Low-temperature drying system and drying process for tea leaves in photoelectric combined heating mode

Abstract

The invention discloses a low-temperature tea leaf drying system and drying process in a photoelectric combined heating mode. The low-temperature tea leaf drying system comprises a drying box, a conveying mechanism, a controllable air uniformizing mechanism, a sunlight-imitating light source mechanism, a low-temperature drying mechanism, a sensor module and a main control module. The complete low-temperature drying technological process of tea feeding, conveying, drying, drying parameter adjusting and discharging can be automatically completed. According to the system, parameter monitoring can be effectively carried out in sections, the drying parameters and the air volume of all the sections are controlled in real time based on feedback data, and the continuous, uniform and efficient low-temperature drying technology and system are provided by combining sunlight simulation irradiation and automatic material turning-over equipment; therefore, the drying degree in the tea drying process is uniform, standard and accurate, and the processing quality is improved.

Description

Technical Field

[0001] The invention relates to the technical field of tea drying, and mainly to an automated and efficient low-temperature drying technology, and specifically to a tea low-temperature drying system and a drying process using a photoelectric combined heating method. Background Art

[0002] The processing of Pu'er tea is divided into primary processing and refining. The primary processing process is mainly divided into: picking → spreading → killing → spreading → rolling → sun drying. Sun drying is the drying process after killing and rolling. The important difference between sun drying and other drying methods such as stir-frying and baking is the temperature. Stir-frying, baking and other drying processes have high temperatures, which basically kill the enzyme active substances in the tea leaves. Sun drying uses natural sunlight drying. Since the sunlight drying temperature is low (generally below 60℃), more natural substances in fresh leaves can be retained, forming a strong aroma. After brewing, the aroma is long-lasting and the taste is pure. In addition, the moderate inhibition of microbial activity in the sun drying process also creates potential vitality for the long-term storage of Pu'er tea, which becomes more fragrant as it ages. In the core production areas of Pu'er tea (Pu'er, Lincang, Xishuangbanna, etc.), rainy weather often occurs in summer. After tea farmers or primary processing plants spread, kill, and roll the fresh leaves they have picked, they cannot get sufficient sunlight exposure. The tea leaves cannot be dried in time to the moisture requirements for long-term preservation, resulting in a decrease in the quality of the tea leaves, and even mold and deterioration of the tea leaves, affecting the economic value of Pu'er tea. The failure to dry Pu'er raw tea in time on rainy days has become an urgent problem that tea farmers and primary processing plants need to solve. In addition, in order to ensure sufficient sunlight exposure, the area required for the sun drying field is relatively large. According to the calculation of the thickness of the sun-drying leaves of 1-2 cm, the area required for sun drying 1 ton of tea leaves (water content of about 60%) after rolling is about 300-450 square meters. The investment in the sun drying field is relatively large, and the sun drying field ceiling is generally made of polymer with good light transmittance, which is easy to age and difficult to replace. What's more, the falling of the ceiling material will pollute the tea leaves.

[0003] In summary, the main limitations of traditional sun drying are reflected in the following aspects:

[0004] ① Greatly affected by weather and environment: The processing of sun-dried Pu'er tea is greatly affected by weather and environment. In bad weather conditions such as cloudy and rainy days, the drying process may be hindered, resulting in a decline in the quality of tea. In addition, environmental factors such as air humidity and ambient temperature will also affect the drying process.

[0005] ② Low processing efficiency: The processing efficiency of sun-dried Pu'er tea is relatively low. The drying process requires long periods of natural conditions and cannot meet the needs of large-scale and efficient production. In contrast, the use of low-temperature drying can greatly improve production efficiency.

[0006] ③It is difficult to guarantee the quality: During the sun drying process, due to long-term exposure to the air, the tea leaves are easily contaminated by odors and pollutants in the environment, thus affecting the quality of the tea leaves. In addition, changes in temperature and humidity during the drying process will also affect the quality of the tea leaves.

[0007] ④ Lack of standardization and normalization: Due to the lack of standardization and normalization in the processing of sun-dried Pu'er tea, there are differences in drying techniques and conditions in different regions, resulting in large differences in the quality and taste of the tea.

[0008] However, there are also some problems in the existing automated sun-drying technology. For example, the degree of drying cannot be achieved uniformly. There will be local condition differences in the drying equipment, which makes it impossible to achieve homogeneous control of materials during the entire processing process, and thus it is impossible to achieve fine parameter control, resulting in unstable quality of the final tea product, which cannot meet the needs of high-quality sun-drying technology. Summary of the invention

[0009] In order to solve the deficiencies and defects of the above-mentioned prior art, the inventor has proposed a low-temperature tea drying system after research and development, design and improvement, which can automatically complete the complete low-temperature drying process of tea feeding, transportation, drying, drying parameter adjustment and discharging. The system can effectively monitor parameters within the section interval, and control the drying parameters and air volume of each section in real time based on feedback data, and combine sunlight simulation irradiation and equipment for material turning to provide a continuous, uniform and efficient low-temperature drying process and system to ensure that the degree of drying during the tea drying process is uniform, standard and accurate, and improve the processing quality.

