阅读说明：本技术 一种带烘干功能的烤箱 (Oven with drying function ) 是由 蒋圣伟 卜玲娟 于 2019-10-30 设计创作，主要内容包括：本发明涉及一种带烘干功能的烤箱,包括内胆,内胆的顶板上开设有排气口,排气口与具排气风机的排气通道相流体连通,内胆的下部设置有具第一进风口和第一出风口的热风挡板,热风挡板与内胆的底板围成下热风室,热风室中设置有离心扇叶,离心扇叶的外周围设有下加热管,热风挡板的第一进风口上罩设有具第二风口和第二出风口的气流罩,且该气流罩与热风挡板围成的分流空间中安装有轴流扇叶,该轴流扇叶与上述离心扇叶同轴设置。本发明在内胆中形成上下方向的热风循环,提高对内胆中水汽的处理效率,进而使得本发明中的烤箱在烹饪水分含量较多能获得较好的烘烤效果,同时由于本发明中的烤箱能快速排放内胆中的水汽,使得该烤箱同时适用于烘干食物。(The invention relates to an oven with a drying function, which comprises an inner container, wherein an exhaust port is formed in a top plate of the inner container, the exhaust port is in fluid communication with an exhaust channel with an exhaust fan, a hot air baffle with a first air inlet and a first air outlet is arranged at the lower part of the inner container, a lower hot air chamber is enclosed by the hot air baffle and a bottom plate of the inner container, a centrifugal fan blade is arranged in the hot air chamber, a lower heating pipe is arranged around the centrifugal fan blade, an airflow cover with a second air inlet and a second air outlet is arranged on an upper cover of the first air inlet of the hot air baffle, an axial flow fan blade is arranged in a flow dividing space enclosed by the airflow cover and the hot air baffle, and the axial flow fan blade. The hot air circulation in the vertical direction is formed in the inner container, the treatment efficiency of water vapor in the inner container is improved, the oven can obtain a good baking effect when the cooking water content is high, and meanwhile, the oven can quickly discharge the water vapor in the inner container, so that the oven is suitable for baking food.)

1. An oven with a drying function comprises an inner container (1), and is characterized in that an exhaust port (11) is formed in a top plate of the inner container (1), the exhaust port (11) is in fluid communication with an exhaust passage (80) with an exhaust fan (9), a hot air baffle (2) is arranged at the lower part of the inner container (1), a first air inlet (21) is formed in the center of the hot air baffle (2), a first air outlet (22) is formed in the side edge of the hot air baffle (2), a lower hot air chamber (20) is formed by the hot air baffle (2) and a bottom plate of the inner container (1), a centrifugal fan blade (31) is arranged in the lower hot air chamber (20), a lower heating pipe (43) is arranged on the outer periphery of the centrifugal fan blade (31),

an airflow cover (5) is arranged on the upper cover of the first air inlet (21) of the hot air baffle (2), a second air inlet (51) and a second air outlet (52) are respectively formed in the airflow cover (5), an axial flow fan blade (32) is installed in a flow dividing space (50) enclosed by the airflow cover (5) and the hot air baffle (2), and the axial flow fan blade (32) and the centrifugal fan blade (31) are coaxially arranged.

2. The oven according to claim 1, wherein the number of the first air outlets (22) is at least two, and the first air inlets (21) are arranged along the circumference of the hot air baffle (2), the top of the airflow hood (5) is in a plane shape to form an oil blocking plane (500), an oil blocking convex rib (53) is arranged on the oil blocking plane (500) in an upward protruding manner, the second air outlets (52) are arranged on the vertical side wall of the oil blocking convex rib (53), the axial flow fan blades (32) are arranged below the oil blocking plane (500), and the second air inlets (51) are respectively arranged on the side wall of the airflow hood (5).

3. The oven according to claim 2, characterized in that said second outlet opening (52) and said outlet opening (11) are arranged opposite one another.

4. The oven according to claim 3, characterized in that it further comprises a baking pan (6), the bottom wall of the baking pan (6) being provided with ventilation holes (61).

5. The oven according to claim 2, characterized in that the oil blocking rib (53) is formed by the top wall of the airflow hood (5) rising upwards, and the oil blocking rib (53) is shaped like a square bar, and the second air outlets (52) are respectively and uniformly distributed on the two side walls along the length direction.

