JP2017032233A - Hot blast drying furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drying furnace for drying a work piece to be heated while feeding hot blast into a heated segment in which a temperature of atmosphere in the heated segment is unified, drying quality is improved and it can also be applied to a workpiece influenced by blast pressure such as powder or the like.SOLUTION: A hot blast drying furnace is constituted by comprising: a hot blast drying device 1 installed outside a heating segment; a hot blast blowing-out part 3 having hot blast blowing-out ports 32 arranged along one wall surface or a plurality of wall surfaces in a defined segment (in a drying furnace) and arranged in rows from the forward side to the rear side; a hot blast supply flow passage 5 for feeding heated air from a hot blast generating device to the hot blast blowing-out part; a hot blast return port 42 becoming a discharging part for air from inside of the drying furnace to outside; and a discharging passage 6. Then, a discharging direction of hot blast from the blowing-out ports 32 of the hot blast blowing-out part 3 is not directly set to flow toward work pieces, but set to flow in parallel with the wall surfaces in the drying furnace or in a substantial parallel direction slightly toward the wall surfaces.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a hot air drying furnace that dries a heated work housed in a furnace with hot air introduced from a hot air generator.

  A hot-air drying furnace that introduces hot air from a hot-air generator into a heating compartment and dries a workpiece to be heated by the synergistic effect of heat and wind is recognized as having a high drying effect. When the used air is blown onto the workpiece and the used air is discharged from the exhaust port, the temperature distribution in the furnace increases greatly due to the specification of the flow of hot air in the furnace and the influence of the work. Since drying is not possible, many drying furnaces have been proposed that attempt to suppress this variation and make the furnace environment uniform.

  For example, a box configured to provide hot air outlets and hot air inlets in a furnace body containing a workpiece to be heated, blow hot air generated by a hot air generator into the furnace, and return used hot air to the hot air generator In this type of drying furnace, a shielding plate is installed at a position along the side of the material to be dried in the furnace, and an in-furnace fan is formed in the space opposite to the material to be dried across the shielding plate. Regardless of the distance from the hot air outlet through the furnace fan and the shielding plate, from the drying furnace of Patent Document 1 and the lower part of the drying chamber which tried to make the air velocity of the hot air uniform in any part of the material to be dried As a dryer that attempts to stabilize the quality of the discharge of hot air blown up and discharged into the drying chamber and stabilize the drying quality, an adjustment plate for adjusting the amount of hot air is installed in the hot air passage at the bottom of the drying chamber, and a furnace Discharge port for hot air toward the top The composed hole rectifying plate is provided which is provided, the adjusting plate by a dryer, such as in Patent Document 2 attempts to allocate adjusted blown up discharge amount of hot air due to changing a part of the flow of hot air has been proposed.

  In addition, instead of a box-type closed hot air drying furnace, hot air is used for a conveyor furnace that dries while moving a workpiece.For example, an infrared source is arranged vertically away from the conveyor running path in the furnace. A conveyor furnace as in Patent Document 3 is proposed, in which hot air from a hot air generator is blown toward the conveyor in the furnace and at the same time the hot air in the furnace is forcibly stirred by a fan to control the temperature. Yes.

JP-A-6-34268 JP 2010-249469 A JP 2000-160260 A

  In these furnaces, the issue is how to supply uniform hot air to the heated work in the heating zone (for example, in the furnace) and keep the temperature in the furnace stable. Try to make the hot air velocity uniform, try to distribute and adjust the discharge rate of hot air using the adjustment plate or rectifying plate, or perform forced stirring using a stirring fan in parallel with the use of an infrared source. However, in the furnace, the environment such as the air flow changes depending on 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.

  Speaking of hot air drying ovens, naturally, hot air is blown onto the workpiece to be heated and dried, so that the workpiece may be light, such as powder, blown by the wind, or deformed by wind pressure. What was not the target of the hot air drying furnace.

  Therefore, the present invention adjusts the flow of hot air introduced from the hot air generator to make the atmosphere temperature of the heated section where the heated workpiece is accommodated or installed, resulting in improved dry quality of the workpiece. That was the issue.

