JP6709258B2 - Dryer - Google Patents

Description

Embodiments of the present invention relate to a drying device.

2. Description of the Related Art As a conventional drying device, there is a gas ejection type drying device that ejects a drying gas at a high speed to collide with an object to be dried to dry the object to be dried. In such a gas jet type drying device, the heat transfer can be improved by causing the drying gas to vertically collide with the material to be dried at a high speed. As the drying gas, for example, a high temperature gas is used.

The gas jet type drying device includes a plurality of jet nozzles for jetting a drying gas. This ejection nozzle is configured by forming a plurality of ejection holes on the side wall of a cylindrical ejection duct, for example.

In such a conventional gas jet type drying device, the drying gas is introduced into a wide space in the blowing duct after the flow rate is adjusted. Then, the drying gas introduced into the wide space in the blowing duct is ejected from the ejection nozzle toward the object to be dried.

Here, as the drying device, there is a rotary drying device that blows a drying gas onto an object to be dried installed on a rotary plate that rotates about a transport rotation axis to dry the object to be dried.

FIG. 9: is the figure which showed the outline of the conventional rotary type drying device 300 as a partial cross section. 10: is a figure which shows the XX cross section of FIG.

As shown in FIG. 9, the drying device 300 includes a combustion chamber 310 and a drying chamber 330 for drying the material W to be dried with the drying gas discharged from the combustion chamber 310. The drying device 300 is a circulation type drying device that introduces the combustion gas generated in the combustion chamber 310 into the drying chamber 330 and returns a part of the combustion gas introduced into the drying chamber 330 to the combustion chamber 310.

The drying chamber 330 includes a tubular casing 331, and as shown in FIG. 10, a plurality of stages are installed in the vertical direction. The casing 331 constitutes the outer shell of the drying chamber 330. The casing 331 is extended in the vertical direction. In each drying chamber 330, a drying space 332 is provided inside a casing 331.

As shown in FIG. 9, the casing 331 has a carry-in/carry-in port 334 for arranging the article to be dried W at a predetermined position in the drying chamber 330 and taking out the article to be dried W from the drying chamber 330. Has been formed. Further, the casing 331 is provided with a slide door 335 for opening and closing the loading/unloading port 334.

The slide door 335 is opened, and the dried material W is taken out of the drying chamber 330 via the carry-in/carry-in port 334, or the dried material W is placed in the drying chamber 330 to be dried.

Further, the casing 331 is connected to a return pipe 336 that sucks the drying gas in the drying chamber 330 that circulates in the combustion chamber 310.

The drying chamber 330 further includes a transfer device 340 and a gas ejection unit 350.

The transport device 340 rotatably transports the material W to be dried around the gas ejection unit 350. The transport device 340 includes a rotary plate 341 on which the material to be dried W is arranged, and a drive mechanism (not shown) that rotationally drives the rotary plate 341.

The rotating plate 341 is configured to be rotatable between the gas ejection portion 350 and the casing 331 in the circumferential direction of the gas ejection portion 350, for example, clockwise in the cross section of FIG. 9. As a result, the material to be dried W placed on the rotary plate 341 is rotatably transported around the gas ejection portion 350.

As shown in FIGS. 9 and 10, the gas ejection unit 350 includes an outer cylinder 351, an inner cylinder 352, a partition plate 353, and a drying gas ejection nozzle 354.

The outer cylinder 351 is provided inside the casing 331, and the casing 331 and the outer cylinder 351 form a double pipe structure. An inner cylinder 352 is provided inside the outer cylinder 351, and the outer cylinder 351 and the inner cylinder 352 form a double pipe structure. An opening 355 is formed in the inner cylinder 352.

Upper ends of the outer cylinder 351 and the inner cylinder 352 are closed by a lid member 333 of the casing 331. An introduction pipe 380 is connected to the lid member 333 so as to communicate with the inside of the inner cylinder 352.

As shown in FIG. 10, the partition plate 353 axially partitions the outer cylinder 351 and the inner cylinder 352. Then, an annular space 356 surrounded by the inner cylinder 352, the partition plate 353 and the outer cylinder 351 is formed.

The drying gas ejection nozzle 354 projects from the outer peripheral surface 351a of the outer cylinder 351 toward the transport path. Further, the drying gas ejection nozzles 354 are arranged at a predetermined interval in the circumferential direction of the outer peripheral surface 351a of the outer cylinder 351. As shown in FIG. 9, the drying gas ejection nozzle 354 is arranged within a predetermined circumferential range of the outer cylinder 351.

In the above-described drying device 300, when combustion in the burner 311 starts, the drying gas (combustion gas) in the burner 311 is sucked into the introduction pipe 380 by suction of the circulation fan 381. The drying gas sucked into the introduction pipe 380 is introduced into the inner cylinder 352 of the drying chamber 330.

The drying gas introduced into the inner cylinder 352 spreads to the space 356 through the opening 355 and is jetted from the drying gas jet nozzle 354 to the drying space 332. A part of the drying gas sucked into the introduction pipe 380 is discharged into the atmosphere via the branch pipe 382.

The drying gas ejected from the drying gas ejection nozzle 354 heats the article W to be dried that is rotatably conveyed and spreads in the drying space 332. At that time, a part of the drying gas is guided to the combustion chamber 310 through the return pipe 336.

The dried article W is taken out by opening the slide door 335. Then, after the dried material to be dried W is taken out, the undried material to be dried W is placed on the rotary plate 341. Meanwhile, the slide door 335 is in an open state.

In such a drying device 300, the temperature of the drying gas in the drying space 332 is kept uniform in order to uniformly and appropriately dry the material W to be dried.

Japanese Patent Laid-Open No. 11-63828

As described above, in the conventional circulation type drying device 300, a part of the drying gas is introduced into the combustion chamber 310 through the return pipe 336. Due to the suction flow through the return pipe 336, outside air is drawn into the drying space 332 when the slide door 335 is opened.

As a result, the temperature of the drying gas in a part of the drying space 332 may decrease. The non-uniform distribution of the temperature of the drying gas in the drying space 332 hinders the proper drying of the material W to be dried.

The problem to be solved by the present invention is to provide a drying device capable of maintaining a uniform temperature distribution of a drying gas in a drying space even when a material to be dried is taken in and out.

The drying device according to the embodiment ejects the drying gas generated by the drying gas generation device toward the object to be dried that is rotatably conveyed to dry the object to be dried. This drying device includes a tubular casing, a tubular body provided in the casing, into which a drying gas generated by the dry gas generating device is introduced, and the tubular body between the casing and the tubular body. A rotary plate having an annular flat plate shape, which is rotatable around the central axis of the body and is provided in a plurality of stages in the central axis direction of the cylindrical body, and in which the object to be dried is arranged, and the casing. And a loading/unloading port for loading and unloading the material to be dried, which is provided on the outer periphery of the cylindrical body and is rotatably conveyed in a drying space surrounded by the casing, the cylindrical body, and the rotating plate. A plurality of drying gas ejection nozzles for ejecting the drying gas introduced into the cylinder toward an object, and a part of the drying gas in the drying space, which is connected to the casing, is guided to the drying gas generator. A return pipe and a hot air jet pipe that is connected to the casing and jets a part of the drying gas generated by the dry gas generator into the drying space.

Further, in the drying device, an imaginary straight line connecting the center of the transport rotation axis and the center of the carry-in/carry-out port in the circumferential direction is defined as L, and the upstream side of the drying gas ejection nozzle arranged on the most upstream side in the transport rotation direction. When an imaginary straight line connecting the side end of the imaginary line and the center of the transport rotation axis is M, an angle a formed from the imaginary straight line L to the imaginary straight line M in the transport rotation direction is 35 degrees or more and 90 degrees or less. When a virtual straight line that connects the downstream side end of the drying gas ejection nozzle arranged on the most downstream side in the rotation direction and the center of the transport rotation axis is N, the virtual straight line M extends from the virtual straight line M in the transport rotation direction. An angle b formed by the straight line N is 135 degrees or more and 270 degrees or less, and when an imaginary straight line connecting the center of the return pipe in the circumferential direction at the connection position with the casing and the center of the transport rotation axis is P1. The angle d1 between the virtual straight line L and the virtual straight line P1 in the direction opposite to the transport rotation direction is 45 degrees or more and 225 degrees or less, or 315 degrees or more and less than 360 degrees, and the hot air jet pipe at the connection position with the casing. When an imaginary straight line connecting the center of the circumferential direction with the center of the transport rotation axis is Q1, the angle e1 formed from the imaginary straight line L to the imaginary straight line Q1 in the reverse transport rotation direction is greater than 0 degree and 50 degrees. It is the following.

According to the drying apparatus of the present invention, it is possible to maintain a uniform temperature distribution of the drying gas in the drying space even when the material to be dried is taken in and out.

