JP6993728B2 - Hot air drying furnace - Google Patents

Description

The present invention relates to a hot air drying furnace in which a work to be heated housed in the furnace is dried by hot air introduced from a hot air generator.

A hot air drying oven that introduces hot air from a hot air generator into the heating area and dries the work to be heated by the synergistic effect of heat and air is recognized as having a high drying effect, but simply heats the hot air inside the furnace. If the used air is blown onto the work and the used air is discharged from the exhaust port, the temperature distribution in the furnace will vary greatly due to the specification of the hot air flow in the furnace and the influence of the work, resulting in uniform results. Since drying is not possible, many drying furnaces have been proposed in which this variation is suppressed and the environment inside the furnace is made uniform.

For example, a box configured to provide a hot air outlet and a hot air suction port in the furnace body containing the work to be heated, blow out the hot air generated by the hot air generator into the furnace, and return the used hot air to the hot air generator. In a type of drying furnace, a shielding plate is installed at a position along the side surface of the material to be dried in the furnace, and a fan inside the furnace is provided in the space opposite to the side of the material to be dried with the shielding plate in between. From the drying furnace of Patent Document 1 in which the air velocity of hot air is made uniform in any part of the material to be dried, regardless of the distance from the hot air outlet by the fan in the furnace and the shielding plate, or from the lower part of the drying chamber. As a dryer that aims to stabilize the drying quality by standardizing the variation in the discharge amount distribution of hot air blown up and discharged into the drying chamber, a hot air volume adjustment plate is installed in the hot air passage at the bottom of the drying chamber, and a furnace is also provided. 2. Such dryers have been proposed.

In addition, instead of a box-type closed hot air drying furnace, hot air is used in a conveyor furnace that dries while moving the work. For example, infrared sources are placed vertically separated from the conveyor running path in the furnace. A conveyor furnace as in Patent Document 3, which attempts to control the temperature by forcibly stirring the hot air in the furnace with a fan at the same time as blowing the hot air from the hot air generator toward the conveyor in the furnace, has been proposed. There is.

Japanese Unexamined Patent Publication No. 6-34268 Japanese Unexamined Patent Publication No. 2010-244696 Japanese Unexamined Patent Publication No. 2000-160260

The challenge for these furnaces is how to supply uniform hot air to the work to be heated in the heating area (for example, inside the furnace) and keep the temperature inside the furnace stable. Trying to make the air velocity of hot air uniform, trying to distribute and adjust the amount of hot air blown up and discharged by an adjustment plate or rectifying plate, or forcibly stirring using a stirring fan in parallel with the use of an infrared source, etc. However, in the furnace, the environment such as the air flow changes due to the presence of the work itself, and in the conventional form in which hot air is blown directly onto the work, the hot air supplied to the work is discharged. No matter how much adjustment is made in stages, there is a limit to making this uniform.

In addition, since a hot air drying furnace naturally blows hot air onto the work to be heated to dry it, the work may be a lightweight work such as powder that is blown by the wind, or it may be deformed by wind pressure. What was not the target work of the hot air drying oven.

Therefore, the present invention adjusts the flow of hot air introduced from the hot air generator to equalize the atmospheric temperature of the heated compartment area in which the work to be heated is accommodated or installed, and as a result, the drying quality of the work is improved. That was the issue.

Another object of the present invention is to provide a hot air drying furnace that can be applied to a work to be heated such as powder that is affected by wind pressure even though it is a hot air drying furnace.

The hot air drying furnace of the present invention is a drying furnace in which hot air is introduced into a heated compartment to dry the work to be heated, and the hot air drying device arranged outside the compartment faces the hot air drying device in the compartment (inside the drying furnace) near the bottom surface . A hot air blowing part including a hot air discharge port, which is provided facing each other along the side surface and is arranged in a row from the front to the rear, and a hot air blowing part connected to both ends of the hot air blowing part from the hot air generator. The hot air supply passage for introducing the heated air and the center of the upper surface, which is the exhaust part of the air from the inside of the drying furnace to the outside, are provided in parallel with the hot air blowing part, and are arranged in a row from the front to the rear. A hot air return port including a hot air discharge port and an exhaust passage are provided, and the discharge port is provided with an upper surface facing upward along the side surface of the furnace when the hot air outlet is set in the drying furnace. , Provided on the side surface facing the opposite side surface along the bottom surface of the furnace, the discharge direction of the hot air blown from the discharge port of the hot air blowing portion does not directly face the work, and is parallel from the side surface of the wall surface in the drying furnace along the top surface and the bottom surface. Or, it is set slightly parallel to the wall surface.
Further, the hot air blowing portion may be provided facing each other along the facing side surfaces near the upper surface in addition to the vicinity of the bottom surface in the drying furnace, and the hot air return port may be provided in addition to the central portion of the upper surface in the drying furnace. It may be provided in the center of the bottom surface.
Further, the hot air drying furnace is preferably a conveyor furnace, and the hot air outlet provided near the bottom surface of the conveyor furnace is located below the conveyor belt, and the hot air outlet provided near the top surface is located above the conveyor belt. It is preferable to do so.

