JPS5940493B2 - Method and device for mixing and homogenizing monodisperse fine particles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In the present invention, a solution that is solidified by drying is used, and fine particles generated by an atomizer or the like are classified as monodisperse fine particles by an appropriate method and then efficiently mixed with dry air. The present invention relates to a method and apparatus for mixing and homogenizing monodisperse fine particles, which are mixed and homogenized to solidify the monodisperse fine particles in the state of monodisperse fine particles.
In a monodisperse particle heating section connected to a particle generator, the supplied monodisperse particles are mixed and homogenized by a turbulent flow of dry air that passes through a filter made of porous material such as a glass filter. A dry air inlet and a filter made of a porous material such as a glass filter are provided on one side, a dry particle supply pipe is provided on the other side, and a portion near the filter between the filter and the dry particle delivery pipe is provided. Within the turbulence forming range of the filter,
The drying tube is characterized in that a particulate supply pipe led out from a particulate generator is opened to face the filter, and is heated by a heater such as a heater.

In general, monodisperse fine particles introduced into the heating section have two problems: if the drying speed is slow, collisions and agglomeration of the fine particles occur, resulting in the formation of polydisperse particles, and also the fact that the drying air and the monodisperse fine particles in the heating section Depending on the contact time, the properties of the monodisperse particles at the target concentration may be affected, so it is necessary to stir the monodisperse particles in the heating section, and to dehumidify and dry the monodisperse particles by mixing the monodisperse particles with dry air. must be done in a short period of time.

For example, when a thin cylindrical drying tube 1 is used as a heating section, if the flow rate of the fluid in the drying tube 1 is slow enough, adjacent parts of the fluid will not mix and dry. It moves regularly in layers parallel to the tube axis of tube 1,
When a fluid has a certain flow velocity, as shown in Fig. 1, friction occurs between the wall of the drying tube 1 and the fluid and the flow velocity decreases, and the flow velocity decreases at the center of the tube due to the frictional pressure. becomes faster, causing uneven flow velocity within the pipe.

If the opening of the particulate supply pipe 2 is arranged in the same direction as the flow of air, stirring and mixing by the flowing air will occur at the center of the pipe, as shown in FIG. Not only does it take time to stir and mix the entire mixture, but there is a risk that collisions and agglomeration of monodisperse particles may occur in areas where stirring and mixing are not uniform.

Therefore, as shown in FIG. 10, if a filter 3 made of a porous material such as a glass filter is installed upwind of the particulate supply pipe 2, the air introduced through the filter 3 will be , a turbulent flow is formed at the outlet of the filter 13, and the monodisperse fine particles supplied into the pipe from the fine particle supply pipe 2 are stirred and mixed with the air, and the particles are mixed with the pipe wall and the center. This eliminates the unevenness in flow velocity between the two parts and moves at a constant velocity, resulting in an ideal flow.

Furthermore, in order to further enhance these effects, as shown in FIG. 1, the opening of the particulate supply pipe 2 is arranged opposite to the air flow, and the filter 1 3 is arranged upwind of the opening. When air is introduced from the filter 13, a significant turbulent flow is formed by the air sprayed from the filter 13 and the flow of monodisperse fine particles fed in opposite to this, and the pressure between the pipe wall and the center part is increased. The difference in flow rate is eliminated, and the monodisperse fine particles and air are uniformly stirred and mixed.

For this reason, in the present invention, the particulate supply pipe is opened and set above the filter provided in the drying pipe within the turbulent flow forming range of the filter, and the drying air supplied through the filter Dehumidification and drying are performed by stirring and mixing the dispersed particles, increasing their efficiency.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of a method for mixing and homogenizing monodisperse fine particles and an apparatus therefor according to the present invention will be described below with reference to the drawings.

