the flow rate of two or more fluids or the difference in the concentration of the components in the fluid is large, and the mixing can be performed in a small space. Will be done. Further, it is desired to provide a measuring method of mixing performance which should be a judgment index of a mixed state.

The present invention has been made in view of the above, and an object of the present invention is to provide a mixing performance measuring method that should be a judgment index of a mixed state of two or more fluids.

The mixing performance measuring method according to the present invention is
A high-viscosity aqueous solution colored with a fluorescent colorant is injected into a water stream flowing through a pipe installed upstream of the mixing device, mixed by the mixing device, and is transparent downstream of the mixing device and having the same inner diameter as the piping on the upstream side. A pipe is installed, a fluid mixed by the mixing device is allowed to flow in the transparent pipe, a laser sheet light is irradiated from the pipe radial direction of the transparent pipe, a pipe cross-sectional image of the transparent pipe is taken by a camera, and the pipe is taken. The cross-sectional image is processed as a circular image by an image processing program to obtain the brightness of the pixels, and the brightness of the pixels having a predetermined threshold value or more is used as a judgment index of the mixed state of the fluid.

In the mixing performance measurement method,
The average value of the brightness of the top 50% of the pixels from the high brightness side of all the pixels of the circular image can be used as a judgment index of the mixing state of the fluid with the mixing degree bm.

In the mixing performance measuring method,
Of all the pixels of the circular image, the pixels whose brightness is equal to or higher than the predetermined threshold value are defined as fluorescent pixels.
The dispersion degree M is obtained by expressing the number of pixels of the fluorescent pixels as a percentage of the total number of pixels of the circular image, and the dispersion degree M can be used as an index showing the spread of the fluid due to mixing.

In the mixing performance measuring method,
Of all the pixels of the circular image, the pixels whose brightness is equal to or higher than the predetermined threshold value are defined as fluorescent pixels.
The median value of the brightness of the fluorescent pixel can be set as the median concentration bmed, and the median concentration bmed can be used as an index representing the representative concentration of the fluid by mixing.

In the mixing performance measuring method,
We define n'(b) = n (b) ^{b / 255} , which is exponentially weighted to the number of pixels n (b) at each luminance (b = 0 to 255) of all the pixels of the circular image. The brightness at which this n'(b) is maximized can be defined as the maximum density b'max, and the maximum density b'max can be used as an index indicating the existence of a thick mass.

In the mixing performance measuring method,
Of all the pixels of the circular image, the pixels whose brightness is equal to or higher than the predetermined threshold value are defined as fluorescent pixels.
Based on n'(b) = n (b) ^{b / 255} , which is exponentially weighted with respect to the number of pixels n (b) at each brightness (b = 0 to 255) of all the pixels of the circular image. The median value of this n'(b) is defined as the median concentration bmed, and the number of fluorescent pixels is expressed as a percentage of the total number of pixels of the circular image for each thick mass extracted with the median concentration bmed + 30 as a threshold value. The size of the thick mass can be L.

In the mixing performance measuring method,
Of all the pixels of the circular image, the pixels whose brightness is equal to or higher than the predetermined threshold value are defined as fluorescent pixels.
When other fluids with different specific densities are mixed with mainstream water, the eccentricity Dev. It can be obtained in this way.

Position information p of -1 to 1 is given to each pixel of the circular image from the lower part to the upper part, and p'= p · b / bmax weighted by the luminance is obtained for each position information p (here, bmax). Is the maximum value of the luminance b in each image .).
The maximum value p'max and the minimum value p'min are obtained for the p'of each pixel, and the center of p'for the pixel with the maximum value p'max ± 0.5 and the pixel with the minimum value p'min ± 0.5. Calculate the values and set them as p'max _± 0.5 and _{p'min ± 0.5} , respectively.
2.5% of the number of fluorescent pixels is n _2.5 , the number of pixels of p'max ± 0.5 is n _{max ± 0.5} , and the number of pixels of p'min ± 0.5 is n _{min ± 0.5} . On the other hand, p'max, c corrected using n _2.5 and p'min, c corrected using n _2.5 with respect to p'min were obtained for each case as follows, and p'max, Let the sum of c and p'min, c be the uneven distribution degree Dev. Indicated by a value from -1 to 1.

INDUSTRIAL APPLICABILITY According to the present invention, a method for measuring mixing performance that should be a judgment index for a mixing state of two or more fluids is provided.

It is an exploded perspective view which shows the mixing unit used for the fluid mixing method of Embodiment 1. FIG. FIG. 5 is a plan view of a mixing element forming a mixing unit used in the fluid mixing method of Form 1. FIG. 2 (c) is a plan view of the mixed elements of FIGS. 2 (a) and 2 (b) in a laminated state. It is sectional drawing which shows the flow state of the fluid in the mixing unit used in the mixing method of the fluid of mode 1. FIG. FIG. 3A shows a flow state in the stacking direction, and FIG. 3B shows a flow state in the radial direction. It is an exploded perspective view which shows the mixing unit used in the modification 1 in the fluid mixing method of Embodiment 1. FIG. It is a top view of the state in which the mixing element forming the mixing unit used in the modification 1 in the method of mixing the fluid of the first embodiment is laminated. It is a top view of the mixing element used in the modification 2 in the fluid mixing method of Embodiment 1. FIG. FIG. 6 (c) is a plan view of the mixed elements of FIGS. 6 (a) and 6 (b) in a laminated state. It is a top view of the mixing element used in the modification 3 in the fluid mixing method of Embodiment 1. FIG. 7 (c) is a plan view in a state where the mixed elements of FIGS. 7 (a) and 7 (b) are laminated. It is a top view of the mixing element used in the modification 4 in the fluid mixing method of Embodiment 1. FIG. FIG. 8 (c) is a plan view of the mixed elements of FIGS. 8 (a) and 8 (b) in a laminated state. It is a perspective view of the mixing element used in the modification 5 in the fluid mixing method of Embodiment 1. FIG. It is sectional drawing which shows the flow state in the stacking direction in the state which the mixing element used in the modification 5 in the fluid mixing method of Embodiment 1 is laminated. It is a perspective view which showed the example of the case where the mixing element in the fluid mixing method of the first form has a divided structure. It is sectional drawing which shows the flow state of the fluid in the static mixing apparatus used in the mixing method of the fluid of Embodiment 2. It is sectional drawing which shows the flow state of the fluid in the static mixing apparatus used in the modification 1 in the fluid mixing method of the 2nd embodiment. It is sectional drawing which shows the flow state of the fluid in the static mixing apparatus used in the modification 2 in the method of mixing the fluid of the 2nd embodiment. FIG. 15A is a schematic flow chart of the measuring device in a mixed state, and FIG. 15B is a histogram showing the mixing degree bm and a corresponding cross-sectional image of the pipe. It is a top view of the mixing element used for the measurement of a mixed state. 16 (c) is a plan view of the mixed elements of FIGS. 16 (a) and 16 (b) in a laminated state.