[0010] Specifically, the working principle of the present invention is: using photoelectric combined heating, providing hot air required for drying through the circulation pipeline and electric hot air blower arrangement, through the controllable air equalization mechanism and segmented air equalization plates, temperature and humidity sensor arrangement, imitating sunlight light source, material turning control and other technical combinations, to achieve the homogenization of tea materials, high precision, uniform drying automatic low-temperature drying process.

[0011] First, the photoelectric combined heating technology uses multiple layers of light source components, which are installed above each layer of conveyor belt to simulate sunlight. Each layer of light source components includes a lamp tube and a lamp rack, which are suspended on the two opposite sides of the drying box through the lamp rack. The lamp tube is installed under the lamp rack to illuminate the upper surface of the conveyor belt where the tea leaves are located. The light intensity of the light source component is adjustable, and the light intensity and the number of light sources can be adjusted as needed.

[0012] Secondly, the circulation pipe and electric hot air blower are used to dry the tea leaves inside the drying box. The electric hot air blower is connected to the drying box through the circulation pipe. The circulating hot air blows in from the middle of the upper and lower layers of each conveyor belt, passes through the upper layer of the conveyor belt and contacts the tea leaves, and then returns to the other end of the electric hot air blower through the circulation pipe from the other end. In this way, the moisture on the surface of the tea leaves is taken away, achieving low-temperature drying of the tea leaves.

[0013] In order to ensure that the drying air is more uniform in the box, a guide plate is also installed in the middle of each conveyor belt of the drying box. The guide plate is tilted upward from the air inlet side to the air outlet side to guide the hot air upward, so that it can cooperate well with the air balancing plate to improve the utilization rate of the hot air and make the tea leaves more evenly baked with hot air. The controllable air balancing mechanism includes several air balancing plates that can be rotated up or down, which are installed in sections at the bottom of the upper layer of each conveyor belt. By rotating the electric adjustment angle between the air balancing plate and the conveyor belt, the air volume entering each section of the conveyor belt can be controlled. In this way, the temperature and humidity indicators in different sections can be monitored. If there is a deviation in the temperature and humidity in each section on the same transverse section, it means that the environmental conditions of the tea materials at different transverse positions at the same length position on the conveyor belt are different, which will result in different degrees of drying of the entire batch of materials. Based on this, the system can adjust the air volume of each section, and adjust the environmental conditions of the entire conveyor belt to be close to equal by adjusting the air intake differences of each section, so as to achieve a uniform drying effect on the material, improve the uniformity and accuracy of low-temperature drying, make the drying degree of the discharged material close to the same, and achieve a high-precision standardized drying effect.

[0014] In addition, the temperature and humidity sensor modules are installed in each section corresponding to each layer of the conveyor belt in a multi-group configuration to obtain real-time data on temperature and humidity in the local area of ​​the drying box. These data can be used by the main control module to realize dynamic monitoring and regulation of the drying process. The main control module is connected to each mechanism and the sensor module to obtain the operating status, operating parameters and feedback data of the sensor module of each mechanism, and can control the start and stop of each mechanism, adjust the operating parameters, and regulate the air balancing plate under each layer of the conveyor belt. The main control module can control the angle of the air balancing plate according to the data collected in real time by the temperature and humidity sensor, so that the temperature and humidity data in the same layer are as equal as possible, thereby achieving a better low-temperature drying effect.

[0015] Beneficial technical effects of the present invention:

[0016] (I) Maintaining the quality and nutritional content of tea: The use of photoelectric combined heating method, combined with the continuous low-temperature tea drying process, can achieve rapid and uniform drying of tea at a lower temperature, effectively retaining the original quality of tea. This new technology can effectively reduce the loss of tea during the drying process. Traditional high-temperature drying methods may cause tea to change color, break or lose its natural aroma, while the photoelectric combined heating method can reduce these adverse effects and reduce the scrap rate.

[0017] (II) Automated and efficient drying control: Compared with the traditional single heating method, the photoelectric combined heating method has higher heating efficiency and energy utilization, which can reduce energy consumption and emissions. The system uses a multi-layer conveyor belt with gaps or meshes, and the tea material can automatically fall onto the lower conveyor belt, which can realize the fixed-point whole box drying of the material, and can also realize the continuous drying of the tea while feeding and discharging, so as to achieve efficient drying of batch tea. It can be operated and controlled by touch screen or computer program. Users can set different process parameters according to their needs to achieve precise control of the tea drying process. The photoelectric combined heating method can be precisely controlled according to the type and humidity level of tea, allowing tea producers to adjust the production process according to market demand. This flexibility can help meet the requirements of different markets. The automatic control system and continuous production method reduce the need for manual intervention and reduce labor costs on the production line. This helps to improve production efficiency and reduce production costs.

[0018] (III) Uniform drying effect with controllable quality: The equipment is equipped with single-zone quality detection technology that is differentiated by section. It can monitor and provide real-time feedback on the environmental conditions of tea materials in different sections on the conveyor belt. Based on the feedback detection results, it can adjust the parameters of the photoelectric combined heating device, the movement speed of the conveyor belt, etc., as well as the opening and closing angles of the wind equalizing plates to change the air intake volume in different sections, so as to ensure that the tea in each section is processed under uniform drying conditions as much as possible. For the continuous drying system, when transferring materials between conveyor belts, the material can be turned over smoothly, and the material originally at the bottom layer on the upper conveyor belt can be turned over to become the top layer on the lower conveyor belt, realizing automatic turning of the material with a high degree of turning completion, thereby obtaining homogenized and standardized tea.