It is the figure which showed the outline of the drying device of 1st Embodiment as a partial cross section. It is a figure which shows the AA cross section of FIG. It is the figure which showed the outline of the drying apparatus of 2nd Embodiment typically. It is the figure which simplified and showed the structure of the analysis model A typically. It is a top view when the drying gas ejection nozzle provided in the outer cylinder is seen from the front. 6 is a diagram showing the evaluation result of the temperature distribution of the drying gas in the drying space in the analytical model A. FIG. It is the figure which simplified and showed the structure of the analysis model B typically. FIG. 8 is a diagram showing an evaluation result of a temperature distribution of a drying gas in a drying space in the analysis model B. It is the figure which showed the outline of the conventional rotary type drying device as a partial cross section. It is a figure which shows the XX cross section of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a partial cross-sectional view showing an outline of a drying device 10 according to the first embodiment. FIG. 2 is a diagram showing a cross section taken along the line AA of FIG.

As shown in FIG. 1, the drying device 10 includes a combustion chamber 20 and a drying chamber 50 that dries the article W to be dried with the drying gas discharged from the combustion chamber 20. The drying device 10 is a circulation type drying device that introduces the combustion gas generated in the combustion chamber 20 into the drying chamber 50 and returns a part of the combustion gas introduced into the drying chamber 50 to the combustion chamber 20.

The combustion chamber 20 is a housing having an internal space. A burner 30 is provided at one end 20a of the combustion chamber 20. The burner 30 includes a fuel supply system 31 that supplies fuel and an air supply system 32 that supplies air. Here, an example is shown in which the air supply system 32 is provided with the intake fan 32a.

In the burner 30, the combustion gas generated by burning the fuel supplied from the fuel supply system 31 and the air supplied from the air supply system 32 spreads inside the combustion chamber 20. This combustion gas functions as a drying gas for drying the material to be dried W.

The other end 20b of the combustion chamber 20 has an outlet opening (not shown) for discharging the internal combustion gas. Further, on the other end 20b side in the combustion chamber 20, for example, as shown in FIG. 1, a filter 21 is provided over the cross section. The filter 21 removes foreign matter in the combustion gas flowing toward the outlet opening.

The drying chamber 50 dries the article to be dried W with the drying gas discharged from the combustion chamber 20. In the drying chamber 50, the material W to be dried is rotatably conveyed and dried.

As shown in FIG. 1, a plurality of drying chambers 50 are installed in a cylindrical casing 51 in the vertical direction (vertical direction). The casing 51 constitutes, for example, the outer shell of the drying chamber 50. The casing 51 extends in the vertical direction. In each drying chamber 50, a drying space 53 is provided inside the casing 51.

As shown in FIG. 1, the casing 51 has a cross section perpendicular to the central axis direction of the casing 51 (hereinafter referred to as a horizontal cross section), for example, formed in a circular shape. The shape of the horizontal cross section of the casing 51 is not limited to a circle, and may be a polygon. Further, the central axis direction of the casing 51 is the vertical direction.

As shown in FIG. 1, the casing 51 has a carry-in/carry-out port 54 for arranging the article to be dried W at a predetermined position in the drying chamber 50 and for taking out the article to be dried W from the drying chamber 50. Has been formed. The carry-in/carry-in port 54 is formed, for example, at the center of the casing 51 in the drying chamber 50 in the height direction (vertical direction).

Further, the casing 51 is provided with a slide door 55 for opening and closing the loading/unloading port 54. The slide door 55 is configured to be slidable in the horizontal direction. The slide door 55 is opened, and the dried material W is taken out of the drying chamber 50 via the carry-in/carry-in port 54 or is placed in the drying chamber 50 to be dried.

The carry-in/carry-in port 54 and the slide door 55 are provided for each of the drying chambers 50.

The drying chamber 50 further includes a transfer device 60 and a gas ejection unit 70. Further, the drying chamber 50 is connected to the introduction pipe 100, the return pipe 101, and the hot air jet pipe 102.

The transport device 60 rotationally transports the material W to be dried around the gas ejection portion 70. The transport device 60 includes a rotary plate 61 on which the material to be dried W is arranged, and a drive mechanism (not shown) that rotationally drives the rotary plate 61.

As shown in FIG. 2, the rotary plates 61 of the respective stages are fixed in parallel with each other at regular intervals in the vertical direction (vertical direction). The upper and lower rotating plates 61 are fixed in parallel with each other by a supporting member (not shown). Then, when the lowermost rotary plate 61 is rotated by the power of, for example, a drive motor (not shown) that is a drive mechanism, the rotary plates 61 of the respective stages are simultaneously rotated accordingly.

The rotary plate 61 is configured to be rotatable between the gas ejection portion 70 and the casing 51 in the circumferential direction of the gas ejection portion 70, for example, clockwise. As a result, the material to be dried W placed on the rotating plate 61 is rotatably conveyed around the gas ejection portion 70.

The annular space surrounded by the rotating plates 61 arranged in the up-down direction and between the casing 51 and the gas ejection portion 70 is a space that constitutes a transport path and functions as a drying space 53. The drying space 53 is an area for drying the article to be dried W moved by the transport device 60.

In the drying space 53, it is preferable that the entire drying space 53 is maintained at a uniform temperature even when the slide door 55 is opened. Further, even in the state where the slide door 55 is opened in the drying space 53, a uniform temperature is maintained at least in a region provided with the drying gas ejection nozzle 74 that gives a sufficient amount of heat to the object to be dried W. Is preferred.

As shown in FIGS. 1 and 2, the gas ejection unit 70 includes an outer cylinder 71, an inner cylinder 72, a partition plate 73, and a drying gas ejection nozzle 74.

The outer cylinder 71 is a cylindrical casing having an outer peripheral surface 71a along the transport direction of the article to be dried W. The outer cylinder 71 extends inside the casing 51 along the central axis direction of the casing 51. The casing 51 and the outer cylinder 71 form a double pipe structure.

The gap between the casing 51 and the outer cylinder 71 is uniform in the circumferential direction. Moreover, the casing 51 and the outer cylinder 71 have a central axis concentrically.

An inner cylinder 72 is provided inside the outer cylinder 71. The inner cylinder 72 is formed of a cylindrical body, and extends inside the outer cylinder 71 along the central axis direction of the casing 51. The outer cylinder 71 and the inner cylinder 72 form a double pipe structure.

The gap between the inner cylinder 72 and the outer cylinder 71 is uniform in the circumferential direction. The inner cylinder 72 and the outer cylinder 71 have concentric center axes.

That is, the casing 51, the outer cylinder 71, and the inner cylinder 72 form a triple pipe structure. Further, the casing 51, the outer cylinder 71, and the inner cylinder 72 have concentric center axes. Therefore, in the following, these central axis directions are simply referred to as axial directions. The axial direction is the vertical direction.

Upper ends of the outer cylinder 71 and the inner cylinder 72 are closed by a lid member 52 of the casing 51. An introduction pipe 100, which will be described later, is connected to the lid member 52 so as to communicate with the inside of the inner cylinder 72. In other words, the introduction pipe 100 is connected to the lid member 52 so as to introduce the drying gas into the second space 76 described later.

The inner cylinder 72 divides the inner space of the outer cylinder 71 into a first space 75 on the transport path side (rotating plate 61 side) of the article to be dried W and a second space 76 on the side different from the transport path side. .. That is, the first space 75 is an annular space formed between the outer cylinder 71 and the inner cylinder 72. The second space 76 is a space inside the inner cylinder 72.

The inner cylinder 72 is formed with a plurality of openings 77 that allow the first space 75 and the second space 76 to communicate with each other. A plurality of openings 77 are formed in the axial direction. The openings 77 are formed corresponding to the plurality of drying chambers 50 installed in the vertical direction. That is, one opening 77 is formed for one drying chamber 50.

The drying gas introduced into the second space 76 flows into the first space 75 through this opening 77.

The partition plate 73 is configured by an annular flat plate member. As shown in FIG. 2, the partition plate 73 partitions the first space 75 between the outer cylinder 71 and the inner cylinder 72 in the axial direction. For example, the partition plate 73 is horizontally connected between the outer cylinder 71 and the inner cylinder 72. Then, the first space 75 partitioned by the partition plate 73 constitutes an individual space 78.

That is, the individual space 78 is an annular space surrounded by the inner cylinder 72, the partition plate 73, and the outer cylinder 71.

For example, an individual space 78 is formed for each of the openings 77 formed in the inner cylinder 72. In other words, one individual space 78 is formed for one opening 77. The opening 77 is formed, for example, at a position where the drying gas that has passed through the opening 77 can be uniformly expanded into the individual space 78. For example, the opening 77 is formed, for example, in the axial center of the inner cylinder 72.

Here, in order to make the flow rate of the drying gas introduced into each individual space 78 constant, for example, an opening adjustment unit 80 may be provided. FIG. 1 and FIG. 2 exemplify a configuration including the opening adjustment unit 80.

The opening adjustment unit 80 adjusts the opening of the opening 77 of the inner cylinder 72, and adjusts the flow rate of the drying gas flowing from the second space 76 into the individual space 78. The opening adjustment unit 80 includes a slide member 81 and a support member 82, as shown in FIGS. 1 and 2, for example.

The slide member 81 is, for example, a plate-like member that is curved along the outer peripheral surface 72a of the inner cylinder 72. The slide member 81 has a size larger than that of the opening 77. Therefore, the slide member 81 can also close the opening 77.

