JP5950533B2 - Fluidized bed equipment - Google Patents

Description

  The present invention relates to a fluidized bed apparatus that performs processing by spraying powder with a gas and dispersing the powder in the gas.

  The fluidized bed apparatus is widely used for the purpose of mixing, granulating, coating, drying and the like in the industry handling powders such as pharmaceuticals or foods. When combustible powder such as medicine or food is handled in the processing container of the fluidized bed apparatus, the powder may be scattered to form a dust cloud in the processing container. In addition, when handling the droplets by spraying a flammable liquid component in the processing container, a mist of the liquid component may be generated from the droplets, and a mist cloud may be formed. It is desirable that the electric field generated inside such a dust cloud or mist cloud be small. Specifically, it is desirable to manage such that the diameter of the charged cloud does not exceed 0.7 m (page 89 of Non-Patent Document 1).

  In order to reduce the electric field generated in the dust cloud or the mist cloud, the charge amount of the dust constituting the dust cloud or the mist constituting the mist cloud may be reduced. Antistatic methods for powders include reducing the resistivity of powders by humidification, addition of polar solvents, etc., selecting materials that take into account the charge train, limiting the handling scale and speed, converting to large particle size powders, It is known to suppress the generation of static electricity by preventing the generation and scattering of dust, and to eliminate static electricity with a static eliminator (page 292 of Non-Patent Document 2). In addition, as a method for preventing mist from being charged, it is known to use a discharge nozzle that has a shape that prevents discharge and ejection at high pressure as much as possible and that makes it difficult to atomize (page 292 of Non-Patent Document 2). .

National Institute of Occupational Safety and Health, “Technical Guidelines for Occupational Safety and Health Research Static Electricity Safety Guidelines 2007”, Japan Industrial Safety Technology Association, June 1, 2007 The Electrostatics Society, "New Edition Electrostatic Handbook", 1st Edition, Ohm Co., Ltd., November 25, 1998 Senichi Masuda, “Recent Electrostatic Engineering”, High Pressure Gas Safety Association, July 1974

  However, there are powders that cannot be handled under high relative humidity. Further, if the relative humidity at the time of handling and the kind and content of the solvent are restricted, for example, the powder cannot be dried in the processing container.

  From the viewpoint of the charge train, it is not preferable to manufacture the processing container with a material that is less likely to generate static electricity with respect to the powder, because there are restrictions on the material of the processing container.

  Further, when the amount of powder to be processed is limited, a problem arises that the production capacity is limited.

  Regarding the particle size of the powder, especially in the pharmaceutical industry, in order to obtain the effect of the product, it is often handled in a fine powder state in the processing container, and conversion to a large particle size powder is often difficult.

  In addition, in the processing container of the fluidized bed apparatus, the powder is spouted and scattered to perform granulation or drying, and thus preventing the generation of dust clouds in the processing container or preventing the powder from scattering, difficult.

  When the static eliminator is installed in the container, there is a problem that the cost increases.

  In addition, it is not easy to give restrictions on the method of discharging and ejecting the granulating liquid sprayed for granulation in the processing container and the shape of the discharging nozzle because of restrictions on operation and equipment.

  The present invention has been made in view of the above-described problems, and its purpose is to maintain a small electric field generated in the processing container even when a charged dust cloud is formed in the processing container, while maintaining a small combustible powder. It is to realize a fluidized bed apparatus that can handle the body.

  The fluidized bed apparatus according to the present invention includes a processing container and a dispersion plate disposed at the bottom of the processing container, and feeds gas from the dispersion plate into the processing container, whereby powder in the processing container is obtained. Is a fluidized bed apparatus in which the powder is dispersed in a space where the powder in the upper part of the processing container is not deposited, and the powder flows into the gas in the processing container. In order to solve the above problem, one or more partition plates arranged in the processing container and dividing the space in which the powder is dispersed into a plurality of spaces arranged in a horizontal direction are provided, and the partition plates are electrically conductive. It is characterized by having sex. The processing container and the partition plate are electrically grounded.

  According to the above configuration, since the partition plate having conductivity divides the space in which the powder in the processing container is dispersed, the spatial charge cloud formed by charging the dispersed powder is spatially expanded. The partition plate cuts off the electric field that increases accordingly. Therefore, the electric field strength on the wall surface of the processing container can be reduced. Therefore, generation | occurrence | production of an ignitable electrostatic discharge can be suppressed. Therefore, the volume of the processing container can be increased and the processing capacity of the fluidized bed apparatus can be improved. Further, since the partition plate divides the space in which the powder is dispersed into a plurality of spaces arranged in the horizontal direction, the powder hardly adheres to the partition plate and does not hinder the flow of the powder.

  The fluidized bed apparatus may include a plurality of the partition plates arranged radially in the processing container.

  According to said structure, since the several partition plate is arrange | positioned radially, the space in which the powder in a processing container disperse | distributes can be divided | segmented efficiently. In addition, the radially arranged partition plates do not hinder the movement of the powder in the outer direction in the divided space, so that the occurrence of ignitable electrostatic discharge is suppressed and the powder is allowed to flow effectively. Can do.

  The fluidized bed apparatus also includes a plurality of the partition plates and a horizontal space in the processing container so as to divide the space in which the powder in the upper part in the processing container is dispersed into an inner space and an outer space. A cylindrical partition plate that is arranged in the center in the direction and that is open at the top and bottom, the cylindrical partition plate has conductivity, and the plurality of partition plates include a sidewall of the processing container and the cylindrical partition plate The space outside the cylindrical partition plate may be divided into a plurality of spaces arranged in the horizontal direction.

  According to the above configuration, since the cylindrical partition plate is arranged at the center in the processing container, there is no object that obstructs the upward and downward flow of the powder in the central region at the top of the processing container, and the powder is effectively used. Can be made to flow. Moreover, adhesion of the powder to the cylindrical partition plate and the partition plate can be suppressed. Moreover, since the cylindrical partition plate divides the space in which the powder in the processing container is dispersed into an inner space and an outer space, the occurrence of ignitable electrostatic discharge can be suppressed.

  The plurality of partition plates may be arranged radially around the cylindrical partition plate.

  According to said structure, the partition plate arrange | positioned radially can divide | segment the space outside a cylindrical partition plate efficiently.

