A three-phase green tea-fixing device and green tea-fixing method

Abstract

The present invention discloses a three-phase green-fixing device and a green-fixing method thereof, including a drum, the drum is equipped with a hot air generator, a hot air releaser, a steam generator and a steam releaser, the drum is provided with a heating device to heat the inner wall of the drum, the steam releaser is arranged in the inner cavity of the drum, and it includes a steam pipe connected to the steam generator, the steam pipe entering the inner cavity of the drum is shorter than the length of the drum, and the steam pipe entering the inner cavity of the drum is provided with a steam release hole; the hot air releaser is arranged in the inner cavity of the drum, and it includes a hot air pipe connected to the hot air generator, the hot air pipe entering the inner cavity of the drum is shorter than the length of the drum, and the hot air pipe entering the inner cavity of the drum is provided with a hot air release hole. The present invention optimizes and integrates and innovates traditional drum green-fixing, steam green-fixing, hot air green-fixing, etc., gives full play to the advantages of each green-fixing, avoids weaknesses, and realizes the comprehensive improvement of green-fixing leaves in terms of color, aroma and uniformity.

Description

[0001] The present application is a divisional application of a three-phase combined fixing device and fixing method, and the application date of the original application document is 2018-06-01, the application number is 201810554203.3, and the name of the invention is a three-phase combined fixing device and fixing method. Technical Field

[0002] The invention belongs to the technical field of food processing, relates to tea processing technology, and in particular to a three-phase tea-withering device and a tea-withering method. Background Art

[0003] Tea is a kind of addictive and healthy beverage. With the continuous improvement of people's living standards and consumption concepts, the appearance, color, aroma, taste and other internal flavors of tea have become the primary conditions for consumers to choose tea. The killing process is the key to obtaining excellent quality, which has a significant impact on the color, aroma and taste of the finished product. The principle is to use high temperature and high humidity to destroy the oxidases in the fresh tea leaves, so that the polyphenols are oxidized as little as possible to obtain a mellow and refreshing tea soup taste, while removing the green odor in the fresh leaves, developing the tea fragrance, and maintaining the unique bright green color of green tea, forming the excellent color, aroma, taste and other sensory qualities of the finished tea.

[0004] At present, the main methods of tea withering used in production include steam withering, hot air withering, drum withering, microwave withering, etc. Among them, drum withering is the most widely used because of its advantages of good quality of withered leaves, low investment cost, continuous production, and convenient matching with subsequent processes. According to different heating methods, drum withering can be divided into multiple types such as wood-fired, coal-fired, gas-fired, and electric heating. With the improvement of people's living standards and the continuous improvement of hygiene requirements, electric drum withering has gradually been favored by tea farmers and production enterprises, occupying a large market share. Traditional electric drum withering uses electric heating tubes as heating sources. After the electric heating tubes are heated, they heat the air, and the air then transfers the heat energy to the steel cylinder. The heat energy utilization rate of this process is low, and the traditional electric drum withering uses thermocouple temperature sensors, which have slow temperature response and large temperature changes of the steel cylinder, resulting in further loss of heat energy; at the same time, due to the limitation of the heating method, the uniformity of the temperature of the entire steel cylinder is relatively poor, which in turn affects the stability and consistency of the quality of the withered leaves.

[0005] Steam killing is a method that uses the penetration of high-temperature steam to passivate the enzyme activity in fresh leaves. It has the characteristics of fast and uniform killing, and is beneficial to maintaining the color of the finished product. However, when steam is used alone for killing green leaves, the steam will accumulate on the finished product, causing the moisture content of the finished product to reach more than 90%. On the one hand, it affects the permeation of aromatic substances. On the other hand, improper handling will cause the color of the finished product to turn yellow and have a watery smell. In addition, the subsequent dehydration process of the finished product has high requirements for equipment, which further increases the processing cost.

