Microwave sectional drying device with heat recovery device

Abstract

The present application relates to the field of drying device, especially a microwave segmented drying device with heat recovery device, including machine body; long conveying belt arranged on the machine body, the long conveying belt is used for conveying the material to be dried; a plurality of microwave generators arranged on the machine body, the microwave generator is used for heating and drying material; multistage heat cycle module arranged on the machine body, the multistage heat cycle module includes; feed assembly and cooling assembly, the feed assembly and cooling assembly are respectively arranged on the feed end and discharge end of the machine body; the circulation pipe group connected with the machine body, the feed assembly and the cooling assembly in turn; by setting multistage heat cycle module, the waste heat of drying is recycled, the humid hot air generated by microwave drying is two-stage cascade reuse, first, the high-temperature and high-humidity waste gas is guided to the feed end by one-stage circulation, and the preheating and surface uniform moisture conditioning of material are realized while the light impurity wind selection is removed.

Description

Technical Field

[0001] This invention relates to the field of drying equipment, and in particular to a microwave segmented drying device with a heat recovery device. Background Technology

[0002] In the processing of granular oilseed crop seeds, microwave drying is a crucial step in controlling the moisture content of the finished product, killing insect eggs, and inactivating lipoxygenase activity. Currently, conveyor belt continuous microwave drying equipment is widely used in the industry. This type of equipment enables continuous, flat conveying of materials and uniform heating, offering advantages such as short drying cycles, high heating efficiency, and good retention of the nutritional quality of the finished product. It has become the mainstream technology for drying oilseed seeds. However, current conveyor belt continuous microwave drying equipment still has certain shortcomings when drying granular oilseed crop seeds:

[0003] Firstly, in the continuous operation of actual production lines, the equipment is usually used in conjunction with the front-end multi-stage screening process and the back-end forced cooling process. After screening to remove chaff and light impurities, materials such as soybeans or camellia seeds enter the drying chamber directly at room temperature. Microwave energy must first be used to heat the material as a whole before it can enter the moisture vaporization stage. This part of the heating energy consumption occupies the effective drying time and also extends the length of the pre-processing production line. At the same time, the high-temperature and high-humidity exhaust gas continuously discharged from the drying chamber carries a large amount of sensible heat. Currently, it is mostly directly discharged or preheated through a partition heat exchanger, without being graded and reused according to the temperature and humidity requirements of the front and rear processes. There is significant room for improvement in overall thermal efficiency. More importantly, if the high-temperature material in the discharge stage is directly forced to be blown by room-temperature dry and cold air, the large temperature difference between the inside and outside of the grains can easily generate internal stress, increasing the proportion of cracking and bursting. Moreover, the continuous action of dry and cold air will cause the surface moisture to dissipate rapidly, resulting in the finished product moisture content being lower than the safe storage limit. This not only causes weight loss due to dryness but also has an adverse effect on the fullness of the grains and the taste of subsequent processing. Summary of the Invention

[0004] In view of the above-mentioned technical problems, the present invention is proposed.

[0005] Therefore, the object of the present invention is to provide a microwave segmented drying device with a heat recovery device.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] A microwave segmented drying device with a heat recovery unit includes,

[0008] Organism;

[0009] A long conveyor belt is installed on the machine body, which is used to transport the material to be dried;

[0010] Several microwave generators are installed on the machine body, and the microwave generators are used to heat and dry materials;

[0011] A multi-stage thermal circulation module is installed in the body, the multi-stage thermal circulation module includes;

[0012] The feeding assembly and the cooling assembly are respectively disposed at the feeding end and the discharging end of the machine body;

[0013] A circulation pipe assembly is sequentially connected to the machine body, the feeding component, and the cooling component. The circulation pipe assembly is used to guide the dried, hot and humid air to the feeding component for air separation, impurity removal, and preheating and conditioning of the falling material. At the same time, it is also used to transport the air that has been dehumidified by heat exchange in the feeding component to the cooling component for slow cooling and moisture control of the dried material, thereby inhibiting excessive dehydration of the material.

