Method for improving identification degree of low-luminosity dispersed-phase particles in multiphase system

Abstract

The present invention provides a method for improving an identification degree of low-luminosity dispersed-phase particles in a multiphase system. The method comprises: adding additive particles into a multiphase system containing low-luminosity dispersed-phase particles before photographing the multiphase system to obtain an image including the low-luminosity dispersed-phase particles, wherein the refractivity of the additive particles is greater than that of the low-luminosity dispersed-phase particles. The method can enhance the luminosity of the continuous phase in the multiphase system, thereby causing a large gray difference between the continuous phase and the dispersed-phase particles, improving the identification degree of the low-luminosity dispersed-phase particles in the image for conducting accurate identification by image analysis software and further being capable of accurately measuring needed parameters such as particle size, concentration or speed and the like of the dispersed-phase particles in a multiphase reactor.

Claims

1. A method for improving an identification degree of low-luminosity dispersed-phase particles in a multiphase system, comprising: adding additive particles into a multiphase system containing low-luminosity dispersed-phase particles before photographing the multiphase system to obtain an image including the low-luminosity dispersed-phase particles, wherein the refractivity of the additive particles is greater than that of the low-luminosity dispersed-phase particles, and wherein the low-luminosity dispersed-phase particles are particles with a refractivity that meets the following conditions: the real part is less than 1.5, and the imaginary part is more than 0.5.

2. The method according to claim 1, wherein the method further comprises: carrying out analysis processing on the image of the low-luminosity dispersed-phase particles to obtain parameters of particle size, concentration or speed of the dispersed-phase particles in the multiphase system.

3. The method according to claim 1, wherein the refractivity of the additive particles is 2.0 times or greater that of the low-luminosity dispersed-phase particles.

4. The method according to claim 1, wherein the concentration of the additive particles in the multiphase system is 5 mg/L-7 mg/L.

5. The method according to claim 1, wherein the particle size of the additive particles is 100 nm-10 m.

6. The method according to claim 1, wherein the color of the additive particles belongs to a bright color system.

7. The method according to claim 1, wherein the color of the additive particles is white.

8. The method according to claim 1, wherein the additive particles are particles with a scattering angle of 90-270 degrees calculated according to the Mie scattering theory.

9. The method according to claim 1, wherein the additive particles are selected from any one or a combination of at least two of titanium dioxide particles, silicon dioxide particles or aluminum oxide particles.

10. The method according to claim 1, wherein the concentration of the low-luminosity dispersed-phase particles in the multiphase system is 50 wt % or less.

11. The method according to claim 1, wherein the low-luminosity dispersed-phase particles are selected from bubbles and/or solid particles.

12. The method according to claim 1, wherein the photographing is immersive photographing.

13. The method according to claim 1, wherein an immersive online multiphase measuring instrument is used for photographing the low-luminosity dispersed-phase particles in the multiphase system.

14. The method according to claim 1, wherein a gas-liquid multiphase system or a liquid-solid multiphase system is used as the multiphase system.

15. The method according to claim 1, wherein the method comprises the following steps: adding white additive particles with a scattering angle of 90-270 degrees calculated according to the Mie scattering theory to a multiphase system containing the low-luminosity dispersed-phase particles before carrying out immersive photographing on the multiphase system to obtain an image including the low-luminosity dispersed-phase particles, wherein the refractivity of the additive particles is 2.0 times or greater that of the low-luminosity dispersed-phase particles, the concentration of the additive particles in the multiphase system is 5 mg/L-7 mg/L, the particle size of the additive particles is 100 nm-10 m, and the concentration of the low-luminosity dispersed-phase particles in the multiphase system is 50 wt % or less.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram illustrating the structure of an immersive online multiphase measuring instrument provided by Example 1;

(2) In the figure: 1. window; 2. LED lamp; 3. stainless-steel packaging pipe; 4. telecentric lens; 5. miniature high-speed CMOS camera; 6. modulating light source; 7. wire; 8. USB3.0 data transmission line; 9. high-speed image acquisition card; and 10. sampling computer.

