JPH0719728A - Method and apparatus for granulating and drying powder particles by operating air vibration wave - Google Patents

Abstract

PURPOSE:To provide a method for uniformly granulating and drying powder particles with small heating energy without scattering and an apparatus for executing the method. CONSTITUTION:The method for granulating and drying powder particles by operating air vibration wave comprises the steps of operating vibration air while supplying dry gas to powder particles (a) supplied from above a porous member 2 laterally provided in a case body 1 thereby to feed the particles (a) to a fluidized state in a material discharging direction, and injecting binder toward the particles (a) to granulate it at this time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for efficiently drying granules while granulating them.

[0002]

2. Description of the Related Art As a granulating / drying apparatus for granulating and drying a granular material, a granulating method utilizing mechanical vibration, a method in which the granular material is fluidized by air of a blower, etc. Various proposals have been made.

[0003]

However, in the granulation method utilizing mechanical vibration, the material may be clogged in a large number of small holes of the porous member, and the particle size and density of the granular material may be increased. Is difficult to adjust arbitrarily. In addition, the method of granulating the powder or granules by flowing with air is, as an example thereof, a porous member having a large number of small holes horizontally at the bottom of a hopper-shaped container body having an inlet and an outlet for materials. Air is blown from the blower onto the material from below the porous member, and a nozzle for binder is attached to the container body above the porous member, and the binder liquid is directed from this nozzle for binder to the fluidized bed of the material. Although it is designed to be sprayed, the particle size increases because the powder is fluidized by the flow velocity of air,
When the material has a heavy specific gravity such as metal powder, the flow velocity increases. There are also separations depending on the size of the particles and the specific gravity. Further, when the particle size of the material becomes small, abnormal phenomena such as slugging, channeling, and bubbling which hinder fluidization occur, and the quality of the obtained product becomes irregular and light.

The present invention has been devised in view of the above problems, and a granulation drying method capable of performing granulation drying quickly and evenly by applying vibrating air to powder or the like. Regarding the device.

[0005]

The present invention proposed to achieve the above object has the following constitution.
That is, according to the present invention proposed in claim 1, by applying oscillating air while supplying a dry gas to the granular material or the like supplied from above the porous member provided laterally in the case body, The powder or the like is made to flow and sent in the material discharge direction, and at this time, the binder is sprayed toward the powder or the like to granulate, and in the claim 2, the dry gas is hot air. Has become
According to the third aspect, the oscillating air is made to act under the condition that the inside of the case main body is further depressurized. In the present invention, the dry gas may be dry air, inert gas, heated air, or the like.

Further, in claims 4 to 6, a dry granulation device for carrying out the dry granulation method of the present invention is proposed, and in claim 4, both spaces divided vertically by a porous member are proposed. A case body in which a supply port and an exhaust port for powder or the like are provided in the upper space, an air vibration generator that applies oscillating air to the lower space of the case body, and the air is supplied above the porous member. The binder nozzle for spraying the binder onto the powder or the like and the heating device for heating the vibrating air from the air vibration generator to dry the powder or the like are provided. A decompression unit is provided to keep the inside of the body under reduced pressure.

Further, in claim 6, the exhaust port side of the case main body and the heating device side are connected to each other through a pipe to form a circulation line, and the circulation line is purged with dry air or this circulation line is circulated. A granulating / drying device has been proposed in which a dehumidifying unit is connected to a line and the dehumidifying air is circulated in the circulation line. In the present invention as described above, the basic idea is to apply vibrating air in the process of fluidizing and drying the powder and granules, and not only is it efficiently dried with a small amount of energy, but also the generation of dust is reduced to ensure quality. Is something that can be done.

Further, even light powder or the like can be taken out without floating more than necessary, so that it can be dried without problems due to waste heat or dust, and the density of the material can be easily adjusted and fluidized. It has advantages such as not inhibiting. The vibrating air used in the present invention is obtained by air vibrating a sound wave of a low frequency band to a medium frequency band, and its waveform may be arbitrarily changed such as a pulse wave or a sine wave.

