Drying device

Abstract

To provide a new drying device capable of further improving drying efficiency. The device comprises a main tank (11) and multiple stages of rotating blades (30) arranged vertically along a rotation shaft (20) within the main tank (11). Between each rotating blade (30) and the blade (30) directly below, there is provided a co-rotating region where the material to be dried rotates in the direction of rotation of the rotating blade (30) and is in a thin film turbulent state as it reaches the blade (30) that has risen from the blade (30) directly below.

Description

[Technical Field]

[0001] The present invention relates to a drying device for drying materials of various types and shapes. [Background technology]

[0002] Conventionally, there are known dryers for drying various types and forms of materials to be dried, such as food waste, sludge, industrial waste, etc. In particular, the inventor of the present application has already proposed a dryer that can achieve ideal drying conditions by developing a unique dryer called a cyclone dryer (see, for example, Patent Documents 1 and 2).

[0003] In this type of drying device, the material to be dried is placed in a vertical cylindrical main tank and is then lifted up by the rotation of rotating lifting blades called cyclone fins attached to a vertical rotating shaft. With this configuration, when the rotating lifting blades rotate, the material to be dried is pressed into a thin film against the heat transfer surface on the inner wall of the main tank by centrifugal force, and this, combined with the action of the material to be dried being lifted up later pushing up the previously lifted material, enables the material to be dried efficiently.

[0004] The inventors of the present application have also proposed a drying apparatus in which rotary lifting blades are arranged in multiple stages, one above the other, and the spacing (clearance) between each stage can be set to an optimal dimension depending on the type of material to be dried (see, for example, Patent Document 3).In this type of drying apparatus, the spacing between each stage of the rotary lifting blades is set to a ratio of 0 to 15% of the diameter of the rotary lifting blade. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 2840639 [Patent Document 2] Patent No. 2958869 [Patent Document 3] Patent No. 5234869 Summary of the Invention [Problem to be solved by the invention]

[0006] In any of the conventional drying devices described above, there has been a demand for innovations to further improve drying efficiency. For example, as shown in Figure 7, in a conventional drying device equipped with multiple stages of rotating blades, if the lower surface of the upper rotating blade and the upper surface of the lower rotating blade are on the same plane, i.e., if the spacing between the multiple stages of rotating blades is zero, the material to be dried will flow in the direction of the thick arrow shown in Figure 7.

[0007] In the flow of materials to be dried as shown in Figure 7, the materials are placed on the rotating lifting blade and rise due to the inertial and centrifugal forces caused by the rotation. At this point, the materials move on the rotating lifting blade and continuously come into contact with the heat transfer surface of the inner wall of the main tank, moving at high speed while simultaneously being heated and evaporated. As a result, the materials placed on the rotating lifting blade form a thin film only on the rotating lifting blade, and this contact movement is repeated within the main tank. Here, the materials are placed on the rotating lifting blade and move at high speed as a thin film only on the rotating lifting blade, but high drying efficiency is achieved by the thin film heating and evaporation caused by the rotating lifting blade.

[0008] However, in the case of moving heating on the rotating blade, heating occurs only through momentary contact at the places where the rotating blade passes, and other heat transfer surfaces are not used. In other words, although the material to be dried comes into contact with most of the inner wall surface of the dryer, it is only momentary contact due to the rotation, and the areas other than this momentary contact (equivalent to about 70%) are not used at all times.

[0009] Therefore, by utilizing the heat transfer surface that is not normally in use, it is possible to further utilize the effective area of ​​the heat transfer surface, which is equivalent to about 30% of the conventionally used area, and thereby achieve even higher drying efficiency. This technical problem based on the inventor's new findings had not yet been strictly identified even at the time of filing the application for the drying device described in Patent Document 3, and there was still room for improvement in order to further improve drying efficiency.

[0010] The present invention has been made in light of new findings regarding the conventional technology as described above, and aims to provide a new drying device that can further improve the drying efficiency of conventional drying devices. [Means for solving the problem]

[0011] In order to achieve the above-mentioned object, one aspect of the present invention is to provide a method for manufacturing a semiconductor device comprising: A drying apparatus comprising: a vertical, cylindrical main tank into which materials to be dried are introduced; and a rotary lifting blade attached to a rotating shaft that extends along a substantially vertical centerline within the main tank; wherein, as the rotary lifting blade rotates, the materials to be dried in the main tank are pressed against a heated heat transfer surface on the inner wall of the main tank by centrifugal force and inertial force in the form of a thin film, and are then dried while rising, The rotary winding blades are provided in a plurality of stages arranged vertically along the rotary shaft, Each of the rotary take-up blades is characterized in that it is arranged so as to provide a co-rotating region between it and the rotary take-up blade immediately below, in which the material to be dried, which has risen from the rotary take-up blade immediately below, comes into contact with the heat transfer surface in the form of a thin film and rotates in the direction of rotation of the rotary take-up blade, creating a turbulent flow state as it reaches the heat transfer surface. [Effects of the Invention]

