JPH01310735A - Method and apparatus for producing fine particles of liquid or melt - Google Patents

Abstract

PURPOSE:To obtain uniform and stable fine particles by spraying liquids or melts intermittently so that they run against the surface of liquids or melts of the same kind as the sprayed matters to be formed into aerosol. CONSTITUTION:Liquids L are sprayed downward from B nozzle 2 in a chamber 1. Liquids of the same kind L is stored at the bottom of the chamber 1. When the stream of spray SP is caused to run against the surface Ls of the liquids which is kept at a specified height F, particles S in the spray run against the surface Ls to be reduced to fine ones and are scattered upward above the liquid surface. Gases in the chamber 1 is caused to form an upward current CG by the succeeding, intermittent spray from the nozzle 2, whereby the fine particles less than 10mum are carried upward by the current CG, while the particles larger than 10mum having smaller buoyancy descend to be absorbed into the liquids L and are stored to be sprayed again.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method and apparatus for producing fine particles of liquid or melt.

[Prior Art] Conventionally, the method of producing liquid or molten particulates has been to impinge a spray of them on a hard plate, as seen in FIG. In this case, these fine particles vary in size, ranging from several microns to hundreds of microns, and cannot be called fine particles. In addition, in airless spray, the particle size distribution is relatively stable, but the particle size is within the range of 20 microns to 60 microns, and the cross-cut nozzle developed by Nordson Corporation (USA) Even when used, the particle size remained at around 12 microns. However, the operating conditions at that time were that the spray amount was relatively small, that is, 4.73 cc/min, the distance between the nozzle and the liquid surface was 300 mm, and the width of the bottom of the spray pattern was 7-250 mm. It is something. However, even in this case, especially when the viscosity is relatively high, a tail phenomenon tends to occur in the direction of both ends of the spray pattern, and large droplets of several hundred microns are generated in the turning portion. That is, it was difficult to obtain uniform fine particles overall.

[Problems to be Solved] As shown in the two series, the spray-to-hard plate collision method was effective in obtaining fine particles, even particles of around 1 micron were obtained. However, on the other hand, there were also particles of several tens of microns, which meant that the grains were not well-aligned and were unstable.

However, in recent years, with the demand for advanced technology, there has been an increasing need for always uniform and stable fine particles and for freely adjusting the density of the atomized particles containing them.

The motivation for the present invention was to try to meet the above needs.

[Means for solving the problem] Before that, we investigated the cause of irregular fine particles generated when using the conventional "double spray vs. hard plate collision method" (1.02). It is a hard board (105)
When the spray hits the hard plate, the particles in the spray collide with the hard plate and break into pieces, scattering into the air and becoming smaller particles. However, although it is good at first, as time passes, liquid or melt adheres to the surface of the hard plate (1,05), and the layer gradually becomes thicker as shown in Fig. 14. . Also, their surfaces may gradually dry out, ie the viscosity of the liquid or melt may increase and eventually solidify. As the hardness of the plate surfaces changes over time, the size of the particles that are crushed by colliding with those surfaces also changes over time. This is considered to be a major reason why the particle size of fine particles in the spray versus hard plate collision method becomes unstable over time.

However, the above phenomenon was an unavoidable problem as long as hard boards were used. Therefore, the inventors of the present invention focused their attention on hitting the spray stream directly onto the liquid or molten material stagnant below, without using a hard plate. The surface of the liquid or melt does not change over time as in the case of the hard plate described above. Therefore, the force that crushes the particles remains unchanged,
Fine particles of uniform size can always be stably obtained.

Since the surface of the liquid is much softer than the surface of the hardboard, it is likely that the crushing effect will be less and it will be difficult to obtain finer particles. However, the force at the time of collision is proportional to twice the speed at that time, and when the speed reaches a certain point, the kinetic energy becomes larger.
It has been experimentally confirmed that even on a soft liquid surface, sufficient crushing force is exerted and the required fine particles can be obtained. Since these fine particles are dispersed in a gaseous mass to form atomized particles, when these particles are used, it is required to freely adjust their density. It is obtained by intermittent spraying.

The gist of the present invention is to spray a liquid or melt intermittently and impinge on a surface of the same kind of liquid or melt, thereby crushing the atomized particles in the spray and making them finer. This is a method and apparatus for obtaining fine particles by scattering them into a gas on the surface of the liquid or melt, and at the same time adjusting the density of a vapor formed from the particles.