[0006] High-temperature hot air fixing is a method that uses high-temperature hot air to inactivate enzyme activity. During operation, high-temperature hot air is sent into the fixing chamber through the hot air duct. When the fresh leaves enter the drum, the tumbling fresh leaves are fully in contact with the hot air. Due to the large temperature difference between the fresh leaves and the hot air, the heat is quickly transferred from the hot air to the fresh leaves, thereby quickly inactivating the enzyme activity and completing the fixing operation. This method has the advantages of uniform and thorough fixing, no burnt edges or bursting points, better color, and a more lasting aroma of the finished product, but the high and sharp aroma characteristics are not prominent.

[0007] Chinese patent literature discloses a drum fixing machine CN201910421622.4, which includes a furnace body, a furnace cover, a base, a drum rotatably arranged on the base, a driving motor and a reduction device; the furnace body is fixedly arranged on the base, the furnace cover is hinged on the furnace body to form a cylindrical furnace cavity, the drum is located in the cylindrical furnace cavity and extends out of the furnace cavity at both ends, one end of the drum is fixedly provided with a toothed disc and chain-connected to the reduction device, the reduction device is provided with a belt and connected to the driving motor, and a plurality of spiral guide plates extending from one end of the drum wall to the other end are provided on the inner wall of the drum; a rotating shaft is provided at the middle bottom end of the bracket, and rollers are rotatably provided at both ends of the rotating shaft.

[0008] The withering method described in this patent only uses the drum withering method. Although compared with the traditional manual withering method, this patent has the advantages of high output and low labor cost; however, this technical solution still contains the following technical defects: 1. Low thermal energy utilization rate and slow temperature response; 2. The temperature of the steel cylinder changes greatly, resulting in further loss of heat energy; 3. At the same time, due to the relatively poor temperature uniformity in the entire withering cylinder, the stability and consistency of the quality of the withered leaves are affected.

[0009] Chinese patent document CN201621363264.4 discloses a hot air steam drum fixing machine, specifically a hot air steam drum fixing machine, including a fixed outer cylinder, a thermal insulation interlayer, an exhaust port, an air intake layer, a steam pipe, a hot air pipe, a partition and a rotating device. The fixed outer cylinder is divided into a fixing area and a heat dissipation area. The fixing area is provided with a thermal insulation interlayer and an air intake layer, and the thermal insulation interlayer and the air intake layer are separated by a partition. The thermal insulation interlayer is arranged outside the air intake layer, and an exhaust port is arranged on the thermal insulation interlayer. The steam pipe and the hot air pipe are connected to the air intake layer, and a rotating device is arranged in the fixed outer cylinder.

[0010] The patent describes a hot air and steam two-phase combined method for fixing the green leaves, that is, a method of fixing the green leaves by mixing high-temperature hot air and steam. The fixing chamber is a drum, and the fresh leaves rotate and roll forward in the drum, while fixing the green leaves. The main defects are as follows: 1. The hot air and steam are mixed first, and the heat of the mixed gas is then transmitted to the fixing chamber over a long distance, rather than being mixed directly in the fixing chamber. Therefore, although there is a heat preservation layer, there is also a situation where the heat is lost quickly and the temperature drops, resulting in a deviation in the fixing and enzyme inactivation effect, and is not conducive to the stimulation of aroma; 2. The drum fails to heat up, and the advantage of the drum fixing in improving the aroma quality of the finished product is not brought into play; 3. The heat of the mixed gas enters from one end of the drum and exits from the other end, without considering the details of uniform gas and heat distribution, and there is a temperature difference phenomenon.

[0011] In view of the shortcomings of the above-mentioned prior art, there is an urgent need for a three-phase tea withering equipment and a tea withering method used therein, which can integrate the three existing tea withering methods into one and simultaneously have the advantages of the three tea withering methods, thereby further improving the quality of tea withering. Summary of the invention

[0012] In order to solve the inherent idea that traditional withering only adopts a single mode, the present invention optimizes and integrates traditional drum withering, steam withering, hot air withering, etc., and organically integrates the solid, liquid and gas three-phase withering methods to give full play to the advantages of each withering and avoid weaknesses, thereby achieving comprehensive improvement in color, aroma and uniformity of the withered leaves.

