KR20210060749A - Core shell particle generator using spraying and drying method - Google Patents

Abstract

The present invention relates to an apparatus for generating aerosol particles using spray drying. The apparatus according to the present invention includes: a drying chamber through which liquid droplets and a conveying gas flow to dry sprayed liquid droplets; a pair of horizontal mount blocks installed at one sidewall of the drying chamber; an ultrasonic wave nozzle installed in the drying chamber concentrically with the horizontal mount blocks to spray the liquid droplets horizontally; an air flow path installed around the ultrasonic wave nozzle of the horizontal mount blocks to allow sheath flow through the conveying gas; a hot air blower installed at the top of the drying chamber to inject heated gas into the drying chamber; a silica gel diffusion dryer installed at the bottom of the drying chamber so that the vapor produced by the evaporation of the liquid droplets from the drying chamber may be adsorbed to provide particles free from water; and a particle collection filter installed at the rear end of the silica gel diffusion dryer to collect aerosol particles.

Description

Aerosol particle generation device using spray drying method {CORE SHELL PARTICLE GENERATOR USING SPRAYING AND DRYING METHOD}

The present invention relates to a particle generation apparatus using a spray drying method, and more particularly, a solution of a substance to be generated is sprayed in a droplet form using a droplet spraying device, and the solution is passed through a drying chamber that maintains a high temperature by a heat source. Silver is evaporated and the remaining particles are agglomerated to form a dried particle form, or by spraying a KCl or NaCl solution, it relates to an apparatus capable of generating particles through an ion crystallization process after spraying.

Equipment that can generate general particles is mainly an atomizer, a vibrating orifice aerosol generator (VOAG), an ink jet module, and an ultrasonic atomizer. Although the atomizer is a device that generates droplets under the pressure of air, it can produce particles of tens to hundreds of nanometers, but it is difficult to generate particles of several micrometers. VOAG is an equipment capable of generating monodisperse particles by using an orifice shape, but it is difficult to continuously generate particles due to the clogging of the nozzle outlet. The inkjet module is a device that generates monodisperse particles by adjusting the waveform and frequency of the internal vibrator, but it is difficult to generate a large amount of particles due to low droplet generation speed. The droplet ejection device has a uniform particle size distribution of several micrometers according to the vibration of the frequency of the internal vibrator and can generate a large amount of droplets. In order to generate the dried powder for the droplets generated by the ultrasonic nozzle, the particle generator generates an aqueous solution or slurry in the form of droplets using a nozzle, and the gas injected to dry it is heated through a heater and then dried. Dried particles can be made by feeding them into a chamber or passing them through a dryer that can absorb moisture well.

In the case of configuring the device in this way, when the conveying gas passes through the heater and reaches the drying chamber, additional heat cannot be supplied, so there is a problem that the temperature of the conveying gas gradually decreases. In addition, when the droplets are sprayed through the nozzle, there is a disadvantage that not only is lost from the wall of the drying chamber due to a wide spraying angle, but also the sprayed droplets are lost due to recirculation in the drying chamber. Therefore, efforts to more efficiently generate particles are being attempted steadily.

1. Korean Patent Registration No. 10-1970470 (2019.04.15) 2. Korean Patent Registration No. 10-1880349 (2017.12.06)

Stein, S. W., Gabrio, B. J., Oberreit, D., Hairston, P., Myrdal, P. B., & Beck, T. J. (2002). An evaluation of mass-weighted size distribution measurements with the model 3320 aerodynamic particle sizer. Aerosol Science and Technology, 36, 845-854. Lee, Haneol, Jeong, Young-Su, Choi, Kibong, & Shin, Weon Gyu (2017). The effect of sheath flow rate on the particle trajectory inside an optical cavity with direct flow configuration. Journal of Aerosol Science. 114, 146-156. Lee, Yao-Chuan, Jeng, Fu-Tien, & Chen, Chih-Chieh (2008). Technique for aerosol generation with controllable micrometer size distribution. Chemosphere. 73(5), 760-767.

