JP2001009266A - Method of maintaining height of bed of continuous fluidized bed - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for maintaining the height of the bed of a continuous fluidized bed, excellent in heat transfer efficiencies, which can be used even in a horizontal, continuous fluidized bed granulator and is, in this case, widely applicable to various kinds of materials to be granulated having various average particle diameters and various physical properties, and in which the materials to be granulated can be granulated with high efficiency and in large quantities without the granulated materials being solidified on cooling. SOLUTION: This fluidized bed device has at least one fluidized zone for materials to be fluidized being fluidized in the horizontal direction whose total length in the fluidized direction thereof is preferably at least 375 mm, more preferably at least 1 m. In this case, On the back surface of the fluidized zone, a fluidized bed is provided which is so constituted that gas can uniformly pass through it upward but a part of the back surface of the zone, preferably a part of the back surface of the final zone is cut off to prevent the gas from passing, and the gas is passed through the fluidized bed upward so that the height of the bed of the fluidized bed is kept at least 80 mm, thereby maintaining the height of the bed of the continuous fluidized bed. When it is used in a horizontal, continuous fluidized bed granulator, granulation and drying can be performed with high efficiency, and in a cooling zone, the granulated materials are prevented from being solidified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention can be used for a novel continuous fluidized bed height maintaining method, more particularly for a continuous fluidized bed granulating and drying method. For example, granules having an average particle size in the range of about 30 to 1500 μm are not affected by the wind speed when flown in the horizontal direction, and maintain the desired layer height without causing granulation, drying and / or cooling. Fluidization method capable of maintaining efficiency and apparatus usable therefor, and fluids produced by such a method (granules such as seasonings)
The present invention also relates to foods, feeds, pharmaceuticals and the like using seasonings, soups and dairy products using the same.

[0002]

2. Description of the Related Art Conventionally, when soups and milk powder are granulated by using, for example, a horizontal continuous fluidized-bed granulator, a large amount of desired granules can be produced. In that case, granulation, drying, or cooling was performed using a large amount of gas such as air. However, in order to utilize the maximum air volume, the wind speed of the gas used by the conventional method is increased,
Depending on the particle size of the material to be dried and other physical properties, there are many cases in which it is difficult to stably fluidize the fluid because the fluid is blown off or the bed height is reduced. Therefore, an appropriate wind speed is selected and used within a range where such a case does not occur.

A typical fluidized bed granulation method for granulating based on a flow (see FIG. 1) actually used will be described below as an example of a conventional horizontal continuous fluidized bed granulator.

In the conventional method, the material to be processed (raw material 1) is fluidized horizontally in a fluidizing zone including a granulating zone 2, a drying zone 3 and a cooling zone 4 in succession, and hot air (60 ~ 100 ° C) and hot air (90
~ 130 ° C) and cool air (10-50 ° C) in the cooling zone
In each zone, air is blown upward through a dispersion plate provided on the lower surface of the zone, and the fluid is dried and cooled by the gas so that the target product can be granulated.

[0005] Regarding the wind speed of the gas blown from the lower surface, it is desirable that the bed height of the fluid is constantly and efficiently granulated and dried (in the case of granulation having an average particle size of 200 to 600 µm, the wind speed is 0.4 to 400 µm). About 0.8 m / sec, preferably 0.5
～0.7M / sec about, air volume 1 to 10 m ³ / min approximately), the bed height of the fluidized product is operated such that about 50 to 200 mm. Here, in the granulation zone 2, the fluid is granulated,
Drying is performed in the drying zone 3 and cooling is performed in the cooling zone 4.

According to the present inventors, when granulating and drying at a wind speed of 0.6 m / sec using this method, conventional soups and milk powder (average particle diameter of granules of about 200 to 600 μm) are used.
In the case of, the bed height of the target fluid can be maintained and granulation can be performed efficiently to some extent, whereas in the case of granulating seasonings, the average particle size is often small. The target layer height cannot be maintained because the granules are blown off by the influence of the wind (the average particle diameter is 100 to 200).
In the case of about μm, the layer height is as low as about 50 mm in all zones. It has also been found that, even with conventional soups, it is difficult to stably maintain the bed height of the fluid if the wind speed is further increased.

