An American ginseng drying system

Abstract

The present invention provides a drying device and a system for controlling the law of hot air output. The drying device includes a box body and a conveyor belt. The conveyor belt passes through the box body. The air nozzles are located below the conveyor belt and blow hot air upward from the bottom to the top to dry the materials. In the box body, a plurality of nozzles are arranged along the conveying direction of the conveyor belt. Along the conveying direction of the conveyor belt, the distribution density of the nozzles is increasing. By changing the distribution density of the nozzles, the present invention can make the amount of hot air along the conveying direction of the conveyor belt increase more and more, and the drying effect is getting better and better, so as to achieve the effect similar to the countercurrent heat exchange of the heat exchanger and further improve the drying effect.

Description

Technical Field

[0001] The present invention relates to a drying system, and more particularly to a drying device and system with a controlled law of hot air output volume. Background Art

[0002] Currently, in the processing and production of industrial equipment, drying and other processing procedures are often required in some technological processes. Commonly, hot air drying devices are used for drying. In traditional hot air blowing devices, due to unreasonable structural design, during the blowing process, the temperature of the hot air fails to meet the requirements, resulting in poor drying effects and low working efficiency. It also causes moisture to remain on the surface of the equipment. Moreover, these hot air blowing devices cannot be easily moved, bringing a lot of trouble to the staff and wasting the human and material resources of the enterprise. The temperature of existing hot air devices is inconvenient to adjust and the effect is not ideal enough, thus further improvement is needed.

[0003] However, traditional dryers also have the above problems. Under the new situation of energy conservation and emission reduction, their development has been greatly restricted. Traditional heating and drying methods cannot control the heat requirements for drying at different positions according to actual needs in actual production. A unified amount of heat is adopted throughout the drying process, so heat transformation is not carried out according to actual needs, and the actual production requirements cannot be met. Therefore, a drying system that can control the heat distribution is needed to enable the materials to be dried to be efficiently and quickly dried and meet the drying requirements in a short time. Therefore, in view of these deficiencies, a dryer with a simple structure is developed. By changing the distribution density of the nozzles, the quantity of hot air along the conveying direction of the conveyor belt can be made to increase, and the drying effect can be improved. Thus, the effect similar to countercurrent heat exchange of a heat exchanger can be achieved, further improving the drying effect, which is of great significance to industrial production and energy conservation and emission reduction. Summary of the Invention

[0004] In order to overcome the defects and deficiencies existing in the prior art, the present invention provides a drying system with a new structure to further improve the drying effect.

[0005] In order to achieve the above object, the technical solution of the present invention is as follows:

[0006] A drying device with a controlled law of hot air output volume, the drying device comprising a box body and a conveyor belt, the conveyor belt passing through the box body, and air nozzles being located below the conveyor belt and blowing hot air upward from the bottom to the conveyor belt for drying materials; in the box body, a plurality of nozzles are arranged along the conveying direction of the conveyor belt; along the conveying direction of the conveyor belt, the distribution density of the nozzles is increasing.

[0007] As an improvement, along the conveying direction of the conveyor belt, the amplitude of the increasing distribution density of the nozzles gradually increases.

[0008] As an improvement, the output air volume of each nozzle is the same.

[0009] As an improvement, the power device drives the roller, and the roller drives the conveyor belt.

[0010] A drying system, the system includes an air heater and a drying device. The air enters the drying device after being heated by the air heater to dry the material; the drying device includes a box body and a conveyor belt. The conveyor belt passes through the box body. The air nozzles are located below the conveyor belt and blow hot air upward from the bottom to the top of the conveyor belt to dry the material. Inside the box body, along the conveying direction of the conveyor belt, a plurality of nozzles are arranged; along the conveying direction of the conveyor belt, the distribution density of the nozzles is increasing.

[0011] As an improvement, along the conveying direction of the conveyor belt, the amplitude of the increasing distribution density of the nozzles gradually increases.

[0012] As an improvement, the output air volume of each nozzle is the same.

[0013] As an improvement, the power device drives the roller, and the roller drives the conveyor belt.