(Action)
According to this means, the hot air discharged from the hot air discharge port arranged from the front to the rear along the wall surface in the heating section area is along the inner wall surface of the drying furnace so as not to be directly blown to the work to be heated. By setting it parallel or slightly parallel to the wall surface, strong hot air does not blow to the work, and the strong flow of hot air in the drying furnace is the flow along the inner wall surface around the furnace. Become.

For example, a hot air blowing portion is provided facing the facing side surface near the bottom surface in the drying furnace from the front to the rear, and the discharge direction from the discharge port is set upward and on the bottom surface along the side surface in the drying furnace. If the hot air return port is set in a direction parallel to the surface along the surface and the hot air return port is provided in the center of the upper surface of the drying furnace in parallel with the hot air outlet, a large flow of hot air discharged from the hot air discharge port is provided. Ascends along both side surfaces in the drying furnace and becomes a flow toward the hot air return portion of the upper surface portion and a flow from both side surfaces of the bottom surface of the furnace toward the central portion along the bottom surface (see FIG. 7). It is possible to create a state in which the hot air does not directly hit the street work, and the hot air circulates around the work, as if the work is wrapped from the surroundings and heated in the heating section area.

Further, since the hot air supply passage for introducing the heated air from the hot air generator to the hot air blowing portion is arranged near both ends of the hot air blowing portion, the heated air is supplied from both sides of the hot air blowing portion and reaches the central portion. By colliding with each other, the flow of air in the hot air blowing portion can be complicated, and as a result, the air discharged from each discharge port can be made uniform.

The present invention is not based on the idea of blowing hot air directly onto the work to be heated in the conventional hot air drying furnace, but on the idea of equalizing the environment inside the drying furnace by using hot air. By discharging hot air along the inner wall surface, it is possible to heat the work to be heated from the surroundings while having a drying effect by the hot air.
Therefore, according to the hot air drying furnace of the present invention, by adjusting the flow of hot air introduced from the hot air generator as in the above-mentioned means, the atmospheric temperature of the heated compartment area in which the work to be heated is accommodated or installed is made uniform. As a result, the drying quality of the work can be improved.

In addition, even though it is a drying furnace that uses hot air, it can be applied to lightweight objects such as powder and those that change due to wind pressure as the target workpieces because strong hot air is not blown onto the workpiece to be heated. can.

The front view (the view seen from the door direction) of the whole structure which shows the box type hot air drying furnace in the 1st Embodiment of this invention. The side view of the said form. The block diagram which shows an example of the hot air generator of the said form. The block diagram which shows the hot air blowing tube of the said form. The block diagram which shows the hot air return pipe of the said form. The schematic diagram which shows the movement of the pipe and the air in the pipe of the said form. The schematic diagram which shows the main movement of the hot air in the furnace of the said form. The front view of the whole structure which shows the hot air drying furnace which made a hot air generator one unit in the modification of the said form. The front view (the view seen from the inlet direction side) which shows the structure of the conveyor furnace type hot air drying furnace in the 2nd Embodiment of this invention. In the side view of the said form, the schematic diagram which shows the flow of hot air outside the furnace, and the block diagram which shows the main body part of a drying furnace. The block diagram which shows the hot air blowing tube of the said form. The schematic diagram which shows the main movement of the hot air in the furnace of the said form.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 to 8 show a closed box type hot air drying furnace according to the first embodiment of the present invention, and FIG. 1 shows a front view schematically showing the overall configuration. FIG. 2 shows a side view thereof. For ease of understanding, FIG. 1 shows a door, and FIG. 2 shows an internal configuration in which the outer wall on the side surface is omitted.
The hot air drying furnace of this embodiment is a box-shaped drying furnace 2 used by mounting a work on a shelf 71 provided in a plurality of stages and mounting it on a trolley 7 in a drying chamber 22, and is provided outside the drying chamber. A plurality of hot air generators 1 (four units (1a to 1d) are used in this example) and a drying furnace main body 2 into which the hot air of the hot air generator 1 is introduced are provided, and the drying chamber 22 is near the bottom. A pair of left and right long hot air blowing pipes 3 provided in a length extending from the front to the rear of the room along the opposite side surfaces, and the central portion of the upper surface (ceiling surface) of the drying chamber 22. It is configured to include a long hot air return pipe 4 provided along the above-mentioned hot air blowout pipe 3 so as to be parallel to the hot air blowout pipe 3 and provided with a full length from the front to the rear of the room. The hot air drying device 1 and the hot air blowing pipe 3 are connected by a blowing passage 5, and the connecting portion 51 between the blowing passage 5 and the hot air blowing pipe 3 is set in the vicinity of both ends of the long hot air blowing pipe 3. .. On the other hand, the hot air return pipe 4 and the hot air generator 1 are connected by an exhaust passage 6, and the air exhausted from the drying chamber 22 is taken into the hot air generator 1 to circulate and heat the hot air. As for the temperature sensor, temperature setting, and control device that are naturally installed as a drying furnace, a known device may be provided at an appropriate position.