[0009]

According to the present invention, when hot air is supplied to the powder particles or the like supplied from above the porous member laterally provided in the case body, it passes through a large number of small holes of the porous member to reduce low frequency or Vibrating air due to medium-frequency sound waves, that is, positive or negative air flow (pulsating wave) is applied, but this vibrating air is turned upside down without scattering powder particles, etc. To this end, it is uniformly granulated and dried. Note that an inert gas or the like may be vibrated instead of the vibrating air.

Further, in the present invention, the granular material or the like receives the vibrational energy of the vibrating air and is sent out in the material discharge direction and discharged, and at that time, the granular material jumps into contact with the hot air due to the vibrational energy of the vibrating air. Since the amount of heating energy is reduced, the drying can be performed quickly and efficiently. Furthermore, when vibrating air is applied in a state where the inside of the case body is depressurized, the drying speed becomes higher than that at atmospheric pressure.

Further, when the binder is sprayed, the positive and / or negative air oscillating wave fluidizes the layer itself such as powder particles without scattering, so that the material has a high specific gravity. Also requires less air flow than the conventional example, and works effectively even for materials with a low specific gravity. Furthermore, if the frequency of the vibrating air is arbitrarily changed, the degree of density of the powder or granular material, that is, the degree of heaviness / lightening can be arbitrarily adjusted. For example, the vibration air can be made heavier by increasing the frequency, and can be made light by lowering the frequency.

According to such a granulating / drying apparatus of the present invention, it can be used not only as a granulating apparatus but also as a drying apparatus when the binder nozzle is not used. The above device can be selectively used as a drying device and a granulating device.

[0013]

[First Embodiment] The granulating and drying apparatus and method of the present invention will be described in detail below with reference to FIG. The granulating / drying apparatus in the illustrated example is of a vibration flow type and includes a case body 1, and the case body 1 is oscillatably supported by a spring 12. The case body (trough) 1 has an internal space, which is vertically divided by a porous member 2 which is a punching plate, and the upper space 3 and the lower space 4 are formed by a large number of small holes 2a ... 2a. It is in communication. A powder supply port 5 is opened in the upper space 3, and an outlet 6 is opened in the other. The porous member 2 may be a mesh material.

A supply cylinder (not shown) is installed in the supply port 5 from above.
Are provided so as to face each other, and exhaust ports 7a, 7a are opened in the upper lid 7 of the case body 1. An exhaust pipe 8 is connected to the exhaust port 7a, and a blower 9 and a cyclone 10 are connected to the exhaust pipe 8, and dust (dry fine powder) is discharged from the cyclone 10. A microwave blocking plate 11 is provided inside the case body 1 so as to block the front part and the rear part. When air vibrations act on the case body 1, the elasticity of the spring 12 causes the spring body 12 to reciprocate up and down, so that the granular material a or the like is automatically transferred.
Is slightly inclined in the direction of the outlet 6, which facilitates the powder particles and the like a to be transferred by vibration.

A waveguide 20 is connected to the lower space 4, and an air vibration generator 21 is attached to the end thereof. The air vibration generator 21 includes, for example, although not shown, an air supply device having an intake port and an exhaust port, a rotary switching valve having four ports, a drive source for driving the rotary switching valve, and an air supply device. And a pipe (waveguide pipe) that connects the other two ports of the switching valve to the case body, and the rotary switching valve. The air vibration is generated by alternately switching the intake port and the exhaust port to the port.

The air vibration can change its waveform to a pulse wave or a sine wave as a low frequency or a medium frequency, but the amplitude of the waveform can also be changed. Although the ring blower type is adopted as the air supply device, a type such as a roots blower or a vacuum pump may be used. In addition to the rotary type, the air vibration generator 21 may be a bellows type or an engine type.

The waveguide 20 is connected to the lower space 4, and a flexible tube (not shown) having an adjustable length may be interposed at the end of the waveguide 20. By adjusting the length of the flexible tube, it is possible to set the energy of the air vibration to have the largest effect in the lower space 4 in accordance with the wavelength of the air vibration. The waveguide 20 is provided with a heating device 30 for generating hot air for heating the oscillating air. The heating device 30 includes a filter 31 that takes in outside air, a damper 32, and a blower 33 that is an air supply device.
And the heater 34, the waveguide 20 is bifurcated and communicates with the lower space 4 for drying.