(Form 1 "Fluid mixing method using a mixing unit")
As shown in FIGS. 1 and 2, the mixing unit 1A used in the fluid mixing method according to the present invention is provided with a first through hole 22 and a second through hole 23 constituting the mixture 2A. The elements 21a and 21b are provided with a disk-shaped first plate 3 and a second plate 4 provided at both ends of the mixing elements 21a and 21b in the stacking direction. The first plate 3 and the second plate 4 are brought into close contact with both end faces of the mixing elements 21a and 21b in the stacking direction by, for example, fixing means of four bolts 11 and nuts 12 arranged at appropriate positions. It is attached. Therefore, when the fixing means is removed, the mixing elements 21a and 21b are disassembled into the first plate 3 and the second plate 4.

The first plate 3 is formed of a disk having a bolt hole 13. The second plate 4 is formed of a disk having a circular opening 41 in which the fluid A flows in or out in the central portion together with the bolt hole 14. The first plate 3 and the second plate 4 have substantially the same outer diameter as the mixing elements 21a and 21b constituting the mixture 2A.

As shown in FIG. 2, a plurality of substantially quadrangular first through holes 22 are formed in the mixing elements 21a (FIG. 2A) and 21b (FIG. 2B), and the first through hole 22 is formed in the central portion. A substantially circular second through hole 23 having an inner diameter larger than that of the through hole 22 is formed. The second through hole 23 is arranged substantially the same as and substantially concentrically with the inner diameter of the opening 41 of the second plate 4. The second through hole 23 communicates between the mixing elements 21a and 21b in the stacking direction, and forms the hollow portion 24 of the mixture 2A. The plurality of first through holes 22 are arranged concentrically around the center point of the second through holes 23, and are arranged in a staggered manner as a whole. In one of the mixing elements 21a, the first through hole 22 arranged in the inner peripheral portion is closed, and the first through hole 22 arranged in the outer peripheral portion is opened toward the outer peripheral surface. In the other mixing element 21b, the first through hole 22 arranged in the inner peripheral portion is opened toward the inner peripheral surface, and the first through hole 22 arranged in the outer peripheral portion is closed.

As shown in FIGS. 2C and 3, since the mixing elements 21a and 21b have different arrangement patterns of the first through holes 22, each first through hole 22 is formed in the stacking direction. The mixing elements 21a and 21b are arranged so as to be partially displaced and overlap each other in the radial direction and the circumferential direction with respect to the first through hole 22 of the adjacent mixing elements 21a and 21b, and the mixing elements 21a and 21b are arranged in the extending direction (relative to the stacking direction). (Approximately vertical direction).

In the mixing unit 1A, the first plate 3 and the second plate 4 are arranged to face each other at both ends of the mixture 2A, so that the fluid A flowing into the inside of the mixture 2A is the mixing element 21a at both ends in the stacking direction. , 21b is prevented from flowing out from the first through hole 22. Therefore, as shown in FIGS. 3A and 3B, the fluid A reliably circulates inside the mixture 2A in the extending direction as well as in the stacking direction of the mixing elements 21a and 21b. Then, the fluid A is circulated inside the mixing unit 1A from the inner peripheral portion to the outer peripheral portion.

When, for example, the fluid A is flowed into the hollow portion 24 through the opening 41 of the second plate 4 by an appropriate pumping means into the above mixing unit 1A, the fluid A opens on the inner peripheral surface of the hollow portion 24. It flows into the inside of the mixture 2A from the first through hole 22 of the mixing element 21b. Subsequently, the fluid A passes through the other first through hole 22 communicating with the first through hole 22 and through the other first through hole 22 communicating with the other first through hole 22. Repeat the flow. Finally, the fluid A flows out of the mixture 2A through the first through hole 22 of the mixing element 21a that opens on the outer peripheral surface of the mixture 2A.

During this time, the fluid A inside the mixture 2A is divided and merged in the extending direction of the mixing elements 21a and 21b by the plurality of first through holes 22, and flows substantially radially from the inner peripheral portion to the outer peripheral portion. (See FIG. 3 (b)) At the same time, the mixing elements 21a and 21b are also divided and merged in the stacking direction (see FIG. 3 (a)).

As described above, the fluid A is divided and merged not only in the two-dimensional (planar) direction in the radial direction but also in the layer thickness direction of the mixing elements 21a and 21b inside the mixture 2A. A three-dimensional division and merging with a spread is performed inside the mixture 2A. Therefore, according to this mixing unit 1A, a high mixing effect is exhibited with respect to the fluid A.