FIG. 3 shows an example of the hot air generator used in the above embodiment.
Since the hot air generator 1 may use a conventional hot air generator, detailed description of the configuration and structure is omitted, but the blower 12 is operated by operating the motor 11, and the air is generated by the rotation of the fan of the blower 12. Is forcibly taken into the blower 12 from the air suction port 15, heated while the taken-in air passes through the heater 13, and is forcibly discharged from the blower port 14 by the blower 12. Then, the hot air discharged from the air outlet 14 passes through the air passage 5 and is discharged from the hot air discharge port 32 of the hot air blowing pipe 3 to the drying chamber 22. Further, in this example, the heated air in the drying chamber 22 is partially recovered from the hot air return pipe 4 to the hot air generator 1 through the exhaust passage 6 so that the circulating hot air can be heated. There is. Even in this case, it is preferable that the air taken in from the suction port 15 of the hot air generator 1 is piped so that not only the exhaust air from the drying chamber 22 but also the fresh air can be taken in. In the hot air generator 1 of this example, the device is described as a device in which a blower port 14 is provided in the upper part of the front surface and a suction port 15 is provided in the lower part of the rear surface.

In the drying furnace of this embodiment, the four hot air generators (1a, 1b, 1c, 1d) of the same embodiment have front and rear surfaces (the front surface is provided with the air outlet 14 and the rear surface is) on the upper portion of the drying furnace main body 2. The surfaces provided with the suction ports 15) are used side by side so as to alternate, and the hot air generated from the air outlets 14 is formed in pairs through each of the connected air passages 5. The blowout pipe 3 is connected so as to be introduced one by one to the connection flanges 31 at four locations (two locations per one) near both ends. On the other hand, the end of the exhaust passage 6 is the hot air generator 1 so that the air exhausted from the drying chamber 22 is returned to each hot air drying device 1 through the four exhaust passages 6 connected to the hot air return pipe 5. It is connected to the intake port 15 via a filter (not shown). Further, in this example, the intake port 15 is formed in two forks, and one of the intake ports 15 is formed to be open to the outside as a fresh air intake port 16. In this embodiment, four hot air generators 1 are used, but if the capacity of hot air can be secured, two blower passages may be formed as two, and four hot air passages may be formed as one. It may also be formed. Further, in this embodiment, the four hot air generators are arranged alternately on the front and rear surfaces in order to efficiently set the pipes of the blower passage 5 and the exhaust passage 6 to be shorter by arranging the hot air blowout pipe 3 and the like, which will be described later. be. Further, the arrangement relationship between the drying furnace and the hot air generator may be set in any way.

The drying chamber 22 is assumed to be used by mounting a trolley 7 in which a work is loaded on a plurality of shelves 71 inside a drying furnace main body 2 formed in a box shape by an outer wall 21 and a front door 23. , It is formed as a rectangular parallelepiped space having a certain large volume (in this example, width, depth, height, about 2000 mm each).

