CN210382558U

CN210382558U - Air heating parcher

Info

Publication number: CN210382558U
Application number: CN201920401175.1U
Authority: CN
Inventors: 曹江涛
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-03-27
Filing date: 2019-03-27
Publication date: 2020-04-24
Anticipated expiration: 2029-03-27

Abstract

The utility model relates to the field of baking and frying equipment, and provides an air heating baking and frying machine, which comprises a heating device, a hot air flow transmission channel, a hot air flow return channel and a baking and frying chamber; the air inlet of the heating device is connected with the hot air flow backflow channel, and the air outlet of the heating device is connected with the inlet of the hot air flow transmission channel; the outlet of the hot air flow transmission channel is downwards communicated with the baking and frying chamber, and the upper part of the baking and frying chamber is communicated with the hot air flow return channel; the hot air flow transmission channels are one group or a plurality of groups, the outlets are downwards communicated with the baking chamber from one side, two sides or the periphery of the baking chamber, and scrapers are arranged in the baking chamber. The utility model utilizes the circulating hot air flow to fully contact with the materials in the air, thereby achieving the purposes of efficiently, uniformly and rapidly heating the materials and reducing the temperature of the heat transfer medium; the surface of the interior of the baking and frying chamber is smooth, no dead angle exists, the gradient of the inner wall is large, the temperature of a heat transfer medium is low, and the materials cannot stay for a long time and are carbonized to generate black smoke; the utility model discloses novel structure, simple reasonable, high-efficient, environmental protection, application prospect are wide.

Description

Air heating parcher

Technical Field

The utility model relates to a parch equipment technical field, in particular to air heating parch machine for parch food, medicinal material, nut, grain and other materials.

Background

When the drum-type baking and frying machine bakes and fries materials, the heating drum heats the materials because the materials are in local point contact with the drum, the heating speed is slow, the heating is uneven, the temperature of the drum is high, the material is easy to be over-heated locally, the quality of finished products is influenced, even the guide rail is difficult to clean.

When the stirring type baking and frying machine is used for baking and frying materials, the pot bottom is heated, the materials are in local point contact with the pot bottom, the heating speed is low, the heating is not uniform, the temperature of the pot bottom is high, the materials can be over-heated locally easily to influence the quality of finished products, the pot can be burnt, and the pot bottom is difficult to clean.

When the material needs explosive rapid heating, the two modes can not be realized. The nuts are provided, and the fried nuts are crispy and delicious only by explosive rapid heating. In order to solve the problem of explosive rapid heating, sand or salt is generally used as a medium, the sand or salt is preheated to a certain temperature, then the material is put into the sand or salt, and the surface of the material is surrounded by the fine characteristics of the sand or salt particles to rapidly heat the material in an explosive manner. However, the method has a series of very troublesome problems of energy waste due to preheating, incomplete residue removal, incapability of meeting the requirements of health and environmental protection, need of replacing sand or salt regularly and the like. For sticky or matte materials, no sand or salt residue is removed at all. Because the surface of equipment in contact with the material is not smooth, the cleaning and maintenance are difficult, dust can stay in the dead angle, the temperature of the heat transfer medium is high, and the heat transfer medium is heated and carbonized for a long time to smoke black smoke.

For many years, materials such as food are baked and fried, a roller or a scraper type baking and frying machine with a guide rail on the inner wall is generally used, for example, Chinese utility model patent application publication No. CN 212174795U discloses a baking and frying machine, which belongs to a roller type, Chinese utility model patent application publication No. CN 213729795U discloses a material baking and frying machine, which belongs to a scraper type baking and frying machine, wherein the materials are all heating rollers or pan bottoms, and the materials have local point contact, slow heat transfer speed, uneven heating, high heat transfer medium temperature, dead corners, difficult cleaning of residues on internal guide rails or scrapers, easy local over-temperature carbonization, black smoke or even pan burning and are not environment-friendly.

SUMMERY OF THE UTILITY MODEL

The utility model discloses an it is slow just to overcome current parch equipment rate of heating, the heat transfer medium temperature is high, there is the dead angle, difficult clearance, can not make the material explosive rapid heating up, the inhomogeneous shortcoming of heating, utilize the circulation hot-air current to blow the material that the scraper blade had raised to in the air or directly blow material and the full surface of material fully contact, thereby reach the high efficiency, even, the rapid heating material makes its explosive heating up and the purpose that the heat transfer medium temperature is low, simultaneously with the surface of material contact smooth, the slope is big, there is not the dead angle, no dust stops, the pipe wall temperature is less than the material temperature, therefore avoid the emergence of material carbonization and emit black cigarette, the environmental protection, it is simpler and easier to clear up the maintenance.