  Moreover, it was made into the subject to provide the hot air drying furnace which can be applied also to the to-be-heated workpiece | work which receives influence by wind pressure, such as a powder, although it is a hot air drying furnace.

  The hot air drying furnace of the present invention is for introducing hot air into a heating compartment to dry a workpiece to be heated. A hot air drying device arranged outside the heating compartment, and one or a plurality of wall surfaces in the compartment (in the drying furnace) A hot air blowing portion including hot air outlets arranged in a row from the front to the rear, a hot air supply passage for introducing heated air from the hot air generator to the hot air blowing portion, and drying It comprises a hot air return port serving as an air exhaust unit from the inside of the furnace to the outside, and an exhaust passage, and the discharge direction of the hot air from the discharge port of the hot air blowing unit does not directly face the work, but in the drying furnace It is set so as to be parallel to the wall surface or slightly parallel to the wall surface.

Moreover, it is preferable that each part is comprised or formed as follows.
-The said hot-air blowing part is arrange | positioned facing the side surface which faces in a drying furnace.
-The said hot-air blowing part is arrange | positioned along the side surface near the bottom face in a drying furnace. At this time, the discharge direction of the hot air from the hot air blowing section is set to be upward along the side surface and parallel to the bottom surface along the bottom surface or slightly parallel to the bottom surface slightly.
The hot air blowing part is arranged along the side surface near the top surface in addition to the side surface near the bottom surface in the drying furnace. At this time, the discharge direction of the hot air from the hot air blowing portion disposed along the vicinity of the upper surface is set to be parallel to the surface along the upper surface or slightly parallel to the upper surface.
The hot air blowing portion is formed as a hot air blowing tube formed in a long tubular shape, and the discharge ports are arranged side by side on the blowing tube.
The hot air return port is arranged side by side on a hot air return pipe formed in a long tubular shape.
The hot air outlet is formed by either a slit formed on a substantially straight line along the hot air blowing portion, or a plurality of holes or nozzles provided at intervals.
-The said hot air return port is formed in the upper surface center part in a drying furnace in parallel with the said hot air blowing part.
-The connection part of the said hot air blowing pipe and the said ventilation path is set to the both end vicinity position of this hot air blowing pipe.
-One or more hot air generators are provided.

(Function)
According to this means, along with the inner wall surface of the drying furnace, the hot air discharged from the hot air discharge port arranged from the front to the rear along the wall surface in the heating zone is not directly blown to the workpiece to be heated. Because it is set to be parallel or slightly parallel to the wall surface, strong hot air is not blown against the work, and the strong flow of hot air in the drying furnace is the flow along the inner wall around the furnace. Become.

  For example, a hot air blowing part is provided facing the side surface in the vicinity of the bottom surface in the drying furnace facing from the front to the rear, and the discharge direction from the discharge port is directed upward and along the side surface in the drying furnace. Set in a direction parallel to the surface, and provided with a hot air return port in the center of the upper surface of the drying furnace in parallel with the hot air blowing portion, the hot air discharged from the hot air discharge port is fast and large flow Rises along both side surfaces in the drying furnace, and flows toward the hot air return portion on the top surface portion and flows from both side surfaces on the bottom surface in the furnace toward the center 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 and heated from the surroundings in the heating zone.

The present invention is not based on the idea of drying by blowing hot air directly onto the workpiece to be heated in the conventional hot air drying furnace, but is based on the idea of making the environment in the drying furnace uniform using hot air. By discharging the hot air along the inner wall surface, it is possible to perform heating so as to wrap the workpiece 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 atmosphere temperature in the heating compartment where the heated workpiece is accommodated or installed is made uniform. As a result, the dry quality of the workpiece can be improved.