FIG. 4 shows the hot air blowing tube of this embodiment.
The hot air blowout pipe 3 is formed as a hollow tubular body made of stainless steel or the like with both ends closed in the vicinity of the bottom of the drying chamber, set to a length substantially full of the chamber from the front to the rear along the opposite side surfaces. .. The shape etc. are not specified, but in this example, it was formed into a rectangular parallelepiped. Then, when it is installed at the bottom corner of the drying chamber 22, it serves as a hot air outlet to the drying chamber 22 arranged at appropriate intervals on the upper surface of the hot air blowing pipe 3 and the side surface facing the opposite surface. A plurality of holes were provided to form a hot air discharge port 32. By setting the discharge port 32 at the above position, the hot air introduced into the furnace is discharged upward along the side surface of the drying chamber 22 and in the direction parallel to the surface along the bottom surface. Become. (See Fig. 7)

Further, a port for taking in hot air from the hot air generator 1 to the hot air blowing pipe 3, that is, a connecting portion 51 with the blowing passage 5, is provided as flanges 31 near both ends of the hot air blowing pipe 3 as described above. Due to the nature of the fluid flow, the amount of air discharged from the hot air discharge port 32 changes depending on the distance from the flange 31, so the size of the hole is made larger toward the end, and the balance of discharge is taken into consideration. , It is preferable to set it. Further, the hot air blowing portion including the hot air discharging port 32 is not limited to the tubular body (hot air blowing pipe 3), and may be provided as a space like an elongated room on the side surface of the bottom of the drying chamber, for example. Further, the hot air discharge port 32 is not limited to the hole of this example, and may be an elongated slit or a device in which a plurality of nozzles are appropriately arranged.

FIG. 5 shows the hot air return pipe of this embodiment.
The hot air return pipe 4 is a hollow made of stainless steel or the like with both ends closed, which is set at the center of the upper surface (ceiling surface) of the drying chamber 22 in parallel with the hot air blowout pipe 3 from the front to the rear so as to be substantially the entire length of the room. It was formed as a tubular body, and although the shape is not specified, in this example, it was formed as a rectangular parallelepiped. Then, an appropriate interval is provided on the upper surface of the hot air return pipe 4, and flanges 41 connecting the other ends of the exhaust passage 6 to which the four hot air generators 1 are connected are provided at four places, and on both side surfaces. The air exhaust port 42 is provided with a plurality of holes serving as exhaust ports for used air from the drying chamber 22 arranged at appropriate intervals. At this time, it is preferable that the area of the entire air exhaust port is formed to be equal to or larger than the outlet 32 in consideration of an increase in air pressure in the drying chamber. Further, an exhaust port to the outside may be separately provided in the drying chamber 22 for pressure adjustment in the chamber or promotion of cooling after use.

The hot air return port is not limited to the tubular body, and may be, for example, a hole provided on the upper surface of the drying chamber 22 to be integrated with the exhaust passage 6, and the air exhaust port 42 may be a main body. The hole is not limited to the example hole, and an elongated slit or a plurality of nozzles may be appropriately arranged.

The arrangement of the hot air blowing portion / exhaust portion in the furnace, such as the hot air blowing pipe 3 and the hot air returning pipe 4, is not limited to this embodiment, and is not limited to this embodiment. The arrangement may be arranged so as to match the intention of heating so as to wrap the whole from the surroundings. For example, in the case of a large-width furnace, the hot air blowing tube 3 may be provided not only near the bottom surface but also near the top surface. It is also conceivable to provide the discharge port toward both side surfaces by providing it in the center of the bottom surface instead of the side surface near the bottom surface. Similarly, the setting position of the hot air return pipe 4 may be provided in the center of the bottom surface, and the arrangement, discharge direction, and the like may be set as necessary.

The blower passage 5 is a heat-resistant flexible hose that connects the hot air generator 1 and the hot air blowout pipe 3, and is provided near the flange of the blower port 14 of the hot air generator 1 and the vicinity of both ends of the hot air blowout pipe 3. It is formed by connecting both ends to the flange 31. Then, as described above, the hot air from the hot air generator 1 configured to be connected to each of the connecting portions 51 near both ends of the two hot air blowing pipes 3 facing each other of the four hot air generators 1 is blown into hot air. It is a passage to send to the blowout pipe 3. The ventilation passage 5 may be passed through the drying chamber 22 as in this example, or between the drying chamber 22 and the outer wall 21 of the furnace.

The exhaust passage 6 is a heat-resistant flexible hose that connects the hot air return pipe 4 and the hot air generator 1, and has both ends on the flange 41 provided on the upper surface of the hot air return pipe 4 and the flange of the intake port 15 of the hot air generator 1. Is a passage for returning the exhaust air from the drying chamber 22 to the hot air generator 1. The hot air return pipe 4 is provided with four flange 41 portions, each of which is formed by being connected to each of the four hot air generators 1a to 1d.

FIG. 6 shows a pipe connecting the hot air generator of the present embodiment and the drying chamber, and a schematic diagram showing the movement of air in the pipe.
To summarize the piping between the hot air generator 1 and the drying chamber 22 and the movement of the hot air, as described above, the hot air supply route from the hot air generator 1 to the hot air blowing pipe 3 and the drying chamber 22 through the air passage 5 and drying. There is a hot air return route from the room 22 to the hot air drying device 1 through the hot air return pipe 4 and the exhaust passage 6.