[0014] As a preferred embodiment of the microwave segmented drying device with heat recovery device of the present invention, the feeding assembly includes a feeding box fixedly installed at the feeding end of the machine body, and the feeding box has a feeding port.

[0015] As a preferred embodiment of the microwave segmented drying device with heat recovery device of the present invention, wherein: a guide chute, a distribution chute and a return air chamber baffle are fixedly installed in the feeding box, and the distribution chute is located at the end of the inclined surface of the guide chute.

[0016] As a preferred embodiment of the microwave segmented drying device with heat recovery device of the present invention, wherein: a waste bin is fixedly installed on the feed box, and the waste bin is connected to the end of the waste channel.

[0017] As a preferred embodiment of the microwave segmented drying device with heat recovery device of the present invention, wherein: the material distribution chute and the return air chamber partition form a waste channel and an air circulation channel, the material guide chute and the material distribution chute form a material discharge channel, and the feed box is provided with a discharge port communicating with the discharge channel.

[0018] As a preferred embodiment of the microwave segmented drying device with heat recovery device of the present invention, the cooling component includes a wind box, which is fixedly installed at the discharge end of the machine body by a mounting bracket, and the air outlet of the wind box faces the material on the surface of the long conveyor belt at the discharge end.

[0019] As a preferred embodiment of the microwave segmented drying device with heat recovery device of the present invention, the circulation pipe group includes a collector pipe fixedly installed on the machine body, a primary circulation pipe fixedly installed in the middle of the collector pipe, the end of the primary circulation pipe passing through the machine body and communicating with the feed box, and a fan is provided at both ends of the collector pipe and the connection with the machine body, the fan being used to extract the hot and humid air inside the machine body.

[0020] As a preferred embodiment of the microwave segmented drying device with heat recovery device of the present invention, a secondary circulation pipe is fixedly installed on the machine body, the end of the secondary circulation pipe is connected to the air box, and a filter screen is provided at the connection between the primary circulation pipe and the feed box, as well as on the guide chute.

[0021] As a preferred embodiment of the microwave segmented drying device with heat recovery device of the present invention, it further includes a discharge conveyor belt, which is located at the discharge end of the machine body and is lower than the height of the long conveyor belt, so as to receive the dried and slowly cooled material.

[0022] As a preferred embodiment of the microwave segmented drying device with heat recovery device of the present invention, wherein: a set of idler rollers is provided in the machine body, the set of idler rollers is used to support the long conveyor belt and lift up both sides of the long conveyor belt, forming a shape in which the middle of the long conveyor belt is low and the two sides are high.

[0023] The beneficial effects of the microwave segmented drying apparatus with heat recovery device of the present invention are as follows:

[0024] By setting up a multi-stage thermal circulation module, the waste heat from drying is recovered and utilized. The humid and hot air generated by microwave drying is reused in two stages. First, the high-temperature and high-humidity waste gas is guided to the feeding end through a primary circulation. While removing light impurities through air separation, the material is preheated and its surface is uniformly moisturized and conditioned. This eliminates the need for an independent air separation source and some front-end screening processes, shortens the pre-processing production line, and avoids the problem of surface drying and crusting caused by dry air preheating. It ensures smooth internal moisture migration during the drying process and reduces the risk of cracking caused by uneven moisture loss of the grains during microwave heating. Then, the warm and humid air after heat exchange and dehumidification is guided to the discharge end to form a gradient cooling path. Compared with the direct and rapid cooling method of dry and cold air in the existing technology, this method can reduce the temperature difference between the inside and outside of the grains, reduce thermal stress cracking, and at the same time, suppress excessive surface dehydration by balancing the moisture effect, stabilizing the moisture content of the finished product within a safe storage range, reducing dry weight loss, and maintaining the fullness and edible quality of the material. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0027] Figure 2 This is a schematic diagram of the internal three-dimensional structure of the present invention.

