JPH0631493U - Granulator - Google Patents

Abstract

(57) [Abstract] [Purpose] A granulation rotary surface arranged in the granulation chamber, and a wet powder supply device for supplying the granulation powder and wet powder containing water to the granulation rotary surface. In order to obtain granules having a high hardness and a uniform particle size distribution, in the granulating apparatus for producing granules on the granulating rotating surface. [Structure] The rotating surface for granulation is formed by a cylindrical surface of a rotating body. The wet powder adheres to the rotary surface for granulation, the adhesion amount gradually increases, and when it reaches a certain size, it is torn off by centrifugal force to become granules. Since the granulation rotating surface is a cylinder, the centrifugal force is constant at any place on the rotating surface, so that the particle size becomes uniform. When the wet powder is supplied to the rotary surface for granulation by gas transportation, the hardness of the produced granules can be freely adjusted by adjusting the gas transfer rate.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a device for granulating powder, and more specifically, it supplies powder for granulation and wet powder containing mist-like water together with air to a rotary surface for granulation, and The present invention relates to a granulating device adapted to generate granules on a rotating surface for granules.

[0002]

[Prior art]

 Granulation of powder having a relatively small particle size, which is produced by spray-drying or other manufacturing methods, improves solubility, flowability, aesthetics, etc. of the powder, and is generally widely used for powdered foods and the like. In particular, as an apparatus for producing granules having a diameter of about 0.2 to 10 mm, an extrusion granulating apparatus that moistens powder and extrudes it through the holes of a perforated plate to form granules, and a rotary pan while moistening the powder Although rolling granulators and the like for sizing are known, these devices have the drawback that they cannot be used for some foods. For example, skim milk powder contains a large amount of lactose, so that when water is added, the powder particles are firmly solidified with each other, making it impossible to pass through a perforated plate in a wet state or to regulate the size by rolling. Moreover, since the coffee powder or the like becomes a mucous state when the water content is increased, it becomes impossible to granulate with the above apparatus. As a method or apparatus for granulating such powder into soft and highly soluble granules, (1) U.S. Pat. No. 3,554,760, (2) JP-A-62-6634 and (3) Special Features KAISHO 47-14344 is known.

The above (1) and (2) are methods or devices in which the powder is dropped, steam is sprayed onto the powder, the powder particles are aggregated in the air to be granulated, and then dried, and (3) is a disk-shaped method. It is a method and a device in which wet powder is adhered and agglomerated on the surface of a rotor, and the adhered and agglomerated soul is separated by a centrifugal force of a disk-shaped rotor to be granulated, and then dried.

[0004]

[Problems to be solved by the device]

 In the methods or devices of (1) and (2) above, the powder is agglomerated in the air, but in this case, the properties of the granules change depending on the strength of the adhesive force on the powder surface. If the adhesion is strong, large and hard granules are produced, and if the adhesion is weak, small and brittle granules are produced. Therefore, it is not possible to positively control the particle size and hardness of the produced granules, and it is not possible to granulate into large granules for powders with low surface adhesion such as powders with high protein content. Therefore, these methods or devices have a drawback that they can be applied only to products having strong adhesiveness such as coffee.

On the other hand, in the method and apparatus of (3), the size of the granules produced can be controlled to some extent by the magnitude of the centrifugal force of the disk-shaped rotor, but the hardness of the granules is the disk-shaped rotor. This method and apparatus also provide only some control, as there is a correlation to the rate at which the wet powder impinges. However, it can be said that the method and device of (3) are superior to the methods or devices of (1) and (2) in terms of granulation of articles having various properties and compositions.

