JP6838916B2 - Fluidized bed drying device - Google Patents

Description

The present invention mainly relates to a fluidized bed drying device that dries powders and granules while flowing them.

Conventionally, as shown in Patent Document 1, a fluidized bed drying device has been known in which powder or granular material is housed in a predetermined container and heated air is sent from the lower part of the container to dry the powder or granular material while flowing it. ing.

The fluidized bed drying device of Patent Document 1 includes a container-shaped dryer main body, and an intake duct and a second intake duct are connected to the dryer main body. The air flowing through the intake duct (primary air) is supplied upward from the lower end of the dryer body. The air (secondary air) flowing through the second intake duct is horizontally supplied from the side surface of the dryer body. Patent Document 1 describes that by supplying secondary air from the second intake duct, the inflow amount of the primary air is relatively reduced, and the drying rate of the powder or granular material is lowered.

Japanese Unexamined Patent Publication No. 53-99562

Patent Document 1 aims to reduce the drying rate in order to suppress the generation rate of gas generated when the powder or granular material is dried. On the other hand, in the fluidized bed drying apparatus, it is required to shorten the drying time of the powder or granular material in order to improve the processing speed. However, since Patent Document 1 aims to reduce the drying rate, Patent Document 1 does not describe a method for shortening the drying time of the powder or granular material.

The present invention has been made in view of the above circumstances, and a main object thereof is to provide a fluidized bed drying apparatus capable of shortening the drying time of powder or granular material.

The problem to be solved by the present invention is as described above, and next, the means for solving this problem and its effect will be described.

According to the viewpoint of the present invention, a fluidized bed drying device having the following configuration is provided. That is, this fluidized bed drying device includes a container unit, a first air supply unit, and a second air supply unit. Powders and granules are housed in the container portion. The first air supply unit causes the powder or granular material to flow by supplying gas upward from the lower part of the container unit. The second air supply unit supplies gas diagonally downward from the side surface of the container unit. The lower part of the container portion includes a tapered portion which is an inverted truncated cone-shaped portion whose diameter increases as it approaches upward, and the powder or granular material flows and circulates in the portion including the tapered portion. The second air supply unit supplies gas from the upper end portion or higher of the tapered portion.

As a result, the powder or granular material wound upward by the gas supplied by the first air supply unit can be forcibly moved downward by the gas supplied by the second air supply unit. As a result, the powder or granular material can be efficiently circulated, so that the drying time of the powder or granular material can be shortened.

According to the present invention, a fluidized bed drying device capable of shortening the drying time of powder or granular material can be realized.

The side sectional view of the fluidized bed drying apparatus which concerns on 1st Embodiment. AA plan sectional view and BB plan sectional view of the fluidized bed drying apparatus. The schematic diagram which compares the flow of the powder or granular material of the prior art and this embodiment. The side sectional view of the fluidized bed drying apparatus which concerns on 2nd Embodiment. The side sectional view of the fluidized bed drying apparatus which concerns on 3rd Embodiment.

Next, an embodiment of the present invention will be described with reference to the drawings. First, the fluidized bed drying apparatus 1 according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a side sectional view of the fluidized bed drying apparatus 1 according to the first embodiment. FIG. 2 is a sectional view taken along the line AA and a sectional view taken along the line BB of the fluidized bed drying apparatus 1 of FIG. In FIG. 1, the flow of gas in the fluidized bed drying device 1 is indicated by a thick arrow, and the flow of powder or granular material in the fluidized bed drying device 1 is indicated by a thin arrow. Further, in the following description, the upstream of the gas flow is simply referred to as an upstream, and the downstream of the gas flow is simply referred to as a downstream.

The fluidized bed drying device 1 is a device that dries the contained powder or granular material 100 while flowing it. As shown in FIG. 1, the fluidized bed drying device 1 includes a container unit 10, a heating unit 20, a first air supply unit 30, a second air supply unit 40, a bug filter 50, an exhaust duct 60, and the like. To be equipped.

