JP4022617B2 - Method and apparatus for producing pseudo spray droplets - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for generating pseudo-spray droplets that have specific particle properties and that do not change in time series and are composed of stable solid particles. It can be used as a standard that guarantees reliability.
[0002]
[Prior art]
What is indispensable for the development of atomization technology is spray droplet measurement technology. Spray droplet measurement belongs to the most difficult measurement category in terms of accuracy and reliability, and recently, measurement methods based on various optical principles are widely used. However, each method has advantages and disadvantages, and when data obtained by different principles and measurement methods are compared with each other, a good agreement is not always found (Non-Patent Document 1). Furthermore, even for measuring instruments based on the same principle, the difference between models and individuals often becomes so large that it cannot be ignored.
The necessity of a standard is widely recognized as one used to ensure consistency between such various methods and apparatuses. The standard requires that the particle properties such as the size, shape, or refractive index of individual particles, as well as the particle size distribution and number density that characterize the group of particles are clear. However, particle properties such as particle size distribution are greatly affected and unstable due to many factors such as spray nozzle shape, size of atomization energy, environmental conditions such as humidity and temperature, etc. Since the particle diameter changes from moment to moment, the test particles composed of a liquid are difficult to use as a standard for spray droplets. On the other hand, the test particles composed of solid particles have a clear particle property and are stable with no time-series change. However, the solid particles having a primary particle size of several microns or less are highly agglomerated. Since a plurality of primary particles aggregated to form higher-order aggregates, it was difficult to generate and disperse them in the gas as test particles (Non-patent Document 2). In addition to the laser diffraction method, there are examples of using test samples (reticles) on which various particle images are baked on a glass substrate, but there are only problems with the shape and number of the baked particle images. In addition, there is a drawback that data cannot be compared with other principles and measurement methods.
Thus, the spray droplet measuring accuracy and become a standard, such as the reliability can be guaranteed to give Ru injection Kiriekishizuku, the method and the manufacturing apparatus is not yet there, resulting Ru injection Kiriekishizuku become the early standard A manufacturing method and a manufacturing apparatus are desired.
[0003]
[Non-Patent Document 1]
Kurabayashi, Liquid atomization technology, IPC (1995)
[Non-Patent Document 2]
Y. Kousaka, T. Horiuchi, Y. Endo and S. Aotani, Aerosol Science and Technology 21 (1994) 236-240.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide, as a spray droplets available as standard, Ru der to provide a pseudo-atomized droplets composed of solid particles. Also, the solid particles by generating distributed, certain solid particles to provide a method and apparatus for producing a pseudo atomized droplets. Here, since the pseudo spray droplet is used as a standard and is composed of solid particles, the particle properties such as the size, shape, and refractive index of each particle are constant, and sometimes It is assumed that no series change occurs.
[0005]
[Means for Solving the Problems]
The inventors of the present invention have made intensive research efforts to solve the above problems and have obtained the following knowledge and have convinced that the above problems can be solved.
It has been found that pseudo-spray droplets composed of solid particles having a constant particle property and no time-series change can be obtained.
By using the pseudo spray droplets, data can be compared between various measurement methods and apparatuses, and can be used as a standard for ensuring consistency.
In general, solid particles of several microns or less exhibit high agglomeration regardless of the material, and under normal environmental conditions, a plurality of primary particles aggregate to form higher-order aggregates. It cannot be used as a pseudo spray droplet. The reason why a pseudo spray droplet that can be used as the standard material as described above can be obtained is that the method for producing the pseudo spray droplet was newly found.
In producing the pseudo spray droplets, when the solid particles of the raw material are suspended in the supercritical fluid, the cause of the cohesion of the solid particles is removed by contacting with the supercritical fluid, or The degree of cohesion is greatly relaxed, causing solid particles to disintegrate, and when the supercritical suspension fluid is released under environmental conditions that vaporize the supercritical fluid, a large expansion force can be obtained when the state changes. It is possible to crush the agglomerates formed by agglomeration of solid particles that are to form pseudo spray droplets using the large expansion force generated with the change of the state, and it is primary to sudden decrease It is possible to generate and disperse the atomized solid particles as spray droplets in a gas obtained by vaporizing a supercritical fluid, and the solid particles of the specific material thus obtained have a constant particle property. Because there is no time-series change, and because it has such characteristics, it can be used as a standard for ensuring consistency by comparing data between various measurement methods and devices. It was something that was found.
[0006]
That is, according to the present invention, the following inventions are provided.