(3) FIG. 2 is a schematic diagram illustrating a control mode provided by Example 1;

(4) FIG. 3 is an image illustrating a gas-liquid system obtained through illumination of an immersive probe and a same-direction light source (i.e., an illuminating system in an immersive online multiphase measuring instrument) in Example 1;

(5) FIG. 4 is an image illustrating a gas-liquid system obtained through illustration of an immersive probe and the backside light source (i.e., back illustration outside a reactor) in Example 1;

(6) FIG. 5 is an image illustrating a gas-liquid system obtained by adopting an immersive probe and adding a reflecting board on the back (i.e., the reflecting board is connected with the probe by two thin and long supporting feet, and fluid to be measured flows through a gap between the two supporting feet) in Example 1;

(7) FIG. 6 is an image illustrating a gas-liquid system obtained by adopting an immersive probe and adding silicon dioxide particles in Example 1;

(8) FIG. 7 is an image illustrating a gas-liquid system obtained by adopting an immersive probe and adding aluminum oxide particles in Example 1;

(9) FIG. 8 is an image illustrating a gas-liquid system obtained by adopting an immersive probe and adding titanium dioxide particles in Example 1;

(10) FIG. 9a is a comparison diagram illustrating bubble size distributions in contrast experiments under the conditions of addition of titanium dioxide, addition of reflecting board and back brightening provided by (1) in Example 3;

(11) FIG. 9b is a comparison diagram illustrating bubble size distributions in contrast experiments under the conditions of addition of titanium dioxide, addition of reflecting board and back brightening provided by (2) in Example 3;

(12) FIG. 9c is a comparison diagram illustrating bubble size distributions in contrast experiments under the conditions of addition of titanium dioxide, addition of reflecting board and back brightening provided by (3) in Example 3; and

(13) FIG. 9d is a comparison diagram illustrating bubble size distributions in contrast experiments under the conditions of addition of titanium dioxide, addition of reflecting board and back brightening provided by (4) in Example 3.

DETAILED DESCRIPTION

(14) The technical solution of the present invention is further described in combination with drawings and specific embodiments.

(15) A method for improving an identification degree of low-luminosity dispersed-phase particles in a multiphase system comprises: white additive particles with a scattering angle of 90-270 degrees calculated according to Mie scattering theory are added into a multiphase system containing low-luminosity dispersed-phase particles before immersive photographing is carried out on the multiphase system to obtain an image including the low-luminosity dispersed-phase particles, wherein the refractivity of the additive particles is 2.0 times or greater that of the low-luminosity dispersed-phase particles; the concentration of the additive particles in the multiphase system is 5 mg/L-7 mg/L; the particle size of the additive particles is 100 nm-10 m; and the concentration of the low-luminosity dispersed-phase particles in the multiphase system is 50 wt % or less.

Example 1: Acquiring Image of Dispersed Phase in Gas-Liquid System by Utilizing Immersive Online Multiphase Measuring Instrument

(16) The immersive online multiphase measuring instrument, as shown in FIG. 1, includes:

(17) a stainless-steel packaging pipe 3;

(18) a window 1 connected to one end of the stainless-steel packaging pipe 3 in a sealing manner;

(19) an illuminating system for illuminating a multiphase flow, including LED lamps 2 and a modulating light source connected with the LED lamps 2, wherein the modulating light source includes a power supply, a signal generator and an oscilloscope;

(20) a photographic system for photographing, including a telecentric lens 4 and an image sensor which is a miniature high-speed CMOS camera 5;

(21) a controller connected with the signal generator and the image sensor;

(22) a signal processing and output system connected with the image sensor; and

(23) a display system connected with the signal processing and output system,

(24) wherein the LED lamps, the telecentric lens and the image sensor are positioned in the stainless-steel packaging pipe, and the modulating light source, the controller, the signal processing and output system and the display system are positioned outside the stainless-steel packaging pipe; and the controller controls an exposure period of the image sensor to be shorter than a pulse period of the signal generator.

(25) The signal processing and output system, the controller and the display system are integrated into a sampling computer 10.