  The plurality of partition plates may further extend to a space above the cylindrical partition plate, and may be configured to divide the space above the cylindrical partition plate into a plurality of spaces arranged in a horizontal direction. .

  According to said structure, the powder which rose in the cylindrical partition plate is disperse | distributed to each space divided | segmented by the partition plate. Therefore, the space above the cylindrical partition plate can be efficiently divided without hindering the flow of the powder.

  Further, the maximum horizontal width inside the processing container is larger than 0.7 m, and the diameter of the largest virtual sphere inscribed in the space divided by the partition plate does not exceed 0.7 m. You may comprise so that a partition plate may be arrange | positioned.

  According to the above configuration, as described in Non-Patent Document 1 (page 89), “In order to prevent brush discharge from a charged cloud, the scale of the charged cloud does not exceed 0.7 m in diameter, or the charged cloud. The processing container can be enlarged while substantially satisfying at least one of the indicators that the average electric field within the range does not exceed 1 kV / cm. Therefore, it is possible to suppress the occurrence of ignitable electrostatic discharge and improve the processing capability of the fluidized bed apparatus.

  Further, the fluidized bed apparatus may be configured to include one or more spray nozzles corresponding to the divided spaces.

  According to said structure, since a binder liquid etc. can be injected to powder from a spray nozzle, the granulation process of powder can be performed efficiently. In addition, the electric field strength in the space where the projection such as the spray nozzle is present can be reduced.

  The fluidized bed apparatus includes a draft tube that is disposed above the dispersion plate at a predetermined distance from the dispersion plate and is open at the top and bottom, and the cylindrical partition plate is disposed above the draft tube. It is good also as a structure located in.

  According to the above configuration, the powder that has risen in the draft tube rises mainly through the cylindrical partition plate, so that the flow of the powder is not hindered, and the upper space in the processing container Can be divided to suppress the occurrence of ignitable electrostatic discharge.

Further, the fluidized bed apparatus may handle combustible powder having a volume resistivity of 10 ⁸ Ω · m or more.

According to the above configuration, even when powder particles having a volume resistivity of 10 ⁸ Ω · m or more and easily charged are dispersed, the electric field strength can be reduced and the powder can be processed.

  Further, the processing container includes an upper container constituting the upper part of the processing container and a lower container constituting the lower part of the processing container, and the upper container includes the partition plate as a first partition plate, The lower container includes the dispersion plate, and is detachable from the upper container in order to put the powder into the processing container. The lower container is arranged in a horizontal direction in the space in the lower container. The structure provided with the 2nd partition plate divided | segmented into a some space may be sufficient.

  According to said structure, the 2nd partition plate is also arrange | positioned inside the detachable lower container. Therefore, it is possible to reduce the electric field strength inside the lower container where the density of the powder tends to increase.

  Moreover, the structure which divides | segments the space in the said processing container similarly may be sufficient as a said 1st partition plate and a said 2nd partition plate when planarly viewed.

  According to said structure, the electric field strength inside a processing container can be reduced, without inhibiting the flow of powder.

  The first partition plate and the second partition plate may be electrically connected so as to have the same potential.

  Further, the lower end of the second partition plate may be configured to be separated from the dispersion plate and positioned below the powder surface of the powder to be deposited.

  According to said structure, the electric field strength in the space where powder disperses (it is a gaseous phase) can be reduced more effectively.

  The fluidized bed apparatus according to the present invention includes a processing container and a dispersion plate disposed at the bottom of the processing container, and feeds gas from the dispersion plate into the processing container, whereby powder in the processing container is obtained. Is a fluidized bed apparatus in which the powder is dispersed in a space where the powder in the upper part of the processing container is not deposited, and the powder flows in a gas. In order to achieve this, a partition plate that is arranged in the processing container and divides the space in which the powder is dispersed into a plurality of spaces arranged in a horizontal direction is provided, and the partition plate has conductivity. .

  Therefore, the electric field strength on the wall surface of the processing container can be reduced, and the occurrence of ignitable electrostatic discharge can be suppressed. Therefore, the volume of the processing container can be increased and the processing capacity of the fluidized bed apparatus can be improved.

It is a model front sectional view showing the composition of the fluidized bed device in one embodiment concerning the present invention. It is sectional drawing which shows the structure of the fluidized bed apparatus seen from the cutting line AA of FIG. It is a model front sectional view showing the composition of the fluid bed apparatus in other embodiments concerning the present invention. It is a typical perspective view which shows the structure of the partition of the said fluidized bed apparatus. It is sectional drawing which shows the structure of the fluidized bed apparatus seen from the cutting line BB of FIG. (A) is a schematic front sectional view showing a configuration of a fluidized bed apparatus according to another embodiment of the present invention, and (b) is a sectional view taken along a cutting line DD shown in (a). is there. (A) is a figure which shows the other one form of a process container and a partition, (b) is sectional drawing seen from the cutting line EE shown to (a). (A) is a figure which shows another form of a process container and a partition, (b) is sectional drawing seen from the cutting line FF shown to (a). It is a figure which shows another form of a process container and a partition. It is a model front view which shows the structure of the fluidized-bed apparatus of one Example which concerns on this invention. It is a figure which shows what divided the space inside the processing container of the said fluidized bed apparatus into the some tetrahedron in simulation. It is a figure which shows the cross-sectional location of the said processing container. It is a figure which shows the simulation result of the electric field strength distribution in the said processing container, and is a figure which shows the electric field strength distribution in the cross section A shown in FIG. It is a figure which shows the simulation result of the electric field strength distribution in the said processing container, and is a figure which shows the electric field strength distribution in the cross section B shown in FIG. It is a figure which shows the simulation result of the electric field strength distribution in the said processing container, and is a figure which shows the electric field strength distribution in the cross section C shown in FIG. It is a figure which shows the simulation result of the electric field strength distribution of the conventional fluidized bed apparatus which does not provide a partition, and is a figure which shows the electric field strength distribution in the cross section corresponding to the cross section A shown in FIG. It is a figure which shows the simulation result of the electric field strength distribution of the conventional fluidized bed apparatus which does not provide a partition, and is a figure which shows the electric field strength distribution in the cross section corresponding to the cross section B shown in FIG. It is a figure which shows the simulation result of the electric field strength distribution of the conventional fluidized bed apparatus which does not provide a partition, and is a figure which shows the electric field strength distribution in the cross section corresponding to the cross section C shown in FIG. It is a model front sectional view showing the composition of the fluid bed apparatus in other embodiments concerning the present invention. (A) is sectional drawing which shows the structure of the fluidized bed apparatus seen from the cutting line GG of FIG. 19, (b) is the structure of the fluidized bed apparatus seen from the cutting line HH of FIG. It is sectional drawing shown. FIG. 20 is a schematic front sectional view showing a state where the lower container of the fluidized bed apparatus shown in FIG. 19 is slid. It is a model front sectional view showing the composition of the fluidized bed device in other one form concerning the present invention.