First, the method of the present invention will be explained. Liquids targeted by the present invention include solvents, emulsions, suspensions, and the like. Since the behavior of micronization of these particles differs depending on these types, each of these will be explained separately.

(1) In the case of a solvent This is the case with a solvent such as water or oil. The case in this section also forms the basis of the method of the present invention. Please refer to FIG. 1 first. 11. Spray (spray) the liquid (L) inside the Chan 8 (1) by directing the spray nozzle (2) downward. It is assumed that the same type of liquid (L) as above is retained at the bottom of the chamber (1), and the liquid level (Ls) is always maintained constant. The liquid level (
Apply the above-mentioned spray (SP) flow to the "Ls)" two (see Figure 2).

Particles (P) in the spray collide with the liquid surface (Ls),
It shatters into small pieces and scatters above the liquid surface (see Figure 3).

Among these more finely divided particles, for example, those of 10 microns or less are designated as p, and those larger than that are designated as P□.

The gas in the chamber (1) becomes an upward air current (Ca) by the subsequent spray from the nozzle No. 11 (see Figure 4), and particles with a relatively large surface area/weight, such as No. 11] Fine particles of 0 microns or less ( p) has a relatively large gas resistance, i.e., buoyancy force, so the updraft (CG) at a certain speed
It rises on board. On the other hand, particles with a surface area/weight smaller than those mentioned above, such as fine particles of 10 microns or more (
P□) has relatively small air resistance, that is, buoyancy force, so
It descends against the updraft (CG). That is, the size of the particles rising or falling is determined by a certain speed of the upward airflow, and the speed is determined by the amount of gas to be sprayed with two fluids or the amount of gas introduced into the chamber (1).

The thus separated and elevated gas containing fine particles (p), that is, the atomized gas, is led out of the chamber (1) and used for various purposes.

On the other hand, the fine particles (Pl) that have descended within the chamber (1) reach the same type of liquid (Ls), are absorbed by the same liquid (L), and are stored for a period of time. It is then returned to the tank in the above-mentioned spray circuit and sprayed repeatedly.

In addition, by keeping the liquid level (Ls) constant, the distance m (F) from the nozzle (2) is also constant, and the speed and crushing force at the time of collision are also constant, so that the particle size is uniform. Fine particles are obtained.

The v1 particles thus obtained are dispersed in the gas,
In other words, it becomes a vapor, but by performing the above-mentioned spray intermittently, it is diluted per unit time, and a vapor with a low overall density can be obtained. For example, as shown in Figure 5A, if you want to record the density of the atomized body as three-fifths of that in the case of continuous spraying, the spray will be applied in 50 cycles, that is, in a time of 20 m5 (milliseconds) per cycle. You can spray intermittently by setting the open position to 12 m and the spray close position to 815. Also, when you want to spray 50% of the time, set the spray open position to 4 m and the spray close position to 4 m, as shown in Figure 5B. It should be 16m5.

These intermittent times and cycles can be easily and arbitrarily set by using a pulse controller.

(2) In case of solution A solution is a liquid in which other substances are uniformly dissolved.

That is, other substances are dispersed in the form of molecules in a liquid solvent. The state of micronization due to the fragmentation of solution particles during these collisions is almost the same as in the case of the solvent in item 1 above, but the behavior from micronization to micronization is slightly different, so this will be explained below. .

Originally, a solution is a liquid solvent in which molecules of other substances are dispersed in a molecular state, and in general, the solvent often has a lower boiling point than the dispersoid. It is something.

The liquid surface collision of the spray particles of these solutions and the atomization by crushing are almost the same as in the case of the solvent described in item 1 above. The solvent in the particles (Pl) refined in this way has a relatively low boiling point, so as shown in Figure 6, the solvent substance in the particles (Pl) is gradually vaporized (px → P1' → pc) and is dispersed with a higher boiling point. The quality remains the same, but the mixing ratio is reversed. That is, the solvent is vaporized by heating operations, and depending on the degree of vaporization, fine particles of a solution having a desired mixing ratio can be obtained.

Furthermore, by completely vaporizing the solvent, it is possible to obtain fine particles consisting only of the dispersoid.