6. The oven according to claim 5, characterized in that the oil blocking ribs (53) are at least two parallel ribs, each oil blocking rib (53) is provided at intervals, an oil receiving groove (54) is provided between adjacent oil blocking ribs (53), the oil receiving groove (54) extends along the length direction of the oil blocking ribs (53), and the outer surface of each oil blocking rib (53) is smooth.

7. The oven according to claim 1, wherein the cross section of the airflow hood (5) is square, and the airflow hood has at least one pair of side walls which are oppositely arranged and inclined from top to bottom to outside, the side walls are respectively provided with the second air inlets (51), and the opening of each second air inlet (51) extends upwards along the vertical direction of the wall surface thereof to form an oil blocking peripheral wall (511).

8. A toaster according to claim 7, wherein the air flow hood (5) is removably connected to the hot air baffle (2).

9. The oven according to claim 1, characterized in that a deflector (221) extends downwards from one side edge of each first air outlet (22).

10. The oven according to claim 1, characterized in that the top wall of the inner container (1) is fitted with an upper heating tube (41) and the back plate is fitted with a back heating tube (42).

Technical Field

The invention relates to the field of ovens, in particular to an oven with a drying function.

Background

An oven is a common cooking device, which uses a built-in heating device to bake and roast food. The rear side of the inner container of the oven is generally provided with a hot air baffle with an air inlet and an air outlet, the hot air baffle and the back plate of the inner container enclose a hot air chamber, an air heater is arranged in the hot air chamber, and the outer periphery of the air heater is provided with a back heating pipe. When the hot air blower rotates, air in the inner container is sucked into the hot air chamber through the air inlet on the hot air baffle, the air sucked into the hot air chamber is heated into hot air and then flows back into the inner container through the air outlet on the hot air baffle, and food is heated through the hot air flowing back into the inner container. Because hot-blast baffle and air heater all set up at the back of inner bag for food can't be discharged the cavity outside by the steam that evaporates out rapidly, makes current oven toast the effect relatively poor when toasting the food that contains more moisture. The food dryer can be used for making dried fruit, dried meat, flowers and plants, etc., and is internally provided with a heating device for drying food, wherein the drying temperature is generally 35-70 ℃. The arrangement of the hot air baffle plate and the hot air fan of the existing oven can not quickly discharge water vapor evaporated from food, so that the existing oven can not be directly used for drying the food.

Disclosure of Invention

The first technical problem to be solved by the invention is to provide an oven with a drying function, which can quickly discharge water vapor in an inner container, aiming at the prior art.

The second technical problem to be solved by the present invention is to provide an oven with a drying function that can avoid the influence of oil stains.

The technical scheme adopted by the invention for solving at least one technical problem is as follows: the exhaust fan is characterized in that an exhaust port is formed in a top plate of the inner container and is in fluid communication with an exhaust channel with an exhaust fan, a hot air baffle is arranged at the lower part of the inner container, a first air inlet is formed in the center of the hot air baffle, a first air outlet is formed in the side edge of the hot air baffle, a lower hot air chamber is formed by the hot air baffle and a bottom plate of the inner container in a surrounding mode, a centrifugal fan blade is arranged in the lower hot air chamber, a lower heating pipe is arranged on the outer periphery of the centrifugal fan blade, an airflow cover is arranged on the first air inlet of the hot air baffle in a covering mode, a second air inlet and a second air outlet are formed in the airflow cover respectively, an axial flow fan blade is installed in a flow dividing space formed.

Furthermore, the first air outlets are at least two and are circumferentially arranged along the periphery of the hot air baffle by taking the first air inlet as a center, the center of the top of the air flow cover is planar to form an oil blocking plane, an oil blocking convex rib is arranged on the oil blocking plane in an upward protruding mode, a second air outlet communicated with the inside of the air flow cover is formed in the vertical side wall of the oil blocking convex rib, the axial flow fan blades are arranged below the oil blocking plane, and the second air inlets are formed in the side wall of the air flow cover respectively. Therefore, the hot air circulation in the vertical direction can be better formed in the inner container, the influence of oil drops on the air outlet of the second air outlet cannot be avoided, the air outlet of the second air outlet can better move from bottom to top, the upper and lower circulation of air flow in the inner container can be better realized, and meanwhile, the downward movement of oil smoke in the drying process is better blocked.