An object of the present invention is to install a droplet spraying device for spraying droplets on the side of a drying chamber, and by installing a pair of air passages for sheath flow of the conveying gas so as to face each other. It is to provide an aerosol particle generation apparatus using a spray drying method in which the loss caused by the droplets colliding with the wall by focusing on the line can be reduced.

Another object of the present invention is to be conceived to solve the above problems, by placing the drying chamber in the oven and raising the temperature inside the drying chamber through heat transfer in the oven, so that the temperature inside the drying chamber can always be kept constant. It is to provide an aerosol particle generation device using a spray drying method.

In order to achieve the above object, the aerosol particle generation apparatus using the spray drying method according to the present invention,

A drying chamber in which the droplets and the conveying gas flow to dry the sprayed droplets; A pair of horizontal mount blocks installed on one side wall of the drying chamber; An ultrasonic nozzle installed concentrically with the horizontal mount block to spray droplets horizontally into the drying chamber; An air passage installed around the ultrasonic nozzle of the horizontal mount block to allow the sheath to flow through the conveying gas; A hot air fan installed at an upper end of the drying chamber in order to inject a gas whose temperature has risen into the drying chamber; A silica gel diffusion dryer installed at the bottom of the drying chamber to absorb the vapor generated by evaporation of droplets from the drying chamber to obtain particles from which moisture has been removed; And a particle collecting filter installed at a rear end of the silica gel diffusion dryer to collect aerosol particles.

The pair of horizontal mount blocks are installed opposite each other on one side wall of the drying chamber,

The ultrasonic nozzle is installed on any one of the pair of horizontal mount blocks to horizontally spray droplets inside the drying chamber,

The air flow path is characterized in that it is installed to face each other in the horizontal mount block so as to allow sheath flow through the conveying gas.

A hot air fan for injecting a gas having a temperature increased into the drying chamber is further installed at an upper end of the drying chamber, and a nitrogen gas tank and a gas flow controller are coupled to the hot air fan.

An oven is installed at a lower end of the drying chamber in which the horizontal mount block is installed so as to surround the outside of the drying chamber.

In order to control the amount of particles collected through the particle collection filter, a vacuum pump is installed connected to the particle collection filter.

According to the present invention, the method of controlling the temperature inside the drying chamber through an additional oven instead of controlling the temperature inside the drying chamber by injecting it into the drying chamber after heating the conveying gas through a heater according to the conventional method. There is an advantage of being able to maintain a uniform temperature inside of. In addition, a spray droplet injection device is installed above the particle generation device to inject the droplets downward into the drying chamber to obtain dried particles. Instead, a spray nozzle is installed horizontally on the side of the drying chamber, and a pair of additional air flow paths face each other. It is installed so that the conveying gas acts as a sheath flow and concentrates the sprayed droplets toward the center line of the drying chamber, thereby reducing the loss caused by the droplets colliding with the wall surface, thus generating more particles than before. There is an effect.

According to the present invention, there is an advantage of generating more particles of several micrometers than an atomizer, which is a device that generates droplets by pressure of air due to a sheath flow of a conveying gas.

1 is a schematic diagram of an aerosol particle generation apparatus using a spray drying method according to the present invention.
2 is an enlarged view illustrating an air flow path for sheath flow in an aerosol particle generation apparatus using a spray drying method according to the present invention.
3 is a diagram schematically showing the flow of droplets according to the presence or absence of the sheath flow of the present invention. (a) is a diagram showing the flow of droplets when the sheath flow according to the present invention is performed, and (b) is a diagram showing the flow of droplets when the sheath flow according to the present invention is not performed.
4 is a graph showing a comparison between the amount of particles generated by the atomizer and the particles generated according to the present invention.

Hereinafter, with reference to the accompanying drawings, a view showing an aerosol particle generation apparatus using the spray drying method according to the present invention.