  A fluidized bed apparatus (a spouted bed type fluidized bed apparatus), for example, flows gas from the center of the lower part of the processing vessel, blows up powder (solid particles), circulates the dispersed powder in the upper part of the processing vessel, It is a device that makes contact between powder and gas. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Embodiment 1]
FIG. 1 is a schematic front sectional view showing the configuration of the fluidized bed apparatus in the present embodiment. The fluidized bed apparatus 1 includes a cylindrical processing container 2 having a lower conical shape at the bottom, a disc-shaped dispersion plate 3 disposed at the bottom of the processing container 2, and a substantially cylindrical disposed below the dispersion plate 3. And a cylindrical exhaust unit 5 disposed on the processing vessel 2. The processing container 2 includes a take-out portion 6 that can be separated from the processing container 2 by sliding in the lateral direction at the lower part thereof. The take-out unit 6 slides integrally with the air blowing unit 4. The dispersion plate 3 has holes with a fine diameter that does not allow powder to pass therethrough, and allows gas to pass therethrough.

  The fluidized bed apparatus 1 of the present embodiment is a batch processing type fluidized bed apparatus that can perform a plurality of processes such as granulation, coating, and drying of powder in a single processing vessel 2. In addition, only one of the treatments can be performed on the powder. The powder to be processed is put into the slide take-out unit 6 and supplied into the processing container 2. Note that the powder to be processed may be transported into the processing container 2 by pneumatic transportation.

  In the powder drying process, gas (in this case, dry air) is sent from the outside to the blower 4 through the air inlet 7, and gas is sent into the processing container 2 through the dispersion plate 3. The gas sent into the processing container 2 blows up the powder deposited on the dispersion plate 3 and disperses the powder throughout the space in the processing container 2. As a result, the powder in the processing container 2 is spouted into a gas and processed (drying process) while flowing through the entire processing container 2. In addition, the sent-in gas rises and is exhausted to the outside of the fluidized bed apparatus 1 from the exhaust port 8 provided in the upper part of the exhaust part 5. A bag filter 9 is provided in the lower part of the exhaust part 5 so that the powder in the processing container 2 is not discharged to the outside together with the gas. A cartridge type filter may be used instead of the bag filter. Further, the bag filter or the cartridge type filter is of a conductive type, and is preferably used with grounding. Thus, the fluidized bed apparatus 1 causes the powder to flow in the entire gas in the processing container (processing chamber) 2 and dry the powder.

  In the granulation step of the powder, a binder liquid is added to the powder in a fluid state to bond the powders together to generate granules and the like. The fluidized bed apparatus 1 includes a plurality of sprays (spray nozzles) 10 for injecting a binder liquid or the like into the processing container 2. Similarly, in the powder coating process, a coating layer can be formed on the granules by adding a binder liquid or the like to the granules in a fluid state. In addition, when using a fluidized bed apparatus only for mixing or drying of a powder, it is not necessary to provide a spray.

  Further, the fluidized bed apparatus 1 includes a conductive partition plate 11 in a cylindrical region at the top of the processing vessel 2. The partition plate 11 is electrically connected so as to have the same potential as that of the conductive processing container 2 and is grounded. The partition plate 11 partitions an upper space in the processing container 2 in which the powder is dispersed. The space in which the powder in the upper part in the processing container 2 is dispersed means a space in which the powder is dispersed and flows in the gas in the space below the bag filter 9 and above the dispersion plate 3. When depositing on the dispersion plate 3, the space where the powder is deposited is not included.

  FIG. 2 is a cross-sectional view showing the configuration of the fluidized bed apparatus 1 as viewed from the cutting line AA in FIG. The partition plate 11 is radially arranged from substantially the center so as to equally divide the space inside the processing container 2 into four spaces arranged in the horizontal direction. Moreover, the spray 10 is provided so as to correspond to each divided space.

  Each space divided by the partition plate 11 is connected on the upper side and the lower side of the partition plate 11. The powder (or granules, etc.) spouted by the gas sent into the processing container 2 from the dispersion plate 3 (see FIG. 1) is dispersed in each space divided by the partition plate 11, and the lowered powder is It is blown up by the gas again and flows in the entire processing container 2.

By the way, examples of ignitable electrostatic discharge generated from dust clouds include brush discharge and streamer discharge. According to page 23 of Non-Patent Document 1, brush discharge occurs when the surface charge density of a charged object is 3 μC / m ² or more and the surface electric field is 5 kV / cm or more. Further, on page 48 of Non-Patent Document 3, as a condition for generating a streamer discharge, (1) an average of about 2.7 to 5 kV / cm or more along an assumed discharge path as a streamer traveling condition. It describes that there is an electric field strength and (2) that the electric field breakdown strength of air exists as a trigger in at least one location of the discharge path as a discharge starting condition. That is, in order to prevent ignitable electrostatic discharge, it is necessary to suppress the magnitude of the generated electric field to a predetermined value or less.

  In addition, in the document “Safety Engineering” (editor: Safety Engineering Association, August 15, 1996, Vol. 35, No. 4 (1996), p. 292), there is a space charge in a sphere of radius r. The calculation method of the electric field when it is uniformly distributed is described (calculated from the following formula (1)).

This equation means that if the radius r is small, that is, if the size of the generated charged cloud can be suppressed to be small, the magnitude of the electric field in the space can also be suppressed.

