JP2013195011A - Drying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the clogging of a heat exchanger by dried objects while suppressing an increase of a gas flow rate.SOLUTION: A drying device 1 includes an airflow conveying pathway 13 for conveying a dried object A by an airflow, and an airflow-type drier 15 for drying the dried object A conveyed by the airflow through the airflow conveying pathway 13 by a heat exchanger 16. The airflow conveying pathway 13 is provided with a classifying means 30 for classifying the dried object A.

Description

  The present invention relates to a drying apparatus for introducing a material from a stirrer to a heat exchanger by airflow conveyance.

  As a drying device for drying wet materials such as sludge, a stirrer to which the material to be dried is supplied from a feeder, an air flow type dryer for drying the material to be dried conveyed from the stirrer, and an air flow type dryer A solid-gas separation means (cyclone) that separates the dried product from the air stream and circulates a part of the dried product separated by the solid-gas separation means to the feeder as a dry product for moisture adjustment, It is known to discharge out of the system as a processed dry matter.

  Moreover, in patent document 1, the conveyance path | route which goes to a solid-gas separation means from an airflow type dryer was branched into the circulation path | route which circulates a dried material to a supply machine, and the discharge path which discharges | emits a dried material out of the system. A drying apparatus is disclosed. According to this drying apparatus, the capacity of each solid-gas separation means can be reduced, and the overall height of the apparatus can be made compact.

JP 2010-210162 A

  Most of the material to be dried discharged from the stirrer is conveyed in a state of being made fine in the stirrer. However, the object to be transported is slightly mixed with a relatively large lump due to moisture contained in the object to be dried.

  On the other hand, a heat exchanger having a large number of heat radiating plates is usually provided in an air-flow dryer in which an object to be dried is conveyed in air. Therefore, when the to-be-dried material conveyed to the airflow type dryer is relatively large, there is a problem that the to-be-dried material is clogged in the gap between the heat radiating plates of the heat exchanger.

  In addition, since the heat exchanger is hot, once the object to be dried is clogged, the heat exchanger is burnt and the removal becomes difficult.

  In order to prevent clogging of the object to be dried, it is conceivable to increase the interval between the heat sinks in the heat exchanger. In such a case, in order to ensure a gas flow rate capable of air-conveying the object to be dried, Gas flow is required.

  This invention is made | formed in view of such a point, The place made into the objective is to prevent clogging of the heat exchanger by to-be-dried material, suppressing the increase in the gas flow rate in a drying apparatus.

  In order to achieve the above object, according to the present invention, a classifying means for classifying an object to be dried is provided in the airflow conveyance path.

  Specifically, the first invention includes an air current conveying path for air conveying an object to be dried and a heat exchanger, and an air current for drying the object to be dried which is air conveyed by the air current conveying path by the heat exchanger. It is intended for a drying apparatus equipped with a type dryer. And the said airflow conveyance path is provided with the classification means which classifies the said to-be-dried object.

  According to the present invention, the material to be dried conveyed in the airflow conveyance path is classified by the classification means before reaching the heat exchanger of the airflow dryer, thereby preventing the heat exchanger from being clogged with the material to be dried. It becomes possible to do.

  A second invention is characterized in that, in the first invention, the classifying means has an enlarged-diameter portion having an inner diameter larger than that of a duct constituting the airflow conveyance path.

  According to this invention, the gas flow velocity in the enlarged diameter portion is lower than the gas flow velocity in the airflow conveyance path on the upstream side of the enlarged diameter portion. Therefore, since the airflow conveying force of the material to be dried is smaller than that on the upstream side in the diameter-enlarged portion, the material to be dried that requires a relatively large conveying force is not air-flowed from the diameter-enlarged portion to the airflow dryer. As a result, the material to be dried can be classified.

  A third invention is characterized in that, in the first or second invention, the classification means is provided with a crushing means for crushing the classified material to be dried.

  According to the present invention, since the classified relatively large to-be-dried object can be crushed small, the crushed to-be-dried object can also be conveyed by airflow to the airflow dryer.

  A fourth invention is characterized in that, in the third invention, the classification means has a retention part in which the classified material to be dried is retained, and the retention part is provided with the crushing means. And

  According to the present invention, the classified material to be dried once stays in the staying portion. Since the staying portion is provided with a crushing means, the stayed material to be dried is crushed into small pieces and then conveyed to the airflow dryer.