The utility model adopts the following technical scheme:

an air heating baking and frying machine comprises a heating device, a hot air flow conveying channel, a hot air flow return channel and a baking and frying chamber;

the air inlet of the heating device is connected with the hot air flow backflow channel, and the air outlet of the heating device is connected with the inlet of the hot air flow conveying channel; the outlet of the hot air flow conveying channel is downwards communicated with the baking and frying chamber, and the upper part of the baking and frying chamber is communicated with the hot air flow return channel;

the hot air flow transmission channels are one group or a plurality of groups, and outlets are downwards communicated with the baking and frying chamber from one side, two sides or the periphery of the baking and frying chamber.

Furthermore, a scraping plate is arranged in the baking and frying chamber.

Furthermore, the air heating baking and frying machine also comprises a feeding device, a feeding control door and a discharging door; the feeding device is communicated with the baking and frying chamber, and the feeding control door is arranged between the feeding device and the baking and frying chamber; the discharge door is arranged at the discharge hole of the baking and frying chamber.

Further, the heating device comprises a fan, a heater and a diversion trench; the heater is arranged in the wind field of the fan, and the diversion trench is arranged on the periphery of the heater.

Furthermore, one or more groups of heating devices are arranged at one side, two sides, four sides or the middle above the baking and frying chamber, and the heating devices correspond to the hot air flow conveying channel.

Furthermore, the group of heating devices is arranged on one side above the baking and frying chamber, the outlet of the hot air flow conveying channel is downwards communicated with the baking and frying chamber from one side, and the hot air flow return channel is arranged above the other side of the baking and frying chamber.

Furthermore, a plurality of groups of heating devices are arranged on one side above the baking and frying chamber, the outlet of the hot air flow conveying channel is downwards communicated with the baking and frying chamber from one side, and the hot air flow return channel is arranged above the other side of the baking and frying chamber.

Furthermore, the two groups of heating devices are respectively arranged at two sides above the baking and frying chamber, the outlets of the hot air flow conveying channels are downwards communicated with the baking and frying chamber from two sides respectively, and the hot air flow return channels are arranged right above the baking and frying chamber.

Furthermore, the plurality of groups of heating devices are respectively arranged on two sides above the baking and frying chamber, the outlets of the hot air flow conveying channels are downwards communicated with the baking and frying chamber from two sides respectively, and the hot air flow return channels are arranged right above the baking and frying chamber.

Furthermore, the plurality of groups of heating devices are respectively arranged on the periphery above the baking and frying chamber, the outlets of the hot air flow conveying channels are downwards respectively communicated with the baking and frying chamber from the periphery, and the hot air flow return channels are arranged right above the baking and frying chamber.

Further, the air heating baking and frying machine comprises an inner cylinder and an outer cylinder; the heating device is arranged in the middle of the upper part of the inner cylinder, the interlayer between the outer cylinder and the inner cylinder forms the hot air flow transmission channel, the inner space of the inner cylinder forms the hot air flow return channel, and the bottom of the outer cylinder forms the baking and frying chamber.

Furthermore, the heating device is arranged in the center above the baking and frying chamber, the baking and frying chamber is arranged at the bottom, the bottom of the baking and frying chamber is in an arc shape, and the hot air flow conveying channels are arranged on two sides of the baking and frying chamber.

Furthermore, a movable guide plate can be arranged at the lower end of the hot air flow transmission channel close to the inner side, the downward length of the hot air flow transmission channel is extended, and when the scraper moves to the movable guide plate, the movable guide plate can deflect under the action of the scraper, so that the scraper is prevented from being blocked in movement.

Further, the scraper is longitudinally composed of one or more sections.

Furthermore, the scraper is obliquely arranged relative to the direction of the scraper transmission shaft, and when the scraper rotates in the positive direction and the reverse direction alternately, the materials move back and forth towards the discharge door and the reverse direction in the baking and frying chamber. And during discharging, the rotation direction of the scraper is controlled to enable the material to move towards the direction of the discharging door.