[0014] As an improvement, the air heater includes a tube side and a shell side. The tube side includes a tube side inlet and an outlet, and the shell side includes a shell side inlet and an outlet. The fluids in the tube side and the shell side exchange heat. The shell side includes a plurality of shell side inlets and one shell side outlet. The shell side outlet is distributed at the lower end on the left side of the shell side, and the plurality of shell side inlets are distributed at the upper end of the shell side, distributed from the left side to the right side of the shell side. A valve is provided on each shell side inlet pipe.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] Through the change of the distribution density of the nozzles, the present invention can make the number of hot air along the conveying direction of the conveyor belt increase more and more, and the drying effect is better and better, so as to achieve the effect similar to the countercurrent heat exchange of the heat exchanger and further improve the drying effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of the drying system of the present invention.

[0018] Figure 2 is a schematic structural diagram of the air heater of the present invention.

[0019] Figure 3 is a schematic structural diagram of the drying device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] The following will make a detailed description of the specific embodiments of the present invention with reference to the drawings.

[0021] In this text, unless otherwise specified, in the case of formulas, " / " represents division, and "×" and "*" represent multiplication.

[0022] In this text, orientation terms such as up, down, left, and right are used to represent the relative positional relationships between various components, and do not represent the actual installation positions.

[0023] Figure 1 The drying system of the present invention is shown. As Figure 1 shown, the system includes an air heater 1 and a drying device 2. After the air is heated in the air heater 1, it enters the drying device 2 to dry the material.

[0024] Figure 2 The air heater 1 of the present application is disclosed. As Figure 2 shown, an air heater 1 that accurately controls the output temperature, the air heater 1 includes a tube side and a shell side. The tube side includes a tube side inlet 11 and an outlet 12, and the shell side includes a shell side inlet 3 and an outlet 4. The fluids in the tube side and the shell side perform heat exchange. As Figure 2 shown, the shell side includes a plurality of shell side inlets 3 and one shell side outlet 4. Among them, the shell side outlet 4 is distributed at the lower end on the left side of the shell side, Figure 1 near the position of the left header 5 of the tube side. The plurality of shell side inlets 3 are distributed at the upper end of the shell side, and are distributed from the left side to the right side of the shell side, that is, arranged along the flow direction of the fluid in the tube side. A valve 7 is provided on each shell side inlet pipe. The flow rate of the fluid entering each shell side inlet is controlled by the valve 7. Air enters from the shell side inlet, is heated by the tube side fluid in the heater, and then exits from the shell side outlet and enters the drying device to dry the material 21. The air coming out of the drying device circulates back to the air heater for heating.

[0025] Preferably, the heat source of the tube side is waste gas, and the waste gas waste heat is used to heat the air.

[0026] In the present invention, by providing a plurality of inlets on the shell side, and the plurality of inlets are arranged along the flow direction of the tube side fluid, so that the heat exchange amounts participated by the shell side fluids at different inlets are different, and the heat exchange amount of the fluid output between the tube side inlet and the tube side outlet gradually increases. By controlling the flow rates of the fluids at each shell side inlet, the temperature of the output fluid can be accurately controlled, and the control speed of the output fluid temperature can be improved.

[0027] The output temperature gradually increases along the flow direction of the fluid in the tube side.

[0028] Preferably, the tube side includes a left header 5 and a right header 6, and the tube side inlet 11 and the outlet 12 are respectively arranged on the left header 5 and the right header 6.

[0029] Preferably, a left tube sheet 8 and a right tube sheet 9 are respectively arranged in the left header 5 and the right header 6, and the heat exchange tubes in the tube side are connected to the left tube sheet and the right tube sheet. The tube side fluid enters from the left header 5, then enters the heat exchange tubes, and then flows out from the right header 6 to complete the heat exchange with the shell side fluid.

[0030] Preferably, the material is medicinal herbs. More preferably, it is American ginseng or cistanche deserticola.

[0031] Preferably, the air heater further includes a controller, the controller is data-connected to the valve 7, and a first temperature sensor is further arranged at the shell side outlet for detecting the temperature of the fluid output from the shell side outlet. The controller is data-connected to the first temperature sensor. The controller controls each valve 7 to perform the following operations according to the temperature detected by the first temperature sensor: opening of the valve 7, closing of the valve 7, and the size of the opening of the valve 7.