(1) A solid particle, which is a raw material, is suspended in a supercritical fluid to form a supercritical suspended fluid, which is discharged under environmental conditions that vaporize the supercritical fluid, and the resulting solid particles It consists group, a constant particle properties, pseudo atomized droplets, characterized in that it consists of particles of time series change no solid particles.
(2) The pseudo spray droplet according to (1), wherein the particle property means the size, shape, refractive index, etc. of each particle.
(3) A solid particle, which is a raw material substance, is suspended in a supercritical fluid to form a supercritical suspended fluid, which is discharged under environmental conditions that vaporize the supercritical fluid, and the resulting solid particles A method for producing pseudo-spray droplets, characterized in that the method comprises a group of solid particles having a constant particle property and no time-series change.
(4) The method for producing pseudo spray droplets according to (3), wherein the particle property means the size, shape, refractive index, etc. of each particle.
(5) A supercritical suspension fluid is formed by suspending solid particles as a raw material in a supercritical fluid, and the supercritical fluid is vaporized by performing an impactor treatment by spraying or after spraying. (3) The method for generating pseudo spray droplets according to (3), characterized in that the particles are discharged under an environmental condition to be obtained, and the resulting particles are a group of solid particles .
(6) A method for generating a pseudo spray droplet according to any one of (3) to (5), wherein a dilution gas is supplied to the pseudo spray droplet and the resulting pseudo spray droplet concentration is controlled. .
(7) The solid particles are suspended in the supercritical fluid, having supply means for supplying the solid particles as the raw material, supply means for supplying the supercritical fluid, and discharge means for discharging the formed supercritical suspension fluid. The supercritical suspension fluid forming tank and the supercritical suspension fluid discharged from the supercritical suspension fluid forming tank are discharged under environmental conditions that vaporize the supercritical fluid, and the solidified in the vaporized supercritical fluid. An apparatus for generating pseudo spray droplets, comprising means for generating and dispersing pseudo spray droplets in a state where particles are dispersed.
(8) The pseudo-spray droplet generator according to (7), wherein the means for generating and dispersing the pseudo-spray droplets comprises an atomizer or an impactor processing unit following the spray nozzle.
(9) The pseudo spray droplet generator according to (7) or (8), wherein a dilution gas supply means for controlling the generation concentration of the pseudo spray droplet is provided.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The pseudo spray droplet of the present invention is configured as a particle group of solid particles having a constant particle property and no time-series change. Here, the particle property means the size, shape, refractive index and the like of each particle. Such particle properties are derived from the properties of the raw materials used and the unique method of producing the particles.
Examples of the raw material include test powder and test particles (JIS Z 8901). In addition, polymers or copolymers obtained from styrene, methacrylic acid esters, tetrafluorinated ethylene, and other vinyl monomers, as well as various polymers or copolymers such as epoxy resins, phenol resins, melanin resins, polyamide resins, and silicone resins. Organic materials such as polymer particles, various metals such as gold, platinum, rhodium, nonmetals such as carbon and silicon, ceramic materials such as silica and alumina, and fullerenes, dendrimers and carbon Supramolecules such as nanotubes can be mentioned. The solid particles made of these raw materials are used in a state where the size is appropriately adjusted. The solid particles obtained as the pseudo spray droplets of the present invention by processing the solid particles by the method of producing the pseudo spray droplets of the present invention have the same properties and no time-series change. It is obtained as
[0008]
The method for producing the pseudo spray droplet of the present invention will be described with reference to FIG.
FIG. 1 is a diagram showing a pseudo spray droplet manufacturing apparatus according to the present invention.
In the production method of the pseudo spray droplets, by using the apparatus described below, it is possible to obtain solid particles having a constant particle property and no time-series change, which is the target substance of the present invention.
The supercritical suspension fluid forming tank 1 has a supply means 4 for supplying a supercritical fluid, a supply means 3 for supplying solid particles made of a raw material, and a discharge means 6 for discharging the formed supercritical suspension fluid.
In this supercritical suspension fluid forming tank 1, a supercritical suspension fluid of solid particles made of a raw material is formed.
The solid particles made of the raw material are supplied through the supply means 3.
The supercritical fluid can be appropriately selected and used. Specific examples include carbon dioxide, nitrogen dioxide, ethane, propane, ethylene, chlorofluorocarbon alternative, and water.
Carbon dioxide, methane, ethylene, chlorofluorocarbons, etc., cleaned through a filter are heated and pressurized to a critical state, and are used as supercritical fluid by supercritical fluid supply means 4 via flow rate adjustment means 5 and supercritical fluid. It is supplied to the suspension formation tank 1.
In this supercritical suspension fluid forming tank 1, for example, a high-speed mixer using a stirring blade or a stirrer or an ultrasonic generator can be installed and used to obtain a suspension fluid that is stirred and mixed.