[0012] According to the drying device of the present invention, it is possible to further improve the drying efficiency based on new findings regarding conventional drying devices. [Brief explanation of the drawings]

[0013] [Figure 1]1 is a perspective view schematically illustrating the overall configuration of a drying device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view showing the lowest rotary winding blade in the drying device according to the embodiment. [Figure 3] FIG. 2 is a plan view showing the second and subsequent stages of rotary winding blades in the drying device according to the present embodiment. [Figure 4] 3 is an explanatory diagram showing the flow of materials to be dried in a main tank of the drying device according to the present embodiment. FIG. [Figure 5] 3 is an explanatory diagram showing how an object to be dried is dried in a main tank of the drying device according to the present embodiment. FIG. [Figure 6] 3 is an explanatory diagram showing the flow of materials to be dried in a main tank of the drying device according to the present embodiment. FIG. [Figure 7] FIG. 10 is an explanatory diagram showing the flow of materials to be dried in a main tank of a drying device according to the prior art. DETAILED DESCRIPTION OF THE INVENTION

[0014] The present inventors have further pursued intensive research into the drying apparatus they have been developing, and have discovered a new finding: between the multiple stages of rotating blades, the material to be dried rotates in the direction of rotation of the rotating blades, creating a thin film of turbulent flow, allowing for more effective use of a wider area of ​​the heat transfer surface of the main vessel. Based on this new finding, the present inventors have completed the present invention of a drying apparatus. Note that in the following description, detailed descriptions of already known matters and redundant descriptions of substantially identical configurations may be omitted as appropriate.

[0015] Hereinafter, a representative embodiment of the present invention will be described with reference to the drawings. The drying apparatus 10 according to this embodiment is an apparatus that dries materials to be dried while rolling them up after being placed in a vertical cylindrical main tank 11. Materials to be dried range widely, including food waste, sludge, livestock manure, and industrial waste, and come in a variety of forms, including granular, powdery, highly fluid liquid, and lumpy, with varying moisture contents. Note that the components, shapes, numerical values, and the like in the embodiments described below are merely examples of the present invention and do not limit the present invention.

[0016] <Outline of the drying device 10> As shown in Figure 1, the drying device 10 comprises a main tank 11, which forms the main part thereof, and rotary raising blades 30 attached to a rotary shaft 20 extending along a substantially vertical center line L within the main tank 11. In particular, the rotary raising blades 30 are arranged in multiple tiers, arranged vertically along the rotary shaft 20. The drying device 10 is configured so that the material to be dried in the main tank 11 is dried in the process of rising while being pressed into a thin film against the heat transfer surface 12a of the main tank 11 by centrifugal force and inertial force as the rotary raising blades 30 rotate in response to the rotation of the rotary shaft 20.

[0017] <Main tank 11> As shown in Fig. 1, the main tank 11 is made of a metal material and has a vertical cylindrical shape, with the interior being an enclosed space formed by a peripheral wall 12 forming the outer periphery, a bottom surface 14 closing the lower end, and an upper surface 15 closing the upper end. The main tank 11 is placed on the floor with a center line L aligned vertically by a plurality of legs 11a provided below the bottom surface 14.

[0018] The inner wall of the main tank 11 (peripheral wall 12) serves as a heat transfer surface 12a that transfers heat from the heating means to the inside. Here, the heating means includes, for example, a jacket 13 formed to surround the outer periphery of the main tank 11 (peripheral wall 12), and a boiler (not shown) connected to this jacket 13 so as to communicate with it and feeding, for example, steam into the jacket 13 as a heat medium.

[0019] The jacket 13 is formed to surround the outside of the peripheral wall portion 12 and is hollow inside. Although not shown, the jacket 13 is provided with an inlet for introducing steam, which is a heat medium, into the interior, and an outlet for discharging waste steam or water condensed from steam to the outside. The inlet is formed in a tubular shape, for example, at the upper end of the jacket 13, to which a pipe can be connected, and the outlet is formed in a tubular shape, for example, at the lower end of the jacket 13, to which a pipe can be connected.

