Seven-layer drying machine for food production

Abstract

The invention discloses a seven-layer dryer for food production, which comprises a drying channel communicated with a hot air central unit and a moisture absorber; the number of the conveying mechanisms is seven, and the conveying mechanisms are fixedly installed at the middle end of the inner cavity of the drying channel and used for conveying food; and the air outlet boxes are fixedly mounted on the left side and the right side of the inner cavity of the drying channel and used for drying the food conveyed on the conveying mechanism. The technical problems that in the using process of an existing drying machine for food production, food is inconvenient to efficiently dry, the air flowing speed and distribution are difficult to adjust according to different types, humidity and drying stages of the food, and therefore the food is dried unevenly are solved.

Description

Technical Field

[0001] The invention relates to the technical field of food drying and processing, in particular to a seven-layer drying machine used for food production. Background Art

[0002] The seven-layer dryer used in food production is a type of drying equipment. It is a high-efficiency equipment widely used in the food industry, especially in the process of dehydrating raw materials or finished products. This dryer gradually removes moisture from the material through multiple layers of conveyor belts, thereby achieving the purpose of extending the shelf life of the product and improving the storage conditions. The seven-layer dryer usually adopts a continuous operation method, and the material to be dried is evenly spread on the top conveyor belt. The front and back positions of the seven layers of conveyor belts are different, so that the food on the first layer of conveyor belt can fall on the second layer of conveyor belt, and finally fall on the seventh layer of conveyor belt. As the conveyor belt moves slowly, the material falls layer by layer, and each layer is affected by hot air, thereby gradually reducing its water content. By adjusting the parameters such as temperature, humidity and air flow rate of each layer, the best drying effect for different materials can be achieved.

[0003] Existing dryers for food production are not convenient for efficiently drying food during use, and it is difficult to adjust the speed and distribution of air flow according to the type, humidity and drying stage of the food, which leads to uneven drying of the food. Summary of the invention

[0004] The technical problem to be solved by the present invention is that the existing dryers for food production are not convenient for efficiently drying food during use, and it is difficult to adjust the speed and distribution of air flow according to the type, humidity and drying stage of the food, which leads to uneven drying of the food.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a seven-layer dryer for food production, comprising:

[0006] A drying channel, wherein the drying channel is connected to a hot air central unit and a dehumidifier;

[0007] Conveying mechanisms, the number of which is seven and which are fixedly installed at the middle end of the inner cavity of the drying channel and are used to convey food;

[0008] The air outlet box is fixedly installed on the left and right sides of the inner cavity of the drying channel to dry the food transported by the conveying mechanism.

[0009] As a preferred embodiment of the seven-layer dryer for food production described in the present invention, the air outlet ends of the hot air central unit are respectively connected to the first hot air duct and the second hot air duct, the air outlet end of the first hot air duct penetrates to the top of the inner cavity of the drying channel and is connected to the air outlet box on the right, and the air outlet end of the second hot air duct penetrates to the bottom of the inner cavity of the drying channel and is connected to the air outlet box on the left.

[0010] As a preferred embodiment of the seven-layer dryer for food production described in the present invention, the air inlet end of the desiccant is connected to a first desiccant tube and a second desiccant tube, the air inlet end of the first desiccant tube passes through the bottom of the inner cavity of the drying channel, and the air inlet end of the second desiccant tube passes through the top of the inner cavity of the drying channel.

[0011] As a preferred solution of the seven-layer dryer for food production described in the present invention, the conveying mechanism includes a first conveying frame and a second conveying frame, and a moisture absorption channel is provided on the opposite side of the first conveying frame and the second conveying frame.

[0012] As a preferred embodiment of the seven-layer dryer for food production described in the present invention, wherein: a plurality of conveying cylinders are rotatably connected to the first conveying frame and the second conveying frame, and the surfaces of the conveying cylinders are respectively connected to the first conveyor belt and the second conveyor belt, the first conveyor belt is located inside the first conveying frame, and the second conveyor belt is located inside the second conveying frame.

[0013] As a preferred embodiment of the seven-layer dryer for food production described in the present invention, the bottoms of the first conveying frame and the second conveying frame are fixedly connected with a fixing frame, a conveying motor is fixedly installed on one side of the fixing frame, and the output shaft of the conveying motor is fixedly connected to one end of the conveying cylinder.