[0019] (IV) Good system scalability: The equipment can be equipped with different auxiliary equipment and functional modules as needed, such as dehumidification devices, refrigeration devices, ventilation devices, etc., to meet the needs and usage conditions of different users. It can be seen that the tea low-temperature drying process and system of the photoelectric combined heating method of the present invention has the advantages of high efficiency, energy saving, automation, continuous production, quality detection and control, safety and reliability, and flexibility, which can meet the different needs of tea low-temperature drying and provide a new solution for tea production. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A three-dimensional diagram of a tea low-temperature drying system using a photoelectric combined heating method according to the present invention;

[0021] Figure 2 This is a structural side view of a tea low-temperature drying system using a photoelectric combined heating method according to the present invention;

[0022] Figure 3 This is a structural front view of a tea low-temperature drying system using a photoelectric combined heating method according to the present invention;

[0023] Figure 4 A three-dimensional diagram of the internal structure of a tea low-temperature drying system using a photoelectric combined heating method according to the present invention;

[0024] Figure 5 It is a schematic diagram of the structural principle of the first material equalizing device;

[0025] Figure 6 This is a schematic diagram of the limited material paving structure of the first material balancing device;

[0026] Figure 7 It is a structural diagram of the lifting control and rotation control of another structural form of the first turning roller;

[0027] Figure 8 The schematic diagram of the structure of the air balancing plate regulating the drying hot air section;

[0028] Fig. 9 A three-dimensional schematic diagram of a tea low-temperature drying system using a continuous drying mode;

[0029] Fig.10 A structural side view of a tea low-temperature drying system using a continuous drying mode;

[0030] Fig.11 A schematic diagram of the structure for adding a turning guide mechanism;

[0031] Fig.12 It is a schematic diagram of the principle process of the flipping guide mechanism;

[0032] Among them: 1-drying box, 2-conveyor belt, 3-air distribution plate, 4-circulation pipeline, 5-electric heating fan, 6-temperature and humidity sensor, 7-guide plate, 8-lamp holder, 9-lamp tube, 10-rotating motor, 11-first track, 12-first turning roller, 13-raking nail, 14-second track, 15-second turning roller, 16-guiding arc surface mechanism, 17-power guide belt. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0034] Embodiment 1:

[0035] A tea low temperature drying system using a photoelectric combined heating method, such as Figure 1-Figure 3 As shown:

[0036] The drying box 1 is provided with a feed inlet and a discharge outlet, and serves as the entire silo device of the system.

[0037] The conveying mechanism is a plurality of conveyor belts 2 with gaps or meshes arranged and installed one above the other, and is arranged in the drying box 1, and is used to carry and convey tea materials to be dried at low temperature, and can be transferred from the upper conveyor belt 2 to the lower conveyor belt 2 to achieve single batch or continuous material drying;

[0038] The controllable air distribution mechanism includes a plurality of air distribution plates 3 that can be rotated up or down, which are installed in sections at the bottom of the upper layer of each conveyor belt 2. The air volume entering each section of the conveyor belt 2 can be controlled by electrically adjusting the angle between the air distribution plates 3 and the conveyor belt 2; as long as the air volume at the air inlet is constant, the air volume entering the single-layer conveyor belt 2 remains constant for a certain period of time. Therefore, with the multi-section air distribution plates 3, the air volume entering each section can be changed, thereby changing the air volume in different sections through drying air, thereby controlling the materials in each section to obtain a relatively balanced and equal drying air volume, thereby achieving the purpose and effect of homogenization processing;

[0039] The sunlight-simulating light source mechanism is a multi-layer light source component, which is installed above each layer of the conveyor belt 2 to simulate sunlight. The irradiation light covers the entire conveyor belt 2, and the light intensity of the light source component is adjustable. LED lamp tubes 9 can be selected as lighting facilities, which have parameters and conditions such as the light intensity, spectrum, and color temperature of simulated sunlight. The light source component includes a lamp tube 9 and a lamp holder 8. The lamp holder 8 is suspended on the two opposite sides of the drying box 1. The lamp tube 9 is installed below the lamp holder 8, covering the upper surface of the entire conveyor belt 2.

[0040] The sensor module includes a temperature and humidity sensor 6, which is installed in each section corresponding to each layer of the conveyor belt 2 in a multi-group configuration to obtain real-time temperature and humidity data of the local area in the drying box 1; the temperature and humidity sensors 6 of each layer are installed away from the feed end of the conveyor belt 2; the number and position of each group of temperature and humidity sensors 6 correspond to the number and position of sections divided by the air equalizing plate 3 into which the conveyor belt 2 is divided, and are installed on the same row of lamp racks 8 parallel to the transverse direction of the conveyor belt 2; the air equalizing plate 3 is installed along the length direction of the conveyor belt 2, dividing the conveyor belt 2 into several sections along the length direction of the conveyor belt 2; the rotation angle information of the rotating motor 10 of each group of air equalizing plates 3 can be obtained and controlled by the main control module.