[0020] As another example of the heating means, hot air may be sent into the jacket 13 instead of steam. As another heating means, the heating medium accommodated in the jacket 13 may be heated by an electric heater provided on the outer periphery of the jacket 13. Furthermore, the configuration of the heating means may be simplified so that heat from an electric heater provided on the outer periphery of the jacket 13 is directly transferred to the heat transfer surface 12a. As such, various heating means are possible.

[0021] There are various configurations for supplying the material to be dried into the main tank 11 and discharging it to the outside, and although not shown, it is preferable to provide an openable supply port in part of the top surface 15 of the main tank 11 and to feed the material to be dried into the inside through this supply port. On the other hand, it is preferable to provide an openable discharge port near the bottom surface 14 of the main tank 11 and to discharge the dried material to be dried (dried product) to the outside through this discharge port. With such a configuration, a batch-type process is performed in which the material to be dried is not supplied or discharged during the process until all steps are completed.

[0022] Alternatively, although not shown, a supply pipe may be connected to the peripheral wall near the bottom 14 of the main tank 11, and the material to be dried may be supplied into the main tank 11 through the supply pipe, while a discharge pipe may be connected to the peripheral wall near the top 15, and the dried material may be discharged to the outside through the discharge pipe. This configuration makes it possible not only to perform a batch process in which the supply of the material to be dried is divided and the dried material is obtained intermittently, but also to perform a continuous process in which the material to be dried is continuously supplied and the dried material is continuously discharged.

[0023] <Rotation axis 20> As shown in Fig. 1, a rotating shaft 20 extending along the vertical center line L is provided inside the main tank 11. The rotating shaft 20 is journaled while passing through the center of the bottom surface 14 and the top surface 15 of the main tank 11. The lower end of the rotating shaft 20 is rotatably supported by a lower bearing 21 provided on the bottom surface 14 of the main tank 11. Meanwhile, the upper end of the rotating shaft 20 is rotatably supported by an upper bearing 22 provided on the top surface 15 of the main tank 11.

[0024] An electric motor 23 is connected to the upper end of the rotating shaft 20, which protrudes above the upper bearing portion 22, via a gear box 24 so as to be able to transmit rotational force. The rotating shaft 20 is driven by the electric motor 23 to rotate in one direction (arrow R in FIG. 1) around the center line L. The electric motor 21 may be configured to be disposed below the bottom surface portion 14 rather than above the top surface portion 15. The rotating shaft 20 may also be configured to connect multiple rotating shaft portions that are aligned vertically on the same axis.

[0025] <Rotating winding blade 30> 1, multiple vertically arranged rotary winding blades 30 are provided on the rotary shaft 20. The rotary winding blades 30 according to this embodiment are provided in, for example, four vertical stages along the rotary shaft 20. That is, the rotary winding blades 30 are arranged with the lowest rotary winding blade 30A and the other rotary winding blades 30B to 30D above it, with a space S (described later) between them.

[0026] The rotary shaft 20 is driven to rotate by the power of the electric motor 21, and each of the rotary winding blades 30A to 30D is configured to rotate at the same rotational speed in synchronization with the rotary shaft 20. When referring to each of the rotary winding blades 30A to 30D collectively, they are also simply referred to as rotary winding blades 30. The specific number and arrangement of the rotary winding blades 30 are design matters that can be determined appropriately depending on the height and dimensions of the main tub 11.

[0027] Each of the rotary blades 30A to 30D basically consists of a plurality of base blades 31, 310 arranged circumferentially around the rotary shaft 20. Here, the lowest rotary blade 30A has, for example, three base blades 31, but the second and subsequent rotary blades 30B to 30D have a different configuration from the lowest rotary blade 30A, and are configured with, for example, nine base blades 310 and have the same shape.

[0028] <<Lowest rotating winding blade 30A>> As shown in Figure 1, the base blades 31 of the lowest rotating winding blade 30A are formed to be identical to each other and are arranged, for example, with a phase difference of approximately 120 degrees. Each base blade 31 is supported so as to extend continuously and narrowly from the tip of an arm 32 whose base end is attached to the rotary shaft 20. The arms 32 are aligned in a narrow width in the radial direction centered on the rotary shaft 20, and are inclined at a predetermined angle in the width direction relative to the bottom surface 14 of the main tank 11 to match the inclination of the base blades 31.