[0014] As a preferred embodiment of the seven-layer dryer for food production described in the present invention, a hot air component is fixedly installed in the inner cavity of the air outlet box, and the number of the hot air components is several and evenly arranged in the inner cavity of the air outlet box.

[0015] As a preferred embodiment of the seven-layer dryer for food production described in the present invention, the hot air assembly includes a pipe body, one end of the pipe body is fixedly connected to an elastic air outlet head, one end of the elastic air outlet head is fixedly connected to an elastic air outlet net, and the elastic air outlet head and the elastic air outlet net extend to the outside of the air outlet box.

[0016] As a preferred embodiment of the seven-layer dryer for food production described in the present invention, the surface of the tube body is connected to an air inlet pipe, one end of the air inlet pipe is connected to an electric wind speed regulating valve, and the electric wind speed regulating valve is connected to the first hot air pipe and the second hot air pipe through a pipeline system.

[0017] As a preferred solution of the seven-layer dryer for food production described in the present invention, the elastic air outlet head and the elastic air outlet net are in the shape of a circle, a rectangle and a square.

[0018] Beneficial effects of the present invention:

[0019] 1. The present invention can dry food by setting a drying channel. The drying channel is connected with a hot air central unit and a dehumidifier. The air inlet end of the hot air central unit is connected with a blower. The air inlet end of the blower is connected with a filter. The filter filters the air. The blower draws the filtered air into the interior of the hot air central unit. At the same time, the external high-temperature steam also enters the interior of the hot air central unit. The high-temperature steam and air enter different channels inside the hot air central unit. The air absorbs the heat of the steam and converts it into high-temperature air. The high-temperature air enters the first hot air pipe and the second hot air pipe. The blower pressurizes the air. The inner cavity of the drying channel is fixedly installed with A humidity sensor is electrically connected to a controller on the drying channel. The humidity sensor transmits a detection signal to the controller. When the detected humidity is higher than the set humidity, the controller starts the desiccant. The desiccant extracts moisture from the inner cavity of the drying channel through the first desiccant tube and the second desiccant tube to avoid moisture resorption in the inner cavity of the drying channel and improve the drying efficiency. During the process of the first desiccant tube and the second desiccant tube extracting moisture, the moisture in the inner cavity of the drying channel is discharged through the top and bottom of the inner cavity, and the moisture can pass through the seven-layer conveying mechanism. A desiccant channel is provided on the conveying mechanism so that the moisture can pass through the middle part of the conveying mechanism, further improving the moisture discharge efficiency.

[0020] 2. The number of conveying mechanisms of the present invention is seven, and the front and rear positions of the seven conveying mechanisms are different and staggered, so that the food on the first conveying mechanism can fall on the second conveying mechanism, and finally fall on the seventh conveying mechanism. As the conveying mechanism moves slowly, the food falls layer by layer, and is affected by hot air every time it passes through a layer, thereby gradually reducing its water content. During the operation of the conveying mechanism, the output shaft of the conveying motor drives a plurality of conveying drums to work synchronously, and the conveying drum drives the first conveyor belt and the second conveyor belt to rotate. The first conveyor belt and the second conveyor belt rotate in the inner cavity of the first conveyor rack and the second conveyor rack, and slowly convey the food. During the conveying process, the hot air component performs hot air drying on the food, and the fixed frame supports and fixes the bottom of the first conveyor rack and the second conveyor rack. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention;

[0022] Figure 2 The conveying mechanism of the present invention explodes Figure 1 ;

[0023] Figure 3 The conveying mechanism of the present invention explodes Figure 2 ;

[0024] Figure 4 A partial cross-sectional view of the air outlet box of the present invention;

[0025] Figure 5 It is a schematic diagram of the working state of multiple hot air components of the present invention;

[0026] Figure 6 is a cross-sectional view of a hot air assembly of the present invention;

[0027] Figure 7 It is a schematic diagram of the structure of the limiting member and the adjusting member of the present invention;

[0028] Figure 8 It is a schematic diagram of the elastic air outlet head and the elastic air outlet net of the present invention being circular;

[0029] Fig. 9 It is a schematic diagram of the elastic air outlet head and the elastic air outlet net of the present invention being rectangular;

[0030] Fig.10 This is a schematic diagram showing that the elastic air outlet head and the elastic air outlet net of the present invention are square.

