Intelligent control device and method for tea withering process

Abstract

The present invention provides an intelligent control device and method for a tea withering process, which relates to the technical field of tea preparation, and comprises a withering unit: a first withering box, used for performing preliminary withering on the tea, so that the moisture content of the tea is reduced to a set range; a second withering box, used for performing second-stage withering on the tea, so that the moisture content of the tea is further reduced and the moisture content of the tea is gradually close to a qualified value; a third withering box, used for performing final withering on the tea, so that the moisture content of the tea is reduced to a qualified value; a withering tray, used for fixing the tea and making the tea be heated evenly; a control unit: a data acquisition module, a data analysis module, and a dynamic adjustment module, used for eliminating the influence of the withering tray on the moisture content of the tea according to drying data to obtain the moisture content of the tea, and adjusting the withering environment of the tea according to the change of the moisture content of the tea within a set time. The present invention accurately controls the withering efficiency and withering quality of the tea by controlling the dynamic circulation of the tea inside the withering unit.

Description

Technical Field

[0001] The invention relates to the technical field of tea preparation, and in particular to intelligent control equipment for a tea withering process. Background Art

[0002] Tea withering is an important step in the primary processing of tea, especially in the production of white tea, oolong tea and some green tea. It is one of the key tea-making processes. The main purpose of withering is to reduce the moisture content in fresh leaves, causing physical and chemical changes inside the tea leaves, thereby enhancing the aroma and taste of the tea.

[0003] Existing tea withering methods usually use natural withering or artificial withering. Natural withering has the disadvantages of long time, uneven withering and susceptibility to contamination, while artificial withering is difficult to control and it is difficult to accurately control the moisture content. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an intelligent control device for the withering process of tea leaves, which enables the tea leaves to flow dynamically inside the withering unit through a control unit, thereby accurately controlling the withering efficiency and withering quality of the tea leaves.

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

[0006] An intelligent control device for tea withering process, comprising: a withering unit and a control unit;

[0007] The withering unit includes:

[0008] The first withering box is used to perform preliminary withering on the tea leaves to reduce the moisture content of the tea leaves to a set range;

[0009] The second withering box is used to perform a second withering on the tea leaves, so as to further reduce the moisture content of the tea leaves and gradually bring the moisture content of the tea leaves closer to the qualified value;

[0010] The third withering box is used to perform final withering on the tea leaves to reduce the moisture content of the tea leaves to an acceptable value;

[0011] Withering tray, used to fix the tea leaves and make them evenly heated;

[0012] The control unit includes:

[0013] Data collection module, used to collect drying data during the tea withering process;

[0014] A data analysis module, used to eliminate the influence of the withering tray on the moisture content of the tea leaves according to the drying data to obtain the moisture content of the tea leaves;

[0015] The dynamic adjustment module is used to adjust the withering environment of the tea leaves according to the changes in the moisture content of the tea leaves within a set time.

[0016] Furthermore, the drying data of the tea leaves during withering is collected, including:

[0017] The total spectrum of cotton gauze and tea leaves is collected by a near-infrared spectrometer, and the changes in temperature and humidity during the withering process of tea leaves and the total weight changes of tea leaves and cotton gauze are monitored in real time by sensors.

[0018] Further, the moisture content of the tea leaves is obtained by excluding the influence of the withering tray on the moisture content of the tea leaves according to the drying data, including:

[0019] An interference model is constructed according to the influence of cotton gauze on the total spectrum. The interference of the cotton gauze spectrum is eliminated from the total spectrum according to the interference model and the spectral data of tea is extracted in real time. The real-time moisture content of tea is calculated according to the spectral data of tea. According to the real-time monitored temperature and humidity, the parameters of the interference model are dynamically adjusted to optimize the accuracy of the interference model.

[0020] Furthermore, the withering environment of the tea leaves is adjusted according to the change in the moisture content of the tea leaves within a set time, including:

[0021] Setting a moisture content change rate threshold, and adjusting the positional relationship between the withering tray and the first withering box, the second withering box and the third withering box according to the change rate of the moisture content of the tea leaves;

[0022] The withering tray with higher initial moisture content is allocated inside the first withering box, and when the rate of change of the moisture content of the tea leaves exceeds a threshold value of the rate of change of the moisture content, the withering tray is transferred to the inside of the second withering box;

[0023] When the rate of change of moisture content of the tea leaves in the withering tray located inside the second withering box is higher or lower than a threshold value of the rate of change of moisture content, if the moisture content of the tea leaves in the withering tray reaches a set interval, the withering tray is transferred to the inside of the third withering box only when the rate of change of moisture content of the tea leaves is lower than the threshold value of the rate of change of moisture content; if the moisture content of the tea leaves in the withering tray does not reach the set interval, the withering tray is transferred to the inside of the first withering box or the third withering box;

[0024] When the rate of change of moisture content of the tea leaves in the withering tray located inside the third withering box is lower than the threshold value of moisture content change rate, if the moisture content of the tea leaves in the withering tray reaches the set interval, the position of the withering tray remains unchanged; if the moisture content of the tea leaves in the withering tray does not reach the set interval, the withering tray is transferred to the inside of the second withering box.

[0025] Furthermore, a fixed cylinder is provided inside the first withering box, and two groups of air-permeable partition plates are symmetrically provided on the surface of the fixed cylinder, and each group of the air-permeable partition plates is fixedly connected to the surface of the fixed cylinder in a ring array, and arc-shaped baffles are symmetrically provided in the feed port and the discharge port opened on the surface of the first withering box, respectively, and the arc-shaped baffles are slidably connected in the arc-shaped slide groove opened in the first withering box, and a plurality of arc-shaped springs are provided in the arc-shaped slide groove opened in the first withering box, and both ends of the arc-shaped springs are respectively fixedly connected to the arc-shaped baffles and the first withering box, one end of the first withering box is fixedly connected to a connecting ring body, and a perforated disc is fixedly connected to the inside of the connecting ring body, and a conical cylinder is fixedly connected to one end of the connecting ring body, and a first motor is installed on the surface of the first withering box, and a constraint connecting disk is fixedly connected to the end of the output shaft of the first motor, and the constraint connecting disk is fixedly connected to the fixed cylinder.