The support member 82 slidably supports the slide member 81. The support member 82 is horizontally provided along the outer peripheral surface 72a of the inner cylinder 72, for example. That is, the support member 82 is curved and provided horizontally along the outer peripheral surface 72a.

The support member 82 is composed of a rail-shaped member that supports the slide member 81 from above and below. That is, the support member 82 is configured by including a pair of curved rod-shaped bending members at positions above and below the opening 77.

Then, the opening of the opening 77 can be adjusted by sliding the slide member 81 in the circumferential direction.

For example, when the opening adjustment unit 80 is provided, the opening of each opening 77 is adjusted so that the flow rate of the drying gas flowing into each individual space 78 becomes uniform.

The drying gas ejection nozzle 74 is provided so as to project from the outer peripheral surface 71 a of the outer cylinder 71 toward the transport path. The drying gas ejection nozzle 74 communicates with the individual space 78 and ejects the drying gas in the individual space 78 to the drying space 53 (transport path side). The drying gas ejection nozzles 74 are arranged at a predetermined interval in the circumferential direction of the outer peripheral surface 71 a of the outer cylinder 71.

Here, the drying gas jet nozzle 74 is arranged within a predetermined circumferential range of the outer cylinder 71, as shown in FIG. The drying gas ejection nozzle 74 is arranged, for example, from the downstream side of the position facing the carry-in/carry-in port 54 in the transport rotation direction (the solid line arrow in FIG. 1 ). The transport rotation direction is a direction in which the rotary plate 61 (the object to be dried W) is rotated about the transport rotation axis center O.

Specifically, for example, as shown in FIG. 1, a virtual straight line connecting the transport rotation axis center O and the circumferential center of the carry-in/carry-in port 54 is defined as L, and drying is arranged on the most upstream side in the transport rotation direction. An imaginary straight line connecting the upstream side end of the for-use gas ejection nozzle 74 and the transport rotation axis center O is defined as M. The angle between the virtual straight line L and the virtual straight line M in the transport rotation direction (clockwise direction in FIG. 1) is defined as a.

In this case, the angle a formed by the virtual straight line L and the virtual straight line M is preferably 35 degrees or more.

That is, on the outer peripheral surface 71a of the outer cylinder 71, at a position forming an angle a in the transport rotation direction from a position intersecting with the imaginary straight line L, on the upstream side of the drying gas ejection nozzle 74 arranged on the most upstream side in the transport rotation direction. The side edge is located.

By setting the angle a to 45 degrees or more, the drying gas ejected from the drying gas ejection nozzle 74 arranged on the most upstream side in the transport rotation direction is carried out when the slide door 55 is opened. It can be prevented from directly flowing out from the carry-in port 54.

Here, the angle a is preferably 90 degrees or less. When the angle a exceeds 90 degrees, the range in which the drying gas ejection nozzle 74 is not provided becomes wider from the virtual straight line L toward the transport rotation direction. Therefore, it becomes impossible to appropriately dry the material W to be dried during one round of the drying space 53. Further, the angle a is more preferably 35 degrees or more and 60 degrees or less.

Further, an imaginary straight line connecting the downstream side end of the drying gas ejection nozzle 74 arranged on the most downstream side in the transport rotation direction and the transport rotation axis center O is N. The angle formed by the above-described virtual straight line M and the virtual straight line N in the transport rotation direction is defined as b.

In this case, the angle b formed by the virtual straight line M and the virtual straight line N is preferably 135 degrees or more and 270 degrees or less. The drying gas ejection nozzle 74 is arranged within the range of the angle b.

By arranging the drying gas ejection nozzle 74 in this range, it is possible to sufficiently supply the amount of heat required for drying the object to be dried W. Further, by disposing the drying gas jet nozzle 74 in this range, the temperature in the heating zone in the drying space 53 where the drying gas is heated by spraying the drying gas on the article to be dried W can be maintained at an appropriate and uniform temperature. .. Furthermore, it is possible to make the temperature uniform while maintaining the temperature of the drying space 53 other than the heating zone at an appropriate temperature.

Here, the temperature in the heating zone and the drying space 53 from the heating zone to the region where the hot air jet tube 102 is provided has a difference from the temperature of the drying gas jetted from the drying gas jet nozzle 74, For example, it is preferably maintained within the range of 15°C.

The angle b is set based on, for example, the heat capacity of the material to be dried W, the flow rate and flow velocity of the drying gas ejected from one drying gas ejection nozzle 74, the time for which the drying space 53 makes one revolution, and the like. .

Here, the opening 77 of the inner cylinder 72 described above is formed at a position facing the inner peripheral surface of the outer cylinder 71 in a range excluding a predetermined circumferential range in which the drying gas ejection nozzle 74 is arranged.

In the cross section of the drying chamber 50 shown in FIG. 1, for example, the opening 77 of the inner cylinder 72 has an inner cylinder 72 within the range of the angle c on the side different from the angle b in the angle formed by the virtual straight line M and the virtual straight line N. Is formed.

The end of the opening 77 on the upstream side in the transport rotation direction and the end of the opening 77 on the downstream side in the transport rotation direction are located within the range of the angle c described above.

For example, the opening 77 of the inner cylinder 72 has the drying gas spouting nozzles 74 arranged in the circumferential direction, the transporting rotation direction from the central axis of the drying gas spouting nozzle 74 located at the center to the transport rotation axis center O. It is preferably formed at a position facing the inner peripheral surface of the outer cylinder 71, which is shifted by 180 degrees. In this case, for example, the opening 77 is formed such that the center of the circumferential length of the opening 77 is located at a position facing the inner circumferential surface that is offset by 180 degrees.

As a result, the drying gas flowing from the second space 76 into the individual space 78 through the opening 77 does not directly flow into the drying gas jet nozzle 74.

That is, the drying gas flowing into the individual space 78 through the opening 77 collides with the inner peripheral surface of the outer cylinder 71 and spreads in the circumferential direction. At this time, the drying gas that has collided with the inner peripheral surface of the outer cylinder 71 spreads in the transport rotation direction and in the direction opposite to the transport rotation direction, as indicated by the dashed arrow in FIG.

As a result, a flow of the drying gas that spreads throughout the individual space 78 is formed, and the drying gas uniformly spreads in the individual space 78.

Further, as shown in FIG. 2, the drying gas ejection nozzles 74 are arranged, for example, in a plurality of stages at predetermined intervals in the axial direction. Further, the drying gas ejection nozzles 74 in each stage are arranged at a predetermined interval in the circumferential direction of the outer peripheral surface 71a of the outer cylinder 71, as described above. The number of axial stages provided with the drying gas ejection nozzle 74 is not particularly limited and is set appropriately.

Here, in order to improve the heat transfer between the drying gas ejected from the drying gas ejection nozzle 74 and the article to be dried W, for example, the article W to be dried is conveyed to the drying gas ejection nozzle 74. It is preferably arranged so as to be perpendicular to the direction. That is, it is preferable that the drying gas jet nozzle 74 is arranged so that the jetting drying gas collides vertically with the object W to be dried.

Therefore, for example, in the cross section of the drying chamber 50 shown in FIG. 1, the drying gas ejection nozzles 74 are arranged so that their central axes are located on a line extending radially from the transport rotation axis center O.

Here, in order to improve the heat transfer coefficient, the flow of the drying gas ejected from the drying gas ejecting nozzle 74 is preferably a jet which does not easily spread to the outside after being ejected and collides with the material to be dried W at a high speed. .. Therefore, the drying gas ejection nozzle 74 is formed of, for example, a tubular pipe or the like that easily forms such a jet flow. As the tubular tube, for example, a tube having a rectangular sectional shape perpendicular to the central axis of the tubular tube, or a tube having a circular sectional shape perpendicular to the central axis of the tubular tube is used.

As described above, one end of the introduction pipe 100 is connected to the lid member 52 so as to communicate with the inside of the inner cylinder 72.

The other end of the introduction pipe 100 is connected to an outlet opening (not shown) of the combustion chamber 20. Into the introduction pipe 100, a drying gas is introduced from the combustion chamber 20 into the inner cylinder 72 of the gas ejection unit 70 via the introduction pipe 100, and from the drying chamber 50 to the combustion chamber 20 via a return pipe 101 described later. A circulation fan 110 is interposed to return the drying gas.

In the circulation fan 110, for example, by controlling the fan motor 111 to adjust the fan rotation speed, the flow rate of the drying gas supplied to the gas ejection unit 70 is adjusted. Thereby, the speed (flow rate) of the drying gas ejected from the drying gas ejection nozzle 74 is adjusted. The circulation fan 110 is composed of, for example, a sirocco fan or a turbo fan.

The introduction pipe 100 is branched downstream of the outlet of the circulation fan 110 to form a branch pipe 105. The branch pipe 105 is connected to a hot air jet pipe 102 described later. The introduction pipe 100 is further branched at the downstream side of the branch portion to the branch pipe 105 to form a branch pipe 103.

The branch pipe 103 discharges a part of the drying gas flowing through the introduction pipe 100 into the atmosphere. The branch pipe 103 is provided with a flow rate adjusting unit 104 for adjusting the flow rate of the drying gas to be exhausted. The flow rate adjusting unit 104 is composed of, for example, a damper. The opening of the damper is adjusted so that a constant flow rate of the drying gas is discharged into the atmosphere.