Accordingly, in order to increase the production efficiency of the fluid, while maintaining the bed height as high as possible during fluidization, it is possible to increase the wind speed without decreasing the wind speed in order to make maximum use of the air volume. Is required.

[0008]

SUMMARY OF THE INVENTION Under such circumstances,
It can be widely applied to various fluids, maintains a desired bed height for fluids with various average particle diameters and various physical properties, and has excellent heat transfer efficiency such as drying efficiency. There is a need for a fluidization method that enables efficient fluidization.

An object of the present invention is to develop a bed height maintaining method which is excellent in heat transfer efficiency (drying efficiency, cooling efficiency when used in a cooling zone, etc.) of a continuous fluidized bed. It can be applied to bed granulation equipment and can be widely applied to fluids having various average particle diameters and various physical properties in various fields from foods such as seasonings to feeds, pharmaceuticals, etc., and efficiently mass-fluidizes (granulation, (Drying, cooling, etc.).

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and have made the following considerations in the course of the research, and have obtained new findings.

1. An appropriate wind speed from below the fluidized bed is generally set between “minimum fluidizing speed” and “terminal speed” obtained from experiments and general formulas. The minimum fluidizing speed and the terminal speed differ depending on the particle diameter, specific gravity, shape, etc. of the fluid, but the following relationship was observed when the composition of the following example was used.

[0012]

When a fluidized bed apparatus has a plurality of fluidization zones such as a granulation zone, a drying zone, and a cooling zone, the set wind speed in each zone slightly varies depending on the average particle size of the fluid. Although it changes depending on the flow state and particle size distribution due to physical properties, the higher the temperature is possible (near the end velocity), the more gas can be used, and the better the heat transfer efficiency, which is advantageous.

From these facts, the average particle size is 200 to 3
When granulating about 00 μm granules, etc.
A wind speed of about 6 m / sec is considered to be the maximum. When a higher wind speed is to be used, or when a fluid having a smaller particle size is to be dried, it will blow off even at such a wind speed, and further improvement is required.

2. When the wind velocity of the gas from the lower surface of the fluidized bed is reduced, the granules do not blow off, and the bed height may be maintained in some cases. For example, when granulating and drying with a continuous fluidized bed apparatus having the three zones, when the wind speed of the first two zones is increased and the wind speed of the final zone is decreased, the bed height of the fluid in all zones is increased. Although it is possible to increase the heat transfer efficiency (drying efficiency,
When it is used in a cooling zone, the cooling efficiency etc.), that is, the production efficiency is reduced, and blocking is easily caused, resulting in an unstable state. In the cooling zone it also causes caking.

3. It is necessary to find a gas distribution method that enables the bed height of the fluid to be maintained at least 80 mm in all zones, and that makes the most of the air volume even for fluids of various particle sizes.

4. Block a part of the fluidized bed of the fluidization zone, and in particular, the final zone in the fluidization zone (including, for example, three horizontal zones of a granulation zone, a drying zone and a cooling zone in the horizontal direction). In this case, a part of the fluidized bed of the cooling zone, or one of the three zones if only one of the three zones is provided, preferably a part of the fluidized bed on the outlet side in the flowing direction is cut off, and gas passes upward. With such a configuration, even if the wind speed with respect to the gas passage surface is increased, the bed height of the fluid in the entire zone including the vicinity of the inlet and the vicinity of the outlet can be stabilized at the target height.

5. When granulating and drying with a fluidized bed apparatus having the above three zones as fluidizing zones, a part of the cooling zone, for example, a partial outlet on the outlet side is closed (for example, a perforated plate on the lower surface). By partially closing the holes, etc.) and making the cooling zone wind speed substantially equal to that of the other zones, a high bed height of the fluid is maintained, and as a result, the air volume of the cooling zone is increased. As a result, the cooling effect in this zone can be further enhanced, and consolidation can be prevented.

The present invention has been completed based on the above various new findings.