The container portion 10 contains the powder or granular material 100 to be dried. As shown in FIG. 1, the container portion 10 includes a tapered portion 11, a cylindrical portion 12, and a perforated plate 13. Further, the container portion 10 is formed with a first supply port 15, a second supply port 16, and a discharge port 17. The container portion 10 is preferably made of metal, but may be made of another material (for example, resin).

The tapered portion 11 constitutes the lower portion of the container portion 10, and is an inverted truncated cone-shaped portion whose diameter increases as it approaches the upper part. A cylindrical portion 12 is located above the tapered portion 11. The cylindrical portion 12 is a cylindrical portion having a constant diameter. The tapered portion 11 and the cylindrical portion 12 are one seamless member, but the tapered portion 11 and the cylindrical portion 12 may be formed of separate members and connected to each other.

The lower end of the tapered portion 11 is open, and this opened portion corresponds to the first supply port 15. The perforated plate 13 is arranged so as to close the first supply port 15. The perforated plate 13 is formed with a large number of minute pores through which gas can pass but through which the powder or granular material 100 cannot pass. The gas for flowing and drying the powder or granular material 100 is supplied through the pores of the perforated plate 13. The perforated plate 13 may be a wire mesh having fine pores formed therein, as long as the gas and the powder or granular material 100 can be separated from each other.

A second supply port 16 for supplying a gas for flowing and drying the powder or granular material 100 is formed at the lower end of the side surface of the cylindrical portion 12. In this embodiment, two second supply ports 16 are formed. As shown in FIG. 2B, the two second supply ports 16 are formed so as to face each other (positions differ by 180 degrees) in a plan view (the arrangement interval of the second supply ports 16 is 180). It may be other than degree). The number of the second supply ports 16 may be one or three or more. Further, by increasing the number of the second supply ports 16, the gas flow in the container portion 10 (particularly, the swirling flow described later) can be made uniform.

The second supply port 16 is a side surface of the cylindrical portion 12 and is formed below the bug filter 50. The vertical position of the second supply port 16 is arbitrary, for example, the upper end of the cylindrical portion 12, the vertical central portion of the cylindrical portion 12, the central portion of the length from the cylindrical portion 12 to the bug filter 50, and the bug. The lower end of the filter 50, the lower end of the cylindrical portion 12, the upper end of the tapered portion 11, the central portion of the tapered portion 11 in the vertical direction, and the like are set as reference heights, and at least one of the upper limit value and the lower limit value is set from these reference heights. It may be formed in the height range represented by selecting.

On the upper surface of the cylindrical portion 12, a discharge port 17 for discharging a gas for flowing and drying the powder or granular material 100 is formed. The discharge port 17 may be formed not on the upper surface of the cylindrical portion 12 but on the upper end portion of the side surface of the cylindrical portion 12.

A duct 21 is connected to the heating unit 20, and gas is supplied from the duct 21. The gas supplied to the duct 21 may be air or a gas other than air. Further, in the fluidized bed drying device 1, gas may be supplied to the heating unit 20 by a suction flow generated by a suction device arranged on the downstream side of the duct 21, or a blower arranged on the upstream side of the duct 21. Gas may be supplied to the heating unit 20 by the delivery flow generated by the apparatus (the same applies to other ducts). The gas supplied to the heating unit 20 is heated by a heater or the like (not shown) included in the heating unit 20.

The first air supply unit 30 includes a first air supply duct 31 and an air supply chamber 32. The first air supply duct 31 is connected to the heating unit 20, and the gas heated by the heating unit 20 flows. The downstream end of the first air supply duct 31 is connected to the side surface of the air supply chamber 32. Gas is supplied to the air supply chamber 32 from the first air supply duct 31, and this gas is supplied to the inside of the container portion 10 via the perforated plate 13.