  The fluidized bed apparatus 1 of the present embodiment includes a conductive partition plate 11 in an upper space where the powder inside the processing container 2 is dispersed. Since the partition plate 11 divides the space above the processing container 2 (blocks the electric field in the space), the spread of the space charge cloud formed by the powder in the horizontal direction can be limited. When the space of the processing container 2 is divided, a virtual sphere having a predetermined size (for example, a diameter of 0.7 m) can be arranged (that is, the largest virtual sphere inscribed in the processing container and the partition plate). The partition plate 11 is arranged to reduce the space so that the diameter is less than the above size. Therefore, the electric field in the vicinity of the wall surface of the processing container 2 can be kept small, and the possibility that ignitable electrostatic discharge occurs can be reduced. Therefore, by arranging the partition plate 11 in the processing container 2 having an inner diameter (inner maximum width) larger than the size, the electric field in the vicinity of the wall surface of the processing container 2 can be suppressed, and ignitable electrostatic discharge can occur. Can be reduced. Therefore, the processing capacity of the fluidized bed apparatus 1 can be improved by increasing the volume of the processing vessel 2 while suppressing the occurrence of ignitable electrostatic discharge.

  Non-Patent Document 1 (page 89) describes that it is desirable to manage the charged cloud so that the diameter of the scale does not exceed 0.7 m. Therefore, the fluidized bed apparatus 1 of the present embodiment is particularly effective when the diameter of the charged cloud (dust etc.) formed in the processing container 2 exceeds 0.7 m. That is, when the horizontal minimum width inside the processing container 2 exceeds 0.7 m, the partition plate 11 divides the space inside the processing container 2, and the horizontal minimum width of the divided space is set to 0. By setting the length to 7 m or less, the scale of the charged cloud formed in the processing container 2 can be reduced, and the electric field generated in the space can be reduced.

Further, when the volume resistivity of the particles constituting the dust is 10 ⁸ Ω · m or more (see page 56 of Non-Patent Document 1), there is a possibility that the particles are largely charged. If a charged particle cloud is present inside the processing container, the space charge density increases and the electric field strength also increases. Therefore, since the possibility of generating ignitable electrostatic discharge increases, it is desirable to further reduce the electric field in the space in order to reduce the possibility. Therefore, when handling such powder, the fluidized bed apparatus 1 of this Embodiment can be used especially suitably.

  In this embodiment, the space is efficiently divided by arranging the four partition plates 11 radially from the center. In particular, when the powder flows so as to move up the central part of the processing container 2 and descend near the wall surface of the processing container 2, the radially arranged partition plates 11 have a diameter in the upper space in the processing container 2. Since the movement of the powder in the direction is not hindered, the occurrence of ignitable electrostatic discharge can be suppressed and the powder can be effectively flowed.

  Further, in order to minimize the collision with the flowing powder so as not to hinder the flow of the powder, the cylindrical processing container 2 has the cylindrical axis arranged in parallel to the vertical direction, and the partition plate 11. Are preferably arranged parallel to the vertical direction. Further, the shape of each partition plate 11 is preferably a flat surface in order to minimize the adhesion of powder. Further, the thickness of the partition plate 11 is not particularly limited, but is preferably thinner in order to reduce the adhesion of the powder to the partition plate 11, for example, 5 mm or less, and more preferably 3 mm or less. The material of the partition plate 11 is not particularly limited as long as the partition plate 11 is conductive. For example, a metal SUS304 or the like, a conductive resin, a cloth woven with conductive fibers, or a cloth containing conductive fibers ( (Including non-woven fabric). For example, when a metal such as SUS304 is used for the partition plate 11, the surface of the partition plate 11 is a smooth surface that has been subjected to buffing or electrolytic polishing in order to minimize adhesion of powder and improve cleaning properties. A surface is preferred. Note that the partition plate may have a hole as long as the partition plate is configured so that a virtual sphere of a predetermined size cannot be disposed in the processing container. The shape of the processing container is not limited to a cylindrical shape, and may be a cylindrical container having a polygonal cross section.

  In addition, when a protrusion is present in a space where charged combustible dust is present, the electric field strength in the space that affects the occurrence of ignitable electrostatic discharge around the protrusion increases. Therefore, in order to reduce the electric field strength around the protrusion, the partition plate may be arranged so as to divide the space at the height where the protrusion exists. Examples of such protrusions include a spray installed on the wall surface of the container, a meter such as a thermometer or a powder level meter, or a protective tube for protecting the meter.

  The partition plate 11 is not limited to a flat plate, and may have a curved surface such as a corrugated plate.

[Embodiment 2]
Next, the fluidized bed apparatus of Embodiment 2 will be described. For convenience of explanation, members / configurations having the same functions as those in the drawings described in the first embodiment are given the same reference numerals, and detailed descriptions thereof are omitted.

  FIG. 3 is a schematic front sectional view showing the configuration of the fluidized bed apparatus in the present embodiment. The fluidized bed apparatus 13 includes a cylindrical processing container 14 whose lower part has an inverted conical shape, a dispersion plate 15 disposed at the bottom of the processing container 14, a blower unit 16 disposed under the dispersion plate 15, and The exhaust part 5 arrange | positioned on the processing container 14 is provided. The dispersion plate 15 has holes with a fine diameter that does not allow powder to pass therethrough, and allows gas to pass therethrough. Further, the dispersion plate 15 has more holes in the central portion than in the peripheral portion, and allows more gas to pass through in the central portion.

  The fluidized bed apparatus 13 is a Wurster type fluidized bed apparatus including a draft tube 17. The draft tube 17 has a cylindrical shape in which the inner diameter of the lower end opening is larger than the inner diameter of the upper end opening. The draft tube 17 is arranged at the center in the horizontal direction of the processing container 14 so that the lower end opening thereof is opposed to the dispersion plate 15 with a predetermined distance. The draft tube 17 is fixed and grounded by a support member (not shown) connected to the processing container 14. The fluidized bed apparatus 13 includes a spray 18 that ejects a binder liquid or the like. The spray 18 is configured to inject a binder liquid or the like upward into the draft tube 17, and supplies the binder liquid or the like to the gas and powder rising in the draft tube 17.

  Thereby, the gas sent into the blower 16 is mainly ejected from the center of the dispersion plate 15, passes through the draft tube 17, and is ejected to the upper part of the processing container 14. The powder deposited on the dispersion plate 15 is blown up by the gas rising under the draft tube 17, passes through the draft tube 17, and is dispersed in the space above the processing container 14. The sprayed powder descends along the vicinity of the wall surface of the processing vessel 14 where the rising airflow is weak. In this manner, the powder flows through the entire processing container 14 and processing such as drying of the powder or generation of granules is performed.