Further, the exhaust port 7a (blower 9 in FIG. 1) side and the heating device 30 (filter 31 in FIG. 1) side are connected to each other through a pipe 35 to form a circulation line,
Dry air may be added to the circulation line, or the dehumidifying unit 36 may be connected to the circulation line to circulate the dehumidified air in the circulation line. On the other hand, the waveguide 40 for cooling communicates with the lower space 4, and the waveguide 40
Is also connected to the air vibration generator 21. Although a cooler 42 and a blower 41 are connected to the waveguide 40, the blower 41 may not be connected.

The upper space 3 of the case body 1 is provided with heating means 45 for microwave heating, far-infrared heating or the like corresponding to the drying zone. In this embodiment, the heating means 45
As it is heated by microwave,
Therefore, the heating means 45, as is well known, includes a mamagnetron oscillator, a waveguide, a power monitor, etc., but they are not shown.

A supply port 5 is provided on the porous member 2 of the case body 1.
Since powder particles or the like a are sequentially added and the air vibration from the air vibration generator 21 is applied to the waveguide 20, the vibrating air vibrates the hot air. The oscillating air acts as heating air that vertically reciprocates (pulsates) through a large number of small holes 2a and acts on the granular material a or the like, and inverts the granular material a or the like to make it flow, so that it is dried The effects are all over. That is, the hot air supplied to dry the powder a is vibrated by the vibration energy of the low-frequency sound waves, and the contact with the powder or the like is dramatically increased, so that the heat flow from the heater 34 is increased. Even if it is reduced, the drying effect is improved.

In the example shown in the figure, the heating means 4 is provided on the powder a.
Since heating from 5, for example, a microwave acts, the drying is promoted by a synergistic effect, and as a result, the granular material a is transferred while reciprocating (pulsating), and the heating energy of the microwave is the most effective. Acts in shape. In the present invention, since the granular material or the like a does not float and scatter, it is not discharged to the exhaust port 7a or the outside, and there is no risk of clogging.

When the powder or the like a is transferred to the cooling side, it is effectively cooled by air vibration as in the drying zone. The heating means 45 may not be additionally provided. The gas supply to the air supply device 33 is not limited to the outside air as in the embodiment, but dehumidified air, inert nitrogen gas or other gas can be supplied. The case main body 1 can be provided with a decompression means 44 such as a blower or a vacuum pump. By this, the inside of the case main body 1 is decompressed to lower the drying temperature and increase the drying speed of the powder or granular material a. be able to.

In FIG. 1, reference numeral 46 denotes a binder nozzle for spraying a binder so as to obtain granules of the granular material a supplied above the porous member 2.
A pipe 47 having a pump 48 attached to the binder nozzle 46 is connected to the binder nozzle 46, and the tip of the pipe 47 is placed in a binder liquid tank 49 containing a binder liquid which is adjusted and stored in advance. I am facing. Therefore, by driving the pump 48, a predetermined amount of the binder liquid in the binder liquid tank 49 is sprayed from the binder nozzle 46 onto the powder particles or the like a on the porous member 2 to be moistened and simultaneously dried. Granulation is achieved by forming solid crosslinks between the particles. The binder nozzle 46 has a structure in which the height of the spray can be adjusted by a mounting plate (not shown) as is well known.

The specific structure of the binder nozzle 46 is arbitrary. For example, as is well known, a needle-shaped fluid ejection passage gradually tapered toward the tip, or a second needle-shaped fluid ejection passage formed outside the needle-shaped fluid ejection passage, A high-pressure air may be ejected from the needle-shaped fluid ejection passage 2 as appropriate.

The attachment position of the binder nozzle 46 is not limited to the position shown by the solid line in FIG. 1, but may be the position shown by the chain line 46 or other positions, and the number thereof is arbitrary. The binder agent may be arbitrarily selected such as ethyl cellulose or polyvinyl alcohol, and is determined in consideration of various use conditions such as concentration, temperature, viscosity and the like. Further, in this embodiment, the wet binder is used as described above, but a dry binder can also be used.