The second air supply unit 40 includes a second intake duct 41. Unheated gas is flowing through the second intake duct 41. The gas flowing through the second intake duct 41 may be air or a gas other than air. The downstream end of the second intake duct 41 is connected to the second supply port 16 formed in the cylindrical portion 12. As shown in FIG. 1, at least the downstream end of the second intake duct 41 is arranged so as to approach downward as it approaches the second supply port 16. With this configuration, the second air supply unit 40 supplies gas to the container unit 10 diagonally downward. Since the fluidized bed drying device 1 is formed with two second supply ports 16, the same number (that is, two) of the second intake ducts 41 are also arranged. In the present embodiment, the flow rate of the gas supplied by the second air supply unit 40 (the sum of the two second air supply units 40) is smaller than the flow rate of the gas supplied by the first air supply unit 30, but at most. Is also good.

Further, as shown in FIG. 2B, in the second intake duct 41, the virtual line extending in the longitudinal direction of the second intake duct 41 avoids the center of the container portion 10 (outside the center of the container portion 10). It is arranged (to pass through). In particular, in the present embodiment, the second intake duct 41 is arranged so that the virtual line is along the inner wall surface of the container portion 10 (so that it approximates the tangential direction of the inner wall surface of the container portion 10). As a result, as shown in FIG. 2B, a swirling flow can be generated inside the container portion 10. Further, the two second intake ducts 41 are arranged so that the directions of the generated swirling flows are aligned. Specifically, the two second intake ducts 41 are arranged so that a virtual line extending in the longitudinal direction of the second intake duct 41 runs counterclockwise. An adjusting mechanism capable of adjusting the direction of the second intake duct 41 (that is, the direction in which the second flowing gas is supplied) may be provided. This adjustment mechanism may be able to adjust the orientation of the second intake duct 41 in a plan view (FIG. 2), or may be able to adjust the orientation of the second intake duct 41 in a side view (FIG. 1). It may be good, or both may be adjustable. The powder or granular material 100 housed in the container portion 10 is fluidized and dried by the gas supplied by the first air supply unit 30 and the second air supply unit 40.

The bug filter 50 is located inside the container portion 10 and above the container portion 10 (in the present embodiment, above the center of the cylindrical portion 12). The bag filter 50 is a filter that allows gas to pass through and does not allow the powder or granular material 100 to pass through.

The exhaust duct 60 is connected to the exhaust port 17 of the container portion 10. The gas that has passed through the bag filter 50 is discharged from the exhaust duct 60 through the discharge port 17.

Next, the flow of the gas in the container portion 10 and the flow of the powder or granular material 100 will be described. In the following description, the gas supplied by the first air supply unit 30 is referred to as a first fluidized gas, and the gas supplied by the second air supply unit 40 is referred to as a second fluidized gas. Although a complicated gas flow is formed in the container portion 10, the main gas flow will be described below.

The first flowing gas is supplied upward (to include the component in the upward direction) from the lower surface of the tapered portion 11 (specifically, the perforated plate 13). As a result, an upward gas flow is generated in the central portion of the container portion 10 (the portion corresponding to the upper side of the perforated plate 13). Further, the first fluidized gas passes through the bag filter 50 and is discharged from the discharge port 17.

The second flowing gas is supplied obliquely downward from the side surface of the cylindrical portion 12. Further, the second fluidized gas is supplied so as to generate a swirling flow that swirls outside the central portion of the container portion 10 (near the inner wall surface of the container portion 10). The second flowing gas flows downward while swirling along the vicinity of the inner wall surface of the container portion 10. After that, it merges with the first flowing gas, goes upward, passes through the bag filter 50, and is discharged from the discharge port 17.

Next, the flow of the powder or granular material 100 in the container portion 10 will be described. Although a complicated flow of the powder or granular material 100 is configured in the container portion 10, the main flow of the powder or granular material 100 will be described below. The powder or granular material 100 housed in the container portion 10 stays in the lower part of the tapered portion 11 until the first fluidized gas is supplied. By supplying the first fluidized gas, the powder or granular material 100 is wound upward by the first fluidized gas.