(3) In the case of emulsions An emulsion is a liquid in which a certain type of liquid or other types of liquids are dispersed in the form of particles. In other words, it can be considered that the molecular dispersion in the above 2nd term has been replaced by particulate dispersion, and therefore, in the behavior in collisional crushing, particles are made into fine particles through the same process as in the case of the solution. There is no harm in thinking that. Therefore, the compositional ratio of the emulsion of the fine particles can be varied within a certain range, and it is also possible to obtain fine particles consisting only of dispersoids.

(4)! ! In the case of a suspension, it is a liquid in which solid particles are dispersed, and examples thereof include a dispersion type coating agent or a powder slurry. In the case of an aqueous liquid, since it is slightly different from the above-mentioned thin liquid, the state of its collision and fracture will be explained. Please refer to FIG. Among the particles sprayed from the suspension (DS) nozzle (2), there are single solid particles (p), particles that are agglomerated solid particles (pp), and particles that are only liquid (Ill). , mixed particles of liquid and solid particles (
Pp) etc. exist. When the latter particles (Pp) collide with the liquid surface (DSs), among the particles that are crushed and scattered, as shown in Figure 8, there are also particles that are only solid (
p), or particles that are agglomerated multiple particles of these (pp), liquid-only particles (pQ), liquid-only fine particles (p(1)), particles that are a mixture of liquid and solid particles (Pp, ), etc. Among these, solid particles (p) and liquid-only particles (p (1)) have relatively large surface areas/weights as described in Section 1 above, so they are shown in Figure 9. As shown in the figure, the small particles rise on the updraft, and the smaller ones fall against the updraft and are separated by particle size.By further heating them, a vaporizable liquid is required. It is also possible to obtain only solid particles by removing the amount or all the liquid.

Although the explanation may be complicated, in the case of suspensions, solid particles tend to settle while they are moving through the pipes of the spray circuit, so care must be taken not to stop their flow. is essential.

In the following, we have discussed various forms of liquids, and next we will discuss the case of molten bodies. A molten body is something that melts and becomes liquid when heated. This covers a wide range of areas, including metals and ores, but for now the targets are thermoplastic resins, silicates, etc. When these are sprayed, the behavior of atomization is almost the same as in the case of the liquid in item 1 above, and in the case of a melt in which fine particles with a higher melting point are dispersed, These fine particles can be obtained in the same manner as in the case of the suspension in item (4) above.

There are two-fluid spray and airless spray methods for spraying the above-mentioned liquid or molten material, and since each of them has its own characteristics, these will be explained below.

Originally, a two-fluid spray jets out a considerable amount of gas (several hundred times the weight of the liquid) when it hits the spray.

After being ejected, the gas becomes a carrier air stream for separating fine particles as described above. The flow rate inevitably depends on the amount of ejection. However, that flow rate is not necessarily optimal for fractionation. In fact, it is rare to satisfy both conditions at the same time.

On the other hand, in airless spraying, no gas is used for spraying. Therefore, it is necessary to create a gas flow for separation. For example, if gas is introduced from the outside, the airflow conditions for separation can be satisfied separately from the spray. In addition, in the case of airless spraying, since air is not used, there is no need to dry out the liquid surface, which means there is no need to increase the concentration (viscosity) of the liquid surface being sprayed, and a constant state can always be maintained. be. These can be said to be the advantages of airless spray.

In addition, as a result of conducting various experiments on the basic model of the present invention, various data and additional matters for obtaining better results were obtained, which will be summarized and listed below.

1) The spray must be an airless spray, a knee/lower spray with auxiliary air, or a hot type thereof.

2) The spray must be a two-fluid spray or its variant.

3) The initial velocity of jetting from the nozzle hole is 25 m/sec.

Needless to say, by increasing the kinetic energy,
This is to further increase the crushing force at the time of collision.

4) Distance from the tip of nozzle (2) to the liquid level (Ls) (
F) shall be 75 mn or less. This is an important factor, especially when the flow rate from the nozzle is low.

5) The opening angle of the spray pattern must be 70 degrees or more. Particularly in the case of airless spraying, the purpose of this is to further reduce the size of the particles in the spray, that is, the size of the particles before impact fragmentation.

6) In order to prevent the large number of fine particles generated by the collision of the liquid surface of the spray from agglomerating, the fine particles are charged with static electricity, thereby causing them to repel and separate from each other. That is, corona discharge is performed within the chamber.

7) In the case of airless spraying, introducing gas into the chamber (1) to generate an updraft (CG).

8) In spraying an emulsion or suspension, heating the atomized body of liquid and solid particles generated by the collision to vaporize the liquid particles to reduce the number of liquid particles, or To produce a fume consisting only of solid fine particles.

