JP2012093036A - Drum type dryer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drum type dryer capable of effectively drying solution.SOLUTION: The drum type dryer 100 has a laterally arranged hollow drum 8, a motor 12 for rotating the drum, a solution supplying tube 19 for supplying the solution to inside of the drum 8, a high temperature gas supplying tube 21, a scraper 20, and a conveyor 22. The solution attaching to the inner surface of the rotating drum 8 is heated and dried by the high temperature gas blown by the high temperature gas supplying tube 21. The scraper 20 slidably comes into contact with the inner surface of the drum 8 and scrapes down the remaining subject after drying the solution attached to the inner surface of the rotating drum 8. The conveyor 22 extends along the scraper 20 below the scraper 20 and is extended to the outside of the drum, and receives and conveys the remaining subject scraped down by the scraper 20 out to the outside of the drum.

Description

  The present invention relates to a drum dryer for drying a solution. The term “solution” in this specification includes not only a solution containing a non-volatile component but also a suspension (so-called slurry) in which a liquid and an insoluble solid substance are mixed.

  One type of apparatus for drying a solution and obtaining a residue of non-volatile components in the solution is an apparatus called a drum dryer. Conventional drum dryers apply a solution to the outer peripheral surface of the drum, heat and dry the solution while rotating the drum, and scrape the residue adhering to the outer surface of the drum with a scraper that is in sliding contact with the outer peripheral surface of the rotating drum. Drop it. Patent Document 1 and Patent Document 2 disclose examples of such a drum dryer.

  As an example of the solution targeted by the conventional drum dryer, there is a paint after use after being used for manufacturing a product in a factory or the like. If the paint after use is dried, the capacity is reduced, and the cost of subsequent processing such as disposal can be reduced.

JP 2001-248966 A JP 2005-326053 A

  As far as the inventors have investigated, as exemplified in Patent Document 1 or Patent Document 2, the type of applying the solution to the outer peripheral surface of the drum has been scattered, but the type of applying to the inner peripheral surface has not been found. The inventors changed the way of thinking and found that if the solution was applied to the inner peripheral surface of the drum, several advantages were obtained over the conventional drum-type dryer utilizing the outer peripheral surface. The present specification discloses a drum dryer having advantages over conventional drum dryers whose outer peripheral surfaces have been utilized for solution drying.

  An aspect of the drum type dryer disclosed in the present specification is a hollow drum arranged in a horizontal direction, a driving unit that rotates the drum, a solution supply unit that supplies a solution, and a heating unit that heats and dries the solution. And a scraper and an unloading means for unloading the residue out of the drum.

  “Arranging the drum horizontally” refers to arranging the drum so that the drum axis (center line) faces in the horizontal direction (typically the horizontal direction). It should be noted that the drum axis is not limited to being strictly horizontal. The drum only needs to face in the lateral direction so that the solution supplied to the drum is not significantly biased by the action of gravity. That is, if the viscosity of the solution is high, the drum may be inclined to some extent (for example, about 10 degrees with respect to the horizontal).

  The solution supply means supplies the solution into the drum from the outside (axially outside) of the drum. The heating means heats and dries the solution adhering to the inner surface of the rotating drum. The scraper is disposed in parallel with the drum axis inside the drum. The scraper is fixed by a support member extending from the outside of the drum, and is in sliding contact with the rotating drum inner surface. The scraper scrapes off the residue after drying of the solution adhering to the inner surface of the rotating drum.

  The carry-out means is disposed along the scraper below (typically directly below) the scraper. The carry-out means further extends outward in the drum axial direction, and receives the residue scraped off by the scraper and carries it out of the drum. The carry-out means may simply be a ridge (U-shaped member) inclined downward from the inside of the drum toward the outside of the drum. Alternatively, the carry-out means may be a belt conveyor or a vibration type conveyor.

  In the drum dryer described above, since the scraper and other equipment are arranged inside the drum, the entire dryer becomes compact.