The powder or granular material 100 is wound upward to some extent and then flowed toward the inner wall surface of the container portion 10 as shown in FIG. 2A. After that, as shown in FIG. 2B, the powder or granular material 100 is influenced by the second fluidized gas and is swirled downward.

By causing the powder or granular material 100 to flow downward by the second fluidized gas, the powder or granular material 100 wound up by the first fluidized gas can be dropped downward in a short time. As a result, the powder or granular material 100 can be efficiently circulated, so that the drying time of the powder or granular material 100 can be shortened. In particular, in the present embodiment, since the first fluidized gas is heated, the powder or granular material 100 can be wound up again by the high temperature first fluidized gas, so that the drying time of the powder or granular material 100 can be further shortened.

Further, since the powder or granular material 100 is swirled by the second fluidized gas, the powder or granular material 100 receives a force toward the inner wall surface due to the centrifugal force of the swirling flow. As a result, the powder or granular material 100 wound up by the first fluidized gas easily moves to the outside, so that the same powder or granular material 100 is unlikely to remain floating upward. Therefore, by swirling the powder or granular material 100 with the second fluidized gas, the powder or granular material 100 can be easily circulated, so that the drying time can be shortened while preventing uneven drying of the powder or granular material 100.

As described above, in order to shorten the drying time, it is necessary to constantly generate the first fluidized gas and the second fluidized gas. Therefore, the first air supply unit 30 and the second air supply unit 40 always supply the first fluidized gas and the second fluidized gas to the container portion 10 without being intermittent during drying.

Next, the flow of the powder or granular material 100 of the fluidized bed drying device 1 of the present embodiment described above is compared with the flow of the powder or granular material of the conventional fluidized bed drying device having no second air supply unit 40. To do. FIG. 3 is a schematic diagram comparing the flow of the powder or granular material of the conventional example and the present embodiment.

As shown in FIG. 3, in the conventional fluidized bed drying apparatus, since the second fluidized gas is not supplied, the powder or granular material cannot be forcibly flowed downward. In the conventional fluidized bed drying device, the powder or granular material falls mainly due to its own weight. Therefore, it takes time for the powder or granular material wound up by the first fluidized gas to be wound up again, and the drying time becomes longer as compared with the present embodiment.

Further, in the conventional example, since the swirling flow is not generated, it is difficult for the powder or granular material to flow to the inner peripheral surface of the container portion. Therefore, a situation occurs in which the powder or granular material wound up by the first fluidized gas does not fall and remains floating upward. This causes uneven drying. Further, since the powder or granular material is difficult to circulate, the drying time becomes longer as compared with the present embodiment.

As described above, by providing the second air supply unit 40 of the present embodiment, the drying time of the powder or granular material 100 can be significantly shortened.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a side sectional view of the fluidized bed drying apparatus 1 according to the second embodiment. The same reference numerals are given to the drawings for the same or similar configurations as those in the first embodiment, and the description thereof will be omitted.

In the first embodiment, the second fluidized gas supplied by the second air supply unit 40 was not heated by the heating unit 20. On the other hand, in the second embodiment, the second common duct 43 branches from the first air supply duct 31 downstream of the heating unit 20. The second common duct 43 is further branched into a number corresponding to the second supply port 16 (two in the second embodiment), and the second intake duct 41, which is a duct after the branch, is the respective second supply port 16. Connected to. With this configuration, not only the first fluidized gas but also the second fluidized gas can be heated to a high temperature, so that the drying time can be further shortened.

In the second embodiment, the first fluidized gas and the second fluidized gas are heated by the same heating unit 20, but the heating unit that heats the first fluidized gas and the heating that heats the second fluidized gas. The part may be different. In this configuration, it is not necessary to connect the first air supply duct 31 and the second common duct 43.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 5 is a side sectional view of the fluidized bed drying apparatus 1 according to the third embodiment. The same reference numerals are given to the drawings for the same or similar configurations as those in the first embodiment, and the description thereof will be omitted.