The particle generation apparatus using the new spray drying method proposed by the present invention heats the conveying gas through a heater, injects it into the drying chamber, and places the drying chamber in the oven to increase the temperature inside the drying chamber through heat transfer in the oven. To be able to maintain it. The injected gas is heated through a heater and an oven, and the temperature inside the drying chamber is made uniform. In addition, since the ultrasonic nozzle is installed on the top of the drying chamber and sprayed downward, it is installed on the side of the drying chamber and sprays the droplets in a horizontal direction, so that the droplets can sufficiently receive heat transfer from the heater and oven. will be.

In addition, it has a structure in which the transport gas is injected through the ultrasonic nozzle and an additional air passage horizontally installed on the opposite side of the ultrasonic nozzle. At this time, the gas flowing in the additional air flow serves as a sheath flow and collects droplets sprayed from the nozzle to the center line of the drying chamber. The droplets sprayed by the ultrasonic nozzle are transferred in a controlled flow in the drying chamber, the moisture contained in the droplets is sufficiently evaporated, and the remaining particles come out of the drying module.

1 is a schematic diagram of an aerosol particle generation apparatus using a spray drying method according to the present invention, and FIG. 2 is an enlarged view showing an enlarged air flow path for sheath flow in an aerosol particle generation apparatus using the spray drying method according to the present invention.

1 and 2, the aerosol particle generation apparatus according to the present invention includes a drying chamber 4 in which droplets and a conveying gas flow in order to dry largely sprayed droplets, and the drying chamber 4 A pair of horizontal mount blocks (3) installed opposite each other on the side wall, and installed in any one of the pair of horizontal mount blocks (3) to horizontally spray droplets into the drying chamber (4) The ultrasonic nozzle (1), which is installed to face each other on each horizontal mount block (3), is installed at the bottom of the drying chamber (4) and the air flow path (11) to allow sheath flow through the conveying gas. A silica gel diffusion dryer 7 is installed at the rear end of the silica gel diffusion dryer 7 and a silica gel diffusion dryer 7 that absorbs the vapor generated by the evaporation of droplets from the drying chamber 4 to obtain moisture-removed particles, and collects aerosol particles. It includes a particle collecting filter (8).

A hot air fan 5 is installed at an upper end of the drying chamber 4 to serve to inject a gas having increased temperature into the drying chamber 4. Accordingly, a nitrogen gas tank 9 and a gas flow rate controller 10 are combined and installed in the hot air fan 5.

At the bottom of the drying chamber 4 in which the horizontal mount block 3 is installed, an oven 6 is installed to surround the outside of the drying chamber 4 to raise the temperature inside the drying chamber 4, and the It serves to maintain the temperature of the gas whose temperature is increased by the hot air fan (5).

The oven 6 is equipped with a control unit, and when the oven 6 is operated through the control unit, the internal temperature of the oven 6 is increased, and the air inside the oven 6 is increased through heat transfer. It is possible to raise or maintain the temperature of the drying chamber (4).

At this time, the internal temperature of the drying chamber 5 can be controlled by adjusting the temperature of the oven 6.

A nitrogen gas tank 9 and a gas flow controller 10 are connected to the air flow path 11 installed in the horizontal mounting block 3. Gas is generated from the nitrogen gas tank 9, and a conveying gas is injected into the air passage 11 through the gas flow controller 10 to allow sheath flow.

In this case, the sheath flow amount can be adjusted through the gas flow rate controller 10, and the sheath flow sprayed at the controlled flow rate can prevent the sprayed droplets from being lost from the wall.

The ultrasonic nozzle 1 may be sprayed by forming a solution into droplets using 80 kHz to 120 kHz ultrasonic waves.

The air passage 11 is installed to communicate around the outer wall of the ultrasonic nozzle 1, so that the conveying gas moves through the air passage 11. Therefore, the conveying gas flows along the outer wall of the ultrasonic nozzle 1 to make a sheath flow, and while being injected into the drying chamber 4, the droplets sprayed from the ultrasonic nozzle 1 are transferred to the center line of the drying chamber. You can focus on it.