[0041] The low-temperature drying mechanism is used to dry the material inside the drying box 1, and includes a circulation pipe 4 and an electric hot air blower 5. The electric hot air blower 5 is connected to the drying box 1 through the circulation pipe 4, and can blow circulating hot air from the middle of each layer of the conveyor belt 2, pass through the upper layer of the conveyor belt 2, and then contact the material and then be connected back to the other end of the electric hot air blower 5 through the circulation pipe 4 from the other end; the temperature and power of the electric hot air blower 5 are controllable;

[0042] The main control module is connected to each mechanism and sensor module, and is used to obtain the operating status, operating parameters and feedback data of each mechanism, and can control the start and stop of each mechanism, adjust the operating parameters, and regulate the air distribution plate 3 under each layer of the conveyor belt 2.

[0043] Preferably, a guide plate 7 is provided in the middle of each layer of the conveyor belt 2, and the guide plate 7 is inclined upward from the air inlet side to the air outlet side, and the guide plate 7 is used to guide the hot air upward; the air equalizing plates 3 are arranged along the width direction of the conveyor belt 2, in the form of 3-6 pieces. In this embodiment, 4 pieces are taken as an example, and they are arranged in sequence and installed on the bottom surface of the upper layer of the conveyor belt 2; the side of the air equalizing plate 3 close to the air outlet is a hinged side, and the side close to the air inlet is a rotating side. Each air equalizing plate 3 is controlled by an independent rotating motor 10, which can control the angle between the rotating edge and the upper surface of the conveyor belt 2.

[0044] Preferably, the main control module obtains the temperature and humidity data of each layer and the inclination data of each air equalizing plate 3, and can adjust the temperature and humidity values ​​corresponding to the air equalizing plate 3 by adjusting the angle control of each air equalizing plate 3; wherein the temperature value is directly proportional to the inclination angle of the air equalizing plate 3, and the humidity value is inversely proportional to the inclination angle of the air equalizing plate. The main control module adjusts the inclination angle value of the air equalizing plate 3 by alternately detecting the temperature value and the humidity value, so that the temperature and humidity data in the same layer are as equal as possible. Since the dry hot air directly contacts the material after passing through the upper layer of the conveyor belt 2, it can take away the moisture of the material and increase its temperature. If the moisture content of the material is high or the stacking density is different, the moisture content and temperature of the hot air above the area will change. For example, if the material density is high and the moisture content is high, the value detected by the temperature and humidity sensor 6 above the area will change. The temperature value drops by 0.2-1.5 degrees, which is a significant difference. The humidity increases by 0.2-2, which is also a significant difference. The sensors of each section are concentrated in a horizontal arrangement and set at the end of the conveyor belt 2. Since there will be a height limit for the material roller after feeding, the material on the entire conveyor belt 2 is usually of the same density and thickness in the length direction. Therefore, the parameters detected by the temperature and humidity sensor 6 can represent the processing capacity of the conveyor belt 2 in a certain sense, and can be adjusted according to the value to ensure that the material in the front section of the conveyor belt 2 can be corrected in time. The air intake of each section is changed by the wind plate 3 to achieve overall balance as much as possible and control the degree of drying to be consistent. According to the size of the on-site equipment, multiple sets of sensor arrangements can be set.

[0045] When the conveying mechanism is a single batch conveyor, such as Figure 4-Figure 7 As shown, the conveyor belt 2 rotates continuously, and when the single batch of materials is evenly laid to the end of the bottom conveyor belt 2, the entire conveying mechanism stops running; a material equalizing device is installed above each layer of conveyor belt 2 along the length direction, wherein the top conveyor belt 2 is installed with a first material equalizing device, and the conveyor belts 2 of the remaining layers are installed with a second material equalizing device;

[0046] The first material leveling device includes: a first track 11, which is arranged on the inner wall of the drying box 1 above the top conveyor belt 2; a first turning roller 12, on which a rake nail 13 is provided, and the first turning roller 12 is configured to move along the first track 11; the first turning roller 12 is configured to be able to rise and fall in the vertical direction, and the lifting structure is realized by arranging a lifting module at the track mounting end, and the lifting module can be an electric push rod or a gear or a spiral lifting mechanism driven by the rotation of a motor; the lifting is used to adjust the gap height between the first turning roller 12 and the belt surface of the conveyor belt 2, which is used for controlling and adjusting the thickness of the material when the tea leaves enter the conveyor belt 2; the first turning roller 12 can also roll back and forth on the conveyor belt 2 along the first track 11 in the length direction, that is, move back and forth along the first track 11, and can be driven to move by the action of a walking motor or a rotating spiral rod and the wheel seats at both ends of the first turning roller 12;

[0047] The second material balancing device comprises: a second track 14, which is arranged on the inner wall of the drying box 1 along the length direction above the conveyor belt 2; a second material turning roller 15, on which a rake nail 13 is arranged, and the second material turning roller 15 moves along the second track 14 through a second walking mechanism. Compared with the first material balancing roller, the second material balancing roller has no lifting function; it only has the function of moving back and forth; further, a rolling motor connected to the shaft of the first and second material balancing rollers can be configured to drive them to roll during the movement.