[0026] Furthermore, the second withering box is arranged on one side of the discharge port of the first withering box, and the third withering box is arranged on one side of the discharge port of the second withering box. A number of withering lamps are evenly installed on the inner top surface and inner bottom surface of the second withering box and the third withering box. A detection room is arranged on one side of the discharge port of the first withering box, and the detection room is located inside the second withering box and the third withering box. A linear slide is installed on the inner top surface of the detection room, and a near-infrared spectrometer is installed on the surface of the linear slide. Filters and air pumps are installed on the surfaces of the second withering box and the third withering box.

[0027] Furthermore, two turntables are installed on the inner bottom surface of the detection chamber, and the two turntables are respectively located inside the second withering box and the third withering box. Several groups of conveying plates are arranged inside the detection chamber, and each group of conveying plates is symmetrically arranged. Several groups of conveying plates are arranged on the surface of each turntable in a circular array, and the conveying plates are fixedly connected to the corresponding turntable. A group of conveying plates is fixedly connected to the surface of the first withering box at both sides of the discharge port.

[0028] Furthermore, movable guide wheels are respectively arranged near four angular positions on the surface of the transmission plate, and the movable guide wheels are rotatably connected to the transmission plate through a first convex bearing. Two groups of movable wheels are arranged in parallel between the four movable guide wheels, and the movable wheels are rotatably connected to the movable guide wheels through a second convex bearing. Transmission wheels are symmetrically arranged on both sides of the movable wheels, and the transmission wheels respectively conflict with the corresponding movable guide wheels and the movable wheels. The transmission wheel is rotatably connected to the transmission plate through a third convex bearing. An auxiliary wheel is rotatably connected to the surface of the detection chamber through a fixed tube and a fourth bearing. Gears are symmetrically arranged on the surface of the transmission plate, and two of the gears are meshed and connected. The two gears pass through the surface of the transmission plate through two connecting rods and are fixedly connected to two of the movable guide wheels. A second motor is installed on the surface of the transmission plate, and the output shaft of the second motor is fixedly connected to one of the gears. A flexible shaft is arranged on the surface of the other gear, and the two ends of the flexible shaft are respectively fixedly connected to the gear and the auxiliary wheel.

[0029] Furthermore, the withering tray includes a fixed upper frame, a fixed lower frame is arranged below the fixed upper frame, the bottom surface of the fixed upper frame and the upper surface of the fixed lower frame are fixedly connected with thin cotton gauze, the bottom surface of the fixed upper frame is fixedly connected with plug blocks near the four corners, and the surface of the fixed lower frame is provided with slots corresponding to the plug blocks.

[0030] Furthermore, a tea withering method specifically comprises the following steps:

[0031] Step 1: evenly spread the tea leaves on the surface of the thin cotton gauze on the fixed lower frame according to the size of the leaves, and tightly press the fixed upper frame and the fixed lower frame together, so that the plug blocks on the fixed upper frame are inserted into the corresponding slots on the surface of the fixed lower frame to form a withering tray with tea leaves;

[0032] Step 2: Put the withering tray in step 1 into the first withering box through the feed port of the first withering box, and subject the tea leaves in the withering tray to rapid withering after being treated by hot air in the first withering box;

[0033] Step 3, transferring the withering tray after withering in step 2 to the interior of a second withering box, treating the tea leaves with withering lamps in the second withering box, and continuously removing the water evaporated from the tea leaves in the second withering box through filters and air pumps;

[0034] Step 4, transferring the withering tray after withering in step 3 to the interior of a third withering box, treating it with the withering lamp in the second withering box, and continuously removing the water evaporated from the tea leaves in the third withering box through a filter and an air pump;

[0035] Step five, during the process from step two to step four above, the position of the withering tray is regulated by the control unit so that the position of the withering tray is adjusted between the first withering box, the second withering box and the third withering box according to the moisture content of the tea leaves and the threshold value of the rate of change of the moisture content of the tea leaves.

[0036] The above solution of the present invention includes at least the following beneficial effects:

[0037] The above scheme of the present invention can maintain an optimal withering rate for the tea leaves in the withering tray by dynamically switching the withering tray in the first withering box, the second withering box and the third withering box. By successively lowering the temperature in the first withering box, the second withering box and the third withering box, the tea leaves in the withering tray are not easily over-withered, thereby improving the withering efficiency of the tea leaves and ensuring the withering quality of the tea leaves. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the overall structure provided by the present invention.

[0039] Figure 2 It is a schematic diagram of the arc baffle in the present invention.

[0040] Figure 3 It is a schematic diagram of the transfer station of the present invention.

[0041] Figure 4 It is a schematic diagram of the withering tray in the present invention.

[0042] Figure 5 The present invention Figure 3 Enlarged view of point A in the middle.

[0043] Figure 6 The present invention Figure 2 Enlarged view of point B in the middle.

[0044] Figure 7 It is a schematic diagram of the control unit in the present invention.

[0045] In the figure: 101, first withering box; 102, second withering box; 103, third withering box; 104, withering tray; 105, filter; 106, air pump; 107, detection room;

[0046] 201, conical cylinder; 202, connecting ring body; 203, perforated disc; 204, arc baffle; 205, arc spring; 206, air-permeable partition plate; 207, first motor; 208, restraining connecting disc; 209, fixed cylinder;

[0047] 301, transmission plate; 302, mobile guide wheel; 303, mobile wheel; 304, transmission wheel; 305, gear; 306, second motor; 307, flexible shaft; 308, auxiliary wheel;

[0048] 401, linear slide; 402, near-infrared spectrometer; 403, turntable;

[0049] 501, fix the upper frame; 502, thin cotton gauze; 503, insert block; 504, fix the lower frame. DETAILED DESCRIPTION

[0050] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0051] like Figures 1 to 7 As shown, an embodiment of the present invention provides an intelligent control device for tea withering process, including: a withering unit and a control unit;

[0052] The withering unit includes:

[0053] The first withering box 101 is used to perform preliminary withering on the tea leaves to reduce the moisture content of the tea leaves to a set range;

[0054] The second withering box 102 is used to perform a second stage withering on the tea leaves, so as to further reduce the moisture content of the tea leaves and gradually bring the moisture content of the tea leaves closer to the qualified value;

[0055] The third withering box 103 is used to perform final withering on the tea leaves to reduce the moisture content of the tea leaves to an acceptable value;

[0056] The withering tray 104 is used to fix the tea leaves and make the tea leaves be heated evenly;

[0057] The control unit includes:

[0058] Data collection module, used to collect drying data during the tea withering process;

[0059] A data analysis module, used to eliminate the influence of the withering tray 104 on the moisture content of the tea leaves according to the drying data to obtain the moisture content of the tea leaves;

[0060] The dynamic adjustment module is used to adjust the withering environment of the tea leaves according to the changes in the moisture content of the tea leaves within a set time.