[0032] Preferably, the system includes a main pipeline 10, the main pipeline 10 is connected to each shell side inlet 3, and the pipelines between the shell side inlets 3 are connected in parallel. A second temperature sensor is arranged on the main pipeline 10 for detecting the temperature of the fluid entering each inlet. The controller is data-connected to the second temperature sensor. The controller stores the temperature data detected by the first temperature sensor, the temperature data detected by the second temperature sensor, and the data of the opening and closing and the opening degree of each valve in the first database. Therefore, a plurality of historical data are stored in the first database.

[0033] As an improvement, the shell side outlet flow data can also be stored in the first database.

[0034] Preferably, the controller automatically retrieves the data of the opening and closing and the opening degree of the valve in the first database according to the set temperature of the shell side outlet and the detected temperature of the main pipeline.

[0035] As an improvement, the temperature of the main pipeline remains unchanged. The retrieved data is the data closest to the temperature of the shell side outlet. Preferably, the set temperature of the shell side outlet is T, the temperature at the outlet in the database is T1, and the requirement for the retrieved data is the data with the smallest absolute value of the difference (T - T1). By setting like this, the output temperature can be made closest to the set temperature, and then the opening degree of the valve is adjusted according to the detected output temperature, so that the output temperature reaches the set temperature as quickly as possible. 2 The difference is the smallest data. Through such a setting, the output temperature can be made closest to the set temperature, and then the opening degree of the valve is adjusted according to the detected output temperature, so that the output temperature reaches the set temperature as quickly as possible.

[0036] As an improvement, the temperature of the main pipeline changes. The retrieved data is the data closest to the temperature of the shell side outlet and the temperature of the main pipeline. Preferably, the set outlet temperature is T, the temperature at the outlet in the database is T1, the detected temperature of the main pipeline is T2, and the temperature of the main pipeline in the database is T3. The requirement for the retrieved data is (T - T1) 2 +(T2 - T3) 2The minimum data. By setting it in this way, the output temperature can be made closest to the set temperature, and then the opening degree of the valve can be adjusted according to the detected output temperature, so that the output temperature reaches the set temperature as quickly as possible.

[0037] As an improvement, if the output temperature at the shell side outlet needs to be increased, the opening degree of the inlet valve near the left header is reduced, and the opening degree of the inlet valve near the right header is increased, so that the temperature can be increased to the predetermined temperature as soon as possible. If the output temperature of the shell side needs to be decreased, the opening degree of the inlet valve near the left header is increased, and the opening degree of the inlet valve near the right header is decreased, so that the temperature can be decreased to the predetermined temperature as soon as possible.

[0038] As an improvement, the total opening degree of all valves 7 remains unchanged, so that the output flow rate also remains unchanged. Therefore, the present application can adjust the temperature to quickly reach the optimal temperature while keeping the flow rate unchanged.

[0039] Preferably, one valve 7 is opened to the maximum opening degree, and the other valves are closed. The main pipeline temperature and the output temperature are detected, and the temperature data and the valve data are stored in the second database, so as to obtain the output temperature when each valve is opened to the maximum opening degree separately.

[0040] Preferably, the controller automatically retrieves the data in the second database according to the set temperature T at the shell side outlet and the detected temperature of the main pipeline, finds the data when the opening degrees of two adjacent valves, namely the first valve and the second valve, are the largest, where the output temperature data of the first valve is higher than the set temperature but the difference in the higher data is the smallest, and the output temperature data of the second valve is lower than the set temperature but the difference in the lower data is the smallest, and then adjusts the output temperature by adjusting the opening degrees of the two valves.

[0041] As an improvement, the main pipeline temperature remains unchanged. The set temperature at the shell side outlet is T, the data of the adjacent valve with a higher temperature in the second database is Tg, the temperature of the data with a lower temperature is Td, and the retrieved data requirement is (T - Tg) 2 +(T - Td) 2 The minimum data. By setting it in this way, the output temperature can be made closest to the set temperature, and then the opening degree of the valve can be adjusted according to the detected output temperature, so that the output temperature reaches the set temperature as quickly as possible.

[0042] As an improvement, the main pipeline temperature is variable. The set temperature at the shell side outlet is T, the detected main pipeline temperature data is T2, the data of the adjacent valve with a higher temperature in the database is Tg, the temperature of the data with a lower temperature is Td, and the data of the main pipeline is T3. The retrieved data requirement is ((Tg + Td) / 2 - T) 2 +(T3 - T2) 2The minimum data. By setting it in this way, the output temperature can be made closest to the set temperature, and then the opening degree of the valve is adjusted according to the detected output temperature, so that the output temperature reaches the set temperature at the fastest speed.