The disadvantages of the method and apparatus disclosed in (3) above are as follows. 1) A disk-shaped disc is used as the rotating body, but the centrifugal force varies depending on the position on the disc (0 at the center of the disc and maximum at the outer periphery of the disc), so the following problems occur. . (A) Granules are not generated in the central part of the disk, the supplied wet powder is piled up as it is, and the piled powder is mixed into the product as a large lump. (B) Since there is a centrifugal force distribution in the radial direction from the center of the disk, the size of the granules is not the same depending on the place of generation, and the product particle size distribution is broad. (C) When the centrifugal force is adjusted by changing the rotation speed in order to change the size of the produced granules, the effect of the adjustment is difficult to appear because the centrifugal force distribution originally exists on the disc. (D) When the apparatus is scaled up, the existence of the centrifugal force distribution makes the calculation complicated, and an increase in processing amount cannot be expected. 2) Since the rotating shaft of the disk is installed in the vertical direction, all the produced granules are scattered in the horizontal direction, which causes the following problems. (E) Wet particles tend to adhere to the inner wall of the chamber in which the rotating body is installed. As described above, the method and device of (3) have many practical problems as a device. In view of the above-mentioned problems of the prior art, the present invention has the following contents (A11) to (A14). (A11) To provide a versatile granulating device capable of granulating powder having various properties and compositions. (A12) Provide a granulating device that can be easily scaled up according to the throughput. (A13) To provide a granulating apparatus capable of obtaining granules with high hardness and less breaking the granules by post-treatment. (A14) To provide a granulating device capable of obtaining granules having a uniform particle size distribution.

[0007]

[Means for Solving the Problems]

 Next, the present invention devised to solve the above problems will be described. The elements of the present invention are denoted by the reference numerals of the elements of the embodiments in order to facilitate correspondence with the elements of the embodiments described later. Items enclosed in brackets are added. The reason why the present invention is described in correspondence with the reference numerals of the embodiments described later is to facilitate the understanding of the present invention and not to limit the scope of the present invention to the embodiments. In order to solve the above-mentioned problems, the granulating apparatus of the present invention comprises a granulating rotating surface arranged in a granulating chamber, and a granulating powder and a wet powder containing water for the granulating rotating. A granulating device for producing granules on the rotating surface for granulation, comprising: a wet powder supplying device for supplying the granules to a surface, characterized by having the following requirement (A1): (A1) the granulating The rotating surface for use was formed by the cylindrical surface of the rotating body.

The cylindrical surface means a surface having a curvature among the surfaces forming the cylindrical shape. In the device of the present invention, it is possible to have a structure in which the cylindrical radii are made different along the rotation axis of the rotating body. In the device of the present invention, the cylindrical rotating body can be installed in a horizontal posture, a vertical posture, or any posture therebetween. In the device of the present invention, the powder can be supplied to the rotating body by free fall or gas transportation. As the wet powder supply device, a powder supply pipe which transfers powder with air and has a nozzle at its tip can be used. In this case, in order to scale up the equipment and increase the throughput, either increase the diameter of the powder supply pipe or increase the number of powder supply pipes. Further, in order to wet the powder supplied into the granulation chamber, a watering nozzle that sprays water in a mist form from the tip can be used. When the water addition nozzle is used to humidify the supply powder into a wet powder, the method of installing the water addition nozzle is to extend the water addition nozzle as described in the examples below, and place it inside the powder supply pipe. There is also a method of penetrating, but it is not necessary to take such an embodiment in particular, and a watering nozzle can be installed at a position different from the powder ejection port. In the apparatus of the present invention, when the cylindrical rotating body is installed vertically, the watering nozzle may be installed horizontally and the powder may be dropped onto the spray cone that is sprayed horizontally.

