JP6856331B2 - Leaf tobacco dryer and its construction method - Google Patents

Description

The present invention relates to a leaf tobacco dryer that introduces high-temperature dry air generated in a hot air generator into a drying chamber to dry leaf tobacco in the drying chamber, and a method for constructing the leaf tobacco dryer.

Conventional leaf tobacco dryers use a hot air generator equipped with an air intake, a blower, a fireplace, and a hot air outlet at the bottom, and blow up hot air blown into the lower space from the hot air outlet to dry the leaf tobacco suspended inside. It has a structure provided with a drying chamber (see Patent Documents 1 and 2). Such a leaf tobacco dryer is usually installed in a pit by digging a pit on the floor in a covered drying facility (the space inside the pit becomes the lower space of the drying chamber), and the door on the front side of the drying chamber is opened. , The leaf tobacco rack on which the leaf tobacco is hung is suspended in multiple stages in the drying chamber, and after the drying operation, the dried leaf tobacco dried leaves are carried out together with the rack.

On the other hand, the leaf tobacco dryer repeatedly takes in the outside air and exhausts the moist air during the drying operation, and the rate of heat loss is relatively large. Therefore, the applicant tried to recover the exhaust heat to improve the thermal efficiency. An energy-saving type dryer (Patent Document 3) was proposed earlier.

JP-A-2007-20511 Jikkenhei 6-70594 Japanese Unexamined Patent Publication No. 2009-160266

When renewing an existing leaf tobacco dryer in the above drying facility, it is desirable that the pit provided on the foundation can be used as it is from the viewpoint of reducing the construction cost. Also, in recent years, in order to consolidate drying facilities, it is often requested to replace a small leaf tobacco dryer with a large leaf tobacco dryer when renewing, but usually, a standard panel is used for the drying room. Due to the increase in size, the drying chamber may not fit into the existing pit (a situation where a new pit is installed or an existing pit is expanded and repaired), and there is a problem that a large leaf tobacco dryer cannot be introduced smoothly. It was.

The present invention has been made in view of the above problems, and provides a leaf tobacco dryer capable of increasing the size of the drying chamber while utilizing the existing pit provided on the foundation of the leaf tobacco drying facility as the lower space, and a construction method thereof. The purpose is to do.

In order to solve the above problems, the leaf tobacco dryer according to the present invention
A hot air generator that heats the outside air taken into the casing from the intake port by a blower with a fireplace to generate high-temperature dry air, and a leaf tobacco are suspended, and the high-temperature dry air generated by the hot air generator is at the bottom. In a leaf tobacco dryer equipped with a drying chamber that is blown up from the space
The drying chamber is placed on a pit panel portion installed in an existing pit drilled in a foundation in a drying facility and placed on the upper surface of the foundation around the pit and joined to the upper part of the pit panel portion. It is composed of a ground base portion and a ground panel portion that is placed on the upper surface of the ground base portion and joined to the ground base portion, and the pit panel portion is composed of a plurality of heat insulating bottom plate panels and side plate panels. the ground panel unit, a heat-insulating a plurality of side plate panels and ceiling panels, the ground-based unit, as the peak Tsu preparative level base in a U-shape or a roughly rectangular shape in plan view around the It is composed of a plurality of base members arranged and having heat insulating properties, and the upper portion of the side plate panel of the pit panel portion and the lower portion of the side plate panel of the ground panel portion are integrally joined to each base member via a joint fitting, and the ground base is said. A straightening vane provided with a large number of through holes is erected between the upper surfaces of the portions via a support member.
Each base member of the above-ground base portion has a width dimension in the width direction of the pit wider than the width dimension of the side plate panel of the above-ground panel portion, and is a support member that supports the straightening vane with the side plate panel of the above-ground panel portion on the outside. Each is installed on the upper surface with the inside facing
Further, each base member of the above-ground base portion is characterized in that the thickness dimension of the pit in the depth direction is the same as the thickness dimension of the bottom plate panel of the pit panel portion.

In the leaf tobacco dryer according to the present invention, the exhaust heat recovery and supply unit is arranged in the casing in the vicinity of the exhaust port and the intake port, and the intake damper that opens and closes the intake port is the intake port and the circulation port. The second feature is that the circulation port is provided with an air volume adjusting plate which is arranged at a substantially intermediate position between the two , adjusts the opening area of the circulation port, and adjusts the air volume circulating in the drying chamber.