Furthermore, the second air outlet and the air outlet are arranged oppositely up and down. The second air outlet forms air flow from bottom to top under the action of the axial flow fan blades, and the exhaust port forms negative pressure suction under the action of the exhaust fan, so that moisture and/or oil smoke can be better discharged through the exhaust port.

Further, the baking pan also comprises a baking pan, and vent holes are distributed on the bottom wall of the baking pan. In the drying process, hot air flows from bottom to top through the vent holes to take away moisture in food, so that the food on the baking pan can be dried better.

For can avoid oil to drip to get into down hot-blast room through the second air outlet better, keep off oily protruding muscle and form by the roof uplift up of air current cover, and this appearance that keeps off oily protruding muscle is the square strip form, and the equipartition has above-mentioned second air outlet respectively on its length direction's the both sides lateral wall.

For can collect the oil that drips to the air current cover better and drip, keep off oily protruding muscle and have two of parallel arrangement at least, each keeps off oily protruding muscle interval and all establishes, and is provided with between the adjacent protruding muscle of fender oil and connects the oil groove, should connect the oil groove to extend along the length direction who keeps off oily protruding muscle, and the surface that each keeps off oily protruding muscle all is slick and sly form.

In order to make the air current in the inner bag can get into the reposition of redundant personnel space better, the cross section of air current cover is personally submitted squarely, and it has a pair of relative setting from top to bottom outside slope's lateral wall at least, has seted up above-mentioned second air intake on this lateral wall respectively, and the mouth of each second air intake is followed respectively and is upwards extended along the vertical direction circumference rather than the place wall and form and keep off the oil perisporium, can avoid toasting the in-process oil droplet and drip into in the second air intake through keeping off the oil perisporium.

For the convenience of daily maintenance of users, the airflow cover is detachably connected with the hot air baffle. When the airflow cover is cleaned, the airflow cover is only required to be detached from the hot air baffle and directly washed by hand or put into a washing device such as a dish washer and the like for washing.

Furthermore, a flow deflector extends downwards from the edge of one side of each first air outlet. The flow deflector can guide the hot air flow at the first air outlet, so that the hot air flow enters the inner container from the first air outlet and moves upwards.

Further, install the heating pipe on the roof of inner bag, install back of the body heating pipe on the backplate to can heat the air current in the inner bag, further improve drying efficiency or toast efficiency.

Compared with the prior art, the invention has the advantages that: the top plate of the inner container is provided with an exhaust port which is in fluid communication with an exhaust channel with an exhaust fan, the lower part of the inner container is provided with a hot air baffle plate with a first air inlet and a first air outlet, the hot air baffle plate and the bottom plate of the inner container enclose a lower hot air chamber, a centrifugal fan blade is arranged in the lower hot air chamber, the outer periphery of the centrifugal fan blade is provided with a lower heating pipe, in addition, the hot air baffle plate is provided with an airflow cover with a second air inlet and a second air inlet, and an axial flow fan blade is arranged in a shunting space enclosed by the airflow cover and the hot air baffle plate.

Thus, the air flow in the inner container enters the lower hot air chamber from top to bottom through the first air inlet on the hot air baffle, the air flow entering the lower hot air chamber is heated and then returns to the inner container through the first air outlet under the action of the centrifugal force of the centrifugal fan blade, and rises upwards under the action of the negative pressure of the air outlet, so that the air flow in the middle part is formed in the inner container and enters the lower hot air chamber downwards, then enters the lower hot air chamber from the lower hot air chamber along the air flow movement mode of the up-and-down circulation of the inner cavity periphery of the inner container, meanwhile, under the action of the axial flow fan blade (the cooperation of the axial flow fan blade and the centrifugal fan blade), the air flow in the inner container can more fully enter the diversion space and enter the lower hot air chamber through the first air inlet, because the suction force of the centrifugal fan blade is larger than that of the axial flow fan blade under the same rotating speed, most of the air entering the diversion space enters, the upward flowing air flow can not only increase the mobility of the air flow in the middle of the inner container, and further promote the mobility of the air flow in the whole inner container, so that the air flow circulating up and down is better formed in the inner container, meanwhile, the upward rising air flow can also block the downward movement of the oil smoke during baking, and then the oil smoke can be better discharged through the exhaust port directly. In addition, the arrangement of the airflow cover can also prevent oil drops generated in the baking process from polluting the lower hot air chamber, the hot air blower in the lower hot air chamber and the lower heating pipe.