  In addition, although it is a drying furnace that uses hot air, it can also be applied to lightweight workpieces such as powders or those that change due to wind pressure as strong hot air is not blown to the workpiece to be heated. it can.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of an overall configuration showing a box-type hot air drying furnace according to a first embodiment of the present invention (a view seen from a door direction). 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 | tube of the said form. The schematic diagram which shows the motion of piping of the said form and the air in piping. The schematic diagram which shows the main motion 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 used the hot air generator as one unit with the modification of the said form. The front view (figure seen from the entrance direction side) which shows the composition of a conveyor furnace type hot-air drying furnace in a second embodiment of the present invention. In the side view of the said form, the schematic diagram which shows the flow of the 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 motion 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 entire configuration. FIG. 2 shows a side view thereof. For the sake of easy understanding, FIG. 1 shows a furnace configuration in which the door is omitted, and in FIG.
The hot-air drying furnace of this embodiment is a box-shaped drying furnace 2 that is used by being housed in a drying chamber 22 in a mode in which a work is placed on a shelf 71 provided in a plurality of stages and mounted on a carriage 7 and is provided outside the drying chamber. A plurality of hot air generators 1 (in this example, four (1a to 1d) are used) and a drying furnace body 2 into which the hot air of the hot air generator 1 is introduced are provided in the drying chamber 22 near the bottom. A pair of left and right long hot air blowing pipes 3 arranged in a length that extends substantially from the front to the back of the room along the opposing side surfaces, and the center of the upper surface (ceiling surface) of the drying chamber 22 And a long hot air return pipe 4 provided with a full length from the front to the rear of the room so as to be parallel to the hot air blowing pipe 3. And the hot air drying apparatus 1 and the hot air blowing pipe 3 are connected by the ventilation path 5, and the connection part 51 of the blowing path 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 and circulated and heated with hot air. It should be noted that a temperature sensor, a temperature setting, and a control device which are naturally installed as a drying furnace may be provided with known devices at appropriate positions.

FIG. 3 shows an example of a hot air generator used in the above-described form.
Since the hot air generator 1 may be a conventional hot air generator, a detailed description of the configuration and structure is omitted. However, the blower 12 is activated 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 through the air suction port 15, and the taken-in air is heated while passing through the heater 13 and is forcibly discharged from the blower port 14 by the blower 12. Then, the hot air discharged from the blower port 14 passes through the blower passage 5 and is discharged from the hot air discharge port 32 of the hot air blowing tube 3 into the drying chamber 22. Further, in this example, a part of the heated air in the drying chamber 22 is collected 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. Yes. 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 exhaust air from the drying chamber 22 but also fresh air can be taken in. In addition, in the hot air generator 1 of this example, it demonstrates as an apparatus which provided the ventilation port 14 in the upper part of the front surface, and the suction port 15 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 form are placed on the upper and lower surfaces of the drying furnace body 2 (the front surface is provided with the air blowing port 14 and the rear surface is the rear surface). The hot air generated from the air blowing ports 14 passes through each of the connected air passages 5 and is formed as a pair of hot air. The blower pipes 3 are connected so as to be introduced one by one into four connection flanges 31 in the vicinity of both ends of the blowout pipe 3 (two at one place). On the other hand, 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. The air inlet 15 is connected via a filter (not shown). In this example, the intake port 15 is formed in a bifurcated manner, and one of the intake ports 15 is opened to the outside as a fresh air intake port 16. In this embodiment, four hot air generators 1 are used. However, as long as the capacity of hot air can be secured, two air passages may be formed as two, and four 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 piping of the air passage 5 and the exhaust passage 6 to be short by arranging the hot air blowing pipes 3 and the like described later. is there. 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 cart 7 loaded with works on a plurality of shelves 71 inside the drying furnace main body 2 formed in a box shape by the outer wall 21 and the front door 23. The space 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 a hot air blowing tube of this embodiment.
The hot air blowing pipe 3 is formed in the vicinity of the bottom of the drying chamber as a hollow tubular body made of stainless steel or the like that is set to a length that is substantially full from the front to the rear along both opposing side surfaces, and whose both ends are closed. . Although the shape and the like are not specified, the present example was formed in a rectangular parallelepiped. And when it installs in the corner | angular part of the bottom face of the drying chamber 22, it becomes a blower port of the hot air to the drying chamber 22 arrange | positioned in the upper surface of this hot-air blowing pipe 3 and the side surface used as an opposing surface side at an appropriate space | interval. A plurality of holes were provided to form the hot air outlet 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 a direction parallel to the surface along the bottom surface. Become. (See Figure 7)