The leaf tobacco dryer according to the present invention includes a control unit that controls on / off of burning of the burner to the furnace, and the control unit has a preliminary operation mode in which the burner and the blower are preliminarily operated for a certain period of time, and a drying chamber temperature measured after the preparatory operation. Based on the above, the control unit is provided with a main operation mode in which the burner and the blower are actually operated, and the control unit preliminarily operates the burner and the blower for a certain period of time in the preliminary operation mode and circulates the outside air taken into the casing for a certain period of time in the drying chamber. The burner is stopped and the drying chamber temperature is sampled and measured. When the sampled drying chamber temperature is the operation start temperature, the burner and the blower are switched from the preliminary operation mode to the main operation mode to start the main operation mode. The third feature is that the control is performed according to a preset drying program.

In the present invention, a hot air generator that heats the outside air taken into the casing from the intake port by a blower with a fireplace to generate high-temperature dry air, and a leaf tobacco are suspended and the high temperature generated by the hot air generator is provided. It is a construction method of a leaf tobacco dryer equipped with a drying chamber in which dry air is blown up from the lower space.
A process of installing a pit panel portion consisting of a heat insulating bottom plate panel and a side plate panel in a concave pit drilled in the foundation of the drying facility, and a base member serving as a level base on the upper surface of the foundation around the pit. The process of placing the above-ground base part consisting of the above in a U-shape or a square shape, the process of erection of a straightening vane having a large number of through holes between the upper surfaces of the installed above-ground base part, and the process of placing the above-ground base part. A step of placing a ground panel portion composed of a side plate panel and a top plate panel having heat insulating properties on the upper surface, and a step of joining the pit panel portion and the ground panel portion to the ground base portion to form a drying chamber. It is characterized by including a step of installing the hot air generator adjacent to the drying chamber.

As described above, according to the leaf tobacco dryer according to the present invention, since the drying chamber is separated into a pit panel portion and a ground panel portion, a new pit is newly constructed on the foundation of the drying facility, or an existing pit is expanded and repaired. Instead, the existing pit can be used as it is for the lower space, and the space for suspending leaf tobacco can be expanded to increase the size of the drying chamber.

According to the method for constructing a leaf tobacco dryer according to the present invention, it is not necessary to newly construct a pit or expand and repair an existing pit, so that it is possible to reduce the construction cost associated with the replacement of the leaf tobacco dryer. In addition, since the bit panel portion and the ground panel portion are joined via the ground base portion placed on the upper surface of the foundation around the pit, the ground panel portion is uniformly installed without gaps even on the upper surface of the foundation having an uneven surface. It is possible to ensure high construction quality.

Top view of leaf tobacco dryer according to the present invention, The rear view of the leaf tobacco dryer shown in FIG. A cross-sectional view taken along the line AA of the leaf tobacco dryer shown in FIG. Cross-sectional view of the main part showing the arrangement of the intake damper, BB line cross-sectional view of the leaf tobacco dryer shown in FIG. Enlarged view of the circle C portion shown in FIG. 4, Enlarged view of the circle D portion shown in FIG. It is explanatory drawing which shows the dimensional relationship in a pit panel part.

The best mode for carrying out the present invention will be described with reference to the drawings. In FIGS. 1 and 2, reference numeral 1 indicates a large leaf tobacco dryer, and the leaf tobacco dryer 1 includes a hot air generator 2 and a drying chamber 3.

As shown in FIG. 3, the hot air generator 2 has a blower 5, a heat exchanger 6, and a fireplace 7 arranged inside a casing 4 made of a heat insulating panel. An intake port 8 and a circulation port 9 are provided on the upper portion of the casing 4. The lower portion of the casing 4 is composed of a floor surface panel 21 and a side panel 22 installed in a pit P formed in the foundation G, and a hot air outlet 10 is provided in the lower portion of the casing 4. A burner 11 for a fireplace 7, an exhaust duct 12, and a control unit (control panel) 13 are provided outside the casing 4.

As shown in FIG. 2, an exhaust port 14 is provided next to the intake port 8, and an exhaust heat recovery / supply unit 15 is arranged inside the casing 4 from behind the exhaust port 14 to behind the intake port 8. .. The exhaust heat recovery and supply unit 15 recovers the exhaust heat on the exhaust port 14 side, supplies the recovered exhaust heat on the intake port 8 side, and heats the outside air introduced into the inside from the intake port 8. There is. The exhaust heat recovery and supply unit 15 can be composed of one or a plurality of heat pipes in which the exhaust port 14 side is low and the intake port 8 side is high incline.