In conclusion, the hot air circulation in the vertical direction is formed in the inner container, the discharge direction of water vapor is exactly the same as the hot air circulation direction, so that the water vapor generated in the inner container can quickly enter the exhaust channel through the exhaust port and be discharged outside, the treatment efficiency of the water vapor in the inner container is improved, the oven in the invention can obtain a better baking effect when the cooking water content is higher, and meanwhile, the oven can quickly discharge the water vapor in the inner container, so that the oven is simultaneously suitable for drying food, such as making dried fruit, dried meat, scented tea and the like.

Drawings

FIG. 1 is a schematic structural view of an oven according to an embodiment of the present invention;

FIG. 2 is a schematic view of the structure of FIG. 1 in another direction;

FIG. 3 is a schematic view of the air flow circulation inside the oven liner according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a hot air baffle according to an embodiment of the present invention;

FIG. 5 is a schematic view of a configuration of a baking pan according to an embodiment of the present invention;

FIG. 6 is a schematic view of an embodiment of the present invention;

FIG. 7 is a cross-sectional view of an airflow shroud in an embodiment of the invention;

FIG. 8 is an enlarged view of portion A of FIG. 7;

fig. 9 is an enlarged view of a portion B in fig. 7.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.

As shown in fig. 1 to 9, an oven with a drying function includes an inner container 1, an upper heating pipe 41 is installed on an inner top surface of the inner container 1, a lower heating pipe 43 is installed on an inner bottom surface, and a back heating pipe 42 is installed on an inner surface of a back plate. An air outlet 11 is formed in the center of a top plate of the inner container 1, an upper mounting plate 7 is arranged above the inner container 1, an air guide cover 8 is arranged on the upper mounting plate 7 in a covering mode, an air exhaust channel 80 is formed by the air guide cover 8 and the upper mounting plate 7 in a surrounding mode, an air inlet end of the air exhaust channel 80 is provided with an air exhaust fan 9, and the air exhaust fan 9 is a cross-flow fan in the embodiment. An exhaust hole 71 is opened in the upper mounting plate 7, the exhaust hole 71 is located in the exhaust passage 80, and the exhaust hole 71 is communicated with the exhaust port 11 through an exhaust pipe 10.

Further, the lower part of the inner container 1 is provided with a hot air baffle 2 having a first air inlet 21 and a first air outlet 22, the hot air baffle 2 and the bottom plate of the inner container 1 enclose a lower hot air chamber 20, a centrifugal fan blade 31 is arranged in the lower hot air chamber 20, the bottom of the inner container 1 is provided with a driving motor 3, and an output shaft 30 of the driving motor 3 vertically extends upwards and penetrates through the bottom of the inner container 1 to be connected with a central hole of the centrifugal fan blade 31. The lower heating pipe 43 is annularly shaped and disposed around the periphery of the centrifugal fan blade 31. As shown in fig. 3, the oven can form a hot air circulation in the up-down direction in the inner container 1, so that the water vapor generated in the inner container 1 can rapidly enter the exhaust channel 80 through the exhaust port 11 and be discharged outside, the exhaust speed of the water vapor in the inner container 1 is increased, and the oven of the invention can obtain a good baking effect when cooking food with a large water content. In addition, the baking pan 6 is also included, and the bottom wall of the baking pan 6 is provided with vent holes 61. In the drying process, hot air flows from bottom to top through the vent holes 61 to take away moisture in food, so that the food on the baking pans 6 can be dried better, and particularly when a plurality of baking pans 6 are arranged in the liner 1, an upper air flow and a lower air flow are formed among the baking pans 6 through the vent holes 61, so that the drying efficiency is improved. When the oven is in a baking mode, a common baking tray can be used for baking, and tinfoil paper can also be laid on the baking tray 6, so that liquid substances generated in the food baking process can be prevented from dripping to the lower part of the inner container 1.

Further, as shown in fig. 4, the first air inlet 21 is disposed at the center of the hot air baffle 2, and the number of the first air outlets 22 is at least two and is disposed along the circumference of the hot air baffle 2 with the first air inlet 21 as the center, in this embodiment, the number of the first air outlets 22 is 10, so that the hot air in the hot air chamber 20 can better rise to the periphery of the liner 1 through the first air outlets 22 under the action of the centrifugal force of the centrifugal fan 31. Preferably, a flow deflector 221 extends downwards from one side edge of each first air outlet 22. The flow deflector 221 can guide the hot air flow at the first air outlet 22, so that the hot air flow enters the liner 1 from the first air outlet 22 and moves upward.