[0048] In another embodiment of continuous drying: Figure 9-12As shown, the conveying mechanism is continuous conveying, the conveyor belt 2 rotates continuously, the uppermost conveyor belt 2 is used for feeding, and the lowermost conveyor belt 2 is used for discharging after drying. The tea material can be continuously transferred from high to low between each layer of the conveyor belt 2, and the rotation speed of each layer of the conveyor belt 2 is set to the time length from feeding to discharging, which can meet the drying process requirements of the material; at the end of each group of upper conveyor belts 2 transferring materials to the lower conveyor belt 2, a turning guide mechanism is installed, which can switch the upper and lower layers of the material; the turning guide mechanism includes a smooth guiding arc mechanism 16, which is installed on the wall of the drying box 1, located at the end of the upper conveyor belt 2 and the lower conveyor belt 2 transferring materials, and the spacing between the upper conveyor belt 2 is maintained to be not less than the thickness of the material, and a power guide belt 17 is installed between the end of the guiding arc mechanism 16 and the lower conveyor belt 2, and the power guide belt 17 is connected to the lower conveyor belt 2 obliquely downward, and the rotation direction is the same as the conveying direction of the lower conveyor belt 2, which is used to provide power to prevent material jamming during the material turning process. In the continuous drying equipment box, another process of low-temperature drying is sunlight exposure. Traditional sun drying also requires turning over the materials at a specific time so that the tea materials at the bottom can also be exposed to sunlight. Similarly, in the continuous conveying dryer, the light source comes from the lamp above the conveyor belt 2. If the thickness of the material is thicker, the tea leaves at the bottom cannot be exposed to the light source, and there will be problems of uneven low-temperature drying quality. If the thickness of the material is thinner, it will cause low efficiency and excessive energy and time costs. The purpose of setting the turning guide mechanism is to prevent the tea leaves from falling freely and randomly when they are about to fall to the lower conveyor belt 2, but first The material enters the guide arc mechanism 16 of the turning guide mechanism, and under the guidance of its arc shape, its own gravity, and the action of the upper conveyor belt 2, the material begins to turn along the guide arc mechanism 16. After turning to a certain extent, the lower tea material is separated from the contact of the upper conveyor belt 2. In order to prevent the material from getting stuck, the original upper tea material contacts the power guide belt 17 to provide power, and continues to move forward with the original lower tea material and finally falls on the lower conveyor belt 2, thereby achieving orderly turning over. The tea material that was originally insufficiently illuminated can obtain sufficient light source irradiation on the lower conveyor belt 2. If the conveyor belt 2 is an even number of layers, the material is more uniform. The problem of achieving smooth and natural turning over and conveying without physical contact to create crushing is solved, and the overall low-temperature drying quality uniformity is improved.

[0049] Example 2: Drying process of a tea low temperature drying system

[0050] The tea material to be dried is pre-treated to remove impurities and adjust the humidity to ensure that the tea is suitable for entering the low-temperature drying system; the conveying mechanism, controllable air distribution mechanism, light source mechanism, low-temperature drying mechanism, sensor module and main control module of the drying box 1 are started and standby, and the material enters from the feed port of the drying box 1, falls on the belt surface of the top conveyor belt 2, and passes through multiple layers of conveyor belts 2 in sequence and finally falls on the bottom conveyor belt 2, and is discharged from the discharge port of the drying box 1;

[0051] Among them: the dry hot air enters the middle area of ​​each layer of conveyor belt 2 through the circulation pipe 4, and then passes through the upper layer of the conveyor belt 2 to contact the material, heats the material temperature and takes away the moisture of the material, and finally the air is discharged from the air outlet of the conveyor belt 2 of this layer for collection, and then enters the low-temperature drying mechanism, and the cycle is repeated;

[0052] During the drying process, in order to ensure the uniformity of the drying of the tea leaves, the angle between the air distribution plate 3 and the conveyor belt 2 can be adjusted to control the air volume in each section, so as to adjust the distribution of the drying air and ensure the uniformity of the tea leaves during the drying process.

[0053] Wherein: for each section of each layer of conveyor belt 2, the detection data of temperature and humidity sensor 6 controls the rotating motor 10 of air balancing plate 3, and adjusts the angle of air balancing plate 3 to achieve the ideal value of temperature and humidity in each section; and the light source component above each layer of conveyor belt 2 starts to simulate sunlight, and the irradiation light covers the entire conveyor belt 2, and the light intensity can be adjusted as needed;

[0054] When single batch drying is carried out, when the single batch of materials is evenly laid and reaches the end of the bottom conveyor belt 2, the entire conveying mechanism stops running and the low-temperature drying process is started again; and each layer of tea materials can be intermittently turned over by the turning roller to ensure the uniformity of material drying and light exposure;

[0055] When the conveying mechanism is in continuous conveying, the conveyor belt 2 rotates continuously, the uppermost conveyor belt 2 is used for feeding, and the lowermost conveyor belt 2 is used for discharging after drying. The tea material can be continuously transferred from high to low between each layer of the conveyor belt 2, and the rotation speed of each layer of the conveyor belt 2 is set to the time from feeding to discharging, which can meet the drying process requirements of the material; and when the material falls from the upper layer of the conveyor belt 2 and enters the lower layer of the conveyor belt 2, the upper and lower layers of the material can be swapped and turned over through the turning guide mechanism to ensure the uniformity of material drying and illumination.