Furthermore, the scraper transmission shaft is composed of one or more sections, so that the scraper is convenient to disassemble.

Furthermore, a first temperature sensor is arranged on the surface of the heater, a second temperature sensor is arranged in the hot air flow conveying channel, and a fifth temperature sensor is arranged in the hot air flow conveying channel or below the bottom plate of the baking and frying chamber.

Furthermore, the discharge door is arranged on one side of the baking and frying chamber, and a discharge air door and a discharge blower are arranged on the opposite side of the discharge door to assist in discharging.

Furthermore, the feeding control door is a sliding door, and the discharging door and the discharging air door are rotating doors.

Furthermore, the air heating baking and frying machine is provided with a rotating device for driving the hot air flow conveying channel to rotate, a blow pipe which moves up and down is arranged near the outlet of the hot air flow conveying channel, and the angle and the position of the hot air flow entering the baking and frying chamber are dynamically changed in the working process.

Furthermore, a filter screen is arranged in the hot air flow backflow channel and used for filtering dust.

Furthermore, the top of the hot air flow return channel is provided with an exhaust pipe which is communicated with the atmosphere.

Furthermore, the cross section of the bottom of the baking and frying chamber is a circular arc.

Furthermore, the heat-insulating layer is arranged outside the pipeline through which the hot air flows, so that the energy consumption is reduced.

Furthermore, the heater is an electric heater, and the surface of the heating element is provided with a heat dissipation device, so that the contact area between the heater and the air flow is increased, and the surface temperature of the heating element is reduced.

Further, the fan is a centrifugal fan and is connected with a motor through a transmission shaft, and the motor is connected with a control system through a frequency converter; the rotating speed of the fan is controlled, so that the air flow speed, the pulse intensity and the period are controlled, the material fluctuates up and down in the frying chamber and is fully contacted with hot air flow, and the heat is quickly absorbed.

Furthermore, the air outlet of the heating device is connected with the inlet of the hot air flow conveying channel by a pipeline, and the air inlet of the heating device is connected with the hot air flow return channel by a pipeline.

A combined air heating baking and frying machine comprises 2 or more air heating baking and frying machines which are arranged side by side, wherein baking and frying chambers are communicated into a whole; one end of the baking and frying chamber is provided with a feeding device, and the other end of the baking and frying chamber is provided with a discharge door.

The utility model has the advantages that: the circulating hot air flow is utilized to blow the material raised by the scraper or directly blow the material to fully contact with the whole surface of the material, so that the material is efficiently, uniformly and rapidly heated to be heated explosively; the surface of the interior of the baking and frying chamber is smooth, no dead angle exists, the gradient of the inner wall is large, the temperature of a heat transfer medium is low, and the materials cannot generate black smoke due to long-time stay, heating and carbonization; the whole surface of the material is contacted with the air flow, the heat absorption is fast, the temperature rise is fast, and the quality of the finished product cannot be influenced by local over-temperature. The utility model discloses novel structure, simple reasonable, high-efficient heating, heat transfer medium temperature are low, the environmental protection, have wide application prospect.

Drawings

FIG. 1a is a schematic sectional view (A-A sectional view) of an air heating roaster according to embodiment 1.

Fig. 1b is a schematic sectional view (longitudinal sectional view) of an air heating roasting machine according to embodiment 1.

Fig. 2 is a schematic sectional view of an air heating roasting machine according to embodiment 2.

FIG. 3 is a schematic sectional view of the air heating roaster having a plurality of heating units according to example 3.

Fig. 4a is a schematic sectional view (transverse sectional view) of an air heating roasting machine according to embodiment 4.

Figure 4B shows a cross-sectional view B-B of figure 4 a.

Fig. 5a is a schematic sectional view (a transverse sectional view) of an air heating roaster according to embodiment 5.

Figure 5b shows a cross-sectional view C-C in figure 5 a.

Wherein: 1-a heat preservation shell; 2-a diversion trench; 3-a first temperature sensor; 4-a fan drive shaft; 5, a motor; 6-a fan; 7-a heater; 8-a second temperature sensor; 9-hot air flow delivery channel; 10-baking and frying room; 11-a scraper; 12-hot gas flow back to the flow channel; 13-a third temperature sensor; 14-a fourth temperature sensor; 15-an exhaust pipe; 16-a filter screen; 17-a fan air inlet; 18-a fifth temperature sensor; 19-a feeding device; 20-a feeding control gate; 21-a scraper transmission shaft; 22-a discharge damper; 23-a discharge blower; 24-a discharge device; 25-discharge door.