  Also, the hot air intake port from the hot air generator 1 to the hot air blowing pipe 3, that is, the connecting portion 51 to the air passage 5 is provided as a flange 31 in the vicinity of both ends of the hot air blowing pipe 3 as described above. In addition, since the amount of air discharged from the hot air discharge port 32 varies depending on the distance from the flange 31 due to the nature of the fluid flow, the arrangement considering the discharge balance, such as forming the size of the hole as large as the end portion. , It is preferable to set. Further, the hot air blowing portion including the hot air discharge port 32 is not limited to the tubular body (hot air blowing tube 3), and may be provided as a space like an elongated room on the side surface of the drying chamber, for example. In addition, the hot air discharge port 32 is not limited to the hole of the present example, and may be a long slit or a plurality of nozzles appropriately arranged.

FIG. 5 shows a hot air return pipe of this embodiment.
The hot air return pipe 4 is a hollow made of stainless steel, etc., which is set at a central portion of the upper surface (ceiling surface) of the drying chamber 22 so as to extend from the front to the rear in parallel with the hot air blowing pipe 3 and is almost full of the room. In this example, it was formed as a rectangular parallelepiped. And the flange 41 which connects the other end of the exhaust_gas | exhaustion path | route 6 which four units | sets of the hot air generators 1 connect is provided in four places, providing an appropriate space | interval in the upper surface of this hot air return pipe | tube 4, and also on both sides | surfaces A plurality of holes serving as exhaust ports for used air from the drying chamber 22 arranged at appropriate intervals were provided as air exhaust ports 42. At this time, the area of the entire air exhaust port is preferably formed equal to or larger than that of the air outlet 32 in consideration of an increase in air pressure in the drying chamber. Further, a separate exhaust port may be provided in the drying chamber 22 for adjusting the pressure in the chamber or promoting cooling after use.

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

  And arrangement | positioning in the furnace of a hot-air blowing part and exhaust part, such as a hot-air blowing pipe 3 and a hot-air return pipe 4, is not limited to this form, The inside of the furnace of the present invention depends on the size and form of the furnace. It 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 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 on both side surfaces instead of the side surface near the bottom surface. Similarly, the setting position of the hot air return pipe 4 may be provided at the center of the bottom surface, and the arrangement, the discharge direction, and the like may be set as necessary.

  The air passage 5 is a heat-resistant flexible hose that connects the hot air generator 1 and the hot air blowing tube 3, and is provided near the flange of the air blowing port 14 of the hot air generating device 1 and both ends of the hot air blowing tube 3. It is formed by connecting both ends to the flange 31. And as above-mentioned, each of the four hot-air generators 1 is connected with the connection part 51 of the both ends vicinity of the two hot-air blowing pipes 3 which oppose, respectively, and the hot air from the hot-air generator 1 comprised by hot air is comprised. This is a passage to be sent to the blowing pipe 3. The air passage 5 may pass 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 flanges 41 provided on the upper surface of the hot air return pipe 4, and both ends of the flange of the intake port 15 of the hot air generator 1. And 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, which are respectively connected to the four hot air generators 1a to 1d.

FIG. 6 is a schematic diagram showing the movement of air in the piping and the piping connecting the hot air generator of this embodiment and the drying chamber.
The piping of the hot air generator 1 and the drying chamber 22 and the movement of the hot air are summarized as follows. 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 that returns from the room 22 to the hot air dryer 1 through the hot air return pipe 4 and the exhaust passage 6.