[0029] As a result, the arms 32 act to actively scrape up the materials to be dried that accumulate on the bottom surface 14. The materials to be dried scraped up by the arms 32 are configured to rest on the starting ends of the base blades 31. In other words, the lowest rotary winding blade 30A is equipped with a predetermined number (three) of base blades 31 that scrape up the materials to be dried on the bottom surface 14 of the main tank 11. The arms 32, together with the base blades 31, may be considered to be part of the rotary winding blade 30A.

[0030] More specifically, each base blade 31 extends in a circumferential direction around the rotary shaft 20 in a plan view, and has a flat surface 31a (see Figure 2) on which the material to be dried can be placed from its starting end connected to the tip of the arm 32 and wound up while moving it to its terminal end. This flat surface 31a is formed so as to extend obliquely upward from the starting end to the terminal end in the opposite direction to the rotation direction R (see Figure 1). Since the rotary winding blade 30A is particularly required to scrape up the material to be dried, each of the three base blades 31 has a length of 60 to 70 degrees in the circumferential direction.

[0031] The base blade 31 is configured to place the material to be dried on the flat surface 31a and roll it up, while pressing the material into a thin film against the heat transfer surface 12a of the main tank 11 by centrifugal force (see FIG. 5) and inertial force. The flat surface 31a extends with a constant width up to a length within a 360-degree circumferential range in a plan view, and the outer circumferential edge of the flat surface 31a is formed in an arc shape that follows the cylindrical shape of the heat transfer surface 12a. A gap U that allows the base blade 31 to rotate is provided between the outer circumferential edge of the flat surface 31a and the heat transfer surface 12a.

[0032] <<2nd and subsequent rotating winding blades 30B-30D>> The second-stage rotary take-up blade 30B has a space S1 (described later) between it and the lowest-stage rotary take-up blade 30A, and so is provided with more small base blades 310 called turbine fins than the base blades 31 of the rotary take-up blade 30A to prevent the material to be dried that has risen from the rotary take-up blade 30A from falling downward. In this embodiment, the second- to fourth-stage rotary take-up blades 30B to 30D are each configured to have the same shape.

[0033] That is, the base blades 310 of the third and subsequent rotary blades 30C, 30D are also shorter and smaller than the base blade 31 of the lowest rotary blade 30A. More specifically, the base blades 310 are arranged at equal intervals on the outer periphery of a wheel 301 fixed around the rotary shaft 20. The wheel 301 is fixed to the rotary shaft 20 via spokes 302.

[0034] Each base blade 310 is connected to the tip of a shaft-like arm 303 that extends radially from the outer periphery of the wheel 301. Nine arms 303 are provided, matching the number of base blades 310. Each base blade 310 is arranged so as to extend on a plane perpendicular to the axial direction of the rotating shaft 20, and its starting end is connected to the tip side of the arm 303. Each base blade 310 extends a short distance in the circumferential direction in a plan view, and has a flat surface 310a (see Figure 3) that can load the material to be dried from the starting end and move it to the end while winding it up.

[0035] The flat surface 310a of each base blade 310 is short but is formed so as to extend obliquely upward in the opposite direction to the rotation direction R (see FIG. 1). The base blade 310 is also configured to place the material to be dried on the flat surface 310a, roll it up, and press it into a thin film against the heat transfer surface 12a of the main tank 11 by centrifugal force and inertial force. The arm 303 that supports the base blade 310 does not need to have the function of scraping up the material to be dried. The arm 303, wheel 301, and spokes 302 may also be considered as a component that forms part of the rotating winding blade 30B, etc.

[0036] In this way, the second to fourth rotating blades 30B to 30D each have a greater number of base blades 310 than the base blades 31 (a predetermined number, for example, three) and the same or greater number of base blades 310 as the rotary blade 30 directly below, in order to scoop up the material to be dried that has risen from the rotary blade 30 directly below. In this embodiment, the rotary blades 30B to 30D each have the same shape, and therefore the number of base blades 310 is also the same.

[0037] However, the number of base blades 310 may be increased in the order of the second stage rotary winding blade 30B, the third stage rotary winding blade 30C, and the fourth stage rotary winding blade 30D. This makes it possible to reliably scoop up the material to be dried that has risen from the rotary winding blade 30 directly below at each stage, in succession, without allowing it to fall.

[0038] Furthermore, by shortening the length of the base blade 310, it is possible to reduce the vertical bulk compared to the base blade 31, and it is possible to minimize the overall height of each of the rotating winding blades 30B to 30D even if the number of base blades 310 is increased. Note that the specific number and shape of the base blades 310 of each of the second and higher stages of rotating winding blades 30B to 30D are design matters that can be determined as appropriate.