(26) Specifically, the window 1 is arranged at the most front end of the stainless-steel packaging pipe 3, and is round sapphire glass with an inner side plated with an antireflection film; 20 high-luminosity LED lamps 2 are uniformly distributed behind the window 1, form a ring shape and are uniformly distributed; the telecentric lens 4 is arranged at the rear end of the LED lamps 2, and related parameters of the telecentric lens include: magnification is 1, vision fields of an object and image are respectively 8 mm ( is diameter), a working distance is 250 mm3%, the telecentricity is less than 0.1 degree, a depth of field is 2.1 mm, a resolution is 14.3 m, optical distortion is less than 0.12%. For clear imaging, the distance from the front end of the telecentric lens 4 to a surface of an outer side of the window 1 is the working distance of the telecentric lens. The telecentric lens 4 is connected with the miniature high-speed CMOS camera 5 by a standard C port, and parameters of the CMOS camera include: a resolution is 12801024, colors are black and white, a frame rate is 150 fps, and an interface is USB3.0. The window 1, the LED lamps 2, the telecentric lens 4 and the miniature high-speed CMOS camera 5 are packaged in the stainless-steel packaging pipe 3. A modulating light source 6 is configured outside the online multiphase measuring instrument, and is connected with the LED lamps 2 by a wire 7. The telecentric lens 4 is connected with a sampling computer 10 provided with a high-speed image acquisition card 9 by a USB3.0 data transmission line 8.

(27) In order to obtain clear images, a control mode shown in FIG. 2 is adopted to realize the synchronization of illumination flashing and CMOS photographing and the control mode is as follows: a switch of a light source is turned on; the intensity and a period of pulse light are set by a light source driver; the exposure time, light balance, frame frequency and gain of image shooting are set by the controller on a computer to match the pulse period of an illuminating signal with the exposure time of the image sensor (the exposure period of the image sensor is shorter than the pulse period of the signal generator) so as to realize the synchronization of pulse light and image shooting.

(28) Image acquisition is carried out in a square organic glass stirring groove with a length T of 0.17 m, a width T of 0.17 m and a height H of 0.23 m, and the stirring speed is 200 rpm. The height H of a static liquid level is equal to T, a stirring paddle is a Rushton paddle, a diameter D of the paddle is equal to T/3, 4 blocking plates are uniformly distributed around the stirring groove, and a width B of each blocking plate is equal to T/10. The length t, width t and height z (same as the coordinate system of the square organic glass stirring groove) of the measured point are respectively equal to 0.05 m, 0.05 m and 0.14 m. Gas is fed by a sintering ceramic hole distributor and the ventilation volume is 120 L/h.

(29) The immersive online multiphase measuring instrument is utilized for acquiring images of the dispersed-phase particles in the gas-liquid system respectively under the following illuminating conditions:

(30) (1) Under the condition that only front light irradiation is provided, the secondary exposure image at the measured point is acquired to obtain an image, as shown in FIG. 3.

(31) (2) Under the condition that the front light and back light are provided, the secondary exposure image at the measured point is acquired to obtain an image, as shown in FIG. 4.

(32) (3) Under the condition that the front light and the reflecting board are provided, the secondary exposure image at the measured point is acquired to obtain an image, as shown in FIG. 5.

(33) (4) Under the condition that the front light and silicon dioxide particles are provided, an image at the measured point is acquired to obtain an image, as shown in FIG. 6.

(34) (5) Under the condition that the front light and aluminum oxide particles are provided, an image at the measured point is acquired to obtain an image, as shown in FIG. 7.

(35) (6) Under the condition that the front light and titanium dioxide particles are provided, an image at the measured point is acquired to obtain an image, as shown in FIG. 8.

(36) Properties of the additive particles added in (4), (5) and (6) are shown in the following Table 1.

(37) TABLE-US-00001 TABLE 1 Physical Property Data of All Additive Particles and Concentrations in Multiphase System Type of Wave- refrac- Particle Particles length tivity Color Size Concentration Aluminum 580 nm 1.76 White 0.5-1.5 m 5 mg/L Oxide Titanium 580 nm 2.62 White 0.5-1.5 m 5 mg/L Dioxide Silicon 580 nm 1.45 White 0.5-1.5 m 5 mg/L Dioxide

(38) By analysis on the images, it can be discovered that the addition of the reflecting particles actually plays a role in improving luminosity of the dispersed phase and the continuous phase in the flow field and the effect is best after the addition of the titanium dioxide particles.