Next, the connection position of the return pipe 101 with the casing 51 will be described.

The return pipe 101 communicates the drying space 53 of the drying chamber 50 with the combustion chamber 20. As shown in FIG. 1, one end of the return pipe 101 is connected to the casing 51 so as to communicate with the drying space 53 of the drying chamber 50. The return pipe 101 is formed, for example, at the center in the height direction (vertical direction) of the casing 51 in the drying chamber 50. The return pipe 101 is provided in each drying chamber 50.

As shown in FIG. 1, the other end of the return pipe 101 branches from the return pipe 101 to form a branch pipe 106. One end of the branch pipe 106 is open to the atmosphere, for example. The branch pipe 106 is a pipe for introducing the atmosphere (air) into the drying gas that returns from the drying chamber 50 to the combustion chamber 20 via the return pipe 101. That is, the atmospheric air is sucked from the end of the branch pipe 106 on the atmospheric opening side and introduced into the return pipe 101.

The branch pipe 106 is provided with a flow rate adjusting unit 107 for adjusting the flow rate of air introduced into the return pipe 101. The flow rate adjusting unit 107 is composed of, for example, a damper. The opening of the damper is adjusted so that a constant flow rate of air is introduced into the return pipe 101, for example.

The other end of the return pipe 101 is connected to the side wall of the combustion chamber 20. The side wall position to which the other end of the return pipe 101 is connected is, for example, as shown in FIG. 1, between the filter 21 and the burner 30 in the direction from the one end 20a side to the other end 20b side of the combustion chamber 20. Is set as follows. As a result, the drying gas circulated in the combustion chamber 20 through the return pipe 101 passes through the filter 21 when being introduced into the introduction pipe 100 from the combustion chamber 20 again. As a result, foreign matter in the circulated drying gas is removed.

Here, as shown in FIG. 1, a virtual straight line connecting the center of the return pipe 101 in the circumferential direction at the connection position with the casing 51 and the transport rotation axis center O is designated as P1. An angle between the virtual straight line L and the virtual straight line P1 in the direction opposite to the transport rotation direction (hereinafter, referred to as the transport rotation reverse direction) is d1. The reverse direction of the transport rotation is the counterclockwise direction in FIG.

In this case, the angle d1 formed by the virtual straight line L and the virtual straight line P1 is preferably 45 degrees or more and 225 degrees or less, or 315 degrees or more and less than 360 degrees. That is, the center in the circumferential direction of the return pipe 101 at the connection position with the casing 51 is within the range of 45 degrees or more and 225 degrees or less, or 315 degrees or more from the circumferential center of the carry-in/carry-in port 54 in the reverse transport rotation direction. It is located within a range smaller than 360 degrees.

When the angle d1 is close to 360 degrees, the connection position of the return pipe 101 with the casing 51 is set in view of the relationship with the position of the carry-in/carry-out port 54, and in terms of production and function. That is, when the angle d1 is close to 360 degrees, the return pipe 101 is connected to a position as close as possible to the carry-in/carry-out port 54 within a range in which the function of the carry-in/carry-out port 54 is not impaired and a structurally possible range.

By setting the angle d1 within the above range, the temperature of the drying space 53 can be maintained at an appropriate temperature and even when the slide door 55 is open. Even when the slide door 55 is open, it is possible to prevent external air from flowing into the drying space 53 from the carry-in/carry-in port 54 due to suction in the return pipe 101, for example. Further, even when the outside air flows into the drying space 53 through the carry-in/carry-in port 54 in the state where the slide door 55 is opened, the influence on the temperature distribution of the air is suppressed, and the temperature of the drying space 53 is adjusted to an appropriate temperature. And can be maintained uniform.

Here, when the air flowing into the drying space 53 from the carry-in/carry-in port 54 is directly sucked into the return pipe 101 along the inner peripheral surface of the casing 51 and guided to the combustion chamber 20, the temperature of the drying gas in the combustion chamber 20 is increased. Is reduced. In this case, the output of the burner 30 is increased in order to keep the temperature of the drying gas in the combustion chamber 20 constant. Therefore, the fuel consumption increases.

However, when the angle d1 is in the range of 45 degrees or more and 225 degrees or less, it is possible to prevent the air flowing into the drying space 53 from the carry-in/carry-in port 54 from being directly sucked by the return pipe 101 along the inner peripheral surface of the casing 51. Therefore, it is possible to prevent the temperature of the drying gas in the combustion chamber 20 from decreasing due to the drying gas returned to the combustion chamber 20. This suppresses an increase in fuel consumption in the burner 30.

Here, the angle d1 is more preferably 90 degrees or more and 135 degrees or less. In this case, the flow rate of the external air drawn into the drying space 53 from the carry-in/carry-in port 54 by the suction of the return pipe 101 can be further suppressed.

The return pipe 101 is composed of, for example, a tubular pipe or the like. As the tubular tube, for example, a tube having a rectangular sectional shape perpendicular to the central axis of the tubular tube, or a tube having a circular sectional shape perpendicular to the central axis of the tubular tube is used.

Next, the connection position of the hot air jet pipe 102 with the casing 51 will be described.

The hot air jet pipe 102 jets a drying gas from the casing 51 side to the drying space 53. As shown in FIG. 1, the hot air jet pipe 102 is connected to the casing 51 so as to communicate with the drying space 53 of the drying chamber 50. The hot-air jet pipe 102 is formed, for example, in the axial center of the casing 51 in the drying chamber 50. The hot air jet pipes 102 are provided in each of the drying chambers 50.

A branch pipe 105 branched from the introduction pipe 100 is connected to the hot air jet pipe 102. The branch pipe 105 is provided with a flow rate adjusting unit 108 for adjusting the flow rate of the drying gas ejected into the drying space 53.

The branch pipe 105 is branched on the circulation fan 110 side with respect to the branch pipe 103, but may be branched on the downstream side (gas ejection portion 70 side) with respect to the branch point where the branch pipe 103 is branched.

The number of hot air jetting pipes 102 connected to the casing 51 may be one or two or more. When two or more hot air ejection pipes 102 are provided, the hot air ejection pipes 102 are, for example, arranged at equal intervals in the axial direction.

When two or more hot air jet pipes 102 are provided, for example, the downstream end of the branch pipe 105 branches corresponding to each hot air jet pipe 102, and this branch pipe is connected to each hot air jet pipe 102. When two or more hot air jet pipes 102 are provided, a buffer portion forming a buffer space may be provided at the downstream end of the branch pipe 105, and the upstream end portion of each hot air jet pipe 102 may be connected to this buffer portion.

Here, as shown in FIG. 1, a virtual straight line connecting the circumferential center of the hot air blast pipe 102 at the connection position with the casing 51 and the transport rotation axis center O is designated as Q1. The angle formed by the imaginary straight line L and the imaginary straight line Q1 in the direction opposite to the transport rotation is e1.

In this case, it is preferable that the angle e1 formed by the virtual straight line L and the virtual straight line Q1 is larger than 0 degree and 50 degrees or less. That is, the center in the circumferential direction of the hot-air jetting pipe 102 at the connection position with the casing 51 is located within the range of more than 0 degrees and not more than 50 degrees in the opposite transport rotation direction from the center of the carry-in/out port 54 in the circumferential direction. .

When the angle e1 is close to 0 degrees, the connection position of the hot air jet pipe 102 with the casing 51 is set in view of the relationship with the position of the carry-in/carry-out port 54, and from the viewpoint of production and function. That is, when the angle e1 is close to 0 degree, the hot-air jetting pipe 102 is connected to a position as close as possible to the carry-in/carry-out port 54 within a range that does not impair the function of the carry-in/carry-out port 54 and within a structurally possible range.

Further, the connection position of the hot air jet pipe 102 with the casing 51 is set so as not to overlap the connection position of the return pipe 101 with the casing 51.

By setting the angle e1 in the above range, the drying gas is jetted from the hot air jet pipe 102 even when the outside air flows into the drying space 53 from the loading/unloading port 54 in the state where the slide door 55 is opened. As a result, it is possible to prevent the inflow of air in the direction opposite to the transport rotation direction from the position where the hot air jet pipe 102 is provided. Here, the angle e1 is more preferably 25 degrees or more and 45 degrees or less.

As described above, the flow of the drying gas ejected from the hot air ejection pipe 102 is, for example, in order to prevent the outside air from flowing in the direction opposite to the conveying rotation direction from the ejection position of the drying gas in the hot air ejection pipe 102. It is preferable that the jet flow is a high-speed jet that does not easily spread outward after being jetted.

Therefore, the hot air jet pipe 102 is formed of, for example, a tubular pipe or the like, which easily forms such a jet flow. As the tubular tube, for example, a tube having a rectangular sectional shape perpendicular to the central axis of the tubular tube, or a tube having a circular sectional shape perpendicular to the central axis of the tubular tube is used.

Next, the operation of the drying device 10 will be described.

At the start of operation of the drying device 10, the intake fan 32a and the circulation fan 110 are driven.