In this embodiment, four hot air generators 1 constituting the hot air supply route are arranged side by side in the width direction of the upper part of the drying furnace main body 2, while the hot air blowing pipe 3 is located at the bottom of the drying chamber 22. Flange 31s, which are set in the length direction on both side surfaces facing each other in the vicinity and serve as hot air intake ports thereof, are arranged near both ends. Therefore, the four parallel hot air generators are alternately set on the front and rear surfaces as an arrangement in which the blower passage 5 connecting the blower port 14 of the hot air generator 1 and the flange 31 of the hot air blowout pipe 3 is shortened and efficiently set. did. In this example, the blower passage 5 connected to the blower port 14 of the hot air generator 1a in which the blower port 14 located on the leftmost side when viewed from the front surface of the furnace is arranged on the front side is on the left side of the furnace. A hot air generator equipped with an air outlet 14 on the rear surface side at the second position from the left so as to be connected to the flange 31a on the front side of the arranged hot air blowing pipe 3 and similarly set the air passage 5 short. 1b is a flange 31b on the left rear side, a hot air generator 1c is the second from the right and has a blower port 14 on the front side. 1d is connected to the flange 31d on the right rear side.

On the other hand, a suction port 15 located on the rear surface opposite to the air outlet 14 of the hot air generator 1 and four flanges 41 serving as hot air discharge ports of the hot air return pipe 5 arranged in the longitudinal direction on the upper surface of the drying chamber 22. From the viewpoint of setting the exhaust passage 6 short and efficiently, the exhaust passage 6 connected to the suction port 15 of the hot air generator 1a is connected to the flange 41a on the innermost side of the hot air return pipe 4. Similarly, the hot air generator 1b is the second flange 41b from the front, the hot air generator 1c is the front flange 41c, and the hot air generator 1d is from the back so that the connection is such that the exhaust passage 6 is set short. It is connected to the second flange 41d. It should be noted that this arrangement shows the optimum arrangement from the relationship between the hot air generator of this embodiment and the furnace, and in other embodiments, of course, an arrangement suitable for that embodiment may be selected.

FIG. 7 shows a schematic diagram showing the main flow of hot air in the drying chamber of this embodiment.
In the hot air drying furnace of this embodiment, the hot air generated from the hot air generator 1 is introduced into the hot air blowing pipe 3 through the blowing passage 5, and is discharged from the hot air discharging port 32 into the drying chamber 22, but is introduced into the blowing pipe 3. The hot air is supplied from the vicinity of both ends (flange 31) of the blowout pipe 3, so that the hot air flows from both ends of the blowout pipe toward the central portion, collides with the central portion, and is inside the blowout pipe 3. The hot air discharged from each outlet 32 is introduced from, for example, from one direction due to the complicated flow of air and the change in the size of the hot air outlet 32 depending on the location. It can be expected to be uniform in comparison with.

Further, the hot air blowout pipe 3 is installed on both opposite side surfaces near the bottom of the drying chamber 22, the hot air return pipe 4 is installed in the center of the upper surface of the drying chamber 22, and the hot air discharge port 32 is the upper surface 32a of the blowout pipe. And because it is arranged on the opposite side surface 32b, the hot air introduced into the blowout pipe 3 is blown out in the upper F1 of the drying chamber 22 and the direction F2 along the bottom surface, and the large air in the drying chamber 22 is blown out. The flow is from the opposing side surfaces to the upward flow F1 along the side surface, the flow F3 along the upper surface to the hot air return pipe, and from the opposite side surfaces to the central part along the bottom surface and collides with the central part. The flow becomes F2, and strong hot air is not directly blown to the workpiece, and the heating is as if it wraps the drying chamber 22 from the surroundings. In addition, the flow is complicated by the collision of air at the center of the bottom, and the hot air as a whole becomes hot air. By making the environment of the drying chamber 22 uniform without significantly impairing the drying promoting effect by spraying, the entire work can be dried uniformly.