9) Cooling the fumes produced by liquid or melt spray impingement, causing the particulates therein to rapidly solidify.

10) Spraying a suspension containing fine particles with a particle size of 1 micron or less as a dispersoid to obtain an atomized body of the fine particles.

11) The weight ratio of the dispersoid to the solvent in the suspension should be 1 or less.

12) For airless spraying of turbid liquids, the circuit of the device must be of a circulation type. The reason is that in intermittent spraying, in the case of a non-circulating type, the flow of the suspension stops when the spray is "interrupted", and the solid particles in the solution may settle, that is, the concentration may change upward or downward. If the suspension is circulated even during a "cut" and the suspension is kept flowing, such problems will not occur.

] 3) Similarly, in the case of suspensions, install in-pipe mixers at necessary locations along the circuit piping.

14) Similarly, in the case of suspension, an automatic concentration adjustment device must be installed in the tank.

Next, the basic structure of the apparatus of the present invention based on the above method will be explained. Please refer to FIG. Vertical chamber (
A spray gun (13) of an airless spray device (26) is provided on the outer wall of the side wall (11), approximately in the middle part, and an arm (13) of the airless spray device (26) is inserted into the vertical chamber (11) by penetrating the side wall from the gun. 14), a spray nozzle (12) is provided downward at the tip thereof, and the nozzle and the gun (13)
), and the gun is further wired to a timer or pulse controller (6o). The lower part of the vertical chamber (11) is a liquid storage chamber (15) in which liquid temporarily accumulates, and the lower end of the liquid storage chamber is connected to a return pipe (16),
The pipe is led to a tank (19) of an airless spray device (26) via an on-off valve (45). A pump (28), a filter (29), a regulator (47) are connected to the tank via conventional airless spray piping (27).
) etc. to the gun (13). In addition, in the case of two-fluid spray, as shown by the two imaginary lines in the same figure,
The piping (21) of the liquid supply device (20) is connected to the tank (
19) through the regulator (22), etc., and the pipe (24) of the spray gas supply device (23) is connected to the two-part gun (13) from the gas generator (CA) through the regulator (25), etc. Connected. In addition, these piping (2),
, 24, 27) are equipped with heaters (48, 4) as necessary.
9,54) are provided.

Note that by removing the tank (19), the liquid storage chamber (
15) can also be used as the tank. In that case, return piping (16) from the liquid storage chamber to the tank (19)
is connected to the inlet of the pump (28) via a check valve (59).

The liquid level in the liquid reservoir chamber (15) is a certain distance M(F) from the tip of the spray nozzle (12), for example, 75IIff.
Since it is desirable to maintain the liquid level (Ls) at a constant level, a level controller (3) is installed to automatically keep the liquid level (Ls) constant.
6) is provided. In the figure, a capacitive type is shown.

In addition, in the case of airless spray, mark it with a bell (
Slightly above Ls), the side wall of the vertical chamber (11)
Second, it is desirable to provide a gas introduction port (18) and an introduction gas supply device (30) connected thereto.

The two ends of the inside of the two-part chamber (11) serve as a fume outlet (17), and if necessary, an eliminator (53) for removing liquid particles is provided in front of the atomizer outlet (17). The two-part smoke outlet (17) is equipped with a gas exhaust pipe (50).
is connected to the pipe, and a heater (55) is installed on the pipe if necessary.

] The two-part chamber (11) body is preferably stretchable. In that case, the main body is divided into two lower parts and connected as a cylindrical sliding type (IIA, IIB), which has a spray nozzle (
12) to the upper part of the chamber (11), and when the eliminator (53) is installed as described above, it is used to adjust the height (H) to the bottom of the eliminator (53).
l) will be adjusted. The reason for this adjustment is that it is required during the separation of fine particles by means of a conveying air stream.

For suspensions, it is desirable to take the following measures in order to prevent solid particles from settling in the suspension.

That is, an automatic concentration adjustment device (75) is installed for the tank (19) in both airless spray and two-fluid spray devices.
) are added, and furthermore, on those spray circuit piping,
For example, in-pipe mixers (62) are provided at necessary locations. Further, in the case of an airless spray device, it is desirable that the spray circuit be of a circulating type (63).