The contact with the supercritical fluid due to this suspension removes the cause of the cohesive strength of the solid particles forming the pseudo spray droplets, or the degree of cohesion is greatly relaxed and the solid particles are crushed. Can be awakened.
[0009]
The supercritical suspended fluid forming tank 1 has a temperature control jacket 2 around it, and keeps the supercritical fluid in a supercritical state or a subsupercritical state.
A supercritical fluid means a fluid in a supercritical state. The supercritical state is a so-called supercritical state exceeding the critical temperature and critical pressure, as well as such a critical temperature and critical pressure. However, since the state change occurs in a very short time, it includes a subcritical state that can be handled in the same manner as the above supercritical fluid. Including subcritical fluids.
When carbon dioxide is used as the supercritical fluid, it is necessary to maintain the temperature at 30 to 80 ° C., preferably 30 to 50 ° C., and the pressure at 40 to 400 atm, preferably 100 to 300 atm.
[0010]
Next, the supercritical suspension fluid passes through the discharge means 6 for discharging the supercritical suspension fluid, and the flow rate is appropriately adjusted by the flow rate adjustment means 7, and then the supercritical suspension fluid is generated from the pseudo spray droplet generation / dispersion means 8. Released under environmental conditions that vaporize the fluid. By generating and dispersing from the generating and dispersing means 8, it is possible to obtain pseudo spray droplets configured in a state where solid particles having a constant particle property and no time-series change are dispersed.
The pseudo spray droplet generation / dispersion means 8 generally employs a nozzle that is used when generating normal droplets. This nozzle is formed by pores. The size of the pores may be appropriately determined in consideration of the size of the solid particles obtained as a result of spraying.
Furthermore, the spray nozzle which has a temperature control function which can compensate a temperature change can be used for a nozzle. The temperature adjustment function has a temperature control means such as a heater.
As for the nozzle, it is necessary if the nozzle formed by a single tube that sprays the supercritical suspension fluid or the concentration of the pseudo spray droplets to be obtained in addition to the supercritical suspension fluid needs to be adjusted. Accordingly, a two-fluid nozzle formed by a double pipe that can supply a dilution gas can be used. As the dilution gas, clean air, carbon dioxide or the like is appropriately selected and used.
[0011]
As a result of this release, solid particles suspended in the supercritical fluid undergo a rapid volume expansion of the supercritical fluid that has entered the gaps between the particles, causing the aggregates to be crushed and primary particles to be generated. Solid particles having a constant particle property and no time-series change in the vaporized gas of the fluid can be generated and dispersed as pseudo spray droplets.
In the impactor treatment, the fluid containing solid particles from the spray nozzle is struck against the flat plate and the flow direction is bent to remove the remaining aggregates without breaking and primary particles with sufficient inertia. As a result, good generation and dispersion of pseudo spray droplets can be achieved.
The impactor processing means refers to an apparatus capable of hitting a flat plate with fluid containing solid particles sprayed from a nozzle.
[0012]
By performing the above-described treatment using the above-described apparatus, a supercritical suspension fluid formed by suspending solid particles made of a raw material in a supercritical fluid is vaporized into a supercritical fluid. The pseudo spray droplets of the present invention can be produced by being generated and dispersed as pseudo spray droplets in a gas obtained by discharging the supercritical fluid from the supercritical suspension fluid. Further, depending on the solid particles used as a raw material and the amount of suspension of the solid particles in the supercritical fluid, the target substance of the present invention is a particle group consisting of solid particles having a constant particle property and no time-series change. Properties such as particle size distribution and number density can be controlled. Furthermore, the solid particles obtained by generating and dispersing as pseudo spray droplets are a group of particles composed of primary particles.
[0013]
【Example】
The contents of the present invention will be described in more detail with reference to examples.
Example 1
The supercritical fluid supply tank 1 is charged with glass particles having an average particle size of about 10 μm from the solid particle supply means 3 from the solid particle supply means 3, and the supercritical fluid supply means 4 has a temperature of 40 ° C. and a pressure of 100 atm. Supercritical carbon dioxide was introduced and suspended. The glass particles at the time of supply are high-order aggregates having a size of several tens to several hundreds μm.