Detailed Description

Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that technical features or combinations of technical features described in the following embodiments should not be considered as being isolated, and they may be combined with each other to achieve better technical effects.

Example 1

As shown in fig. 1a and fig. 1b, an air heating baking and frying machine according to an embodiment of the present invention includes a feeding device 19, a feeding control door 20, a hot air flow conveying channel 9, a baking and frying chamber 10, a scraping plate 11, a hot air flow return channel 12, a filter screen 16, a discharge door 25, a discharge device 24, an exhaust pipe 15, a heating device, and a heat insulation housing 1;

the heating device comprises a fan 6, a heater 7 and a diversion trench 2; the air inlet of the fan 6 is connected with the hot air flow return channel 12, the heater 7 is arranged in the air field of the fan 6, the diversion trench 2 is arranged on the periphery of the heater 7, and the air outlet of the fan 6 is connected with the inlet of the hot air flow transmission channel 9;

the hot air flow transmission channel 9 is arranged above two sides of the baking and frying chamber 10, the outlet of the hot air flow transmission channel is downwards communicated with the baking and frying chamber 10, and the hot air flow return channel 12 is arranged right above the baking and frying chamber 10; a group of heating devices are respectively arranged at two sides above the hot air conveying channel, and the air outlets of the fans 6 are respectively connected with the inlets of the hot air conveying channels 9 at two sides;

the filter screen 16 is arranged in the hot air flow return channel 12, and the hot air flow return channel 12 is communicated with the atmosphere through the exhaust pipe 15; the feeding device 19 is connected with the baking and frying chamber 10, the feeding control door 20 is arranged between the feeding device and the baking and frying chamber 10, the scraper 11 is arranged in the baking and frying chamber 10, the scraper 11 is driven by a scraper transmission shaft 21, and the baking and frying chamber 10 is connected with the discharging device 24 through the discharging door 25.

On the basis of the embodiment 1, a plurality of optimizations can be made:

as shown in fig. 1a and fig. 1b, the upper part of the horizontal section of the parching chamber 10 is square, the lower part is partially cylindrical, the surfaces of the heaters 7 at two sides are respectively provided with a first temperature sensor 3 and a fourth temperature sensor 14, the hot air flow conveying channels 9 at two sides are respectively provided with a second temperature sensor 8 and a third temperature sensor 13, and the hot air flow conveying channel 12 is internally provided with a fifth temperature sensor 18 which is connected with a control system; the fan 6 is a centrifugal fan, the motor 5 drives the fan 6 to rotate through the fan transmission shaft 4, the motor 5 is controlled by a frequency converter, the heater 7 is arranged around the fan 6, the heater 7 is an electric heater provided with a radiator, the diversion trench 2 is arranged around the heater 7, and an air outlet of the diversion trench 2 is connected with an inlet of the hot air flow transmission channel 9; the scraper 11 is longitudinally and obliquely arranged relative to the scraper transmission shaft 21 and consists of a plurality of sections; the pipeline through which the hot air flows is provided with a heat preservation system; each part is provided with a support frame.

Further preferably, an outlet air door 22 and an outlet air blower 23 are arranged at the opposite side of the outlet door 25 to assist in discharging.

Further preferably, a movable deflector may be disposed at a lower end of the hot air flow transmission channel 9 close to the inner side plate, and a downward length of the hot air flow transmission channel 9 is extended, so that when the scraper 11 moves to the movable deflector, the movable deflector can deflect under the action of the scraper 11, thereby avoiding blocking the movement of the scraper 11.

Preferably, a rotating device is arranged to drive the hot air flow conveying channel 9 to rotate, a blow pipe which moves up and down is arranged near the outlet of the hot air flow conveying channel 9, and the angle and the position of hot air flow entering the baking and frying chamber 10 are dynamically changed in the working process.

Preferably, the feeding control door 20 is a sliding door, and the discharging door 25 and the discharging damper 22 are revolving doors.