  In the present embodiment, four hot air generators 1 constituting the hot air supply route are arranged in the width direction of the upper portion of the drying furnace body 2, while the hot air blowing pipe 3 is arranged at the bottom of the drying chamber 22. A flange 31 serving as a hot air intake port is disposed in the vicinity of both end portions, which are set in the length direction on both opposing side surfaces in the vicinity. For this reason, the four hot air generators arranged in parallel are set alternately on the front and rear surfaces as an arrangement for shortening and efficiently setting the air passage 5 connecting the air outlet 14 of the hot air generator 1 and the flange 31 of the hot air blowing pipe 3. did. And in this example, the ventilation channel | path 5 connected to the ventilation port 14 of the hot-air generator 1a by which the ventilation port 14 located in the leftmost side seeing from the front of a furnace is arrange | positioned in the front side is on the left side of a furnace. Connected to the flange 31a on the front side of the arranged hot air blowing pipe 3, and similarly, the hot air generator provided with the air outlet 14 on the rear surface side at the second position from the left so as to make a connection for setting the air passage 5 short. 1b is a left-side rear flange 31b, a hot-air generator 1c that is second from the right and has a blower port 14 on the front side is a right-front flange 31c, and a hot-air generator that is provided with a blower port 14 on the rightmost side and the rear side. 1d is connected to a flange 31d on the right rear side.

  On the other hand, the suction port 15 located on the rear surface opposite to the air blowing port 14 of the hot air generator 1 and the four flanges 41 serving as the hot air discharge ports of the hot air return pipe 5 disposed in the longitudinal direction on the upper surface of the drying chamber 22. The exhaust passage 6 connected to the suction port 15 of the hot air generator 1a is connected to the innermost flange 41a of the hot air return pipe 4, from the viewpoint of setting the exhaust passage 6 short and efficiently, 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 exhaust passage 6 is set to be short. Connected to the second flange 41d. In addition, this arrangement | positioning showed the optimal arrangement | positioning from the relationship of the hot-air generator of this form, and a furnace, and the arrangement | positioning suitable for the form should just be selected in other forms.

FIG. 7 is a schematic diagram showing the main hot air flow in the drying chamber of this embodiment.
In the hot air drying furnace of this embodiment, hot air generated from the hot air generator 1 is introduced into the hot air blowing pipe 3 through the blower passage 5 and discharged into the drying chamber 22 from the hot air discharge port 32, but is introduced into the blowing pipe 3. The hot air is supplied from the vicinity of both ends (flange 31) of the blowing pipe 3 so that the hot air flows from both ends of the blowing pipe toward the center, hits at the center, and within the blowing pipe 3 The flow of air is complicated, and the size of the hot air discharge port 32 is changed depending on the location, etc., so that hot air discharged from each blowout port 32 is introduced with air from one direction, for example. It can be expected to be more uniform than

  Further, the hot air blowing pipe 3 is installed on 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 an upper surface 32a of the blowing pipe. Since the hot air introduced into the blowout pipe 3 is blown out in the direction F2 along the bottom F1 and the bottom of the drying chamber 22, The flow flows from the opposite side surfaces to the upper side along the side surface F1, the flow F3 from the opposite side surfaces to the hot air return pipe, and from the opposite side surfaces to the central portion along the bottom surface, and collides with the central portion. The flow is F2, and it does not blow strong hot air directly on the work piece, it is heated as if it envelops the drying chamber 22 from the surroundings, and the flow is caused by an air collision at the bottom center. Becomes coarse as a whole, without significantly impairing the drying accelerating effect by blowing hot air, by environmental drying chamber 22 is made uniform, which is assumed to be able to dry the entire workpiece uniformly.

FIG. 8 is a schematic front view showing a hot air drying furnace having only one hot air generator as a modification of the embodiment.
When the hot air generator 1 is used as a single unit, the air passage 5 having branches according to the number of flanges 31 (connection portions) of the pair of hot air blowing pipes 3 (four in this example) is provided. The hot air from the air blowing port 14 at one location of the hot air generating device 1 is piped so as to be introduced into each hot air discharge port 32. On the other hand, it is only necessary to provide one flange 41 (connecting portion) of the hot air return pipe 4 connected to the exhaust passage 6 at an intermediate portion of the pipe 4 or the like. Connected to the suction port 15. Thus, the number of hot air generators 1 used may be selected based on the relationship between the capacity of the apparatus and the capacity of the drying furnace 2, but the configuration can be simplified and the cost can be reduced by using a single unit. Can do.