  The fluidized bed apparatus 13 according to the present embodiment includes a conductive partition 19 at the top of the processing container 14. The partition 19 is configured by combining a conductive cylindrical partition plate (cylindrical partition plate) 20 and a conductive flat partition plate 21. FIG. 4 is a schematic perspective view showing the configuration of the partition 19. The partition plate 21 is a flat plate partially cut out in an arch shape. The partition 19 is composed of a cylindrical partition plate 20 that is arranged at the center and is open at the top and bottom, and three partition plates 21 that are uniformly distributed radially around the partition plate 20.

  FIG. 5 is a cross-sectional view showing the configuration of the fluidized bed device 13 as seen from the section line BB in FIG. The three partition plates 21 are arranged radially from the center so as to equally divide the space inside the processing container 14 into three spaces arranged in the horizontal direction. A cylindrical partition plate 20 is disposed in the center of the processing container 14 in the horizontal direction.

  The spaces divided by the partition plates 20 and 21 are connected on the upper and lower sides of the partition plates 20 and 21. As shown in FIG. 3, the gas sent from the dispersion plate 15 into the processing container 14 blows up the powder deposited on the dispersion plate 15 and rises mainly through the draft tube 17. The gas and powder rising through the draft tube 17 mainly pass through the cylindrical partition plate 20 disposed at the center of the upper portion of the processing vessel 14, and the upper end opening of the cylindrical partition plate 20. The powder dispersed in the spaces divided by the three partition plates 21 (arrow 70) and descending along the wall surface of the processing vessel 14 (arrow 71) is dispersed in the region outside the draft tube 17. The powder deposited on the plate 15 is re-sprayed by the gas rising in the draft tube 17 (arrow 72), and circulates and flows so as to convect the whole of the processing container 14.

  The fluidized bed apparatus 13 of the present embodiment is a Wurster type fluidized bed apparatus that includes a draft tube 17 and in which powder and gas rise mainly in the center. Therefore, when the partition plate 11 arranged radially as shown in FIGS. 1 and 2 is disposed, the lower end portion of the partition plate 11 obstructs the flow of powder and gas, and the powder is applied to the partition plate 11. It becomes easy to adhere. Therefore, the fluidized bed apparatus 13 includes a cylindrical partition plate 20 above the draft tube 17, and efficiently divides the space so as not to hinder the flow of powder and gas. Therefore, the fluidized bed apparatus 13 can increase the capacity of the processing container 14 by suppressing the occurrence of ignitable electrostatic discharge, and can effectively flow the powder, thereby improving the processing capacity. To.

  Although the draft tube 17 is also a cylindrical conductor, the draft tube 17 is disposed below the processing container 14 where the powder is deposited in order to spout the powder at the center of the processing container 14. . The draft tube 17 has an effect of suppressing the occurrence of ignitable electrostatic discharge. However, for example, in the configuration in which the draft tube 17 is extended to the upper part of the processing container 14 which is a space in which mainly the powder is dispersed (for example, to the upper end of the partition plate 21 shown in FIG. 3), the powder in the processing container 14 The flow of the liquid is hindered, resulting in problems such as the inability to produce granules of a desired size or shape. The partition plate of the fluidized bed apparatus of the present invention is configured to prevent the occurrence of ignitable electrostatic discharge in the space where the powder is dispersed without inhibiting the powder flow.

[Embodiment 3]
Next, a fluidized bed apparatus according to Embodiment 3 will be described. For convenience of explanation, members / configurations having the same functions as those in the drawings described in the first embodiment are given the same reference numerals, and detailed descriptions thereof are omitted.

  FIG. 6A is a schematic front sectional view showing a processing container and a partition of the fluidized bed apparatus in the present embodiment, and FIG. 6B is a cross-sectional view taken along the line DD shown in FIG. FIG. 6 (a) and 6 (b), the blower unit and the exhaust unit having the same configuration as in the first embodiment are omitted, and the processing container 30 and the partition 31 are illustrated, and FIG. 6 (a). In FIG. 2, the internal structure is drawn partially through the processing container. The processing container 30 is a container whose lower part is an inverted conical shape and whose upper part is a cylindrical shape. The partition 31 provided in the cylindrical region of the processing vessel 30 has the same shape as the partition 19 shown in FIG. 4, and includes a conductive cylindrical partition plate (tubular partition plate) 32 and three conductive layers. And a flat partition plate 33 having the same characteristics. The partition plate 33 is a flat plate partially cut out in an arch shape. As shown in FIG. 6B, a cylindrical partition plate 32 is arranged at the center in the processing container 30, and three partition plates 33 are arranged radially and evenly therearound. Further, the configuration shown in FIG. 6A is the same as the configuration of the second embodiment (FIG. 3) in that a spray 34 for injecting a binder liquid or the like is disposed downward on the upper end opening of the partition plate 32. Different. An arrow shown in FIG. 6A represents a flow in which the powder flows. In addition, the cylindrical partition plate arrange | positioned in the center in a processing container is not restricted to a cylindrical shape, A polygonal cylindrical partition plate may be sufficient.

[Other forms of partitions]
Next, the form of the fluidized bed apparatus provided with another partition is demonstrated. For convenience of explanation, detailed description of members and configurations having the same functions as those in the drawings described in the first embodiment will be omitted.

  Fig.7 (a) is a figure which shows another form of a processing container and a partition, and FIG.7 (b) is sectional drawing seen from the cutting line EE shown to Fig.7 (a). 7 (a) and 7 (b), the air blower and the exhaust, which are the same as those in the first embodiment, are omitted, and the processing container 35 and the partition plate 36 are illustrated, and FIG. ) Shows the internal structure partially through the processing vessel. The processing container 35 has the same shape as the processing container 30 shown in FIG. As shown in FIG. 7B, the three conductive partition plates 36 provided in the cylindrical region of the processing container 35 are arranged radially from the center of the processing container 35, and the space above the processing container 35. Are equally divided into three spaces. Further, sprays 37 for injecting a binder liquid or the like are disposed downward in three divided spaces arranged in the horizontal direction. Thereby, in any divided space, since the binder liquid or the like can be sprayed onto the powder, the powder can be efficiently granulated. An arrow shown in FIG. 7A represents a flow in which the powder flows.