When combustion in the burner 30 starts, the drying gas (combustion gas) in the burner 30 is sucked into the introduction pipe 100 by the suction of the circulation fan 110. The drying gas sucked into the introduction pipe 100 is introduced into the gas ejection portion 70 of the drying chamber 50.

Here, a part of the drying gas sucked into the introduction pipe 100 passes through the branch pipe 105 and is guided to the hot air jet pipe 102. Further, another part of the drying gas sucked into the introduction pipe 100 is discharged into the atmosphere through the branch pipe 103.

The drying gas introduced into the second space 76 through the introduction pipe 100 spreads in the second space 76. Then, the drying gas that has spread in the second space 76 flows into each individual space 78 from the opening 77 of the inner cylinder 72. At this time, the flow rate of the drying gas flowing into each individual space 78 is adjusted to be uniform by the opening adjustment unit 80, for example.

The drying gas flowing into the individual space 78 collides with the inner peripheral surface of the outer cylinder 71 and spreads uniformly in the transport rotation direction and the transport rotation reverse direction, as indicated by the dashed arrow in FIG. 1. Then, the drying gas that has spread into the individual space 78 is jetted from the drying gas jet nozzle 74 to the drying space 53.

At this time, the pressure of the drying gas in the individual space 78 becomes substantially uniform. Then, the flow velocity of the drying gas ejected from each of the drying gas ejection nozzles 74 becomes substantially equal.

The drying gas ejected into the drying space 53 collides with the article W to be dried which is arranged on the rotating plate 61 and is rotationally conveyed. Since the flow rate of the drying gas ejected from each of the drying gas ejection nozzles 74 is substantially uniform, the material to be dried W can be heated uniformly.

Here, the drying gas ejected from each of the drying gas ejection nozzles 74 spreads in the annular drying space 53. As a result, the temperature of the drying space 53 can be made uniform.

Since the drying gas in the combustion chamber 20 is sucked by the circulation fan 110, the pressure in the combustion chamber 20 becomes lower than the pressure in the drying space 53 of the drying chamber 50. Therefore, the drying gas in the drying space 53 is guided to the combustion chamber 20 through the return pipe 101.

At this time, air is also sucked from the end of the branch pipe 106 on the atmosphere open side. Then, a predetermined amount of air is introduced into the return pipe 101 via the branch pipe 106 and is introduced into the combustion chamber 20.

The drying gas and the air introduced into the combustion chamber 20 through the return pipe 101 are mixed with the combustion gas generated by the combustion in the burner 30, are sucked into the introduction pipe 100, and enter the gas ejection portion 70 of the drying chamber 50. be introduced.

Thus, a part of the drying gas generated in the combustion chamber 20 is circulated to the combustion chamber 20 via the drying chamber 50.

Here, the flow rate of the air introduced through the branch pipe 106 is the same as the flow rate of the combustion gas discharged into the atmosphere through the branch pipe 103.

Introducing the atmosphere from the branch pipe 106 and discharging a part of the drying gas from the branch pipe 103 in this manner suppresses an increase in the concentration of volatile organic compounds (VOC) in the circulation system of the drying gas. This is because. This can prevent accidents such as explosions. The volatile organic compound is contained in, for example, paint.

Here, a part of the drying gas in the drying space 53 is sucked from one end of the return pipe 101 connected to the casing 51. For example, even when the slide door 55 is open, by providing the return pipe 101 so that the virtual straight line P1 is located in the range of the angle d1 from the virtual straight line L in the direction opposite to the transport rotation, the return pipe 101 is sucked to the outside. The inflow of air into the drying space 53 is suppressed.

On the other hand, the drying gas flowing through the branch pipe 105 branched from the introduction pipe 100 is guided to the hot air jet pipe 102. The drying gas guided to the hot air jet pipe 102 is jetted from the casing 51 side toward the outer cylinder 71 side. The drying gas jetted from the hot air jet pipe 102 is jetted in the direction along the virtual straight line Q1, for example.

The drying gas jetted from the hot air jet pipe 102 forms a flow of the drying gas in the direction along the virtual straight line Q1, for example. Due to the flow along the virtual straight line Q1, for example, even when the outside air flows into the drying space 53 from the carry-in/carry-out port 54 in the state where the slide door 55 is opened, the transport rotation is higher than the flow along the virtual straight line Q1. It is possible to prevent air from flowing in the opposite direction. That is, the drying gas ejected from the hot air ejection pipe 102 has an external air diffusion preventing function of preventing the external air flowing from the carry-in/carry-in port 54 from spreading to the drying space 53.

Here, the flow rate ratio (S:T1) of the flow rate S of the drying gas ejected from the drying gas ejection nozzle 74 to the drying space 53 and the flow rate T1 of the drying gas ejected from the hot air ejection tube 102 to the drying space 53. ) Is preferably 85:5 to 45:45. The flow rate S is the total flow rate of the drying gas ejected from each of the drying gas ejection nozzles 74.

The flow rate S is set to be greater than or equal to the flow rate T1. Then, when the value of the flow rate ratio S:T1 and the value of T1 are added to be 90, the ratio of T1 increases as the ratio of S decreases from 85. For example, if the S ratio decreases from 85 to 60, the T1 ratio increases from 5 to 30.

By setting the flow rate S and the flow rate T1 within the range of the above flow rate ratio, the temperature of the drying space 53 can be maintained at an appropriate temperature and the drying space 53 can be maintained in a uniform temperature state with a small temperature distribution. The flow rate ratio S:T1 is more preferably 85:5 to 70:20.

As described above, according to the drying device 10 of the first embodiment, the slide door 55 is provided by providing the hot-air jetting pipe 102 and providing the return pipe 101 and the hot-air jetting pipe 102 at the positions within the predetermined range of the casing 51. Even when is open, the outside air can be suppressed from flowing into the drying space 53 through the carry-in/carry-in port 54. As a result, the temperature of the drying space 53 can be maintained at an appropriate temperature and the drying space 53 can be maintained in a uniform temperature state with a small temperature distribution.

Further, by providing the return pipe 101 and the hot air blowing pipe 102 at positions in a predetermined range of the casing 51, even when external air flows into the drying space 53 from the carry-in/carry-in port 54 in the state where the slide door 55 is open. The influence of the air on the temperature distribution is small, and the temperature of the drying space 53 can be maintained at an appropriate temperature and uniformly.

Further, by providing the drying gas ejection nozzle 74 at a position within a predetermined range of the outer cylinder 71, the drying gas ejection nozzle 74 arranged on the most upstream side in the transport rotation direction when the slide door 55 is in the open state. It is possible to prevent the drying gas ejected from the tank from directly flowing out through the carry-in/carry-in port 54. As a result, the energy of the drying gas can be effectively used for drying the material W to be dried. It also contributes to maintaining the temperature of the drying space 53 at an appropriate temperature.

(Second embodiment)
FIG. 3 is a diagram schematically showing an outline of the drying device 11 according to the second embodiment. The same components as those of the drying device 10 according to the first embodiment are designated by the same reference numerals, and overlapping description will be omitted or simplified.

The drying device 11 according to the second embodiment is provided with a hot air jet pipe 120 having another function, instead of the hot air jet pipe 102 having the external air diffusion preventing function in the first embodiment. Further, in the drying device 11 of the second embodiment, the connecting position of the return pipe 101 with the casing 51 is also different from the connecting position of the return pipe 101 with the casing 51 in the first embodiment.

Here, the configuration of the hot air jet pipe 120 having other functions and the connection position of the return pipe 101 with the casing 51 will be mainly described.

The sectional structure shown in FIG. 2 in the first embodiment is the same as the sectional structure of the drying device 11 in the second embodiment corresponding to this section.

As shown in FIG. 3, the drying chamber 50 is connected to the introduction pipe 100, the return pipe 101, and the hot air jet pipe 120.

First, the connection position of the return pipe 101 with the casing 51 will be described.

The return pipe 101 communicates the drying space 53 of the drying chamber 50 with the combustion chamber 20. As shown in FIG. 3, one end of the return pipe 101 is connected to the casing 51 so as to communicate with the drying space 53 of the drying chamber 50. The return pipe 101 is formed, for example, in the axial center of the casing 51 in the drying chamber 50. The return pipe 101 is provided in each drying chamber 50.

Here, as shown in FIG. 3, a virtual straight line connecting the center of the return pipe 101 in the circumferential direction at the connection position with the casing 51 and the transport rotation axis center O is P2. The angle between the virtual straight line L and the virtual straight line P2 in the reverse transport rotation direction (counterclockwise direction in FIG. 3) is d2.

The angle d2 formed by the virtual straight line L and the virtual straight line P2 is preferably 45 degrees or more and less than 225 degrees, or 315 degrees or more and less than 360 degrees. That is, the center in the circumferential direction of the return pipe 101 at the connection position with the casing 51 is within the range of 45 degrees or more and less than 225 degrees in the direction opposite to the transport rotation direction from the center of the circumferential direction of the carry-in/carry-in port 54, or 315. It is located within the range of more than 360 degrees and less than 360 degrees.