In order to prevent oil droplets generated during the baking process from contaminating the hot air chamber 20 and the centrifugal fan blades 31 and the lower heating pipes 43 in the hot air chamber 20, the first air inlet 21 of the hot air baffle 2 is covered with an air flow cover 5, as shown in fig. 5, the air flow cover 5 is respectively provided with a second air inlet 51 and a second air outlet 52, and the axial fan blades 32 are installed in a flow dividing space 50 enclosed by the air flow cover 5 and the hot air baffle 2, the axial fan blades 32 are coaxially arranged with the centrifugal fan blades 31, i.e. the output shaft 30 of the driving motor 3 penetrates through the central hole of the centrifugal fan blades 31 and then continues to extend upwards and penetrate through the central hole of the axial fan blades 32, i.e. the same motor can drive the centrifugal fan blades 31 and the axial fan blades 32 simultaneously, and the centrifugal fan blades 31 and the axial. Thus, the air flow in the inner container 1 enters the lower hot air chamber 20 from top to bottom through the first air inlet 21 on the hot air baffle 2, the air flow entering the lower hot air chamber 20 is heated and then returns to the inner container 1 through the first air outlet 22 under the action of the centrifugal force of the centrifugal fan blade 31, and rises upwards under the action of the negative pressure of the air outlet 11, so that the air flow in the middle part formed in the inner container 1 enters the lower hot air chamber 20 downwards, then enters the inner container 1 along the air flow movement mode of the up-and-down circulation along the inner cavity periphery of the inner container 1 from the lower hot air chamber 20, and meanwhile, under the action of the axial flow fan blade 32 (the cooperation of the axial flow fan blade 32 and the centrifugal fan blade 31), the air flow in the inner container 1 can enter the diversion space 50 more fully and enters the lower hot air chamber 20 through the first air inlet 21, and most of the air entering the diversion space 50 enters the lower hot air chamber 20 downwards to be heated, the residual air flows upwards through the second air outlet 52 on the air flow cover 5 under the action of the axial flow fan blade 32, the upward flowing air flow can not only increase the fluidity of the air flow in the middle of the inner container 1, and further promote the fluidity of the air flow in the whole inner container 1, so that the air flow circulating up and down can be better formed in the inner container 1, meanwhile, the upward rising air flow can also block the downward movement of the oil smoke during baking, and then the oil smoke can be better discharged out through the air outlet 11.

The cross section of the airflow cover 5 is square, an oil blocking plane 500 is formed on the top surface of the airflow cover 5, the top wall of the airflow cover 5 is raised upwards to form an oil blocking convex rib 53, the oil blocking convex rib 53 is square and strip-shaped, and the second air outlets 52 are uniformly distributed on the side walls of the two sides along the length direction of the oil blocking convex rib. The oil blocking ribs 53 at least have two (four in this embodiment) arranged in parallel, each oil blocking rib 53 is arranged at an interval, an oil receiving groove 54 is arranged between the adjacent oil blocking ribs 53, the oil receiving groove 54 extends along the length direction of the oil blocking ribs 53, and the outer surface of each oil blocking rib 53 is smooth, so that oil drops dripping on the airflow hood 5 can be better collected. Further, the lowest part of each second air outlet 52 is at least 5mm higher than the corresponding oil receiving groove 54, so that oil drops collected in the oil receiving groove 54 can be prevented from entering the diversion space 50 through the second air outlet 52. In this embodiment, the left and right side walls of the airflow hood 5 are inclined outward from top to bottom, the front and rear side walls are vertical walls extending vertically, the left and right side walls are respectively provided with the second air inlets 51 along the front-rear direction, the opening of each second air inlet 51 extends upward along the circumferential direction perpendicular to the wall surface where the second air inlet is located to form an oil blocking peripheral wall 511, and oil droplets can be prevented from dropping into the second air inlets 51 during the baking process by the oil blocking peripheral wall 511.