[0039] <Co-rotating area> As shown in Fig. 1, the arrangement of the vertically arranged multiple stages of rotating winding blades 30A to 30D is particularly important. As a result of extensive research by the present inventors into conventional drying devices, it was found that a new arrangement can change the flow of the materials to be dried in the main tank 11, thereby ensuring an area on the heat transfer surface 12a of the main tank 11 with which the materials are constantly in contact and heated.

[0040] This arrangement is due to the space S between the top and bottom of each of the rotary take-up blades 30A to 30D. That is, the rotary take-up blades 30A to 30D are arranged with a predetermined space S between them, so that a co-rotating region of the material to be dried is formed on the heat transfer surface 12a between the rotary take-up blade 30 directly below and the material to be dried, which has risen from the rotary take-up blade 30 directly below, reaches the rotary take-up blade 30 directly below. This co-rotating region is characterized by the fact that the material to be dried, which is in contact with the heat transfer surface 12a in a thin film form, simultaneously rotates in the rotation direction of the rotary take-up blade 30, i.e., a thin film turbulent flow state is created while rotating together. Here, the rotation speed of the material to be dried is slower than the rotation speed of the rotary take-up blade 30.

[0041] 4, a co-rotating region corresponding to space S1 is provided between the lowest (first) rotary scroll blade 30A and the second rotary scroll blade 30B. Here, space S1 is set to be the same height as the height from the bottom surface including the starting point of each base blade 31 of the rotary scroll blade 30A directly below it, including the top surface including the terminal end, using the upper rotary scroll blade 30B as a reference, so that the heat transfer surface 12a between the top and bottom of the rotary scroll blades 30A, 30B becomes the co-rotating region.

[0042] A co-rotating region corresponding to space S2 is provided between the second-stage rotary scroll blade 30B and the third-stage rotary scroll blade 30C. Here, space S2 is set to be the same height as the height from the bottom surface including the starting point of each base blade 31 of the rotary scroll blade 30B directly below it, including the top surface including the terminal end, using the upper-stage rotary scroll blade 30C as a reference, so that the heat transfer surface 12a between the top and bottom of the rotary scroll blades 30B, 30C becomes the co-rotating region.

[0043] Furthermore, a similar co-rotating region corresponding to space S2 is provided between the third-stage rotary scroll blade 30C and the fourth-stage rotary scroll blade 30D. Here, space S2 is also set to the same height as the height from the bottom surface including the starting point of each base blade 31 of the rotary scroll blade 30C directly below it, for example, using the upper-stage rotary scroll blade 30D as a reference, so that the heat transfer surfaces 12a between the top and bottom of the rotary scroll blades 30C, 30D become the co-rotating region.

[0044] In this embodiment, the rotary winding blades 30 are provided in a total of four stages, one above the other, but the specific number of stages of the rotary winding blades 30 can be two, three, five or more, depending on the height and dimensions of the main tank 11. If there are rotary winding blades 30 in the fifth stage or later, it is preferable to provide co-rotating regions corresponding to the space S2 thereafter, just as there are between the rotary winding blades 30 in the second to fourth stages.

[0045] <Function of the drying device 10> Next, the operation of the drying device 10 according to this embodiment will be described. The material to be dried is fed into the main tank 11 from a hopper or the like through a supply port on the top surface 15. Then, the electric motor 23 is driven to rotate the rotary shaft 20 in the R direction. At the same time, steam is introduced from a boiler into the jacket 13 to heat the heat transfer surface 12a. As the rotary shaft 20 rotates, the vertically arranged rotary vanes 30A to 30D rotate synchronously.

[0046] As shown in Figure 4, the material to be dried is scraped up on the bottom surface 14 of the main tank 11 by the arm 32 of the lowest rotary winding blade 30A and placed on the flat surface 31a from the starting end of each base blade 31. The material to be dried then moves upward from the starting end to the upper terminal end of each base blade 31, being scraped up and raised on the flat surface 31a in the opposite direction to the rotation direction R. The base blade 31 of the lowest rotary winding blade 30A is longer than the base blades 310 of the second and subsequent stages, and therefore exerts a greater scraping force.

[0047] As shown in Figure 5, the material to be dried on the flat surface 31a of the base blade 31 is pressed into a thin film against the heat transfer surface 12a in the main tank 11 by centrifugal force and inertial force. Here, the material to be dried has an interface surface that contacts the heat transfer surface 12a and an evaporation surface on the opposite side that contacts the air in the space inside the main tank 11. Then, a certain amount of moisture evaporates from the material to be dried that comes into contact with the heat transfer surface 12a due to the heat from the heat transfer surface 12a. The material to be dried, whose moisture content has decreased due to the evaporation of moisture when it comes into contact with the heat transfer surface 12a, moves to the evaporation surface to replace the material to be dried that has a higher moisture content.