[Operation] The operation of the device of the two-part invention will be explained. First, let us consider the case of a typical liquid solvent. Liquid (L
) is a conventional airless spray device! (26) or the spray nozzle (12) of the air spray device (20, 23)
Turn the timer or pulse controller (60
), etc., or by an intermittent electric signal or a pulsed electric signal, etc., to spray (sp) intermittently. i.e., except for their "cutoff" times, the liquid is sprayed,
The flow is the liquid (L) accumulated in the liquid storage chamber (15).
is struck onto the surface (Ls) of The above nozzle (12)
The distance (F) between and the liquid level (Ls) is 75+++
++ or less is desirable, and this can be easily done by adjusting the position of the level (Ls). Adjustment of the level (Ls) and maintenance of a constant position are performed by a level controller (36).

The sprayed (sp) and atomized liquid particles collide with the liquid surface, and they are crushed into small pieces and reflected and scattered into the gas above the liquid surface. These microparticulation steps were explained in detail in the section of the method of the present invention, so they will be omitted here.

Among the fine particles that have been atomized in this way, those with relatively small diameters, for example, those of 10 microns or less, ride on the upward airflow of convection that accompanies the spray flow in the airless spray in the vertical chamber (11). ``2 rise, 10
As stated in the above section of the present invention, particles larger than microns fall against the airflow. In this case, we assumed that it was 10 microns, but the selection of the size was
It is determined by the speed of the updraft. The above-mentioned updraft in convection is generated following the spray in airless spray, and its speed cannot be selected. Therefore, if an appropriate flow velocity is required, gas must be introduced from the outside through a separate, unique operation to generate an upward airflow having the required velocity. That is, the amount of gas required by adjusting the regulator (33) is introduced (G) into the chamber (11) by the introduced gas supply device (30). In this way, fine particles of a certain size generated in the chamber (11) are moved by an upward air flow (
CG), it is divided into two ascent or descent, but there is also a limit to the distance of ascent (H). It is a fine particle substance,
It varies depending on the particle size, etc., but experimental data has been obtained showing at least 200 strokes or more.

In this way, the vapor containing fine particles having the required small particle size is passed from the gas outlet (17) to the vapor exhaust pipe (50).
It passes through and is taken out of the chamber (11).

It is then used directly for various purposes.

The above has described the case of a liquid solvent, but next we will discuss the case of a liquid consisting of multiple types of liquids with different boiling points, that is, the case of a solution or an emulsion.

The process of atomization and sorting of liquid particles on the liquid surface is the same as in the case of the liquid solvent described above, and only relatively small-diameter particles rise. However, they contain a single type of fine particles or a mixture of multiple types of fine particles. When it is desired to remove a certain type of fine particle among these plural types of fine particles, if it has a lower boiling point than other types of fine particles, it may be heated to a temperature higher than its boiling point. The heating method can be applied to various spray devices (before the spray nozzle (12)).
20, 23, 26) or the introduced gas supply bag! (30)
The inside of the chamber (1), the liquid storage chamber (15), the smoke discharge pipe (50), etc. may be heated. In this way, a fume consisting only of fine particles with a high boiling point can be taken out from the gas exhaust pipe (50).

In addition, in the case of a suspension, fine particles of liquid and solid are generated after the liquid surface collides, so this can also be heated to a temperature higher than the boiling point of the liquid. A vapor containing only fine particles can be obtained.

Although heating has been mentioned as a method for removing low-boiling point liquids in the case of solutions, emulsions, and suspensions, an eliminator (53) as shown in FIG. 10 can also be used. However, it is desirable to use this in combination with the thin-cut heater mentioned above.

Finally, regarding the melt, if it is a melt of a single substance, a fine particle atomized body made of the melt can be obtained through almost the same process as in the case of the liquid solvent described above. In addition, if it is a physical mixture of multiple types of substances, it can be heated to a temperature above the boiling point of the substances, as in the case of double solutions, emulsions, and suspensions. , it is possible to obtain solid particles from which they have been removed.

[Example] In the above description, the chamber in this device is vertical, but it can also be horizontal. Please refer to FIG. In the horizontal type, the carrier gas is caused to flow laterally (CG), and during its lateral movement (Lw), relatively large particles are allowed to settle. In contrast to the above-mentioned vertical type, in the case of the horizontal type, the combination of wind power (CGi) and gravity (W) (F
), and between the drop (h), fine particles of various sizes coexist, making it difficult to clearly separate them. However, due to the construction of the building or the availability of equipment before and after the process, a horizontal type may be suitable.