Since the first through holes 22 of the mixing elements 21a and 21b constituting the mixture 2A are arranged in a staggered manner, between the first through holes 22 and the other upper and lower first through holes 22. When the fluid A flows out and flows in, the flow of the fluid A is easily divided and merged, so that the fluid A is efficiently mixed. Therefore, even when the flow rate of the fluid A is small, the fluid A is divided and merged and mixed well.

Since the second through hole 23 has an inner diameter larger than that of the first through hole 22, the flow resistance when flowing through the hollow portion 24 formed by the second through hole 23 of each of the mixing elements 21a and 21b is mixed. It is small compared to the flow resistance when flowing inside the body 2A. Therefore, even when the number of stacked elements 21a and 21b is large, the fluid A reaches the inner peripheral portions of the mixed elements 21a and 21b substantially evenly regardless of the position in the stacking direction, and the inside of the mixture 2A is inside. It flows almost evenly from the peripheral part to the outer peripheral part. By providing such a hollow portion 24, it becomes easier for the fluid A to enter substantially evenly in the stacking direction inside the mixing unit 1 as compared with the case where the hollow portion 24 is not provided.

Since the mixing unit 1A is composed of the mixing elements 21a and 21b, the first plate 3 and the second plate 4, the flow path area through which the fluid flows is increased by increasing the number of laminated mixing elements 21a and 21b. So many fluids can be mixed.

(Modification 1)
FIG. 4 is an exploded perspective view showing the components of the mixing unit 1B according to the first modification of the first embodiment. FIG. 5 is a plan view showing the overlap of the first through holes 22 when the mixing element 21c is laminated with the adjacent mixing element 21c. The portion where the first through hole 22 overlaps is shown in color.

Similar to the mixing unit 1A shown in FIG. 1, the mixing unit 1B is a mixture 2B in which a plurality of (here, 6) mixing elements 21c composed of disks are laminated, and the first plate 3 and the second plate 3 and the second. It is configured by being sandwiched from both sides by a fixing means of four bolts 11 and nuts 12 arranged at appropriate positions by a plate 4.

The mixing element 21c has a plurality of circular first through holes 22 and a substantially circular second through hole 23 in the central portion. The inner diameter of the second through hole 23 is substantially the same as and substantially concentric with the inner diameter of the through hole 41 of the second plate 4. By stacking the mixing elements 21c, the second through hole 23 forms the hollow portion 24. Each of the first through holes 22 has substantially the same inner diameter and pitch.

As shown in FIG. 5, a part of the plurality of first through holes 22 is arranged so as to partially overlap with the first through holes 22 of the mixing element 21c adjacent to each other so as to be partially overlapped with each other. Communicate in the extending direction of the element 21c. A part of the plurality of first through holes 22 is open on the inner peripheral surface and the outer peripheral surface of the mixing element 21c.

Even with the mixing unit 1B as described above, the plurality of first through holes 22 are formed so as to communicate with each other in the extending direction and the stacking direction of the mixing element 21c. Therefore, the fluid A is circulated inside the mixing unit 1B from the inner peripheral portion to the outer peripheral portion, or vice versa, and is three-dimensionally divided and merged in the radial direction and the stacking direction. , Fluid A is well mixed.

(Modification 2)
In the mixing elements 21a or 21b shown in FIGS. 1 to 3, one of the first through holes 22 arranged in the inner portion or the outer portion is open toward the inner surface or the outer surface, which is shown in FIG. As described above, the mixing elements 21d (FIG. 6 (a)) and 21e (FIG. 6 (b)) having the first through holes 22 arranged in the inner portion and the outer portion are closed but have different inner and outer diameters. Can also be used to form the mixing unit 1.

The outer diameter and inner diameter of the mixing element 21d shown in FIG. 6 (a) are smaller than the outer diameter and inner diameter of the adjacent mixing element 21e shown in FIG. 6 (b). Like the mixing elements 21a and 21b, the second through hole 23 is arranged in a substantially circular shape at a substantially central portion. As a result, the first through hole 22 of the mixing element 21d is opened in the inner peripheral portion of the mixture 2, and the first through hole 22 of the element 21e is opened in the inner peripheral portion of the inside of the mixture 2 (FIG. 6). (C)). In FIG. 6C, the mixing element 21e is colored to make it easier to understand the laminated state.

Even if the mixing elements 21d and 21e are formed as described above, the plurality of first through holes 22 are formed so as to communicate with each other in the extending direction and the stacking direction of the mixing elements 21d and 21e. Therefore, the fluid A flows into the inside of the mixture 2 from the first through hole 22 of the mixing element 21d opened to the inner peripheral portion of the mixture 2, and the plurality of first through holes communicating with the inside of the mixture 2. 22 flows from the inner peripheral portion to the outer peripheral portion, and flows out of the mixture 2 through the first through hole 22 of the mixing element 21e opened to the outer peripheral portion of the mixture 2. Then, when the fluid A flows through the inside of the mixture 2, it is three-dimensionally divided and merged in the radial direction and the stacking direction, and is mixed well.

Further, the mixing element 21 in which the first through holes 22 arranged in the inner and outer portions are closed, such as the mixing element 21d or 21e, and the first through holes arranged in the inner and outer portions. By combining the mixing elements 21 in which the 22 is open, the radial partition wall 25a and the circumferential partition wall 25b of each mixing element 21 are arranged at different positions to provide the fluid A in the same manner as described above. It may flow into the mixture 2 and flow out.

(Modification 3)
As shown in FIG. 7, in the laminated state (FIG. 7 (c)) of the two types of mixed elements 21f (FIG. 7 (a)) and 21 g (FIG. 7 (b)), the first one adjacent to each other in the circumferential direction. The partition wall 25a in the radial direction may be arranged so that the areas of the overlapping portions of the through holes 22 are non-uniform. As a result, the fluid is divided non-uniformly with respect to the circumferential direction as it passes through the first through hole 22.