An intake damper 16 is provided at the intake port 8. The intake damper 16 opens the intake port 8 to discharge the moist air in the drying chamber 3 from the exhaust port 14, and at the same time introduces fresh outside air into the casing 4, and closes the intake port 8 to enter the drying chamber 3. The air is returned from the circulation port 9 into the casing 4 and circulated in the drying chamber 3. As shown in FIG. 4, the circulation port 9 is provided with an air volume adjusting plate 17. The air volume adjusting plate 17 adjusts the opening area of the circulation port 9 to adjust the air volume circulating in the drying chamber 3, and the air volume in the drying chamber 3 is compared with the air volume sent from the blower 5 to the drying chamber 3 by the rated operation. Adjust the circulating air volume according to the variable volume (when the volume in the drying chamber 3 is small, the opening area of the circulation port 9 is reduced to reduce the circulating air volume, and when the volume in the drying chamber 3 is large, the circulation port The opening area of 9 is increased to increase the circulating air volume), whereby the blowing speed in the drying chamber 3 is made constant. Further, in conjunction with the opening operation of the intake damper 16, the resistivity of the circulating air passing through the circulation port 9 is increased to improve the exhaust efficiency from the exhaust port 14 and the intake efficiency from the intake port 8. Play.

As shown in FIG. 5, the drying chamber 3 is assembled in a box shape from a large number of heat insulating panels straddling two rows of pits P and P drilled in the foundation G, and is installed in each pit P. It is composed of a panel portion 18, a ground panel portion 19, and a ground base portion 20.

As shown in FIGS. 3 and 5, a large number of bottom panels 21 are laid on the bottom surface of each pit P, and the pit panel portions 18 are erected on the upper surface edge portion of the bottom panel 21 along the inner side surface of the pit P. A large number of side panels 22 are arranged, and a lower space S1 through which hot air from the hot air generator 2 is circulated is formed in each pit P.

As shown in FIGS. 3 and 5, the ground panel portion 19 is assembled in a box shape around each pit P via the ground base portion 20, and includes the left and right side panel 23, the top panel 24, and the top panel 24. It is composed of a front door panel 26 with an observation window 25 and a back panel 27. Then, the central partition panel 23A forms a two-row hanging space S2 in which a large number of leaf tobacco 35 is suspended together with the hanging tool 36. The upper part of the back panel 27 is provided with openings communicating with the circulation port 9 and the exhaust port 14, respectively.

The ground base portion 20 serves as a reference for installing the ground panel portion 19, and has a large number of square cross-sections installed in a U-shape or a square shape in a plan view on the upper surface of the foundation G around each pit P. It is composed of a level base member 28. The level base member 28'installed on the upper surface of the foundation G between the two rows of pits P is wide in size to be joined to the side panels 22 and 22 on both sides.

For the panels used for the pit panel portion 18 and the ground panel portion 19, a heat insulating panel having a composite cross-sectional structure in which a heat insulating material (such as styrofoam or urethane foam) is surrounded by a metal material is applied, and level base members 28, 28 are applied. 'Has a heat insulating member with a similar structure. Then, as shown in FIGS. 6 and 7, the side panel 23 of the pit panel portion 19, the level base members 28, 28', and the side panel 23 of the ground panel portion 19 (partition panel 23A, front door panel 26, back panel 27). The level base members 28 and 28'are integrally joined by an L-shaped joining metal fitting 29, respectively.

A sunoco-shaped straightening vane 30 provided with a large number of through holes is erected between the upper surfaces of the level base members 28 and 28'of each pit P via a support member 31. At this time, as shown in FIG. 8, the height of the space in the pit is lowered by ₁ minute of the thickness h of the bottom panel 21 _{with respect to the depth h 0} of the pit P, but the thickness h is the same as _{the thickness h 1 of the bottom panel 21. Since the} straightening vane 30 is erected between the upper surfaces of the level base members 28, 28'having 2, a lower space having the same height h _{3 as the depth h 0 of the pit P can be secured under the straightening vane 30.} Therefore, it is possible to ensure a smooth flow of hot air from the hot air outlet 10 to the lower space and a smooth blowing action from the straightening vane 30 to the leaf tobacco suspension space. On the inner surface of the left and right side panel 23, a hanging rail metal fitting 32 for suspending a hanging tool 36 filled with leaf tobacco (fresh leaves) 35 in two upper and lower stages is attached.