  In a fifth aspect based on the second aspect, an inlet for introducing the material to be dried is formed in the lower portion of the enlarged diameter portion, and the material to be dried is formed in the upper portion of the enlarged diameter portion. A discharge port for discharging is formed.

  In a sixth aspect based on the second aspect, an inlet for introducing the material to be dried is formed in a side portion of the enlarged diameter portion, and the material to be dried is formed on an upper portion of the enlarged diameter portion. It is characterized in that a discharge port for discharging the water is formed.

  According to these inventions, the material to be dried is introduced by airflow conveyance from the introduction port formed in the lower part or the side part of the enlarged diameter part. Of the materials to be dried introduced into the enlarged diameter portion, those to be dried that require a relatively large conveying force fall downward. On the other hand, an object to be dried that does not require a relatively large conveying force is conveyed upward and discharged from a discharge port. Therefore, the material to be dried can be classified with a simple configuration.

  According to the present invention, since the classifying means for classifying the object to be dried is provided in the air flow conveyance path, it is possible to prevent the heat exchanger from being clogged with the object to be dried while suppressing an increase in the gas flow rate in the drying apparatus. it can.

FIG. 1 is a schematic configuration diagram illustrating a drying apparatus according to the first embodiment. FIG. 2 is an enlarged longitudinal sectional view showing the configuration of the enlarged diameter portion in the first embodiment. FIG. 3 is an enlarged cross-sectional view showing the configuration of the enlarged diameter portion in the first embodiment. FIG. 4 is an enlarged longitudinal sectional view showing the configuration of the enlarged diameter portion in the second embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiment.

Embodiment 1 of the Invention
1 to 3 show Embodiment 1 of the present invention.

  FIG. 1 is a schematic configuration diagram illustrating a drying apparatus according to the first embodiment. FIG. 2 is an enlarged longitudinal sectional view showing the configuration of the enlarged diameter portion. FIG. 3 is an enlarged cross-sectional view showing the configuration of the enlarged diameter portion.

  The drying apparatus 1 is an apparatus for drying an object to be dried A which is a wet material such as sludge, and as shown in FIG. 1, as shown in FIG. 1, a feeder 11, a stirrer 12, first and second air flow conveying paths 13, 14, an air flow dryer 15, a circulation cyclone 17 and a discharge cyclone 18 that are solid-gas separation means, and a circulation fan 19.

  The supply machine 11 is configured to convey the supplied material A to be dried and to supply it to the stirrer 12 while stirring.

  The stirrer 12 is disposed below the supply unit 11 and has a twin screw 21 for stirring the material A to be dried supplied from the supply unit 11. The stirrer 12 is connected to a duct 22 to which the high temperature gas C is supplied from the circulation fan 19, and to a duct 23 to which the moisture adjusting dried material B <b> 1 is supplied from the circulation cyclone 17. Then, the stirrer 12 agitates the material A to be dried together with the moisture-adjusting dried material B1 and the high-temperature gas C, and conveys the moisture while adjusting the moisture.

  A lower end of the first air flow conveyance path 13 configured by a duct extending in the vertical direction is connected to the downstream side of the agitator 12 in the conveyance direction. And the to-be-dried object A in which the water | moisture content was adjusted with the stirrer 12 is supplied to the 1st airflow conveyance path 13 with the high temperature gas C. As shown in FIG. In the first air flow conveyance path 13, the material A to be dried is air-carryed together with the high temperature gas C.

  The upper end, which is the downstream side of the first airflow conveyance path 13, is connected to the lower end of the airflow dryer 15 that extends in the vertical direction. The airflow dryer 15 has a heat exchanger 16 in which a plurality of heat radiating plates are formed at predetermined intervals. The heat exchanger 16 in this embodiment is a plate-type heat exchanger 16 in which the heat radiating plate is a plate. And the to-be-dried material A is dried with the heat exchanger 16 by distribute | circulating the to-be-dried material A to rise among several plates. As a result, the dried material A to be dried becomes dried materials B1 and B2.

  One end of a second airflow conveyance path 14 made of a duct is connected to the upper end of the airflow dryer 15. The other end side of the second airflow conveying path 14 is branched and connected to the circulation cyclone 17 and the discharge cyclone 18. Then, the moisture-adjusted dried product B1 which is a part of the dried products B1 and B2 dried by the airflow dryer 15 is introduced into the circulation cyclone 17 together with the high temperature gas C, while the dried products B1 and B2 Of these, the processed dry matter B2, which is a portion other than the moisture adjusting dry matter B1, is introduced into the discharge cyclone 18 together with the high temperature gas C.

