JPH0657311B2 - Uniform particle size production method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing particles having a uniform particle size by dividing a liquid into droplets and then solidifying them.

[Prior art]

Conventionally, in a method for producing a particulate matter such as a carrier for immobilized biocatalyst, a gelled food and a polymer, as a device for dividing a liquid into droplets, a granulated liquid is discharged from a nozzle or a hole of a porous plate. A device that drops droplets that have been spheroidized and divided by the surface tension of the liquid, or a device that imparts vibrations of a certain frequency to the liquid to be granulated and that is ejected from the nozzles or holes in the perforated plate and that propagates the liquid flow into droplets. Alternatively, a device or the like that uses a two-fluid nozzle to eject a liquid to be granulated together with a dividing gas and divide the liquid into droplets is used. The above-mentioned divided droplets are spheroidized by the surface tension while falling and fall into the solidifying liquid, and are solidified by the solidifying liquid to produce particles, but the droplets are dispersed by the impact of collision with the surface of the solidifying liquid. And flattened, which made it difficult to produce particles having a uniform particle size. In view of the above circumstances, the present applicant has previously proposed that a method and an apparatus for always producing particles with a uniform particle size with good yield, by contacting the solidification liquid while the droplets of the liquid to be granulated fall A method for producing, a device for ejecting a solidifying liquid as a continuous liquid flow from a discharge nozzle to bring them into contact with each other, and a device for spraying the solidifying liquid from a spray nozzle to bring them into contact with each other are provided in order to carry out the method. (Japanese Patent Application No. 1-35022) [Problems to be Solved by the Invention] In the above-mentioned particle manufacturing apparatus applied earlier, a large amount of particles having a uniform particle size are manufactured with a high yield as compared with the conventional apparatus. It became possible, but there were the following problems.

In a device in which droplets of a liquid to be granulated are brought into contact with a liquid column-shaped solidified liquid stream, it is difficult to bring droplets from a large number of holes at the same time to produce a large number of particles because the diameter of the liquid stream is small Also, a large amount of liquid is required. When the liquid film is thin in a device that makes contact with a liquid film-like liquid flow, the liquid droplets pass through the film, so the contact time is short and the surface of the liquid droplets does not solidify sufficiently and falls. Since there is a risk that the particles may be flattened by the impact with, and the liquid film needs to be thickened in order to drop the liquid droplets with the liquid flow, an extremely large amount of liquid is required. In an apparatus for contacting the solidified liquid sprayed by spraying, the surface of the liquid droplet may not be solidified sufficiently and may drop, or particles may be blown off by the spraying. The present invention provides a method for producing particles, which is produced by improving the above apparatus to produce particles having a more uniform particle diameter with a high yield.

[Means for Solving the Problems]

The gist of the present invention is to divide a granulation liquid into droplets, and in a particle manufacturing method of granulating by dropping in a solidification liquid, a solidification liquid is a continuous liquid below a drop hole of the granulation liquid of a particle manufacturing apparatus. A uniform grain characterized by being provided with an inclined chute that flows down as a flow, and controlling the flow rate of the solidified liquid that flows down the chute to be approximately the same as the drop rate of the droplets of the liquid to be granulated. It is a method for producing fine particles. The liquid to be granulated means a liquid substance, and includes a liquid containing a solid such as a slurry.

[Work]

Droplet B divided by the droplet generation unit and having an arbitrary uniform particle size
Falls on the surface of the solidified liquid D flowing down on the chute 7 provided below the drop hole 5. Since the chute 7 is provided so as to be inclined, the droplet B collides obliquely with the surface of the solidification liquid D, and since the droplet B flows down along with the liquid flow, the impact of the collision is small, and the flow velocity of the solidification liquid D is particularly high. The impact is further reduced by controlling according to the drop velocity. The droplets B are accompanied by the solidifying liquid D, flow down, are introduced into the particle receiving tank 6, and are solidified to the inside in the solidifying liquid D that remains, and the particles C are manufactured. Incidentally, it is also possible to produce the encapsulated particles by separating the particles C within a time when the inside of the droplet B is not solidified, or by using the granulated liquid A and the solidification liquid D which solidify only the surface of the droplet B. Is. By the above, particles having a uniform particle size are manufactured.