[0031] In the figure: 1, drying channel; 2, conveying mechanism; 201, first conveying frame; 202, conveying cylinder; 203, second conveying frame; 204, second conveying belt; 205, first conveying belt; 206, conveying motor; 207, fixing frame; 208, moisture absorption channel; 3, air outlet box; 4, hot air assembly; 401, tube body; 402, elastic air outlet head; 403, elastic air outlet net; 404, adjusting member; 405, elastic Ring; 406, slide rod; 407, limit piece; 408, sleeve; 409, hydraulic cylinder; 410, mounting flange; 411, shell; 412, electric wind speed regulating valve; 413, air inlet pipe; 414, clamp; 415, bending rod; 416, rotating rod; 417, rotating part; 5, hot air central unit; 6, first hot air pipe; 7, second hot air pipe; 8, desiccant; 9, first desiccant pipe; 10, second desiccant pipe. DETAILED DESCRIPTION

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0033] like Figure 1-Figure 10 As shown, this embodiment provides a seven-layer dryer for food production, including a drying channel 1, and the drying channel 1 is connected to a hot air central unit 5 and a desiccant 8.

[0034] Furthermore, the air outlet ends of the hot air central unit 5 are respectively connected to the first hot air duct 6 and the second hot air duct 7. The air outlet end of the first hot air duct 6 passes through the top of the inner cavity of the drying channel 1 and is connected to the air outlet box 3 on the right. The air outlet end of the second hot air duct 7 passes through the bottom of the inner cavity of the drying channel 1 and is connected to the air outlet box 3 on the left.

[0035] Furthermore, the air inlet end of the desiccant 8 is connected to a first desiccant tube 9 and a second desiccant tube 10 . The air inlet end of the first desiccant tube 9 passes through the bottom of the inner cavity of the drying channel 1 , and the air inlet end of the second desiccant tube 10 passes through the top of the inner cavity of the drying channel 1 .

[0036] The air inlet end of the hot air central unit 5 is connected to a blower, and the air inlet end of the blower is connected to a filter. The filter filters the air, and the blower draws the filtered air into the interior of the hot air central unit 5. At the same time, the external high-temperature steam also enters the interior of the hot air central unit 5. The high-temperature steam and air enter different channels inside the hot air central unit 5. The air absorbs the heat of the steam and converts it into high-temperature air. The high-temperature air enters the first hot air pipe 6 and the second hot air pipe 7, and the blower pressurizes the air.

[0037] The hot air central unit 5 uses steam as the main heat source. The steam delivery pressure is 0.4-0.5MPa. The steam flow rate is not less than 600kg / h of saturated steam. Two DN50 branches are connected to the steam main pipeline. After passing through the proportional control valve, it enters the steam heat exchange coil on the hot air central unit 5. The air inlet fan blows the air out through the steam heat exchange coil to be heated, so that the heat enters the oven with air as the medium to provide heat for drying. After heat exchange, the steam becomes condensed water, which is discharged to the condensed water main pipeline by the steam trap. The amount of steam entering the coil is controlled by the steam proportional control valve to adjust the temperature in the drying room.

[0038] During the working process, high-temperature and high-humidity air is extracted and low-temperature and low-humidity air is replenished. A sensible heat exchanger is set in the air circulation path. The high-temperature and high-humidity air exchanges heat with the low-temperature and low-humidity air, and the heat in the high-temperature and high-humidity air is transferred to the low-temperature and low-humidity air, thereby realizing the initial heat recovery and preheating of fresh air. The air discharged to the outside passes through the evaporator and the heat is transferred to the condenser end. The air that has been preliminarily preheated passes through the condenser again, thereby realizing the secondary waste heat recovery of the exhaust air.

[0039] Six internal circulation fans are evenly arranged inside the seven-layer dryer. The fan specification is 200m³ / h. The fans are arranged in the drying box in the form of heat preservation wind cabinets.

[0040] A humidity sensor is fixedly installed in the inner cavity of the drying channel 1. The humidity sensor is electrically connected to the controller on the drying channel 1. The humidity sensor transmits a detection signal to the controller. When the detected humidity is higher than the set humidity, the controller starts the desiccant 8. The desiccant 8 extracts moisture from the inner cavity of the drying channel 1 through the first desiccant tube 9 and the second desiccant tube 10 to avoid moisture resorption of food in the inner cavity of the drying channel 1 and improve the drying efficiency. During the process of the first desiccant tube 9 and the second desiccant tube 10 extracting moisture, the moisture in the inner cavity of the drying channel 1 is discharged through the top and bottom of the inner cavity, and the moisture can pass through the seven-layer conveying mechanism 2. The conveying mechanism 2 is provided with a desiccant channel 208, so that the moisture can pass through the middle part of the conveying mechanism 2, further improving the moisture discharge efficiency.