  One aspect of the solution supply means may simply supply (for example, drop) the solution to the inner bottom of the drum. Alternatively, in another aspect of the solution supply means, a solution plate is provided on the upstream side of the rotation direction of the drum in the rotation plate, including a plate extending in parallel with the drum axis and arranged with a gap from the drum inner surface. Is preferably supplied so that the solution uniformly adheres to the inner surface of the drum through the gap between the gutter plate and the inner surface of the drum as the drum rotates. The latter allows the solution to adhere to the drum with a uniform film thickness. A typical layout of the latter may be a plate that extends parallel to the drum axis inside the drum and is inclined downward toward the gap side.

  A simple aspect of the heating means may be a gas supply pipe that blows out hot gas from one end of the drum toward the inside of the drum. Another more preferable aspect of the heating means has a plurality of blowing holes for blowing the hot gas toward the inner surface of the drum, and the plurality of blowing holes are formed on the drum inner surface and a part of the drum circumferential direction. It is good to arrange | position two-dimensionally facing the partial inner surface over the substantially full length of a direction. Alternatively, still another aspect suitable as a heating means includes a gas chamber disposed inside the drum and a gas supply means for supplying a high-temperature gas into the gas chamber. It is good to have the opposing surface which opposes the partial inner surface over a part of direction and the drum longitudinal direction substantially full length, and it is good for the opposing surface to be provided with several blowing holes in two dimensions.

  The drying speed of the solution depends on the overall heat transfer coefficient of the gas (gas) that touches the solution. In order to increase the overall heat transfer coefficient, a high temperature gas may be flowed at a high speed on the surface of the solution. The plurality of two-dimensionally arranged blow holes are suitable for flowing a high-temperature gas on the surface of the solution at a high speed. Therefore, the solution can be efficiently dried by providing a plurality of blowing holes.

  Another advantage of attaching the solution to the inner surface of the drum is that the hot gas is sprayed from the inside of the curved surface, so that the hot gas is likely to spread along the curved surface as compared with the case of spraying from the outside of the curved surface ( Conversely speaking, it is difficult to dissipate from the vicinity of the curved surface), and the drying efficiency is improved. In addition, when employ | adopting a gas chamber, a mesh board may be sufficient as an example of the above-mentioned opposing surface. Further, the opposing surface is located upstream of the scraper in the drum rotation direction and downstream of the dry matter attachment start position.

  The drum dryer disclosed in the present specification is suitable for drying a solution containing VOC (Volatile Organic Compound). Since the volatilized organic compound gas (VOC gas) has a relatively high energy, it can be reused as a fuel gas. In order to efficiently collect the VOC gas that volatilizes from the solution by drying, it is preferable that the drum dryer disclosed in the present specification further has the following configuration. That is, the heating means includes a gas circulation path that collects and heats the high-temperature gas flowing out of the drum and blows it back into the drum, and also includes a mixing valve that mixes outside air with the circulating gas. Yes. The drum dryer having such a configuration can increase the concentration of the VOC gas by the gas circulation path, and at the same time, the mixing valve of the outside air can be within the range in which the quality of the high temperature gas is suitable for solution drying. The gas concentration can be adjusted.

  When a gas circulation path is provided and the VOC gas concentration can be increased, the drum dryer preferably further includes the following configuration. That is, the drum dryer includes a gas sensor that measures the concentration of the VOC gas in the drum, and a controller that decreases the drum rotation speed when the gas concentration measured by the gas sensor exceeds the first threshold concentration. Furthermore, it is preferable that the controller reduces the flow rate of the hot gas blown into the drum when the gas concentration exceeds a second threshold concentration higher than the first threshold concentration. Alternatively, the controller may adjust the opening degree of the mixing valve so as to increase the introduction amount of the outside air mixed with the circulating gas when the gas concentration exceeds the third threshold concentration higher than the first threshold concentration. preferable. The generation of VOC gas is suppressed by reducing the drum rotation speed. If the increase in gas concentration cannot be suppressed only by reducing the drum rotation speed, the flow rate of high-temperature gas blown into the drum is reduced, or the amount of outside air introduced is increased to prevent the gas concentration from excessively increasing.

  The present specification provides a drum dryer having advantages over conventional drum dryers in which the outer peripheral surface of the drum is utilized.