In the first embodiment, the first air supply unit 30 and the second air supply unit 40 do not have a damper for adjusting the flow rate through which the gas passes per unit time (hereinafter, simply the flow rate). On the other hand, in the third embodiment, the first air supply unit 30 and the second air supply unit 40 are provided with a first damper 35 and a second damper 45 for adjusting the flow rate, respectively.

The first damper 35 can adjust the flow rate of the gas from the first air supply duct 31 toward the air supply chamber 32. The second damper 45 can adjust the flow rate of gas from the second common duct 43 to the second intake duct 41. The position where the first damper 35 and the second damper 45 are arranged is arbitrary, and may be arranged in another duct. The first damper 35 and the second damper 45 can be controlled by a control unit (not shown) included in the fluidized bed drying device 1.

Here, the optimum value of the flow rates of the first fluidized gas and the second fluidized gas differs depending on the powder or granular material 100. For example, when the powder or granular material 100 is light, the powder or granular material 100 is likely to be rolled up by the first fluidized gas, so that it is necessary to increase the flow rate of the second fluidized gas to strengthen the downward gas flow. On the other hand, when the powder or granular material 100 is heavy, it is difficult for the powder or granular material 100 to wind up upward, so it is necessary to increase the flow rate of the first fluidized gas to sufficiently wind up the powder or granular material 100.

In the third embodiment, the flow rate of the first fluid gas (opening of the first damper 35), the flow rate of the second fluid gas (opening of the second damper 45), and the flow rate of the first fluid gas are controlled by the operator. The flow rate (flow rate ratio, damper opening ratio) of the second flowing gas with respect to the flow rate can be adjusted. Alternatively, the operator inputs the physical property values (type, density, etc.) of the powder or granular material 100, and the control unit of the fluidized bed drying device 1 obtains the optimum value of the opening degree of the first damper 35 and the second damper 45. , The opening degree of the first damper 35 and the second damper 45 may be changed to the optimum value. According to the configuration of the third embodiment, the flow rate of the first fluidized gas and the flow rate of the second fluidized gas can be adjusted to values that match the powder or granular material 100, so that the drying time can be further shortened.

As described above, the fluidized bed drying device 1 of the above embodiment includes a container unit 10, a first air supply unit 30, and a second air supply unit 40. The powder or granular material 100 is housed in the container portion 10. The first air supply unit 30 causes the powder or granular material 100 to flow by supplying the first fluidized gas upward from the lower part of the container unit 10. The second air supply unit 40 supplies the second fluidized gas diagonally downward from the side surface of the container unit 10.

As a result, the powder or granular material 100 wound upward by the first fluidized gas can be forcibly moved downward by the second fluidized gas. As a result, the powder or granular material 100 can be efficiently circulated, so that the drying time of the powder or granular material 100 can be shortened.

In the fluidized bed drying device 1 of the above embodiment, the second air supply unit 40 rotates in the plan view by supplying the second fluidized gas toward a position avoiding the center of the container unit 10 in the plan view. Generate a swirling flow.

As a result, the powder or granular material 100 wound upward by the first fluidized gas easily flies toward the inner wall surface of the container portion 10 due to the centrifugal force of the swirling flow. As a result, it becomes easy to form a flow in which the powder or granular material 100 flows from the bottom to the top in the center of the container portion 10 and flows from the top to the bottom on the inner wall surface of the container portion 10, so that the powder or granular material 100 circulates. It becomes easier, and the drying time can be further shortened while preventing uneven drying.

A plurality of second air supply units 40 are formed in the fluidized bed drying device 1 of the above embodiment. Each second air supply unit 40 supplies gas so that the directions of the generated swirling flows are aligned.

As a result, a swirling flow is likely to occur, so that the powder or granular material 100 is more easily circulated, and the drying time can be further shortened while further preventing uneven drying.

