JPS62149331A - Device for generating particle having optional diameter - Google Patents

Abstract

PURPOSE:To obtain stabilized particles having optional diameter by vibrating a liq. contg. a particle forming substance by an ultrasonic oscillator, atomizing the liq., and sending dry air from a blast port to transport and dry the mists. CONSTITUTION:When ultrasonic oscillation is generated by oscillating a piezo- oscillator 12 provided on the bottom surface of a liq. vessel, mists are generated from the surface of the liq. contg. a particle forming substance. The mists are conveyed to a blowoff pipe 20 by the air sent from a blast port 16, and then further conveyed to an outlet 22 by the air from a blast port 18. Meanwhile, a solvent is volatilized from the particle, and dried fine particles are discharged from the outlet. In this process, an optional amt. of particles having optional diameter can be generated by changing the ratio in amt. of the gas sent from the blast port 16 to that sent from the blast port 18 and the concn. of the liq., and a device having extremely wide application in the coating material of a magnetic tape, etc., and a combustion catalyst can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to the field of fine particles, which has an extremely wide range of applications such as performance testing of clean rooms and microporous filters, coating materials for magnetic tapes and heat exchanger walls, and combustion catalysts. , relates to an apparatus for generating particles having an arbitrary particle size.

Conventional technology Fine particles and ultrafine particles (several tens of angstroms to 100 angstroms)
Various research and development efforts are underway regarding the generation and adjustment methods of micrometers (μm).
The New Materials volume contains papers titled ``Current status and future prospects of ultrafine particles'' and ``Prospects of fine ceramics.'' As described therein, in the conventional method for preparing fine particles, N2. A carrier gas such as Fle, Ar, II2, etc. is introduced and the gas is bubbled in the liquid to scatter the particles. However, with this method, the variation in particle size of the fine particles produced becomes extremely large, and furthermore, it is impossible to generate a stable number of particles. This has resulted in various drawbacks due to variations in particle size and number of particles.

Problems to be Solved by the Invention The object of the present invention is to provide an apparatus capable of stably generating particles having a desired particle size in the air for a long period of time.

Another object of the present invention is to provide an apparatus that can stably generate a large number of particles over a long period of time.

Means for Solving the Problems and Their Effects The above-mentioned objects of the present invention are to provide an ultrasonic transducer attached to a part of a liquid tank containing a liquid to be atomized and a substance capable of forming particles; a first air outlet provided at the top of the liquid tank for feeding gas, a blowing pipe extending upward from the top of the liquid tank, a second blowing port provided in the middle of the blowing pipe for sending gas, and a first air blowing port. ]'' and a valve mechanism that adjusts the amount of air blown from the second air outlet.

That is, the present invention utilizes an ultrasonic atomization device.

By changing the distribution of the amount of gas sent into the ultrasonic atomizer from the first air outlet and the amount of gas sent from the second air outlet towards the middle of the blowout pipe, It is possible to generate particles with a stable particle size and number; particles with a stable particle size. Furthermore, by changing the liquid concentration as necessary, it becomes possible to generate particles of arbitrary particle size and number.

The reason why we are able to obtain a stable particle size is that fine particles, polymer materials, chlorides, etc. are uniformly distributed or dissolved in the liquid at a certain concentration, so that they are not contained in the mist generated by ultrasonic waves. When the mist is carried into the air, only the solvent (solvent) evaporates, and the amount of fine particles, polymer materials, chlorides, etc. that aggregate in the air is uniform. Therefore, the particle size of the generated particles may also be -(,12).

Various gases other than air 3 can be used as the gas sent from the air outlet, but it is preferable that each air outlet 1' be a dry gas without moisture.

The present invention will be further described below with reference to embodiments of the accompanying drawings.

