Dynamic indoor static withering system

Abstract

This invention provides a dynamic indoor static withering system for tea processing, installed in a withering chamber. The walls of the withering chamber have a plurality of ventilation openings. The system includes: a humidity detector that detects the indoor humidity of the withering chamber and outputs a humidity value; a PLC controller electrically connected to the humidity detector, which receives and compares the humidity value, and outputs a first control signal when the comparison determines that the humidity value falls within a first humidity range; and at least one exhaust fan electrically connected to the PLC controller. The exhaust fan receives and operates at speed A for X minutes according to the first control signal, then decelerates to speed B for Y minutes, and repeats the cycle between speed A and speed B until the tea oxidation process is completed.

Description

[Technical Field]

[0001] This invention relates to tea withering equipment, and in particular to a dynamic indoor static withering system. [Previous Technology]

[0002] Withering is a crucial step in tea processing, its effectiveness impacting the final quality and flavor of the tea. Traditionally, tea production relies heavily on natural environmental conditions; that is, withering rooms lack air conditioning, allowing the tea leaves to lose moisture entirely through climate changes. Therefore, tea produced in sunny weather with humidity levels between 50-60% RH (Relative Humidity) yields better quality. However, unstable climate changes make it difficult to maintain consistent tea quality. Thus, the stability of the withering process is heavily influenced by weather variations, hindering quality control. To mitigate the impact of the environment on withering, some tea factories have added ventilation openings to the withering rooms to improve airflow and even moisture loss. However, because air intake and exhaust are not precisely controlled, temperature and humidity still fluctuate with changes in the natural environment, ultimately leading to inconsistent quality.

[0003] To further address the aforementioned issues, many tea factories have begun to adopt a constant temperature and humidity withering chamber 1, as shown in Figure 1. This chamber is equipped with at least one air conditioner 10, at least one dehumidifier 11, at least one humidifier 12, and at least one exhaust duct 13. The humidity and temperature within the withering chamber 1 are then controlled using programmed controllers or manual controls. This allows the tea to wither and ferment under stable conditions and at fixed temperature and humidity, thereby improving tea quality and yield. However, while this method seems to provide an ideal tea-making environment, the flow of moisture within the tea leaves involves three steps: water loss, water removal, and water retention. The coarse fibers in the tea stems and the fine fibers in the tea leaves have different moisture requirements and flow times. Therefore, when the temperature and humidity are excessively controlled, the moisture flow of these different fibers will be affected, potentially leading to insufficient oxidation and negative changes such as a stronger bitter taste, a raw or astringent flavor, poor aroma, and reduced smoothness of the tea soup. Furthermore, in order to fully control the indoor temperature and humidity, the aforementioned withering room 1 generally does not have ventilation openings or exhaust channels to avoid reducing the cooling efficiency. This will make it easy for the tea to lack sufficient oxygen during the fermentation process, which will affect the fermentation results. Tea that has not been fully fermented is prone to developing an unpleasant taste due to insufficient oxidation during storage, which may cause physical discomfort such as palpitations, gastrointestinal discomfort, or decreased sleep quality in drinkers. Not only does it still have quality problems, but it is also not conducive to the drinking experience satisfaction of drinkers.

[0004] Furthermore, to achieve the requirement of constant temperature and humidity control, the air conditioner 10, the dehumidifier 11, and the humidifier 12 inevitably need to operate for extended periods. For a 60-square-meter withering chamber 1, the simultaneous operation of these three devices would require approximately AC 220V / 50-75A of instantaneous power. If the withering process takes 11 hours, the power consumption and cost would be considerable, hindering not only cost reduction but also the current demands for environmental protection and energy conservation. Therefore, this invention aims to explore how to provide a tea processing environment that simultaneously provides stable temperature and humidity conditions, good ventilation, and sufficient oxygen, while considering the varying durations of moisture flow required by different fibers within the tea leaves. This would address the shortcomings of existing technologies and achieve energy conservation and carbon reduction. [Summary of the Invention]

[0005] In view of the above problems, the purpose of the present invention is to provide an indoor withering system that intelligently controls the indoor air flow and humidity by adjusting the exhaust fan speed according to the real-time ambient humidity, so as to ensure that the tea leaves are evenly exposed to air and avoid excessive or insufficient withering from affecting the quality of the tea leaves.

[0006] To achieve the above objectives, the present invention discloses a dynamic indoor static withering system, which is installed in a withering chamber for tea processing. The walls of the withering chamber are provided with a plurality of ventilation openings. The system includes: a humidity detector, which detects the indoor humidity of the withering chamber and outputs a humidity value; a PLC (Programmable Logic Controller), which is electrically connected to the humidity detector. The PLC controller receives and compares the humidity value, and outputs a first control signal when it is determined that the humidity value falls within a first humidity range; and at least one exhaust fan, which is electrically connected to the PLC controller. The exhaust fan receives and operates at speed A for X minutes according to the first control signal, then decelerates to speed B for Y minutes, and repeats the speed A and speed B cycles until the tea oxidation process is completed.