[0028] Figure 3 This is a three-dimensional structural diagram of the long conveyor belt, idler roller group, and fan part of the present invention.

[0029] Figure 4 This is a three-dimensional structural diagram of the material guide chute, return air chamber baffle, and material distribution chute of the present invention.

[0030] Figure 5 This is a cross-sectional view of the waste bin, feed bin, and feed inlet of the present invention.

[0031] Figure 6 This is a partial structural cross-sectional view of the primary circulation pipe and the secondary circulation pipe of the present invention.

[0032] Figure 7 This is a three-dimensional structural diagram of the mounting frame and bellows portion of the present invention.

[0033] In the diagram: 1. Machine body; 2. Long conveyor belt; 3. Microwave generator; 4. Multi-stage heat circulation module; 41. Feeding assembly; 411. Guide chute; 412. Return air chamber baffle; 413. Distributor chute; 414. Waste bin; 415. Feeding bin; 416. Feed inlet; 417. Discharge outlet; 42. Cooling assembly; 421. Mounting frame; 422. Air box; 43. Circulation pipe assembly; 431. Collector pipe; 432. Primary circulation pipe; 433. Secondary circulation pipe; 5. Idler roller assembly; 6. Discharge conveyor belt; 7. Fan. Detailed Implementation

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0035] Reference Figures 1-7 This embodiment provides a microwave segmented drying device with a heat recovery device, which includes: a body 1; a long conveyor belt 2 disposed on the body 1 for conveying the material to be dried; a plurality of microwave generators 3 disposed on the body 1 for heating the material to be dried; and a multi-stage heat circulation module 4 disposed on the body 1.

[0036] The multi-stage thermal circulation module 4 includes: a feeding component 41 and a cooling component 42, which are respectively located at the feeding end and the discharging end of the machine body 1; and a circulation pipe group 43 that is sequentially connected to the machine body 1, the feeding component 41 and the cooling component 42. The circulation pipe group 43 is used to guide the dried humid air to the feeding component 41 in a primary circulation to remove impurities and preheat and condition the falling material. It is also used to transport the air that has been dehumidified by the feeding component 41 to the cooling component 42 to slowly cool and regulate the moisture content of the dried material and prevent excessive dehydration.

[0037] It should be noted that this embodiment uses granular oilseed crop seeds as an example, such as soybeans and camellia seeds, but the technical solution of the present invention is not limited to this. Those skilled in the art will understand that the present invention is also applicable to other granular oilseed seeds with heat-sensitive and hygroscopic properties, such as sesame seeds and sunflower kernels.

[0038] Several microwave generators 3 are arranged along the conveying direction of the long conveyor belt 2; the feeding assembly 41 can achieve air separation and impurity removal of materials by airflow guidance, removing light impurities and dust. At the same time, the heat of the humid air is transferred to the room temperature materials to preheat them, thereby increasing the initial temperature of the materials when they enter the main drying chamber, providing favorable conditions for subsequent microwave drying.

[0039] The cooling component 42 can achieve gentle cooling of the material, avoiding internal stress caused by rapid cooling. At the same time, the cooling component 42 can also regulate the surface moisture of the material to prevent excessive moisture loss, thereby inhibiting the occurrence of material cracking and maintaining the fullness of the material.

[0040] The primary function of the circulation tube assembly 43 is to guide the humid and hot air generated in the drying chamber to the feeding assembly 41 through a primary circulation method. In the feeding assembly 41, the heat of the humid and hot air is used to perform air separation, impurity removal, and preheating and conditioning on the falling material. After exchanging heat with the material, the temperature and humidity of the humid and hot air are reduced.