The cross-sectional view of the drum type dryer of an Example is shown. The longitudinal cross-sectional view along the II-II line | wire of FIG. 1 is shown. The longitudinal cross-sectional view along the III-III line of FIG. 1 is shown. 1 shows a schematic perspective view of an end of a drum. The cross-sectional view of the drum type dryer of 2nd Example is shown. The longitudinal cross-sectional view of the drum type dryer of 3rd Example is shown. The cross-sectional view of the drum type dryer of 4th Example is shown.

  In FIG. 1, the cross-sectional view of the drum type dryer 100 of 1st Example is shown. Here, the “cross section” means a section perpendicular to the drum axis (center line). 2 shows a longitudinal section along the line II-II in FIG. 1, and FIG. 3 shows a longitudinal section along the line III-III in FIG. First, an outline of the drum dryer 100 will be described. The drum dryer 100 is a solution such as a paint used in a coating factory or a printing factory, and is used for drying a solution containing VOC (Volatile Organic Compound). The solution is dried to reduce its volume, and vaporized VOC gas is collected from the solution and used as energy.

  The drum dryer 100 applies a solution to the inner peripheral surface of the drum 8 disposed in the housing 7, dries the solution with a high-temperature gas while the drum 8 rotates, and remains after the solution is dried by the scraper 20. Scrap off things. Note that “drying” includes not only the case where moisture is completely removed, but also the case where drying is performed to a degree of mud. 1 indicates the solution supplied into the drum 8, reference A2 indicates the solution applied to the inner surface of the drum 8, and reference A3 indicates the residue after drying scraped off by the scraper 20. Shows things. The VOC contained in the solution volatilizes from the solution as the solution is dried. The volatilized VOC-containing gas (VOC gas) is recovered through the VOC gas recovery pipe 14 and sent to a gas utilization device such as a gas generator or a heating device. In other words, the drum dryer 100 can be said to be a VOC gas recovery dryer that dries a solution containing VOC (volatile organic compound) and recovers vaporized VOC gas.

  Hereinafter, the structure of the drum dryer 100 will be described in detail. For simplicity, the drum dryer 100 is simply referred to as the dryer 100. The drum 8 is hollow and its both ends are open. The drum 8 is disposed sideways (horizontal) inside the sealed casing 7. The drum 8 is supported by rollers 9 and 10 and rotates about the axis thereof. A motor 12 is connected to one of the rollers 10 via a drive belt, and this motor 12 rotates the drum 8. In FIG. 1, the drum 8 rotates clockwise.

  The solution containing VOC is supplied from the outside of the housing to the inside of the drum 8 through the solution supply pipe 19. As shown in FIG. 3, both ends of the drum 8 are open, and the solution supply pipe 19 communicates from one open end of the drum 8 to the inside of the drum 8. A solution supply amount adjustment valve 18 is provided in the middle of the solution supply pipe 19. Inside the drum 8, a gutter plate 24 is disposed immediately below the opening of the solution supply pipe 19. As shown in FIG. 3, the flange plate 24 is supported by a support column extending from the housing 7 through the opening end of the drum 8. As shown in FIG. 3, the flange plate 24 extends parallel to the drum axis over substantially the entire length in the drum longitudinal direction. As shown in FIG. 1, the gutter plate 24 is disposed so as to be inclined downward toward one side close to the inner surface of the drum. One of the sides separates the gap G from the inner surface of the drum 8. The size of the gap G is about 1.0 mm to 10.0 mm. The solution A1 is supplied to the upper side (upstream side in the drum rotation direction) of the guard plate 24. As the drum 8 rotates, the supplied solution A1 flows out from the gap G along the inner surface of the drum 8 with a uniform thickness. That is, the solution uniformly adheres to the inner surface of the drum 8 with a thickness corresponding to the gap G (see symbol A2 in FIG. 1). Note that fine irregularities are provided on the inner surface of the drum 8 so that the solution can easily adhere to the drum 8.

