Process and apparatus for producing fine particles
First Claim
1. A process for producing fine particles, comprising the steps of:
- introducing a material for producing the fine particles into a thermal plasma flame to make a vapor-phase mixture; and
quenching the vapor-phase mixture to form the fine particles,wherein said step of introducing the material for producing the fine particles into the thermal plasma flame comprises the steps of;
dispersing or dissolving the material for producing the fine particles in a dispersion medium or solvent containing a combustible material to prepare a dispersion; and
making the dispersion into a form of droplets so as to introduce the dispersion in a droplet form into the thermal plasma flame, or dispersing the material for producing the fine particles with a carrier gas and a combustible material and introducing the dispersed material for producing the fine particles into the thermal plasma flame.
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Accused Products
Abstract
A fine particle producing process introduces a material for producing fine particles into a thermal plasma flame to make a vapor-phase mixture and quenches the vapor-phase mixture to form the fine particles. In the process, the material for producing the fine particles is dispersed or dissolved in a dispersion medium or solvent, preferably containing a combustible material to prepare a dispersion such as a slurry, a colloidal solution or a dissolution solution, the dispersion is made into a form of droplets, or the material for producing the fine particles is dispersed with a carrier gas and a combustible material and the dispersion in a droplet form or the dispersed material is introduced into the thermal plasma flame. In the fine particle producing process and apparatus, a gas of an amount sufficient to quench the vapor-phase mixture is supplied toward a tail of the thermal plasma flame. In the process and apparatus, primary fine particles are introduced into a cyclone to be subjected to cooling and classification and secondary fine particles having a particle size of 100 nm or less which are left upon removal of coarse particles are recovered.
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Citations
32 Claims
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1. A process for producing fine particles, comprising the steps of:
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introducing a material for producing the fine particles into a thermal plasma flame to make a vapor-phase mixture; and quenching the vapor-phase mixture to form the fine particles, wherein said step of introducing the material for producing the fine particles into the thermal plasma flame comprises the steps of; dispersing or dissolving the material for producing the fine particles in a dispersion medium or solvent containing a combustible material to prepare a dispersion; and making the dispersion into a form of droplets so as to introduce the dispersion in a droplet form into the thermal plasma flame, or dispersing the material for producing the fine particles with a carrier gas and a combustible material and introducing the dispersed material for producing the fine particles into the thermal plasma flame. - View Dependent Claims (7, 8, 9, 11, 12, 13, 15, 16, 17, 19, 20, 25)
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2. A process for producing fine particles, comprising the steps of:
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introducing a material for producing, the fine particles into a thermal plasma flame to make a vapor-phase mixture; and quenching the vapor-phase mixture to form the fine particles, wherein said step of introducing the material for producing the fine particles into the thermal plasma flame comprises the steps of; dissolving the material for producing the fine particles in a solvent to prepare a solution; and making the solution into a form of droplets so as to introduce the solution in a droplet form into the thermal plasma flame. - View Dependent Claims (10, 14, 22, 23)
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3. A process for producing fine particles, comprising the steps of:
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introducing a material for producing the fine particles into a thermal plasma flame to make a vapor-phase mixture; and supplying a gas of an amount sufficient to quench the vapor-phase mixture toward a tail of the thermal plasma flame to form the fine particles. - View Dependent Claims (6, 18, 21, 24)
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4. A process for producing fine particles, comprising the steps of:
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introducing primary fine particles formed by a predetermined treatment into at least one cyclone to subject the primary fine particles to cooling and classification based on a predetermined particle size; removing coarse particles having a particle size equal to or greater than the predetermined particle size by the classification; and recovering secondary fine particles having a particle size of 100 nm or less which are left upon removal of the coarse particles; wherein the treatment for forming the primary fine particles is a treatment in which a material for producing the fine particles is dispersed and then introduced into a thermal plasma flame so as to evaporate the material for producing the fine particles to make a vapor-phase mixture. - View Dependent Claims (5)
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26. A fine particle producing apparatus, comprising:
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a material supplying section that disperses a material for producing fine particles and supplies the dispersed material into a thermal plasma flame; a plasma torch connected to said material supplying section that generates said thermal plasma flame so as to evaporate the material for producing the fine particles to make a vapor-phase mixture; a cooling chamber connected to said plasma torch that provides a space necessary to quench said vapor-phase mixture; and a gas supplying section that supplies a as of an amount sufficient to quench the vapor-phase mixture toward a tail of said thermal plasma flame. - View Dependent Claims (29, 30, 31, 32)
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27. A fine particle producing apparatus, comprising:
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a material supplying section that disperses a material for producing fine particles and supplies the dispersed material into a thermal plasma flame; a plasma torch connected to said material supplying section that generates said thermal plasma flame so as to evaporate the material for producing the fine particles to make a vapor-phase mixture; a cooling chamber connected to said plasma torch that provides a space necessary to quench the vapor-phase mixture; and at least one cyclone as a classifying section into which primary fine particles formed by quenching the vapor-phase mixture are introduced. - View Dependent Claims (28)
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Specification