[0061] In an embodiment of the present invention:

[0062] Before withering the tea leaves, the tea leaves can be classified by leaf size through a linear screening machine, and tea leaves of the same size can be spread flat inside the withering tray 104, so that the withering progress of each tea leaf tends to be consistent, and the tea leaves spread flat inside the withering tray 104 are not overlapped with each other;

[0063] The temperatures in the first withering box 101, the second withering box 102 and the third withering box 103 are lowered in sequence. The tea leaves in the withering tray 104 are first placed in the first withering box 101 for preliminary withering. The preliminary withering is performed by blowing hot air on both sides of the withering tray 104 in parallel, so that the tea leaves in the withering tray 104 are evenly heated and blown, so that the moisture of the tea leaves is evenly lost.

[0064] When the moisture content of the tea leaves in the first withering box 101 reaches a set range, the withering tray 104 in the first withering box 101 is transferred to the second withering box 102. When the moisture content of the tea leaves in the second withering box 102 reaches a set range, the withering tray 104 is transferred to the third withering box 103.

[0065] In the above process, various data in the withering process of tea leaves are collected by sensors so as to calculate the moisture content of tea leaves in real time. According to the change of moisture content of tea leaves, the positional relationship between the withering tray 104 and the first withering box 101, the second withering box 102 and the third withering box 103 can be dynamically adjusted to make the rate of change of moisture content of tea leaves reach an optimal state, thereby improving the withering rate of tea leaves while ensuring the quality of withering.

[0066] like Figures 1 to 7 As shown, the drying data of tea leaves during withering is collected, including:

[0067] The total spectrum of the cotton gauze and tea leaves is collected by the near infrared spectrometer 402, and the changes in temperature and humidity during the withering process of the tea leaves and the total weight changes of the tea leaves and cotton gauze are monitored in real time by the sensor.

[0068] The moisture content of the tea leaves is obtained by excluding the influence of the withering tray 104 on the moisture content of the tea leaves according to the drying data, including:

[0069] An interference model is constructed according to the influence of cotton gauze on the total spectrum. The interference of the cotton gauze spectrum is eliminated from the total spectrum according to the interference model and the spectral data of tea is extracted in real time. The real-time moisture content of tea is calculated according to the spectral data of tea. According to the real-time monitored temperature and humidity, the parameters of the interference model are dynamically adjusted to optimize the accuracy of the interference model.

[0070] In an embodiment of the present invention, constructing an interference model according to the influence of cotton gauze on the total spectrum may include the following steps:

[0071] S001, in the absence of tea leaves, measure the near-infrared spectra of cotton gauze under different humidity conditions, and record the effects of humidity, time and wavelength on the spectrum of cotton gauze.

[0072] S002, in the absence of cotton gauze, measure the pure spectrum of tea, establish a database of pure spectrum characteristics of tea, and record the changing patterns of pure spectrum of tea under different environmental parameters.

[0073] S003, in actual scenario, measure the total spectrum of the combination of tea leaves and cotton gauze.

[0074] S004, remove interference in the spectrum caused by equipment noise, background light or baseline drift.

[0075] S005, establishing an interference model according to the influence of humidity, time and wavelength on the spectrum of cotton gauze recorded in step S001, and describing the variation of the spectrum characteristics of cotton gauze with humidity and time through the interference model to extract the spectrum characteristics of cotton gauze.

[0076] Specifically, establishing the interference model of cotton gauze may include the following steps:

[0077] S005.1. Data Preprocessing

[0078] The spectral data of cotton gauze under different humidity, time and wavelength conditions are obtained from step S001, and the spectral data of cotton gauze is preprocessed by smoothing filtering, baseline correction and other methods to remove the interference caused by equipment noise, background light or baseline drift, and construct a multidimensional matrix , where rows represent measurement samples and columns represent wavelengths (spectral features).

[0079] Data matrix form:

[0080] ;

[0081] in, is the number of samples, is the number of wavelengths.

[0082] In order to eliminate the influence of the magnitude difference of spectral signal intensity between different wavelengths, the matrix After standardization, the standard deviation formula is:

[0083] ;

[0084] in, is the mean of each column, is the standard deviation of each column.

[0085] S005.2, Calculate the standardized data The covariance matrix can describe the correlation between wavelengths, and the high correlation features can be reduced in dimension. The covariance formula is:

[0086] ;

[0087] in, is the transpose symbol of the matrix, yes The transpose of , that is, swapping rows and columns.

[0088] S005.3, covariance matrix Perform eigenvalue decomposition to obtain eigenvalues ​​and eigenvectors. The eigenvalue decomposition formula is:

[0089] ;

[0090] in, is a diagonal matrix containing the eigenvalues ​​of the covariance matrix, is the eigenvector matrix corresponding to each eigenvalue, is the transpose symbol.

[0091] S005.4, for the eigenvalues, sort them in descending order and select the cumulative contribution rate Reach 95% of the front The principal components are used to retain the main information of the original spectral data to the maximum extent, while reducing the dimension to remove redundant features. The cumulative contribution rate formula is:

[0092] ;

[0093] in, It is Features, is the index, Indicates the number of principal components selected (previous principal components), Represents the total number of principal components (or the number of all eigenvalues).

[0094] Use the original normalized data Project to Selected In each principal component direction, the principal component score matrix is ​​obtained , the principal component score matrix It is the spectral feature data after dimension reduction, which contains the main change information of cotton yarn spectrum. The main component score formula is:

[0095] ;

[0096] in, It corresponds to the previous The eigenvector matrix of the principal components.

[0097] S005.5, Fitting humidity and time to principal component scores using multiple linear regression The prediction accuracy of the principal component interference model is verified by test data, and the mean square error is calculated. The formula for the mean square error is:

[0098] ;

[0099] in, Indicates The actual data of principal component scores, Indicates The predicted data of principal component scores, is the total number of test data samples.

[0100] Specifically, S005.5 may include the following steps:

[0101] S005.5.1, take humidity and time as input variables to form a data matrix :

[0102] ;

[0103] in, Indicates The humidity of the samples, Indicates The time of a sample.