That is, the present invention has at least one fluidizing zone for a fluid flowing in the horizontal direction, for example, a granulation zone, a drying zone, a cooling zone, and the like. In a fluidized bed apparatus provided with a fluidization zone of at least 375 mm, more preferably at least 1 m, the gas can uniformly flow upward on the lower surface of the fluidization zone, but a part thereof is cut off, and A fluidized bed configured to block a part of the lower surface of the final zone so that gas cannot pass therethrough is provided, and the gas is passed upward through the fluidized bed so as to maintain the bed height of the fluid at least 80 mm. This is a method for maintaining the height of a continuous fluidized bed having the following formula:

A fluidized bed apparatus, preferably a horizontal continuous fluidized bed granulating apparatus, which can be used for granulation, drying and / or cooling of a fluid used or constituted so as to be usable in this method, In the present invention, fluids (granulated products) fluidized (granulated, etc.) in this way, and foods, feeds, pharmaceuticals, etc. containing or using these or used or seasonings, soups, dairy products, etc. are also included in the present invention. .

As one preferred embodiment of the fluidizing method, for example, the granulated material is fluidized at least in the granulating zone, the drying zone and the cooling zone in the horizontal direction, and the granulated zone and the drying zone are provided on the lower surface. In the cooling zone, the hot air blown upward through the dispersing plate, the cool air blown upward through the dispersing plate provided on a part of the lower surface, and the bed height of the fluid in each zone is at least 8
A granulation method including granulation and drying so as to be 0 mm can be given. As described above, when a part of the lower surface of the cooling zone, particularly a part of the outlet side in contact with the outlet is cut off, the bed height of the fluid in the entire zone can be maintained at a target height.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION (Fluidized bed apparatus) The fluidized bed apparatus used in the present invention is a horizontal continuous fluidized bed apparatus, which preferably has a total length of at least 375 mm, more preferably at least 1 m in the flow direction, A material having at least one fluidization zone such as a granulation zone, a drying zone, and a cooling zone is employed. Part of the fluidized bed of the fluidization zone (preferably the outlet side in the flow direction), particularly preferably the final zone, for example in a fluidized bed apparatus having only one fluidization zone, the one fluidization zone, the continuous formation In a fluidized bed apparatus including a granulation zone, a drying zone, and a cooling zone, a part of a fluidized bed in a fluidizing zone in contact with an outlet side such as a cooling zone is shut off so that gas cannot flow. The blocking part is preferably present on the outlet side in the flow direction, preferably on the outlet side. In particular, it is preferably 10 to 3 from the end of the zone substantially on the outlet side.
An area of about 00 mm, more preferably about 150 to 300 mm, and still more preferably about 150 to 250 mm may be blocked. It has also been found that this blocking area is not affected by the number of zones or the length or width of the zones.

As the fluidized bed apparatus in the present invention, a horizontal continuous fluidized bed granulator can be typically used. In that case, any granulation apparatus may be used as long as it can be granulated and dried by having at least a granulation zone, a drying zone and a cooling zone at the time of drying and fluidizing in the horizontal direction, and drying. A granulating device conventionally known as a granulating device and a granulating device to be developed in the future can also be used, but a gas blown through the lower surface of the cooling zone can be partially blocked as described above. Need to be configured.

It is to be noted that the fluidized bed apparatus (granulation apparatus, etc.) configured to directly carry out the fluidizing method of the present invention is, of course, configured to be able to carry out the fluidizing method of the present invention. Fluidized bed apparatuses, such as those which satisfy other requirements but do not include the above-mentioned shut-off area on the lower surface of the fluidized bed (since the cut-off area at that portion is easy to configure), all of which are included in the fluidized-bed apparatus of the present invention. included.

(Raw materials) There are no particular restrictions on the raw materials used for the fluid (granulated material, etc.), and various granulated materials required in all fields such as dairy products, seasonings, foods, feeds, pharmaceuticals, etc. Applicable to raw materials that can be used for things, etc.,
Especially the size of the average particle size obtained is not limited,
Usually, a fluid having an average particle size of about 30 to 1500 μm is employed.