(Modification example 4)
As shown in FIG. 8, among the partition walls between the first through holes 22 in the two types of mixing elements 21h (FIG. 8 (a)) and 21i (FIG. 8 (b)), the partition wall in the radial direction. 25a may be formed into a substantially involute curve that curves in one direction. By forming the mixing elements 21h and 21i in this way, the flow of the fluid A flowing out of the mixing unit 1 can be made into a spiral flow.

(Modification 5)
The mixing element 21j as shown in FIG. 9 may be used to form the mixing unit 1C shown in FIG. The mixing element 21j has a rectangular first through hole 22 on the entire surface without providing a second through hole 23 in the central portion, and the frame portion 26 in which the first through hole 22 is not opened in the outer peripheral portion. have. The outer peripheral shape of the first plate 3 is formed to have a smaller diameter than the mixing element 21j so that the first through hole 22 in the outer peripheral portion of the adjacent mixing element 21j is opened.

FIG. 10 is a cross-sectional view showing how the fluid A flows inside the mixing unit 1C in which three mixing elements 21j are laminated. Even if the mixing unit 1C is configured in this way, the fluid A that has flowed into the mixing unit 1C by an appropriate pumping means flows into the mixture 2C through the through hole 41 of the second plate 4 and is mixed. While flowing through the first through hole 22 through which the element 21j communicates, the inside of the mixture 2C is three-dimensionally divided and merged in the radial direction and the stacking direction to be mixed well. Then, the fluid A flows out from the first through hole 22 opened in the outer peripheral portion of the first plate 3 disposed at one end of the mixture 2C.

Further, the mixing element 21 according to the present invention is not limited to the above-mentioned form and each modification, and various modifications can be made. For example, the first through hole 22 of the mixing element 21 is not limited to a circular shape or a rectangular shape, but may be a polygonal shape such as a triangle, a hexagon, or a rectangle.

Further, the mixture 2 may be composed of an integral body having a hierarchical structure in which the mixing element layer 21 is formed in the layer thickness direction. In this case, the mixture 2 can be manufactured by, for example, a three-dimensional modeling device such as a 3D printer. Further, the mixing unit 1 can also be manufactured by a three-dimensional modeling device such as a 3D printer in the same manner as the mixing unit 2.

Further, the mixing element 21, the first plate 3, the second plate 4, and the like can be divided into various shapes. In this case, even a large mixing unit 1 can be easily manufactured. As shown in FIG. 11, when the mixing element 21 has an annular shape, it can be divided by a fan-shaped divided body 27. Further, when the mixing element 21 is a quadrangle, it can be divided into a rectangular-shaped divided body.

Further, the fluid A is the first through hole 2 of the mixing element 21 opened to the outer peripheral portion of the mixture 2.
It may flow into the inside of the mixture 2 from 2 and flow out from the first through hole 22 of the mixing element 21 opened to the inner peripheral portion of the mixture 2. In the case of the fifth form shown in FIG. 10, the fluid A flows in from the first through hole 22 opened to the outer peripheral portion of the first plate 3 disposed at one end of the mixture 2C. It may flow out from the opening 41 of the second plate 4.

(Form 2 "Fluid mixing method using a static mixing device")
FIG. 12 is a cross-sectional view showing how the fluid A flows inside the static mixing device in the fluid mixing method according to the second embodiment. In the static mixing device 5A, an outer peripheral disk-shaped flange 54 having an inlet 51 and an outlet 52 is detachably attached to a cylindrical casing 50 having a flange 53. A mixing unit 1 is arranged inside the casing 50.

The mixing unit 1 is formed of four mixture 2, and each mixture 2 has a plurality of mixing elements 21 (here, three) and a through hole 41 in the center, which is substantially the same as the inner diameter of the casing 50. It is composed of a second plate 4 having a diameter and a first plate 3 having an outer diameter substantially the same as the outer diameter of the mixture 2.

More specifically, on the inlet 51 side of the casing 50, a second plate 4 is disposed, followed by a first mixture 2a formed from the three mixing elements 21, followed by a first. Plate 3 is arranged. Subsequently, the second mixture 2b, the second plate 4, the third mixture 2c, the first plate 3, the fourth mixture 2d, and the second plate 4 are sequentially arranged. Adjacent first mixture 2a and second mixture 2b share one first plate 3 to form two mixing elements 1a and 1b. Similarly, the adjacent third mixture 2c and the fourth mixture 2d also share one first plate 3 to form two mixing elements 1c and 1d. Further, the adjacent second mixture 2b and the third mixture 2c share one second plate 4 to form two mixing elements 1b and 1c.

The mixing unit 1 is fixed in the casing 50 by an appropriate method using bolts, nuts, elastic bodies, or the like. The mixing unit 1 of the first plate 3, the second plate 4 and the mixture 2 is also fixed by appropriate fixing means such as bolts and nuts.

The mixing element 21 forming each of the mixtures 2a to 2d has a plurality of first through holes 22 like the mixing elements 21a and 21b, and has an inner diameter of the through hole 41 of the second plate 4 in the central portion. It has a circular second through hole 23 that is substantially identical and substantially concentric. By stacking the mixing elements 21, the second through hole 23 constitutes the first hollow portion 24a, the second hollow portion 24b, the third hollow portion 24c, and the fourth hollow portion 24d.

A first annular space portion 55a is provided between the inner peripheral portion of the casing 50 and the outer peripheral portions of the first mixture 2a and the second mixture 2b, and the outer periphery of the third mixture 2c and the fourth mixture 2d. A second annular space portion 55b is formed between the portions.

