JP2016010783A - Fluidized bed device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluidized bed device capable of reducing processing time while maintaining product qualities.SOLUTION: A fluidized bed device 1 comprises: a gas supply unit 8; a material container 7; a spray casing 6 in which a flow chamber 17 is formed; and a filter casing 5. The material container 7 comprises a perforated plate 22, a cylindrical straight section 23 and a reverse truncated cone-shaped tapered section 24. The spray casing 6 is formed in a tapered shape, the cross-sectional area of the upper end of which is larger than the lower end. For the fluidized bed device 1, when the amount of liquid added per unit perforated plate area converted to a heat quantity is B kJ/min cmand the PL value, which represents the liquid-absorbing ability of the particles, is PL, B is set to be PL×1.3≤B≤PL×3.2.

Description

  The present invention relates to a fluidized bed apparatus used for granulation, coating, drying treatment and the like of a granular material, and more particularly to a fluidized bed apparatus capable of producing a granulated product used for pharmaceuticals and foods in a short time. .

  In the fields of pharmaceuticals, cosmetics, foods, etc., fluidized bed apparatuses are widely used that fluidize powders and granules such as granules by a gas flow and perform processes such as granulation, coating, mixing, stirring, and drying. In the fluidized bed apparatus, an object to be processed such as powder is introduced into a cylindrical processing container, and a fluidized gas is supplied into the processing container to fluidize the powder particles. Water, a binder liquid, a coating liquid, or the like is supplied to the fluidized granular material by a spray nozzle, and processing such as granulation or coating is performed. At the lower part of the processing container, a breathable countersink plate formed of a metal mesh or the like is provided, and a processing gas is supplied from below the countersink plate. An object to be processed such as powder is fluidized by a processing gas while being held by the eye plate, and a binder liquid or the like is sprayed thereon to perform processing such as granulation.

JP 11-319534 A JP 2013-71104 A JP 2009-504584 A JP 54-138871 A JP 2002-292266 A

  On the other hand, also in the field of granulation treatment, reduction of treatment time is required from the viewpoint of production cost and the like. In this case, if the supply speed (supply amount per unit time) of water, binder liquid or the like supplied to the granular material is increased, the processing time is shortened accordingly. For example, if the supply speed is doubled, the processing time is theoretically halved. However, if the supply speed of the binder liquid or the like is increased, the granular material in the processing container becomes overhumid, a flow failure occurs and a lump is formed, or the granular material is consolidated into a conglomerate, There arises a problem that a good granulated product cannot be obtained.

  Therefore, when the supply speed of the binder liquid or the like is increased, it is necessary to increase the supply amount of the flowing gas so as not to cause a flow failure. However, when the supply amount of the flowing gas is increased, this time, the powder particles are greatly blown up in the processing container, and there arises a problem such as adhering to the filter. For this reason, conventionally, in this field, there has been a demand for shortening the time, but priority has been given to reliably obtaining a good product, and only granulation within existing conditions using existing equipment has been performed. The problem of time reduction was buried in stability.

  An object of the present invention is to provide a fluidized bed apparatus capable of shortening the processing time while maintaining product quality.

The fluidized bed apparatus of the present invention includes an air supply unit having an air supply chamber to which a processing gas is supplied from a gas supply source, and a raw material container that is disposed above the air supply unit and accommodates an object to be processed. A container, a spray casing disposed above the raw material container, and a fluidized chamber in which the object to be processed is floated and flowed by a processing gas, and a spray casing disposed above the spray casing for processing gas filtration A filter casing on which the filter is disposed, fluidizing the object to be treated accommodated in the raw material container with the treatment gas, and spraying a liquid to the fluidized object to be treated Thus, the fluidized bed apparatus performs the granulation treatment of the workpiece, and the raw material container is disposed at the bottom on the air supply unit side and holds the workpiece. A plate, a columnar straight portion that is disposed above the eye plate and extends upward with the same diameter, and an inverted truncated cone shape that is provided above the straight portion and has a large diameter upward. B (kJ / min · cm ² ), which is a value obtained by converting the amount of liquid added per unit pan area into heat quantity, and a PL value indicating the liquid absorption capacity of the workpiece When PL is set, B is PL × 1.3 ≦ B ≦ PL × 3.2. In addition, the “granulation process” in the present invention is a concept including not only granulation but also various powder processes such as coating and drying processes.