Normally, as the average particle size increases, the wind speed can be increased accordingly. In particular, granulated materials which have a small average particle size in the past and have been difficult to use in the conventional method, for example, granules having an average particle size of less than 200 μm, for example, granules having an average particle size of about 30 to 100 μm, are particularly excellent in that they can be applied efficiently.

In the present invention, the form of the raw material supplied to the fluidized bed apparatus can be selected according to the purpose of fluidization. For example, when the fluid is dried or cooled, the fluid for drying or cooling is used, and when the granulation is performed (granulation to drying to cooling), a component mixture having a desired composition of the granulated material is used. (Solid content) or a composition containing a binder (binder) therefor.

For granulation, a binder is used. Water is mainly used as the binder,
Suitable binding aids in water, for example suitable ingredients in granules,
Others can be mixed and used. Such binder components include dextrin, starch and the like.

(The lower surface of the fluidizing zone of the granulating apparatus) The entire lower surface of the fluidizing zone (single or plural) has a uniform flow of gas upward except for the shut-off region which is one of the characteristic features of the present invention. It is configured to be able to. In this case, the material that can be used on the lower surface is not limited as long as the material allows gas to flow uniformly upward, that is, a material that has a passage hole through which gas can uniformly pass. For example, a dispersion plate can be used for that purpose. Preferred examples of the dispersion plate include a perforated plate, a wire mesh, a cloth, a porous plate, a bubble cap, and a combination thereof. Here, it is necessary to select a material such that the fluid does not fall from the lower surface of the fluidized bed according to the wind speed of the gas used. Air is usually used as the gas to be used, but an inert gas such as nitrogen gas can also be used.

For example, in the case of a granulator, the average particle size is 200
When fluidizing granules or the like having a size of ~ 1500 µm, the velocity of the gas passing through the fluidized bed is preferably from 0.4 to 2
m / sec, more preferably about 0.5 to 1.5 m / sec (relative to the gas passage surface), and the lower surface thereof depends on the average particle size and other fluctuations. It is configured such that an appropriate wind speed can be selected from below to above and gas can be blown therethrough.

Such a fluidized bed is composed of the above-mentioned dispersing plate, but there is no particular limitation on the material constituting it as long as it is used for the dispersing plate.

When the fluidized bed apparatus has a cooling zone in the present invention, the fluidized bed is partially cut off as described above (no air can be blown), and a perforated plate or the like is disposed as a dispersion plate on the lower surface of the remaining floor. Can be. As described above, it is preferable that the position at which the air blow is shut off be substantially at the outlet side of the cooling zone (see FIG. 3). From the outlet end, more preferably substantially 10 to 300 mm, more preferably 150 to 300 mm.
About 300 mm, more preferably 150 to 250 mm
It is good to cut off about mm.

There is no particular difficulty in the shut-off method, and appropriate measures may be taken so that the gas cannot flow through the fluidized bed, or a configuration necessary for that purpose may be adopted.

(Layer Height) One of the features of the present invention is to fluidize a fluid so as to maintain a specific bed height.

The bed height of the fluid is preferably at least 8 in one zone when having one fluidization zone and in each zone when having a plurality of zones.
0 mm, more preferably about 80 to 300 mm. That is, it is preferable to maintain the bed height of the fluid at a constant level in all zones in terms of heat transfer efficiency and, as a result, production efficiency, and the method of the present invention can be easily implemented.

When the bed height of the fluid is less than 80 mm, the flow is not stable and the flow becomes difficult. On the other hand, when the bed height exceeds 300 mm, the bed height is too high to be similarly stable, and neither is preferable.

(Product Temperature) In the present invention, when cooling with a fluidized bed apparatus having a cooling zone, it is necessary to cool the granule to 50 ° C. or lower from the viewpoint of preventing caking.
By maintaining the bed height of the fluid in the present invention, the product temperature can be easily reduced to 50 ° C. or less, which can contribute to prevention of caking.