Further preferably, the scraper transmission shaft 21 is composed of multiple sections, so that the scraper transmission shaft is convenient to disassemble.

Further preferably, the upper side cover plate of the hot air flow return channel 12 is movable, so that the scraper 11 can be conveniently installed and cleaned.

Further preferably, the discharging side is provided with a movable cover plate, so that the scraper 11 can be conveniently installed and cleaned.

Further preferably, the heating device is independently arranged, the air outlet of the heating device is connected with the hot air flow transmission channel 9 through a pipeline, and the air inlet of the heating device is connected with the hot air flow return channel 12 through a pipeline.

Example 2

Fig. 2 is another embodiment, which is different from embodiment 1 (fig. 1a and 1b) in that: fig. 1a and 1b include two sets of the heating devices and two sets of the hot air flow transmission channels 9, which are arranged above two sides of the baking and frying chamber 10, and the hot air flow return channels 12 are arranged right above the baking and frying chamber 10. In fig. 2, the heating device and the hot air flow transmission channel 9 are arranged on the upper part of only one side, and the hot air flow return channel 12 is arranged on the upper part of the other side of the baking and frying chamber 10.

Example 3

Fig. 3 shows another embodiment, which is different from embodiment 1 (fig. 1a and 1b) in that: fig. 1a and 1b include two groups of heating devices, which are arranged above two sides of the baking and frying chamber 10. And a plurality of groups of the heating devices are respectively arranged above the two sides of the figure 3.

Example 4

Fig. 4a and 4b show another embodiment, which is different from embodiment 1 (fig. 1a and 1b) in that: fig. 1a and 1b include two sets of the heating devices and two sets of the hot air flow transmission channels 9, which are arranged above two sides; the upper part of the horizontal section of the air heating baking machine is square, while the heating devices in figure 4a and figure 4b are only one group and are arranged above the center, the air heating baking machine comprises an inner cylinder and an outer cylinder, the horizontal section is circular, the outer cylinder is arranged outside, an interlayer between the inner cylinder and the outer cylinder is used as the hot air flow transmission channel 9, and the bottom is the baking chamber 10.

Example 5

Fig. 5a and 5b show another embodiment, which is different from embodiment 1 (fig. 1a and 1b) in that: fig. 1a and 1b include two sets of the heating devices and two sets of the hot air flow transmission channels 9, which are arranged above two sides, and the hot air flow transmission channels 9 are respectively connected with the heating devices; in fig. 5a and 5b, only one group of heating devices is arranged above the center and communicated with two groups of hot air flow transmission channels 9 arranged at two sides.

The utility model discloses other deformations still, if the outside of hot-blast conveying pipe 9 outside and the outside of parch room 10 are not in the coplanar, the outside board of hot-blast conveying pipe 9 moves outwards, is connected through the outside of swash plate with parch room 10.

The utility model discloses still other deformations, if independent setting heating device, its air outlet and hot gas flow transfer passage 9's entry are with the pipe connection, and its income wind gap and hot gas flow return passage 12 are with the pipe connection.

The utility model also has other deformation, such as arranging the fifth temperature sensor 18 under the bottom plate of the baking and frying chamber 10.

The utility model discloses other still warp, if many sets of air heating parch machine parallelly connected uses, one set of feeding equipment of sharing constitutes the parch system of continuous feeding under control system's control. Meanwhile, the control system also controls the heating power distribution of each set of system in real time, so that the total power is reduced.

The embodiment of the utility model provides a theory of operation as follows:

when the materials are baked, the feeding control door 20 is opened, the materials slide to the bottom of the baking and frying chamber 10 under the action of gravity, then the feeding control door 20 is closed, the fan 6 is started to operate, hot air flow is blown downwards to the baking and frying chamber 10 from the hot air conveying pipeline 9, meanwhile, the materials are raised by the rotating scraper blade 11, and a part of the materials continuously roll in the air to exchange the upper position and the lower position and are completely contacted with hot air for baking and frying. On the other hand, the hot air flow is directly blown to the bottom material to be baked, part of the material flies into the air to be baked, the hot air flow transfers heat to the material and then cools the material to enter the hot air flow backflow channel 12, the filter screen 16 blocks the lifted material, and the lifted material is prevented from entering the heating device. The inclined scrapers 11 rotate in opposite directions alternately to move the material longitudinally back and forth. The fan 6 sucks the hot air having a low temperature in the hot air flow path 12, and blows the hot air to the electric heater 7 with a radiator to be heated again. The heated hot air flow is gathered to the air outlet of the fan 6 by the peripheral diversion trench 2 and circularly enters the baking chamber 10 again through the hot air conveying pipeline 9 to continuously bake and fry the materials. The frequency converter controls the rotating speed of the fan 6, thereby controlling the speed of hot air flow, enabling the material to fluctuate up and down and to be fully contacted with the hot air, and being beneficial to quickly heating the material. The control system controls the surface temperature of the electric heater 7 according to the signals of the first temperature sensor 3 and the fourth temperature sensor 14, controls the temperature of hot air flow according to the signals of the second temperature sensor 8 and the third temperature sensor 13, and judges the baking and frying progress according to the fifth temperature sensor 18. The moisture is discharged through the exhaust pipe 15. After the material is baked and fried, the fan 6 stops running, the discharge door 25 is opened, the rotation direction of the scraper blade 11 is controlled, the material moves towards the discharge door 25, the material enters the discharging device 24 under the action of gravity after reaching the outlet of the material, then the feeding control door 20 is opened again, and after the material enters the baking and frying chamber 10 again, the fan 6 is started to run, and the next round of baking and frying is started. So as to reciprocate.

While several embodiments of the present invention have been presented herein, it will be appreciated by those skilled in the art that changes can be made to the embodiments herein without departing from the spirit of the invention. The above-described embodiments are merely exemplary and should not be taken as limiting the scope of the invention.

Claims

1. An air heating baking and frying machine is characterized by comprising a heating device, a hot air flow conveying channel, a hot air flow return channel and a baking and frying chamber;

the air inlet of the heating device is connected with the hot air flow backflow channel, and the air outlet of the heating device is connected with the inlet of the hot air flow conveying channel; the upper part of the baking and frying chamber is communicated with the hot air flow return channel; a filter screen is arranged in the hot gas flow return channel;

2. The air heating roasting machine of claim 1, wherein the air heating roasting machine further comprises a feeding device, a feeding control door and a discharging door; the feeding device is communicated with the baking and frying chamber through the feeding control door; the discharge door is arranged at the discharge hole of the baking and frying chamber.

3. The air heating roaster of claim 1, wherein the heating device comprises a fan, a heater, and a baffle trough; the heater is arranged in the wind field of the fan, and the diversion trench is arranged on the periphery of the heater.

4. The air heating roaster of claim 3, wherein one or more sets of the heating devices are disposed at one side, two sides, four sides, or the middle above the roasting chamber, and the heating devices are disposed corresponding to the hot air flow conveying passage.

5. An air heating roasting machine as claimed in any one of claims 1 to 4 wherein said roasting chamber is provided with a scraper, said scraper being formed of one or more segments in a longitudinal direction, said scraper being disposed obliquely with respect to a direction of a scraper drive shaft, said scraper drive shaft being formed of one or more segments.

6. An air heating cooking machine as claimed in claim 3, wherein a first temperature sensor is provided on the heater surface, a second temperature sensor is provided in the hot air flow path, and a fifth temperature sensor is provided in the hot air flow path or below the floor of the cooking chamber.

7. The air heating fryer of claim 1, wherein said air heating fryer comprises an inner drum and an outer drum; the heating device is arranged in the middle of the upper part of the inner cylinder, the interlayer between the outer cylinder and the inner cylinder forms the hot air flow transmission channel, the inner space of the inner cylinder forms the hot air flow return channel, and the bottom of the outer cylinder forms the baking and frying chamber.

8. An air heating roaster as set forth in claim 2 wherein the discharge gate is disposed at a side of the roasting chamber, and a discharge damper and a discharge blower are disposed at an opposite side of the discharge gate.

9. An air heating fryer according to claim 1, wherein said air heating fryer is provided with rotating means for driving said hot air flow conveying path to rotate, and wherein a blow pipe movable up and down is provided adjacent to the exit of said hot air flow conveying path to dynamically change the angle and position of the hot air flow entering said cooking chamber during operation.

10. The air heating roaster of claim 1, wherein a movable deflector is provided at a lower end of the inner side plate of the hot air flow transfer passage to extend a downward length of the hot air flow transfer passage.