JPH029342B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention connects the space inside the casing with a raw material supply path and a hot air supply path at the top, a cold air supply path between the top and bottom, and an exhaust and spherical material recovery path at the bottom. The thermoplastic powder from the raw material supply path is
Melts or softens with hot air, becomes spherical due to surface tension,
This invention relates to an improvement of a device configured to solidify the spherical shape with cold air.

The above-mentioned apparatus is generally used to process extremely fine powder and granules, such as spheroidizing toner for copying to improve resolution. It has the disadvantage that it is impossible or extremely difficult to maintain good operation for a long time due to the adhesion and accumulation on the inner surface.

More specifically, in conventional equipment, the part of the casing peripheral wall facing the casing internal space above the connection position of the cold air supply path becomes hot due to the supplied hot air, and powder particles floating within the casing become hot. The body tends to come into contact with the high-temperature peripheral wall part due to the action of hot air, and therefore, there is a drawback that the powder or granules, while still in a molten or softened state, stick to the high-temperature peripheral wall part and the molten or softened material that adheres thereto.

An object of the first invention is to effectively prevent powder from adhering to the peripheral wall of the casing.

The object of the second invention is to more effectively prevent the adhesion of powder and granules to the peripheral wall of the casing, and also to prevent the adhesion of the powder and granules to the nozzle that supplies the powder and granules into the casing and the surrounding area thereof. The point is to enable effective prevention.

It is an object of the third invention to effectively prevent the adhesion of particulate matter to the peripheral wall of the casing, the nozzle, and the surrounding area, and also to effectively prevent the adhesion of suspended particulate matter to each other. It is in.

The characteristic configuration of the apparatus according to the first invention is that the cold air is formed between the upper and lower sides of the casing, in which the raw material supply channel and the hot air supply channel are connected to the upper part, and the exhaust and spherical material recovery channel is connected to the lower part of the peripheral wall of the casing. A cooling jacket is attached to a portion facing the inner space of the casing above the connection position of the supply path, and an air supply path is provided to form a gas curtain flowing downward along the inner surface of the peripheral wall portion. The functions and effects are as follows.

In other words, it is possible to prevent powder particles floating in a molten or softened state from coming into contact with the peripheral wall by the shielding effect of the gas curtain, and by keeping the temperature of the peripheral wall low by the cooling jacket. Even if the granular material moves or migrates to the peripheral wall portion, the contact surface of the granular material can be cooled and solidified at the peripheral wall portion, and adhesion of the granular material to the peripheral wall portion can be prevented.

As a result, it has become possible to continuously and reliably form thermoplastic powder particles into good spherical shapes over a long period of time without any problems caused by particles adhering to the casing peripheral wall, improving processing performance. I was able to sufficiently improve my abilities.

In addition to the features of the first invention described above, the characteristic structure of the apparatus according to the second invention is that a cooling jacket is attached to the nozzle forming the raw material supply path, and a hot air outlet is provided from the hot air supply path to the casing inner space. The porous body forming the casing is formed into a substantially truncated conical shape, and the center thereof is provided so as to substantially coincide with the vertical center of the casing, and the nozzle is provided so that its blowing direction is directed downward and substantially coincides with the center of the porous body and the casing. The outer peripheral surface of the nozzle tip is
The reason for this is that it is formed into a tapered surface whose diameter becomes smaller toward the distal end, and its effects are as follows.

In other words, like the first invention, the gas curtain and the cooling jacket can prevent the powder from adhering to the peripheral wall, and the powder and the granules blown out from the nozzle can be
Due to the almost truncated cone-shaped porous body surrounding the nozzle,
The action of the hot air blown from the entire circumference of the nozzle toward the center of the casing allows it to be lowered at the center of the casing, which also suppresses contact between the powder and granules and the surrounding wall, and as a whole, the surrounding wall It is now possible to more effectively prevent troubles caused by particles adhering to parts.

Moreover, by making the tip of the nozzle protrude inward from the porous body and by forming the outer peripheral surface of the nozzle tip into a tapered surface along which the hot air flows smoothly, the powder and granules can The vortex flow effectively prevents adhesion to the nozzle tip and the upper part of the porous body, and as a result, equipment troubles due to adhesion of powder and granules can be more reliably prevented.

The characteristic configuration of the device according to the third aspect of the present invention is that, in addition to the characteristic configuration in the second aspect of the present invention described above, a porous body is provided to form a cold air outlet from the cold air supply path to the casing inner space. is as follows.