When the angle d2 is close to 360 degrees, the connection position of the return pipe 101 with the casing 51 is set in view of the relationship with the position of the carry-in/carry-in port 54, and in terms of production and function. That is, when the angle d2 is close to 360 degrees, the return pipe 101 is connected to a position as close as possible to the carry-in/carry-out port 54 within a range that does not impair the function of the carry-in/carry-out port 54 and a range that is structurally possible.

By setting the angle d2 within the above range, the temperature of the drying space 53 can be maintained at an appropriate temperature and even when the sliding door 55 is open. Even when the slide door 55 is open, it is possible to prevent external air from flowing into the drying space 53 from the carry-in/carry-in port 54 due to suction in the return pipe 101, for example. Further, even when the outside air flows into the drying space 53 through the carry-in/carry-in port 54 in the state where the slide door 55 is open, the influence of the air on the temperature distribution is small, and the temperature of the drying space 53 is set to an appropriate temperature. And can be maintained uniform.

Here, the angle d2 is more preferably 45 degrees or more and 135 degrees or less. Further, the angle d2 is more preferably 45 degrees or more and 90 degrees or less. In these cases, the flow rate of the external air drawn into the drying space 53 from the carry-in/carry-in port 54 by suction of the return pipe 101 can be further suppressed.

In addition, as described above, when the air flowing into the drying space 53 from the carry-in/carry-out port 54 is directly sucked into the return pipe 101 along the inner peripheral surface of the casing 51 and guided to the combustion chamber 20, the inside of the combustion chamber 20 is dried. The temperature of the working gas drops. In this case, the output of the burner 30 is increased in order to keep the temperature of the drying gas in the combustion chamber 20 constant. Therefore, the fuel consumption increases.

However, when the angle d2 is in the range of 45 degrees or more and 135 degrees or less, it is possible to suppress that the air flowing into the drying space 53 from the carry-in/carry-in port 54 is directly sucked into the return pipe 101 along the inner peripheral surface of the casing 51. Therefore, it is possible to prevent the temperature of the drying gas in the combustion chamber 20 from decreasing due to the drying gas returned to the combustion chamber 20. This suppresses an increase in fuel consumption in the burner 30.

The shape of the return pipe 101 is as described above.

Next, the connection position of the hot air jet pipe 120 with the casing 51 will be described.

As shown in FIG. 3, a hot air jet pipe 120 is connected to the casing 51 of the drying chamber 50 in the drying device 11. The hot air jet tube 120 is formed, for example, in the axial center of the casing 51 in the drying chamber 50. The hot air jet pipes 120 are provided in the respective drying chambers 50.

The hot-air ejection pipe 120 ejects the drying gas from the casing 51 side to the drying space 53. A branch pipe 130 branched from the introduction pipe 100 is connected to the hot air jet pipe 120. The branch pipe 130 is provided with a flow rate adjusting unit 131 for adjusting the flow rate of the drying gas ejected into the drying space 53.

Although the branch pipe 130 is branched on the circulation fan 110 side with respect to the branch pipe 103, it may be branched on the downstream side (gas ejection portion 70 side) with respect to the branch point where the branch pipe 103 is branched.

The number of hot air jetting pipes 120 connected to the casing 51 may be one or two or more. When two or more hot air jet pipes 120 are provided, the hot air jet pipes 120 are, for example, arranged at equal intervals in the axial direction.

When two or more hot air jet pipes 120 are provided, for example, the downstream end of the branch pipe 130 branches corresponding to each hot air jet pipe 120, and this branch pipe is connected to each hot air jet pipe 120, respectively. When two or more hot air jet pipes 120 are provided, a buffer portion forming a buffer space may be provided at the downstream end of the branch pipe 130, and the upstream end portion of each hot air jet pipe 120 may be connected to this buffer portion.

The drying gas ejected from the hot air ejection pipe 120 here has a function of making the temperature distribution of the drying gas in the drying space 53 uniform, which will be described in detail later.

Here, the hot-air jetting pipe 120 is connected to the casing 51 provided in the circumferential direction in a range facing the drying gas jetting nozzle 74. An imaginary straight line connecting the center of the hot air jet tube 120 in the circumferential direction at the connecting position with the casing 51 and the center O of the transport rotation axis is denoted by Q2. In this case, the virtual straight line Q2 is located in the range from the virtual straight line M to the virtual straight line N in the transport rotation direction.

The virtual straight line M and the virtual straight line N are as described in the first embodiment.

The circumferential center of the hot-air jetting pipe 120 at the connection position with the casing 51 is opposed to the central axis of the drying gas jetting nozzle 74 located in the center of the drying gas jetting nozzles 74 arranged in the circumferential direction, for example. It is more preferable to be located within a range of 45 degrees in the transport rotation direction and 45 degrees in the transport rotation reverse direction from the position.

Further, the connection position of the hot air jetting pipe 120 with the casing 51 is set so as not to overlap with the connection position of the return pipe 101 with the casing 51.

By arranging the hot air jet pipe 120 in the above range, the temperature in the heating zone in the drying space 53 where the drying target gas W is heated by spraying the drying gas can be maintained at an appropriate and uniform temperature. Furthermore, it is possible to make the temperature uniform while maintaining the temperature of the drying space 53 other than the heating zone at an appropriate temperature.

Here, with respect to the temperature in the heating zone and the drying space 53 other than the heating zone described above, the difference from the temperature of the drying gas jetted from the drying gas jet nozzle 74 is maintained within a range of 15° C., for example. It is preferable.

It should be noted that the hot-air jet pipe 120 is composed of, for example, a tubular pipe or the like, similarly to the hot-air jet pipe 102 of the first embodiment. As the tubular tube, for example, a tube having a rectangular sectional shape perpendicular to the central axis of the tubular tube, or a tube having a circular sectional shape perpendicular to the central axis of the tubular tube is used.

Next, the operation of the drying device 11 will be described. The description of the same operation as that of the drying device 10 will be omitted or simplified.

At the start of operation of the drying device 10, the intake fan 32a and the circulation fan 110 are driven. As described above, the drying gas flowing through the introduction pipe 100 into the individual space 78 from the second space 76 is jetted from the drying gas jet nozzle 74 to the drying space 53.

The drying gas ejected into the drying space 53 collides with the article W to be dried which is arranged on the rotating plate 61 and is rotationally conveyed. Since the flow rate of the drying gas ejected from each of the drying gas ejection nozzles 74 is substantially uniform, the material to be dried W can be heated uniformly.

Here, the drying gas ejected from each of the drying gas ejection nozzles 74 spreads in the annular drying space 53.

Since the drying gas in the combustion chamber 20 is sucked by the circulation fan 110, the drying gas in the drying space 53 is guided to the combustion chamber 20 through the return pipe 101. At this time, air is also sucked from the end of the branch pipe 106 on the atmosphere open side.

The drying gas and the air introduced into the combustion chamber 20 through the return pipe 101 are mixed with the combustion gas generated by the combustion in the burner 30, are sucked into the introduction pipe 100, and enter the gas ejection portion 70 of the drying chamber 50. be introduced.

Thus, a part of the drying gas generated in the combustion chamber 20 is circulated to the combustion chamber 20 via the drying chamber 50.

Here, a part of the drying gas in the drying space 53 is sucked from one end of the return pipe 101 connected to the casing 51. For example, even when the slide door 55 is open, by providing the return pipe 101 so that the virtual straight line P2 is positioned in the range of the angle d2 from the virtual straight line L in the direction opposite to the conveyance rotation, the return pipe 101 is sucked to the outside The inflow of air into the drying space 53 is suppressed.

On the other hand, the drying gas flowing through the branch pipe 130 branched from the introduction pipe 100 is guided to the hot air blowing pipe 120. The drying gas guided to the hot air jet pipe 120 is jetted from the casing 51 side toward the outer cylinder 71 side. The drying gas ejected from the hot air ejection pipe 120 is ejected in the direction along the virtual straight line Q2, for example.

Here, in the drying space 53, the drying gas jetted from the hot air jetting pipe 120 and the drying gas jetted from the drying gas jetting nozzle 74 facing the hot air jetting pipe 120 form an opposing jet flow. The jets from both of the conveyed articles W to be dried directly collide with each other. When the article to be dried W intervenes, jets from both sides collide with each other via the article to be dried W.

The area in the drying space 53 where the drying gas is blown to heat the article to be dried W is the heating zone described above.

As the jet flows collide with each other in this manner, the flow field of the drying gas in the drying space 53 is disturbed. Thereby, the temperature distribution in the drying space 53 is made uniform.

In the area provided with the drying gas ejection nozzle 74 and providing a sufficient amount of heat to the material to be dried W, the temperature distribution in the drying space 53 is made uniform as described above. Therefore, the material to be dried W can be appropriately dried. Further, by jetting the drying gas from the hot air jet pipe 120, the temperature distribution in the entire drying space 53 can be made uniform.

In this way, the drying gas jetted from the hot air jet pipe 120 has a function of making the temperature distribution in the drying space 53 uniform.

Here, a flow rate ratio (S:T2) of the flow rate S of the drying gas jetted from the drying gas jet nozzle 74 to the drying space 53 and the flow rate T2 of the drying gas jetted from the hot air jet tube 120 to the drying space 53. ) Is preferably 85:5 to 45:45. The flow rate S is the total flow rate of the drying gas ejected from each of the drying gas ejection nozzles 74.