Part 2. Although a timer is generally used for transmitting intermittent electrical signals, it is preferable to use a pulse controller in the present invention. This is because the intermittent electrical signal can be easily selected and set as a pulsed electrical signal, with intermittent cycles and their time distribution on the order of milliseconds and relatively steplessly.

Part 3. For suspensions, a circulation circuit (63) system is preferable in an airless spray device. The reason is l
I! This is to prevent sedimentation of the turbid liquid. That is, even when the spray is "cut off", circulation is maintained between the gun and the pump to maintain fluid flow within the circuit interconnections, thereby preventing solid particles in the suspension from settling.

Part 41 As explained in the method of the present invention, the distance between the spray nozzle (12) and the liquid level (Ls)
F) is preferably constant. Therefore, as mentioned above, the level controller (36) is necessary to keep the level constant. Although there are various types of level controllers, it is preferable to use a capacitive type in the device of the present invention. The reason is that there are no moving parts. Placing mechanically movable parts in an atmosphere where liquids are scattered causes the liquid to stick to the movable parts and inhibit their operation. On the other hand, capacitive devices have no moving parts and can operate normally even when exposed to liquid.

The configuration of the capacitive level controller 1-roller (36) will be briefly described. Please refer to FIG. 10 again. The capacitive sensor (37) consists of two electrodes. -More books
The other wire is connected to a high frequency oscillator (39) through an amplifier (40) to a comparator (42) in parallel with an indicator (41), and then through a relay (43). and is electrically connected to a valve drive motor (44) or an electromagnetically operated air operated valve (46). Next, its operation will be explained. First, a high frequency is oscillated from a high frequency oscillator (39),
11 (38) and reaches one electrode in the capacitive sensor (37). Then, the amount of electricity generated around the electrode depending on the distance between the electrode and the liquid level (Ls) is sensed by another electrode and amplified (40), and an indicator (41) The above signal is input to the comparator (42) in parallel with the above signal, and both signals are compared in the same comparator, and a positive or negative signal is transmitted, which is sent to the valve drive motor or electromagnet via the relay (43). Send it to the liquid storage chamber (15
) on the return pipe (''6) to the tank (19) or the liquid volume adjustment valve is activated. In this way, the level (Ls) in the liquid reservoir chamber (15) can be kept constant.

It is possible to do this. Further, the height of the above level can be arbitrarily adjusted by adjusting the indicator (41).

When performing airless spray in this 50-piece device, it is necessary to introduce gas into the chamber (11). The reason for this is that the chamber (11
) This is to separate large and small particles generated in the air by wind force. Its configuration will be explained. Please also refer to FIG. 10. A gas inlet (
18), connect the air volume indicator (35), filter (34), and air volume regulator (33) to the piping (31) in this order with the port facing the air blower (32), and connect the piping as necessary. A heater (52) is provided on top and the piping (31) is connected. Note that the gas inlet (18) is the capacitive sensor (37) described above.
The one placed below is the peter.

The operation of the cardiac body supply device (30) is the same as that of conventional general devices, so the explanation will be omitted.
It is important that the flow of the gas carrier flow (CG) introduced into the chamber rises as a parallel flow without causing turbulence.

61 When using a suspension or the like in this device to remove liquid particles from the generated particles, an eliminator (53) is used to help remove liquid particles by heating.
can also be provided in front of the splash outlet (17) at the top of the chamber (11).

Part 7. In the case of a suspension, the above 3. As mentioned in the section above, it is possible to use a circulation circuit type in airless spray equipment, but this is difficult in the case of two-fluid spray.
It is desirable to incorporate An in-pipe mixer is a mixer installed inside a pipe that can be connected to the above piping, and there are two types: static (equipped with a buffering plate) and dynamic (equipped with stirring blades). ) and so on.

Part 8. When the liquids sprayed into the chamber return to the tank, some of the liquids evaporate and naturally become more concentrated. It must be restored to its normal concentration in the tank. In this example, an automatic concentration adjustment device that automatically performs this is attached to the apparatus of the present invention. Please refer to FIG. 10 again. Tank (19
) is always operated with a stirrer (71) to keep the concentration in the tank uniform. The concentration is measured by a concentration detector (72)
is detected, and if it becomes larger than the set value, the concentration controller (73) issues an electric signal and the motor for the pump (78) on the pipe (77) from the solvent tank (76) is activated. (79) to supply the solvent (S) into the airless spray tank (19). Then, when it is diluted and reaches an appropriate concentration, the concentration detector (72)
However, this is detected and transmitted again, the motor (79) is stopped, and the supply of the solvent is stopped.