  In the fluidized bed apparatus, a height Hs of the straight portion may be formed to 1/6 to 1/2 with respect to a diameter of the countersink plate. Moreover, you may provide the flow velocity suppression part with a larger cross-sectional area in the upper side (filter casing side) of the said spray casing than the lower side (raw material container container side). In that case, you may form the said spray casing in the taper shape whose cross-sectional area is larger on the upper side than the lower side. Further, the eye plate is arranged radially in the eye plate, the slit for generating a swirling airflow of the processing gas above the eye plate, and arranged in the form of dots on the eye plate, A vent hole that suppresses the formation of the swirling airflow by the slit while the processing gas is ejected upward may be provided.

On the other hand, in the fluidized bed apparatus, B may be preferably PL × 1.7 ≦ B ≦ PL × 3.2. Further, the amount of heat consumed when the processing gas passes through the fluidized bed apparatus is expressed as Q (Q (kJ / min) = (supply air temperature−exhaust temperature) (K) × air volume (kg / min) × air specific heat ( J / g · K)), and when the heat consumption Q per unit pan area is C (= Q / Sa) (kJ / min · cm ² ), C is the wind speed (cm / min) × 8 It is good also as exceeding .5 * 10 < ^-5 > kJ / cm < ³ > and wind speed (cm / min) * 11 * 10 < ^-5 > kJ / cm < ³ > or less. Further, the fluidized bed apparatus may be an apparatus in which the area of the countersink plate exceeds 0.1 m ² . In addition, the PL value may be 0.1 or more and 0.5 or less.

According to the fluidized bed apparatus of the present invention, a columnar straight portion is provided above the plate of the raw material container, and a value obtained by converting the amount of liquid added per unit plate area into a calorific value is expressed as B (kJ / min · cm ^2), when the PL value indicating the liquid absorbing capacity of the article to be treated was a PL, by the B and PL × 1.3 ≦ B ≦ PL × 3.2, equivalent to that of existing granules Can be manufactured in a shorter time than conventional. Thereby, the granulation process can be performed without deteriorating the product quality, and the processing time can be shortened.

The front view which shows the external appearance of the fluidized-bed apparatus which is one Example of this invention. It is a side view of the fluidized bed apparatus of FIG. It is explanatory drawing which shows the difference in the cross-sectional area of the flow chamber used as the taper shape. It is explanatory drawing of height Hs of the straight part of a raw material container. (A) is explanatory drawing which shows the whole structure of an eye plate, (b) is sectional drawing which shows the structure of a slit. It is the table | surface which put together the result of having performed the granulation process in the conventional fluidized bed apparatus (conventional machine) and the said fluidized bed apparatus (improved machine), changing the spray speed (liquid speed) and supply air temperature. It is the graph which compared the particle size distribution in (a) 30 type | mold and (b) 120 type | mold with the conventional fluidized bed apparatus and the said fluidized bed apparatus. (A) is a table showing a standard minimum air volume and an eye plate area (cm ² ) used in the initial stage of granulation for each apparatus scale, and (b) is a table showing a C value calculated based on the table of (a). It is. (A) is a table showing the liquid speed (g / min) and eyeplate area (cm ² ) for each apparatus scale, and (b) is a B value per unit PL value calculated based on the table of (a). It is a table. However, the liquid speed is for a solution containing 7% of a binder (solid content), and 93% of the volatile content is the amount of addition. The processing conditions and the values of C, B, A (= B / C) were calculated for each of the 30, 60, 120 type apparatuses when the dew points of the processing gas supplied to the apparatus were 14 ° C. and 6 ° C. It is a table. Note that the 30 type is a type of apparatus capable of processing approximately 30 kg with a granular material having a bulk density of 0.5 g / mL. Similarly, the 60 type is a type of apparatus capable of processing 60 kg and the 120 type is capable of processing 120 kg. It is. It is the graph which plotted the calculation result of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a front view showing an appearance of a fluidized bed apparatus according to an embodiment of the present invention, and FIG. 2 is a side view of the fluidized bed apparatus of FIG. The fluidized bed apparatus 1 shown in FIG. 1 is used, for example, for the production of granulated products such as granules for tableting used in the manufacture of pharmaceuticals and foods, and granular pharmaceuticals and foods. A binder liquid and a coating liquid are sprayed on the granular material fluidized by the gas.

  The fluidized bed apparatus 1 is provided with a cylindrical processing container 2 in which a granular material (a material to be processed) serving as a raw material is accommodated and a desired granulation coating process or a drying process is performed. The processing container 2 is formed of stainless steel and is supported by a support base 3 as shown in FIGS. The processing container 2 of the fluidized bed apparatus 1 has a configuration in which a cover unit 4, a filter casing 5, a spray casing 6, a raw material container 7 and an air supply unit 8 are stacked in order from the top. At the time of the granular material processing, the units such as the cover unit 4 and the filter casing 5 are fastened in an airtight manner by a ring-shaped seal member.