A dry-bulb thermometer 33 and a wet-bulb thermometer 34 are installed near the hot air generator 2 in the vicinity of the rectifying plate 30 of the drying chamber 3. The leaf tobacco drying control is based on the temperature detected from the dry-bulb thermometer 33 and the wet-bulb thermometer 34, and the control unit 13 follows a drying program including each mode of the preliminary operation and the main operation, and the temperature and humidity in the drying chamber 3 are controlled. This is done by controlling the on / off of the burner 11, the operation of the blower 5, and the opening and closing of the intake damper 16 so that the condition maintains the target value.

Next, the construction method of the leaf tobacco dryer 1 configured as described above will be described.

First, a large number of bottom panels 21 are laid on the bottom surface of the existing two rows of pits P, and a large number of side panels 22 are installed on the upper surface of the bottom panel 21 along the inner side surface of the pit P over the entire circumference. Then, the pit panel portion 18 and the lower portion of the casing 4 are formed.

Next, a large number of level base members 28, 28'are placed in a U-shape on the upper surface of the foundation G around each pit P in a plan view, and the joint fitting 29 is used to form each pit panel portion 18. Each side panel 22 and the level base members 28, 28'are joined to form the level base portion 20.

Next, the aggregate 37 (struts, studs, and beams) of each drying chamber 3 is installed on the upper surface of the foundation G around each pit P, and the side surface on the upper surface of each level base member 28, 28'inside the aggregate 37. The panel 23, the front panel 26, and the back panel 27 are placed, and the panels 23, 26, 27 and the level base members 28, 28'are joined to each other by using the joining metal fitting 29. In addition, a large number of top panels 24 are erected on the upper ends of the panels 23, 26, and 27 to form the ground panel portion 19.

Since the drying chamber 3 is separated into a pit panel portion 18 installed inside the pit P and a ground panel portion 19 arranged above the ground portion of the pit P, the leaf tobacco hanging space of the drying chamber 3 is irrespective of the size of the pit P. The size of the drying chamber 3 can be increased while the existing pit P can be used as it is (without expanding and repairing the existing pit P).

Next, a large number of straightening vanes 30 are erected between the upper surfaces of the level base members 28 and 28', and the suspension rail metal fittings 32 are attached to the inner surface of each side panel 23.

After that, for the back panel 27 of the drying chamber 3, the casing 4 and each device constituting the hot air generator 2, that is, the fireplace 7 and the burner 11, the heat exchanger 6 and the blower 5, the exhaust heat recovery and supply unit 15, and the intake air. The damper 16 and the control unit 13 are attached to the inside and outside of the casing 4 to form the hot air generator 2. Further, a dry-bulb thermometer 33 and a wet-bulb thermometer 34 are installed near the rectifying plate 30 in the drying chamber 3, and necessary wiring is provided between the control unit 13 and the dry-bulb thermometer 33.

Since roof support members 38 having different heights are attached and supported on the aggregate 37, the roofing material of the drying facility can be supported at the upper end of each roof support member 38.

According to the leaf tobacco dryer 1 described above, since the level base portion 20 is interposed between the pit panel portion 18 and the ground panel portion 19, both side panels of the ground panel portion 19 are matched to the width dimension of the level base 20. The inner width dimension between 23 and 23 is expanded, or the depth dimension between the front door panel 26 and the back panel 27 is expanded, and the pit P is used as it is as the lower space S1 for hot air flow while the leaf tobacco suspension space S2 is used. It is possible to expand the volume of the drying chamber 3 to accommodate the increase in size of the drying chamber 3.

Further, since the level base members 28, 28'are installed on the upper surface of the foundation G, the ground panel portion 19 is installed at a uniform level on the upper surface of the foundation G having an uneven surface via the level base members 28, 28'. The drying chamber 3 can be easily constructed, and the level base portion 20 is made of a heat insulating member, so that each internal space of the bit panel portion 18 and the ground panel portion 19, that is, the drying chamber 3 can be heat-insulated. ..