[0104] S005.5.2, score the principal components The first principal component of :

[0105] ;

[0106] Among them, the target variable It can also be other key principal components.

[0107] S005.5.3, Multiple Linear Regression Assumptions Principal Component Scores The relationship with humidity and time is:

[0108] ;

[0109] in, is the intercept, and are regression coefficients, representing the effects of humidity and time on the principal component scores, is the error term, For humidity, Humidity The corresponding measurement time.

[0110] It can be expressed as a matrix:

[0111] ;

[0112] in:

[0113] ;

[0114] Among them, 1 is the constant term of the intercept term, is the coefficient vector.

[0115] S005.5.4, use the least squares method (OLS) to solve the regression coefficient β so that the sum of squared errors is minimized:

[0116] ;

[0117] in, is the regression coefficient obtained by fitting.

[0118] Calculate the principal component scores of the fit :

[0119] ;

[0120] Among them, in In the samples Each row of results in represents the predicted data of the principal component score , is the actual data with the principal component scores The comparisons were performed to assess the critical components of the disturbance model errors.

[0121] S005.5.5, by coefficient of determination To measure the goodness of fit of the interference model, the coefficient of determination The formula is:

[0122] ;

[0123] in, is the mean of the principal component scores, is the sample size.

[0124] If the coefficient of determination Close to 1, indicating that the interference model explains it well and , The relationship between.

[0125] S005.5.6, for new sample humidity and time data, use the fitted interference model to predict the principal component scores:

[0126] ;

[0127] The interference model is continuously updated based on new data to improve the fitting accuracy.

[0128] S006, establishing a tea pure spectrum characteristic database based on the tea pure spectrum measured in step S002, and recording the variation pattern of the tea pure spectrum under different environmental parameters (such as humidity and temperature).

[0129] In another preferred embodiment of the present invention, if the coefficient of determination is If the value of is low, it means that the interference characteristics during the withering process of tea are complex and there is a nonlinear relationship (for example, when the humidity of the tea withering environment changes extremely, the response of the sensor changes nonlinearly). Combined with the total spectrum of the combination of tea and cotton gauze measured in step S003, the contribution of cotton gauze to the total spectrum is removed by using the interference model established in step S005, and the approximate pure spectrum of tea is extracted through the prediction model.

[0130] The specific steps may include:

[0131] From the interference model established in step S005, obtain the cotton gauze spectrum and the total spectrum ;

[0132] Input Data : Cotton gauze spectral data matrix, each row represents the spectral samples under different humidity, time and other conditions;

[0133] Target Output : The combined spectrum (total spectrum) minus the pure spectrum of tea, that is, the interference contribution of cotton gauze in the spectrum.

[0134] Obtaining pure spectrum of tea leaves from real data The approximate value of is used as the target value during training.

[0135] For input data and output target Normalization or standardization is performed to accelerate the convergence of the neural network.

[0136] Designing predictive models

[0137] Input layer: The number of input nodes is equal to the dimension of the spectral characteristics of the cotton gauze, that is, the number of wavelengths of the spectrum.

[0138] Hidden layer: Use a multi-layer fully connected neural network, each layer can contain 64, 128 or more neurons, and the specific parameters can be adjusted continuously through experiments.

[0139] The activation function uses ReLU to enhance the network's ability to fit nonlinear features.

[0140] Output layer: The number of output nodes is equal to the feature dimension of the target spectrum. The activation function can choose linear activation (Identity Function) to ensure that the output is a continuous value.

[0141] Loss function: Use mean square error (MSE) as the loss function to evaluate the predicted spectrum And target tea pure spectrum The mean square error of

[0142] Use the Adam optimizer (Adaptive Moment Estimation) to speed up network training and optimization.

[0143] Training the prediction model

[0144] The data was divided into training set, validation set and test set in the ratio of 7:2:1. Input network, target output corresponding , adjust the weights and biases of the network through back propagation, minimize the loss function, observe the training loss and verification loss curves, avoid overfitting, and save the best prediction model parameters after training for subsequent inference.

[0145] The total spectrum And cotton gauze spectrum The network output is the predicted cotton gauze spectral contribution, which is input into the trained prediction model. The predicted cotton gauze spectral contribution is subtracted from the total spectrum to obtain the approximate pure spectrum of tea, and the prediction result is restored from the normalized numerical range to the original spectral range.

[0146] Predictive model evaluation

[0147] The residual between the actual pure spectrum of tea and the predicted pure spectrum of tea is calculated. The smaller the residual, the better the prediction effect of the prediction model on the pure spectrum of tea. The larger the residual, the more likely the prediction model may have underfitting or overfitting problems.

[0148] Calculate the mean square error and the coefficient of determination (refer to step S005.5.5) to evaluate the accuracy of the prediction model for spectral separation.

[0149] At the same time, the tea weight corresponding to the predicted data is calculated according to the prediction of the prediction model and compared with the tea weight detected in real time. If the difference is large, the prediction result may be wrong.

[0150] Applying predictive models

[0151] In the actual scenario, the new total spectrum is input into the prediction model to predict and remove the cotton yarn spectrum contribution in real time and extract the pure spectrum of tea.

[0152] If the input conditions change, such as the spectral equipment is adjusted or the cotton yarn material changes, the prediction model can be retrained or fine-tuned with the new data.

[0153] like Figures 1 to 6 As shown, according to the change of the moisture content of the tea leaves within the set time, the withering environment of the tea leaves is adjusted, including:

[0154] Setting a moisture content change rate threshold, and adjusting the positional relationship between the withering tray 104 and the first withering box 101, the second withering box 102 and the third withering box 103 according to the change rate of the moisture content of the tea leaves;

[0155] The withering tray 104 with a higher initial moisture content is allocated inside the first withering box 101. When the rate of change of the moisture content of the tea leaves exceeds a threshold value of the rate of change of the moisture content, the withering tray 104 is transferred to the inside of the second withering box 102.