  FIG. 8A is a view showing another embodiment of the processing container and the partition, and FIG. 8B is a cross-sectional view seen from the cutting line F shown in FIG. 8 (a) and 8 (b), the blower unit and the exhaust unit having the same configuration as in the first embodiment are omitted, and the processing container 38 and the partition 39 are illustrated, and FIG. 8 (a). In FIG. 2, the internal structure is drawn partially through the processing container. The processing container 38 has the same shape as the processing container 30 shown in FIG. The partition 39 is configured by combining a conductive cylindrical partition plate (tubular partition plate) 40 and two conductive flat partition plates 41. As shown in FIG. 8B, a cylindrical partition plate 40 is disposed in the center of the processing container 38, and two partition plates 41 are connected to the partition plate 40 and the side wall of the processing container 38 around the partition plate 40. In this manner, the cylindrical partition plates 40 are arranged radially with an angle of 180 degrees. A space is divided in the radial direction of the processing container 38 by the partition plate 40, and a space outside the partition plate 40 is divided by the partition plate 41. An arrow shown in FIG. 8A represents a flow in which the powder flows. In addition, the cylindrical partition plate arrange | positioned in the center in a processing container is not restricted to a cylindrical shape, A polygonal cylindrical partition plate may be sufficient.

  Further, as a modification of the first embodiment, instead of the flat partition plates 11 arranged radially as shown in FIG. 2, curved partition plates 42 as shown in FIG. You may arrange. FIG. 9 is a view showing another embodiment of the processing container and the partition.

  Alternatively, five or more flat partition plates may be arranged in the vertical direction in a radial manner with respect to the cylindrical processing container, and the processing container may be divided into a plurality of spaces. Moreover, you may divide | segment the space in a processing container unevenly by several partition plates. In addition, the conductive partition plate and the wall surface of the processing container do not need to be in contact with each other without a gap, and are connected so as to be at the same potential, and substantially divide the space in the processing container, There is no problem even if a slight gap is provided.

[Embodiment 4]
Next, the fluidized bed apparatus of Embodiment 4 is demonstrated. For convenience of explanation, members / configurations having the same functions as those in the drawings described in the first embodiment are given the same reference numerals, and detailed descriptions thereof are omitted.

  FIG. 19 is a schematic front sectional view showing the configuration of the fluidized bed apparatus in the present embodiment. The arrow shown in FIG. 19 represents the flow through which the powder flows.

  The fluidized bed apparatus 60 includes a processing container 61, a disc-shaped dispersion plate 3 disposed at the bottom of the processing container 61, a substantially cylindrical air blowing unit 4 disposed below the dispersion plate 3, and the processing container 61. A cylindrical exhaust portion 5 is provided above. The processing container 61 includes a cylindrical upper container 61 a that forms the upper part of the processing container 61, and a conical lower container (extraction unit) 61 b that forms the lower part of the processing container 61. The conductive upper container 61a and the lower container 61b are electrically connected so as to have the same potential and are grounded. The fluidized bed apparatus 60 includes a plurality of sprays (spray nozzles) 63 for injecting a binder liquid or the like into the processing container 61.

  The upper container 61a includes a conductive upper partition plate (first partition plate) 62a. The upper partition plate 62a is electrically connected so as to have the same potential as that of the conductive upper container 61a, and is grounded. The upper partition plate 62a partitions the space in the upper container 61a where the powder is dispersed.

  The lower container 61b is a conical container having a small lower diameter, and includes a dispersion plate 3 at the bottom. The lower container 61b includes a conductive lower partition plate (second partition plate) 62b. As shown in FIG. 21, the lower container 61b is slidable in the horizontal direction and detachable from the upper container 61a. With the lower container 61b removed from the upper container 61a, the powder to be processed is placed in the lower container 61b. Can be charged or removed. Note that the lower container 61b may not be completely separated, and may be connected to the upper container 61a by a hinge or the like. In order to slide the lower container 61b, a gap may be provided between the upper partition plate 62a and the lower partition plate 62b.

  The lower partition plate 62b is disposed to be separated from the dispersion plate 3, and partitions the space in the lower container 61b. In order to reduce the electric field strength in the space in which the powder is dispersed (in the gas phase), the lower end of the lower partition plate 62b can be placed below the powder level of the deposited powder. In addition, the lower end of the lower partition plate 62b may be located above the powder surface. The lower partition plate 62b is electrically connected so as to have the same potential as that of the conductive lower container 61b, and is grounded. That is, the upper container 61a, the lower container 61b, the upper partition plate 62a, and the lower partition plate 62b are electrically connected so as to have the same potential and are grounded.

  FIG. 20A is a cross-sectional view showing the configuration of the fluidized bed apparatus 60 as seen from the cutting line GG in FIG. The upper partition plate 62a is arranged radially from substantially the center so as to equally divide the space inside the upper container 61a into three spaces arranged in the horizontal direction. The spray 63 is provided so as to correspond to each divided space. Thereby, in any divided space, since the binder liquid or the like can be sprayed onto the powder, the powder can be efficiently granulated.

  FIG. 20B is a cross-sectional view showing the configuration of the fluidized bed apparatus 60 as seen from the cutting line HH in FIG. The lower partition plate 62b has the same shape as the upper partition plate 62a in plan view. The lower partition plate 62b is arranged radially from substantially the center so as to equally divide the space inside the lower container 61b into three spaces arranged in the horizontal direction in the same manner as the space inside the upper container 61a. When viewed in plan, the upper partition plate 62a and the lower partition plate 62b divide the space in the processing container 61 in the same manner. That is, the upper partition plate 62a and the lower partition plate 62b are arranged so as to be aligned in order to minimize the collision with the flowing powder so as not to hinder the flow of the powder.

  The spaces divided by the upper partition plate 62a and the lower partition plate 62b are connected on the upper side of the upper partition plate 62a and the lower side of the lower partition plate 62b. The powder (or granules, etc.) spouted by the gas fed into the processing container 61 from the dispersion plate 3 (see FIG. 19) is dispersed in each space divided by the upper partition plate 62a and the lower partition plate 62b. The lowered powder is again blown up by the gas and flows in the entire processing container 61.