  The cover unit 4 is fixedly supported on the support base 3 by a cover bracket 11. An exhaust port 12 is formed at one end of the cover unit 4, and an exhaust duct (not shown) is connected to the exhaust port 12. A filter casing 5 formed separately from the spray casing 6 is attached to the lower surface side of the cover unit 4. The filter casing 5 is provided so as to be movable in the vertical direction by an elevating mechanism 13 incorporated in the support base 3. A disc-shaped top plate 14 is fixed to the upper end portion of the filter casing 5, and a cartridge filter 15 is attached to the top plate 14. The top plate 14 is welded and fixed to the inner periphery of the filter casing 5 without a gap so that powder leakage does not occur between the casing and the top plate.

  The spray casing 6 is attached to the support 3 by a swing bracket 16 and is provided so as to be able to swing in the horizontal direction. In the fluidized bed apparatus 1, since the spray casing 6 is separated from the filter casing 5, the cartridge filter 15 in the filter casing 5 can be accessed from below by retracting the spray casing 6 in the horizontal direction. ing.

A flow chamber 17 is formed in the spray casing 6. The spray casing 6 has a tapered shape in which the diameter of the upper side of the side wall portion 18 is increased. In the fluidized bed apparatus 1, the cross-sectional area of the upper end 17a of the fluid chamber 17 is about 1.3 times the cross-sectional area of the lower end 17b (for example, the upper end 17a: φ820 mm, 0.53 m ² , lower end Part 17b: φ720 mm, 0.41 m ² , see FIG. 3). As described above, when the upper end portion 17 a side of the flow chamber 17 is formed to have a larger diameter than the lower end portion 17 b side, the wind speed of the processing gas decreases as the flow chamber 17 moves upward. That is, the upper end portion 17a side of the flow chamber 17 functions as a flow rate suppressing portion, and thereby the flow height of the granular material is suppressed. Therefore, the burden on the cartridge filter 15 can be reduced, and the adhesion of the granular material to the filter casing 5 is also reduced.

  A spray gun 19 for spraying a binder liquid or a coating liquid onto the granular material in the fluid chamber 17 is attached to the side wall portion 18 of the spray casing 6. Binder liquid or the like is supplied to the spray gun 19 from a pump provided outside the apparatus through a tube (not shown). The fluidized bed apparatus 1 employs a one gun side spray system in which one spray gun 19 is arranged on the side wall portion 18. As described above, by arranging the spray gun 19 on the side wall portion 18, the powder particles are not deposited on the spray gun, the maintenance becomes easy, and the generation of agglomerates due to the deposits is suppressed, and the granulation quality is improved. Improved. In the fluidized bed apparatus 1, a high performance gun capable of high speed spraying is used as the spray gun 19 in order to shorten the processing time.

  A raw material container 7 is arranged below the spray casing 6, and a granular material to be processed is put into the raw material container 7. The raw material container 7 is attached to the carriage 20 so as to be freely movable on the floor surface. A raw material storage chamber 21 is formed inside the raw material container 7, and a gas tray plate 22 having air permeability is provided below the raw material container 7. The granular material charged into the raw material storage chamber 21 is supported on the eye plate 22. The raw material container 7 is composed of a columnar straight portion 23 and an inverted frustoconical tapered portion 24. The straight portion 23 is disposed above the countersink plate 22 and extends upward with the same diameter. The taper portion 24 is provided above the straight portion 23 and has a larger diameter toward the upper side. The height Hs of the straight portion 23 is about 1/6 to 1/2 of the diameter φ of the eye plate 22 (for example, Hs = 80 for the eye plate 22 of φ497 mm). About 250 mm and φ900 mm for the countersink plate 22, Hs = 150 to 450 mm, see FIG.

  Thus, by providing the straight portion 23 adjacent to the eye plate 22, a decrease in the wind speed of the processing gas after passing through the eye plate can be suppressed as compared to the case where the taper portion is provided directly above the eye plate. . That is, the straight part 23 functions as a flow rate maintaining part, thereby promoting the flow of the powder and improving the stirring and mixing performance. In addition, although the height of the raw material container 7 itself becomes high by installation of the straight part 23, the height of the whole apparatus can be maintained equivalent to the conventional machine by suppressing the height of the spray casing 6. As described above, in the fluidized bed apparatus 1, the upper part of the spray casing 6 is a flow rate suppressing unit, and the flow height can be suppressed while the air volume is large, so the height of the spray casing 6 is suppressed more than the conventional machine. It becomes possible. For this reason, the straight portion 23 can be provided without increasing the height of the entire apparatus.