[0156] When the rate of change of the moisture content of the tea leaves in the withering tray 104 located inside the second withering box 102 is higher or lower than the threshold value of the rate of change of the moisture content, if the moisture content of the tea leaves in the withering tray 104 reaches the set interval, the withering tray 104 is transferred to the inside of the third withering box 103 only when the rate of change of the moisture content of the tea leaves is lower than the threshold value of the rate of change of the moisture content; if the moisture content of the tea leaves in the withering tray 104 does not reach the set interval, the withering tray 104 is transferred to the inside of the first withering box 101 or the third withering box 103;

[0157] When the rate of change of moisture content of the tea leaves in the withering tray 104 located inside the third withering box 103 is lower than the threshold value of the rate of change of moisture content, if the moisture content of the tea leaves in the withering tray 104 reaches the set interval, the position of the withering tray 104 remains unchanged; if the moisture content of the tea leaves in the withering tray 104 does not reach the set interval, the withering tray 104 is transferred to the inside of the second withering box 102.

[0158] In the embodiment of the present invention, the wind speed and temperature inside the first withering box 101, the second withering box 102 and the third withering box 103 are constant. According to the historical data of tea withering, the optimal moisture content change rate of tea at different temperatures is extracted. For example, when the moisture content change rate exceeds a certain value, excessive withering occurs, causing the tea to dry too quickly, resulting in insufficient aroma or generation of peculiar smell, darkening or yellowing of the color, and other phenomena affecting the quality of the tea. Then, the optimal moisture content change rate value is less than the change rate value;

[0159] Set the moisture content of tea leaves to %to % withering tray 104 no longer enters the interior of the first withering box 101, and the moisture content of the tea leaves is between Withering trays 104 below % no longer enter the interior of the first withering box 101 and the second withering box 102.

[0160] Set the optimal moisture content change rate threshold for ,in, The moisture content change rate closest to excessive withering in historical data, is the interval length, which can be adjusted according to production requirements, such as the withering efficiency of tea leaves. Make adjustments, The smaller it is, the smaller the rate of change of the moisture content of the tea leaves fluctuates and is always maintained at a high level.

[0161] During the tea withering process, the withering tray 104 is first placed inside the first withering box 101 to perform withering operation. The relatively high temperature of the first withering box 101 keeps the withering rate of the tea leaves at a relatively fast speed.

[0162] If the rate of change of the moisture content of the tea leaves is higher than the threshold value of the rate of change of the moisture content corresponding to the temperature in the first withering box 101 , the withering tray 104 is transferred from the first withering box 101 to the second withering box 102. If the moisture content change rate of the tea leaves in the withering tray 104 in the second withering box 102 is higher than the moisture content change rate threshold value corresponding to the temperature in the second withering box 102, , the withering tray 104 is transferred from the second withering box 102 to the inside of the third withering box 103.

[0163] If the rate of change of the moisture content of the tea leaves in the withering tray 104 in the third withering box 103 is lower than the threshold value of the rate of change of the moisture content corresponding to the temperature in the third withering box 103 , and the moisture content of the tea leaves in the withering tray 104 is higher than %, the withering tray 104 is transferred to the interior of the second withering box 102, otherwise the position of the withering tray 104 remains unchanged;

[0164] If the rate of change of the moisture content of the tea leaves in the withering tray 104 in the second withering box 102 is lower than the threshold value of the rate of change of the moisture content corresponding to the temperature in the second withering box 102 , and the moisture content of the tea leaves in the withering tray 104 is higher than %, the withering tray 104 is transferred to the interior of the first withering box 101, otherwise the position of the withering tray 104 remains unchanged;

[0165] The first withering box 101 is provided with a fixed cylinder 209 inside, and two groups of air-permeable partition plates 206 are symmetrically provided on the surface of the fixed cylinder 209. Each group of air-permeable partition plates 206 is fixedly connected to the surface of the fixed cylinder 209 in a circular array. The feed port and the discharge port opened on the surface of the first withering box 101 are symmetrically provided with arc baffles 204 respectively. The arc baffles 204 are slidably connected to the arc chute opened inside the first withering box 101. A plurality of arc springs 204 are provided in the arc chute opened inside the first withering box 101. 5. The two ends of the arc spring 205 are fixedly connected to the arc baffle 204 and the first withering box 101 respectively. One end of the first withering box 101 is fixedly connected to a connecting ring body 202. The interior of the connecting ring body 202 is fixedly connected to a perforated disc 203. One end of the connecting ring body 202 is fixedly connected to a conical cylinder 201. A first motor 207 is installed on the surface of the first withering box 101. The end of the output shaft of the first motor 207 is fixedly connected to a constraining connecting disk 208. The constraining connecting disk 208 is fixedly connected to a fixed cylinder 209.

[0166] The second withering box 102 is arranged on one side of the discharge port of the first withering box 101, and the third withering box 103 is arranged on one side of the discharge port of the second withering box 102. A number of withering lamps are evenly installed on the inner top surface and inner bottom surface of the second withering box 102 and the third withering box 103. A detection chamber 107 is arranged on one side of the discharge port of the first withering box 101. The detection chamber 107 is located inside the second withering box 102 and the third withering box 103. A linear slide 401 is installed on the inner top surface of the detection chamber 107. A near-infrared spectrometer 402 is installed on the surface of the linear slide 401. Filters 105 and air pumps 106 are installed on the surfaces of the second withering box 102 and the third withering box 103.

[0167] Two turntables 403 are installed on the inner bottom surface of the detection chamber 107, and the two turntables 403 are respectively located inside the second withering box 102 and the third withering box 103. A plurality of groups of conveying plates 301 are arranged inside the detection chamber 107, and each group of conveying plates 301 is symmetrically arranged. A plurality of groups of conveying plates 301 are arranged on the surface of each turntable 403 in a circular array, and the conveying plates 301 are fixedly connected to the corresponding turntable 403. A group of conveying plates 301 is fixedly connected to the surface of the first withering box 101 at both sides of the discharge port.

[0168] The surface of the conveying plate 301 is provided with movable guide wheels 302 near the four corner positions, respectively. The movable guide wheels 302 are rotatably connected to the conveying plate 301 through the first convex bearing. Two groups of movable wheels 303 are arranged in parallel between the four movable guide wheels 302. The movable wheels 303 are rotatably connected to the movable guide wheels 302 through the second convex bearing. Transmission wheels 304 are symmetrically arranged on both sides of the movable wheels 303. The transmission wheels 304 are respectively in conflict with the corresponding movable guide wheels 302 and the movable wheels 303. The transmission wheels 304 are rotatably connected to the conveying plate 301 through the third convex bearing. The surface of 107 is rotatably connected with an auxiliary wheel 308 through a fixed tube and a fourth bearing, and gears 305 are symmetrically arranged on the surface of the transmission plate 301. The two gears 305 are meshingly connected, and the two gears 305 pass through the surface of the transmission plate 301 through two connecting rods and are fixedly connected to two of the movable guide wheels 302. A second motor 306 is installed on the surface of the transmission plate 301, and the output shaft of the second motor 306 is fixedly connected to one of the gears 305. A soft shaft 307 is arranged on the surface of the other gear 305, and the two ends of the soft shaft 307 are respectively fixedly connected to the gear 305 and the auxiliary wheel 308.