[0041] Furthermore, it also includes seven conveying mechanisms 2, which are fixedly installed at the middle end of the inner cavity of the drying channel 1 for conveying food.

[0042] Furthermore, the conveying mechanism 2 includes a first conveying frame 201 and a second conveying frame 203 , and a moisture absorption channel 208 is provided on one side opposite to the first conveying frame 201 and the second conveying frame 203 .

[0043] Furthermore, a plurality of conveying cylinders 202 are rotatably connected to the first conveying frame 201 and the second conveying frame 203 , and the surfaces of the conveying cylinders 202 are respectively connected to the first conveying belt 205 and the second conveying belt 204 . The first conveying belt 205 is located inside the first conveying frame 201 , and the second conveying belt 204 is located inside the second conveying frame 203 .

[0044] Furthermore, a fixing frame 207 is fixedly connected to the bottom of the first conveying frame 201 and the second conveying frame 203 , a conveying motor 206 is fixedly installed on one side of the fixing frame 207 , and an output shaft of the conveying motor 206 is fixedly connected to one end of the conveying cylinder 202 .

[0045] Furthermore, the left and right sides of the fixed frame 207 are fixedly connected with support frames, and the bottom of the support frames is fixedly connected to the bottom of the inner cavity of the drying channel 1 to support and fix the seven-layer conveying mechanism 2.

[0046] Furthermore, the transmission cylinder 202 includes a driving transmission cylinder and a driven transmission cylinder, and the output shaft of the conveying motor 206 is fixedly connected to one end of the driving transmission cylinder.

[0047] Furthermore, there are seven layers of conveying mechanisms 2, and the front and rear positions of the seven layers of conveying mechanisms 2 are different, and they are staggered so that the food on the first layer of conveying mechanism 2 can fall on the second layer of conveying mechanism 2, and finally fall on the seventh layer of conveying mechanism 2. As the conveying mechanism 2 moves slowly, the food falls layer by layer, and is affected by hot air each time it passes through a layer, thereby gradually reducing its water content.

[0048] During the operation of the conveying mechanism 2, the output shaft of the conveying motor 206 drives several conveying drums 202 to work synchronously, and the conveying drum 202 drives the first conveyor belt 205 and the second conveyor belt 204 to rotate. The first conveyor belt 205 and the second conveyor belt 204 rotate in the inner cavity of the first conveyor rack 201 and the second conveyor rack 203, and slowly convey the food. During the conveying process, the hot air component 4 dries the food with hot air, and the fixed frame 207 supports and fixes the bottom of the first conveyor rack 201 and the second conveyor rack 203.

[0049] Furthermore, it also includes an air outlet box 3, which is fixedly installed on the left and right sides of the inner cavity of the drying channel 1 to dry the food transported by the conveying mechanism 2.

[0050] Furthermore, a hot air component 4 is fixedly installed in the inner cavity of the air outlet box 3 , and the number of the hot air components 4 is several and evenly arranged in the inner cavity of the air outlet box 3 .

[0051] By arranging the air outlet boxes 3 on the left and right sides of the inner cavity of the drying channel 1, the hot air component 4 can be installed and fixed to efficiently and evenly dry the food transported on the conveying mechanism 2. The hot air inside the second hot air pipe 7 and the first hot air pipe 6 is discharged through the hot air component 4. Several hot air components 4 are aligned with multiple positions on the left and right sides of the conveying mechanism 2 to dry the food on the conveying mechanism 2. A through hole for use with the hot air component 4 is opened on the opposite side of the air outlet box 3.

[0052] By setting up the hot air component 4, the speed and distribution of the hot air flow can be changed to meet the demand for hot air in different drying stages of the food. When the food just enters the dryer, the conveying mechanism 2 at the top has a higher water content. At this time, the hot air component 4 discharges a higher hot air speed and a larger hot air distribution to quickly take away the surface moisture of the food, promote surface evaporation, and prevent product quality degradation due to local over-humidification. As the food moves downward and passes through each layer of the conveying mechanism 2, its water content gradually decreases. The hot air component 4 at the bottom layer gradually reduces the hot air speed and the hot air distribution area to gradually remove internal moisture rather than surface moisture. When the food moves to the bottom conveying mechanism 2 and is close to the end of the drying process, there is very little remaining moisture in the material. At this time, the hot air component 4 at the bottom further reduces the hot air speed and the hot air distribution area to avoid damage to the food quality due to excessive drying and ensure the final quality of the food.