  The discharge cyclone 18 is configured to separate the processed dry matter B2 and the hot gas C from each other. The separated dried product B2 separated is carried out as a product, while the separated hot gas C is sucked into the circulation fan 19.

  The circulation cyclone 17 is disposed above the stirrer 12 and is configured to separate the moisture adjusting dried material B1 and the high temperature gas C from each other. Then, the separated dried B1 for moisture adjustment is supplied to the lower stirrer 12 through the duct 23, while the separated hot gas C is sucked into the circulation fan 19.

  The circulation fan 19 sucks the hot gas C discharged from the circulation cyclone 17 and the discharge cyclone 18 and supplies a part thereof to the bag filter 25, while supplying the remaining hot gas C to the stirrer 12 through the duct 22. It is configured to supply.

  The hot gas C supplied to the bag filter 25 is supplied to the deodorizing furnace 28 through the condenser 26 and the fan 27. The gas deodorized in the deodorizing furnace 28 is supplied to the airflow dryer 15. A part of the hot gas C in the airflow dryer 15 is exhausted.

  As a main feature of the present invention, the first airflow conveyance path 13 is provided with a classifying means 30 for classifying the material A to be dried. The classifying means 30 is configured to classify the object to be dried A so that the object to be dried A ′ larger than the interval between the plurality of plates in the heat exchanger 16 is not conveyed to the airflow dryer 15.

  As shown in FIG. 2, the classifying means 30 has an enlarged diameter portion 32 having a larger inner diameter than the duct 31 that constitutes the first airflow conveyance path 13. As shown in FIG. 3, the duct 31 and the enlarged diameter portion 32 each have, for example, a square opening cross section. The area of the opening cross section of the enlarged diameter portion 32 is larger than the area of the opening cross section of the duct 31. Therefore, the gas flow velocity in the enlarged diameter portion 32 is lower than the gas flow velocity in the duct 31 of the first airflow conveyance path 13. Then, among the objects to be dried A that are air-conveyed in the first air current conveying path 13, the object to be dried A 'that is larger than the interval between the plates is dropped downward, and the object to be dried that is smaller than the interval between the plates. The material to be dried A is classified by air-conveying a upward.

  An inlet 33 through which the material to be dried A is introduced is formed at the lower part of the enlarged diameter portion 32, while an outlet 34 for discharging the material to be dried a is formed at the upper part of the enlarged diameter portion 32. Yes.

  An inclined surface 35 is formed on the upper inner wall surface around the discharge port 34 in the enlarged diameter portion 32 so that the inner diameter gradually decreases upward. Further, an inclined surface 36 is formed on the lower inner wall surface around the inlet 33 in the enlarged diameter portion 32 so that the inner diameter gradually decreases downward. The inclined surface 36 serves as a retaining portion 37 that retains an object A ′ to be dried that is larger than the interval between the plurality of classified plates.

  The staying part 37 is provided with a crushing means 40 for crushing a relatively large material A ′ to be dried. As shown in FIG. 3, the crushing means 40 includes, for example, a disk-shaped rotating plate 38 that is provided on the inclined surface 36 and rotates, and a crushing blade 39 that is provided on the surface of the rotating plate 38. It is constituted by means. A plurality of crushing means 40 are arranged at predetermined intervals so as to surround the introduction port 33.

  As the crushing means 40, other known means can be used. Further, the number of crushing means 40 may be one.

-Effect of Embodiment 1-
Therefore, according to this Embodiment 1, before the to-be-dried material A conveyed by airflow in the 1st airflow conveyance path 13 reaches | attains the heat exchanger 16 of the airflow type dryer 15, the to-be-dried material A is classify | categorized means 30. It can classify by. That is, among the objects to be dried A that are air-conveyed in the first air current conveyance path 13, the air-drying machine 15 does not air-convey the objects to be dried A ′ that are larger than the interval between the plates in the heat exchanger 16. Since only the object to be dried a smaller than the interval between the plates can be conveyed to the heat exchanger 16 of the airflow dryer 15, the clogging of the heat exchanger 16 by the relatively large object A ′ to be dried can be prevented.