[0169] The withering tray 104 includes a fixed upper frame 501, a fixed lower frame 504 is arranged below the fixed upper frame 501, the bottom surface of the fixed upper frame 501 and the upper surface of the fixed lower frame 504 are fixedly connected with thin cotton gauze 502, the bottom surface of the fixed upper frame 501 near the four corners are fixedly connected with plug blocks 503, and the surface of the fixed lower frame 504 is provided with slots corresponding to the plug blocks 503.

[0170] In the embodiment of the present invention, tea leaves of the same size are evenly spread on the surface of the thin cotton gauze 502 on the fixed lower frame 504, and the insert block 503 on the thin cotton gauze 502 is inserted into the corresponding slot on the surface of the fixed lower frame 504. At this time, the two thin cotton gauze 502 fix the tea leaves.

[0171] The withering tray 104 with tea leaves fixed thereon is put into the first withering box 101 from the feed port of the first withering box 101, and the first motor 207 is controlled to operate so that the first motor 207 drives the fixed cylinder 209 to rotate through the constraining connecting disk 208 until the withering tray 104 is engaged by the gap formed by four of the breathable partition plates 206. The perforated disk 203 and the constraining connecting disk 208 are fitted with the two side edges of the withering tray 104, so that the withering tray 104 is not easy to move in the radial direction of the fixed cylinder 209. The breathable partition plate 206 fitted with the withering tray 104 makes it difficult for the fixed upper frame 501 and the fixed lower frame 504 to separate, thereby keeping the position of the tea leaves inside the withering tray 104 stable.

[0172] An external heat source device is used to pump dry hot air into the interior of the conical cylinder 201. The dry hot air is evenly blown into the interior of the first withering box 101 through the perforated disc 203 inside the connecting ring body 202, and is blown in a direction parallel to the surface of the withering tray 104, and the water vapor evaporated from the tea leaves in the withering tray 104 is blown out from the small holes on the surface of the air permeable partition plate 206 away from the conical cylinder 201.

[0173] The withering tray 104 is transferred between the first withering box 101, the second withering box 102 and the third withering box 103 through the conveying plate 301. Specifically, the second motors 306 on the surfaces of the two corresponding conveying plates 301 are started at the same time, so that the operation of the two second motors 306 drives the corresponding moving guide wheels 302 to rotate through the transmission of the gear 305. The rotation of the moving guide wheel 302 causes the transmission wheel 304 and the moving wheel 303 to rotate synchronously through the transmission. The withering tray 104 enters between the two conveying plates 301, rubs against the corresponding moving guide wheels 302 and the moving wheel 303 through the upper surface of the fixed upper frame 501, and rubs against the corresponding moving guide wheels 302 and the moving wheel 303 through the bottom surface of the fixed lower frame 504, so that the withering tray 104 moves.

[0174] When the withering tray 104 enters and exits the first withering box 101, it will push the arc baffle 204, causing the arc baffle 204 to move in the arc slide groove of the first withering box 101 toward the direction of the compression arc spring 205 to facilitate the entry and exit of the withering tray 104. When the arc baffle 204 is not in contact with the withering tray 104, under the action of the arc spring 205, the two corresponding arc baffles 204 are caused to conflict with each other to prevent the airflow in the first withering box 101 from overflowing.

[0175] When the withering tray 104 located inside the first withering box 101 is transferred to the inside of the second withering box 102 through the corresponding two conveying plates 301, the turntable 403 close to the first withering box 101 is controlled to rotate an unloaded conveying plate 301 to be opposite to the withering tray 104 to be transferred, so that the withering tray 104 is transferred from the conveying plate 301 on the surface of the first withering box 101 to the conveying plate 301 corresponding to the surface of the turntable 403. The transfer process starts the second motor 306 to drive the rotation of the moving guide wheel 302, the moving wheel 303 and the transmission wheel 304, so that the withering tray 104 moves under the action of the friction force of the moving guide wheel 302 and the moving wheel 303.

[0176] The withering tray 104 located inside the second withering box 102 is transferred to the third withering box 103 through the corresponding two conveying plates 301 , which is the same as the method of transferring the withering tray 104 from the first withering box 101 to the second withering box 102 .

[0177] For monitoring the moisture content of tea leaves in the withering tray 104, when the withering tray 104 is inside the first withering box 101, the withering tray 104 to be monitored inside the first withering box 101 is rotated to fit with the auxiliary wheel 308, and the linear slide 401 is used to control its slide to move the near-infrared spectrometer 402 to be directly above the two conveying plates 301 on the surface of the first withering box 101, and the second motor 306 on the surface of the conveying plate 301 is controlled to run, and the operation of the flexible shaft 307 is driven by the gear 305 to drive the auxiliary wheel 308 to rotate, and the rotation of the auxiliary wheel 308 drives the withering tray 104 in contact with its surface to move between the two conveying plates 301 on the surface of the first withering box 101 for monitoring by the near-infrared spectrometer 402.

[0178] When the conveying plate 301 on the surface of the first withering box 101 and the conveying plates 301 on the surfaces of the two turntables 403 rotate to the bottom of the linear slide 401, the position of the near-infrared spectrometer 402 can be moved by the linear slide 401 to monitor the withering tray 104, and the two boxes of the detection chamber 107 can reduce the impact of the withering lamps inside the second withering box 102 and the third withering box 103.