  9 to 12 show a conveyor furnace type hot-air drying furnace according to a second embodiment of the present invention. FIG. 9 is a front view of the entire configuration as viewed from the entrance direction of the conveyor. The side view is shown, A is a schematic diagram in which piping is omitted, the flow of hot air outside the furnace is indicated by arrows, and B is the main body portion of the furnace. In order to facilitate understanding of the configuration in the heating compartment (inside the furnace), the internal configuration of the furnace in which a part of the outer wall is omitted is described in the drawings.

  The hot air drying furnace of this embodiment is a drying furnace in which the work 8 is dried by hot air heating while the conveyor 8 on which the work is placed 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, the inlet 230 and the outlet serving as the transport port of the conveyor belt 81 through the conveyor belt 81 of the conveyor 8 substantially in the center of the furnace 220 The outlet 240 is an opening, and the entire other periphery is surrounded by the outer wall 210 to divide the heating compartment, and the blower that connects the hot air generator 10 and the furnace 220 of the drying furnace body 20 is connected. The passage 50 and the exhaust passage 60 are configured.

  And in the furnace 220 of the drying furnace main body 20, the front of the furnace located below the conveyor belt 81 along the opposite side surface near the bottom of the furnace, which serves as a supply section of hot air into the furnace. From the conveyor belt 81 along a pair of left and right lower hot air blowing pipes 30a, which are provided in a substantially full length from the (inlet side) to the rear (exit side), and opposite side surfaces near the upper surface in the furnace. A pair of long tubular left and right upper hot air blowing tubes 30b, which are provided to be parallel with the same length as that of the lower hot air blowing tube 30a, and a furnace 220 serving as an air discharge unit from the furnace. A long tubular lower hot air return pipe 40a and an upper hot air return pipe 40b are provided so as to be parallel with the same length as the hot air blowing pipe 30 along the bottom surface and the central portion in the longitudinal direction of the upper surface. Provided As in the first embodiment, the air outlet 140 of the hot air drying apparatus 10 and the flanges 310 provided at both ends of the hot air blowing pipe 30 are connected by the air passage 50, while the flanges provided in the hot air return pipe 40 are plural. 410 (four in this example) and the suction port 150 of the hot air generator 10 are connected by the exhaust passage 60, and hot air circulation heating is performed in the hot air generator 10 and the furnace 220. As in the first embodiment, known devices are provided for the temperature sensor, the control device, and the like.

  The hot air generator 10 in this embodiment may be the same as that in the first embodiment, but in this embodiment, the same two hot air generators (10a, 10b) are used, and one device 10a is used. Is connected to the air outlet 140a of the apparatus 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 apparatus 10a via the lower hot air return pipe 40a and the exhaust air passage 60a. The apparatus 10b is connected to the blower opening 140b through the upper blow-out pipe 30b and the blower passage 50b, and to the suction port 150b of the apparatus 10b through the upper hot air return pipe 40b and the exhaust passage 60b.

  As described above, the drying furnace body 2 is formed in a box shape in which the entire periphery 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 is a heating compartment. (Inside the furnace) 220. In addition, if the opening part used as the said inlets 230 and 240 is formed as small as possible in the range which can convey the conveyor belt 81 which mounted the workpiece | work, discharge | release to the exterior of the heat | fever in a furnace can be suppressed. A conveyor belt 81 for placing the workpiece is disposed 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 extended to the outside of the furnace. Formed. The conveyor 8 of this example is an example of the simplest configuration. The conveyor 8 is not limited to one using a belt as long as it can load a workpiece and transport the inside of the furnace 220. For example, any form such as a roller conveyor is possible. Alternatively, a conveyor may be used.

