JPH0224507B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention utilizes a control means with high calculation functions such as a microcomputer to adjust the temperature and air volume of hot air, which are the main elements of control, to optimal values throughout the tea manufacturing and roughening process. This invention relates to a method for rough rolling tea. [Prior art and its problems] The tea manufacturing process involves rolling the tea leaves steamed in the previous process in a rolling drying chamber, or gradually drying them with hot air while stirring until the moisture content on a dry weight basis reaches approximately 100%. During the operation, it is important to maintain the temperature of the tea leaves at around 35℃ without over-drying, and to dry the tea leaves as constant as possible. This will lead to quality deterioration such as yellowing of leaves, fine powder, grassy odor, and musky smell. Conventional methods for sequentially changing the temperature and flow rate of hot air as described above as the rough rolling process progresses include, for example, the inventions disclosed in JP-A-58-47433 and JP-A-58-51844. These are made by dividing the first rough rolling process into multiple steps and sequentially changing the hot air temperature, air volume, etc. for each divided step. Store it in the memory and prepare it, select one from the above ready-made patterns according to the properties of the input tea leaves, and perform the coarse rolling process according to the ready-made pattern for a separately set coarse rolling time. In addition, it is said that the leaf batting time can be set arbitrarily. Although each main element is controlled using a microcomputer, there are the following problems. In other words, tea leaves are living things, and they vary greatly depending on the time of picking, the variety, the yearly rainfall and sunshine hours in the region of production, and the type of steaming treatment. It is unreasonable to apply it. In addition, the temperature of tea leaves, drying speed, etc. during the rough rolling process are determined by the means for generating hot air before heating to produce hot air.
Since it is greatly affected by the condition of the surrounding air (temperature, humidity), even if control is performed according to the established pattern without considering the condition of the surrounding air,
It is difficult to maintain the temperature of tea leaves at around 35℃ and to dry tea leaves at a constant rate. This problem cannot be solved by increasing or decreasing the leaf beating time. [Problems to be Solved by the Invention] The present invention has been made to solve the above-mentioned problems. To provide a tea manufacturing and rough rolling method that allows the air volume to be changed to an optimum value, and also allows the hot air volume and rough rolling time to be determined so as to maximize the ability of the hot air generating means used in the rough rolling process. The purpose of the present invention is to provide a rough rolling machine, improve the quality of tea leaves, reduce the burden on workers, and efficiently perform rough rolling processing of tea leaves. [Means for Solving the Problems] In order to achieve the above-mentioned object, the tea manufacturing and rough rolling method according to the present invention divides one rough rolling process into a plurality of stages or a large number of stages, and maintains the tea leaf temperature at a predetermined optimum temperature. In a tea manufacturing and roughening method in which the temperature, air volume, spindle rotation speed, etc. of hot air are adjusted by a control means so as to be maintained at The optimal hot air temperature is determined based on the wet and dry bulb temperature of the air, and the optimal hot air volume is determined based on the ratio set in advance to the standard air volume according to the properties of the tea leaves and the standard air volume based on the maximum air volume of the hot air generating means. Then, based on the above-mentioned optimum hot air temperature and reference air volume, the properties of the tea leaves to be introduced, and the input amount, the optimum coarse