[0043] As an improvement, when the detected output temperature is higher than the predetermined temperature, the opening degree of the second valve is controlled to increase, and the opening degree of the first valve is controlled to decrease; when the detected output temperature is lower than the predetermined temperature, the opening degree of the second valve is controlled to decrease, and the opening degree of the first valve is controlled to increase. By quickly positioning the two valves that need to be opened before, and then adjusting the opening and closing of the two adjacent valves, the output temperature can quickly reach the predetermined temperature.

[0044] As an improvement, when the detected output temperature is higher than the predetermined temperature, if the requirement is still not met when the opening degree of the second valve is the largest, the first valve is closed, and another valve whose output temperature is lower than that of the second valve when opened alone and adjacent to the second valve is opened, that is, another inlet valve adjacent to the second valve is opened, and the temperature is adjusted by adjusting the opening degrees of the second valve and the other inlet valve. When the detected output temperature is lower than the predetermined temperature, if the requirement is still not met when the opening degree of the first valve is the largest, the second valve is closed, and another valve whose output temperature is higher than that of the first valve when opened alone and adjacent to the first valve is opened. That is, another valve adjacent to the first valve is opened, and the temperature is adjusted by adjusting the opening degrees of the first valve and the other inlet valve.

[0045] Preferably, the total opening degrees of the first valve and the second valve remain unchanged. Thus, the output flow rate also remains unchanged. Therefore, the present application can adjust the temperature to quickly reach the optimal temperature while keeping the flow rate unchanged.

[0046] The present invention also discloses a control method for accurately controlling the outlet temperature of the shell side of the air heater. The temperature of the main pipeline remains unchanged, and mainly includes the following steps:

[0047] 1) Open one valve to the maximum opening degree, and close all other valves. Detect the output temperature, and store the temperature data and valve data in the second database, so as to obtain the output temperature of the shell side when each valve is opened alone to the maximum opening degree.

[0048] 2) The user sets the output temperature T of the shell side. The controller automatically retrieves the data in the second database according to the set output temperature T. If the temperature T is equal to the output temperature of the shell side when a certain valve is opened alone to the maximum opening degree, then control this valve to open and close all other valves.

[0049] 3) If the output temperature of the shell side when a certain valve is opened alone to the maximum opening degree cannot be found in the database, then find two adjacent valves, that is, the data Tg and Td when the opening degrees of the first valve and the second valve are the largest, and it is required that Tg>T>Td, and then adjust the output temperature by adjusting the opening degrees of the two valves.

[0050] 4) When the detected output temperature is higher than the predetermined temperature, control the opening degree of the second valve to increase and the opening degree of the first valve to decrease; when the detected output temperature is lower than the predetermined temperature, control the opening degree of the second valve to decrease and the opening degree of the first valve to increase. By quickly positioning the two valves that need to be opened in the front, and then adjusting the opening and closing of the two adjacent valves, the output temperature can quickly reach the predetermined temperature.

[0051] As an improvement, when the temperature of the main pipeline is variable, the following steps are included:

[0052] 1) Open one valve to the maximum opening degree, close all other valves, detect the output temperature at the shell side outlet and the temperature of the main pipeline, and store the temperature data and valve data in the second database, so as to obtain the output temperature of the shell side corresponding to the temperature of the main pipeline when each valve is opened to the maximum opening degree alone.

[0053] 2) The user sets the output temperature T of the shell side. The controller automatically retrieves the data in the second database according to the set output temperature T and the detected temperature of the main pipeline. At the corresponding temperature of the main pipeline, if the temperature T is equal to the output temperature of the shell side when a certain valve is opened to the maximum opening degree alone, control the valve to open and close all other valves.

[0054] 3) If the output temperature of the shell side when a certain valve is opened to the maximum opening degree alone at the corresponding temperature of the main pipeline cannot be found in the database, the data with a higher temperature of the adjacent valves in the database is Tg, and the data with a lower temperature is Td, that is, the data Tg and Td when the first valve and the second valve are opened to the maximum opening degree, and the data of the main pipeline is T3. The data to be retrieved is ((Tg + Td) / 2 - T) 2 +(T3 - T2) 2 The smallest data. Then adjust the opening degrees of the adjacent valves according to the detected output temperature, so that the output temperature can reach the set temperature as quickly as possible.