In other words, not only can the functions and effects of the second invention described above be achieved, but also cold air can be blown out in a soft state due to the action of the porous body, and harmful eddy currents can be prevented from being generated, for example when cold air is blown out strongly. It is possible to avoid the inconvenient situation where the falling powder and granules are lifted up by the blowing of the cold air caused by this, and the powder and granules stick to each other, and as a result, the falling powder and granules are cooled and solidified by the cold air. It can be smoothly brought to the center of the casing while maintaining its spherical shape and collected smoothly.

Therefore, as a whole, it has become possible to sufficiently prevent adhesion between the powder and granules and the adhesion of the granules to each other, and to perform a good spheronization process reliably and efficiently.

Next, an example will be shown with reference to FIG.

The casing 1 has a substantially circular cross-sectional shape, is vertically elongated, has a lower part converging, and is erected so that the vertical center P is substantially vertical.

A nozzle 2 forming a raw material supply path 2a is provided in the upper part of the casing 1 so that its blowing direction is directed downward and substantially coincides with the casing center P, and the thermoplastic powder from the raw material supply hopper 3a is transferred to the blower 3b and A raw material supply device 3 configured to be pneumatically transported by an ejector 3c is connected to the nozzle 2.

In addition, 17 in the figure is a preheater provided as necessary.

A porous body 4 having a substantially truncated conical shape is provided in the upper part of the casing 1 so that its center P substantially coincides with the center P of the casing 1 and the nozzle 2, thereby forming a hot air supply path 5 and a hot air outlet 4a. , blower 6
A and an electric heater 6b are configured to blow hot air from a hot air generator 6 comprising a hot air generator 6 and an electric heater 6b from the entire opening of the nozzle 2 in the casing 1 toward the casing center P and diagonally downward.
The structure is such that the powder from the nozzle 2 is melted or softened by hot air and then sphericalized by surface tension.

A cooling jacket 2b is attached to the nozzle 2, the tip of the nozzle 2 is made to protrude into the inside of the porous body 4, and the outer peripheral surface 2c of the tip of the nozzle 2 is formed into a tapered surface whose diameter becomes smaller toward the tip. The porous body 4 is configured to prevent powder from adhering to the tip end portion of the porous body 4 and the top of the porous body 4.

A cold air supply path 7 is provided between the top and bottom of the casing 1 to uniformly blow cold air from all around the casing 1, and the powder and granules falling into a spherical shape are cooled and solidified by the cold air from the blower 8. A ring-shaped porous body 9 forming a cold air outlet 9a from the passage 7 to the inner space of the casing 1 is provided to prevent falling powder and granules from being blown up and to prevent turbulence caused by harmful vortices. The structure is such that it falls while being pushed toward the center P of the casing without causing any occurrence.

At the bottom of the casing 1, there is an exhaust and spherical object recovery channel 10.
are connected to the cyclone 11a for collecting spherical objects, the bag filter 11b, and the exhaust blower 1.
A recovery device 11 consisting of 1c is connected to the recovery path 10, and an intake path 12 is provided for sucking outside air for cooling into the recovery path 10, so that the spherical powder is sufficiently solidified and recovered. .

A cooling jacket 13 is attached to a portion 1a of the peripheral wall of the casing 1 that faces the inner space of the casing 1 above the connection position of the cold air supply path 7, and cool air from a blower 14 is provided along the inner surface of the peripheral wall portion 1a. An air supply path 15 is provided for forming a gas curtain by causing the powder to flow downward, and
It is configured to prevent adhesion to a. Further, a cooling jacket 16 is attached to the lower narrowed portion 1b of the casing 1 so as to prevent powder particles from adhering to the lower narrowed portion 1b. The cooling jackets 2b, 13, and 16 are configured to be supplied with cold water and cold air by pumps and blowers (not shown).

Next, another example will be described.

The gas supplied from the hot air supply path 5, the air supply path 15, the cold air supply path 7, the intake path 12, etc. can be changed to air, inert gas, or other suitable gas, such as resin, dye,
It is selected depending on the properties of the thermoplastic powder containing pigments, other organic substances, low melting point inorganic substances, etc.

To form the porous body 9 for the cold air supply path 7,
As shown in FIG. 2, all the cold air outlets 9a are formed to blow out cold air toward the casing center P and obliquely downward, or as shown in FIG. If at least some of the cold air outlets 9a and 9b blow out cold air downward, for example, only the cold air outlet 9b blows out the cold air downward, the powder and granular material can be discharged even more smoothly.

When forming the exhaust and spherical material recovery passage 10 and the intake passage 12, they may be formed into tube shapes as shown in FIG. 2 to facilitate gas transport of the powder and granules. Collection path 10 to prevent bodies from adhering to the
It is preferable that the straight pipe portion B forming the inlet side of the pipe is sufficiently long.

In the first invention, the configuration for forming the raw material supply path 2a, the shape and presence or absence of the porous bodies 4 and 9 for the hot air supply path 5 and the cold air supply path 7, the installation range and presence or absence of the cooling jacket 16 below the cold air supply path 7, Intake path 1
The presence or absence of 2 is irrelevant.