  As shown in FIG. 5A, the eye plate 22 is provided with radially arranged slits 25 and vent holes 26. The slit 25 is comprised from the opening part 25a and the wind direction piece 25b formed so that it might cover the opening part 25a (refer FIG.5 (b)). The processing gas is led out in the circumferential direction from the opening 25 a, whereby a swirling airflow of the processing gas is generated above the countersink plate 22. On the other hand, the vent hole 26 is a hole penetrating the countersink plate 22 in the vertical direction, and is provided in the form of dots in order to suppress the pressure loss of the processing gas supplied toward the countersink plate 22. The processing gas that has passed through the vent hole 26 is ejected upward as it is and merges with the air stream ejected from the slit 25. That is, a swirling airflow that has passed through the slit 25 and an upward jetting airflow that has passed through the vent hole 26 exist on the countersink plate 22.

  In this case, the upward jetted airflow of the vent hole 26 has an action of weakening the swirling airflow formation by the slit 25. Therefore, in the apparatus for obtaining the swirling airflow, the presence of the vent hole 26 is not necessary. On the other hand, considering the pressure loss of the processing gas, a configuration such as the slit 25 having the wind direction piece 25b is not preferable. On the other hand, in the fluidized-bed apparatus 1, the process by large air volume is assumed and there exists a possibility that the too strong whirling airflow may be formed by the slit 25. FIG. An excessively strong swirling airflow may hinder the granulation process, and the countersink plate 22 relaxes / suppresses it by the upward jetting airflow from the vent hole 26. In other words, the vent hole 26 suppresses the generation of excessive swirling airflow while reducing pressure loss, and the countersink plate 22 is appropriately swiveled even under a large air volume due to the synergistic action of the slit 25 and the vent hole 26. It is a hybrid eye plate that provides airflow.

  An air supply unit 8 having an air supply chamber 27 inside is installed below the raw material container 7. The air supply unit 8 is connected to an air supply duct 28 that communicates with the air supply chamber 27. The air supply duct 28 is connected to an air supply source (not shown) provided outside the apparatus. A processing gas (fluidized air) for fluidizing the granular material is supplied into the air supply chamber 27 via the air supply duct 28. The processing gas in which the powder is in a fluid state is cleaned by removing fine solid particles by the cartridge filter 15 and then discharged from the exhaust port 12 to the outside of the apparatus.

  In such a fluidized bed apparatus 1, when flowing air (process gas) is supplied from the air supply duct 28 to the air supply chamber 27, the air flows into the raw material storage chamber 21 through the eye plate 22. As described above, the countersink plate 22 is a swirling flow generating pan, and the flowing air that has passed through the countersink plate 22 forms a swirling airflow, and blows up the granular material in the raw material storage chamber 21. At that time, an excessive swirling airflow is suppressed by the action of the air holes 26 in the countersink plate 22, and an appropriate swirling airflow is generated even with a large air volume. Moreover, since the straight part 23 is provided in the lower part of the raw material container 7, the flowing air is blown up in a state where the flow velocity is maintained, and the flow of the granular material is promoted, so that the inside of the raw material storage chamber 21 and the flow chamber 17. Good stirring and mixing is performed at On the other hand, the powder body flows greatly with a large air volume, but the spray casing 6 has a tapered shape, and the upper end portion side of the flow chamber functions as a flow rate suppressing portion. It can be suppressed. For this reason, adhesion to a filter or a can body is suppressed little while active stirring and mixing are performed. Then, in this state, a spraying of a binder liquid or a coating liquid from the spray gun 19 in a spraying manner allows the granule to be granulated or coated.

  In a normal granulation process, spraying is performed at a liquid speed higher than the drying capacity. Then, spraying is performed up to a specified amount while accumulating a binder liquid such as water or ethanol or a solvent of the coating liquid in the raw material granular material. However, if liquid such as water or ethanol is accumulated in the raw material, the fluidity is lowered. In many cases, the air volume is increased in the middle of the treatment. Therefore, the amount of accumulated liquid in the raw material rises to some extent at the beginning of granulation, and when liquid such as water or ethanol accumulates to some extent, the operating conditions are changed (mainly the air volume increases), and the increase in the accumulated liquid volume is moderated. Alternatively, spraying is performed to a specified amount while maintaining a constant or slightly descending feeling. In general, the binder liquid or the like is sprayed continuously or intermittently, and the liquid speed is generally constant or gradually increased.

  On the other hand, as the granulation process is performed, fine powder adheres to the cartridge filter 15 and the filtration efficiency is lowered. Therefore, it is necessary to appropriately replace and clean the filter. In that case, in the fluidized bed apparatus 1, first, the carriage 20 is moved and the raw material container 7 is pulled out of the apparatus. Next, the spray casing 6 is swung in the horizontal direction, and the lower part of the filter casing 5 is opened. After retracting the spray casing 6 to the side, the filter casing 5 is lowered from the set position to the maintenance position.