[0055] 4) When the detected output temperature is higher than the predetermined temperature, control the opening degree of the second valve to increase and the opening degree of the first valve to decrease; when the detected output temperature is lower than the predetermined temperature, control the opening degree of the second valve to decrease and the opening degree of the first valve to increase. By quickly positioning the two valves that need to be opened in the front, and then adjusting the opening and closing of the two adjacent valves, the output temperature can quickly reach the predetermined temperature.

[0056] 5) When the detected output temperature is higher than the predetermined temperature and the requirement is still not met even when the opening degree of the second valve is at its maximum, close the first valve and open another valve adjacent to the second valve, whose output temperature in the case of being opened separately is lower than that of the second valve, that is, open another inlet valve adjacent to the second valve. When the detected output temperature is lower than the predetermined temperature and the requirement is still not met even when the opening degree of the first valve is at its maximum, close the second valve and open another valve adjacent to the first valve, whose output temperature in the case of being opened separately is higher than that of the first valve. That is, open another valve adjacent to the first valve.

[0057] 6) If the output temperature still does not meet the requirements, continue to repeat step 5) until the output temperature that meets the requirements is finally achieved.

[0058] As an improvement, the air heater is a horizontal shell-and-tube heat exchanger.

[0059] The shell side includes a shell body, and a baffle plate is arranged in the shell body to make the fluid flow through all the tube passes and avoid the problem of short circuit.

[0060] As an improvement, the shell side and the tube side flow countercurrently. Along the flow direction of the fluid in the tube side, from the tube side inlet to the middle position of the tube side, the spacing of the baffle plates continuously increases. Then from the middle position of the tube side to the tube side outlet, the spacing of the baffle plates continuously decreases. Because in the countercurrent process, the heat transfer amount per unit length of the shell side and the tube side along the fluid flow process is relatively uniform, thus making the overall heat transfer effect the best. However, it is found in experiments and simulations that the heat transfer amount in the middle is significantly greater than that at the tube side inlet and outlet. Therefore, by changing the baffle plate spacing, the heat transfer area between the tube side fluid and the shell side fluid in the baffle plates also changes. Therefore, through the area change, the non-uniformity of the heat transfer amount is compensated, so as to further improve the heat transfer efficiency.

[0061] As an improvement, along the flow direction of the fluid in the tube side, from the tube side inlet to the middle position of the tube side, the increasing amplitude of the baffle plate spacing continuously increases. Then from the middle position of the tube side to the tube side outlet, the decreasing amplitude of the baffle plate spacing continuously decreases. The above-mentioned amplitude change can make the heat transfer amount per unit length of the entire fluid motion more uniform and further improve the heat transfer efficiency.

[0062] The baffle plates are arranged vertically and include upper baffle plates and lower baffle plates. The upper baffle plates and the lower baffle plates are arranged at intervals; along the flow direction of the fluid in the shell side, the height of the lower baffle plates extending upward from the inner wall of the bottom shell in the vertical direction gradually increases, and the length of the upper baffle plates extending downward from the inner wall of the upper shell in the vertical direction gradually decreases.

[0063] During the research process, it was found that the baffles of traditional heat exchangers have uneven heat transfer on the cross-section in the fluid flow direction. As the distance from the inlet increases, the density of the heat transfer liquid at the lower part of the shell side is high, so the liquid flows downward, resulting in a significant increase in the heat transfer liquid at the lower part. Therefore, it is necessary to design a heat transfer structure for improvement. Along the fluid flow direction of the present invention, the heights of the upper baffle and the lower baffle change, causing the liquid in the shell side to gradually converge more and more towards the center as it flows, strengthening the heat transfer of the heat exchange tubes around the shell center in the tube shell, changing the past heat transfer method, enhancing the heat transfer efficiency at different positions, making the overall heat transfer uniform, and further achieving the purpose of strengthening heat transfer.