[0041] The second function of the circulation tube assembly 43 is to transport the air, which has been heat-exchanged and dehumidified by the feeding assembly 41, to the cooling assembly 42. In the cooling assembly 42, this air is used to slowly cool and regulate the moisture content of the dried material. In this way, the material can be gently cooled and excessive dehydration can be inhibited, thereby maintaining the quality and weight of the material. The entire circulation process realizes the cascade utilization of heat energy and effective control of humidity.

[0042] Reference Figures 1-7 The machine body 1 is provided with a roller group 5, which is used to support the long conveyor belt 2 and lift up both sides of the long conveyor belt 2, forming a shape where the middle of the long conveyor belt 2 is low and the two sides are high.

[0043] Reference Figures 1-7 It also includes a discharge conveyor belt 6, which is located at the discharge end of the machine body 1 and is lower in height than the long conveyor belt 2.

[0044] It should be noted that the discharge conveyor belt 6 is used to receive the material output by the long conveyor belt 2 and complete the first-stage warm air slow cooling, and transport the material to the second-stage cooling section to complete the deep cooling, forming a gradient cooling path.

[0045] The idler roller assembly 5 consists of several rollers, which are fixed inside the machine body 1 by a bracket. These rollers support and guide the operation of the long conveyor belt 2 and give it a specific cross-sectional shape. To achieve a shape that is low in the middle and high on both sides, the idler roller assembly 5 uses a trough-shaped idler configuration. The middle idler is horizontally positioned, while the idlers on both sides are tilted upwards at a certain angle to form the required groove shape. This ensures that the long conveyor belt 2 can stably maintain its preset shape during operation, providing a stable bearing surface for material conveying and preventing material from falling off the surface of the long conveyor belt 2.

[0046] Reference Figures 1-7 The feeding assembly 41 includes a feeding box 415 fixedly installed at the feeding end of the machine body 1. The feeding box 415 has a feeding port 416. A guide slide 411, a distribution slide 413 and a return air chamber baffle 412 are fixedly installed inside the feeding box 415. The distribution slide 413 is located at the end of the inclined surface of the guide slide 411.

[0047] Reference Figures 1-7 The material distribution chute 413 and the return air chamber partition 412 form a waste material channel and an air circulation channel. The material guide chute 411 and the material distribution chute 413 form a material discharge channel. The feed box 415 has a discharge port 417 that communicates with the discharge channel. A waste box 414 is fixedly installed on the feed box 415 and is connected to the end of the waste material channel.

[0048] It should be noted that after the material enters the feed box 415 through the feed inlet 416, it slides down the surface of the inclined guide sluice 411, and is evenly spread at the end of the sluice to form a continuous thin curtain of material. Then, it falls freely into the sorting area. The hot and humid air sent in by the primary circulation pipe 432 passes horizontally through the falling curtain of material and forms a cross-flow contact with the material. Among them, the full finished material is relatively heavy and is less affected by the airflow thrust. It falls vertically along the material drop channel between the guide sluice 411 and the distribution sluice 413 and is evenly spread on the surface of the long conveyor belt 2 through the drop port 417. Light impurities such as chaff, bran powder, and dust are relatively light and are carried by the airflow over the top edge of the distribution sluice 413 and enter the waste channel between the distribution sluice 413 and the return air chamber partition 412. Finally, it slides into the waste box 414 for collection.

[0049] In addition, the humidity carried by the primary circulating airflow can play a role in uniformly moisturizing and conditioning the surface of the material, avoiding the rapid drying and crusting of the material surface caused by direct blowing of dry air. This ensures that the internal moisture can smoothly migrate to the surface during the subsequent microwave drying process. At the same time, it can reduce the moisture gradient between the inside and outside of the material, reduce the risk of cracking and splitting caused by uneven water loss rate during microwave heating, and improve the granulation rate of the finished product. A certain amount of humidity can also cause fine dust in the airflow to agglomerate and settle, improve the cleanliness of air separation and impurity removal, and reduce the accumulation of fine dust in the circulation pipeline.