FIG. 11 shows the hot air blowing tube of this embodiment, A is the lower hot air blowing tube, and B is the upper blowing tube.
The hot air blowing tube 30 of this embodiment is formed as a long hollow tubular body made of stainless steel or the like whose both ends are closed in the same manner as the hot air blowing tube 3 of the first embodiment. In the lower hot air blowing pipe 30a arranged along the hot air blowing outlet, hot air blowing ports serving as hot air outlets arranged at appropriate intervals along the upper surface of the furnace and the side surface on the opposite surface side are arranged. The openings 320a (upper surface side) and 320b (side surface side) are provided as holes. On the other hand, the upper blowing tube 30b disposed along the side surface in the vicinity of the upper surface is provided with a side surface on the opposite surface side of the furnace. Similarly, a plurality of hot air outlets 320c arranged at appropriate intervals are provided as holes. In this example, the hot air outlets 320c of the upper hot air outlet tube 30b are slightly above the direction parallel to the upper surface. It was set in the direction of tilting 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 in the direction above the furnace 220 and in the direction parallel to the bottom surface and introduced into the upper outlet pipe 30b. The hot air thus discharged is discharged toward the upper side rather than being parallel to the upper surface. (Refer to FIG. 12) Here, the discharge of hot air from the upper blow-out pipe 30b is directed slightly upward, so that strong hot air is not directly blown onto the workpiece placed on the conveyor belt 81. In addition, in this example, the flange 310 which becomes an inlet for hot air from the hot air generator 10 at the connection portion with the air passage 50 is connected to both ends of the hot air outlet tube 30 at the hot air outlet 320b along the bottom surface and the top surface. It is provided on the back surface of 320c.

  The hot air return pipe 40 is also formed as a long hollow tubular body, similar to the hot air return pipe 4 of the first embodiment, but in this embodiment, only the hot air return pipe 40a provided at the center of the upper surface of the furnace 220 is provided. Instead, a hot air return pipe 40b having the same configuration is also provided at the center of the bottom surface, and an air exhaust port 420a (bottom surface side) serving as an exhaust port for used air from the furnace 220 is provided on both side surfaces of each return pipe 40. ), 420b (upper surface side) are provided as a plurality of aligned holes. In addition, the flange 410 etc. used as the connection part with the exhaust passage 60 of this hot air return pipe 40 may be the same as that of the hot air drying furnace of said 1st form. (See Figure 5)

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

  From the above, when the piping and hot air flow between the hot air generator 10 and the furnace 220 are summarized, the hot air discharged from the air outlet 140a of the first hot air generator 10a is divided into four first air blows. Through the passage 50a, on the inlet side (the carry-in side 230 of the conveyor 8) and the outlet side (the carry-out side 240 of the conveyor 8) of each of the lower hot air blowing pipes 30a facing along both side surfaces in the vicinity of the bottom surface of the furnace 220. It is introduced into the flange 310 and discharged from the hot air blowing port 320a upward in the furnace and from the hot air blowing tube 320b in a direction along the bottom surface of the furnace. On the other hand, the hot air discharged from the air blowing port 140b of the second hot air generating means 10b passes through the second air passage 50b branched into four, and faces along both side surfaces near the upper surface of the furnace 220. It is introduced into the flange 310 on each inlet side and outlet side of the upper hot air blowing tube 30b, and discharged from the hot air blowing port 320c toward the upper surface of the furnace 220 in a direction along the upper surface. Further, the air in the furnace 220 flows from the air exhaust port 420a of the hot air return tube 40a on the bottom surface side and the air exhaust port 420b of the hot air return tube 40b on the upper surface side to the hot air return tube 60a (bottom side) 60b (upper surface side). Through 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 circulate. It should be noted that the arrangement of the hot air blowing pipe 30 and the hot air return pipe 40 and the number of hot air generators 10 may be appropriately set depending on the size of the furnace and the workpiece.