For example, the fluid A flows into the static mixing device 5A having the above configuration from the inlet 51 by an appropriate pumping means, and flows into the first hollow portion 24a. Subsequently, the fluid A flows into the inside of the first mixture 2a from the first through hole 22 opened on the inner peripheral surface of the first hollow portion 24a, and flows through the communicating first through hole 22 in the outer peripheral direction. Subsequently, the fluid A flows out from the first through hole 22 opened in the outer peripheral surface of the first mixture 2a and flows into the first annular space portion 55a.

Subsequently, the fluid A flows into the inside of the second mixture 2b from the first through hole 22 opened on the outer peripheral surface of the second mixture 2b, and flows through the communicating first through hole 22 in the inner peripheral direction. Then, the fluid A flows out from the first through hole 22 opened in the inner peripheral surface of the second hollow portion 24b, and flows into the second hollow portion 24b.

After that, the fluid A flows out from the outlet 52 via the third hollow portion 24c → the third mixture 2c → the second annular space portion 55b → the fourth mixture 2d → the fourth hollow portion 24d. As described above, the fluid A has a first through hole 22 that communicates the inside of the mixture 2 radially from the inner peripheral portion to the outer peripheral portion or from the outer peripheral portion to the inner peripheral portion inside each of the mixtures 2a to 2d. By circulating the above, the cells are three-dimensionally divided and merged in the radial direction and the stacking direction to be efficiently mixed. As described above, the fluid A flowing in from the inlet 51 of the static mixing device 5A is well mixed and flows out from the outlet 52.

According to the method of mixing a fluid using the static mixing device 5A, the fluid A is mixed by the first plate 3 and the second plate 4 which are arranged to face each other at both ends of the respective mixtures 2a to 2d. 2 The direction of flow inside can be changed from the inner peripheral portion to the outer peripheral portion or from the outer peripheral portion to the inner peripheral portion. Therefore, since the fluid A circulates through the first through hole 22 in which more communication is performed, the mixing degree of the fluid A can be further increased.

Further, since the hollow portions 24a to 24d and the annular space portions 55a and 55b have a sufficient size for the first through hole 22, the fluid A is the hollow portions 24a to 24d and the annular space portions 55a, respectively. The flow resistance when flowing through 55b is smaller than the flow resistance when flowing inside each of the mixtures 2a to 2d. Therefore, the fluid A reaches the inner peripheral portion or the outer peripheral portion of each mixing element 21 substantially evenly regardless of the position in the stacking direction even when the number of laminated mixing elements 21 is large, and the inside of each mixture 2a to 2d. Flows substantially evenly from the inner peripheral portion to the outer peripheral portion and vice versa from the outer peripheral portion to the inner peripheral portion.

(Modification 1)
FIG. 13 is a cross-sectional view showing how the fluid A flows inside the static mixing device 5B in the fluid mixing method according to the first modification of the second embodiment. Since the outer diameter of the mixing element 21 constituting each of the mixtures 2a to 2d is substantially the same as the inner diameter of the casing 50, the static mixing device 5B in the first modification is annular, unlike the static mixing device 5A of FIG. It does not have the space portions 55a and 55b, and the outer diameter of the first plate 3 is smaller than the outer diameter of the second plate 4 and the mixture 2. Therefore, the fluid A communicates between the first mixture 2a and the second mixture 2b, and between the third mixture 2c and the fourth mixture 2d, between the first through holes 22 communicating with each other at the outer peripheral portion. It is distributed in.

Even with such a configuration, the fluid A is mixed by flowing through the communicating first through hole 22 inside each of the mixtures 2a to 2d in the extending direction of the mixing element 21. In the present modification 1, since the outer diameter of the mixing element 21 and the outer diameter of the second plate 4 are substantially the same as the inner diameter of the casing 50, it is easy to install these casings 50 inside.

(Modification 2)
FIG. 14 is a cross-sectional view showing how the fluid A flows inside the static mixing device 5C in the fluid mixing method according to the second modification of the second embodiment. In the static mixing device 5C in the second modification, the static mixing device 21 of FIG. 13 is static except that the mixing element 21 constituting the first mixture 2a to the fourth mixture 2d does not have the second through hole 23. It is the same as the target mixing device 5B. For example, the mixing element 21j shown in FIG. 9 is applied to the second modification.

Even with such a configuration, the fluid A is mixed by flowing through the communicating first through hole 22 inside each of the mixtures 2a to 2d in the extending direction of the mixing element 21. In the second modification, since the outer diameter of the mixing element 21 and the outer diameter of the second plate 4 are substantially the same as the inner diameter of the casing 50, it is easy to install these casings 50 inside, and the mixing is performed. Since the element 21 does not have the second through hole 23, it is easy to manufacture.

The static mixing device 5 used in the fluid mixing method according to the present invention is not limited to the above-mentioned static mixing device 5 form and each modification as in the form of the mixing unit 1 and each modification. It can be modified and carried out within the scope of the invention. For example, the outer peripheral shapes of the mixing element 21, the first plate 3, and the second plate 4 are not particularly limited to a circular shape. This is because even if the outer peripheral shape is not circular, there is no problem in carrying out any of the inventions.

(Embodiment)
(Experiment 1)
The results of measuring the mixed state of the fluid mixing method according to the present invention are shown below. FIG. 15 (a) is an experimental device used for measuring the mixed state, and FIG. 15 (b) shows the mixing degree bm which is a judgment index of the mixed state.

Used in the static mixer disclosed in Patent Document 1 (hereinafter referred to as "Kenix type static mixer") or the method for mixing the fluid of the present application in the mixer mounting portion shown in FIG. 15 (a). After installing a mixing unit 1 and supplying a predetermined flow of water from the upstream through a PVC pipe with an inner diameter of 25 mm to stabilize the water flow, a highly viscous aqueous solution colored by a microfeeder (not shown) is placed in the water flow. Infused. A transparent acrylic pipe with an inner diameter of 25 mm, which is the same as the upstream PVC pipe, is installed downstream of the Kenix-type static mixer or mixing unit 1, and is irradiated with laser sheet light having a wavelength of 532 nm. An image of the mixed state of the colored highly viscous solution was taken with a high-speed video camera.