  As in this embodiment, by providing the lower partition plate 62b also in the space of the lower container 61b that needs to be attached and detached for the introduction of the powder to be processed, the maximum electric field strength in the processing container can be lowered. it can. The charged powder flows throughout the processing container 61, but the lower the powder density, the higher the density of the powder. Therefore, the lower partition plate 62b provided in the lower container 61b works effectively to reduce the maximum electric field strength in the processing container. In order to allow the lower container 61b to slide, the lower partition plate 62b is provided separately from the upper partition plate 62a disposed inside the upper container 61a.

  In addition, as shown in FIG. 22, you may comprise a fluidized-bed apparatus so that the lower end of the lower partition plate 62b may be located in the upper surface of the dispersion plate 3. As shown in FIG.

  An embodiment of the fluidized bed apparatus of the present invention will be described below. The fluidized bed apparatus of the present example has the same configuration as that of the fluidized bed apparatus described in the third embodiment (FIG. 6).

  FIG. 10 is a schematic front view showing the configuration of the fluidized bed apparatus of the present embodiment, FIG. 10 (a) is a plan view seen from the top of the fluidized bed apparatus, and FIG. 10 (b) is a fluidized bed apparatus. It is a model front sectional drawing of an apparatus. 10 (a) and 10 (b), the blower unit and the exhaust unit having the same configuration as in the first embodiment are omitted, the processing container 51 and the partition 52 are illustrated, and the processing container and the like are partially illustrated. It is transparent and depicts the internal structure.

  The fluidized bed apparatus 50 includes a processing container 51 and a partition 52 disposed inside the processing container 51. The processing vessel 51 is a vessel having a lower conical shape at the bottom and a cylindrical shape at the top. The partition 52 has the same shape as the partition 31 shown in FIG. 6, and is composed of a cylindrical partition plate (tubular partition plate) 53 and three partition plates partially cut out in an arch shape. 54 were combined. Further, a spray 55 is disposed in the arch-shaped cutout portions of the three partition plates 54. Note that the processing container 51, the partition 52, and the spray 55 have conductivity and are grounded.

  The height H1 of the processing vessel 51 is 1420 mm, the height H2 of the cylindrical portion of the processing vessel 51 is 900 mm, the height H3 of the frustoconical portion of the processing vessel 51 is 520 mm, and the maximum inner diameter W1 of the upper portion of the processing vessel 51 Is 1500 mm, and the minimum inner diameter W2 of the lower portion of the processing vessel 51 is 1100 mm. The height of the partition 52 and the partition plate 54 is 900 mm which is the same as the height H2 of the processing vessel 51, and the length H4 of the portion where the three partition plates 54 are joined at the center is 350 mm. Moreover, the height H5 of the cylindrical partition plate 53 is 400 mm, and the diameter W3 is 600 mm. The diameter W4 of the spray 55 is 60 mm, the height H8 of the cylindrical upper part is 60 mm, the height H9 of the hemispherical lower part is 30 mm, and the distance H7 between the upper end of the spray 55 and the upper end of the processing vessel 51 is 390 mm. is there. The shape of the partition 52 is designed so that a virtual sphere exceeding 0.7 m in diameter cannot be arranged in the space inside the processing container 51.

<Simulation results>
The fluidized bed apparatus 50 was simulated to investigate the internal electric field strength. The simulation result will be described below. In this simulation, the space inside the processing container 51 of the fluidized bed apparatus 50 is virtually divided into a plurality of tetrahedrons, and ANSYS (registered trademark) (Release 12.0) of finite element method multiphysics analysis software is used. This was done by calculating the electrostatic field.

  FIG. 11 is a diagram illustrating a virtual space obtained by dividing the space inside the processing container 51 into a plurality of tetrahedrons in the simulation. The calculation of the electric field strength was performed by calculating the following formula (2) (Poisson's formula) for each minute finite element.

Here, it is assumed that the concentration of the powder in the processing container 51 is 2.19 kg / m ³ , the charged charge amount of the powder is 1.0 × 10 ⁻⁸ C / g, and the space charge density ρ is 2.19 ×. 10 ⁻⁵ C / m ³ was set. It is assumed that the concentration distribution of the powder and the charged charge amount of each powder are uniform. In addition, the relative dielectric constant of the space was set to 1.0, and the potential was set to 0 V on the assumption that the conductor in the processing container 51 was grounded.

  FIG. 12 is a view showing a cross-sectional portion of the processing container. Section A is a vertical section passing through the central axis of the processing vessel, section B is a horizontal section passing through the upper end of the spray, and section C is a horizontal section passing through the curved portion below the spray.

  13 to 15 are diagrams showing simulation results of the electric field strength distribution in the processing container 51. FIG. In FIG. 13 to FIG. 15, the intensity of the electric field at each position in the space in the processing container 51 is shown in light and dark (black and white). 13 to 15, a bright position indicates that the electric field intensity is small and a dark position indicates that the electric field intensity is large. The lower bar in the figure indicates the correspondence between the brightness and the electric field intensity. The unit of the numerical value is V / m. is there. 13 is a diagram showing the electric field strength distribution in the cross section A shown in FIG. 12, FIG. 14 is a diagram showing the electric field strength distribution in the cross section B shown in FIG. 12, and FIG. It is a figure showing electric field strength distribution in section C shown.

  According to this simulation result, the electric field strength showed the maximum value in the downward curved portion of the spray 55 shown in FIG. 15, and the value was 21 kV / cm. Since the maximum value of the electric field strength does not exceed the dielectric breakdown electric field strength of 30 kV / cm, it is considered that the possibility of occurrence of ignitable electrostatic discharge (streamer discharge) is low.

  On the other hand, the same simulation was performed in the conventional fluidized bed apparatus in which the partition 52 was removed from the fluidized bed apparatus 50 shown in FIG. FIGS. 16-18 is a figure which shows the simulation result of the electric field strength distribution in the conventional fluidized bed apparatus which does not provide a partition. 16 is a diagram showing the electric field strength distribution in the cross section corresponding to the cross section A shown in FIG. 12, and FIG. 17 is a diagram showing the electric field strength distribution in the cross section corresponding to the cross section B shown in FIG. 18 is a diagram showing an electric field strength distribution in a cross section corresponding to the cross section C shown in FIG.