That is, as shown in (a) of FIG. 3, droplets are sprayed from the ultrasonic nozzle 1 and at the same time, the transport gas injected from the air flow path 11 installed in the horizontal mount block 3 facing each other is liquid. Enemies can be collected toward the center line of the drying chamber (4). In this state, the droplets can move downward through the gas injected from the hot air fan 5.

If the sheath flow according to the present invention is not performed as shown in (b) of FIG. 3, the droplets sprayed from the ultrasonic nozzle 1 may be sprayed to the wall of the drying chamber 4 and be lost while colliding with the wall. There is.

The drying chamber 4 is preferably configured in a cylindrical shape, and the droplets sprayed from the ultrasonic nozzle 1 evaporate moisture by a transfer gas with an elevated temperature, and the remaining particles are aggregated to form the silica gel diffusion dryer. It will be transferred to (7).

The silica gel diffusion dryer 7 may adsorb vapor generated from the transferred dried droplets to obtain particles from which moisture has been removed. The particles may come out through the aerosol particle outlet (8).

In addition, particles exiting through the aerosol particle outlet 8 may be collected through the particle collection filter 12, and the amount collected at this time may be controlled by adjusting the flow rate of the vacuum pump 13.

<Example>

While the particles generated by the atomizer mainly have a diameter of 2 μm or less and it is difficult to make a larger size, droplets sprayed using the ultrasonic nozzle according to the present invention can generate particles while passing through the drying chamber and the silica gel diffusion dryer. The amount of particles having a size of 2 μm or more can be generated at a high concentration due to the action of the sheath flow. A graph of the results in this regard is shown in FIG. 4.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the following claims are also present. It belongs to the scope of rights of

1: ultrasonic nozzle
2: syringe pump
3: horizontal mount block
4: drying chamber
5: hot air
6: oven
7: silica gel diffusion dryer
8: aerosol particle outlet
9: nitrogen gas tank
10: gas flow controller
11: air flow
12: particle collection filter
13: vacuum pump

Claims (5)

In the aerosol particle generation device using the spray drying method,
A drying chamber in which the droplets and the conveying gas flow to dry the sprayed droplets;
A pair of horizontal mount blocks installed on one side wall of the drying chamber;
An ultrasonic nozzle installed concentrically with the horizontal mount block to spray droplets horizontally into the drying chamber;
An air passage installed around the ultrasonic nozzle of the horizontal mount block to allow the sheath to flow through the conveying gas;
A hot air fan installed at an upper end of the drying chamber in order to inject a gas whose temperature has risen into the drying chamber;
A silica gel diffusion dryer installed at the bottom of the drying chamber to absorb the vapor generated by evaporation of droplets from the drying chamber to obtain particles from which moisture has been removed; And
An aerosol particle generation apparatus using a spray drying method, characterized in that it comprises a particle collecting filter installed at a rear end of the silica gel diffusion dryer to collect aerosol particles. The method of claim 1,
The pair of horizontal mount blocks are installed opposite each other on one side wall of the drying chamber,
The ultrasonic nozzle is installed on any one of the pair of horizontal mount blocks to horizontally spray droplets inside the drying chamber,
The air flow path is an aerosol particle generation apparatus using a spray drying method, characterized in that the air flow path is installed to face each other in the horizontal mount block so as to allow sheath flow through the conveying gas. The method of claim 1,
An aerosol particle generation apparatus using a spray drying method, characterized in that a nitrogen gas tank and a gas flow rate controller are combined with the hot air fan. The method of claim 1,
An aerosol particle generation apparatus using a spray drying method, characterized in that an oven is installed at a lower end of the drying chamber in which the horizontal mount block is installed so as to surround the outside of the drying chamber. The method of claim 1,
An aerosol particle generation apparatus using a spray drying method, characterized in that a vacuum pump is installed connected to the particle collection filter in order to control the amount of particles collected through the particle collection filter.

Images