In the fluidized bed drying apparatus 1 of the above embodiment, at least one of the first air supply unit 30 and the second air supply unit 40 supplies the heated gas to the container unit 10.

As a result, the temperature of the gas flowing in the container portion 10 rises, so that the drying time can be further shortened.

In the fluidized bed drying device 1 of the above embodiment, the container portion 10 includes a tapered portion 11 and a cylindrical portion 12. The tapered portion 11 has an inverted truncated cone shape in which the diameter increases as it approaches the upper side. The cylindrical portion 12 is located above the tapered portion 11 and has a cylindrical shape having a constant diameter. The second air supply unit 40 supplies the second fluidized gas to the container unit 10 from the second supply port 16 formed on the side surface of the cylindrical unit 12.

Although the preferred embodiment of the present invention has been described above, the above configuration can be changed as follows, for example.

The shape of the container portion 10 described in the above embodiment is an example, and may have a different shape. For example, a cylindrical member may be further connected below the tapered portion 11.

The first air supply unit 30 described in the above embodiment is configured to supply the heated first fluidized gas, but may be configured to supply the unheated first fluidized gas. Therefore, the fluidized bed drying device 1 may have a configuration in which both the first fluidized gas and the second fluidized gas are not heated, or the first fluidized gas is not heated and the second fluidized gas is heated. It may be the configuration that is used.

In the second embodiment, the fluidized bed drying device 1 having a configuration in which the first air supply duct 31 and the second common duct 43 are connected in order to make the heating unit 20 common has been disclosed, but the duct 21 and the second common duct 43 have been disclosed. Can also be configured to connect. In this configuration, the second fluidized gas is not heated, but the duct provided in the fluidized bed drying device 1 can be simplified.

In the third embodiment, a configuration including the first damper 35 and the second damper 45 is disclosed in a configuration in which a part of the ducts of the first air supply unit 30 and the second air supply unit 40 is not shared, but the second embodiment is disclosed. In a configuration in which a part of the ducts of the first air supply unit 30 and the second air supply unit 40 is common as in the embodiment, at least one of the first damper 35 and the second damper 45 may be provided.

In the above embodiment, the present invention is applied to the fluidized bed drying device 1 for drying the powder or granular material 100, but the present invention is applied to the fluidized bed granulation drying device for drying and granulating the powder or granular material. You can also. For example, the present invention can be applied to a fluidized bed granulation drying device having a structure including a spray nozzle for injecting a liquid for granulation onto a powder or granular material.

1 Fluidized bed drying device 10 Container part 11 Tapered part 12 Cylindrical part 20 Heating part 30 1st air supply part 31 1st air supply duct 40 2nd air supply part 41 2nd intake duct 100 Powder particles

Claims (4)

The container where the powder and granules are stored and
A first air supply unit that allows the powder or granular material to flow by supplying gas upward from the lower part of the container unit, and
A second air supply unit that supplies gas diagonally downward from the side surface of the container unit,
Equipped with a,
The lower portion of the container portion includes a tapered portion which is an inverted truncated cone-shaped portion whose diameter increases as it approaches upward, and the powder or granular material flows and circulates in the portion including the tapered portion.
The second air supply unit is a fluidized bed drying device, characterized in that gas is supplied from the upper end portion or higher of the tapered portion. The fluidized bed drying apparatus according to claim 1.
The second air supply unit supplies a gas toward a position avoiding the center of the container unit in a plan view to generate a swirling flow in the plan view. .. The fluidized bed drying apparatus according to claim 2.
A plurality of the second air supply sections are formed, and the second air supply section is formed.
Each of the second air supply units is a fluidized bed drying device, characterized in that gas is supplied so that the directions of the generated swirling flows are aligned. The fluidized bed drying apparatus according to any one of claims 1 to 3.
A fluidized bed drying device, wherein at least one of the first air supply unit and the second air supply unit supplies a heated gas to the container unit.

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