As described above, in the first embodiment,
Since the binder nozzle 46 is attached to the case main body 1, it is possible to use the binder nozzle 46 as a granulating device for powder particles or the like a by ejecting the binder, and when the binder nozzle 46 is not used. Can also be used as a drying device. That is, one device can be selectively used for the drying device and the granulating device.

Next, the drying method and the granulating method of the present invention will be described below by using the granulating and drying apparatus shown in FIG. When the powder a is dried, the case body 1
The powder particles a are supplied from above the porous member 2 provided inside the porous member 2, and the air vibration generating device 21 causes vibrating air to act on the powder particles a on the porous member 2 to bring them into a floating flow state. While drying, it is sent out in the material discharge direction. At this time, the vibration energy of the vibrating air causes the powder particles or the like a to sufficiently flow, so that the powder is dried quickly and efficiently.

Next, when granulating the granular material a, etc., a step of supplying the granular material on the porous member 2, a step of applying vibrating air to the granular material a, and a discharge of the granular material a. In addition to performing each step in the same manner, a step of spraying a binder from the binder nozzle 46 on the powder a to be supplied above the porous member 2 to obtain granulation is added. Therefore, by the positive and / or negative air vibration wave,
Since the layer of powder and granules itself is fluidized, even a material having a high specific gravity may have a smaller air flow rate and heating temperature as compared with the conventional example, and also works effectively for a material having a low specific gravity.

Further, by arbitrarily changing the frequency of the vibrating air, it is possible to arbitrarily adjust the degree of density of the entire a (bulk) such as the granular material, that is, the degree of heaviness / lightening. FIG. 2 shows a second embodiment of the granulating / drying apparatus of the present invention. In this granulating / drying apparatus, a porous member 51 having a large number of small holes 51a is horizontally provided on the lower side inside a vertical case body 50, and an upper space 52 above the porous member 51 is supplied with powder particles from a supply port 53. The body a is introduced. The waveguide 5 is provided in the space 54 below the porous member 51.
5 is connected to this waveguide 55, and an air vibration generator 56 for applying a low-frequency or medium-frequency sound wave to the air to generate air vibration is connected to the waveguide 55 via a pipe 74.

An air supply device (blower) 57, which is a heating device 59, and a heater 58 are connected to the waveguide 55 via a pipe 59a so that vibrating air acts on the hot air. The hot air passes through the waveguide 55 and the lower space 54 and is passed through the small holes 51a of the porous member 51 to the upper space 52, and is dried while flowing the granular material a by the vertical reciprocating motion (pulsation) by vibrating air. Let At this time, the heated oscillating air serves as a large number of small holes 5 as heating air that reciprocates up and down.
Since the powdery material or the like a is made to flow by rolling through the la 1a, the drying effect is spread over the entire area. Further, the heating energy supplied at this time vibrates by receiving the vibration energy by the low-frequency sound wave and dramatically increases the contact with the particles of the powder or granular material. Therefore, even if the heat flow from the heater 58 is reduced, the drying is performed. The effect goes up.

In the illustrated example, since thermal energy acts on the powder or the like a from the heating means 60 such as microwaves or far infrared rays, the drying is promoted by a synergistic effect. Since it is in motion (pulsation), heat energy such as microwaves and far infrared rays from the heating means 60 acts for heating in the most effective form. Further, the powder or the like a does not float, and as a result, there is no possibility that it will rise and become clogged in the bag filter 61, or will be discharged to the outside from the exhaust pipe 62 via the exhaust port 62a. The motor 66
The exhaust gas discharged by the fan 63 driven by can also be changed to intake air. The dried particles or the like a are taken out from the product discharge port 64 into the receiving tank 65.

The case main body 50 is provided with a decompression means 67 such as a vacuum pump for the blower, and by decompressing the inside of the case main body 50, even if the drying temperature is lowered as compared with the drying temperature under normal pressure, powder The drying speed of the granules a and the like can be increased. In FIG. 2, reference numeral 70 denotes a binder nozzle for spraying a binder so as to obtain granules of the powder or granular material a supplied above the porous member 51. A pipe 71 having a pump 72 attached midway is connected to the binder nozzle 70. The tip of the pipe 71 faces a binder liquid tank 73 containing a binder liquid. Therefore, as described in the above embodiment, by driving the pump 72, a predetermined amount of the binder liquid in the binder liquid tank 73 is sprayed from the binder nozzle 70 onto the powder particles or the like a on the porous member 51. By wetting and drying at the same time, solid crosslinks are formed between particles to achieve granulation. The binder nozzle 70 has a structure in which the height of the spray can be adjusted by a mounting plate (not shown) as is known.