(Product: fluid, granulated product, etc.)
Fluids such as granules produced by the method of the present invention are also included, and dairy products and seasonings obtained using the same are further included.
Other foods and beverages are also included. There is no particular difficulty in using the obtained granules for a seasoning, for example, as a seasoning, and a technique appropriately used in this field may be employed. For example, the obtained granules themselves or necessary granules may be used. Can be used by mixing other components or dissolving in various liquids.
Furthermore, it is also possible to provide such a granulated product or the like to foods and drinks that require it, or to perform various known processing treatments to obtain foods. For other products, the granules obtained for the purpose can be processed and used in the same manner.

The method for maintaining the layer height of the present invention can be applied to, for example, those requiring the production, drying, cooling, granulation, etc. of granular materials such as feeds and pharmaceuticals in fields other than the food field. Fluids (granules and the like) produced by using such a method and products using the same in the same manner are also included in the present invention.

[0041]

The present invention will be described below in detail based on examples and comparative examples.

Example 1 The horizontal continuous fluidized-bed granulator described above was partially modified and prepared based on the apparatus specifications shown in FIG. 2 (for other apparatus, see FIG. 1). The material was granulated. The dispersion plate is prepared with a bubble cap.

As a granulation (raw material), a powder seasoning is used, and its composition is as follows:

[0044]

The granulated product was dried and granulated using a binder under the following conditions. Table 1 shows the evaluation results.

[0046]

Water was used as a binder. Binder addition amount in granulation zone: 15
３０30 kg / hr. Average particle size of granulated product: 200 to 300 μm; bulk specific gravity:
0.45-0.58 g / ml.

In Example 1, the lower surface of the outlet end of the cooling zone was blocked over 250 mm from the end (FIG. 3).
reference. ) Blowing was not allowed. As the raw material 1, a granulated material having the above composition is supplied at a rate of 300 kg / hr as shown in FIG. The supplied granulated material is first fluidized in the granulation zone 2 (layer height: about 100 mm) and granulated and dried. The temperature of the hot air 5 blown at this time is 80 ° C.

In the next drying zone 3, a temperature of 110 ° C.
With hot air 6. Finally, it is fluidized in the cooling zone 4 and cooled and dried with the cold air 7 at 35 ° C. Granulated product 8
Is manufactured as shown in FIG. Fine powder and the like other than the granules are discharged to the cyclone 12. The compressed air 13 passes through the ejector line 9 and is introduced as shown in FIG. 1 in order to collect the cyclone collection product.

(Embodiment 2) In Embodiment 2, the cut-off area on the outlet side in Embodiment 1 is 150 m from the end on the outlet side.
m, and granulation and drying were carried out in the same manner as in Example 1 without any change.

(Comparative Examples 1 and 2) In Comparative Examples 1 and 2, granulation and drying were carried out in the same manner as in Example 1 using a full-surface dispersion plate without blocking the lower surface of the cooling zone. Only the air volume was set to the conditions shown in Table 1.

In each of the examples and comparative examples, the air velocity in the granulation and drying zone was constant at 0.6 m / sec and the air volume was constant at 5.0 m ³ / min. Table 1 shows the above results.

[0053]

[Table 1]

As is clear from the results of the above Examples and Comparative Examples and Table 1, the fluidized bed (dispersion plate) of each fluidizing zone, particularly in the area on the cooling zone outlet side, is closed to shut off the air flow. On the other hand, by increasing the wind speed in the cooling zone, the bed height of the fluid in the cooling zone can be increased to the same degree as in the other fluidizing zones. As a result, the air volume can be increased, the drying efficiency can be maintained, and the product temperature in the cooling zone can be reduced to 50 ° C. or less, and the consolidation can be prevented.

Further, from the above results, the length of the fluidizing zone (here, the cooling zone) near the outlet in the flow direction is 1 m.
In the above case, from the viewpoint of the air volume (wind speed × area [length]), the total air volume in the fluidized zone (cooling zone) is higher in Example 1 than in Comparative Example 2. Was also confirmed.