[0009]

[Action]

 Next, the operation of the present invention having the above-mentioned features will be described. In the conventional device, the wet bulk powder adheres to the rotating disk (on the rotating surface), the amount of the adhered powder gradually increases, and when it reaches a certain size, it is torn off by centrifugal force to form granules. In this series of processes, if the adhesive force of the granule is F, the peripheral velocity of the place where the granule is growing is u, the radius of gyration is r, the angular velocity is ω, and the mass of the grown granule is m, the granule grows. Assuming that the adhesive force and the centrifugal force are the same when moving away from the rotating body, the following equation (1) is established. F = mu2 / r = mrω2 …………………………………………………… (1) The mass m of the granules generated from the previous equation (1) is calculated by the following equation (2). Is obtained. m = (F / ω2) ・ (1 / r) ……………………………………………… (2) Therefore, since the rotating body is a disk in the conventional device, this disk R = 0 at the central part of r, and r becomes maximum at the outer peripheral part of the disk. As described above, the value of r is different at each position in the radial direction of the disk, and thus the value of the mass m of the generated granules is not constant at each position on the disk. That is, it is unavoidable that the particle size distribution of the produced granules becomes wide as long as the disk is used. In addition, m becomes infinite as r approaches 0 in the center of the disk, and it is impossible for particles to fly out due to the centrifugal force. In other words, the wet powder is only accumulating in the center of the disk, which is the cause of the large lumps in the conventional device.

The present invention solves the problem in the conventional device by forming the rotating body into a cylindrical shape and causing the wet bulk powder to adhere and grow on the cylindrical surface. When the radius of gyration is constant at all locations on the cylindrical surface of the present invention, the centrifugal force is constant on the entire cylindrical surface, and the mass m of the granules produced is also constant. Therefore, the particle size distribution of the granules is uniform, and since there is no place where the wet bulk powder is deposited, no large lumps are generated.

In the device of the present invention, it is possible to control the mass of the granules produced by changing the centrifugal force according to the rotation speed of the rotating body. Since there is no distribution, the particle size of the granules can be changed more sensitively to the change in the rotation speed, and the operation for obtaining the desired particle size is easy. Also regarding the scale-up of the device, in the present invention, since the throughput of the device is proportional to the surface area of the cylinder that produces the granules, increasing the diameter of the cylinder to extend the length of the cylinder increases the surface area of the cylinder. The number can be increased easily and the device can be scaled up very easily.

Further, in the conventional device, since the rotation axis of the disk is vertical, all the generated particles are scattered in the horizontal direction, so that the individual particles have a particularly large horizontal reach and velocity. In this case, there was a tendency for the particles to easily adhere to the inner wall surface of the chamber. In the device of the present invention, the cylinder can be installed with the axis of rotation being vertical, or in any other orientation, but it is most preferred to be installed horizontally. By installing the rotation axis in this way, the generated particles will be scattered in the vertical direction with the same probability as in the horizontal direction, and the speed of the particles scattered above will be attenuated by the action of gravity, and Even if it hits the ceiling, it hardly adheres, and particles scattered downward as well as the horizontal component of velocity are small, so they rarely adhere to the wall surface. Therefore, in the device of the present invention, the particles adhering to the inner wall surface of the chamber can be extremely reduced.

In the device of the present invention, when the wet powder obtained by mixing the powder supplied from the nozzle and the water content is collided with the rotating body, the powder may be classified depending on the type of the nozzle. In general, when powder having a particle size distribution is entrained in the jet air flow, fine particles tend to flow in the central part of the jet air flow and large particles to the outside. , Large grains may stick to one place and stick. In this case, the adhesive force of the granules is different between the fine powder portion and the large grain portion, so that the particle size of the generated condyle grains varies. In the device of the present invention, this problem can be prevented by changing the radius of the cylinder along the rotation axis of the cylindrical rotor.

Generally, in order to adjust the hardness of the produced granules, the distance between the rotating body and the watering nozzle is adjusted. This is because the higher the speed at which the powder collides with the rotating body, the stronger the binding of the individual particles and the harder the granules become. The binding force of the powder varies depending on the variety. For example, coffee powder has a relatively high binding force, and granules with good hardness can be obtained even with conventional equipment, but powders containing a large amount of protein, etc. In that case, the binding force of the particles is very weak, and it is difficult to obtain sufficiently hard granules. In this case, the particle size of the particles does not become so large that they become fragile, and in extreme cases, almost no wet powder adheres on the rotor. In the conventional apparatus, it was not possible to make such a powder having a weak binding force into a good hard granule simply by adjusting the distance between the rotating body and the water addition nozzle. In the present invention, when the powder is supplied by gas transportation, the powder and the rotating body can be made to collide with each other at a significantly higher speed than a fall by merely gravity. Further, the air transportation speed may be at least a wind speed at which the powder does not stay in the granulation chamber, and the collision speed of the powder can be freely adjusted within this range. That is, in the case of the gas transportation, the hardness of the produced granules can be freely adjusted by adjusting the gas transfer rate.