In this way, a constant concentration is always maintained. At the same time, when the liquid in the airless spray tank (19) is consumed and the liquid level drops, the lower limit (85) is reached.
is activated, and the piping (8) from the same type of liquid tank (81)
2) Motor (84) for upper pump (83) t=[moves;
The same liquid is supplied into the airless spray tank (19), and when the upper limit (86) is reached, the supply is stopped. In this way, the volume of liquid in the airless spray tank (19) can be automatically maintained within a predetermined range.

According to the method and apparatus of the present invention, there is no large variation in the fine particles generated by spraying a liquid or melt, and the density of the atomized material made of them can be controlled within a certain range. It is possible to obtain stable results while selecting the desired value.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the method of the present invention (hereinafter, unless otherwise specified, the present invention will not be referred to as the present invention). Figure 2 is an explanatory diagram of the state in which a spray of liquid or melt collides with a liquid surface. Figure 3 Figure 4 is an enlarged view of part B in Figure 2. Figures 5A and 5B are ejection time graphs for intermittent spraying. Figure 6 is a solution or emulsion. Vaporized components in particles such as suspension evaporate, and Figure 9 is an enlarged view of part C. Figure 9 is an enlarged view of part n Dn in the same figure as above. Figure 10 is a side cross section and configuration of the structure of the vertical device. Explanatory drawings Fig. 11 is a side cross-section of the structure of a horizontal device; Fig. 12 is an enlarged view of the II E 11 section on the top of the same drawing; Fig. 13 is an explanatory diagram of the conventional spray collision plate type; Fig. 14 is the collision plate surface in the same figure. Explanation diagram of the state in which liquid is layered on top Explanation of main symbols

Claims (31)