The attachment position of the binder nozzle 70 is not limited to the solid line position of FIG. 2, but may be the position of the broken line 70 or other positions, and the number thereof can be arbitrarily set. Also in the second embodiment, as in the first embodiment,
Since the binder nozzle 70 is attached to the case main body 50, it is possible to use the binder nozzle 70 as a granulating device for powder particles or the like a by ejecting the binder, and not to use the binder nozzle 70. It can also be used as a drying device.

The explanation of the granulating and drying method of the present invention using FIG. 2 will be omitted because it is understood in the explanation of FIG. In FIG. 2, 75 is a filter, 76 is a pedestal, 77 is an opening / closing valve for opening and closing the product discharge port 64, and 78 is a stirring blade, which may be omitted. Reference numeral 79 is a damper used for removing the dust attached to the bag filter 61.

In the case of the second embodiment, the exhaust port 62a (exhaust pipe 62 in FIG. 2) of the case body 50 and the air supply device 5 are provided.
7, a circulation line is formed by communicating with each other through a pipe 80 as indicated by a chain line, and dry air is purged to the circulation line, or a dehumidifying unit 81 is connected to the circulation line to connect the dehumidified air. It is also possible to circulate in the same circulation line.

The gas supply to the air supply device 57 is not limited to the outside air as shown in FIG. 2, but dehumidified air or other gas may be supplied. In the method and apparatus for granulating powders, the conventional apparatus shown in FIG. 4 (hereinafter referred to as conventional product)
And the device of the present invention shown in FIG. 2 (hereinafter referred to as the present invention product)
As a result of a comparative experiment using and, the results shown in Table 1 were obtained.

[0037]

[Table 1]

From Table 1, the following is clarified. That is, it was found that at the air flow rate M of the operating condition, the product of the present invention is about 50% as complete fluidized as compared with the conventional product. In other words, according to the product of the present invention, complete fluidization can be achieved with a smaller amount of air flow than in the conventional example, so various drawbacks of the conventional product, such as increase in power consumption and fluidization such as channeling and bubbling of materials, are obstructed. It is possible to prevent the occurrence of abnormal phenomena. The reason is that the product of the present invention is considered to prevent an abnormal phenomenon such as channeling, which is likely to occur in the conventional product, by applying an air vibration wave (pulsation wave). When the air is vibrated, that is, when positive or negative air flow is applied to the powder layer, it is considered that the vibration wave suppresses occurrence of abnormal phenomenon such as the above channeling.

Further, the hot air temperature N may be 50 ° C. for the product of the present invention as compared to 70 ° C. for the conventional product.
It was found to be dried at a% lower temperature. It is considered that the reason is that the air repeatedly moves up and down or left and right in the fine region of the powder layer due to the vibration wave, so that the heat exchange efficiency is extremely high. Binder liquid spray speed
O is 150 g / min for the conventional product and 200 for the product of the present invention.
Since g / min is sufficient, it is possible to spray approximately 30% faster than conventional products. The reason is considered to be the same as in the case of the hot air temperature.

Since the height Q of the binder nozzle is 480 for the conventional product and 420 for the conventional product, it is possible to lower the height by 60 and eject the powder, and the height of the powder in the fluidized bed is set low. Therefore, the position of the nozzle can be lowered accordingly. The water content R in the fluidized bed during granulation is 15-
It was found that the product of the present invention needs 12 to 12.5% WB with respect to 15.5% WB, so that a granulated product equivalent to the conventional product can be obtained in a state of being about 3% lower than the conventional product. The reason is considered to be the same as in the case of the hot air temperature.