[0053] Furthermore, the hot air assembly 4 includes a tube body 401, one end of the tube body 401 is fixedly connected to an elastic air outlet head 402, one end of the elastic air outlet head 402 is fixedly connected to an elastic air outlet net 403, and the elastic air outlet head 402 and the elastic air outlet net 403 extend to the outside of the air outlet box 3.

[0054] Furthermore, the surface of the tube body 401 is connected to an air inlet pipe 413 , one end of the air inlet pipe 413 is connected to an electric wind speed regulating valve 412 , and the electric wind speed regulating valve 412 is connected to the first hot air pipe 6 and the second hot air pipe 7 through a pipeline system.

[0055] During the operation of the hot air component 4, the hot air from the first hot air pipe 6 and the second hot air pipe 7 enters the electric wind speed regulating valve 412 through the pipeline system. The electric wind speed regulating valve 412 adjusts the hot air speed. The adjusted hot air enters the inner cavity of the tube body 401, and then enters the elastic air outlet head 402. The hot air in the inner cavity of the elastic air outlet head 402 is discharged through the elastic air outlet net 403 to dry the food on the conveying mechanism 2. The elastic air outlet net 403 filters the particulate matter in the hot air to prevent the food from being contaminated.

[0056] Furthermore, the other end of the tube body 401 is fixedly connected to a shell body 411, and a mounting flange 410 is fixedly sleeved on the surface of the shell body 411, and the mounting flange 410 is fixedly installed on the surface of the air outlet box 3. A hydraulic cylinder 409 is fixedly installed in the inner cavity of the shell body 411, and a sliding rod 406 is fixedly connected to the piston rod of the hydraulic cylinder 409. A sliding sleeve 408 is movably sleeved on the surface of the sliding rod 406, and the sliding sleeve 408 is fixedly installed in the inner cavity of the shell body 411. A plurality of adjusting members 404 are installed at one end of the sliding rod 406, and an elastic ring 405 is fixedly connected to one end of the adjusting member 404. The elastic ring 405 is fixedly installed on the right side of the inner wall of the elastic air outlet 402. Both the elastic ring 405 and the elastic air outlet 402 are made of rubber. A limiting member 407 matching the number of the adjusting members 404 is fixedly installed on the inner wall of the tube body 401, and the surface of the limiting member 407 is movably connected to the inner wall of the elastic air outlet 402, so as to limit the elastic air outlet 402.

[0057] Furthermore, the adjusting member 404 includes a bent rod 415, which is fixedly connected to one end of the sliding rod 406. The bent rod 415 is rotatably connected to a rotating rod 416 on both the front and rear sides. One end of the rotating rod 416 is rotatably connected to a rotating member 417, and the rotating member 417 is fixedly connected to the left side of the elastic ring 405.

[0058] Furthermore, a clamping head 414 is provided at one end of the inner side of the limiting member 407 , and the clamping head 414 is located on the outer side of the rotating rod 416 to limit the rotating rod 416 so that the rotating rod 416 can rotate inwards during the leftward movement.

[0059] When the air outlet distribution of the hot air assembly 4 is adjusted, the piston rod of the hydraulic cylinder 409 drives the sliding rod 406 to slide on the inner wall of the sliding sleeve 408, the sliding rod 406 drives the bending rod 415 to move to the left, the bending rod 415 drives the rotating rod 416 and the rotating member 417 to move synchronously, when the rotating rod 416 moves to the extreme position on the left side, it contacts the clamping head 414, the clamping head 414 limits the rotating rod 416 to rotate inward, the rotating rod 416 drives the rotating member 417 to rotate inward, and the rotating member 417 drives the elastic ring 405 inward. The elastic ring 405 deforms and retracts, and drives the elastic air outlet head 402 and the elastic air outlet net 403 to deform synchronously, so that the elastic air outlet net 403 is concave inwardly. During the concave process of the elastic air outlet head 402, the surface of the limiting member 407 limits the inner wall of the elastic air outlet head 402 to prevent it from deforming to the left. The concave of the elastic air outlet net 403 reduces the air outlet area. When the air outlet area needs to be increased, the piston rod of the control hydraulic cylinder 409 is extended to drive the elastic air outlet head 402 and the elastic air outlet net 403 to expand outwardly.