FIG. 12 shows the main hot air flow in the furnace of this embodiment.
In the hot air drying furnace of this embodiment, a pair of hot air blowing pipes 30 are provided on the bottom part of the furnace 220 and on both opposite side surfaces of the upper part, and a hot air return pipe 40 is provided at the center of the bottom and top surfaces of the furnace 220 in the longitudinal direction. Since the hot air blowing port 320 of the lower hot air blowing tube 30a is disposed on the upper surface 320a and the opposite side surface 320b, the hot air introduced into the hot air blowing tube 30a is located above the furnace 220. F10 and the hot air blown out in the direction F20 along the bottom surface, and the hot air blowing port 320c of the upper hot air blowing tube 30b is disposed slightly above the opposite side surface, so the hot air introduced into the hot air blowing tube 30b Is blown out in a direction F30 that faces the upper surface of the furnace slightly, and the large air flow in the furnace 220 rises from the opposite bottom side surface along the side surface. The flow F10 toward the center, the flow F20 toward the central hot air return pipe 40a along the bottom surface from both sides, and the flow F30 toward the central hot air return pipe 40b along the upper surface from the opposite upper side surface into the conveyor belt. The work placed on 81 is not sprayed directly, but surrounds the work and heats as if enclosing the furnace 220. In addition, the flow is complicated by the collision of air toward the center from both sides, and the furnace environment is made uniform without significantly impairing the drying promotion effect of hot air blowing as a whole. The entire workpiece can be dried uniformly.

1.10. Hot air generator 11. Motor 12. Blower 13. Heater 14.140. Ventilation opening 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 blowing pipe 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 6.60. 6. Exhaust passage Dolly 71. Shelf 8 Conveyor 81. Conveyor belt 82. pulley

Claims (12)

  In a drying furnace that introduces hot air into the heated compartment to dry the workpiece to be heated, a hot air drying device that is arranged outside the compartment, and one or more walls in the compartment (in the drying furnace) are provided along the front. A hot air blowing section including hot air outlets arranged in a row extending rearward, a hot air supply passage for introducing heated air from the hot air generating device into the hot air blowing section, and air from the inside of the drying furnace to the outside The hot air return port that serves as the exhaust air part and the exhaust passage are configured so that the discharge direction of the hot air blown from the discharge port of the hot air blow part is not directed directly toward the work but parallel to the wall surface in the drying furnace. Alternatively, the hot air drying furnace is set to be slightly parallel to the wall surface.   The hot-air drying furnace according to claim 1, wherein the hot-air blowing section is disposed so as to face the side surfaces facing each other in the drying furnace.   The hot air drying furnace according to claim 1, wherein the hot air blowing section is disposed along a side surface in the vicinity of the bottom surface in the drying furnace.   The hot air discharge direction from the hot air blowing portion arranged along the side surface near the bottom surface is upward along the side surface and parallel to the bottom surface along the bottom surface or slightly parallel to the bottom surface slightly. The hot air drying furnace according to claim 3, wherein   The hot air drying furnace according to claim 3, wherein the hot air blowing section is arranged along a side surface near the bottom surface in the drying furnace and also along a side surface near the top surface.   The hot air discharge direction from the hot air blowing section disposed along the side surface in the vicinity of the upper surface is set to be parallel to the surface along the upper surface or slightly parallel to the upper surface. Hot air drying furnace.   The hot air drying furnace according to any one of claims 1 to 6, wherein the hot air blowing section is formed as a hot air blowing pipe formed in a long tubular shape, and the discharge port is arranged side by side on the blowing pipe.   The hot-air drying furnace according to any one of claims 1 to 7, wherein the hot-air return port is arranged side by side on a hot-air return pipe formed as a long tubular shape.   The hot air drying device according to any one of claims 1 to 8, wherein the hot air discharge port is formed by any one of a slit formed on a substantially straight line along the hot air blowing portion, or a plurality of holes or nozzles provided at intervals. Furnace.   The hot air drying furnace according to any one of claims 1 to 9, wherein the hot air return port is formed in a central portion of an upper surface in the drying furnace in parallel with the hot air blowing section.   The hot air drying furnace according to claim 7, wherein a connecting portion between the hot air blowing pipe and the air passage is set near both ends of the hot air blowing pipe.   The hot air drying furnace according to claim 1, wherein one or a plurality of the hot air generators are provided.

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