[0013] In order to achieve this invention object, the present invention adopts the following technical scheme: a three-phase fixing equipment, including a drum, one end of the drum is a leaf feeding device, the other end of the drum is a leaf outlet end, the drum is equipped with a hot air generator, a hot air releaser, a steam generator and a steam releaser, the drum is provided with a heating device to heat the inner wall of the drum, the steam releaser is arranged in the inner cavity of the drum, and includes a steam pipe communicated with the steam generator, the part of the steam pipe entering the inner cavity of the drum is shorter than the length of the drum, and the part of the steam pipe entering the inner cavity of the drum is provided with a steam release hole; the hot air releaser is arranged in the inner cavity of the drum, and includes a hot air pipe communicated with the hot air generator, the part of the hot air pipe entering the inner cavity of the drum is shorter than the length of the drum, and the part of the hot air pipe entering the inner cavity of the drum is provided with a hot air release hole;

[0014] The drum is provided with a three-stage electromagnetic heating system to achieve three-stage heating, and the heating lengths of the three stages are distributed in a ratio of 4:3:3 starting from the blade inlet end;

[0015] The present application can break through the inherent idea of ​​the traditional single mode of withering, and organically integrate and innovate the three withering methods of solid phase, liquid phase and gas phase, so as to give full play to the unique advantages of the three in the withering operation, namely, the drum solid phase withering is beneficial to the aroma, the steam liquid phase withering has good color and uniformity, and the hot air withering is uniform and thorough, without burnt edges or bursting points, and the aroma lasts for a long time.

[0016] Preferably, the steam pipe enters the inner cavity of the drum from the blade inlet end, and steam release holes are distributed on the steam pipe, and the apertures of the steam release holes decrease from large to small from the blade inlet end to the blade outlet end;

[0017] The hot air duct enters the inner cavity of the drum from the blade outlet end, and hot air release holes are distributed on the hot air duct, and the apertures of the hot air release holes decrease from large to small from the blade inlet end to the blade outlet end;

[0018] The steam pipe is extended to 2 / 3 of the drum length, so that a large amount of high-temperature steam is distributed at the front 2 / 3 of the drum cavity;

[0019] Through innovative designs in structure, delivery pipes, apertures and other details, the withering operation is high first and low later, enzymes are killed in the early stage, and quality is improved in the later stage. While achieving uniform and thorough withering, the color, aroma and other quality attributes of the withered leaves are effectively improved. In the design of the delivery pipe, a steam delivery pipe is implanted in the front section. With the characteristics of strong steam penetration and fast enzyme inactivation, the enzyme activity can be quickly inactivated during rolling withering. The steam content is high in the first 1 / 3, and the steam gradually decreases to 2 / 3, forming a decreasing steam distribution. The hot air delivery pipe is implanted from the back end, which is mainly used to enhance the aroma of the withered leaves and retain the greenness of the withered leaves on the basis of enzyme inactivation.

[0020] Preferably, the length of the hot air duct is 150 mm shorter than the length of the drum;

[0021] The diameter of the steam pipe is in the range of 25-30 mm, the diameter of the hot air pipe is in the range of 200-250 mm, and the distance between the steam pipe and the hot air pipe is maintained between 100-150 mm.

[0022] Preferably, the steam release hole and the hot air release hole are circular holes, and the maximum diameter of the steam release hole does not exceed 5 mm, and the minimum diameter is not less than 1 mm;

[0023] The maximum diameter of the hot air release hole is no more than 5 mm, and the minimum diameter is no less than 1 mm.

[0024] The hole diameters on the conveying pipe are designed from large to small, so that the relative diameters of the hot air release holes and the steam release holes are the same or basically the same. It is mainly used to ensure that when the steam and hot air enter the withering chamber, the hot air density and the steam density can maintain their relative consistency, so that the quality uniformity of the withered leaves is better.