The Kenix type static mixer is equipped with six sets of 41 mm long mixing elements in a pipe having an inner diameter of 27 mm, and has a total length of 275 mm including a flange portion. The mixing unit 1 is a set of two mixing elements 21k and 21m having an outer diameter of 21 mm, an inner diameter of 14 mm, and a thickness of 1 mm shown in FIGS. 16A and 16B. Five sets are arranged upstream and downstream of each, and the first plate 3 is arranged at both ends thereof. The inner diameter of the second plate 4 is 14 mm, which is the same as the inner diameter of the mixing element 21, and the outer diameter of the first plate 3 is 21 mm, which is the same as the outer diameter of the mixing element 21. 16 (c) is a plan view showing a state in which the mixed elements 21 shown in FIGS. 16 (a) and 16 (b) are laminated, and the mixed elements 21 of FIG. 16 (a) are colored for the sake of clarity. Is shown. As the highly viscous aqueous solution, CMC2260 manufactured by Daicel Corporation was dissolved in water and colored with Rhodamine B manufactured by Wako Pure Chemical Industries, Ltd. was used.

In FIG. 15B, the inside of the circular portion is an image of a cross section of a transparent acrylic pipe irradiated with laser sheet light taken by a high-speed video camera processed by an image processing program. The horizontal axis of the histogram is the brightness b of the fluorescent region, the vertical axis is the number of pixels n, and the histogram shows the number of pixels n of each brightness b in the image inside the circular portion. By another measurement, it is clear that the brightness b is low when the concentration of the colored highly viscous aqueous solution is low, and conversely, the brightness b is high when the concentration is high. Therefore, a pixel having a high luminance b indicates an unmixed region having a high concentration of a highly viscous aqueous solution, and a pixel having a low luminance b indicates a good mixed region having a low concentration of a highly viscous aqueous solution. If the brightness of all the pixels in the image of the pipe cross section is averaged, the mixing index will be applied to the good mixing area. Therefore, the average value of the brightness of the top 50% of all pixels from the high brightness side. Was used as a judgment index of the mixed state with the mixing degree bm.

Table 1 shows the water flow rate of 0.5 m / sec. The CMC concentration in the colored highly viscous aqueous solution was 0.75% by weight (viscosity of about 300 mPa · s), and the mixing degree bm at the colored highly viscous aqueous solution concentration of 0.2% by weight with respect to water was shown. Table 2 shows the mixing degree bm when the CMC concentration in the colored highly viscous aqueous solution was changed to 1.5% by weight (viscosity of about 1000 mPa · s) from the experimental conditions of Table 1.

Regarding the mixing degree bm calculated from the cross-sectional images from Tables 1 and 2, the bm at the outlet of the mixing unit 1 is lower than the bm at the outlet of the Kenix-type static mixer, and the mixing unit 1 is a Kenix-type static mixer in terms of fluid mixing performance. It can be seen that the mixing performance is superior to that of the target mixer. This is because the Kenix type static mixer only divides the fluid into two planes by a mixing element that exists as one straight line that passes through the center of the pipe axis and divides the cross section of the pipe into two, whereas the mixing unit 1 This is because the fluid is not only divided and merged two-dimensionally (planar) in the radial direction, but also divided and merged in the layer thickness direction of the mixing element 21, and the fluid is divided and merged three-dimensionally. Is. Since the difference in the flow rates between the water and the colored highly viscous aqueous solution is large, the difference in the mixing degree bm is remarkable.

The experimental results shown in Tables 1 and 2 show the mixing degree bm when the concentration of the colored highly viscous aqueous solution with respect to water is 0.2% by weight, but it may be higher or lower than 0.2% by weight. The viscosity of the colored highly viscous aqueous solution is about 300 to 1000 mPa · s, but may be higher or lower than about 300 to 1000 mPa · s.

(Experiment 2)
In Experiment 2, the ratio of ultra-low concentration or ultra-small flow rate in which the concentration of the colored highly viscous aqueous solution (CMC2260 manufactured by Daicel Co., Ltd., CMC concentration 0.75% by weight in the colored highly viscous aqueous solution) is 0.01% by weight with respect to water. The mixing characteristics were evaluated in the case of mixing in.
Here, the coloring substance Rhodamine B (manufactured by Wako Pure Chemical Industries, Ltd.) may dissolve quickly in water and do not have the same diffusion behavior as the highly viscous aqueous solution. The existence may not be extracted. Therefore, as the coloring substance, KRC-F030 manufactured by Kurachi Co., Ltd., which is a hydrophobic substance, was used instead of Rhodamine B. In addition, when taking an image of a pipe cross section, the brightness may show a constant value even in a portion where there is no coloring substance due to the characteristics of the digital camera, so the brightness (0 to 255) of all the pixels of the pipe cross section image is the threshold value. 30 or more pixels (pixels) were designated as fluorescent pixels. Furthermore, the following evaluation indexes (dispersity, median concentration, maximum concentration, size of thick mass, uneven distribution) were defined for determining the mixed state. Others were carried out by the same experimental method as in Experiment 1 above.

(1) Dispersity: M
The degree of dispersion M was defined as the number of fluorescent pixels expressed as a percentage of the total number of pixels in the cross section of the pipe. This degree of dispersion M is an index showing the spread of the fluid due to mixing in the pipe, and it can be evaluated that the higher the degree of dispersion M is, the higher the mixing performance of the fluid is.