  After the filter casing 5 is lowered to the maintenance position, the cartridge filter 15 is removed from the filter casing 5, and the filter is replaced or cleaned. As described above, when the cartridge filter 15 is moved to the maintenance position below the apparatus and the filter is removed there, the filter can be maintained at the low position, and the workability is greatly improved as compared with the work at the high position. Improved. After replacement of the cartridge filter 15 and the like, the filter casing 5 is raised from the maintenance position to the set position. After the filter casing 5 is installed at a predetermined set position, the spray casing 6 is swung in the horizontal direction and set to the original predetermined position.

  After setting the filter casing 5 and the spray casing 6 at predetermined positions, the raw material container 7 placed on the carriage 20 is disposed below the spray casing 6. Then, a raw material container 7 is pushed upward by a lift mechanism (not shown) provided in the air supply unit 8, and the spray casing 6, the filter casing 5, and the cover unit 4 are brought into close contact with each other from the lower side. Thereby, the processing container 2 becomes a state which can be flow-processed, and the granulation coating process of a granular material is implemented by performing supply of flowing air, spraying of a coating liquid, etc.

  Therefore, in order to confirm the processing performance in the fluidized bed apparatus 1, a conventional fluidized bed apparatus (spray casing: straight body without taper, no straight portion 23, a normally used breathable eye plate formed of a wire mesh) In a fluidized bed apparatus 1 (30 type, 120 type) using a plate, granulation was performed by changing the spray speed (liquid speed) and the supply air temperature. FIG. 6 is a table summarizing the results, and FIG. 7 is a graph comparing the particle size distribution in (a) 30 type and (b) 120 type between the conventional fluidized bed apparatus and the fluidized bed apparatus.

  As shown in FIGS. 6 and 7, according to the experiments by the inventors, the liquid speed: standard × 1.5 and the supply air temperature up to 100 ° C. are manufactured for both the 30 type and 120 type conventional machines. The physical properties of the granules were good. However, when the liquid speed: standard × 2.0 and the supply air temperature is 120 ° C., the number of coarse particles increases, the particle size distribution becomes broad, and the physical properties are NG. On the other hand, in the treatment using the fluidized bed apparatus 1, a good particle size distribution can be obtained for both the 30 type and the 120 type even when the liquid speed is: standard × 3.0 and the supply air temperature is 120 ° C. ( In addition, the processing time has been reduced to less than half.

  Thus, in the fluidized-bed apparatus 1 of this invention, by providing the straight part 23 in the raw material container 7, the flow-rate fall of the processing gas after passing a plate is suppressed, and the flow of a granular material is activated. Therefore, the stirring and mixing performance can be improved as compared with the conventional machine. For this reason, it becomes possible to supply air at a higher temperature and a larger air volume than the conventional machine, and accordingly, the spray liquid speed can also be increased, so that the granulation processing time can be shortened. Moreover, since the raw material blow-up accompanying the activation of the flow is effectively suppressed by the taper casing, an increase in the load on the filter can be avoided. Furthermore, an excessive swirling air flow accompanying a large air volume is also appropriately suppressed by the hybrid eye plate structure provided with the vent holes 26, and the flow of the granular material can be activated by an optimum processing air flow.

By the way, in the conventional granulation method, excluding a small machine / experimental machine having an area of less than 0.1 m ² , for example, in a 30-120 type apparatus, the initial stage of granulation (temporal of the whole granulation process) In the initial 1/3 range), the supply speed of the binder liquid (hereinafter, liquid speed) is about 290 to 810 g / min, and the flowing gas is about 60 to 80 ° C. · 6.0 to 16.0 m ³ / min. It is carried out under the conditions. In order to shorten the processing time under such conditions, it is required to increase the liquid speed, but at the same time the flow rate of the flowing gas (hereinafter referred to as air volume) must be increased. Therefore, it is not just a matter of increasing the liquid speed and the air volume. In addition to air volume, various factors such as temperature conditions, powder absorption capacity, throughput, and equipment size need to be considered in order to achieve a good granulation treatment. Usually, safe processing conditions are employed.

  Under such circumstances, the present inventors reconsidered the conventional processing conditions under the fluidized bed apparatus 1 described above in order to achieve the proposition of shortening the processing time, and reconsidered the essential conditions in the granulation processing. did. As a result, the present inventors focused on the amount of heat in the apparatus during the granulation process, and by capturing various conditions of the granulation process as the amount of heat, a granulated product equivalent to the conventional one can be obtained in a shorter time than before. It was found that it can be manufactured. Hereinafter, the granulation process based on such a new viewpoint will be described.