A dry particle delivery pipe 6 for delivering dry monodisperse fine particles is provided on the upper side of the drying pipe 5, which serves as a heating section in the form of a closed cylinder whose entire heating is controlled by a heater 4. A glass filter 18 is installed in the drying tube 5 above the dry air introduction tube 7, and a glass filter 18 is installed within the turbulent flow forming range of the filter 18 on the glass filter 18. , a particle supply pipe 9 into which monodisperse particles generated by a particle generator (not shown) such as an atomizer and classified into appropriate particle sizes are introduced is opened facing the glass filter 18. .

An example of a method for mixing and homogenizing monodispersed fine particles with dry air using this embodiment device is as follows.The fine particle supply pipe 9
3 is connected to a particle delivery pipe (not shown) in the particle generator that sends out the classified monodisperse particles generated by the particle generator, and the dry particle delivery pipe 6 is connected to the dried monodisperse particles. A cooling pipe (not shown) for cooling the particles is connected, and dehumidified dry air is introduced from the dry air introduction pipe 7.

When monodisperse fine particles are supplied from the fine particle supply tube 9 into the drying tube 5 connected in this way, the dry air introduced from the dry air introduction tube 7 is filtered through the glass filter 18 as described above. The monodisperse particles are sprayed at the outlet side, forming a turbulent flow, and are uniformly mixed while stirring the monodisperse particles supplied from the particle supply pipe 9.

During this time, the monodisperse fine particles are dehumidified and dried, solidified, and then sent from the dry particle delivery pipe 6 to the cooling pipe for the next step. In this example, the method and structure described above are shown. However, the present invention is not limited to the examples, and for example, the porous filter is not limited to a glass filter, but also a metal filter, and other filters that form turbulent flow and have a filtration effect. It is obvious that the material and structure do not matter as long as it is the same.

As described above, the method of the present invention mixes monodisperse fine particles supplied to the heating section with dry air by turbulent flow of the dry air through a filter made of a porous material such as a glass filter. Therefore, the monodisperse fine particles and dry air in the heating section are moved as a homogenized uniform air mixture flow, and dehumidification and drying are performed during this movement.
Even if this mixed gas flow is passed through the heating section for a short time, polydisperse particles are not created due to mutual collision or aggregation of monodisperse particles, and monodisperse particles can be obtained with good reproducibility.

Furthermore, in the apparatus of the present invention, by using a filter made of a porous material such as a glass filter, dust in the dry air is removed, filtered, and uniformly mixed with the monodisperse fine particles. Therefore, it is possible to obtain monodisperse fine particles with high purity without causing any change in their properties.
The filter has the advantage that it can be used repeatedly by washing.

Furthermore, since the particulate supply pipe in the device of the present invention is opened to face the filter 1 within the turbulent flow forming range of the filter 1, the dry air irradiated from the filter 1 and the dry air sent in opposite to the filter 1 are A significant turbulent flow is formed by the flow of the monodisperse fine particles, which has the effect of further uniform stirring and mixing of the monodisperse fine particles and the dry air.

As described above, the present invention has excellent effects particularly as a method and apparatus for mixing and homogenizing monodisperse fine particles.

[Brief explanation of the drawings] Figure 1 is an explanatory diagram of the fluid in the drying tube, and Figure 2 is an illustration of the fluid in the drying tube.
FIG. 1 is an embodiment diagram of the device of the present invention. 4...Heater, 5...Drying tube, 6.
...Dry particle delivery pipe, 7...Dry air introduction pipe, 8...Glass filter 9...
...Particle supply pipe.

Claims (1)

[Claims] 1. In a heating section for monodisperse particles connected to a particle generator, the supplied monodisperse particles are heated by a turbulent flow of dry air through a filter made of a porous material such as a glass filter. A method for mixing and homogenizing monodisperse fine particles, which is characterized by mixing and homogenizing monodisperse particles. 2 A dry air inlet and a filter made of a porous material such as a glass filter are provided on one side, a dry particle supply pipe is provided on the other side, and a dry air inlet is provided near the filter between the filter and the dry particle delivery pipe. , a unit comprising a drying tube in which a particulate supply pipe led out from a particulate generator is opened facing the filter within a turbulent flow forming range of the filter, and is heated by a heater such as a heater. Mixing and homogenizing device for dispersed fine particles.