[0056] It should be noted that the turning guide mechanism, the powered guide belt 17, can provide power to the material along its rotation direction during the turning process, and the linear speed matches the conveying speed of the upper conveyor belt 2 and is the same as the conveying direction of the lower conveyor belt 2 to avoid material jamming during the turning process.

[0057] Preferably, during the drying process, the temperature and humidity data of each layer and the inclination data of each air balancing plate 3 are obtained, and the temperature and humidity values ​​corresponding to the air balancing plate 3 are adjusted by adjusting the angle control of each air balancing plate 3; based on the fact that the temperature value is proportional to the inclination angle of the air balancing plate 3, and the humidity value is inversely proportional to the inclination angle of the air balancing plate 3, the inclination angle value of the air balancing plate 3 is adjusted by alternately detecting the temperature value and the humidity value, so that the temperature and humidity data in the same layer tend to be as equal as possible. The specific operations are as follows:

[0058] In the temperature value detection task, the temperature values ​​of all temperature and humidity sensors 6 are obtained, and the maximum temperature value, minimum temperature value and average temperature value are obtained therefrom, and it is determined whether the absolute value of the difference between the maximum temperature value, the minimum temperature value and the average temperature value exceeds the threshold value. If exceeded, the one with the larger absolute value is taken for adjustment. If the absolute value of the maximum temperature is large, it means that the drying wind in the section where the temperature and humidity sensor 6 is located is too large. The main control module controls the rotating motor 10 of the wind equalizing plate 3 corresponding to the section to reduce the angle by several units, otherwise, it increases the angle by several units. After one detection unit time, the temperature value continues to be detected, and feedback adjustment is made. After N detection unit time, it switches to the humidity detection task. The technical principle is that by adjusting and controlling the air volume of the drying hot air, the air volume delivery in the entire drying process can be guaranteed to be in a flexible and active state. It is not a traditional air duct design. The air flow in the box is fixed. Flexible and dynamic air volume adjustment can It is enough to make the air volume in the entire drying box 1 evenly distributed for the material. The area where the tea leaves are more humid or the tea leaves with lower temperature are located has relatively more air volume. Similarly, in the humidity detection task, the humidity values ​​in all temperature and humidity sensors 6 are obtained, and the maximum humidity value, the minimum humidity value and the average humidity value are obtained therefrom, and it is determined whether the absolute value of the difference between the maximum humidity value and the minimum humidity value and the average humidity value exceeds the threshold value. If it exceeds, the one with the larger absolute value is adjusted. If the absolute value of the maximum humidity is large, it means that the drying wind in the section where the temperature and humidity sensor 6 is located is too small. The main control module controls the rotating motor 10 of the wind equalizing plate 3 corresponding to the section to increase the unit angle. Otherwise, it reduces the unit angles. After one detection unit time, the humidity value continues to be detected and feedback adjustment is made until N detection unit times have passed, and then the temperature detection task is switched to, and the temperature detection task and the humidity detection task are continuously and alternately performed. This alternating process can ensure that both temperature and humidity data are taken into account during the drying process, and the inward air volume is always kept in dynamic adjustment, thereby obtaining hot air drying products with stronger targeting and better uniformity.

[0059] It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, and do not constitute a limitation of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the appended claims, or the equivalent forms of such scope and boundaries.

Claims

1. A tea low temperature drying system with photoelectric combined heating method, characterized in that include: The drying box (1) is provided with a feed inlet and a discharge outlet and serves as the entire silo device of the system. The conveying mechanism is a plurality of conveyor belts (2) with gaps or meshes arranged and installed one above the other, and is arranged in the drying box (1) for carrying and conveying tea materials to be dried at low temperature, and can be transferred from the upper conveyor belt (2) to the lower conveyor belt (2) to achieve single batch or continuous material drying; The controllable air distribution mechanism comprises a plurality of air distribution plates (3) that can be rotated up or down and are installed in sections at the bottom of the upper layer of each conveyor belt (2). The air volume entering each section of the conveyor belt (2) can be controlled by electrically adjusting the angle between the air distribution plates (3) and the conveyor belt (2); The sunlight-simulating light source mechanism is a multi-layer light source component, which is respectively installed above each layer of the conveyor belt (2) and is used to simulate sunlight irradiation, so that the irradiation light covers the entire conveyor belt (2), and the light intensity of the light source component is adjustable; The low-temperature drying mechanism is used to dry the material inside the drying box (1), and comprises a circulation pipe (4) and an electric hot air blower (5). The electric hot air blower (5) is connected to the drying box (1) through the circulation pipe (4) and can blow circulating hot air from the middle of each layer of the conveyor belt (2). After passing through the upper layer of the conveyor belt (2) and contacting the material, the circulating hot air is returned to the other end of the electric hot air blower (5) through the circulation pipe (4) from the other end; The sensor module includes a temperature and humidity sensor (6), which is installed in each section corresponding to each layer of the conveyor belt (2) in a plurality of groups, and is used to obtain real-time data on temperature, humidity, wind volume and wind speed in a local area of ​​the drying box (1); The main control module is connected to each mechanism and the sensor module, and is used to obtain the operating status and operating parameters of each mechanism and the feedback data of the sensor module, and can control the start and stop of each mechanism, adjust the operating parameters, and regulate the air distribution plate (3) under each layer of the conveyor belt (2).