[0025] Preferably, the withering equipment is equipped with a dehumidification device at the leaf outlet end; the dehumidification device is used to adjust the humidity of the withering environment in the drum.

[0026] A specific dehumidification device is installed at the leaf outlet end. On the one hand, it can make the high-temperature steam and high-temperature hot air in the withering chamber distributed from front to back. On the other hand, it ensures that the environmental humidity is not high in the later stage of withering to prevent the quality of the finished product from deteriorating.

[0027] Preferably, the drum has a diameter of 80 cm and a length of 455 cm.

[0028] Preferably, the leaf feeding device is funnel-shaped, and the lower end of the leaf feeding device is connected to the inner cavity of the drum.

[0029] Preferably, the heating device adopts electromagnetic heating, so that the drum can be heated in three stages, and the three stages of heating adopt a setting in which the temperature is first high and then low.

[0030] The basic module of drum killing based on electromagnetic heating ensures that the drum can achieve three-stage heating. After electromagnetic heating, the temperature of each drum is stable and uniform, and the temperature fluctuation range is ±2°C. Through three-stage heating, the temperature is set high first and then low, which can truly meet the purpose of first killing enzymes and then improving quality. At the same time, through the organic integration with steam and hot air, this effect can be further enhanced.

[0031] A method for fixing tea leaves using the three-phase fixing device, comprising the following steps:

[0032] (1) heating the roller, and setting the temperatures of the three sections of the roller to 250° C.-260° C., 230° C.-240° C., and 190° C. respectively;

[0033] (2) Start the steam generator to allow steam to flow through the steam pipe and fill the inner cavity of the drum;

[0034] (3) Start the hot air generator, set the temperature to 190°C, and let the hot air flow through the hot air duct to fill the entire fixing chamber;

[0035] (4) At the same time, the single cycle of fixing is adjusted to 75±3s by the speed of the drum, and the speed is not less than 18 rpm;

[0036] (5) After the three phases of drum temperature, hot air temperature and steam are balanced, fresh leaves are added from the leaf feeding device.

[0037] Preferably, the subsequent process flow of the withered leaves is: rolling - initial baking - sufficient fire - aroma enhancement.

[0038] The benefits of the present invention are:

[0039] 1. Break through the inherent thinking of the traditional single mode of fixing green tea, and organically integrate and innovate the three fixing methods of solid phase, liquid phase and gas phase, so as to give full play to the unique advantages of the three in the fixing operation, that is, the drum solid phase fixing green tea is beneficial to the aroma, the steam liquid phase fixing green tea has good color and uniformity, and the hot air fixing green tea is uniform and thorough, without burnt edges and burst points, and the aroma is long-lasting;

[0040] 2. Through innovative designs in structure, delivery pipes, apertures and other details, the withering operation is high first and low later, enzymes are killed in the early stage, and quality is improved in the later stage. While achieving uniform and thorough withering, the color, aroma and other quality attributes of the withered leaves are effectively improved. In the design of the delivery pipe, a steam delivery pipe is implanted in the front section. With the characteristics of strong steam penetration and fast enzyme inactivation, the enzyme activity can be quickly inactivated during rolling withering. The steam content is high in the first 1 / 3, and the steam gradually decreases to 2 / 3, forming a decreasing steam distribution. The hot air delivery pipe is implanted from the rear end, which is mainly used to enhance the aroma of the withered leaves and retain the greenness of the withered leaves on the basis of enzyme inactivation.

[0041] 3. The apertures on the conveying pipe are designed from large to small, so that the relative diameters of the hot air release holes and the steam release holes are the same or basically the same. This is mainly used to ensure that when the steam and hot air enter the withering chamber, the hot air density and the steam density can maintain their relative consistency, so that the quality of the withered leaves is more uniform.