The flow rate S is set to be greater than or equal to the flow rate T2. Then, when the value of the flow rate ratio S:T2 and the value of T2 are added to be 90, the ratio of S2 is increased by an amount corresponding to the decrease of the ratio of S from 85. For example, if the S ratio decreases from 85 to 60, the T2 ratio increases from 5 to 30.

By setting the flow rate S and the flow rate T2 within the range of the above flow rate ratio, the temperature of the drying space 53 can be maintained at an appropriate temperature and the drying space 53 can be maintained in a uniform temperature state with a small temperature distribution. The flow rate ratio S:T2 is more preferably 85:5 to 70:20.

As described above, according to the drying device 11 of the second embodiment, by providing the return pipe 101 at a position within a predetermined range of the casing 51, even if the slide door 55 is open, the return pipe 101 can be removed from the carry-in/carry-out port 54. It is possible to suppress the outside air from flowing into the drying space 53.

Further, by providing the hot-air jetting pipe 120 and providing the return pipe 101 and the hot-air jetting pipe 120 at positions within a predetermined range of the casing 51, the temperature distribution in the drying space 53 can be made uniform even when the slide door 55 is open. Can be planned.

As a result, the temperature of the drying space 53 can be maintained at an appropriate temperature and the drying space 53 can be maintained in a uniform temperature state with a small temperature distribution.

Further, by providing the drying gas ejection nozzle 74 at a position within a predetermined range of the outer cylinder 71, the drying gas ejection nozzle 74 arranged on the most upstream side in the transport rotation direction when the slide door 55 is in the open state. It is possible to prevent the drying gas ejected from the tank from directly flowing out through the carry-in/carry-in port 54. As a result, the energy of the drying gas can be effectively used for drying the material W to be dried. It also contributes to maintaining the temperature of the drying space 53 at an appropriate temperature.

In addition, in the above-mentioned embodiment, an example in which the combustion gas generated in the burner 30 is used as the drying gas is shown, but the drying gas may be generated by other means. For example, air heated in an electric furnace or the like may be used as the drying gas.

(Evaluation of temperature distribution of drying gas in the drying space 53)
Next, the temperature distribution of the drying gas in the drying space 53 is evaluated. Here, a drying chamber 50 having a hot air jet pipe 102 having a function of preventing the external air flowing from the carry-in/carry-out port 54 from spreading to the drying space 53 (external air diffusion preventing function), and the temperature distribution in the drying space 53. The temperature distribution of the drying gas in the drying space 53 is evaluated for the drying chamber 50 including the hot-air jetting pipe 120 having the function of making the temperature uniform (temperature distribution uniformizing function).

The temperature distribution was calculated by numerical analysis. Further, in the numerical analysis, the temperature distribution of the drying gas in the drying space 53 in the state where the slide door 55 is opened, that is, the loading/unloading port 54 is opened to the outside is analyzed.

An analysis model of the drying chamber 50 including the hot air jet pipe 102 (analysis model A) and an analysis model of the drying chamber 50 including the hot air jet pipe 120 (analysis model B) will be described.

(Analysis model A)
FIG. 4 is a diagram schematically showing the configuration of the analysis model A in a simplified manner. FIG. 5 is a plan view of the drying gas ejection nozzle 74 provided in the outer cylinder 71 when viewed from the front.

In the analysis model A shown in FIG. 4, the inner diameter of the casing 51 is 3000 mm and the outer diameter of the outer cylinder 71 is 1200 mm. The height (height in the axial direction) of the drying space 53 in the drying chamber 50 is 500 mm.

The opening width in the circumferential direction of the carry-in/carry-in port 54 is 700 mm, and the opening height of the carry-in/carry-in port 54 (axial opening height) is 400 mm. The carry-in/carry-in port 54 is formed at the center of the casing 51 in the drying chamber 50 in the height direction (axial direction).

The angle a formed by the virtual straight line L and the virtual straight line M is 36 degrees. An angle b formed by the virtual straight line M and the virtual straight line N is 180 degrees. Regarding the drying gas ejection nozzles 74, as shown in FIG. 5, a row having five drying gas ejection nozzles 74 at equal intervals in the axial direction (vertical direction) and four drying gas ejection nozzles in the axial direction are provided. Rows provided with the gas ejection nozzles 74 are provided alternately in the circumferential direction. The pitch U between the rows in the circumferential direction is equal.

In the row including the four drying gas ejection nozzles 74, each of the drying gas ejection nozzles 74 has the drying gas ejection nozzles 74 in the row including the five drying gas ejection nozzles 74 when viewed in the circumferential direction. It is located in between. That is, the array of the drying gas ejection nozzles 74 is a staggered array in the circumferential direction.

The drying gas ejection nozzle 74 is a circular tube having an inner diameter of 27.8 mm, and projects 100 mm from the outer peripheral surface 71 a of the outer cylinder 71. On the outer peripheral surface 71a of the outer cylinder 71, 115 drying gas ejection nozzles 74 are arranged.

An angle e1 formed by the virtual straight line L and the virtual straight line Q1 is 40 degrees. The hot-air jet pipe 102 is a pipe having a square cross section perpendicular to the central axis, and the inner dimensions at the outlet of the hot-air jet pipe 102 are a square with a width of 200 mm and a height of 200 mm.

The return pipe 101 is a pipe having a rectangular cross-sectional shape perpendicular to the central axis, and the inner dimension at the outlet of the return pipe 101 is a rectangle having a width of 600 mm and a height of 300 mm.

The height of the hot air jetting pipe 102 and the return pipe 101 is the length in the vertical direction. The hot air jetting pipe 102 and the return pipe 101 are connected to the center of the casing 51 in the drying chamber 50 in the axial direction (vertical direction).

Here, the temperature distribution was evaluated by changing the connection position of the return pipe 101 with the casing 51 in the circumferential direction. The angle d1 formed by the virtual straight line L and the virtual straight line P1 was changed to 90 degrees, 135 degrees, 180 degrees, 225 degrees, 270 degrees, and 315 degrees, and the temperature distribution was evaluated for each.

Here, the flow rate ratio (S:T1) of the flow rate S of the drying gas ejected from the drying gas ejection nozzle 74 to the drying space 53 and the flow rate T1 of the drying gas ejected from the hot air ejection tube 102 to the drying space 53. ) Was set to 85:5. The total flow rate, which is the sum of the flow rate S and the flow rate T1, is set to 90 m ³ /min. The temperature of the drying gas jetted from the drying gas jet nozzle 74 and the hot air jet pipe 102 into the drying space 53 was 170°C.

The temperature distribution of the drying gas in the drying space 53 was evaluated based on the temperatures at the evaluation positions F1 to F16 shown in FIG. Here, the evaluation positions F1 to F16 are located at equal intervals on a circle having a diameter of 2100 mm with the transport rotation axis center O as the center. In other words, the evaluation positions F1 to F16 are located at equal intervals on the circumference that is the center between the inner peripheral surface of the casing 51 and the outer peripheral surface 71a of the outer cylinder 71.

The height (height in the axial direction) of the evaluation positions F1 to F16 in the dry space 53 is 250 mm. That is, the evaluation positions F1 to F16 are located at the center of the height (axial height) of the drying space 53 in the drying chamber 50.

Here, the evaluation position F1 is located on the virtual straight line L in the cross section shown in FIG. The evaluation position F2 and the evaluation position F3 are sequentially set from the evaluation position F1 to the evaluation position F16 in the transport rotation direction.

FIG. 6 is a diagram showing the evaluation result of the temperature distribution of the drying gas in the drying space 53 in the analysis model A. In FIG. 6, the abscissa indicates the evaluation position, and the ordinate indicates the temperature of the drying gas.

As shown in FIG. 6, when the angle d1 is 90 degrees, 135 degrees, 180 degrees, 225 degrees, and 315 degrees, the temperature in the area (F3 to F10) in the drying space 53 provided with the drying gas ejection nozzle 74 is high. A uniform temperature condition with a small distribution is obtained. The region of F3 to F10 corresponds to the heating zone described above.

When the angle d1 is 315 degrees, a small amount of air flowing into the drying space 53 from the carry-in/carry-in port 54 is directly sucked into the return pipe 101 along the inner peripheral surface of the casing 51, but a uniform temperature distribution is obtained. ing.

Further, when the angle d1 is 90 degrees and 135 degrees, a uniform temperature state with a small temperature distribution is obtained in the regions F11 to F15 other than the region where the drying gas ejection nozzle 74 is provided.

Although not shown here, even when the flow rate ratio (S:T1) is 45:45, the same result as that when the flow rate ratio (S:T1) is 85:5 is obtained. Was given.

(Analysis model B)
FIG. 7 is a diagram schematically showing the configuration of the analysis model B in a simplified manner. In the analysis model B, the inner diameter of the casing 51 and the outer diameter of the outer cylinder 71 are the same as those of the analysis model A. The size and position of the carry-in/carry-in port 54 are the same as those of the analysis model A.