In the second invention, the shape and presence or absence of the porous body 9 relative to the cold air supply path 7, the installation range and presence of the cooling jacket 16 below the cold air supply path 7, the presence or absence of the intake path 12, etc. do not matter.

In the third aspect of the present invention, the installation range and presence or absence of the cooling jacket 16 below the cold air supply path 7, the presence or absence of the air intake path 12, etc. do not matter.

Dimensions and shape of casing 1, raw material supply device 3,
The configurations of the hot air supply device 6 and the recovery device 11, and others can be changed as appropriate.

[Brief explanation of drawings]

FIG. 1 is a schematic longitudinal sectional view showing an embodiment of the present invention;
FIGS. 2 and 3 are schematic cross-sectional views of main parts showing different embodiments of the present invention. 1... Casing, 1a... Peripheral wall portion, 2...
Nozzle, 2a... Raw material supply path, 2b... Cooling jacket, 2c... Outer peripheral surface of tip, 4... Porous body,
4a...Hot air outlet, 5...Hot air supply path, 7...
Cold air supply path, 9... Porous body, 9a, 9b... Cold air outlet, 10... Recovery path, 13... Cooling jacket, 15... Air supply path, P, P'... Center.

Claims (1)

[Claims] 1. For the space inside the casing 1, a raw material supply path 2a and a hot air supply path 5 are provided at the top, a cold air supply path 7 is provided between the upper and lower portions, and an exhaust and spherical material recovery path 10 is provided at the bottom.
is a spheronizing device for thermoplastic powder and granular material, in which a part of the peripheral wall of the casing 1 is connected to a part of the casing 1 above a connection position of the cold air supply path 7.
A thermoplastic granular material having a cooling jacket 13 attached to a portion 1a facing the inner space and an air supply path 15 for forming a gas curtain flowing downward along the inner surface of the peripheral wall portion 1a. Spheronizing device for use. 2. For the space inside the casing 1, a raw material supply path 2a and a hot air supply path 5 are connected to the upper part, a cold air supply path 7 is connected to the upper and lower middle, and an exhaust and spherical object recovery path 10 is connected to the lower part.
is a spheronizing device for thermoplastic powder and granular material, in which a part of the peripheral wall of the casing 1 is connected to a part of the casing 1 above a connection position of the cold air supply path 7.
A cooling jacket 13 is attached to the portion 1a facing the inner space, and an air supply path 15 for forming a gas curtain flowing downward along the inner surface of the peripheral wall portion 1a is provided, and the raw material supply path 2a is A cooling jacket 2b is attached to the nozzle 2 to be formed, and the porous body 4 forming the hot air outlet 4a from the hot air supply path 5 to the inner space of the casing 1 is formed into a substantially truncated conical shape, with its center P The nozzle 2 is arranged so that its blowing direction is downward, which almost coincides with the center P of the casing 1, and the tip thereof is located inside the porous body 4. A spheronizing device for thermoplastic powder or granular material, wherein the outer circumferential surface 2c of the tip of the nozzle 2 is formed into a tapered surface whose diameter becomes smaller toward the tip. 3 For the space inside the casing 1, a raw material supply path 2a and a hot air supply path 5 are connected to the upper part, a cold air supply path 7 is connected to the upper and lower middle, and an exhaust and spherical object recovery path 10 is connected to the lower part.
is a spheronizing device for thermoplastic powder and granular material, in which a part of the peripheral wall of the casing 1 is connected to a part of the casing 1 above a connection position of the cold air supply path 7;
A cooling jacket 13 is attached to the portion 1a facing the inner space, and an air supply path 15 for forming a gas curtain flowing downward along the inner surface of the peripheral wall portion 1a is provided, and the raw material supply path 2a is A cooling jacket 2b is attached to the nozzle 2 to be formed, and the porous body 4 forming the hot air outlet 4a from the hot air supply path 5 to the inner space of the casing 1 is formed into a substantially truncated conical shape, with its center P ' is provided so that it almost coincides with the vertical center P of the casing, and the nozzle 2 is arranged so that its blowing direction is downward, which almost coincides with the center P, and its tip is located inside the porous body 4. The outer circumferential surface 2c of the tip of the nozzle 2 is formed into a tapered surface whose diameter becomes smaller toward the tip, and a cold air outlet is provided from the cold air supply path 7 to the inner space of the casing 1. A spheroidizing device for thermoplastic powder and granular material, which is provided with a porous body 9 forming holes 9a and 9b. 4. The device according to claim 3, wherein at least a portion of the cold air outlets 9a, 9b blows cold air downward.