  Moreover, since the classifying means 30 is provided in the first airflow conveyance path 13, it is not necessary to greatly increase the interval between the plates of the heat exchanger 16 in order to prevent the heat exchanger 16 from being clogged. Can be suppressed.

  In particular, since the classifying means 30 includes the enlarged diameter portion 32, the gas flow velocity in the enlarged diameter portion 32 is lower than the gas flow velocity in the first air flow path 13 on the upstream side of the enlarged diameter portion 32. Therefore, in the diameter-expanded portion 32, the air current conveying force of the object A to be dried is smaller than the upstream side thereof, so that the object A ′ to be dried that requires a relatively large conveying force is not air conveyed to the air dryer 15. Can be classified. As a result, only an object to be dried a that is smaller than the interval between the plates can be conveyed to the airflow dryer 15 by airflow.

  Furthermore, while forming the introduction port 33 in the lower part of the enlarged diameter part 32, and forming the discharge port 34 in the upper part of the enlarged diameter part 32, the to-be-dried material A 'larger than the space | interval of a plate rises from the introduction port 33. Then, when introduced into the enlarged diameter portion 32, the large object A ′ to be dried can be dropped to the lower inlet 33 side without being discharged from the upper outlet 34. Therefore, the to-be-dried object A can be classified easily with a simple configuration.

  Furthermore, the material to be dried A ′ larger than the interval between the classified plates can be temporarily retained in the retention portion 37. Further, since the staying portion 37 is provided with the crushing means 40, the material to be dried A 'larger than the interval between the staying plates can be crushed into the material to be dried a smaller than the interval between the plates. Since the crushed to-be-dried object a falls to the lower inlet 33 side along the inclined surface 36, the to-be-dried object a is conveyed upward by the airflow from the inlet 33 again. Therefore, the to-be-dried object A supplied to the classifying means 30 can be efficiently conveyed to the airflow dryer 15 by airflow.

  Here, assuming that the material to be dried is crushed in advance by providing a crushing means between the stirrer 12 and the heat exchanger 16, a relatively small material to be dried a that does not require crushing a. Since all of the material A to be dried is crushed by the crushing means, excessive energy consumption and wear of the crushing means become problems. Furthermore, since a crushing means having a large capacity is required, an increase in initial cost is inevitable.

  On the other hand, in this embodiment, not all the objects to be dried A are crushed, but only the relatively large objects to be dried A ′ classified by the classification means 30 are crushed, so that the crushing means 40 can be downsized. At the same time, the wear can be suppressed.

<< Embodiment 2 of the Invention >>
FIG. 4 shows a second embodiment of the present invention.

  FIG. 4 is an enlarged longitudinal sectional view showing the configuration of the enlarged diameter portion in the second embodiment. In the following embodiments, the same parts as those in FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The second embodiment is different from the first embodiment in the position of the introduction port 33 provided in the enlarged diameter portion 32.

  That is, as shown in FIG. 4, the enlarged diameter portion 32 constituting the classifying means 30 is formed in, for example, a bottomed container shape, and a staying portion 37 is formed in the bottom portion 42 thereof. Further, the crushing means 40 is provided in the staying portion 37. The crushing means 40 is constituted by a rotary crushing means having a rotating plate 38 and a crushing blade 39 as in the first embodiment, for example. The rotating plate 38 of the crushing means 40 can be made substantially the same size as the bottom portion 42, for example. A plurality of crushing means 40 may be provided on the bottom portion 42.

  An inlet 33 for introducing the material to be dried A is formed on the side of the enlarged diameter portion 32, while an outlet 34 for discharging the material to be dried a is formed on the upper portion of the enlarged diameter portion 32. . As a result, the material A to be dried conveyed from the side to the enlarged-diameter portion 32 is classified in the enlarged-diameter portion 32, and an object to be dried a that is smaller than the interval between the plates is discharged from the discharge port 34 to the air-flow dryer. The air flow is conveyed to 15.

  In addition, an inclined surface 35 is formed on the upper inner wall surface around the discharge port 34 in the enlarged diameter portion 32 so that the inner diameter gradually decreases upward as in the first embodiment.

  On the other hand, in the vicinity of the introduction port 33 in the duct 31 of the first airflow conveyance path 13, a gas injection unit 43 that injects a gas such as air downward is provided. It becomes possible to apply a downward force to the object to be dried A by the injection gas injected from the gas injection unit 43 and to guide the object to be dried A to the crushing means 40 more easily.