FIG. 8 shows a front schematic view showing a hot air drying furnace in which only one hot air generator is configured in a modified example of the above embodiment.
When the hot air generator 1 is used as one unit, a blower passage 5 having branches according to the number of flanges 31 (connection portions) of the pair of hot air blowout pipes 3 (4 locations in this example) is provided. , Hot air from one air outlet 14 of the hot air generator 1 is piped so that it can be introduced into each hot air discharge port 32. On the other hand, it is sufficient to provide one flange 41 (connection portion) of the hot air return pipe 4 connected to the exhaust passage 6 in an intermediate portion or the like of the pipe 4, and one exhaust passage 6 is used for the hot air generator 1. It is connected to the suction port 15. In this way, the number of hot air generators 1 to be used may be selected from the relationship between the capacity of the equipment and the capacity of the drying furnace 2, but the configuration can be simplified and the cost can be reduced by using one. Can be done.

9 to 12 show a conveyor furnace type hot air drying furnace according to the second embodiment of the present invention, FIG. 9 is a front view of the entire configuration seen from the inlet direction of the conveyor, and FIG. 10 is a front view. A side view is shown, A is a schematic view showing the flow of hot air outside the furnace with an arrow, and B shows the main body of the furnace. In addition, in order to make it easy to understand the configuration in the heating section area (inside the furnace), the internal configuration of the furnace with a part of the outer wall omitted is described in the drawing.

The hot air drying furnace of this embodiment is a drying furnace that dries the work by hot air heating while the conveyor 8 on which the work is placed and moves passes through the heating section area (inside the furnace) 220 surrounded by the outer wall 210. The hot air generator 10 provided outside the furnace as a heat source, and the inlet 230 and the carry-out port serving as the transport port of the conveyor belt 81 by penetrating the conveyor belt 81 of the conveyor 8 substantially in the center of the furnace 220. An outlet 240 is used as an opening, and the entire periphery of the drying furnace body 20 is surrounded by an outer wall 210 to partition a heating section area, and a blower connecting the hot air generator 10 and the inside 220 of the drying furnace body 20. It was composed of a passage 50 and an exhaust passage 60.

Then, the inside 220 of the drying furnace main body 20 is located in front of the inside of the furnace, which is located below the conveyor belt 81 along the opposite side surface near the bottom surface of the inside of the furnace, which is a supply portion of hot air into the inside of the furnace. From the conveyor belt 81 along the opposite side surface near the upper surface of the furnace, a pair of left and right lower hot air blowout pipes 30a, which are long tubular and are provided from the (inlet side) to the rear (exit side) with almost the full length. A pair of left and right upper hot air blowout pipes 30b, which are long tubular and provided so as to be parallel to the lower hot air blowout pipe 30a located above, and an inside 220 which serves as an air discharge part from the inside of the furnace. A long tubular lower hot air return pipe 40a and an upper hot air return pipe 40b provided so as to be parallel to the hot air blowout pipe 30 along the bottom surface and the central portion in the length direction of the upper surface. Similar to the first embodiment, the blower port 140 of the hot air drying device 10 and the flanges 310 provided on both ends of the hot air blowout pipe 30 are connected by the blower passage 50, while the hot air return pipe 40 is provided. A plurality of flanges 410 (four in this example) and suction ports 150 of the hot air generator 10 are connected by an exhaust passage 60, and the hot air generator 10 and the furnace 220 are configured to circulate and heat hot air. As in the first embodiment, a known device is provided for the temperature sensor, the control device, and the like.

As the hot air generator 10 in the present embodiment, the same one as in the first embodiment may be used in the same manner, but in the present embodiment, the same two hot air generators (10a, 10b) are used, and one of the hot air generators 10a is used. Is connected to the air outlet 140a of the device 10a via the lower hot air blowing pipe 30a and the air passage 50a in the furnace 220, and to the suction port 150a of the device 10a via the lower hot air return pipe 40a and the exhaust passage 60a. The device 10b is connected to the air outlet 140b via the upper blow pipe 30b and the air passage 50b, and to the suction port 150b of the device 10b via the upper hot air return pipe 40b and the exhaust passage 60b.

As described above, the drying furnace main body 2 is formed in a box shape in which the entire circumference excluding the inlet 230 and the outlet 240 through which the conveyor belt 81 passes is covered with an outer wall 210 containing a heat insulating material, and the inside thereof is a heating compartment area. (Inside the furnace) 220. If the openings serving as the inlets 230 and 240 are formed as small as possible within the range through which the conveyor belt 81 on which the work is placed can pass, it is possible to suppress the release of heat in the furnace to the outside. Then, a conveyor belt 81 on which the work is placed is arranged so as to pass through the vicinity of the center of the furnace 220, and pulleys 82 for driving the conveyor belt 81 are provided at both ends extending outside the furnace. Formed. The conveyor 8 of this example exemplifies the simplest configuration, and is not limited to the one using a belt as long as it can carry a work and convey the 220 in the furnace, for example, any form such as a roller conveyor. You may use the conveyor of.