[0042] 4. The basic module of drum killing based on electromagnetic heating ensures that the drum can achieve three-stage heating. After electromagnetic heating, the temperature of each drum is stable and uniform, and the temperature fluctuation range is ±2°C. Through three-stage heating, the temperature is set high first and then low, which can truly meet the purpose of first killing enzymes and then improving quality. At the same time, through the organic integration with steam and hot air, the effect is further enhanced.

[0043] 5. A specific dehumidification device is installed at the leaf outlet end. On the one hand, it can make the high-temperature steam and high-temperature hot air in the withering chamber distributed from front to back. On the other hand, it ensures that the environmental humidity is not high in the later stage of withering to prevent the quality of the finished product from deteriorating. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 It is a schematic diagram of the structure of the three-phase fixing equipment;

[0046] Figure 2The present invention discloses a method for using the three-phase fixing equipment of the present invention.

[0047] 1—drum 2—heating device 3—hot air generator 4—hot air duct 5—circular small hole 6—steam generator 7—steam duct 8—leaf inlet device 9—leaf outlet 10—dehumidification device DETAILED DESCRIPTION

[0048] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0049] The present invention is further described in conjunction with embodiments.

[0050] like Figure 1 A three-phase tea-fixing device includes a drum with a diameter of 80 cm and a length of 455 cm. The front end of the drum is a leaf inlet end, and a leaf inlet device is installed at the leaf inlet end. The leaf inlet device is a funnel that conducts through the inner cavity of the drum and is installed on the upper side of the drum. The other end of the drum is a leaf outlet end, and the drum is equipped with a hot air generator, a hot air releaser, a steam generator and a steam releaser.

[0051] The leaf feeding device is funnel-shaped, and the lower end of the leaf feeding device is communicated with the inner cavity of the drum.

[0052] The drum is equipped with a heating device to achieve three-stage heating. The heating lengths of the three sections are distributed in a ratio of 4:3:3 starting from the blade inlet. Different temperatures can be set for the three heating sections. The specific structure is the same as the common segmented heating device on the market.

[0053] The steam pipe enters the inner cavity of the drum from the blade inlet end, and its length reaches 2 / 3 of the drum length. There are circular holes on the steam pipe, which are steam release holes. The diameter of the steam release holes decreases from the blade inlet end to the blade outlet end. The maximum hole diameter does not exceed 5mm, the minimum diameter is not less than 1mm, and the hole diameter is 5mm.

[0054] The hot air duct enters the drum cavity from the blade outlet end, and its length is 150mm shorter than the drum length. There are circular holes on the hot air duct, which are hot air release holes. The hot air release hole diameter decreases from the blade inlet end to the blade outlet end. The maximum diameter of the hot air release hole does not exceed 5mm, the minimum diameter is not less than 1mm, and the hole diameter is 5mm.

[0055] The diameter of the steam pipe is 25mm, the diameter of the hot air pipe is 200mm, and the distance between the steam pipe and the hot air pipe is 100mm. There is no fixed value for the diameter of the steam pipe and the diameter of the hot air pipe. Usually, the diameter of the steam pipe is 25-30mm, and the diameter of the hot air pipe is 200-250mm. It is adjusted according to the difference in drum models to achieve the rapid and uniform distribution of steam and hot air in the drum. After many tests, it was found that the steam pipe and the hot air pipe diameter within the above range have the best effect on tea withering, and the hot air and steam are relatively evenly distributed. The distance between the steam pipe and the hot air pipe is kept between 100-150mm, and it can be adjusted within this range according to the process requirements. Too small or too large a distance will affect the temperature and air density of the intermediate steam and hot air.

[0056] A dehumidification device is installed at the leaf outlet end of the drum. On the one hand, it can make the high-temperature steam and high-temperature hot air in the withering chamber distributed from front to back. On the other hand, it ensures that the environmental humidity is not high in the later stage of withering to prevent the quality deterioration of the finished product.