  A gas chamber 23 is provided inside the drum 8. As shown in FIG. 2, the gas chamber 23 is supported by a support column extending from the housing 7 through the open end of the drum 8. The gas chamber 23 blows out high-temperature gas stored therein from a number of blowout holes 23a. The gas chamber 23 has substantially the same length as the entire length of the drum 8. A part of the side surface of the gas chamber 23 is opposed to a partial inner surface of the inner surface of the drum 8 that extends over a part in the drum circumferential direction and substantially the entire length in the drum longitudinal direction. The opposing surfaces are referred to as opposing surfaces. A plurality of blowing holes 23a are two-dimensionally arranged on the facing surface. As is clear from FIGS. 1 to 3, the plurality of blowing holes 23 a are arranged along the drum longitudinal direction and also arranged in the drum circumferential direction. The plurality of blowout holes 23 a blow out the high temperature gas toward the solution A <b> 2 attached to the inner surface of the drum 8. Naturally, the plurality of blowing holes 23a (opposing surfaces) are disposed downstream of the flange plate 24 in the drum rotation direction and upstream of the scraper 20 (described later) in the drum rotation direction. A high temperature gas is supplied to the gas chamber 23 through the gas supply pipe 21. As shown in FIG. 2, the gas supply pipe 21 communicates from one open end of the drum 8 to the inside of the drum 8. The structure for supplying the high temperature gas will be described in detail later.

  VOCs are vaporized from the solution adhering to the inner surface of the drum by the high temperature gas blown from the plurality of blow holes 23a, and the solution is dried. As is clear from FIGS. 1 to 3, the plurality of blowing holes 23 a blow out the high temperature gas from the inside of the drum 8 toward the curved inner surface of the drum. And flows at high speed. In general, the vaporization rate of the liquid depends on the overall heat transfer coefficient of the gas in contact with the liquid, but the overall heat transfer coefficient increases as the gas velocity increases. That is, the dryer 100 can dry the solution efficiently by applying the solution to the inner surface of the drum.

  The adhered solution dries while the drum 8 rotates, and solidifies (at least becomes muddy) before reaching the vicinity of the scraper 20. The scraper 20 extends along the drum axis substantially over the entire length in the drum longitudinal direction. Although not shown, the scraper 20 is also supported by a support column extending from the housing 7 through the opening end of the drum 8, similarly to the plate 24 and the gas chamber 23. One side of the scraper 20 is in contact with the inner surface of the drum 8 and slides as the drum 8 rotates. The solution residue that has reached the scraper 20 is scraped off by the scraper 20 as the drum 8 rotates. A vibration type conveyor 22 is disposed immediately below the scraper 20. The conveyor 22 is supported by the housing 7 through one open end of the drum 8. The conveyor 22 extends along the scraper 20 and extends outward in the axial direction of the drum 8. The residue A3 scraped off falls on the conveyor 22. The scraped residue A3 is carried out of the drum 7 by the conveyor 22 and stored in the storage tank 50.

  Next, a hot gas supply path for drying the solution will be described. The hot gas blown out from the gas chamber 23 flows along the inner surface of the drum 8, and then flows out of the drum 8 from the end opening of the drum 8. The high-temperature gas that has flowed out of the drum 8 contains VOC gas that has been vaporized from the solution. A gas reflux pipe 6 is attached to the wall surface of the casing 7, and the high-temperature gas that has flowed out of the drum is sent to the heater 2 through the gas reflux pipe 6. The heater 2 heats the collected high-temperature gas and raises the temperature to a temperature suitable for drying the solution. From the heater 2, the above-described gas supply pipe 21 extends to the gas chamber 23. That is, the gas reflux pipe 6 and the gas supply pipe 21 constitute a high-temperature gas circulation path 30 together with the heater 2, and the circulation path 30 collects and heats the high-temperature gas discharged to the outside of the drum, and again in the drum. To blow. In the middle of the gas reflux pipe 6, a mixing valve 4 for mixing the outside air with the high temperature gas and a fan 3 for adjusting the flow rate of the high temperature gas blown into the drum are provided. Reference numeral 5 denotes an outside air pipe for introducing outside air. As the solution adhering to the inner surface of the drum 8 dries, VOC gas evaporates from the solution and mixes with the hot gas. The gas circulation path 30 can increase the concentration of VOC contained in the high-temperature gas. The casing 7 seals the drum 8, and the gas circulation path 30 reheats the high-temperature gas flowing out from the inside of the drum 8 to the casing 7 and recirculates it into the drum 8.