2. The tea low-temperature drying system with photoelectric combined heating method according to claim 1 is characterized in that: A guide plate (7) is provided in the middle of each layer of the conveyor belt (2), and the guide plate (7) is inclined upward from the air inlet side to the air outlet side, and the guide plate (7) is used to guide the hot air upward; The air balancing plates (3) are arranged along the width direction of the conveyor belt (2), and are arranged in 3 to 6 pieces in sequence and equidistantly installed on the lower part of the upper layer of the conveyor belt (2) and the upper part of the guide plate (7); the side of the air balancing plates (3) close to the air outlet is a hinged side, and the side close to the air inlet is a rotating side. Each air balancing plate (3) is controlled by an independent rotating motor (10), and the angle between the rotating side and the upper layer of the conveyor belt (2) can be controlled.

3. The tea low-temperature drying system with photoelectric combined heating method according to claim 2 is characterized in that: The light source component comprises a lamp tube (9) and a lamp holder (8); the lamp holder (8) is suspended on two opposite sides of the drying box (1); the lamp tube (9) is installed below the lamp holder (8) and directly faces the upper surface of the conveyor belt (2); The temperature and humidity sensors (6) of each layer are installed at a position away from the feed end of the conveyor belt (2); the number and position of each group of temperature and humidity sensors (6) correspond to the number and position of the sections into which the conveyor belt (2) is divided by the air distribution plate (3), and are installed on the same row of light racks (8) parallel to the transverse direction of the conveyor belt (2); The air distribution plate (3) is installed along the length direction of the conveyor belt (2), and divides the conveyor belt (2) into a plurality of sections along the length direction of the conveyor belt (2); The rotation angle information of the rotating motor (10) of each set of air balancing plates (3) can be acquired and controlled by the main control module.

4. The tea low-temperature drying system with photoelectric combined heating method according to claim 3 is characterized in that: The main control module obtains the temperature and humidity data of each layer and the inclination angle data of each air balancing plate (3), and can adjust the temperature and humidity values ​​corresponding to each air balancing plate (3) by controlling and adjusting the angle of each air balancing plate (3); The temperature value is directly proportional to the inclination angle of the air balancing plate (3), and the humidity value is inversely proportional to the inclination angle of the air balancing plate. The main control module adjusts the inclination angle of the air balancing plate (3) by alternately detecting the temperature value and the humidity value, so that the temperature and humidity data in the same layer tend to be as equal as possible.

5. The tea low-temperature drying system with photoelectric combined heating method according to claim 1 is characterized in that: When the conveying mechanism is in single-batch conveying, the conveyor belt (2) rotates continuously, and when the single-batch material is evenly laid to the end of the bottom conveyor belt (2), the entire conveying mechanism stops running; A material balancing device is installed above each layer of conveyor belt (2) along the length direction, wherein the topmost layer of conveyor belt (2) is installed with a first material balancing device, and the remaining layers of conveyor belts (2) are installed with a second material balancing device; The first material equalizing device comprises: A first track (11) is arranged on the inner wall of the drying box (1) above the top conveyor belt (2); a first material turning roller (12) on which a rake nail (13) is provided, and the first material turning roller (12) is configured to be movable along a first track (11); the first material turning roller (12) is configured to be able to rise and fall in a vertical direction, and to adjust the gap height between the first material turning roller (12) and the conveyor belt (2) surface, so as to control and adjust the thickness of the tea leaves when they enter the conveyor belt (2); the first material turning roller (12) can also roll back and forth on the conveyor belt (2) along the first track (11) in the length direction; The second material balancing device comprises: A second track (14) is arranged above the conveyor belt (2) and on the inner wall of the drying box (1) along the length direction; A second material turning roller (15) is provided with a rake nail (13), and the second material turning roller (15) moves along a second track (14) through a second walking mechanism.

6. The tea low-temperature drying system with photoelectric combined heating method according to claim 1 is characterized in that: When the conveying mechanism is in continuous conveying mode, the conveyor belt (2) rotates continuously, the uppermost conveyor belt (2) is used for feeding, and the lowermost conveyor belt (2) is used for discharging after drying. The tea material can be continuously transferred from high to low between the conveyor belts (2) at each layer, and the rotation speed of each conveyor belt (2) is set to the time length from feeding to discharging, which can meet the material drying process requirements; At the end of each group of upper conveyor belts (2) transferring materials to the lower conveyor belts (2), a turning guide mechanism is installed to switch and turn over the upper and lower layers of the materials; The flipping guide mechanism comprises a smooth guiding camber mechanism (16), which is installed on the wall of the drying box (1) and is located at the end of the upper conveyor belt (2) and the lower conveyor belt (2) for transferring materials, and the distance between the upper conveyor belt (2) and the upper conveyor belt (2) is maintained to be not less than the thickness of the materials. A power guiding belt (17) is installed between the end of the guiding camber mechanism (16) and the lower conveyor belt (2). The power guiding belt (17) is connected to the lower conveyor belt (2) obliquely downward, and the rotation direction is the same as the conveying direction of the lower conveyor belt (2), and is used to provide power to prevent the materials from getting stuck during the flipping process of the materials.