Here, first, the amount of heat Q consumed by the processing gas as it passes through the apparatus is considered. This consumed heat quantity Q substantially corresponds to the drying capacity and can be expressed by the following equation.
Q (kJ / min) = (Supply temperature-Exhaust temperature) (K) x Airflow (kg / min) x Air specific heat (J / g · K)
For example, when the solvent of the binder liquid or the coating liquid is water, when the intake air state is 20 ° C. and the relative humidity is 40%, the temperature is increased when the air is heated to 70 ° C. and granulation is started. As a result, the relative humidity decreases from 40% to 3%. Here, when spraying is started, the humidity in the processing container gradually increases, and rises toward a relative humidity of 100% along the adiabatic cooling line while evaporating the moisture of the granulated material. When the relative humidity reaches 100%, the moisture evaporation rate becomes constant, and the exhaust temperature does not fall below a certain value (for example, 28 ° C.). The amount of heat consumed Q becomes a minimum value at the start of spraying when the air volume is small and the exhaust temperature is high. Further, after the start of spraying, the water vapor of the processing gas becomes saturated (relative humidity 100%), and reaches a maximum value when the exhaust temperature is lowered to the minimum value. A state in which the exhaust temperature is the lowest temperature to a steady state, the Q value of this time and Q _0.

  Of the heat consumption Q, the amount of heat (= drying capacity) actually consumed to evaporate water needs to be multiplied by a predetermined thermal efficiency coefficient in consideration of heat radiation from the processing container. This thermal efficiency coefficient varies depending on the apparatus scale and the air supply conditions.

Moreover, since the heat consumption Q is proportional to the air volume, as can be seen from the above equation, the value varies depending on the device scale. As long as the air volume per charging amount is not excessive, it is advantageous that the air volume is large because the drying capacity is high, but the maximum value is determined for each apparatus. Therefore, here, Q is divided by the area of the air circulation portion in the eye plate 22 (hereinafter referred to as the eye plate area), and a value excluding the influence of the device scale is used. Here, the value obtained by dividing the Q ₀ earlier in perforated plate area Sa, that is, considering the heat consumption per unit th dish area, and its value as _{C = Q 0 / Sa (kJ} / min · cm 2). FIG. 8 (a) is a table showing the standard minimum air volume and the eye plate area (cm ² ) used at the initial stage of granulation for each apparatus scale, and (b) is calculated based on the table of (a). It is a table | surface which shows C value (refer FIG. 10 for the detail of each value).

Next, the liquid to be sprayed is also grasped from the viewpoint of the amount of heat. Here, a value excluding the solid component in the spray liquid is defined as a liquid addition amount, and the amount of heat possessed by the liquid addition amount is calculated by multiplying the liquid addition amount by latent heat of vaporization. That is, the amount of heat necessary to evaporate the liquid is considered. In order to remove the influence of the scale of the device, this value is also divided by the scale area Sa and converted into the amount of heat per unit scale area. The value is B (kJ / min · cm ² ). This value is roughly proportional to the liquid speed. For example, in the case of a mixed solution of water and ethanol, the amount of heat is proportionally distributed according to the mixing ratio in the case of a mixed liquid of water and ethanol. Moreover, the maximum value of the liquid addition amount per preparation amount differs for each apparatus and for each prescription.

  On the other hand, in the granulation process, it is necessary to consider the liquid absorption capacity of the raw material. As described above, in the granulation process, spraying is performed up to a specified amount while accumulating liquid such as moisture in the raw material. Therefore, in the granulation treatment, the plastic limit of the material is conventionally used as an index (PL value) as the liquid absorption capacity of the raw material. Air is present between the particles of the powder, and when all of this is replaced with liquid (water), it becomes a plastic material (a substance having the property that strain remains even if it is removed when an external force is applied). And if a liquid is added more than this, even if external force is applied, it will return, and this limit is called a plastic limit. Here, the liquid absorption capacity is examined using this plastic limit value (PL value).

Usually, in the granulation process, the liquid speed that can be sprayed with each formulation is approximately proportional to the PL value. Therefore, it is considered that B is also proportional to the PL value of the raw material, and conversion by the PL value is necessary. FIG. 9 (a) is a table showing the liquid speed (g / min) and the eye plate area (cm ² ) for each device scale, and FIG. 9 (b) is per unit PL value calculated based on the table of (a). Is a table showing B values (see FIG. 10 for details of each value). In addition, as a PL value of a known substance, for example, lactose: 0.18 mL / g, corn starch: 0.67 mL / g (excluding equilibrium water of 12% or more), Avicel PH101: 1.23 mL / g (7% or less) ), Powder sugar: 0.23 mL / g, mantle: 0.2 mL / g. In the case of a mixture, the PL value is proportionally distributed based on the mixing ratio.