In order to facilitate the daily maintenance of users, the airflow cover 5 is detachably connected with the hot air baffle 2. When the airflow cover 5 is cleaned, the airflow cover is only required to be detached from the hot air baffle 2 and directly washed by hand or put into a washing device such as a dish washer and the like for washing. Specifically, in this embodiment, as shown in fig. 8 to 9, the positioning plates 56 are vertically extended downward from the front and rear ends of the left sidewall of the airflow hood 5, the limiting plates 55 are horizontally extended outward from the front and rear ends of the right sidewall of the airflow hood 5, and the positioning holes 24 for inserting the corresponding positioning plates 56 and the limiting holes 23 for inserting the corresponding limiting plates 55 are respectively formed at the corresponding positions of the hot air baffle 2. The mounting process of the airflow hood 5 is as follows: the limiting plates 55 of the airflow cover 5 firstly pass through the corresponding limiting holes 23 on the hot air baffle 2, the limiting plates 55 move towards the edges of the corresponding limiting holes 23, the upper surfaces of the limiting plates 55 are tightly attached to the lower surfaces of the corresponding limiting holes 23, then the positioning plates 56 of the airflow cover 5 are respectively inserted into the corresponding positioning holes 24 of the hot air baffle 2 until the lower surfaces of the positioning plates 56 are tightly attached to the upper surfaces of the corresponding positioning holes 24, and the installation of the airflow cover 5 on the hot air baffle 2 is completed. The disassembly process is as follows: firstly, the positioning plates 56 of the airflow hood 5 are pulled out upwards, and then the positioning plates 55 of the airflow hood 5 are moved towards the positioning plates 56 until the positioning plates 55 can be completely separated from the limiting holes 23 of the hot air baffle 2, so that the airflow hood 5 is detached from the hot air baffle 2.

The working process of the baking mode in the invention is as follows: baking trays (or tinfoil paper is laid in the baking trays 6) are placed in the inner container 1, the heating pipes and the driving motor 3 are opened, and the centrifugal fan blades 31 and the axial flow fan blades 32 rotate simultaneously. The air in the inner container 1 enters the diversion space 50 through the second air inlet 51 of the airflow cover 5, most of the air entering the diversion space 50 is then sucked into the hot air chamber 20 through the first air inlet 21 of the hot air baffle 2 for heating, the rest air moves upwards through the second air outlet 52 under the action of the axial flow fan blade 32, the air entering the hot air chamber 20 is heated and then returns to the inner container 1 through the first air outlets 22 around the hot air baffle 2, and the process continuously circulates to form a hot air circulation of the baking function. Due to the airflow from bottom to top formed at the second air outlet 52, the flue gas in the baking process can be blocked from moving downwards, and the flue gas can move upwards and is discharged from the air outlet 11 by combining the negative pressure effect of the air outlet 11. Due to the blocking effect of the airflow cover 5, oil stains generated in the food baking process cannot enter the hot air chamber 20 and are collected in the oil receiving groove 54 of the airflow cover 5, and when a user needs to clean, the user only needs to detach the airflow cover 5 and clean the airflow cover 5.

The working process of the drying mode in the invention is as follows: putting each baking pan 6 into the inner container 1, putting the food to be dried on the baking pan 6, and opening each heating pipe and the driving motor 3. The cold air in the hot air chamber 20 is heated, the cold air in the inner container 1 is sucked into the hot air chamber 20 to be mixed with the hot air, the hot air upwards enters the inner container 1 through the first air outlet 22 of the hot air baffle 2 under the rotation of the centrifugal fan blades 31, the hot air dries food through the opening of the baking pan 6, meanwhile, the hot air enters the baking pan 6 from bottom to top through the air vents 61 on the baking pans 6 to dry the food, and water vapor generated in the food drying process is directly discharged under the action of negative pressure at the air outlet 11. The second air outlet 52 of the airflow hood 5 forms an airflow from bottom to top, and the second air outlet 52 is opposite to the air outlet 11 from top to bottom, so that moisture generated in the drying process can be rapidly taken away from bottom to top through the vent holes 61 on the drying pans 6.

Thus, the drying process is repeatedly circulated, and under the negative pressure action at the exhaust port 11 of the inner container 1, the water vapor is slowly exhausted out of the inner container 1 through the exhaust hole 71, rapidly enters the exhaust channel 80 and is finally exhausted under the action of the exhaust fan 9. According to the invention, the hot air circulation in the vertical direction is formed in the inner container 1, the discharge path of water vapor is shortened, the direction is exactly the same as the hot air circulation direction, and the drying rate is obviously improved.