FIG. 11 shows the hot air blowing pipe of this embodiment, where A is a lower hot air blowing pipe and B is an upper blowing pipe.
The hot air blowing pipe 30 of the present embodiment is formed as a long hollow tubular body made of stainless steel or the like with both ends closed like the hot air blowing pipe 3 of the first embodiment, and is formed on a side surface near the bottom surface of the furnace 220. In the lower hot air blowing pipe 30a arranged along the hot air blowing pipe, a plurality of hot air blowing ports arranged side by side at appropriate intervals along the upper surface of the furnace and the side surface facing the facing surface are blown out. Ports 320a (upper surface side) and 320b (side surface side) are provided as holes, while the upper blowout pipe 30b arranged along the side surface near the upper surface is provided on the side surface facing the furnace when arranged. Along the same way, a plurality of hot air outlets 320c arranged at appropriate intervals are provided as holes, but in this example, the direction in which the hot air outlet 320c of the upper hot air outlet pipe 30b is slightly tilted toward the upper surface side from the direction parallel to the upper surface. Set to.

By setting the hot air outlet 320 at the position as described above, the hot air introduced into the lower outlet pipe 30a is discharged above the furnace 220 and in the direction parallel to the bottom surface and introduced into the upper outlet pipe 30b. The generated hot air is discharged slightly upward from parallel to the upper surface. (See FIG. 12) Here, by directing the discharge of hot air from the upper blowout pipe 30b slightly upward, it is possible to prevent strong hot air from directly blowing onto the work placed on the conveyor belt 81. In this example, the flange 310, which is a connection portion with the blower passage 50 and serves as an introduction port for hot air from the hot air generator 10, has hot air outlets 320b along the bottom surface and the upper surface at both ends of the hot air outlet pipe 30. It is provided on the back surface of the 320c.

The hot air return pipe 40 is also formed as a long hollow tubular body like the hot air return pipe 4 of the first form, but in this embodiment, only the hot air return pipe 40a provided in the center of the upper surface of the furnace 220 is provided. Instead, a hot air return pipe 40b of the same form is also provided in the center of the bottom surface, and air exhaust ports 420a (bottom side) that serve as outlets for used air from the furnace 220 are provided on both sides of each return pipe 40. ), 420b (upper surface side) are provided as a plurality of arranged holes. The flange 410 or the like that serves as a connection portion of the hot air return pipe 40 with the exhaust passage 60 may be the same as that of the hot air drying furnace of the first aspect. (See Fig. 5)

The blower passage 50 and the exhaust passage 60 may also be formed by connecting the hot air generator 10, the hot air blowout pipe 30, and the hot air return pipe 40 in the same manner as in the blower passage 5 and the exhaust passage 6 of the first aspect. Or, in this example, as described above, two hot air generators are used, one of the hot air generators 10a is the lower hot air blowing pipe 30a and the lower hot air return pipe 40, and the other hot air generator 10b is the upper hot air blowing pipe. It is connected to 30b and the upper hot air return pipe 40b via an air passage 50 and an exhaust passage 60, respectively.

From the above, when the piping between the hot air generator 10 and the furnace 220 and the flow of hot air are summarized, the hot air discharged from the air outlet 140a of the first hot air generator 10a is the first air blown into four branches. On the inlet side (carry-in side 230 of the conveyor 8) and the outlet side (carry-out side 240 of the conveyor 8) of the lower hot air blowing pipes 30a facing each other along both side surfaces near the bottom surface of the furnace 220 through the passage 50a. It is introduced into the flange 310 and is discharged upward from the hot air outlet 320a in the furnace and from the hot air outlet pipe 320b in the direction along the bottom surface of the furnace. On the other hand, the hot air discharged from the air outlet 140b of the second hot air generating measure 10b passes through the second air passage 50b branched into four and faces each other along both side surfaces near the upper surface of the furnace 220. It is introduced into the flanges 310 on the inlet side and the outlet side of each of the upper hot air blowing pipes 30b, and is discharged from the hot air blowing port 320c toward the slightly upper surface of the furnace 220 in the direction along the upper surface. Further, the air in the furnace 220 is supplied from the air exhaust port 420a of the hot air return pipe 40a on the bottom surface side and the air exhaust port 420b of the hot air return pipe 40b on the upper surface side to the hot air return pipe 60a (bottom side) 60b (top surface side). Through, they are returned to the suction port 150a of the first hot air generator 10a and the suction port 150b of the second hot air generator 10b, respectively, and circulated. The arrangement of the hot air blowout pipe 30, the hot air return pipe 40, the number of hot air generators 10, and the like may be appropriately set according to the size of the furnace and the work.