rolling process time is divided by the above-mentioned number of stages to obtain each stage time, and each of the above-mentioned set values is determined. is the set value at each stage time above, and during the process, the tea leaves are roughly rubbed according to the above set values, and the tea leaf temperature is actually measured at each stage, and the set value of the tea leaf temperature and the above measured value are The feature is that the temperature and air volume of the hot air are compared and adjusted according to the difference so as to reduce the difference to maintain and control the tea leaf temperature at the optimum temperature. [Example] An example of the present invention will be described based on FIGS. 1 to 3. The tea milling machine A and the hot air generator B have a conventionally well-known configuration.To explain each sensor necessary to carry out the rough milling method of this embodiment, the rolling and drying drum 1 of the tea milling machine A will be described. is the actual tea leaf temperature
Tea leaf temperature sensor 5 for measuring TT, hot air generator B
A hot air temperature sensor 6 is installed to measure the actual temperature T of the hot air supplied from the drying drum 1, and a load sensor 9 is installed in the weighing pool 2 on the drying drum 1 to detect the amount of tea leaves added. Generator B fan 1
A dry-bulb temperature sensor 7 and a wet-bulb temperature sensor 8 for measuring the dry-wet-bulb temperature of the surrounding air are installed near the air conditioner 5 . Motor 4 and fan 15 for driving the main shaft 3
The rotation speed of the drive motor 16 is changed by inverters 17 and 18 controlled by the control device C. The tea processing machine A and the hot air generator B described above are controlled by a control device C whose block diagram is shown in FIG. D, and data input keys 20 for dividing one rough rolling process into five stages and inputting tea leaf temperature (product temperature) set values TT _{1 to 5} set in advance for each of the five stages. It is also equipped with a 7-segment LED display 21 that selectively displays set values or actual measured values such as hot air temperature, air volume, spindle rotation speed, and tea leaf temperature. Therefore, to describe how to determine the optimal setting values for hot air temperature, air volume, and stage time for each preset stage of the rough rolling method in this embodiment, the tea leaves are The optimum temperature according to the ambient air condition and the nature of the tea leaves,
It receives hot air whose volume is adjusted. That is, the target tea leaf temperature TTm (1 mn) preset for each stage n, the temperature tdm of the air surrounding the hot air generating means determined by the wet and dry bulb measuring means,
From the wet bulb temperature twm, the optimum hot air temperature Tm can be determined using, for example, the following equation. From the relationship between wet and dry bulb temperature and vapor pressure, Pm = PWM - 0.5 (tdm - twm) ... In the above, Pm: Water vapor pressure of the surrounding air PWM: Saturated water vapor pressure of the surrounding air Transforming the above equation, Tm = TTm + 2 ( Pwm−Pm) ... In the above, Pwm: Saturated water vapor pressure at tea leaf temperature. The above PWM and Pwm are each calculated from the Coff-Gratch equation at the wet bulb temperature.
It can be obtained from twm and TTm. By substituting the expression into the expression, the following ′ expression is obtained. Tm = 2 (PWM - Pwm) + tdm - twm + TTm ...' Also, for example, if the number of stages n = 5 as shown in Table 1, the ratio C to the standard air volume according to the properties of tea leaves.
If set, the maximum air volume of the hot air generation means
Since Vmax can be known in advance, the maximum air volume
By dividing the ratio C of the first stage of the tea leaves with the largest ratio C of Vmax by the ratio C ₁ , the standard air volume V ₀ ( = Vmax÷C ₁・Mirume) is obtained, and the optimal air volume value V _{1 to 5} for each stage is obtained.
are V ₀ ×C ₁ , V ₀ ×C ₂ , V ₀ ×C ₃ , V ₀ ×C ₄ , V ₀ ×
It can be determined by C ₅ . When the number of stages n is not 5, Vm=V ₀ ×Cm (1 mn).