With such B and C in mind, if the above-mentioned conditions in FIG. 6 are examined again from the viewpoint of B and C, the fluidized bed apparatus 1 according to the present invention performs processing within the following range of B and C values. Is possible. First, regarding the B value, the liquid speed exceeds the standard × 1.5, that is, B per unit PL value (hereinafter referred to as [B]; [B] = B / PL) is 1.3 or more and 3 It is possible to perform processing within a range of 1.2 or less (1.3 ≦ [B] ≦ 3.2). In this case, considering the range in which the time shortening appears more effectively and the liquid speed is standard × 2.0 to 3.0, 1.7 ≦ [B] ≦ 3.2 is more preferable. The C value is preferably more than wind speed (cm / min) × 8.5 × 10 ⁻⁵ kJ / cm ³ and less than or equal to wind speed (cm / min) × 11 × 10 ⁻⁵ kJ / cm ^3. .

  On the other hand, in addition to C and B, the ratio A = B / C is further considered here. This ratio A is dimensionless and indicates the amount of liquid added per amount of heat consumed. This is also considered as a ratio between the amount of liquid added and the drying capacity, and simply indicates how many times the spraying amount is higher than the drying capacity. FIG. 10 is a table in which the processing conditions and the values of C, B, and A are calculated in each of the 30, 60, and 120 type apparatuses when the dew points of the processing gas supplied to the apparatus are 14 ° C. and 6 ° C. is there. FIG. 11 is a graph in which the calculation results of FIG. 10 are plotted, with [B] on the horizontal axis and C on the vertical axis, and the hatched lines in the figure indicate A per unit PL value (hereinafter referred to as [A]). The value of [A] = A / PL). In addition, the value of [B] and [A] uses the standard prescription value (0.33) as the above-mentioned PL value. In this case, the standard formulation is a formula of lactose: corn starch = 7: 3, which is used as a standard formulation for fluidized bed granulation of fine granules.

Therefore, looking at the conventional granulation method from the viewpoint of “A”, in the apparatus of 30 type or more in which the area of the eye plate exceeds 0.1 m ² , the standard minimum air volume used in the initial stage of granulation passes through the eye plate. When the wind speed is 0.4 or more and less than 1.5 m / sec (air volume / eye plate area)
・ B: Less than PL x 1.6 (kJ / min · cm ² ) (Liquid speed = Standard x 1.5: Including the upper limit of standard treatment)
(PL: PL value of raw material)
(See FIG. 9), according to the calculation result of FIG.
A: Less than PL × 6.8. This is the value of the region X in FIG. 11, and the conventional processing condition is that when A ([A]) per unit PL value is approximately “7” when viewed on the basis of “A”. The upper region (less than 6.8).

  Next, when [A] is obtained from the conditions of B and C in the fluidized bed apparatus 1, from 1.3 ≦ [B] ≦ 3.2, 0.24 <[B] ≦ 0.31, 5.4 A condition of ≦ [A] ≦ 10.3 is obtained. This means that a good granulation treatment is possible from the upper limit layer of [A] = 6.8 in the conventional condition in FIG. 11 to the line of [A] = 10 exceeding the upper limit layer. [A] = 8.2 (point P1 in FIG. 11), 9.8 (same as P2), 120 type [A] = 8.5 (same as P3), 10.3 (same as P4) Granulation becomes possible. According to experiments by the inventors, it has been found that when the value of [A] exceeds 11, the raw material is blocked and the particle size distribution varies.

  In this way, when the processing conditions are grasped from the viewpoint of “A” and the conventional machine is compared with the apparatus, the difference between the granulation conditions in the fluidized bed apparatus 1 and the granulation conditions of the conventional machine is understood from FIG. Becomes clear. Further, the condition “A” can be calculated by simply inputting an air volume, a liquid addition amount, and a PL value in the process of initial granulation in a 30-120 type apparatus without considering the apparatus scale. For this reason, it is possible to easily obtain the optimum condition and reduce the processing time without performing complicated condition setting.