[0015]

【Example】

 Embodiments of the present invention will now be described with reference to the drawings, but the present invention is not limited to the following embodiments. (Embodiment 1) FIG. 1 is a partially enlarged vertical sectional view showing Embodiment 1 of the present invention. In FIG. 1, a water supply nozzle 15 is installed above the chamber 1, and a supply pipe 14 that supplies powder is installed above the water sprayed from the water supply nozzle 15. The powder is supplied from a funnel-shaped inlet 16 at the upper part of the supply pipe 14, and becomes wet powder by the water sprayed from the water addition nozzle 15. At the same time, it strikes the cylindrical rotor 17 and adheres to the surface. The rotating shaft 20 of the cylindrical rotating body 17 is held by bearings 19 and 21, and is rotated by a motor 18. The bearing 21 is supported by a plurality of columns supported by the outer wall of the chamber 1, and the bearing 19 is supported by the upper wall of the chamber 1. The wet powder adhering to the surface of the rotating body 17 appropriately grows, and the centrifugal force becomes larger than the adhering force at a certain size, so that the wet powder is separated into granules and scattered in the chamber 1. The granules scattered in the chamber 1 are conveyed to a predetermined drying device by a belt conveyor arranged below the chamber 1.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIG. In FIG. 2, a supply pipe 14 for supplying powder to the upper part of the chamber 1 and a water supply nozzle 15 are installed inside the supply pipe 14. The powder is supplied from the funnel-shaped inlet 16 at the upper part of the supply pipe 14 and becomes wet powder by the water sprayed from the water addition nozzle 15. At the same time, it hits the cylindrical rotor 17 and adheres to the surface. The rotating shaft 20 of the cylindrical rotating body 17 is held by bearings 19 and 21 and is rotationally driven by the motor 18, but the rotating shaft 20 is installed in a horizontal direction.

Third Embodiment Next, a third embodiment of the present invention will be described with reference to FIG. In FIG. 3, the powder is supplied from a pneumatic tube (a tube that transfers the powder by air, that is, gas). The powder is then ejected from the ejection port 28 from the powder ejection pipe 25 together with the air for air delivery. Inside the powder ejection pipe 25, a spray pipe 27 for ejecting the spray liquid from the nozzle 11 is installed, and water is sprayed from the tip of the spray pipe 27. The sprayed powder and the water sprayed from the spray tube are immediately mixed, the powder becomes a wet powder, and collides with the rotating body 17. After that, granulation is performed in the same manner as in each of the above-mentioned examples.

Next, the effects of the device of the present invention will be described with reference to test examples. (Test Example 1) (1) Specimen and device Device having a disk-shaped rotating body mounted thereon (conventional device) whose enlarged cross-sectional view is shown in FIG. 4 and device having a cylindrical rotating body mounted as shown in FIG. An invented device) was prototyped. The diameter of the chamber (made of acrylic) was 100 cm, the diameter of the disk-shaped rotating body (made of acrylic) was 11 cm, and the thickness was 0.3 cm. The diameter of the cylindrical rotating body (made of acrylic) was 6 cm, and the length was 12 cm. . These rotating bodies were rotated at 900 rpm by a motor (BL430A-AF manufactured by Oriental Motor Co., Ltd.), and water was sprayed at 10 g / min from a water addition nozzle (FU-3-6 type manufactured by Toyoei Co., Ltd.). The powder used for granulation was skim milk powder produced by a conventional method. (2) Test method The powder was supplied at a rate of 86 g / min by a constant quantity feeder (Kuma Engineering Co., Ltd., Accurate 600), transferred by a vibrating feeder (Shinko Denki Co., Ltd.), and atomized air 10 Nl / Minute, sprayed water was supplied to the chamber, and the operation was continued for 2 hours, and granulation was carried out by a conventional method. The obtained granules were sieved, the percentage of the weight of each sieved granule to the total weight was calculated, and the particle size distribution of the granules was examined. (3) Test results The results of this test are shown in Table 1. As is clear from Table 1, in the granules granulated by the conventional apparatus, the large lumps formed at the center of the disk occupy 40% and the particle sizes are irregular, whereas the granules granulated by the apparatus of the present invention. It was confirmed that the obtained granules had a clearly superior overall particle size uniformity. Although the test conditions and powder types were changed and tested, almost the same results were obtained.