(2) Central concentration: bmed
The median brightness of the fluorescent pixels was defined as the median density bmed. This central concentration bmed is less affected by outliers than the average value of the brightness of fluorescent pixels and can be said to be a typical brightness of an image. Therefore, it is an index showing the representative concentration of a fluid due to mixing. It can be evaluated that the mixing performance of is high.

(3) Maximum concentration: b'max
We define n'(b) = n (b) ^{b / 255} , which is exponentially weighted to the number of pixels n (b) of each luminance (b = 0 to 255), and n'(b) is the maximum. The brightness was defined as the maximum density b'max. This maximum concentration b'max is an index indicating the presence of a thick mass with high brightness, and it can be evaluated that the smaller the maximum concentration b'max is, the higher the mixing performance of the fluid is.

(4) Size of thick mass: L
Based on n'(b) used in determining the maximum concentration b'max, the number of fluorescent pixels of each thick mass extracted with the central concentration bmed + 30 as the threshold value is used as a percentage of the total number of pixels in the pipe cross section. The one represented was taken as the size L of the thick mass. In this case, 5 pieces were extracted in descending order of the size L of the thick mass. It can be evaluated that the smaller the size L of the thick mass is, the higher the mixing performance of the fluid is.

(5) Uneven distribution: Dev.
When other fluids with different specific densities are mixed with the mainstream fluid, the other fluids mixed according to the difference in specific densities are unevenly distributed and exist in a certain size (lump), which indicates the bias of the lumps. The uneven distribution degree Dev. Was obtained as an index as follows.
Position information p of -1 to 1 is given from the lower part to the upper part for each pixel of the image of the pipe cross section.
Since the uneven distribution of other fluids to be mixed appears as a concentration difference, p'= b / bmax weighted by the luminance is obtained for each position information p. Here, bmax is the maximum value of the luminance b in each image. Since p'becomes higher as the concentration of the mixed fluid mass increases and the distance from the center increases, the maximum value p'max and the minimum value p'min are obtained for the p'of each pixel. In order to reflect the size of the mass, the median value of p'is calculated for the pixels with the maximum value p'max ± 0.5 and the pixels with the minimum value p'min ± 0.5, and p'max ± _0.5 respectively. , _{P'min ± 0.5} . Since the degree of uneven distribution depends on the number of fluorescent pixels, 2.5% of the number of fluorescent pixels is set to n _2.5 , and the number of pixels with p'= p'max ± 0.5 is set to n _{max ± 0.5} . For p'max, c and p'min corrected using n _2.5 , p'min and c are obtained in the same manner as follows.

Then, the sum of p'max, c and p'min, c was defined as the degree of uneven distribution Dev. This uneven distribution degree Dev. Is a value from -1 to 1, and it can be evaluated that the mass of other fluids mixed is unevenly distributed as the absolute value approaches 1, while it is mixed as the absolute value approaches 0. It can be evaluated that the uniformization of the fluid is progressing and the mixing performance of the fluid is high.

In the experiment, the above evaluation index was obtained for 10 images in which many fluorescent pixels appeared among the images of the pipe cross section, and the average value was obtained. Table 3 shows the results of the evaluation indexes. The size L of the thick mass was the largest.

From Table 3, there was no significant difference in the central concentration and the degree of uneven distribution between the Kenix-type static mixer and the mixing unit (Example). Regarding the degree of dispersion, it can be seen that the mixing unit is higher than the Kenix type static mixer and has excellent fluid diffusion performance. Also, since the mixing unit was lower than the Kenix-type static mixer in terms of maximum concentration, and the mixing unit was smaller than the Kenix-type static mixer in the size of the thick mass, the mixing unit was Kenix. It can be seen that the fluid splitting performance is superior to that of the type static mixer. Therefore, it was found that the mixing unit exhibits superior mixing performance to the Kenix type static mixer in the method of mixing a fluid having a low concentration or a small flow rate in which the fluid to be mixed is 0.01% by weight.

(Experiment 3)
In Experiment 3, glycerin (viscosity of about 880 mPa · s), which is more compatible with water than the carboxymethyl cellulose (CMC2260) aqueous solution, was used as the colored highly viscous aqueous solution, and the concentration of glycerin (colored highly viscous aqueous solution) with respect to water was used. The mixing characteristics were evaluated when the mixture was mixed at a ratio of 0.01% by weight.
As the coloring substance of glycerin, Rhodamine B manufactured by Wako Pure Chemical Industries, Ltd. was used. In addition, the mixing characteristics were evaluated by the degree of dispersion, the median concentration, and the maximum concentration in order to judge the mixing state. Others were carried out by the same experimental method as in Experiment 2 above. Table 4 shows the results of the evaluation indexes.

From Table 4, the dispersity of glycerin was 100% even without a mixer, and the glycerin was quickly dissolved in water. It can be seen that the mixing unit is smaller than the Kenix-type static mixer in terms of the central concentration and the maximum concentration, and has high performance of evenly distributing the fluid and finely dividing the fluid. Therefore, it was found that the mixing unit exhibits excellent mixing performance even in a method of mixing fluids having a low concentration or a small flow rate and high compatibility.

(Experiment 4)
In Experiment 4, edible oil (manufactured by Nisshin Oillio Co., Ltd.), which is a fluid hydrophobic with water, was used as the colored highly viscous fluid, and the edible oil was mixed at a ratio of 0.01% by weight with respect to water. In this case, the vertical diameter (particle size) of the concentrated edible oil mass in the photographed image of the pipe cross section was measured, and the mixing characteristics were evaluated.
Table 5 shows the particle size of cooking oil. In the table, D10 is a particle size with a cumulative frequency of 10% in the particle size distribution, D50 is a particle size with a cumulative frequency of 50% (median diameter) in the particle size distribution, and D90 is a particle size with a cumulative frequency of 90 in the particle size distribution. % Particle size.