[0064] As an improvement, along the fluid flow direction in the shell side, the height of the lower baffle extending upward from the inner wall of the bottom shell side in the vertical direction gradually increases with an increasing amplitude, and the length of the upper baffle extending downward from the inner wall of the upper shell side in the vertical direction gradually decreases with a decreasing amplitude. Through the change of the above amplitudes, the overall heat transfer can be further made uniform, and the purpose of strengthening heat transfer is further achieved.

[0065] Figure 3 The drying equipment of the present invention is shown. As Figure 3 shown, the drying equipment includes a box body and a conveyor belt 22. The conveyor belt 22 passes through the box body. The air nozzles are located below the conveyor belt 22 and blow hot air upward from the bottom to the top to dry the materials. The power device drives the rollers 23, and the rollers 23 drive the conveyor belt.

[0066] Preferably, in the box body, along the direction of the conveyor belt transmission, a plurality of nozzles are arranged to ensure uniform heating.

[0067] Preferably, along the direction of the conveyor belt transmission, the distribution density of the nozzles becomes larger and larger. Through the change of the distribution density of the nozzles, the amount of hot air along the conveyor belt transmission direction can be made more and more, and the drying effect is better and better, thus achieving the effect similar to the countercurrent heat exchange of the heat exchanger and further improving the drying effect. As a preference, in this case, the air output of all the nozzles is the same.

[0068] Preferably, along the conveyor belt transmission direction, the amplitude of the increasing distribution density of the nozzles gradually increases. Through the above setting, the drying effect can be further improved.

[0069] Preferably, along the conveyor belt transmission direction, the nozzles are evenly distributed. The air output of the nozzles along the conveyor belt transmission direction becomes larger and larger.

[0070] Preferably, along the conveyor belt transmission direction, in the heating area, the amplitude of the increasing air output of the nozzles gradually increases.

[0071] By varying the amount of output air through the nozzle, the amount of hot air along the conveying direction of the conveyor belt can be made to increase continuously, and the drying effect can be improved continuously, so as to achieve an effect similar to the countercurrent heat exchange of a heat exchanger and further improve the drying effect.

[0072] Although the present invention has been disclosed above in preferred embodiments, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be subject to the scope defined by the claims.

Claims

1. A dried American ginseng system, the system comprising an air heater and a drying device, air enters the drying device after being heated by the air heater to dry the material; the drying device comprises a box body and a conveyor belt, the conveyor belt passes through the box body, air nozzles are located below the conveyor belt, and hot air is blown from the bottom upwards to the conveyor belt to dry the material; in the box body, a plurality of air nozzles are arranged along the conveying direction of the conveyor belt; along the conveying direction of the conveyor belt, the distribution density of the air nozzles is increasing; the air heater comprises a tube side and a shell side, the tube side comprises a tube side inlet and an outlet, the shell side comprises a shell side inlet and an outlet, the fluids in the tube side and the shell side perform heat exchange, the shell side comprises a plurality of shell side inlets and one shell side outlet, the shell side outlet is distributed at the lower end on the left side of the shell side, and the plurality of shell side inlets are distributed at the upper end of the shell side, and are distributed from the left side to the right side of the shell side, and a valve is arranged on each shell side inlet pipe; the shell side contains liquid; the material is American ginseng; the air heater is a horizontal shell and tube heat exchanger, the shell side comprises a shell body, a baffle plate is arranged in the shell body, the baffle plate is arranged in the vertical direction, and comprises an upper baffle plate and a lower baffle plate, and the upper baffle plate and the lower baffle plate are arranged at intervals; along the flow direction of the fluid in the shell side, the height of the vertical direction of the lower baffle plate extending upwards from the inner wall of the bottom shell side gradually increases, and the length of the vertical direction of the upper baffle plate extending downwards from the inner wall of the upper shell side gradually decreases, and along the flow direction of the fluid in the shell side, the increasing amplitude of the height of the vertical direction of the lower baffle plate extending upwards from the inner wall of the bottom shell side continuously increases, and the decreasing amplitude of the length of the vertical direction of the upper baffle plate extending downwards from the inner wall of the upper shell side continuously decreases.

2. The drying system according to claim 1, wherein, along the conveying direction of the conveyor belt, the increasing amplitude of the distribution density of the air nozzles gradually increases.

3. The drying system according to claim 1, wherein, the output air volume of each air nozzle is the same.

4. The drying system according to claim 1, wherein, the power device drives the rollers, and the rollers drive the conveyor belt.

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