[Claims] (1) Spray the liquid (L) or melt (M) from the spray nozzle (2) intermittently at required intervals (
SP) and the same type of liquid or melt surface (Ls)
A method for producing fine particles of a liquid or molten material, characterized in that the particles in the spray are crushed and scattered by the reaction force thereof to produce fine particles, and a mist in which the particles are dispersed in a gas is obtained. (2) The method for producing fine liquid particles according to claim 1, wherein the liquid is a solvent, a solution, an emulsion, or a suspension. (3) The method for producing liquid fine particles according to claim 2, wherein the solid fine particles that are dispersoids in the suspension have a particle size of 1 micron or less. (4) The method for producing liquid fine particles according to claim 2 or 3, wherein the weight ratio of dispersoid to solvent in the suspension is 1 or less. (5) The method for producing fine particles of liquid or melt according to claim 1, wherein the spray is an airless spray, an airless spray with auxiliary air, or a hot type thereof. (6) The method for producing liquid particles or melt according to claim 1, wherein the spray is a two-fluid spray or a hot type thereof. (7) The method for producing fine particles of liquid or melt according to claim 1, 5, or 6, wherein the distance (F) between the nozzle and the liquid surface during spraying is 75 mm or less. (8) Opening angle of spray pattern in spray (
Claims 1 and 5 in which α) is 70 degrees or more.
A method for producing fine particles of a liquid or melt according to item 6 or 7. (9) The initial velocity from the nozzle during spraying is 25 m/
A method for producing fine particles of a liquid or melt according to claim 1, 5, 6, 7 or 8, wherein the speed is from 150 m/sec to 150 m/sec. (10) Heating the fume consisting of liquid and solid particles generated by the spray collision of a suspension, vaporizing the liquid particles to reduce them, or completely vaporizing them to reduce only solid particles. A method for producing fine particles of a liquid or melt according to claim 1, 3, or 4, characterized in that: (11) Claim 1 characterized in that a large number of fine particles generated by spray collision of liquid or melt are charged with static electricity and separated from each other to obtain single fine particles.
A method for producing fine particles of a liquid or melt as described in 1. (12) Spraying is performed in the chamber (1), gas (G) is introduced from the lower part of the chamber and above the liquid level to obtain a gas flow (CG), and the gas is heated or cooled as necessary. A method for producing fine particles of liquid or melt according to claim 1. (13) The liquid or melt according to claim 1, characterized in that a vapor containing fine particles of the liquid or melt is guided from the chamber (1) and the vapor is heated or cooled. How to generate fine particles. (14) A method for producing fine particles of a liquid or molten material according to claim 1, characterized in that the fine particles dispersed and suspended in a gas are carried on an air flow and guided to a desired location. (15) Generation of fine particles of a liquid or melt according to claim 1, characterized in that fine particles dispersed and suspended in a gas are placed in an air stream, and the size of the fine particles is separated according to the speed of the air stream. Method. (16) a. A vertical spray chamber (11) is provided, b. A spray gun (13) of a spray device is provided on the side wall of the vertical chamber (11), and c. The gun (13) is wired to a timer or pulse controller (60), and d. A spray nozzle (12) is inserted from the gun (13) into the vertical chamber (11) via an arm (14). is provided facing downward; e. The bottom of the vertical chamber (11) is a liquid storage chamber (15).
and the lower end of the chamber is connected to the tank (1) of the spray device (20).
9) and a pipe connection via a valve (45);
f. The upper end of the vertical chamber (11) is provided with a smoke outlet (17) and a smoke outlet pipe (50) connected thereto. generator. (17) The vertical chamber (11) is replaced by the horizontal chamber (91).
) The apparatus for producing fine particles of liquid or melt according to claim 16. (18) A vertical chamber (11) or a horizontal chamber (91) is divided into two parts (11A, 11B) in the middle thereof, and they are connected to each other in a cylindrical sliding manner and can be placed at any position. 18. The device for producing fine particles of liquid or melt according to claim 16 or 17, wherein the device is fixed. (19) The spray device is an airless spray device (26
) or an airless spray device with auxiliary air, or a hot type thereof, and furthermore, if necessary, they are a circulating circuit (63).
18. The apparatus for producing fine particles of liquid or melt according to item 6 or 17. (20) The spray device is a two-fluid spray device (20,
23) or their hot type Claim 1
18. The apparatus for producing fine particles of liquid or melt according to item 6 or 17. (21) The device for producing fine particles of liquid or melt according to claim 16 or 17, wherein the spray gun is provided inside a vertical or horizontal chamber. (22) The device for producing fine particles of liquid or melt according to claim 16 or 17, wherein the liquid reservoir chamber (15 or 95) is of a heating type. (23) The liquid or melt particle generation device according to claim 16 or 17, characterized in that a level controller (36) is provided in the liquid reservoir chamber (15 or 95). (24) A gas inlet (18 or 98) is provided at an intermediate portion between the liquid level (Ls) in the liquid storage chamber (15 or 95) and the spray nozzle (12 or 92) and on the side wall of the chamber; 18. The device for generating fine particles of a liquid or melt according to claim 16 or 17, wherein the inlet is connected to an inlet gas supply device (30) or a heating type inlet gas supply device through piping. (25) A patent claim characterized in that an eliminator (53 or 96) for removing liquid particles is provided in front of the smoke outlet (17 or 97) inside the vertical (11) or horizontal chamber (91). A device for producing fine particles of liquid or melt according to item 16 or 17. (26) Spray nozzle (12) or chamber (11)
18. The device for generating fine particles of liquid or melt according to claim 16 or 17, characterized in that electrodes (56, 57) for applying static electricity are provided in (91). (27) A device for generating fine particles of liquid or melt according to claim 16 or 17, characterized in that a heating or cooling device is provided on the vertical chamber (11) or the horizontal chamber (91). . (28) Claim 1, characterized in that a heating or cooling device is provided on the fume exhaust pipe (50, 94).
18. The apparatus for producing fine particles of liquid or melt according to item 6 or 17. (29) The liquid reservoir chamber (15 or 95) also serves as the tank (19) of the spray device, and the chamber has a check valve (59).
via the pump (28) of the airless spray device (26).
), or the flow rate regulating valve (
22) A device for generating fine particles of a liquid or melt according to claim 16 or 17, characterized in that the device is connected to the liquid or melt particle by piping. (30) Claim 16 or 2, characterized in that an in-pipe mixer (62) is provided on the liquid supply pipe (21 or 27) of the airless spray device (26) or the two-fluid spray device (20). 18. The apparatus for producing fine particles of liquid or melt according to item 17. (31) Automatic concentration adjustment device (75) in the tank (19)
18. The device for producing fine particles of liquid or melt according to claim 16 or 17, characterized in that an automatic liquid or melt replenishment device (80) is provided if necessary.