It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.
For example, the processing conditions described above are merely examples of conditions applicable to the fluidized bed apparatus 1 of the present invention, and the fluidized bed apparatus of the present invention is not limited to the implementation under the processing conditions. Further, as described above, the fluidized bed apparatus 1 adopts the one-gun side spray method, but the number and arrangement positions of the spray guns are not necessarily limited to the configuration of the embodiment, and a plurality of spray guns are used. It is also possible to place a spray in the casing. Furthermore, the spray casing 6 has a tapered shape so as to form a flow rate suppressing portion on the upper end portion side of the flow chamber. However, if the cross-sectional area on the upper end portion side of the flow chamber is enlarged, the spray casing has a small diameter portion and a large diameter portion. It may be a two-stage shape (or a multi-stage shape of three or more stages) divided into parts. However, it is preferable that the stepped portion itself has a tapered shape so that powder particles do not accumulate on the stepped portion.

DESCRIPTION OF SYMBOLS 1 Fluidized bed apparatus 2 Processing container 3 Support stand 4 Cover unit 5 Filter casing 6 Spray casing 7 Raw material container 8 Air supply unit 11 Cover bracket 12 Exhaust port 13 Lifting mechanism 14 Top plate 15 Cartridge filter 16 Swing bracket 17 Upper end of flow chamber 17a Part 17b Lower end part 18 Side wall part 19 Spray gun 20 Carriage 21 Raw material storage chamber 22 Plate plate 23 Straight part 24 Taper part 25 Slit 25a Opening part 25b Airflow piece 26 Vent hole 27 Air supply chamber 28 Air supply duct Hs Straight part height Q Heat consumption Sa Sauce pan area C Heat consumption per unit pan area Q
B Value of liquid addition per unit pan area converted to calorie A Liquid addition per unit of heat consumed

Claims (9)

An air supply unit having an air supply chamber to which a processing gas is supplied from a gas supply source;
A raw material container that is disposed above the air supply unit and accommodates an object to be processed;
A spray casing which is disposed above the raw material container and in which a fluid chamber in which the object to be treated is suspended and flowed by a processing gas is formed;
A filter casing disposed above the spray casing and disposed with a filter for processing gas filtration,
A flow for granulating the object to be processed by fluidizing the object to be processed accommodated in the raw material container with the processing gas and spraying a liquid to the fluidized object to be processed. A layer device,
The raw material container is arranged at the bottom on the air supply unit side to hold the workpiece, and a columnar straight portion arranged above the eye plate and extending upward with the same diameter. A tapered portion formed in the shape of an inverted truncated cone that is provided above the straight portion and has a large diameter upward.
B (kJ / min · cm ² ), the value obtained by converting the amount of liquid added per unit pan area into heat,
When the PL value indicating the liquid absorption capacity of the workpiece is PL,
The fluidized bed apparatus according to claim 1, wherein B is PL × 1.3 ≦ B ≦ PL × 3.2. The fluidized bed apparatus according to claim 1, wherein
The fluidized bed apparatus according to claim 1, wherein the straight portion has a height Hs of 1/6 to 1/2 of the diameter of the countersink plate. The fluidized bed apparatus according to claim 1 or 2,
A fluidized bed apparatus having a flow velocity suppressing section having a larger cross-sectional area on the upper side of the spray casing than on the lower side. The fluidized bed apparatus according to claim 3,
The fluidized bed apparatus according to claim 1, wherein the spray casing is formed in a tapered shape having an upper side having a larger cross-sectional area than a lower side. In the fluidized-bed apparatus in any one of Claims 1-4,
The eye plate is
A slit that is arranged radially in the plate and generates a swirling airflow of the processing gas above the plate.
A fluidized bed apparatus comprising: a vent hole disposed in a dotted pattern on the eye plate, wherein the processing gas is ejected upward to suppress the formation of the swirling airflow by the slit. In the fluidized-bed apparatus in any one of Claims 1-5,
The fluidized bed apparatus, wherein B is preferably PL × 1.7 ≦ B ≦ PL × 3.2. In the fluidized-bed apparatus in any one of Claims 1-6,
Q is the amount of heat consumed when the process gas passes through the fluidized bed apparatus,
Q (kJ / min) = (Supply temperature-Exhaust temperature) (K) x Airflow (kg / min) x Air specific heat (J / g · K)
When the heat consumption Q per unit dish area is C (= Q / Sa) (kJ / min · cm ² ),
The flow rate is characterized in that C is higher than wind speed (cm / min) × 8.5 × 10 ⁻⁵ kJ / cm ³ and lower than wind speed (cm / min) × 11 × 10 ⁻⁵ kJ / cm ^3. Layer equipment. In the fluidized-bed apparatus in any one of Claims 1-7,
The fluidized bed apparatus is an apparatus in which an area of the countersink plate exceeds 0.1 m ² . In the fluidized-bed apparatus in any one of Claims 1-8,
The fluidized bed apparatus, wherein the PL value is 0.1 or more and 0.5 or less.

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