According to the leaf tobacco dryer 1 constructed as described above, first, the front door panel 26 is opened, a large number of leaf tobacco (fresh leaves) 35 are hung together with the hanger 36 in each drying chamber 3, and each door panel 26 is hung. When it is closed and the operation start button of the control unit 13 is pressed, the operation shifts to the main operation (mode) after the preliminary operation (mode), and the burner 11 is set based on the detected temperatures from the dry-bulb thermometer 33 and the wet-bulb thermometer 34. The combustion gas generated in the furnace 7 and the outside air introduced into the casing 4 from the intake port 8 by the blower 5 are heat-exchanged by the heat exchanger 6 to generate hot air. The generated hot air is blown into each pit P from the lower hot air outlet 10 and blown up from the rectifying plate 30 into the upper space of the drying chamber 3 to dry the leaf tobacco (fresh leaves) inside.

The preliminary operation (mode) by the control unit 13 is performed for a certain period of time (for example, 60 seconds). Specifically, when the operation start button is pressed, the burner 11 is turned on, and the outside air (combustion air) is sent into the furnace 7 from the attached blower and ignited after a certain period of time (for example, 15 seconds), and is synchronized. The outside air introduced into the casing 4 by the blower 5 operated circulates in the drying chamber 3 for a certain period of time (for example, 45 seconds), the burner 11 is temporarily turned off, and the temperature inside the drying chamber 3 becomes a dry-bulb thermometer. It is sampled and measured by 33 and a wet-bulb thermometer 34. Then, based on the sampled and measured operation start temperature, the main operation (mode) by the control unit 13 is started. By circulating in the drying chamber 3 for a certain period of time, the temperature and humidity conditions in the drying chamber 3 are stabilized, the detection accuracy of the operation start temperature is improved, and the drying failure of leaf tobacco can be prevented.

After the start of the main operation, the control unit 13 follows the preset drying program, and based on the temperature detected from the dry-bulb thermometer 33 and the wet-bulb thermometer 34, each of the initial drying stage, the middle drying stage, and the late drying stage. On / off control of the burner 11 and opening / closing control of the intake damper 16 are performed so that the temperature and humidity conditions maintain the target values. In general, the introduction of outside air and the discharge of moist air are actively carried out in the early stage of drying, the introduction and exhaust of outside air are gradually reduced in the middle stage of drying, and most of the air is circulated in the latter stage of drying.

In the leaf tobacco dryer 1 of the above embodiment, the floor panel 21 and the side panel 22 of the pit panel portion 18 use a heat insulating panel having a cross-sectional width of 42 m, and similarly, the side panel 23 (front panel 26, back surface) of the ground panel portion 19 is used. A heat insulating panel having a cross-sectional width of 42 mm may be used for the panel 27). By erection of the straightening vane 30 on the upper surface of the level base members 23, 23'with a cross-sectional height of 42 mm, the height of the lower space S1 between the floor panel 21 and the straightening vane 30 can be sufficiently secured, and the straightening vane 30 can be sufficiently secured. The flow velocity of the hot air below does not increase, the distribution balance of the hot air rising on the straightening vane 30 does not become imbalanced, the pressure loss does not increase due to the increase in the flow velocity, and the ventilation performance does not deteriorate, which affects drying. Can be prevented.

In the leaf tobacco dryer 1, as shown in FIG. 4, the rotation shaft 16A of the intake damper 16 is located near the ceiling of the casing 4 and is not closer to the circulation port 9 facing the intake port 8, but is the intake port 8 and the circulation port. Since it is arranged at a substantially intermediate position between the nines, resistance is likely to be applied to the circulation port 9, and both the intake characteristic and the exhaust characteristic can be improved. For example, when the intake damper 16 is opened 45 degrees and the outside air is introduced into the casing 4 from the intake port 8, the intake damper 16 at an inclined position of 45 degrees easily applies resistance to the circulation port 9 (indoor air circulating from). The exhaust characteristics can be improved in accordance with the improvement of the intake characteristics.

The leaf tobacco dryer 1 has a configuration in which a hot air generator 2 and a drying chamber 3 are installed in two rows of pits, but the present invention is not limited to this. A hot air generator and a drying chamber may be installed in one existing pit in the drying facility, or a new pit is provided next to the existing pit and a hot air generator and a drying chamber are installed in two rows of pits. You may.