[0179] A tea withering method comprises the following steps:

[0180] Step 1: evenly spread the tea leaves on the surface of the thin cotton gauze 502 on the fixed lower frame 504 according to the size of the leaves, tightly press the fixed upper frame 501 and the fixed lower frame 504, so that the plug block 503 on the fixed upper frame 501 is inserted into the corresponding slot on the surface of the fixed lower frame 504, forming a withering tray 104 with tea leaves;

[0181] Step 2: Put the withering tray 104 prepared in step 1 into the first withering box 101 through the feed port of the first withering box 101, and subject the tea leaves in the withering tray 104 to rapid withering after being treated by hot air in the first withering box 101;

[0182] Step 3, transferring the withering tray 104 after withering in step 2 to the interior of the second withering box 102, and subjecting the withering lamp in the second withering box 102 to treatment, and continuously removing the water evaporated from the tea leaves in the second withering box 102 through the filter 105 and the air pump 106;

[0183] Step 4: transfer the withering tray 104 after withering in step 3 to the interior of the third withering box 103, and process it under the withering lamp in the second withering box 102, and continuously remove the water evaporated from the tea leaves in the third withering box 103 through the filter 105 and the air pump 106;

[0184] Step five, during the process from step two to step four above, the position of the withering tray 104 is regulated by the control unit so that the position of the withering tray 104 is adjusted between the first withering box 101, the second withering box 102 and the third withering box 103 according to the moisture content of the tea leaves and the threshold value of the rate of change of the moisture content of the tea leaves.

[0185] It should be noted that the gear 305 is fixedly connected to the corresponding transmission plate 301 through a connecting rod, and the connecting rod passes through the transmission plate 301 and is rotatably connected to the transmission plate 301, so that the rotation of the gear 305 drives the auxiliary wheel 308 to rotate;

[0186] The surface of the air-permeable partition plate 206 is evenly provided with a number of small holes to facilitate the passage of gas;

[0187] The auxiliary wheel 308 is made of rubber, so that when the fixed cylinder 209 drives the air-permeable partition plate 206 to rotate, the auxiliary wheel 308 is elastically deformed to prevent the auxiliary wheel 308 from blocking the rotation of the air-permeable partition plate 206. When the fixed cylinder 209 no longer rotates, the auxiliary wheel 308 contacts one of the withering trays 104, so that the auxiliary wheel 308 drives the withering tray 104 to move by rotating without interfering with the rotation of the air-permeable partition plate 206.

[0188] The detection chamber 107 is in the shape of two box bodies symmetrically arranged inside the second withering box 102 and the third withering box 103, the box body has an opening, the two box body openings are opposite, the box body located at the upper side is fixed to the inner top surface of the second withering box 102 and the third withering box 103, the box body located at the lower side is fixed to the inner bottom surface of the second withering box 102 and the third withering box 103, the linear slide 401 is installed in the box body located at the upper side, and the distance between the two box bodies is enough for the transfer plate 301 to rotate around the turntable 403. This arrangement facilitates the transfer and monitoring of the withering tray 104;

[0189] The withering lamp can be an LED lamp. Depending on the type of tea, different LED lamps are set to provide specific wavelengths of light such as red light, blue light, etc. to affect the development of the aroma and taste of the tea leaves;

[0190] The air inlet of the filter 105 is connected to the interior of the second withering box 102 or the third withering box 103 through a pipeline, and the air outlet of the filter 105 is connected to the corresponding air inlet of the air pump 106 through a pipeline, and the air outlet of the air pump 106 is connected to the interior of the second withering box 102 or the third withering box 103 through a pipeline, so as to control the humidity inside the second withering box 102 and the third withering box 103, thereby improving the withering efficiency of the tea leaves, wherein the connection method of the pipeline can be a threaded thread groove or a reserved notch, so that the pipe mouth is fixed inside the reserved notch, which is well known in the prior art and will not be described in detail here;

[0191] Small holes are evenly formed on the surface of the perforated disc 203 so as to allow the airflow passing through the perforated disc 203 to be evenly blown toward the first withering box 101 .

[0192] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An intelligent control device for tea withering process, characterized in that: include: Withering units and control units; The withering unit includes: The first withering box is used to perform preliminary withering on the tea leaves to reduce the moisture content of the tea leaves to a set range; The second withering box is used to perform a second withering on the tea leaves, so as to further reduce the moisture content of the tea leaves and gradually bring the moisture content of the tea leaves closer to the qualified value; The third withering box is used to perform final withering on the tea leaves to reduce the moisture content of the tea leaves to an acceptable value; Withering tray, used to fix the tea leaves and make them evenly heated; The control unit includes: Data collection module, used to collect drying data during the tea withering process; A data analysis module, used to eliminate the influence of the withering tray on the moisture content of the tea leaves according to the drying data to obtain the moisture content of the tea leaves; A dynamic adjustment module is used to adjust the withering environment of tea leaves according to the change in moisture content of the tea leaves within a set time, including: setting a moisture content change rate threshold, and adjusting the positional relationship between the withering tray and the first withering box, the second withering box and the third withering box according to the change rate of the moisture content of the tea leaves; the withering tray where the tea leaves with a higher initial moisture content are located is allocated inside the first withering box, and when the rate of change of the moisture content of the tea leaves exceeds the threshold value of the moisture content change rate, the withering tray is transferred to the inside of the second withering box; when the rate of change of the moisture content of the tea leaves in the withering tray located inside the second withering box is higher or lower than the threshold value of the moisture content change rate, If the moisture content of the tea leaves in the withering tray reaches the set interval, the withering tray will be transferred to the interior of the third withering box only when the rate of change of the moisture content of the tea leaves is lower than the threshold value of the moisture content change rate; if the moisture content of the tea leaves in the withering tray does not reach the set interval, the withering tray will be transferred to the interior of the first withering box or the third withering box; when the rate of change of the moisture content of the tea leaves in the withering tray located inside the third withering box is lower than the threshold value of the moisture content change rate, if the moisture content of the tea leaves in the withering tray reaches the set interval, the position of the withering tray will be maintained unchanged; if the moisture content of the tea leaves in the withering tray does not reach the set interval, the withering tray will be transferred to the interior of the second withering box.

2. The intelligent control device for tea withering process according to claim 1, characterized in that: Collect drying data during the tea withering process, including: The total spectrum of the cotton gauze and tea leaves is collected by a near-infrared spectrometer (402), and the changes in temperature and humidity during the withering process of the tea leaves and the changes in the total weight of the tea leaves and cotton gauze are monitored in real time by a sensor.