[0007] Wherein, the first humidity range is 70-75%RH (Relative Humidity). The exhaust fan operates at 1600 RPM (Revolutions Per Minute) for 2-3 minutes, outputting 2.5-2.7 m / s (meters per second), then automatically decelerates to 500 RPM for 6-8 minutes, outputting 0.8-1.0 m / s (meters per second). When the PLC controller determines that the humidity value falls within a second humidity range, it outputs a second control signal to make the exhaust fan operate at speed B. The second humidity range is 50-55%RH, and when the PLC controller determines that the humidity value falls within this second humidity range, it outputs the second control signal to make the exhaust fan operate at 500 RPM, ensuring that air in the indoor space circulates through the ventilation openings. The dynamic indoor static withering system includes at least one dehumidifier, which is electrically connected to the PLC controller. When the PLC controller compares and finds that the humidity value is greater than a working value, it drives the dehumidifier to dehumidify.

[0008] Furthermore, the dynamic indoor static withering system includes an air conditioner and a temperature detector. The air conditioner and the temperature detector are electrically connected to the PLC controller to maintain the temperature in the withering chamber between 15 and 28°C. The withering chamber is equipped with at least one exhaust duct, which is connected to the air conditioner to deliver the cold air output by the air conditioner to one location in the withering chamber. The dynamic indoor static withering system includes a withering rack, which is not completely sealed. The withering rack has a plurality of withering platforms arranged at horizontal intervals, making the withering rack appear to be divided into a plurality of airflow channels. Each airflow channel has a corresponding movable valve on one side. The withering rack is placed in the withering chamber to improve the uniformity of the tea leaves being blown by the airflow by carrying the tea leaves through each withering platform. The withering chamber is equipped with an isolation wall with an opening for mounting the withering shelves. This ensures that the front and rear openings of the airflow ducts of each withering platform are positioned on opposite sides of the isolation wall, further improving airflow control. The humidity value is a 4–20 mA digital signal.

[0009] In summary, the most fundamental aspect of this invention is that, through the humidity detector and the PLC controller, the operating status and time of the exhaust fan are automatically adjusted according to real-time environmental conditions to ensure that the humidity remains stable within the optimal range. Furthermore, this invention uses the first control signal to enable the exhaust fan to operate at precisely segmented wind speeds, employing a high-speed-low-speed alternating frequency conversion mode. This avoids excessively rapid or slow changes in moisture during the tea withering process. Moreover, the coordinated operation of the dehumidifier and the exhaust fan effectively ensures that the humidity in the withering room can be quickly reduced when it is too high, achieving intelligent control of the indoor environmental conditions. Thus, this invention integrates frequency conversion operation and intelligent environmental control technologies to reduce energy consumption, thereby saving electricity. The real-time power demand of the indoor static withering system can be significantly reduced to approximately AC 220V / 5-15A, thoroughly realizing the goal of energy conservation and carbon reduction.

[0010] Incidentally, it is worth mentioning that the present invention further utilizes the setting of the isolation wall and withering rack to improve the utilization of indoor air velocity, so that the same air volume can cover more tea leaves and reduce additional energy consumption and carbon emissions. Furthermore, it can be finely adjusted for the humidity requirements of different areas to avoid over-operation of the overall equipment, which is in line with the environmental protection trend and helps the tea industry move towards green production.

Implementation Method

[0011] To enable those skilled in the art to clearly understand the contents of this invention, please refer to the following description and accompanying drawings.

[0012] Please refer to Figures 2 and 3, which are respectively architectural diagrams and application diagrams of a preferred embodiment of the present invention. As shown in the figures, the dynamic indoor static withering system 2 is installed in a withering chamber 1 for tea processing. It includes a humidity detector 20, a PLC controller 22 and at least one exhaust fan 23. The PLC controller 22 is electrically connected to the humidity detector 20 and the exhaust fan 23. The walls of the withering chamber 1 are provided with a plurality of ventilation openings 14. These ventilation openings 14 can be opened on opposite sides of the walls of the withering chamber 1 to allow air intake and ventilation, thereby improving the airflow in the indoor space of the withering chamber 1 and improving the indoor oxygen content. The tea leaves to be processed can be placed on multiple tea leaves and then arranged in the withering chamber 1 through racks or shelves. At this time, the humidity detector 20 detects the indoor humidity of the withering chamber 1 and outputs a humidity value 200. The PLC controller 22 receives and compares the humidity value 200. When the comparison shows that the humidity value 200 falls within a first humidity range 220, it outputs a first control signal 221. The exhaust fan 23 receives the first control signal 221 and runs at speed A for X minutes, then decelerates to speed B for Y minutes, repeating the speed A and speed B cycles until the tea oxidation process is completed. In this way, the indoor static withering system 2 dynamically adjusts the speed and running time of the exhaust fan 23 to meet the different time requirements of the coarse and fine fibers in the tea for the water removal, water elimination, and water retention stages, thereby improving the tea withering effect and enhancing the quality of the tea.