  The casing 7 is also connected with a gas recovery pipe 14 that recovers the high-temperature gas containing VOC from the casing 7 and leads it to other gas-using devices. A fan 16 for adjusting the flow rate of the recovered gas is installed in the middle of the gas recovery pipe.

  Other structures provided in the dryer 100 will be described. The casing 7 is provided with a gas sensor 17 that measures the VOC concentration in the drum (inside the casing). The casing 7 is also provided with an outside air pipe that guides the outside air directly into the casing 7, and a closing damper 13 that opens and closes the outside air pipe is installed in the middle. Further, as shown in FIG. 4, a dam plate 8 a that rises from the inner surface of the drum toward the center is provided at the end of the drum 8. The weir plates 8a are provided at both ends of the drum 8, and prevent the applied solution from leaking out of the drum and also prevent the hot gas flowing along the drum inner surface from flowing out of the drum as it is. The weir plate 8a does not need to extend to the center of the drum, and may be high enough to prevent leakage of the solution and leakage of high temperature gas in the vicinity of the drum inner surface. For example, the height of the weir plate 8a may be about 10 cm. The dryer 100 also includes a controller (not shown) that controls the supply amount of the solution and the flow rate of the hot gas.

  The function of the controller will be described. The controller controls the opening of the solution supply amount adjustment valve 18 to adjust the solution supply amount into the drum. The controller controls the motor 12 and controls the number of rotations of the drum 8. The controller controls the heating temperature of the heater 2, the mixing valve 4, and the fan 3 to control the temperature of the hot gas blown into the drum 8, the VOC concentration contained in the hot gas, and the flow rate. Note that the amount of outside air mixed with the high temperature gas is adjusted by the mixing valve 4, thereby adjusting the VOC concentration contained in the high temperature gas.

  By providing the gas circulation path 30, a high-temperature gas containing VOC at a high concentration circulates inside the dryer 100. The controller performs the following control to increase the safety of the dryer. The controller decreases the drum rotation speed when the VOC concentration measured by the gas sensor 17 exceeds the first threshold concentration. Decreasing the number of revolutions of the drum 8 results in a decrease in the amount of solution supplied to the drum 8 and a decrease in the amount of VOC that is vaporized. Further, when the VOC concentration exceeds the second threshold concentration higher than the first threshold concentration, the controller controls the fan 3 to reduce the flow rate of the hot gas blown into the drum 8. Alternatively, when the VOC concentration exceeds the third threshold concentration higher than the first threshold concentration, the controller controls the mixing valve 4 to increase the amount of outside air introduced into the circulating high-temperature gas. Here, the first threshold density <the second threshold density, and the first threshold density <the third threshold density. That is, when the VOC concentration increases, the controller first suppresses the increase in the VOC concentration based on the drum rotation speed. When the increase in the VOC concentration cannot be suppressed only by adjusting the drum rotation speed, the controller adjusts the VOC concentration according to the flow rate of the high temperature gas or the amount of outside air introduced into the high temperature gas. By these controls of the controller, the VOC concentration contained in the high temperature gas is maintained below a predetermined concentration. When the VOC concentration does not decrease even by the above control, the controller opens the closing damper 13 and directly introduces the outside air into the housing 7. The first, second, and third threshold concentrations are appropriately set according to the size of the dryer 100 and the size and strength of each pipe.

  The advantages of the dryer 100 are organized. The dryer 100 is a drum type in which a solution is applied to the inner surface of the drum. As described above, since the gutter plate 24, the gas chamber 23, the scraper 20, the conveyor 22 and the like can be arranged inside the drum, the entire apparatus becomes compact. Since the hot gas blowing holes 23a are two-dimensionally arranged on the inner surface of the drum on which the solution is applied, the drying efficiency of the solution is good. In particular, the hot gas blown out flows along the inner surface of the drum on the inner side of the curved surface (the side where the center of the radius of curvature exists) and is not easily dissipated from the vicinity of the inner surface of the drum. It has become. The dryer 100 vaporizes VOC from the solution when the solution is dried. The dryer 100 circulates a hot gas for drying the solution. By providing the gas circulation path, the concentration of VOC contained in the hot gas is increased, that is, the energy density is increased, and the utility value of the hot gas in other equipment is increased.