FIG. 12 shows the main flow of hot air in the furnace of this embodiment.
In the hot air drying furnace of this embodiment, a pair of hot air blowing pipes 30 are placed on the bottom of the furnace 220 and two facing surfaces of the upper portion, and a pair of hot air returning pipes 40 are placed on the bottom surface and the upper surface of the furnace 220 in the lengthwise direction. Since the hot air outlet 320 of the lower hot air outlet pipe 30a is arranged along the upper surface 320a and the opposite side surface 320b, the hot air introduced into the hot air outlet pipe 30a is above the furnace 220. Since the hot air outlet 320c of the upper hot air outlet pipe 30b is arranged slightly upward from the opposite side surface, the hot air is blown out in the direction F20 along the bottom surface of the F10 and the hot air outlet pipe 30b. Is blown out in the direction F30 slightly toward the upper surface in the furnace, and the large air flow in the furnace 220 is from the opposite bottom side surface to the upward flow F10 along the side surface, from both side surfaces to the bottom surface. The flow F20 is directed toward the hot air return pipe 40a in the central portion, and the flow F30 is directed toward the hot air return pipe 40b in the central portion along the upper surface from the opposite upper side surface. Instead, the work is heated so as to surround the work and wrap the inside of the furnace 220. In addition, the flow is complicated by the collision of air from both sides toward the center, and the drying promotion effect due to the blowing of hot air is not significantly impaired as a whole, and the environment inside the furnace is made uniform. , The entire work can be dried uniformly.

1.10. Hot air generator 11. Motor 12. Blower 13. Heater 14.140. Blower 15.150. Suction port 16. Fresh air intake 2.20. Drying furnace 21.210. Outer wall 22.220. Drying room 23. Door 3.30. Hot air blowout tube 31.310. Flange (connection part)
32.320. Hot air outlet 4.40. Hot air return pipe 41.410. Flange (connection part)
5.50. Blower passage 51. Connection part 6.60. Exhaust passage 7. Bogie 71. Shelf 8. Conveyor 81. Conveyor belt 82. pulley

Claims (5)

In a drying furnace that introduces hot air into the heating area to dry the work to be heated, the hot air drying device placed outside the area is provided facing each other along the facing side surfaces near the bottom surface in the area (inside the drying oven). A hot air blowing part including a hot air discharge port arranged in a row from the front to the rear, and a hot air supply that is connected to the vicinity of both ends of the hot air blowing part and introduces heated air from the hot air generator. Hot air including a hot air outlet that is provided in parallel with the hot air blowing part in the passage and the center of the upper surface that serves as an air exhaust part from the inside of the drying furnace to the outside and is arranged in a row from the front to the rear. It is configured to have a return port and an exhaust passage, and the discharge port is an upper surface facing upward along the side surface of the furnace when the hot air blowing portion is set in the drying furnace, and a facing side surface along the bottom surface of the furnace. The hot air blown out from the discharge port of the hot air blowing part is provided on the side surface facing the furnace, and the discharge direction of the hot air is not directly directed to the work, and is parallel to the upper surface and the bottom surface from the side surface of the wall surface in the drying furnace, or slightly on the wall surface. A hot air drying furnace characterized by being set in almost parallel directions. The hot air blowing portion is provided not only along the facing side surface near the bottom surface but also facing along the facing side surface near the upper surface in the drying furnace, and is provided near the upper surface. The hot air drying furnace according to claim 1, wherein the hot air blowing portion is provided only on the side surface facing the opposite side surface along the upper surface of the furnace when the hot air blowing portion is set in the drying furnace. The hot air drying furnace according to any one of claims 1 to 2, wherein the hot air return port is provided in the central portion of the upper surface in the drying furnace and also in the central portion of the bottom surface. The drying furnace is a conveyor furnace that dries the work with hot air while the conveyor on which the work to be heated passes through the compartment (inside the drying furnace). The hot air drying furnace according to any one of claims 1 to 3, wherein the inside of the drying furnace is formed by surrounding the entire circumference with an outer wall except for the opening, and the conveyor belt is provided in a substantially central portion of the drying furnace. The hot air blowing portion provided facing the facing side surface of the bottom surface portion of the conveyor furnace is located below the conveyor belt of the conveyor furnace, and is provided facing the facing side surface of the top surface vicinity portion. The hot air drying furnace according to claim 4, wherein the blowing portion is located above the conveyor belt.

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