-Effect of Embodiment 2-
Therefore, also in the second embodiment, as in the first embodiment, the classifying means 30 for classifying the object to be dried A is provided in the first airflow conveyance path 13, so that the gas flow rate in the drying apparatus 1 is increased. While being suppressed, the heat exchanger 16 can be prevented from being clogged with a relatively large object A ′ to be dried.

  Further, since the airflow conveying force of the material A to be dried in the enlarged diameter portion 32 is smaller than the airflow conveying force on the upstream side, the relatively large dried material A ′ is airflowed from the enlarged diameter portion 32 to the airflow dryer 15. Only the article to be dried “a” smaller than the interval between the plates can be air-conveyed to the air-flow dryer 15 without being conveyed.

  Further, the inlet 33 is formed on the side of the enlarged diameter portion 32, while the outlet 34 is formed on the upper portion of the enlarged diameter portion 32, so that an object A ′ to be dried larger than the plate interval is introduced laterally. When introduced from the port 33 to the enlarged diameter portion 32, the large object to be dried A ′ can be dropped to the lower retention portion 37 without being discharged from the upper discharge port 34. Therefore, the to-be-dried object A can be classified easily with a simple configuration.

  Furthermore, the large to-be-dried material A ′ once classified and retained in the retaining portion 37 is crushed into the to-be-dried material a smaller than the interval between the plates, and the crushed to-be-dried material a is again sent by the air flow from the inlet 33. Since it can convey upward, the to-be-dried object A supplied to the classification means 30 can be efficiently conveyed by airflow to the airflow dryer 15.

  Furthermore, since not all the objects to be dried A are crushed but only a relatively large object to be dried A 'is crushed, the crushing means 40 can be downsized and its wear can be suppressed.

<< Other Embodiments >>
In the first and second embodiments, the example in which the crushing means 40 is provided in the staying portion 37 of the classification means 30 has been described. However, the crushing means 40 may not be provided in the staying portion 37.

  When the crushing means 40 is not provided, the relatively large dried material A ′ staying in the staying part 37 is blown up to a certain height again by the airflow from the inlet 33 and then falls to the staying part 37. While the rising and falling of the object to be dried A 'are repeated, the object to be dried A' is crushed and becomes smaller. Therefore, even in such a case, the object to be dried A that has become smaller than the interval between the plates in the heat exchanger 16 can be conveyed by airflow from the discharge port 34 to the airflow dryer 15. Therefore, since the crushing means 40 is not provided, the initial cost required for the crushing means 40 itself can be reduced, and the running cost required for driving the crushing means 40 can be reduced.

  As described above, the present invention is useful for a drying apparatus that introduces a material from a stirrer to a heat exchanger by airflow conveyance.

A, A '
B1 Dry matter for moisture adjustment
B2 Treated dry matter
C Hot gas
1 Drying equipment
12 Stirrer
13 First air flow path
15 Airflow dryer
16 Heat exchanger
30 classification means
31 Duct
32 Expanded part
33 Inlet
34 Discharge port
37 staying part
40 Crushing means

Claims (6)

An air current conveying path for air conveying an object to be dried;
A drying apparatus including a heat exchanger and an air flow dryer that dries the object to be dried, which is air-flowed by the air-flow conveying path, by the heat exchanger;
A drying device characterized in that the airflow conveying path is provided with a classifying means for classifying the material to be dried. The drying apparatus according to claim 1,
The said classification means has an enlarged diameter part with a larger internal diameter than the duct which comprises the said airflow conveyance path, The drying apparatus characterized by the above-mentioned. The drying apparatus according to claim 1 or 2,
The said classification means is provided with the crushing means which crushes the said to-be-dried material classified, The drying apparatus characterized by the above-mentioned. The drying apparatus according to claim 3,
The classifying means has a staying part in which the classified material to be dried stays,
The drying apparatus, wherein the staying part is provided with the crushing means. The drying apparatus according to claim 2,
An inlet for introducing the material to be dried is formed at the bottom of the enlarged diameter portion,
A drying apparatus, wherein a discharge port through which the material to be dried is discharged is formed in an upper part of the enlarged diameter portion. The drying apparatus according to claim 2,
An inlet for introducing the material to be dried is formed on the side of the enlarged diameter portion,
A drying apparatus, wherein a discharge port through which the material to be dried is discharged is formed in an upper part of the enlarged diameter portion.

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