[0013] Please refer to Figure 4, which is a schematic diagram of the application of three preferred embodiments of the present invention. As shown in the figure, the indoor static withering system 2 with dynamic humidity control is installed in a withering room 1 for tea processing. It includes a humidity detector 20, a temperature detector 21, a PLC controller 22, an exhaust fan 23, an air conditioner 10, at least one dehumidifier 11, and a withering shelf 24. The PLC controller 22 can be electrically connected to the humidity detector 20, the temperature detector 21, the exhaust fan 23, the air conditioner 10, and the dehumidifier 11 via wired or wireless means. The withering shelf 24 is a partially sealed withering shelf. The withering shelf has a plurality of withering platforms 240 arranged horizontally at intervals, which makes the withering shelf appear to be divided into a plurality of airflow channels. Each airflow channel has a corresponding movable valve 241 on one side, which can be opened or closed to further adjust the airflow direction. The withering chamber 1 is equipped with an isolation wall 15, which divides the withering chamber 1 into two spaces. A plurality of exhaust ducts 13 are installed on the top of the withering chamber 1, which are connected to the air conditioner 10 and the dehumidifier 11 to deliver the cool air and dry air output by the air conditioner 10 and the dehumidifier 11 to a point in the withering chamber 1 to improve the environmental stability. At least one ventilation opening 14 can be opened on each of the opposite side walls of the withering chamber 1, and each ventilation opening 14 is located on the opposite side of the isolation wall 15. The partition wall 15 has an insertion opening (not shown) for embedding the withering shelf 24. When the withering shelf 24 is embedded in the insertion opening and placed in the withering chamber 1, the front and rear openings of the airflow channels of each withering platform 240 fall on opposite sides of the partition wall 15. This improves the uniformity of airflow when tea leaves are carried by each withering platform 240, thereby further improving the airflow control effect.

[0014] The humidity detector 20 is installed in the withering chamber 1 to detect the indoor humidity of the withering chamber 1 and outputs a humidity value 200 as a 4-20mA digital signal to the PLC controller 22. Similarly, the temperature detector 21 is also installed in the withering chamber 1 to detect the indoor temperature of the withering chamber 1 and outputs a temperature value 210 to the PLC controller 22. When the PLC controller 22 receives and compares the humidity value 200, and finds that the humidity value 200 is greater than a working value, it drives the dehumidifier to dehumidify. When it finds that the humidity value 200 falls within a first humidity range 220, it outputs a first control signal 221, causing the exhaust fan 23 to receive and run at speed A for X minutes according to the first control signal 221, then decelerate to speed B for Y minutes, and repeat the speed A and speed B cycles until the tea oxidation process is completed. When the PLC controller 22 compares and finds that the humidity value 200 falls within a second humidity range 222, it outputs a second control signal 223 so that the exhaust fan 23 operates only at speed B.

[0015] For example, when the PLC controller 22 receives the humidity value 200 and compares it to find that the humidity value 200 is greater than 75%RH (Relative Humidity), it drives the dehumidifier 11 to run in order to dehumidify and stabilize the environmental conditions inside the withering chamber 1; and when the comparison finds that the humidity value 200 falls between 70% and 75%RH, the PLC controller 22 outputs the first control signal 221, causing the exhaust fan 23 to receive and operate at a speed of 1600RPM (Revolutions Per Minute) according to the first control signal 221. The fan operates at 2.5-2.7 m / s (meters per second) for 2-3 minutes, then automatically slows down to 500 RPM for 6-8 minutes, outputting 0.8-1.0 M / s. This repeated rotation at speeds A and B achieves the tea oxidation process, improving air circulation within the withering chamber, enhancing ventilation, and accelerating moisture removal. It also meets the different moisture flow times required for the coarse and fine fibers of the tea, effectively improving withering and fermentation results and ensuring high-quality tea production. When the PLC controller 22 detects that the humidity value 200 falls within the 50-55% RH range, it outputs a second control signal to keep the exhaust fan operating at a lower speed of 500 RPM, ensuring air circulation through the vents 14 without excessive dehumidification. At the same time, when the PLC controller 22 receives and compares the temperature value 210, it adjusts the output of the air conditioner 10 accordingly to ensure that the temperature inside the withering chamber 1 is between 15 and 28°C.