When observing the image of the pipe cross section, the thick mass of cooking oil (colored highly viscous fluid) was present in the upper part of the pipe without the mixer, but it was small in the whole in the Kenix type static mixer, and in the mixing unit. It was further subdivided into the whole.
From Table 5, it can be seen that the particle size of the cooking oil is smaller than that of the Kenix type static mixer in all of D10, D50, and D90, and the cooking oil is excellent in the ability to be subdivided. Further, in the mixing unit, D10, D50, and D90 approach each other and show a sharp particle size distribution, which means that the cooking oil is becoming finer and more uniform. Therefore, it was found that the mixing unit exhibits excellent mixing performance even in a method of mixing a hydrophobic fluid such as water and oil at a low concentration or a small flow rate.

(others)
The fluid A to be mixed is not limited to a gas or a liquid, but may be a mixture of a gas and a liquid, a mixture of a gas or a liquid and a solid such as a granular substance, or the like.

Applications include operations such as neutralization that requires mixing a small flow rate fluid into a large flow rate fluid, dissolution of a liquid flocculant in water treatment, and mixing of trace components such as fragrances in a beverage. Further, in addition to the application of making the concentration distribution of each component in the fluid uniform, for example, it can be applied to the application of mixing the same kind of fluid having different temperatures to make the temperature uniform.

It should be considered that the embodiments disclosed above are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims, not by the above embodiments, and includes all modifications and modifications within the meaning and scope equivalent to the scope of claims.

1 Mixing unit 2 Mixer 3 First plate 4 Second plate 5 Static mixing device 21 Mixing element 22 First through hole 23 Second through hole 24 Hollow part 41 (of the second plate) Through hole 55 Circular space A, B fluid

Claims (7)

A high-viscosity aqueous solution colored with a fluorescent colorant is injected into a water stream flowing through a pipe installed upstream of the mixing device, mixed by the mixing device, and is transparent downstream of the mixing device and having the same inner diameter as the piping on the upstream side. A pipe is installed, a fluid mixed by the mixing device is allowed to flow in the transparent pipe, a laser sheet light is irradiated from the pipe radial direction of the transparent pipe, a pipe cross-sectional image of the transparent pipe is taken by a camera, and the pipe is taken. A mixing performance measuring method in which a cross-sectional image is processed as a circular image by an image processing program to obtain pixel brightness, and the brightness of pixels equal to or higher than a predetermined threshold value is used as a judgment index for a mixed state of the fluid. In the mixing performance measuring method according to claim 1,
A mixing performance measuring method in which the average value of the brightness of the top 50% of the pixels from the high brightness side of all the pixels of the circular image is set as the mixing degree bm and used as a judgment index of the mixing state of the fluid. In the mixing performance measuring method according to claim 1 or 2.
Of all the pixels of the circular image, the pixels whose brightness is equal to or higher than the predetermined threshold value are defined as fluorescent pixels.
A mixing performance measuring method in which the number of pixels of the fluorescent pixels is expressed as a percentage of the total number of pixels of the circular image as the dispersion degree M, and the dispersion degree M is used as an index indicating the spread of a fluid due to mixing. In the mixing performance measuring method according to any one of claims 1 to 3,
Of all the pixels of the circular image, the pixels whose brightness is equal to or higher than the predetermined threshold value are defined as fluorescent pixels.
A mixing performance measuring method in which the median value of the brightness of the fluorescent pixel is defined as the median concentration bmed, and the median concentration bmed is used as an index representing the representative concentration of the fluid by mixing. In the mixing performance measuring method according to any one of claims 1 to 4.
We define n'(b) = n (b) ^{b / 255} , which is exponentially weighted to the number of pixels n (b) at each luminance (b = 0 to 255) of all the pixels of the circular image. A mixing performance measuring method in which the brightness at which n'(b) is maximized is defined as the maximum density b'max, and the maximum density b'max is used as an index indicating the presence of a thick mass. In the mixing performance measuring method according to any one of claims 1 to 5,
Of all the pixels of the circular image, the pixels whose brightness is equal to or higher than the predetermined threshold value are defined as fluorescent pixels.
Based on n'(b) = n (b) ^{b / 255} , which is exponentially weighted with respect to the number of pixels n (b) at each brightness (b = 0 to 255) of all the pixels of the circular image. The median value of this n'(b) is defined as the median concentration bmed, and the number of fluorescent pixels is expressed as a percentage of the total number of pixels of the circular image for each thick mass extracted with the median concentration bmed + 30 as a threshold value. A mixing performance measuring method in which the size of the thick mass is L. In the mixing performance measuring method according to any one of claims 1 to 6,
Of all the pixels of the circular image, the pixels whose brightness is equal to or higher than the predetermined threshold value are defined as fluorescent pixels.
When other fluids with different specific densities are mixed with mainstream water, the eccentricity Dev. Mixing performance measurement method obtained in this way.
Position information p of -1 to 1 is given to each pixel of the circular image from the lower part to the upper part, and p'= p · b / bmax weighted by the luminance is obtained for each position information p (here, bmax). Is the maximum value of the luminance b in each image .).
The maximum value p'max and the minimum value p'min are obtained for the p'of each pixel, and the center of p'for the pixel with the maximum value p'max ± 0.5 and the pixel with the minimum value p'min ± 0.5. Calculate the values and set them as p'max _± 0.5 and _{p'min ± 0.5} , respectively.
2.5% of the number of fluorescent pixels is n _2.5 , the number of pixels of p'max ± 0.5 is n _{max ± 0.5} , and the number of pixels of p'min ± 0.5 is n _{min ± 0.5} . On the other hand, p'max, c corrected using n _2.5 and p'min, c corrected using n _2.5 with respect to p'min were obtained for each case as follows, and p'max, Let the sum of c and p'min, c be the uneven distribution degree Dev. Indicated by a value from -1 to 1.

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