[0048] The material to be dried that has moved to the evaporation surface is exposed to air, which causes further evaporation of moisture. Also, as the material to be dried moves from the heat transfer surface 12a side to the evaporation surface, the material to be dried that is being rolled up by each base blade 31 continuously pushes against the material that was rolled up earlier, causing the material to rise along the heat transfer surface 12a. In other words, the material to be dried moves from the heat transfer surface 12a to the evaporation surface, rolling up along the heat transfer surface 12a and drying as it rises.

[0049] Above the lowest rotary take-up blade 30A, multiple stages of rotary take-up blades 30B to 30D are lined up, with a space S between them. Therefore, as described above, the material to be dried picked up by the lowest rotary take-up blade 30A comes into contact with the heat transfer surface 12a, is heated, and rises while evaporating, but there is a space S1 between the first and second stages. This space S1 prevents the material from immediately landing on the second rotary take-up blade 30B, and in the co-rotating region created by the space S1, the material rotates in the same direction as the rotary take-up blade 30 while in contact with the heat transfer surface 12a in a thin film form (see the arrow in Figure 4).

[0050] When the materials to be dried begin to rotate together, the interface between the heat transfer surface 12a and the materials becomes a thin film and turbulent in the region where they rotate together, causing a phenomenon known as turbulent thin film contact at the interface, resulting in high-speed heating and evaporation. However, because the lowest rotating blade 30A is primarily intended for scraping, each blade has only three base blades 31, which are spaced far apart, causing some of the materials to fall downward as they rotate together. To prevent this, the second rotating blade 30B has small base blades 310, the number of which is set equal to or greater than the base blades 31 of the lowest rotating blade 30A. The specific number of base blades 31 is a design factor that varies, for example, depending on the diameter of the main tank 11.

[0051] Next, the material to be dried, which is rotating together in the co-rotating region of the space S1 between the first and second stages, must be raised to reach the second-stage rotating take-up blade 30B. In this co-rotating region of the space S1, the material to be dried is completely distributed over the entire area of ​​the heat transfer surface 12a, and a highly efficient heating phenomenon occurs due to the interfacial thin film turbulent contact phenomenon. The rotational speed of this co-rotating material is slower than that of the rotating take-up blade 30, but it is reliably scraped off before falling by the numerous small base blades 310 of the second-stage rotating take-up blade 30B. In this way, the material to be dried is transferred from the rotating take-up blade 30A onto the rotating take-up blade 30B, and then comes into contact with the heat transfer surface 12a, where it rises while being heated and evaporated.

[0052] Next, in the co-rotating region of the space S2 between the second and third stages, the material to be dried also rotates together with the material, and in this co-rotating region, the material to be dried is completely distributed over the entire area of ​​the heat transfer surface 12a, resulting in the interfacial thin film turbulent contact phenomenon. The material to be dried is then scraped off by the base blade 310 of the third stage rotating blade 30C, which has a similar configuration to that of the second stage, before it falls, just as it did from the first stage. In this way, the material to be dried is transferred from the rotating blade 30B onto the rotating blade 30C and rises. The material then continues to move to the upper rotating blade 30D, where it is heated and evaporated in the same manner.

[0053] By arranging the rotary take-up blades 30A-30D in multiple stages, the entire area of ​​the heat transfer surface 12a in the space from the lowest rotary take-up blade 30A to the highest rotary take-up blade 30D is utilized. In particular, in the co-rotating region, a thin film turbulent contact phenomenon occurs at the interface between the heat transfer surface 12a and the material to be dried, resulting in a dedicated heat transfer area ratio of 40% or more inside the main tank 11. Furthermore, if the 30% area where the material to be dried is placed and moves and comes into contact on each base blade 31, 310 of the rotary take-up blades 30A-30D is added, more than 70% of the total area of ​​the heat transfer surface 31a becomes a complete contact heating and evaporation area, achieving a drying efficiency more than double that of conventional dryers.

[0054] <Configuration and effects of the present invention> Although various embodiments of the present invention have been described above, the present invention is not limited to the above-described various embodiments. The present invention derived from the above-described various embodiments will be described below.