〔Example〕

Detailed description will be given below with reference to the drawings showing a small-scale particle manufacturing apparatus applied to an embodiment of the present invention. Figure 1 is a system diagram, 2
The figure is a side view of the main part chute, and FIG. 3 is a view taken along line II-II of FIG. Reference numeral 1 is a stock solution tank for storing a stock solution A which is a liquid to be granulated, and a pressure gas introduction hole for pushing the stock solution A to the upper part,
It is an airtight tank with a discharge hole for the stock solution A in the lower part. Two
Is a shaker that vibrates the undiluted solution A at a constant frequency to produce uniformly divided droplets B. The undiluted solution A is introduced at the side, the undiluted solution A is dropped at the lower end, and vibrated at the upper part. It has a child 3. Reference numeral 4 is an oscillator for transmitting a constant frequency signal to the vibrator 3. 6 is a particle receiving tank in which the solidified liquid D is stored and solidifies the dropped liquid droplets B. A wire net basket 10 for receiving and taking out the particles C and an outlet hole for circulating the solidified liquid D in the lower side wall are provided. It has. Reference numeral 7 denotes a chute for causing the solidification liquid D circulated by the circulation pump 8 through the circulation passage 11 to flow down so as to come into contact with the droplet B. The chute 7 is provided so as to be inclined, and its inclination angle is set so as to be adjusted to the flow rate of the solidified liquid D obtained mainly based on the drop velocity of the droplet. As the chute 7 becomes longer, the solidified liquid D layer becomes shallower toward the end, and the droplet B may directly contact the surface of the chute 7 and be deformed. Therefore, the distance of the chute 7 is shortened or the inclination angle is lowered. It is appropriately adjusted such that it becomes smaller as it goes to, or it becomes narrower as it goes downward. Further, by widening the flow width of the chute 7, a large number of droplets B can be dropped at the same time to produce a large amount of particles at the same time.
The flow rate of the solidified liquid D is displayed by the flow meter 9 and adjusted by the flow rate adjusting valve 12, but the adjustment of the normal flow rate adjusting valve 12 is automatically controlled by an instruction of the flow meter 9 via a controller (not shown). Reference numeral 13 is a clamp for adjusting and fixing the inclination angle and height of the chute 7. The clamp 13 has two cylindrical members 13a, 13a each having an engaging portion facing one end surface of the clamp 13.
A hole 16 into which the frame 14 is loosely inserted is formed in one member 13a in the diametrical direction, and the bottom of the chute is fixed to the peripheral portion of the other member 13b. Shoot 7
To adjust the tilt angle and height of the
The height of the chute is adjusted by tightening and fixing it with screws 15a at a predetermined height position and adjusting the meshing position of the two members 13a and 13b and tightening and fixing it with screws 15b. The tilt angle of 7 is adjusted. Note that the particle manufacturing apparatus is not limited to the above-described configuration, and various known apparatuses can be used particularly in the divided liquid droplet B generation unit, the inclination angle and height adjustment unit of the chute 7, and the like. A method of one embodiment for producing particles having a uniform particle size by the apparatus having the above-mentioned structure will be described in detail below. A pressure gas is supplied into the stock solution tank 1 to extrude the stock solution A of the liquid to be granulated and introduce it into the vibrator 2. The introduced undiluted solution A is vibrated by the oscillator 3 vibrating based on the frequency with a constant frequency signal from the oscillator 4, and is discharged from the drop hole 5. While being discharged, the discharged liquid flow is divided by vibration propagating in the liquid flow and dropped as droplets B onto the surface of the solidified liquid D flowing down on the chute 7. Since the particle diameter of the droplet B is determined by the hole diameter of the drop hole, the discharge flow velocity, the vibration frequency, etc., it is possible to generate a droplet having an arbitrary uniform particle diameter by appropriately setting them.
The liquid droplet B that has dropped onto the surface of the solidified liquid D flows down along with the solidified liquid D whose flow rate is controlled in accordance with the liquid drop speed, and is introduced into the particle receiving tank 6 and is retained inside the solidified liquid D that remains. To be solidified to produce particles C. Further, in the above, the droplet B
It is also possible to produce encapsulated particles without solidifying to the inside. After the particles are produced, the wire mesh basket 10 is lifted to take out the particles C and separate them from the solidifying liquid D.

〔The invention's effect〕

 The particle manufacturing apparatus of the present invention has the following effects.

B) Since the droplets collide obliquely with the solidified liquid and flow down along with the liquid flow, the impact of collision is small, and the shape of the droplets is difficult to change, so that particles with a substantially uniform particle size are produced. In particular, since the flow rate of the solidified liquid is controlled according to the drop velocity of the liquid droplet, the impact can be further reduced. Therefore, it is possible to improve the ability to produce particles having a uniform particle size as compared with the conventional apparatus.

(B) By widening the distribution width of the chute, it is possible to simultaneously drop liquid droplets from a large number of holes and simultaneously produce a large amount of particles having a uniform particle size.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention, FIG. 2 is a side view of a main chute, and FIG. 3 is a II-II view of FIG. 1; stock solution tank, 2; vibrator, 3; vibrator, 4; oscillator,
5: Falling hole, 6; Particle receiving tank, 7; Chute, 8; Circulation pump, 9; Flow meter, 10; Wire gauze basket, 11; Circulation flow path, 12; Flow control valve, 13; Clamp; 14; Frame, 15a , 15b;
Screw.

Claims (1)

[Claims] 1. A method for producing particles, in which a liquid to be granulated is divided into droplets and dropped into a solidifying liquid for granulation, wherein the solidifying liquid is a continuous liquid flow below a drop hole of the liquid to be granulated in a particle producing apparatus. A uniform particle size characterized by being provided with an inclined chute that flows down as a granule, and controlling the flow rate of the solidified liquid that flows down the chute to be approximately the same as the drop speed of the liquid to be granulated. Particle manufacturing method.