Further, the foundation G in the above embodiment has a structure in which a convex central partition portion exists between the two rows of pits P and P as shown in FIG. 5, but is not limited to this. The central level partition member 23'may be supported by one or a plurality of columns by removing the central partition portion shown in FIG. 5 (including the case where the partition portion does not originally exist).

The present invention can be used as a method for constructing a leaf tobacco dryer and a leaf tobacco dryer for drying leaf tobacco.

1 Leaf tobacco dryer 2 Hot air generator 3 Drying room 4 Casing 5 Blower 6 Heat exchanger 7 Fireplace 8 Intake port 9 Circulation port 10 Hot air outlet 11 Burner 12 Exhaust duct 13 Control panel (control unit)
14 Exhaust port 15 Exhaust heat recovery and supply part 16 Intake damper 17 Air resistance plate 18 Pit panel part 19 Ground panel part 20 Ground base part 21 Bottom panel (bottom plate panel)
22,23 Side panel (side plate panel)
23A partition panel (side plate panel)
24 Top panel (top panel)
25 Observation window 26 Front door panel (side plate panel)
27 Back panel (side plate panel)
28, 28'Level base member 29 Joining metal fittings 30 Barrier plate 31 Supporting member 32 Suspended rail metal fittings 33 Dry-bulb thermometer 34 Wet-bulb thermometer 35 Leaf tobacco 36 Suspension tool 37 Aggregate 38 Roof support material G Foundation P Pit S1 Lower space S2 Leaf tobacco hanging space

Claims (3)

A hot air generator that heats the outside air taken into the casing from the intake port by a blower with a fireplace to generate high-temperature dry air, and a leaf tobacco are suspended, and the high-temperature dry air generated by the hot air generator is at the bottom. In a leaf tobacco dryer equipped with a drying chamber that is blown up from the space
The drying chamber is placed on a pit panel portion installed in an existing pit drilled in a foundation in a drying facility and placed on the upper surface of the foundation around the pit and joined to the upper part of the pit panel portion. It is composed of a ground base portion and a ground panel portion that is placed on the upper surface of the ground base portion and joined to the ground base portion, and the pit panel portion is composed of a plurality of heat insulating bottom plate panels and side plate panels. the ground panel unit, a heat-insulating a plurality of side plate panels and ceiling panels, the ground-based unit, as the peak Tsu preparative level base in a U-shape or a roughly rectangular shape in plan view around the It is composed of a plurality of base members arranged and having heat insulating properties, and the upper portion of the side plate panel of the pit panel portion and the lower portion of the side plate panel of the ground panel portion are integrally joined to each base member via a joint fitting, and the ground base is said. A straightening vane provided with a large number of through holes is erected between the upper surfaces of the portions via a support member.
Each base member of the above-ground base portion has a width dimension in the width direction of the pit wider than the width dimension of the side plate panel of the above-ground panel portion, and is a support member that supports the straightening vane with the side plate panel of the above-ground panel portion on the outside. Each is installed on the upper surface with the inside facing
Further, each base member of the above-ground base portion is a leaf tobacco dryer, wherein the thickness dimension of the pit in the depth direction is the same as the thickness dimension of the bottom plate panel of the pit panel portion. The exhaust heat recovery and supply unit is arranged in the casing in the vicinity of the exhaust port and the intake port, and the intake damper for opening and closing the intake port is arranged at a substantially intermediate position between the intake port and the circulation port. The leaf tobacco dryer according to claim 1, wherein an air volume adjusting plate for adjusting the opening area of the circulation port and adjusting the air volume circulating in the drying chamber is provided at the circulation port. It is equipped with a control unit that controls the burning of the burner to the furnace on and off, and the control unit operates the burner and the blower in the main operation based on the preliminary operation mode in which the burner and the blower are preliminarily operated for a certain period of time and the drying chamber temperature measured after the preparatory operation. In the preliminary operation mode, the control unit preliminarily operates the burner and the blower for a certain period of time to circulate the outside air taken into the casing in the drying chamber for a certain period of time, and stops the burner in the drying chamber. The temperature is sampled and measured, and when the sampled drying room temperature is the operation start temperature, the burner and blower are switched from the preliminary operation mode to the main operation mode, the main operation mode is started, and the drying program set in advance is followed. The leaf tobacco dryer according to claim 1 or 2, wherein the leaf tobacco dryer is configured to perform control.

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