[0050] The return air chamber baffle 412, the material distribution chute 413 and the inner wall of the feed box 415 together form the return air chamber. After air separation and heat exchange, the airflow flows upward into the return air chamber and then into the secondary circulation pipe 433 to be transported to the cooling component 42. During the contact between the airflow and the material, the airflow transfers its sensible heat to the room temperature material, thereby increasing the initial temperature of the material and reducing the heating energy consumption of the subsequent microwave drying. At the same time, it replaces the front-end light impurity screening process and shortens the pre-processing production line process.

[0051] Reference Figures 1-7 The cooling component 42 includes a wind box 422, which is fixedly installed on the discharge end of the machine body 1 by a mounting bracket 421. The air outlet of the wind box 422 faces the material on the surface of the long conveyor belt 2 at the discharge end.

[0052] It should be noted that the air box 422 is fixed above the discharge end of the long conveyor belt 2 by the mounting bracket 421. Its air outlet is set as a strip-shaped wide structure along the width of the conveyor belt, which can evenly discharge air along the entire width. The airflow is parallel to the surface of the conveyor belt, ensuring that the material spread on the long conveyor belt 2 is fully and evenly in contact with the airflow. The airflow sent into the air box 422 is warm and humid air that has been heat-exchanged and dehumidified at the feeding end. Its temperature is lower than the surface temperature of the discharged material but higher than the ambient temperature. It can achieve a gentle cooling of high-temperature materials, reduce the temperature difference between the inside and outside of the material grains, and avoid the internal stress caused by sudden cooling that causes the material to burst or crack. At the same time, the airflow has a suitable relative humidity, and its corresponding material equilibrium moisture content matches the safe storage moisture of the finished product. It can inhibit the rapid loss of surface moisture of the material, avoid excessive dehydration of the finished product and the resulting dry loss, and maintain the fullness and edible quality of the material. After the first stage of slow cooling, the material travels along the long conveyor belt 2 to the end, and falls to the discharge conveyor belt 6 by its own weight, entering the subsequent second stage of cooling to complete deep cooling, forming a gradient cooling path from warm air slow cooling to room temperature deep cooling.

[0053] Reference Figures 1-7 The circulation pipe assembly 43 includes a manifold 431 fixedly installed on the machine body 1. A primary circulation pipe 432 is fixedly installed in the middle of the manifold 431. The end of the primary circulation pipe 432 passes through the machine body 1 and is connected to the feed box 415. A fan 7 is provided at both ends of the manifold 431 and the connection point with the machine body 1. The fan 7 is used to extract the hot and humid air inside the machine body 1.

[0054] Reference Figures 1-7 A secondary circulation pipe 433 is fixedly installed on the machine body 1. The end of the secondary circulation pipe 433 is connected to the air box 422. Filter screens are provided at the connection between the primary circulation pipe 432 and the feed box 415, as well as on the guide chute 411.

[0055] It should be noted that the manifold 431 is laid out along the length of the machine body 1. The fans 7 at both ends can draw out the hot and humid air generated in the machine body 1 and collect it into the manifold 431, ensuring uniform dehumidification and stable air pressure in the machine body 1. The primary circulation pipe 432 is led out from the middle of the manifold 431 and directly transports the collected high-temperature and high-humidity air to the sorting area of ​​the feed box 415 to realize the first-level utilization of waste heat. After the airflow completes air sorting and preheating at the feed end, the temperature and humidity decrease. After being collected in the return air cavity, it is transported to the air box 422 at the discharge end by the secondary circulation pipe 433 to realize the second-level cascade reuse of heat and humidity.

[0056] The filter screen at the connection between the primary circulation pipe 432 and the feed box 415 is a primary filter screen, which can filter out trace amounts of chaff and dust carried in the humid and hot airflow, preventing impurities from entering the feed box 415 with the airflow and contaminating the material to be dried; the filter screen at the return air inlet on the side of the guide chute 411 can block solid impurities such as chaff from being sucked into the return air chamber and the secondary circulation pipe 433, ensuring that the circulation pipe is unobstructed, and at the same time preventing impurities from being blown to the discharge end with the secondary airflow and contaminating the finished material.