[0056]

According to the fluidizing method of the present invention using the fluidized bed apparatus having the above-described structure (partially shutting off the fluidized bed in the fluidizing zone, particularly shutting off the outlet side in the flowing direction), the wind speed is reduced as compared with the conventional method. Even if the height is increased, the height of the bed of the fluid can be maintained at a target height of at least 80 mm, and continuous operation can be efficiently performed.

In particular, when granulation is performed using a horizontal continuous fluidized-bed granulator, the granulated material is maintained in the horizontal direction in order through the granulation zone, the drying zone and the cooling zone to maintain the bed height. As a result, granulation and drying can be performed efficiently, so that it can be widely applied to fluids having various average particle diameters and various physical properties, and various granules can be efficiently produced. In particular, during cooling, solidification can be prevented.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a granulation / drying flow using a conventionally used horizontal continuous fluidized-bed granulator.

FIG. 2 is a diagram showing specifications of an apparatus used in the embodiment.

FIG. 3 is a diagram showing the device specifications used in the embodiment.
It is a figure showing the example of the state where the lower surface of the cooling zone and a part of distribution board were closed.

[Explanation of symbols]

 1: Raw material 2: Granulation zone 3: Drying zone 4: Cooling zone 5, 6: Hot air 7: Cold air 8: Product 9: Ejector line 10: Binder 11: Bag filter 12: Cyclone 13: Compressed air 14: Dispersion plate 15: Closed area of dispersion plate

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Nobumasa Takagi 1-1, Suzukicho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Ajinomoto Co., Inc. Kawasaki Plant (72) Inventor Hideaki Kawana 1-Suzukicho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture 1 Ajinomoto Co., Inc. Kawasaki Plant (72) Inventor Shiro Inoue 1-1, Suzukicho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Ajinomoto Co., Inc. Food Research Institute F-term (reference) 4G004 AA02 KA05 NA01 PA02 4G070 AA01 AB07 BB32 CB10 DA16 DA21

Claims (10)

[Claims] In a fluidized bed apparatus provided with a fluidizing zone for a horizontally flowing fluid, a gas can uniformly pass upward in a lower surface of the fluidizing zone, but a part of the gas is blocked. Maintaining the bed height of a continuous fluidized bed characterized by providing a fluidized bed configured to prevent gas from passing therethrough, and passing gas upward through the fluidized bed so as to maintain the bed height of the fluid at least 80 mm. Method. 2. The fluidized zone is constituted by a plurality of fluidized zones, and a lower surface of the final fluidized zone has a fluidized bed configured to block a part of the fluidized zone so that gas cannot pass therethrough. the method of. 3. The fluidized bed apparatus is a horizontal continuous fluidized bed granulator, and the fluidizing zone has at least a granulating zone, a drying zone and a cooling zone sequentially in the horizontal direction. 3. The method according to claim 1, wherein the gas passing through the zone is hot air, and the gas passing through the cooling zone is cold air. 4. The method according to claim 1, wherein the length of the fluidization zone in the flow direction is at least 375 mm or at least 1 m. 5. The method according to claim 1, wherein the fluid has a bed height of 80 to 300 mm. 6. A block portion of the zone having a fluidized bed in which gas passage is blocked is present at the flow direction outlet side, or 10 to 300 mm from the flow direction outlet side end,
3. A method as claimed in claim 1 or claim 2 wherein the portion is substantially blocked and gas cannot pass through the fluidized bed. 7. The fluidized bed through which the gas can uniformly pass upward is constituted by a dispersion plate (perforated plate, wire mesh, cloth, porous plate, bubble cap, a combination thereof, etc.). the method of. 8. A fluid having an average particle diameter in the range of 30 to 1500 μm, and when fluidizing granules having an average particle diameter of 200 to 1500 μm, the velocity of gas passing through the fluidized bed is increased with respect to the passage surface. 3. The method according to claim 1, wherein the speed is 0.4 to 2 m / sec.
The described method. 9. A fluid produced by the method according to claim 1 or 2, and a food, feed, or medicine such as a seasoning, a soup, a dairy product, etc. containing or using the fluid. 10. A horizontal continuous fluidized bed apparatus which is used in the method according to claim 1 or is configured to be usable.