Embodiment FIG. 1 represents a preferred embodiment of the particle generator according to the invention, in which water is placed as a solvent in a liquid tank 10 as the liquid to be atomized, forming the particles to be atomized. Latex rings with a particle size of 0.091 μffl are mixed as a substance. A piezoelectric vibrator 12 is attached to the bottom of the liquid tank 10 as an ultrasonic vibrator, which vibrates in response to an AC signal from a drive circuit 14 to generate ultrasonic vibrations, vibrating the liquid and removing water and latex rings from the surface. It is designed so that it scatters in a mist. Liquid! A first air outlet 16 for feeding dry air is provided on the upper side wall of the i10, and a blowing pipe 2 extending upward is provided on the upper surface of the liquid tank lO.
0 is attached. Furthermore, the way of the blowout pipe 20 11
A second blower L118 is provided for sending dry air, and the blower pipe 20 is oriented horizontally from this position. The latex particles are elongated and agglomerated to a predetermined particle size are discharged from the outlet 22. The air vents 16,18 are supplied with dry air from the air pump 24 via valves 26,28, respectively. Valve 26.28 is control mechanism 3
0. For example, the flow rate is adjusted in response to a signal from an electric blower, E-type, or pneumatic automatic control device, and the amount of air supplied to the first and second ventilation ports is adjusted to change the distribution ratio. .

FIG. 2 is a principle diagram illustrating the fact that the particles generated by the apparatus shown in FIG. 1 have a uniform particle size. First, in state A, latex rings are uniformly dispersed in the aqueous solution. In state B, the mist generated from the water surface by ultrasonic vibration contains latex rings. C
In this state, only the solvent in the mist, that is, the water, is evaporated by the drying gas, and the latex rings are left in a coagulated state with a particle size of X. In state D, only the latex rings coagulated to particle size X remain, and the water completely evaporates and becomes invisible. In this way, particles of uniform particle size (@particle aggregate) are discharged from the outlet.

Experimental Example Figure 3 shows that particles were generated by the method of the present invention using a solution containing latex spheres with a particle size of 0.091 μII+ and water, and the number of generated particles (particle size of 0.091 μII+) was increased over 3 hours.
) is set at /l111 and its change over time is determined. 15 degrees of generated particles on the vertical axis is 1 cubic foot (0,0
The number per 283 cubic meters is expressed on a logarithmic scale. From this graph, it was found that the tonicity of the generated particles was almost uniform over a period of 3 hours, and extremely stable particle generation was obtained.

Figure 1 shows that particles are generated by the method of the present invention using an aqueous solution of NaCl dissolved in water instead of latex spheres, and the distribution of air volume is kept constant and the Na1l lfJ degree is 01.
% and 1% to determine the relationship between the number of generated particles and the particle size. This graph clearly shows the particle size peak, demonstrating that particles with a fairly uniform size can be obtained. It has also been found that by changing the concentration of NaCl, any desired particle size can be obtained.

As explained in Detailed Description I of the Effects of the Invention, the apparatus of the present invention can stably generate particles with any particle size in the air for a long time, and furthermore, the number of particles can be increased over a long period of time. Its effects are extremely remarkable, such as stabilization, allowing more accurate performance testing of clean rooms and microporous filters, and improving the performance of magnetic tapes and heat exchangers.

[Brief explanation of drawings]

Fig. 1 is a schematic sectional view of a particle generator according to the present invention, Fig. 2 is a schematic diagram showing the principle of the invention, Fig. 3 is a graph showing the change in the number of generated particles over time, and Fig. 4 is a graph showing the change in the number of generated particles over time. It is a graph obtained by determining the relationship between the number of generated particles and the particle size while changing the concentration. IO...Liquid jf112...Ultrasonic vibrator 14'...
・Drive circuit 16.18...Air outlet 20...Blowout pipe 22...Outlet 24...Pump 262
8...Valve patent applicant Shinryo Corporation Representative Patent attorney Tadashi Ninomiya Takaatsu 2 Figure 1 Crest 〔Do〕

Claims (1)

[Claims] 1. An ultrasonic vibrator attached to a part of a liquid tank containing a liquid to be atomized and a substance that can form particles, and a first ultrasonic vibrator installed at the top of the liquid tank to send gas. An air outlet, an air outlet extending upward from the top of the liquid tank, a second air outlet provided in the middle of the air outlet pipe to send gas, and an amount of air blown from the first air outlet and a second air outlet. 1. A generator for generating particles of any particle size, comprising: a valve mechanism that adjusts the amount of air blown from the valve mechanism. 2. The device according to claim 1, wherein the gas sent from each of the air outlets is dry air without moisture.