(39) In addition, the particle sizes of all the additive particles in (4), (5) and (6) are adjusted to be any value between 100 nm and 10 m, such as 150 nm, 200 nm, 230 nm, 280 nm, 310 nm, 400 nm, 500 nm, 800 nm, 900 nm, 1 m, 3 m, 5 m, 8 m or 9 m and the like; images at measured points are acquired, and bubble images with high resolution can be still obtained.

(40) The concentrations of all the additive particles in (4), (5) and (6) in the multiphase system are adjusted to be any value between 5 mg/L and 7 mg/L, such as 5.1 mg/L, 5.2 mg/L, 5.3 mg/L, 5.5 mg/L, 5.8 mg/L, 6.2 mg/L, 6.5 mg/L, 6.8 mg/L or 6.9 mg/L and the like; images at measured points are acquired, and bubble images with high resolution can be still obtained.

Example 2: Measuring Change Conditions of Viscosity, Density and Surface Tension of Continuous Phase Before and After Addition of Reflecting Particles

(41) Under the experimental conditions of (5) in Example 1, the change conditions of viscosity, density and surface tension before and after addition of the titanium dioxide particles are measured, as shown in Table 2.

(42) TABLE-US-00002 TABLE 2 Changes of Physical Properties of Continuous Phase before and after Addition of Titanium Dioxide Density Viscosity Surface Tension Types Concentration (g/cm.sup.3) (mpa .Math. s) (Average) mN/m Water 1.00220 0.8971 71.64 TiO.sub.2 5 mg/L 1.00249 0.9294 71.95

(43) According to data analysis of the above table, picture photographing requirement can be met only by a small quantity of titanium dioxide, and the properties of the continuous phase are almost unchanged (all the errors are less than 5%).

Example 3

(44) The following experiments are carried out respectively in the stirring groove provided in Example 1:

(45) (1) The rotating speed of the stirring paddle is 0 rpm, the ventilation volume is 80 L/h; the length t, the width t and the height z (same as the coordinate system of the square organic glass stirring groove) at the measured point are respectively 0.05 m, 0.05 m and 0.14 m; contrast experiments are conducted respectively under the conditions of back brightening, addition of reflecting board and addition of titanium dioxide (with a concentration of 5 mg/L) shown in Table 2 in a water-air system; particle size distribution at the measured point is acquired; and measurement results are shown in FIG. 9a .

(46) (2) The rotating speed of the stirring paddle is 200 rpm, the ventilation volume is 80 L/h; the length t, the width t and the height z at the measured point are respectively 0.05 m, 0.05 m and 0.14 m; contrast experiments are conducted respectively under the conditions of back brightening, addition of reflecting board and addition of titanium dioxide (with a concentration of 5 mg/L) shown in Table 2 in a water-air system; particle size distribution at the measured point is acquired; and measurement results are shown in FIG. 9b.

(47) (3) The rotating speed of the stirring paddle is 0 rpm, the ventilation volume is 120 L/h; the length t, the width t and the height z (same as the coordinate system of the square organic glass stirring groove) at the measured point are respectively 0.05 m, 0.05 m and 0.14 m; contrast experiments are conducted respectively under the conditions of back brightening, addition of reflecting board and addition of titanium dioxide (with a concentration of 5 mg/L) shown in Table 2 in a water-air system; particle size distribution at the measured point is acquired; and measurement results are shown in FIG. 9c.

(48) (4) The rotating speed of the stirring paddle is 200 rpm; the ventilation volume is 120 L/h; the length t, the width t and the height z (same as the coordinate system of the square organic glass stirring groove) at the measured point are respectively 0.05 m, 0.05 m and 0.14 m; contrast experiments are conducted respectively under the conditions of back brightening, addition of reflecting board and addition of titanium dioxide (with a concentration of 5 mg/L) shown in Table 2 in a water-air system, particle size distribution at the measured point is acquired, and measurement results are shown in FIG. 9d.

(49) It can be seen from FIG. 9a to FIG. 9d that the measurement results of the method of adopting the additive particles in the present invention are more accurate.

(50) The applicant declares that, the above only describes specific embodiments of the present invention, but the protection scope of the present invention is not limited to the above. Those skilled in the art should understand that any modification or replacement which can be easily contemplated by those skilled in the art within the technical scope disclosed by the present invention is included in the protection scope and disclosure scope of the present invention.