The angle a formed by the virtual straight line L and the virtual straight line M, the angle b formed by the virtual straight line M and the virtual straight line N, and the shape and arrangement of the drying gas ejection nozzle 74 are the same as those of the analysis model A.

The virtual straight line Q2 is provided at a position that is advanced by 180 degrees in the transport rotation direction from the virtual straight line L. That is, the center in the circumferential direction of the hot-air jetting pipe 120 at the connection position with the casing 51 is provided at a position that is advanced by 180 degrees in the transport rotation direction from the center in the circumferential direction of the carry-in/carry-out port 54.

The shape of the return pipe 101 is the same as the shape of the return pipe 101 of the analysis model A. Further, the shape of the hot air jet pipe 120 is the same as the shape of the hot air jet pipe 102 of the analysis model A.

The connecting positions of the return pipe 101 and the hot air jet pipe 120 in the height direction (axial direction) of the casing 51 are the same as those of the return pipe 101 and the hot air jet pipe 102 of the analytical model A, respectively.

Here, the temperature distribution was evaluated by changing the connection position of the return pipe 101 with the casing 51 in the circumferential direction. The angle d2 formed by the virtual straight line L and the virtual straight line P2 was changed to 45 degrees, 90 degrees, 135 degrees, 225 degrees, 270 degrees, and 315 degrees, and the temperature distribution was evaluated for each.

Here, a flow rate ratio (S:T2) of the flow rate S of the drying gas jetted from the drying gas jet nozzle 74 to the drying space 53 and the flow rate T2 of the drying gas jetted from the hot air jet tube 120 to the drying space 53. ) Was set to 85:5. The total flow rate, which is the sum of the flow rate S and the flow rate T2, is set to 90 m ³ /min. The temperature of the drying gas jetted from the drying gas jet nozzle 74 and the hot air jet pipe 120 into the drying space 53 was 170°C.

The evaluation positions F1 to F16 shown in FIG. 7 are the same as the evaluation positions F1 to F16 shown in FIG.

FIG. 8 is a diagram showing the evaluation result of the temperature distribution of the drying gas in the drying space 53 in the analysis model B. In FIG. 8, the horizontal axis indicates the evaluation position, and the vertical axis indicates the temperature of the drying gas.

As shown in FIG. 8, when the angle d2 is 45 degrees, 90 degrees, 135 degrees, and 315 degrees, the temperature distribution is small in the area (F3 to F10) in the drying space 53 provided with the drying gas ejection nozzle 74. A uniform temperature condition is obtained.

When the angle d2 is 315 degrees, a small amount of air flowing into the drying space 53 from the carry-in/carry-in port 54 is directly sucked into the return pipe 101 along the inner peripheral surface of the casing 51, but a uniform temperature distribution is obtained. ing.

Further, when the angle d2 is 45 degrees, 90 degrees, and 135 degrees, a uniform temperature state with a small temperature distribution is obtained in the regions F11 to F16 other than the region where the drying gas ejection nozzle 74 is provided. .. Among these, when the angle d2 is 45 degrees and 90 degrees, a more uniform temperature distribution is obtained.

Although not shown here, even when the flow rate ratio (S:T1) is 45:45, the same result as that when the flow rate ratio (S:T1) is 85:5 is obtained. Was given.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the scope equivalent thereto.

10, 11... Drying device, 20... Combustion chamber, 20a... One end, 20b... Other end, 21... Filter, 30... Burner, 31... Fuel supply system, 32... Air supply system, 32a... Intake fan, 50... Drying chamber , 51... Casing, 52... Lid member, 53... Drying space, 54... Carrying-in/carrying-in port, 55... Slide door, 60... Conveying device, 61... Rotating plate, 70... Gas ejection part, 71... Outer cylinder, 71a... Outer periphery Surface, 72... Inner cylinder, 72a... Outer peripheral surface, 73... Partition plate, 74... Drying gas ejection nozzle, 75... First space, 76... Second space, 77... Opening, 78... Individual space, 80... Opening degree adjusting section, 81... Sliding member, 82... Supporting member, 100... Introducing pipe, 101... Return pipe, 102, 120... Hot air blowing pipe, 103, 105, 106, 130... Branch pipe, 104, 107, 108, 131... Flow rate adjusting part, 110... Circulation fan, 111... Fan motor, W... Dried object.

Claims (3)

A drying device for drying an object to be dried by jetting a drying gas generated by a drying gas generating device toward an object to be dried that is rotatably conveyed,
A tubular casing,
A cylinder provided in the casing, into which the drying gas generated by the drying gas generation device is introduced,
Between the casing and the tubular body, the central axis of the tubular body can be rotated about a transport rotation axis, and a plurality of stages are provided in the central axis direction of the tubular body, and the article to be dried is arranged on the upper part. An annular flat plate-shaped rotating plate,
A carrying-in/carrying-in port formed in the casing for carrying in and out the dried object;
The drying gas introduced into the cylinder is ejected toward an object to be dried which is provided on the outer periphery of the cylinder and is rotatably conveyed in a drying space surrounded by the casing, the cylinder and the rotary plate. A plurality of drying gas ejection nozzles,
A return pipe that is connected to the casing and guides a part of the drying gas in the drying space to the drying gas generation device;
A hot air jet pipe connected to the casing and jetting a part of the drying gas generated by the drying gas generation device into the drying space,
An imaginary straight line connecting the center of the transport rotation axis and the center of the carry-in/carry-out port in the circumferential direction is defined as L, and the upstream side end of the drying gas ejection nozzle arranged on the most upstream side in the transport rotation direction and the transport. When an imaginary straight line connecting the center of the rotation axis is M, an angle a between the imaginary straight line L and the imaginary straight line M in the transport rotation direction is 35 degrees or more and 90 degrees or less,
When a virtual straight line connecting the downstream side end of the drying gas ejection nozzle arranged on the most downstream side in the transport rotation direction and the transport rotation axis center is N, the virtual straight line M is moved in the transport rotation direction from the virtual straight line M. The angle b formed by the virtual straight line N is 135 degrees or more and 270 degrees or less,
When an imaginary straight line connecting the center of the return pipe in the circumferential direction at the connection position with the casing and the center of the transport rotation axis is P1, the imaginary straight line L extends in the reverse direction of the transport rotation from the imaginary straight line P1. The angle d1 is 45 degrees or more and 225 degrees or less, or 315 degrees or more and less than 360 degrees,
When an imaginary straight line connecting the circumferential center of the hot air blast pipe at the connection position with the casing and the transport rotation axis center is Q1, the imaginary straight line L extends from the imaginary straight line L to the imaginary straight line Q1 in the reverse transporting direction. The drying apparatus is characterized in that an angle e1 formed is greater than 0 degree and 50 degrees or less. A drying device for drying an object to be dried by jetting a drying gas generated by a drying gas generating device toward an object to be dried that is rotatably conveyed,
A tubular casing,
A cylinder provided in the casing, into which the drying gas generated by the drying gas generation device is introduced,
It is rotatable between the casing and the tubular body with the central axis of the tubular body as the center of rotation axis for conveyance, and is provided in a plurality of stages in the central axial direction of the tubular body, and the article to be dried is arranged on the upper part. An annular flat plate-shaped rotating plate,
A carrying-in/carrying-in port formed in the casing for carrying in and out the dried object;
The drying gas introduced into the cylinder is ejected toward an object to be dried which is provided on the outer periphery of the cylinder and is rotatably conveyed in a drying space surrounded by the casing, the cylinder and the rotary plate. A plurality of drying gas ejection nozzles,
A return pipe that is connected to the casing and guides a part of the drying gas in the drying space to the drying gas generation device;
A hot air jet pipe connected to the casing and jetting a part of the drying gas generated by the drying gas generation device into the drying space,
An imaginary straight line connecting the center of the transport rotation axis and the center of the carry-in/carry-out port in the circumferential direction is defined as L, and the upstream side end of the drying gas ejection nozzle arranged on the most upstream side in the transport rotation direction and the transport. When an imaginary straight line connecting the center of the rotation axis is M, an angle a between the imaginary straight line L and the imaginary straight line M in the transport rotation direction is 35 degrees or more and 90 degrees or less,
When a virtual straight line connecting the downstream side end of the drying gas ejection nozzle arranged on the most downstream side in the transport rotation direction and the transport rotation axis center is N, the virtual straight line M is moved in the transport rotation direction from the virtual straight line M. The angle b formed by the virtual straight line N is 135 degrees or more and 270 degrees or less,
When a virtual straight line connecting the center of the return pipe in the circumferential direction at the connection position with the casing to the center of the transport rotation axis is P2, the virtual straight line L extends in the reverse transport rotation direction to the virtual straight line P2. The angle d2 is 45 degrees or more and less than 225 degrees, or 315 degrees or more and less than 360 degrees,
The drying device is characterized in that the hot air jetting pipe is provided in a range facing the drying gas jetting nozzle in the casing. The flow rate ratio (S:T) of the flow rate S of the drying gas ejected from the drying gas ejection nozzle to the drying space and the flow rate T of the drying gas ejected from the hot air ejection tube to the drying space is 85:5. The drying device according to claim 1 or 2, wherein the drying device is about 45:45.

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