  With reference to FIG. 5, the dryer 200 of 2nd Example is demonstrated. The dryer 200 is different from the dryer 100 of the first embodiment in the form of a gas chamber. Other parts are the same as those of the dryer 100 of the first embodiment. In FIG. 5, the same components as those in the dryer 100 of the first embodiment are denoted by the same reference numerals. The dryer 200 according to the second embodiment includes a plurality of small gas chambers 223. Each gas chamber 223 is supplied with high-temperature gas from the gas supply pipe 21. Each of the plurality of gas chambers 223 has a gas outlet that opens toward the inner surface of the drum 8 to which the solution is applied. The plurality of gas outlets (the plurality of gas chambers 223) are two-dimensionally arranged so as to face the partial inner surface of the inner surface of the drum 8 extending in the drum circumferential direction and the drum longitudinal direction. That is, the dryer 200 is the same as the dryer 100 of the first embodiment in the form of the hot gas blowing holes. Since the dryer 200 includes a plurality of small gas chambers 223, the utilization efficiency of the high temperature gas is better than that of the gas chamber 23 of the first embodiment.

  With reference to FIG. 6, the dryer 300 of 3rd Example is demonstrated. FIG. 6 is a diagram corresponding to FIG. 2 of the first embodiment. The dryer 300 is different from the dryers of the first and second embodiments in that it does not include a gas chamber. Other parts are the same as those of the dryer 100 of the first embodiment. In FIG. 6, the same components as those in the dryer 100 of the first embodiment are denoted by the same reference numerals. In the dryer 300 of the third embodiment, the gas supply pipe 321 opens toward the drum inner surface in the vicinity of the end surface of the drum 8. The hot gas blown out from the gas supply pipe 321 flows along the drum inner surface and then flows out from the opposite end of the drum as indicated by the arrow P in FIG. The dryer 300 has a simple structure as compared with the dryers of the first and second embodiments.

  With reference to FIG. 7, the dryer 400 of 4th Example is demonstrated. The dryer 400 differs from the dryers of the first and second embodiments in that the dryer 400 is not provided. Other parts are the same as those of the dryer 100 of the first embodiment. In FIG. 7, the same components as those in the dryer 100 of the first embodiment are denoted by the same reference numerals. The shape of the gas chamber 323 is the same as that of the gas chamber 23 of the first embodiment, but the arrangement is different from that of the first embodiment. However, the arrangement of the gas chamber 323 is such that a plurality of high-temperature gas blowing holes 323a are two-dimensionally arranged between the solution adhesion start position downstream in the drum rotation direction and the upstream of the scraper 20 in the drum rotation direction. This is the same as the gas chamber 23 of the first embodiment.

  In the dryer 400 of the fourth embodiment, a solution supply pipe 319 for supplying a solution to the inside of the drum 8 extends to the vicinity of the bottom of the drum 8 and opens. The solution A1 supplied from the solution supply pipe 319 accumulates at the bottom of the drum 8. The solution is blocked by the dam plates 8a (see FIG. 4) provided at both ends of the drum 8, and does not leak out of the drum 8. In FIG. 7, the drum 8 rotates counterclockwise. As the drum 8 rotates, the solution adheres to the inner surface of the drum (the solution to which the symbol A2 in FIG. 7 is attached). The solution adhering to the rotation of the drum 8 is dried and solidified, and the scraper 20 is scraped off from the drum inner surface. The dryer 400 of the fourth embodiment can store a large amount of solution in the drum 8 depending on the height of the weir plate 8a.

  Points to note about the dryer described in the examples are described. The solution supply pipes (19, 319) for supplying the solution into the drum correspond to an example of the solution supply means. In the case where the dryer has the slab 24, the slat 24 is also one of the components of the solution supply means.