[0016] Thus, in this invention, when humidity is too high, a dehumidifier is first used to assist in regulation, quickly reducing the humidity to an acceptable slightly high level to avoid excessive moisture content in the tea leaves affecting the quality of the tea. Then, by increasing the speed of the exhaust fan 23 to accelerate airflow, the fan speed is intermittently reduced to accommodate the varying moisture flow time required by the tea fiber size, ensuring sufficient moisture flow time for all tea fibers and thoroughly achieving the desired effects of water removal and elimination. On the other hand, when humidity is low, the exhaust fan 23 operates at a low speed for air ducting. In other words, this invention uses a dynamic humidity control method with a 4-20mA signal to detect humidity in the air under constant temperature control, thus improving the problem of insufficient oxidation of tea leaves caused by the strict humidity and temperature control methods used in conventional constant temperature and humidity indoor withering techniques, which affect the moisture flow of different tea fibers. Furthermore, the present invention effectively reduces operating energy consumption due to the dynamic speed adjustment of the exhaust fan 23 and its linkage with the operating strategy of the dehumidifier 11. In addition, the exhaust duct 13 is designed to optimize airflow utilization, thereby reducing unnecessary energy loss and achieving the effect of energy saving and carbon reduction.

[0017] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention. Therefore, any equivalent changes and modifications made without departing from the spirit and scope of the invention should be covered within the patent scope of the present invention. The terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance. It should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. [Simplified Explanation of the Diagram]

[0018] Figure 1 is a schematic diagram of a conventional constant temperature and humidity withering chamber. Figure 2 is a structural diagram of a preferred embodiment of the present invention. Figure 3 is an application schematic diagram of a preferred embodiment of the present invention. Figure 4 is an application schematic diagram of a second preferred embodiment of the present invention.

Claims

1. A dynamic indoor static withering system, installed in a withering chamber for tea processing, the walls of the withering chamber having a plurality of ventilation openings, comprising: a humidity detector for detecting the indoor humidity of the withering chamber and outputting a humidity value; a PLC controller electrically connected to the humidity detector, the PLC controller receiving and comparing the humidity value, and outputting a first control signal when the comparison determines that the humidity value falls within a first humidity range; and at least one exhaust fan electrically connected to the PLC controller, the exhaust fan receiving and operating at speed A for X minutes according to the first control signal, then decelerating to speed B for Y minutes, thereby repeating the speed A and speed B cycles until the tea oxidation process is completed.

2. The dynamic indoor static withering system as described in claim 1, wherein, The first humidity range is 70-75%RH. The exhaust fan runs at 1600RPM for 2-3 minutes, outputting 2.5-2.7M / s airflow, and then automatically slows down to 500RPM for 6-8 minutes, outputting 0.8-1.0M / s airflow.

3. The dynamic indoor static withering system as described in claim 1, wherein, When the PLC controller determines that the humidity value falls within a second humidity range, it outputs a second control signal to make the exhaust fan operate at speed B.

4. The dynamic indoor static withering system as described in claim 3, wherein, The second humidity range is 50-55%RH. When the PLC controller compares and finds that the humidity value falls within the second humidity range, it outputs the second control signal to make the exhaust fan run at a speed of 500RPM to ensure that the air in the indoor space circulates through the ventilation openings.

5. The dynamic indoor static withering system as described in claim 1 includes at least one dehumidifier electrically connected to the PLC controller; when the PLC controller determines that the humidity value is greater than a working value, it drives the dehumidifier to dehumidify.

6. The dynamic indoor static withering system as described in claim 1 includes an air conditioner and a temperature detector, the air conditioner and the temperature detector being electrically connected to the PLC controller to maintain the temperature in the withering room between 15 and 28°C.

7. The dynamic indoor static withering system as described in claim 6, wherein, The withering chamber is equipped with at least one row of air ducts, and the air ducts are connected to the air conditioner to deliver the cold air output by the air conditioner to one place in the withering chamber.

8. The dynamic indoor static withering system as described in claim 1 includes a withering rack, which is a partially sealed withering rack, and the withering rack has a plurality of withering platforms arranged at horizontal intervals, so that the withering rack is approximately divided into a plurality of airflow channels, and each airflow channel is provided with a corresponding movable valve on one side; the withering rack is placed in the withering chamber so as to improve the uniformity of the tea leaves being blown by the airflow by carrying tea leaves through each withering platform.

9. The dynamic indoor static withering system as described in claim 8, wherein, The withering chamber is equipped with an isolation wall with an inlet for mounting the withering shelves. This allows the front and rear openings of the airflow ducts of each withering platform to be positioned on opposite sides of the isolation wall, thereby further improving airflow control.

10. The dynamic indoor static withering system as described in claim 1, wherein, This humidity value is a digital signal of 4–20 mA.

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