[0057] During operation, the microwave generator 3 inside the machine body 1 is first started and run at low power to preheat the drying chamber. At the same time, the fans 7 at both ends of the collector pipe 431 are started. The heated airflow inside the machine body 1 enters the collector pipe 431 after being filtered by the filter screen. A stable transverse air curtain is formed in advance, so that the feeding end has the ability to remove impurities and preheat. Then, the feeding process is started, and the finished material to be dried is conveyed from the previous screening process to the feed port 416 of the feeding box 415. After falling into the feeding box 415, it slides down along the inclined guide slide 411 to form a continuous and uniformly thick falling material curtain. It enters the sorting area in a free-falling state. At the same time, the fans 7 continue to operate, and the high temperature and high humidity air collected in the collector pipe 431 is conveyed to the sorting area of ​​the feeding box 415 through the primary circulation pipe 432. It passes laterally through the falling material curtain and interacts with the material. Cross-flow contact is formed: the full finished material is relatively heavy and less affected by the lateral thrust of the airflow. It falls vertically along the material drop channel between the guide chute 411 and the distribution chute 413, and is evenly spread to the feed end of the long conveyor belt 2 through the drop port 417. It then enters the drying chamber at a uniform speed with the long conveyor belt 2. Light impurities such as chaff, bran powder, and dust are relatively light and are carried by the airflow through the waste channel, eventually sliding into the waste bin 414 for collection. During this process, the humid and hot air transfers its sensible heat to the room temperature material, preheating the material before it enters the drying chamber, reducing the proportion of microwave energy used for material heating, and improving the effective drying efficiency. At the same time, the appropriate humidity carried by the airflow plays a role in uniformly moisturizing and conditioning the surface of the material, reducing the moisture gradient between the inside and outside of the grains, avoiding rapid drying and crusting of the surface caused by dry air blowing, and ensuring that the internal moisture can smoothly migrate to the surface during the subsequent drying process.

[0058] At the same time, several microwave generators 3 inside the machine body 1 continuously radiate microwaves to heat and dry the material laid flat on the long conveyor belt 2 in segments; the water molecules inside the material are oscillated and heated by the microwaves, and the moisture migrates from the inside to the outside and vaporizes, so that the drying chamber continuously generates hot and humid air.

[0059] After air separation and heat exchange, the airflow temperature decreases and humidity slightly drops. It then passes through the return air chamber and is conveyed via the secondary circulation pipe 433 to the air box 422 at the discharge end of the machine body 1. The airflow is evenly blown out through the wide, strip-shaped air outlet of the air box 422, sweeping parallel to the material surface at the discharge end of the long conveyor belt 2, providing a primary warm air cooling for the freshly dried, high-temperature material. Because the airflow temperature is lower than the material surface temperature but higher than the ambient temperature, the material cools down gradually, reducing the temperature difference between the inside and outside of the grains and preventing internal stress caused by sudden cooling from leading to cracking or bursting. Simultaneously, the airflow carries a relative humidity matching the safe storage moisture content of the material, inhibiting rapid moisture loss from the material surface, preventing excessive dehydration of the finished product and maintaining the fullness and edible quality of the material.

[0060] After being cooled by warm air in the first stage, the material travels to the end of the long conveyor belt 2 and falls onto the lower discharge conveyor belt 6 by its own weight. It is then conveyed forward by the discharge conveyor belt 6 into the second cooling section, where it is further cooled to a temperature that meets the requirements for packaging and storage by ambient air cooling, forming a gradient cooling path from warm air cooling to ambient temperature deep cooling. Finally, the material that has completed the entire process of drying, cooling and humidity control is output from the discharge end and enters the subsequent processes.