[0055] First, the present invention provides a drying device 10 comprising a vertical cylindrical main tank 11 into which materials to be dried are introduced, and a rotary raising blade 30 attached to a rotary shaft 20 along a substantially vertical center line within the main tank 11, wherein the rotation of the rotary raising blade 30 causes the materials to be dried in the main tank 11 to be pressed against a heated heat transfer surface 12a on the inner wall of the main tank 11 in the form of a thin film by centrifugal force and inertial force, and the materials to be dried rise and dry. The rotary winding blades 30 are provided in multiple stages aligned vertically along the rotary shaft 20, The rotary take-up blades 30 are characterized in that they are arranged so as to provide a co-rotating region between the rotary take-up blade 30 immediately below and the material to be dried that has risen from the rotary take-up blade 30 immediately below reaches the rotary take-up blade 30, where the material to be dried comes into contact with the heat transfer surface 12a in the form of a thin film and rotates co-rotatingly in the direction of rotation of the rotary take-up blade 30, creating a thin film turbulent flow state.

[0056] In the drying apparatus 10, the material to be dried rotates in the co-rotating region between the rotating take-up blades 30 of each stage in the main tank 11 at a slower rotation speed than the rotating take-up blades 30. At this time, the material to be dried enters a thin film turbulent state at the interface where it contacts the heat transfer surface 12a, particularly in the co-rotating region, causing the so-called interface thin film turbulent contact phenomenon.

[0057] This allows the entire area of ​​the heat transfer surface 12a to be effectively utilized, further improving drying efficiency.On the other hand, in the drying device described in the above-mentioned Patent Document 3, the spacing (clearance) between the rotary lifting blades of each stage was designed simply to increase or decrease the contact area of ​​the material to be dried with the heat transfer surface, and was not intended to ensure that the material to be dried rotates together with the heat transfer surface.

[0058] That is, in the drying apparatus described in Patent Document 3, when the gap between the upper and lower rotating take-up blades is 0 to 15% of the diameter or less, thin-film turbulent contact due to co-rotation does not occur, but by narrowing or widening the gap between the base blades, scraping of the material to be dried is possible even when the gap between the upper and lower blades is widened. Therefore, by widening the gap between the upper and lower rotating take-up blades, the phenomenon of co-rotation of the material to be dried can occur, and thin-film turbulent contact can occur.

[0059] However, if the circumferential spacing of the rotary winding blades is wide, widening the gap between the upper and lower rotary winding blades will cause the material to fall down before it can rotate together. Therefore, in the present invention, as will be described below, by providing many smaller base blades in the second and subsequent rotary winding blades, it is possible to scrape and lift the material to the upper rotary winding blade without it falling.

[0060] In the present invention, the rotary winding blades 30 each include a plurality of base blades 31, 310 arranged in a circumferential direction around the rotary shaft 20, The lowest rotating lifting blade 30A has a predetermined number of base blades 31 capable of lifting up the material to be dried on the bottom surface 14 of the main tank 11, The rotary winding blades 30B to 30D above the lowest rotary winding blade 30A are characterized by having base blades 310 that are greater than the predetermined number and equal to or greater than the number of the rotary winding blade 30 directly below, so that they can scoop up the material to be dried that has risen along the co-rotating region from the rotary winding blade 30 directly below.

[0061] With this configuration, the materials to be dried rising from the lower stage to the upper stage rotary lifting blade 30 can be reliably scooped up without dropping unnecessarily. Therefore, the entire heat transfer surface 12a in the vertical direction inside the main tank 11 can be effectively utilized without any leakage, and extremely high drying efficiency can be reliably achieved by taking advantage of the vertical type.

[0062] In the present invention, each of the base blades 31, 310 of the rotary winding blade 30 extends in the circumferential direction in a plan view and has a flat surface 31a, 310a on which the material to be dried can be placed from the starting end and wound up while moving it to the terminal end, and the flat surface 31a, 310a is formed so as to extend obliquely upward from the starting end to the terminal end in the direction opposite to the rotation direction, The distance between the top and bottom of each rotary winding vane 30 is set to be the same as the height from the bottom surface, including the starting point, of each base vane 31, 310 of the rotary winding vane 30 directly below to the top surface, including the terminal end, of each base vane 31, 310, so that the heat transfer surface 12a between the top and bottom of each rotary winding vane 30 becomes the co-rotating region. This configuration of the base blades 31, 310 in the rotary winding blades 30 for each stage makes it possible to effectively perform the winding-up action on the material to be dried as it rises from the lower stage to the upper stage of the rotary winding blades 30 and the pressing action against the heat transfer surface 12a.