[Table 1]

Test Example 2 This test was conducted to examine the hardness of granulated granules. (1) Sample and device Using the conventional device shown in FIG. 4 used in the test example 1 and the device having the cylindrical rotating body (device of the present invention) shown in FIG. A sample was used. (2) Test method The same as Test Example 1 except that the air feeding speed of the powder to the device of the present invention was set to 10 m / sec using a Breslider air feeder (K-10 type manufactured by Press Co.). Granules were produced by the method described in 1. The obtained granules were placed on a tray and dried in a thermostat (FC-610 manufactured by Advantech) at 50 ° C. for 20 minutes, and the granules were subjected to a destructive test using a rheometer (CR200D manufactured by Sun). . In the destructive test, a cylindrical cup having an inner diameter of 23 mm and a depth of 30 mm was filled with the granules, an aluminum cylinder having a diameter of 20 mm was penetrated by 15 mm, and the load repulsion force was measured to test the hardness of the granules. (3) Test results The results of this test are shown in Table 2. As is clear from Table 2, in the granules granulated by the conventional apparatus, the hardness is less than 2 kg in any measurement, whereas in the granules granulated by the apparatus of the present invention, the hardness is less than 2 kg. Was 2 kg or more, and it was found that the hardness of the granules was high. Therefore, the granules granulated by the device of the present invention are less likely to be destroyed by the treatment after granulation. Although the test conditions and powder types were changed and tested, almost the same results were obtained.

[Table 2]

[0020]

[Effect of device]

 The effects of the present invention are as follows. (1) A versatile device capable of granulating powders having various properties and compositions. (2) A device that can be easily scaled up according to the amount of processing. (3) Since the granules with high hardness can be obtained, the device is less likely to be broken by the post-treatment. (4) An apparatus that can obtain granules having a uniform particle size distribution.

[Brief description of drawings]

FIG. 1 is a partially enlarged vertical sectional view showing a first embodiment of the present invention.

FIG. 2 is a partially enlarged vertical sectional view showing a second embodiment of the present invention.

FIG. 3 is a partially enlarged vertical sectional view showing a third embodiment of the present invention.

FIG. 4 is a partially enlarged vertical sectional view showing an example of a conventional device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Chamber, 11 ... Nozzle, 12 ... Disk-shaped rotary body, 14 ... Supply pipe, 15 ... Water supply nozzle, 16 ... Funnel-shaped supply port, 17 ... Cylindrical rotary body, 18 ... Motor, 19 ...
Bearing, 20 ... Rotary shaft, 21 ... Bearing, 24 ...
Pneumatic tube, 25 ... Powder ejection tube, 27 ... Spray tube, 28 ... Jet port

Claims (1)

[Scope of utility model registration request] 1. A granulation rotary surface disposed in the granulation chamber, and a wet powder supply device for supplying a wet powder containing granulation powder and water to the granulation rotary surface. In a granulating device for producing granules on the granulating rotating surface,
A granulating apparatus having the following requirement (A1), (A1) The granulating rotating surface is formed by a cylindrical surface of a rotating body.