[0041]

According to the granulating and drying method of the present invention, when the drying gas is supplied to the powder or granules or the like supplied from the porous member for drying, the vibrating air is used and the binder is sprayed. I am trying to do it. Therefore, the dry gas vibrates due to the air vibration wave, and the granulation is performed while rolling or floating the granules, etc. vertically and horizontally.Therefore, regardless of the specific gravity of the granules, etc. Even when the heating temperature is low and the heating temperature is low, the fluidization is completely performed without any abnormal phenomenon such as channeling. Therefore,
It is possible to obtain a uniform granulated product with less air consumption and heat. Further, by arbitrarily changing the frequency of the oscillating air, it is possible to arbitrarily adjust the degree of density of the bulk as a whole, that is, the degree of heaviness / lightening (the above, claim 1). .

When the inside of the case body is further depressurized and vibrating air is applied to the hot air to granulate, the granulation speed increases (claim 2). Further, the exhaust port side of the case body and the heating device side are connected to each other through a pipe to form a circulation line, and dry air is purged into the circulation line, or a dehumidifying unit is connected to the circulation line. If the dehumidified air is circulated in the circulation line, the gas used in the case body is reused, so that the heat quantity and the air quantity are saved (claims 3 to 5).

[Brief description of drawings]

FIG. 1 is a schematic diagram of a granulating / drying apparatus that is a first embodiment of the present invention.

FIG. 2 is a schematic diagram of a granulating / drying apparatus that is a second embodiment of the present invention.

FIG. 3 is a schematic view showing a conventional example of a vibration fluidization type drying device.

FIG. 4 is a schematic diagram showing another conventional example of a vibrating fluid type drying device.

[Explanation of symbols]

 a powder or the like 1,50 case body 2,51 porous member 3,52 upper space 4,54 lower space 5,53 supply port 8,62 exhaust pipe 20,55 waveguide 21,56 air vibration generator 30, 59 Heating device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Aroma Sanada 261 Umeki, Nakaizu-cho, Takata-gun, Shizuoka Prefecture (72) Inventor Sadaka Miwa 54-23, Fuji Village, Mishima City, Shizuoka Prefecture Inventor Koji Tada Hirakata City, Osaka Prefecture 1-10-4 Nagao Furniture Town, Matsui Mfg. Co., Ltd. Technology Development Center (72) Inventor Masaaki Nosaka 1-10-4 Nagao Furniture Town, Hirakata City, Osaka, Matsui Mfg. Co., Ltd. Technology Development Center (72) Inventor Konobu Takino 1-10-4 Nagao Furniture Town, Hirakata City, Osaka Prefecture Matsui Mfg. Co., Ltd. Technology Development Center (72) Inventor Kazuei Murata 1-10 4 Nagao Furniture Town, Hirakata City, Osaka Prefecture Matsui Manufacturing Technology Co., Ltd. Development Center (72) Inventor Osamu Matsui 6-526 Tanimachi, Chuo-ku, Osaka

Claims (7)

[Claims] 1. A vibrating air is applied to a powder or granular material or the like supplied from above a porous member laterally provided in a case main body while supplying a dry gas, so that the powder or granular material or the like is brought into a fluid state. The granulating and drying method is characterized in that the granules are discharged in the material discharging direction, and the binder is sprayed toward the powder or granules at this time to granulate. 2. The granulation drying method according to claim 1, wherein the drying gas is hot air. 3. The granulation drying method according to claim 1, wherein the inside of the case body is decompressed so that oscillating air acts. 4. A case main body having a supply port and a discharge port for a powder or the like in an upper space of both spaces vertically divided by a porous member, and oscillating air is applied to a lower space of the case main body. An air vibration generator, a nozzle for a binder that sprays a binder onto the particles or the like supplied above the porous member, and vibration air from the air vibration generator is heated to dry the particles or the like. A granulating / drying device comprising a heating device. 5. The granulating / drying apparatus according to claim 4, further comprising a decompression means for decompressing the inside of the case body. 6. The exhaust port side of the case main body and the heating device side are connected to each other through a pipe to form a circulation line, and dry air is purged to the circulation line, or a dehumidifying unit is attached to the circulation line. The granulating / drying apparatus according to claim 4, wherein the dehumidifying air is connected and circulated through the same circulation line. 7. The granulating / drying device according to claim 4, which can be used as a drying device by not using a binder nozzle.