  The gas supply pipes (21, 321) for supplying the high temperature gas into the drum correspond to an example of a heating means for heating and drying the solution. When the gas chamber (23, 223, 323) having the blowout holes for blowing the hot gas toward the drum inner surface is provided, the gas chamber is also a part of the heating means.

  The conveyor 22 according to the embodiment corresponds to an example of an unloading unit that receives the residue scraped off by the scraper 20 and unloads the residue from the drum. The dryer may include a belt type conveyor instead of the vibration type conveyor. Alternatively, the carry-out means may be a gutter that is inclined vertically downward toward the storage tank 50. If tilted vertically downward toward the storage tank 50, the fallen residue slides down to the storage tank 50 due to gravity.

  The dryer 100 of the first embodiment includes a gas chamber 23 having a plurality of blowout holes 23a. The opposing surface having the plurality of blowing holes 23a may be formed of a mesh plate. The mesh plate corresponds to a form in which an extremely large number of blowing holes 23a are provided. The mesh plate also functions as a rectifying plate that uniformly regulates the flow of hot gas blown toward the inner surface of the drum.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

2: Heater 3: Fan 4: Mixing valve 6: Gas reflux pipe 7: Housing 8: Drum 8a: Weir 12: Motor 13: Closing damper 14: Gas recovery pipe 16: Fan 17: Gas sensor 18: Solution supply amount adjustment valve 19, 319: Solution supply pipe 20: Scraper 21, 321: Gas supply pipe 22: Conveyor 23, 223, 323: Gas chamber 23a, 323a: Blow hole 24: Barbed plate 30: Circulation path 50: Storage tanks 100, 200, 300, 400: Drum-type dryer

Claims (8)

A hollow drum arranged sideways;
Driving means for rotating the drum;
Solution supply means for supplying a solution into the drum from the outside of the drum;
Heating means for heating and drying the solution adhering to the inner surface of the rotating drum;
A scraper that is in sliding contact with the inner surface of the drum and scrapes off the residue after drying of the solution adhering to the inner surface of the rotating drum;
An unloading means that extends along the scraper below the scraper and extends to the outside of the drum, and receives the residue scraped off by the scraper and unloads the drum.
A drum-type dryer comprising: The solution supply means includes
It includes a gutter extending along the drum axis and spaced from the drum inner surface,
2. The structure according to claim 1, wherein the solution is supplied to the upstream side of the drum plate in the drum rotation direction, and the solution uniformly adheres to the drum inner surface through the gap as the drum rotates. Drum dryer.   The heating means has a plurality of blowout holes for blowing high temperature gas toward the drum inner surface, and the plurality of blowout holes are partial inner surfaces extending in a drum circumferential direction and a drum longitudinal direction among the drum inner surfaces. The drum dryer according to claim 1, wherein the drum dryer is arranged two-dimensionally facing the drum.   The heating means includes a gas chamber disposed inside the drum and a gas supply means for supplying a high temperature gas into the gas chamber. The gas chamber includes a part of the drum inner surface in the drum circumferential direction and the drum length. The drum-type dryer according to claim 3, wherein the drum-type dryer has a facing surface facing a partial inner surface extending in a direction, and a plurality of blowout holes are provided two-dimensionally on the facing surface. The drum-type dryer according to any one of claims 1 to 4, wherein a solution containing a volatile organic compound (VOC) is dried.
The heating means includes a gas circulation path that collects and heats the high-temperature gas flowing out of the drum and blows it back into the drum, and also includes a mixing valve that mixes outside air with the circulating gas. Featured drum dryer. A gas sensor for measuring the VOC concentration in the drum;
6. The drum dryer according to claim 5, further comprising a controller that reduces the drum rotation speed when the VOC concentration measured by the gas sensor exceeds the first threshold concentration.   7. The drum dryer according to claim 6, wherein when the VOC concentration exceeds a second threshold concentration higher than the first threshold concentration, the controller reduces the flow rate of the hot gas blown into the drum. .   The controller adjusts the opening degree of the mixing valve so as to increase the amount of outside air mixed with the circulating high-temperature gas when the VOC concentration exceeds a third threshold concentration higher than the first threshold concentration. A drum dryer according to claim 6 or 7.

Images