[0061] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A microwave segmented drying device with a heat recovery unit, characterized in that: include, Body (1); A long conveyor belt (2) is installed on the machine body (1), and the long conveyor belt (2) is used to transport the material to be dried; Several microwave generators (3) are installed on the machine body (1), and the microwave generators (3) are used to heat and dry materials; A multi-stage thermal circulation module (4) is disposed in the body (1), the multi-stage thermal circulation module (4) comprising: Feeding assembly (41) and cooling assembly (42), wherein the feeding assembly (41) and cooling assembly (42) are respectively disposed at the feeding end and the discharging end of the machine body (1); A circulation pipe assembly (43) is sequentially connected to the machine body (1), the feeding assembly (41), and the cooling assembly (42). The circulation pipe assembly (43) is used to guide the dried hot and humid air to the feeding assembly (41) in a primary circulation, and to perform air separation and preheating conditioning on the falling material. At the same time, it is also used to transport the air after heat exchange and dehumidification by the feeding assembly (41) to the cooling assembly (42), and to perform slow cooling and moisture regulation on the dried material, so as to inhibit excessive dehydration of the material.

2. The microwave segmented drying device with heat recovery unit as described in claim 1, characterized in that: The feeding assembly (41) includes a feeding box (415) fixedly installed at the feeding end of the machine body (1), and the feeding box (415) has a feeding port (416).

3. The microwave segmented drying device with heat recovery unit as described in claim 2, characterized in that: The feed box (415) is fixedly installed with a guide chute (411), a distribution chute (413) and a return air chamber baffle (412), and the distribution chute (413) is located at the end of the inclined surface of the guide chute (411).

4. The microwave segmented drying device with heat recovery unit as described in claim 3, characterized in that: A waste bin (414) is fixedly installed on the feed bin (415), and the waste bin (414) is connected to the end of the waste channel.

5. The microwave segmented drying device with heat recovery unit as described in claim 4, characterized in that: The material distribution chute (413) and the return air chamber partition (412) form a waste material channel and an air circulation channel, and the material guide chute (411) and the material distribution chute (413) form a material discharge channel. The feed box (415) is provided with a discharge port (417) that communicates with the discharge channel.

6. The microwave segmented drying device with heat recovery unit as described in claim 5, characterized in that: The cooling component (42) includes a blower box (422), which is fixedly installed on the discharge end of the machine body (1) by a mounting bracket (421). The air outlet of the blower box (422) faces the material on the surface of the long conveyor belt (2) at the discharge end.

7. The microwave segmented drying device with heat recovery unit as described in claim 6, characterized in that: The circulation pipe assembly (43) includes a manifold (431) fixedly installed on the machine body (1). A primary circulation pipe (432) is fixedly installed in the middle of the manifold (431). The end of the primary circulation pipe (432) passes through the machine body (1) and is connected to the feed box (415). Fans (7) are provided at both ends of the manifold (431) and the connection points with the machine body (1). The fans (7) are used to extract the hot and humid air inside the machine body (1).

8. The microwave segmented drying device with heat recovery unit as described in claim 7, characterized in that: A secondary circulation pipe (433) is fixedly installed on the machine body (1). The end of the secondary circulation pipe (433) is connected to the air box (422). Filter screens are provided at the connection between the primary circulation pipe (432) and the feed box (415), as well as on the guide chute (411).

9. The microwave segmented drying device with heat recovery unit as described in claim 8, characterized in that: It also includes a discharge conveyor belt (6), which is located at the discharge end of the machine body (1) and the height of the discharge conveyor belt (6) is lower than that of the long conveyor belt (2) to receive the dried and slowly cooled material.

10. The microwave segmented drying device with heat recovery unit as described in claim 9, characterized in that: The machine body (1) is provided with a roller group (5), which is used to support the long conveyor belt (2) and lift up both sides of the long conveyor belt (2) to form a shape where the middle of the long conveyor belt (2) is low and the two sides are high.

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