3. The intelligent control device for tea withering process according to claim 2, characterized in that: The moisture content of the tea leaves is obtained by excluding the effect of the withering tray (104) on the moisture content of the tea leaves according to the drying data, including: An interference model is constructed according to the influence of cotton gauze on the total spectrum. The interference of the cotton gauze spectrum is eliminated from the total spectrum according to the interference model and the spectral data of tea is extracted in real time. The real-time moisture content of tea is calculated according to the spectral data of tea. According to the real-time monitored temperature and humidity, the parameters of the interference model are dynamically adjusted to optimize the accuracy of the interference model.

4. The intelligent control device for tea withering process according to claim 3, characterized in that: A fixed cylinder (209) is arranged inside the first withering box (101), and two groups of air-permeable partition plates (206) are symmetrically arranged on the surface of the fixed cylinder (209), and each group of the air-permeable partition plates (206) is fixedly connected to the surface of the fixed cylinder (209) in a circular array. Arc baffles (204) are symmetrically arranged in the feed port and the discharge port opened on the surface of the first withering box (101), and the arc baffles (204) are slidably connected in the arc chute opened in the first withering box (101). A plurality of arc springs (205) are arranged in the arc chute opened in the first withering box (101). The two ends of the spring (205) are respectively fixedly connected to the arc-shaped baffle (204) and the first withering box (101); one end of the first withering box (101) is fixedly connected to a connecting ring body (202); the interior of the connecting ring body (202) is fixedly connected to a perforated disc (203); one end of the connecting ring body (202) is fixedly connected to a conical cylinder (201); a first motor (207) is mounted on the surface of the first withering box (101); the end of the output shaft of the first motor (207) is fixedly connected to a constraining connecting disc (208); and the constraining connecting disc (208) is fixedly connected to the fixed cylinder (209).

5. The intelligent control device for tea withering process according to claim 4, characterized in that: The second withering box (102) is arranged on one side of the discharge port of the first withering box (101), and the third withering box (103) is arranged on one side of the discharge port of the second withering box (102). A plurality of withering lamps are evenly installed on the inner top surface and inner bottom surface of the second withering box (102) and the third withering box (103). A detection chamber (107) is arranged on one side of the discharge port of the first withering box (101). The detection chamber (107) is located inside the second withering box (102) and the third withering box (103). A linear slide (401) is installed on the inner top surface of the detection chamber (107). A near-infrared spectrometer (402) is installed on the surface of the linear slide (401). Filters (105) and air pumps (106) are installed on the surfaces of the second withering box (102) and the third withering box (103).

6. The intelligent control device for tea withering process according to claim 5, characterized in that: Two turntables (403) are installed on the inner bottom surface of the detection chamber (107), and the two turntables (403) are respectively located inside the second withering box (102) and the third withering box (103). A plurality of groups of conveying plates (301) are arranged inside the detection chamber (107), and each group of conveying plates (301) are symmetrically arranged. A plurality of groups of conveying plates (301) are arranged on the surface of each turntable (403) in a circular array, and the conveying plates (301) are fixedly connected to the corresponding turntable (403). A group of conveying plates (301) are fixedly connected to the surface of the first withering box (101) at both sides of the discharge port.

7. The intelligent control device for tea withering process according to claim 6, characterized in that: The surface of the conveying plate (301) is provided with movable guide wheels (302) near four corner positions, respectively. The movable guide wheels (302) are rotatably connected to the conveying plate (301) via a first convex bearing. Two groups of movable wheels (303) are arranged in parallel between the four movable guide wheels (302). The movable wheels (303) are rotatably connected to the movable guide wheels (302) via a second convex bearing. Transmission wheels (304) are symmetrically arranged on both sides of the movable wheels (303). The transmission wheels (304) are respectively in conflict with the corresponding movable guide wheels (302) and the movable wheels (303). The transmission wheels (304) are rotatably connected to the conveying plate (301) via a third convex bearing. The surface of the chamber (107) is rotatably connected to an auxiliary wheel (308) via a fixed tube and a fourth bearing; gears (305) are symmetrically arranged on the surface of the transmission plate (301); two gears (305) are meshedly connected; the two gears (305) penetrate the surface of the transmission plate (301) via two connecting rods and are fixedly connected to two of the movable guide wheels (302); a second motor (306) is installed on the surface of the transmission plate (301); an output shaft of the second motor (306) is fixedly connected to one of the gears (305); a flexible shaft (307) is arranged on the surface of the other gear (305); two ends of the flexible shaft (307) are respectively fixedly connected to the gear (305) and the auxiliary wheel (308).

8. The intelligent control device for tea withering process according to claim 7, characterized in that: The withering tray (104) comprises a fixed upper frame (501), a fixed lower frame (504) is arranged below the fixed upper frame (501), the bottom surface of the fixed upper frame (501) and the upper surface of the fixed lower frame (504) are both fixedly connected with thin cotton gauze (502), the bottom surface of the fixed upper frame (501) near the four corners are all fixedly connected with plug blocks (503), and the surface of the fixed lower frame (504) is provided with slots corresponding to the plug blocks (503).

9. A method for withering tea leaves, applied to the apparatus as claimed in any one of claims 1 to 8, comprising the following steps: Step 1, evenly spread the tea leaves on the surface of the thin cotton gauze (502) on the fixed lower frame (504) according to the size of the leaves, tightly press the fixed upper frame (501) and the fixed lower frame (504), so that the plug block (503) on the fixed upper frame (501) is inserted into the corresponding slot on the surface of the fixed lower frame (504), so as to form a withering tray (104) with tea leaves; Step 2, the withering tray (104) in step 1 is put into the interior of the first withering box (101) through the feed port of the first withering box (101), and the tea leaves in the withering tray (104) are firstly rapidly withered after being treated by hot air in the first withering box (101); Step 3, transferring the withering tray (104) after withering in step 2 to the interior of a second withering box (102), subjecting the tea leaves to withering lamp treatment in the second withering box (102), and continuously removing moisture evaporated from the tea leaves in the second withering box (102) through a filter (105) and an air pump (106); Step 4, transferring the withering tray (104) that has been withered in step 3 to the interior of a third withering box (103), subjecting it to treatment by the withering lamp in the second withering box (102), and continuously removing moisture evaporated from the tea leaves in the third withering box (103) through a filter (105) and an air pump (106); Step 5. During the process from step 2 to step 4, the position of the withering tray (104) is regulated by the control unit so that the position of the withering tray (104) is adjusted between the first withering box (101), the second withering box (102) and the third withering box (103) according to the moisture content of the tea leaves and the threshold value of the rate of change of the moisture content of the tea leaves.

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