[Table] Furthermore, from the above-mentioned optimal hot air temperature Tm and reference air volume V ₀ , properties of the tea leaves to be added (for example, dry basis moisture content D), and input amount M, the optimal rough rolling time can be determined using, for example, the following formula. KT is required. KT=2787×D−100/D+100÷(Tm−ET ₀ )÷V ₀ ... In the above equation, ET ₀ is the temperature of the exhaust gas discharged after drying the tea leaves, and depending on the nature of the tea leaves, The settings can be made as shown in Table 2.

[Table] As mentioned above, since the reference air volume V ₀ is required to be used to the maximum capacity of the hot air generation means, this rough kneading time KT is determined by the nature of the tea leaves and the surrounding air hot air generation means. This is the shortest time considering all abilities. By dividing this coarse kneading time KT by the number of stages n, the optimal time for each stage is determined.
ST can be obtained. Therefore, the optimal hot air temperature TT _1~o , air volume V1 _~o , and stage time for each stage were determined as above.
Start the rough kneading process with ST as the set value. Each of the above setting values is optimal for drying tea leaves at a constant rate based on the properties of the tea leaves and the state of the surrounding air, so the tea leaves are stirred by the rough kneading means and their temperature reaches approximately the predetermined temperature TTm. It is exposed to hot air and undergoes constant drying. Therefore, even if the rough rolling process is carried out according to each set value without changing each set value in the middle of each step, the set values of the main elements are forced to apply to the existing change pattern for the conventionally input tea leaves. It is much easier to keep the tea leaves at a specified temperature than when the rough rolling process is performed for the first time.
It is possible to perform constant drying while maintaining the TTm. Even if the above settings are optimal at the beginning of the roughening process or at the beginning of each stage,
The properties of tea leaves vary widely, and there are slight internal errors, and the conditions of the surrounding air (temperature, humidity)
Since external errors occur due to changes, the initially optimal set values gradually become less optimal during the rough kneading process or during each stage. Following such a trend, even if the actual temperature of tea leaves matches the value set as optimal, the set value may not match the current situation due to the internal and external factors mentioned above. As a result, the actual temperature of the tea leaves gradually deviates from the optimum temperature, causing the tea leaves to become slightly dry or overly moist, resulting in a decline in the quality of the tea leaves. Become. In this example, the quality of tea leaves is
TT is measured by the tea leaf temperature sensor 5 installed in the drying drum 1, and the tea leaf temperature setting value for each process described above is determined.
TTm is compared with the above-mentioned actual measurement value TT, and each setting value is changed in stages so that the difference becomes smaller depending on the size and persistence of the difference.
The difference in tea leaf temperature that occurred as described above (TT-
TTm) and deviation from constant drying rate are eliminated,
Through the rough rolling process, the tea leaves can be extremely accurately maintained at the optimum temperature TTm and undergo constant drying. The above-mentioned stepwise change of each set value is preferably carried out as follows, for example, in which only the hot air temperature Tm and the air volume set value Vm are changed. (1) Actual value TT of tea leaf temperature is 0.3℃ higher than set value TTm
If it goes above or below, lower or raise the hot air temperature set value Tm by 5°C. (2) Actual tea leaf temperature value TT is 0.3℃ higher than set value TTm
or exceed the range of 1.0℃ for 2 minutes continuously, or
Or if it goes below, lower or raise it further by 5℃. (3) Actual value TT of tea leaf temperature is 1℃ higher than set value TTm
If it goes above or below, the hot air temperature set value Tm is lowered or raised by 5°C, and the air volume set value Vm is lowered or raised by 5%. If the temperature rises or falls above 1°C for 1 minute and 30 seconds, the temperature will be further lowered or raised by 5°C. By comparing (1) to (3) above, a more optimized set value is obtained, and by receiving the hot air adjusted to the set value, the tea leaves are extremely accurately adjusted to the optimal product temperature TTm at each stage. The drying process is maintained at a constant temperature without over-drying or over-wetting. Furthermore, to describe this embodiment in detail, the tea processing machine A shown in FIG. ³ /min. Therefore, the dry basis moisture content of the buds that can be seen by their properties is 400.
% of tea leaves are coarsely ground when the dry bulb temperature td of the ambient air is 20℃ and the wet bulb temperature tw is 16℃.The tea leaf temperature set value TT for each stage of 1 to 5 _{is 1 to 5.}
Considering the improvement of quality rather than the efficiency of drying, we set it at a low common temperature of 35℃, and since the input tea leaves are the buds that can be seen,
From Table 3 shown below, calculate the amount W to be fed into the tea leaf drying drum 1.
120 kg/time, and input it into the control device C in advance by operating the input key 20 along with the dry basis moisture content D.

[Table] Based on the above input, the fourth
Optimum settings were obtained as shown in the table.