7. A drying process based on the tea low temperature drying system according to any one of claims 1 to 6, characterized in that The following steps are involved: The tea material to be dried is pre-treated to remove impurities and adjust the humidity to ensure that the tea is suitable for entering the low-temperature drying system; the conveying mechanism, controllable air distribution mechanism, light source mechanism, low-temperature drying mechanism, sensor module and main control module of the drying box (1) are started and put into standby mode, and the material enters from the feed port of the drying box (1), falls onto the surface of the uppermost conveyor belt (2), passes through multiple layers of conveyor belts (2) in sequence, and finally falls onto the lowermost conveyor belt (2), and is discharged from the discharge port of the drying box (1); Wherein: the drying hot air enters the area between the upper and lower layers of each conveyor belt (2) from one side of the drying box (1) through the circulation pipe (4), then passes through the upper layer of the conveyor belt (2) to contact the material, heats the material to increase the temperature and removes the evaporated moisture of the material, and finally discharges from the air outlet of the conveyor belt (2) on the other side of the drying box (1) for collection, and then enters the low-temperature drying mechanism, thus circulating; During the drying process, in order to ensure the uniformity of the drying of the tea leaves, the angle between the air distribution plate (3) and the conveyor belt (2) can be adjusted to control the air volume in each section, so as to adjust the distribution of the drying air to ensure the uniformity of the tea leaves during the drying process. Wherein: for each section of each conveyor belt (2), the detection data of the temperature and humidity sensor (6) controls the rotating motor (10) of the air distribution plate (3) to adjust the angle of the air distribution plate (3) to achieve the ideal value of temperature and humidity in each section; and the light source component above each conveyor belt (2) starts to simulate sunlight, and the irradiation light covers the entire conveyor belt (2), and the light intensity can be adjusted as needed; When single batch drying is carried out, when the single batch of materials is evenly laid and reaches the end of the bottom conveyor belt (2), the entire conveying mechanism stops running and the low-temperature drying process is started again; and each layer of tea materials can be intermittently turned by the turning roller to ensure the uniformity of material drying and light exposure; When batch continuous drying is carried out, the conveyor belt (2) rotates continuously, the uppermost conveyor belt (2) is used for feeding, and the lowermost conveyor belt (2) is used for discharging after drying. The tea material can be continuously transferred from high to low between the conveyor belts (2) on each layer, and the rotation speed of each conveyor belt (2) is set to the time from feeding to discharging, which can meet the drying process requirements of the material; and when the material falls from the upper conveyor belt (2) to the lower conveyor belt (2), the upper and lower layers of the material can be switched and flipped through the flipping guide mechanism to ensure the uniformity of material drying and illumination.

8. A drying process according to claim 7, characterized in that: The turning guide mechanism, with a powered power guide belt (17), can provide power to the material in its rotation direction during the turning process, and the linear speed matches the conveying speed of the upper conveyor belt (2) and is the same as the conveying direction of the lower conveyor belt (2), so as to avoid material jamming during the turning process.

9. A drying process according to claim 7, characterized in that: During the drying process, the temperature and humidity data of each layer and the inclination data of each air balancing plate (3) are obtained, and the temperature and humidity values ​​corresponding to each air balancing plate (3) are adjusted by controlling and adjusting the angle of each air balancing plate (3); based on the fact that the temperature value is proportional to the inclination angle of the air balancing plate (3), and the humidity value is inversely proportional to the inclination angle of the air balancing plate, the inclination angle value of the air balancing plate (3) is adjusted by alternately detecting the temperature value and the humidity value, so that the temperature and humidity data in the same layer tend to be as equal as possible.

10. A drying process according to claim 9, characterized in that: In the temperature value detection task, the temperature values ​​of all temperature and humidity sensors (6) are obtained, and the maximum temperature value, the minimum temperature value and the average temperature value are obtained therefrom, and it is determined whether the absolute value of the difference between the maximum temperature value, the minimum temperature value and the average temperature value exceeds the threshold value. If it exceeds, the one with the larger absolute value is adjusted. If the absolute value of the maximum temperature is large, it means that the dry wind in the section where the temperature and humidity sensor (6) is located is too large. The main control module controls the rotating motor (10) of the wind plate (3) corresponding to the section to rotate to reduce a certain unit angle. Otherwise, it increases a certain unit angle. After one detection unit time, the temperature value is continuously detected and feedback adjustment is made until N detection unit times have passed, and then the task of humidity detection is switched to. In the humidity detection task, the humidity values ​​of all temperature and humidity sensors (6) are obtained, and the maximum humidity value, the minimum humidity value and the average humidity value are obtained therefrom, and it is determined whether the absolute value of the difference between the maximum humidity value, the minimum humidity value and the average humidity value exceeds the threshold value. If it exceeds, the one with the larger absolute value is adjusted. If the absolute value of the maximum humidity is large, it means that the dry wind in the section where the temperature and humidity sensor (6) is located is too small. The main control module controls the rotating motor (10) of the wind plate (3) corresponding to the section to increase the rotation by a number of unit angles. Otherwise, it reduces the number of unit angles. After one detection unit time, the humidity value continues to be detected and feedback adjustment is made. After N detection unit times, it switches to the temperature detection task, and the temperature detection task and the humidity detection task are continuously and alternately performed.

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