  The simulation conditions are the same as the simulation conditions shown in FIGS. Also in FIGS. 16 to 18, as in FIGS. 13 to 15, the intensity of the electric field at each position in the space is shown in light and dark. As shown in FIGS. 16-18, in the fluidized bed apparatus without a partition, the area | region with a large electric field strength is increasing. Further, the electric field strength showed the maximum value at the upper end portion of the spray 55, and the maximum value of the electric field strength was 97 kV / cm. Since the maximum value of the electric field strength greatly exceeds the dielectric breakdown electric field strength of 30 kV / cm, the fluidized bed apparatus without a partition is ignitable as compared with the fluidized bed apparatus 50 provided with the partition 52 (see FIG. 10). It is considered that electrostatic discharge (streamer discharge) is likely to occur. Moreover, as shown in FIGS. 16-18, in the fluidized bed apparatus without a partition, the electric field strength area | region where an electric field is 2.7 kV / cm or more is increasing. Therefore, in a fluidized bed apparatus without a partition, streamer discharge may be more easily extended than a fluidized bed apparatus provided with a partition.

  As can be seen from the above simulation results, by providing a conductive partition in the region where the powder of the fluidized bed apparatus is dispersed, the electric field strength in the processing vessel is reduced and the possibility of occurrence of ignitable electrostatic discharge is reduced. Can be reduced.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  INDUSTRIAL APPLICABILITY The present invention can be used for a fluidized bed apparatus for processing powders such as pharmaceuticals or foods.

DESCRIPTION OF SYMBOLS 1, 13, 50, 60 Fluidized bed apparatus 2, 14, 30, 35, 38, 51, 61 Processing container 3, 15 Dispersing plate 4, 16 Blower part 5 Exhaust part 6 Extraction part 7 Intake port 8 Exhaust port 9 Bag filter 10, 18, 34, 37, 55, 63 Spray (spray nozzle)
11, 21, 33, 36, 41, 42, 54 Partition plate 20, 32, 40, 53 Partition plate (tubular partition plate)
17 Draft tube 19, 31, 39, 52 Partition (partition plate)
61a Upper container 61b Lower container 62a Upper partition plate (first partition plate)
62b Lower partition plate (second partition plate)

Claims (8)

A processing container that performs mixing, granulation, coating, or drying processing, and a dispersion plate disposed at the bottom of the processing container, and by feeding gas from the dispersion plate into the processing container, the processing container and blown up flammable powder within, by dispersing the powder in a space that is not the powder at the top of the processing container is deposited, by flowing the powder in a gas in the processing container A fluidized bed apparatus for performing the above processing,
A cylindrical partition that is disposed in the center in the horizontal direction in the processing container and is open at the top and bottom so as to divide the space in which the powder in the upper part in the processing container is dispersed into an inner space and an outer space. The board,
A plurality of partition plates arranged in the processing container and dividing the space in which the powder is dispersed into a plurality of spaces arranged in a horizontal direction;
The plurality of partition plates are arranged radially around the cylindrical partition plate so as to connect a side wall of the processing vessel and a side surface of the cylindrical partition plate, and a space outside the cylindrical partition plate is formed. Divide into multiple horizontal spaces,
The plurality of partition plates further extend into a space above the cylindrical partition plate, are connected to each other in the space above the cylindrical partition plate, and pass through the space above the cylindrical partition plate. Divide into multiple horizontal spaces,
The fluidized bed apparatus, wherein the plurality of partition plates and the cylindrical partition plate have conductivity. A processing container that performs mixing, granulation, coating, or drying processing, and a dispersion plate disposed at the bottom of the processing container, and by feeding gas from the dispersion plate into the processing container, the processing container and blown up flammable powder within, by dispersing the powder in a space that is not the powder at the top of the processing container is deposited, by flowing the powder in a gas in the processing container A fluidized bed apparatus for performing the above processing,
A cylindrical partition that is disposed in the center in the horizontal direction in the processing container and is open at the top and bottom so as to divide the space in which the powder in the upper part in the processing container is dispersed into an inner space and an outer space. The board,
A plurality of partition plates arranged in the processing container and dividing the space in which the powder is dispersed into a plurality of spaces arranged in a horizontal direction;
A draft tube that is disposed above the dispersion plate at a predetermined distance from the dispersion plate and is open at the top and bottom,
The cylindrical partition plate is located above the draft tube,
The plurality of partition plates are arranged so as to connect a side wall of the processing vessel and a side surface of the cylindrical partition plate, and divide a space outside the cylindrical partition plate into a plurality of spaces arranged in a horizontal direction,
The fluidized bed apparatus, wherein the plurality of partition plates and the cylindrical partition plate have conductivity. A processing container that performs mixing, granulation, coating, or drying processing, and a dispersion plate disposed at the bottom of the processing container, and by feeding gas from the dispersion plate into the processing container, the processing container and blown up flammable powder within, by dispersing the powder in a space that is not the powder at the top of the processing container is deposited, by flowing the powder in a gas in the processing container A fluidized bed apparatus for performing the above processing,
The processing container includes an upper container constituting the upper part of the processing container, and a lower container constituting the lower part of the processing container,
The upper container includes one or more first partition plates arranged in the upper container and dividing the space in which the powder is dispersed into a plurality of spaces arranged in a horizontal direction,
The lower container includes the dispersion plate, and is detachable from the upper container in order to put the powder into the processing container,
The lower container includes a second partition plate disposed above the dispersion plate, which divides the space in the lower container into a plurality of spaces arranged in a horizontal direction,
The fluidized bed apparatus, wherein the first partition plate has conductivity. 4. The fluidized bed apparatus according to claim 3 , wherein the first partition plate and the second partition plate divide the space in the processing container in the same manner when viewed in a plan view. The second partition plate has conductivity,
The fluidized bed apparatus according to claim 3 or 4 , wherein the first partition plate and the second partition plate are electrically connected to have the same potential. The lower end of the second partition plate is spaced apart from the distribution plate, from claim 3, characterized in that located below the powder level in the powder is deposited according to any one of the 5 Fluidized bed equipment. The fluidized bed apparatus according to any one of claims 1 to 6 , further comprising one or more spray nozzles that correspond to the divided spaces and inject a liquid onto the powder. The fluidized bed apparatus according to any one of claims 1 to 7 , wherein a combustible powder having a volume resistivity of 10 ⁸ Ω · m or more is handled.