[0060] Furthermore, the elastic air outlet head 402 and the elastic air outlet net 403 are in a shape of a circle, a rectangle and a square.

[0061] When the elastic air outlet head 402 and the elastic air outlet net 403 are circular, several adjusting parts 404 are installed; when the elastic air outlet head 402 and the elastic air outlet net 403 are rectangular, two relatively arranged adjusting parts 404 are installed; when the elastic air outlet head 402 and the elastic air outlet net 403 are square, four relatively arranged adjusting parts 404 are installed to support and adjust the elastic air outlet heads 402 and the elastic air outlet nets 403 of different shapes.

Claims

1. A seven-layer dryer for food production, characterized in that: include, A drying passage (1), wherein the drying passage (1) is connected to a hot air central unit (5) and a dehumidifier (8); Conveying mechanisms (2), the number of the conveying mechanisms (2) being seven and fixedly mounted at the middle end of the inner cavity of the drying channel (1) for conveying food; An air outlet box (3) is fixedly mounted on the left and right sides of the inner cavity of the drying channel (1) to dry the food conveyed by the conveying mechanism (2).

2. The seven-layer dryer for food production according to claim 1, characterized in that: The air outlet end of the hot air central unit (5) is respectively connected to a first hot air pipe (6) and a second hot air pipe (7); the air outlet end of the first hot air pipe (6) passes through the top of the inner cavity of the drying channel (1) and is connected to the air outlet box (3) on the right side; the air outlet end of the second hot air pipe (7) passes through the bottom of the inner cavity of the drying channel (1) and is connected to the air outlet box (3) on the left side.

3. The seven-layer dryer for food production according to claim 1, characterized in that: The air inlet end of the desiccant (8) is connected to a first desiccant tube (9) and a second desiccant tube (10); the air inlet end of the first desiccant tube (9) passes through the bottom of the inner cavity of the drying channel (1), and the air inlet end of the second desiccant tube (10) passes through the top of the inner cavity of the drying channel (1).

4. The seven-layer dryer for food production according to claim 1, characterized in that: The conveying mechanism (2) comprises a first conveying frame (201) and a second conveying frame (203), and a moisture absorption channel (208) is provided on one side opposite to the first conveying frame (201) and the second conveying frame (203).

5. The seven-layer dryer for food production as claimed in claim 4, characterized in that: A plurality of conveying cylinders (202) are rotatably connected to the first conveying frame (201) and the second conveying frame (203); the surfaces of the conveying cylinders (202) are respectively connected in a driving manner to a first conveying belt (205) and a second conveying belt (204); the first conveying belt (205) is located inside the first conveying frame (201), and the second conveying belt (204) is located inside the second conveying frame (203).

6. The seven-layer dryer for food production as claimed in claim 5, characterized in that: A fixing frame (207) is fixedly connected to the bottom of the first conveying frame (201) and the second conveying frame (203), a conveying motor (206) is fixedly mounted on one side of the fixing frame (207), and an output shaft of the conveying motor (206) is fixedly connected to one end of the conveying cylinder (202).

7. The seven-layer dryer for food production as claimed in claim 1, characterized in that: A hot air component (4) is fixedly mounted in the inner cavity of the air outlet box (3); the hot air components (4) are multiple in number and are evenly arranged in the inner cavity of the air outlet box (3).

8. The seven-layer dryer for food production as claimed in claim 1, characterized in that: The hot air assembly (4) comprises a tube body (401), one end of the tube body (401) is fixedly connected to an elastic air outlet head (402), one end of the elastic air outlet head (402) is fixedly connected to an elastic air outlet net (403), and the elastic air outlet head (402) and the elastic air outlet net (403) extend to the outside of the air outlet box (3).

9. The seven-layer dryer for food production according to claim 8, characterized in that: The surface of the tube body (401) is connected to an air inlet pipe (413), one end of the air inlet pipe (413) is connected to an electric wind speed regulating valve (412), and the electric wind speed regulating valve (412) is connected to the first hot air pipe (6) and the second hot air pipe (7) through a pipeline system.

10. The seven-layer dryer for food production according to claim 9, characterized in that: The elastic air outlet head (402) and the elastic air outlet net (403) are in the shape of one of a circle, a rectangle and a square.

Images