【table】

〔Effect of the invention〕

The tea manufacturing and rough rolling method according to the present invention divides one rough rolling process into multiple or many stages, and adjusts the temperature, air volume, spindle rotation speed, etc. of hot air as appropriate so that the tea leaf temperature is maintained at a predetermined temperature. In the tea manufacturing and roughening method, the optimum hot air temperature is determined based on the tea leaf temperature set value set in advance in each of the above steps and the wet and dry bulb temperature of the ambient temperature of the hot air generating means, and the optimum hot air temperature is determined based on the standard air volume according to the properties of the tea leaves. The optimal amount of hot air is determined based on the preset ratio and the standard air volume based on the maximum air volume of the hot air generating means, and then the optimal roughening is determined based on the above-mentioned optimal hot air temperature and standard air volume, the nature of the tea leaves to be added, and the amount of tea leaves to be added. Determine the process time, then divide the optimum roughening process time by the number of stages to obtain the time for each stage, set each set value as the set value for each stage time, and set each set value during the process. Therefore, while roughening the tea leaves, the tea temperature is actually measured at each stage, and the set value of the tea leaf temperature and the above-mentioned measured value are compared, and the temperature of the hot air is adjusted according to the difference.
The set value of the air volume was adjusted so that the difference mentioned above was reduced, and the temperature of the tea leaves was controlled to the optimum level. Since the product is dried using hot air set to an optimal value depending on the condition, the temperature of the product is maintained at a predetermined temperature from beginning to end, allowing for almost constant drying. Even if the temperature of the product deviates from the optimum temperature due to internal or external factors, each setting value of the hot air is adjusted based on the deviation, so the deviation is kept to a minimum and the temperature of the product is extremely high. Not only is the temperature precisely maintained at a predetermined optimum temperature, but drying is carried out at a very constant rate. Therefore, the quality of the coarsely rolled leaves and, ultimately, the tea will be significantly improved. Furthermore, since the capacity of the hot air generating means is utilized to the maximum, the capacity for rough rolling of tea leaves can be significantly improved.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; Fig. 1 is an overall explanatory diagram of a tea processing machine and a hot air generator, Fig. 2 is a block diagram of the control means, and Fig. 3 is an illustration of actual measured values and set values of tea leaf temperature. FIG. 3 is a diagram showing the relationship between changes and changes in set values of hot air temperature and air volume. A: Tea milling machine, B: Hot air generator, 1: Rolling and drying barrel, 2: Measuring pool, 3: Main shaft, 5: Tea leaf temperature sensor, 6: Hot air temperature sensor, 7: Dry bulb temperature sensor, 8: Wet bulb Temperature sensor, 9: Weighing sensor,
TT, TT _1-o : Actual value of tea leaf temperature, set value, td,
td _1-o : Dry bulb temperature of ambient air, tw, tw _1-o : Wet bulb temperature of ambient air, T _1-o : Set value of hot air temperature, V ₀ ,
V _1-o , Vmax: Standard air volume of hot air, air volume setting value, maximum air volume of hot air generation means.

Claims (1)

[Claims] 1. Tea manufacturing and roughening in which one rough rolling process is divided into multiple or many stages, and the temperature, air volume, spindle rotation speed, etc. of hot air are adjusted by control means so that the tea leaf temperature is maintained at a predetermined optimum temperature. In the method, for each of the above steps, the optimum hot air temperature is determined based on the preset value of the tea leaf temperature and the wet and dry bulb temperature of the air surrounding the hot air generating means, and the optimum hot air temperature is determined based on the standard air volume according to the properties of the tea leaves. The optimal amount of hot air is determined based on the preset ratio and the standard air volume based on the maximum air volume of the hot air generating means, and then the optimal roughening is determined based on the above-mentioned optimal hot air temperature and standard air volume, the nature of the tea leaves to be added, and the amount of tea leaves to be added. Determine the process time, then divide the optimum roughening process time by the number of stages to obtain the time for each stage, set each of the above set values as the set values for each of the above stage times, and set each of the above settings during the process. In addition to roughly rolling the tea leaves according to the value, the tea leaf temperature is actually measured in each of the above steps, the set value of the tea leaf temperature and the above-mentioned measured value are compared, and the temperature and air volume of the above-mentioned hot air are set according to the difference. A tea manufacturing and roughening method characterized by adjusting the value so that the above-mentioned difference becomes small to maintain and control the tea leaf temperature at an optimum temperature.