The suspension is discharged from the supercritical suspension fluid discharging means 6 through the flow rate adjusting means 7 from the pseudo spray droplet generating / dispersing means 8 constituted by a spray nozzle having an equivalent orifice diameter of 0.13 mm. Spray droplets were generated and dispersed. By a light scattering type particle counter, the glass particles, which are high-order aggregates having a size of several tens to several hundreds μm, are dispersed into high-concentration primary particles having an average particle diameter of about 10 μm. It was confirmed that it was generated as a droplet. Furthermore, the glass particles generated and dispersed as pseudo spray droplets were deposited on a slide glass and observed with an optical microscope to confirm that they were dispersed to primary particles. FIG. 2 (a) shows the state of the aggregate of glass particles observed at the time of supply observed with an optical microscope, and FIG. 2 (b) shows the state of the glass particles generated and dispersed by this example.
[0014]
Example 2
In the same manner as in Example 1, 10 mg of primary particles of polymethyl methacrylate particles having an average particle diameter of about 1 μm are charged from the solid particle supply unit 3 into the supercritical suspension fluid forming tank 1, and the supercritical fluid supply unit 4 is added. Then, supercritical carbon dioxide having a temperature of 40 ° C. and a pressure of 100 atm was introduced and suspended. The polymethylmethacrylate particles at the time of supply are higher-order aggregates having a size of several tens to several hundreds μm.
The suspension is discharged from the supercritical suspension fluid discharging means 6 through the flow rate adjusting means 7 from the pseudo spray droplet generating / dispersing means 8 constituted by a spray nozzle having an equivalent orifice diameter of 0.13 mm. Spray droplets were generated and dispersed. The polymethyl methacrylate particles, which were high-order aggregates having a size of several tens to several hundreds of μm, were dispersed into high-concentration primary particles having an average particle diameter of about 1 μm by a light scattering type particle counter. It was confirmed that it was generated as a pseudo spray droplet. Furthermore, polymethylmethacrylate particles generated and dispersed as pseudo spray droplets were deposited on a slide glass and observed with an optical microscope to confirm that they were dispersed to primary particles. FIG. 3A shows the state of aggregates of polymethyl methacrylate particles observed at the time of supply observed with an optical microscope, and FIG. 3B shows the state of polymethyl methacrylate particles generated and dispersed in this example. Show.
[0015]
【The invention's effect】
According to the present invention, it is possible to obtain pseudo spray droplets composed of stable solid particles that have constant particle properties such as the size, shape, and refractive index of each particle and do not change over time. Moreover, the manufacturing method and manufacturing apparatus for obtaining this pseudo spray droplet are obtained.
[Brief description of the drawings]
[Fig. 1] Schematic diagram of pseudo spray droplet generator [Fig. 2] State of glass particles observed with optical microscope (a) Aggregates at the time of supply (b) Primary particles after generation and dispersion [Fig. 3] With optical microscope Observation of polymethylmethacrylate particles (a) Aggregates at the time of supply (b) Primary particles after generation and dispersion
1 Supercritical suspension fluid formation tank
2 Temperature control jacket
3 Means for supplying raw material solid particles
4 Supercritical fluid supply means
5 Flow rate adjustment means
6 Supercritical suspension fluid discharge means
7 Flow rate adjustment means
8 Simulated spray droplet generation and dispersion means

Claims (6)

The solid particles as a raw material substance and a supercritical suspension fluid is formed by suspended in a supercritical fluid, and released into the environment under conditions to vaporize the supercritical fluid, the particles of the resulting solid particles A method for producing pseudo-spray droplets. The solid particles as a raw material substance and a supercritical suspension fluid is formed by suspended in a supercritical fluid environment to vaporize the supercritical fluid by performing impactor processing or after spraying by spraying the supercritical fluid released under the conditions, method of manufacturing the pseudo atomized droplets you, characterized in that the particles of the resulting solid particles. The method for producing pseudo spray droplets according to claim 1 or 2 , wherein a dilution gas is supplied to the pseudo spray droplets, and the resulting pseudo spray droplet concentration is controlled. A supercritical material for suspending solid particles in a supercritical fluid, comprising a supply means for supplying solid particles as a raw material, a supply means for supplying a supercritical fluid, and a discharge means for discharging the formed supercritical suspension fluid The suspension fluid formation tank and the supercritical suspension fluid discharged from the supercritical suspension fluid formation tank are released under environmental conditions that vaporize the supercritical fluid, and solid particles are dispersed in the vaporized supercritical fluid. An apparatus for producing pseudo spray droplets, characterized in that it comprises means for generating and dispersing pseudo spray droplets in a state of being applied. 5. The apparatus for producing pseudo spray droplets according to claim 4, wherein the means for generating and dispersing the pseudo spray droplets comprises a spray nozzle or an impactor processing means following the spray nozzle. 6. The apparatus for producing pseudo spray droplets according to claim 4, further comprising a dilution gas supply means for controlling the generation concentration of the pseudo spray droplets.

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