[0063] Furthermore, in the present invention, each base blade 31 of the lowest rotary lifting blade 30A extends radially from the rotary shaft 20 and is supported on the tip of an arm 32 capable of scraping off the material to be dried on the bottom surface 14 of the main tank 11, The base blades 310 of the rotary winding blades 30B to 30D above the lowest rotary winding blade 30A are arranged at equal intervals along the outer periphery of a wheel 301 fixed around the rotary shaft 20, and are supported on the tips of arms 303 extending radially from the rotary shaft 20.

[0064] This specific configuration of each base blade 31, 310 allows each of the rotary spiral blades 30A to 30D to be easily realized, further improving drying efficiency. In particular, with regard to each base blade 310 of the rotary spiral blades 30B to 30D, a portion of the base blade 310 does not extend near the rotary shaft 20, and it is possible to efficiently and intensively arrange the base blade 310 near the heat transfer surface 12a.

[0065] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configurations are not limited to these embodiments, and the present invention also includes modifications and additions that do not deviate from the gist of the present invention.

[0066] For example, although the rotary winding blades 30A to 30D are generally arranged in four vertical rows, the specific number and arrangement of the rotary winding blades 30 are design matters that are determined appropriately according to the height and dimensions of the main tank 11. Furthermore, the number and shape of the base blades 31, 310 in the rotary winding blades 30A to 30D are not limited to those shown in the drawings. [Industrial Applicability]

[0067] The drying device of the present invention can be adapted to various types of materials to be dried, and can be widely used as a drying device that can efficiently dry not only highly fluid liquid materials, but also materials that include solids and semi-solids, and highly viscous materials. [Explanation of symbols]

[0068] 10...Drying device 11…Main tank 12...Peripheral wall part 12a...heat transfer surface 13...Jacket 14...Bottom part 15...Top part 20...Rotation axis 30A~30D...Rotating winding blades 31,310...Base blade 32,303...Arm

Claims

1. A drying apparatus comprising: a vertical, cylindrical main tank into which materials to be dried are introduced; and a rotary lifting blade attached to a rotating shaft that extends along a substantially vertical centerline within the main tank; wherein, as the rotary lifting blade rotates, the materials to be dried in the main tank are pressed against a heated heat transfer surface on the inner wall of the main tank by centrifugal force and inertial force in the form of a thin film, and are then dried while rising, The rotary winding blades are provided in a plurality of stages arranged vertically along the rotary shaft, each rotating take-up blade is disposed between itself and the rotating take-up blade immediately below, such that a co-rotating region is provided between itself and the rotating take-up blade immediately below, in which the material to be dried, having risen from the rotating take-up blade immediately below, reaches the heat transfer surface in the form of a thin film, and rotates co-rotatingly with the rotating take-up blade in the direction of rotation thereof, thereby creating a thin film turbulent flow state; Each of the rotary winding blades includes a plurality of base blades arranged in a circumferential direction around the rotary shaft, and each of the base blades extends in the circumferential direction in a plan view and has a flat surface on which the material to be dried can be placed from its starting end and wound up while moving it to its terminal end, and the flat surface is formed so as to extend obliquely upward from its starting end to its terminal end in a direction opposite to the direction of rotation, each base blade of the lowest rotary lifting blade among the rotary lifting blades extends radially from the rotary shaft as a center and is supported on the tip of an arm capable of scraping off the material to be dried on the bottom surface of the main tank; the rotary blades above the lowest rotary blade comprise a wheel fixed by spokes around the rotary shaft, and the base blades arranged at equal intervals on the outer periphery of the wheel; the wheel is cylindrical and concentric with the heat transfer surface, and is set to a height from the start point to the end point of each of the base blades arranged on the outer periphery of the wheel, and the inside of the wheel forms a space that is directly connected vertically except for the spokes, The number of base blades arranged on the outer periphery of the wheel is greater than the number of base blades of the lowest rotating winding blade, and each base blade has its starting end supported on the tip of an axial arm extending radially from the outer periphery of the wheel.

2. A drying device as described in Claim 1, characterized in that the rotating winding blades above the lowest rotating winding blade have a greater number of base blades as they go up.

3. A drying device as described in Claim 2, characterized in that the distance between the top and bottom of each rotating winding blade is set to be the same as the height from the bottom surface including the starting point of each base blade of the rotating winding blade directly below to the top surface including the ending point, so that the heat transfer surface between the top and bottom of each rotating winding blade becomes the co-rotating area.

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