[0057] When the three-term fixing device of the present application is used, the drum 1 is first heated by the heating device 2, and the heating temperatures of the three heating areas of the drum 1 from the leaf inlet end to the leaf outlet end are set to 250°C-260°C, 230°C-240°C, and 190°C respectively; then the steam generator 6 is started, and the steam generated by the steam generator 6 is distributed throughout the inner cavity of the drum 1 through the steam pipe. Since the steam pipe occupies 2 / 3 of the length of the drum 1 and cooperates with the special arrangement of the steam release hole on the steam pipe, the steam content in the front 1 / 3 of the drum 1 is The steam gradually decreases to 2 / 3, forming a decreasing steam distribution; then the hot air generator 3 is turned on, and the hot air temperature is set to 190°C, so that the hot air passes through the hot air duct and fills the entire withering chamber, so that the tea leaves have been inactivated, and the aroma of the withered leaves is further enhanced, and the greenness of the withered leaves is retained; finally, the single cycle of withering is adjusted to 75±3s through the speed of the drum 1, and the speed is not less than 18 rpm; after the drum temperature, hot air temperature and steam are balanced, fresh leaves are put into the leaf feeding device 8.

[0058] The following Examples 1 and 2 both use a killing green equipment with a drum diameter of 80 cm, a length of 455 cm, a steam pipe diameter of 25 mm, a hot air pipe diameter of 200 mm, and a distance of 100 mm between the steam pipe and the hot air pipe.

[0059] Example 1

[0060] The raw materials selected for a three-phase withering method are: 50 kg of green leaves of the Fuding Dabai variety and a tenderness of single bud to 1 bud and 1 leaf.

[0061] The specific implementation is as follows:

[0062] (1) The drum is heated by electromagnetic means, and the temperatures of the three sections of the drum are set to 250°C, 230°C, and 190°C respectively; at the same time, the steam generating device is started, and the steam is allowed to pass through the conveying pipe to fill the withering cavity, and the effect is focused on the front 2 / 3 of the withering cavity; the hot air generating system is started, and the temperature is set to 190°C, so that the hot air passes through the conveying pipe to basically fill the entire withering cavity (slightly shorter at the front end); at the same time, the single cycle of withering is adjusted to 75±3s and the speed is 20 rpm by the speed of the drum. After the drum temperature, hot air temperature, steam, etc. are balanced, fresh leaves can be added from the leaf feeding device.

[0063] (2) The same raw materials as in (1) were used as the test object, and the 60-type drum tea-withering machine, which is currently widely used in production, was used as the control (6CST-60 tea drum tea-withering machine produced by Zhejiang Shangyang Machinery Co., Ltd.). The withering temperature was set to 250°C, the single cycle time was 75±3s, and the speed was 20 rpm. After the temperature was balanced, fresh leaves were fed from the leaf feeding device.

[0064] Example 2

[0065] The raw materials selected for a three-phase withering method are: the variety is Fuding Dabai, and the tenderness is 1 bud 1 leaf to 1 bud 2 leaves, 50 kg of green leaves that are just beginning to unfold.

[0066] (1) The drum is heated by electromagnetic means, and the temperatures of the three sections of the drum are set to 260°C, 240°C, and 190°C respectively; at the same time, the steam generating device is started, and the steam is allowed to pass through the conveying pipe to fill the withering cavity, and the effect is focused on the front 2 / 3 of the withering cavity; the hot air generating system is started, and the temperature is set to 190°C, so that the hot air passes through the conveying pipe to basically fill the entire withering cavity (slightly shorter at the front end); at the same time, the single cycle of withering is adjusted to 75±3s and the speed is 20 rpm by the speed of the drum. After the three phases of the drum temperature, hot air temperature, and steam are balanced, fresh leaves can be added from the leaf feeding device.

[0067] (2) The same raw materials as in (1) were used as the test object, and the 60-type drum tea-withering machine, which is currently widely used in production, was used as the control (6CST-60 tea drum tea-withering machine produced by Zhejiang Shangyang Machinery Co., Ltd.). The withering temperature was set to 260°C, the single cycle time was 75±3s, and the speed was 20 rpm. After the temperature was balanced, fresh leaves were added from the leaf feeding device.

[0068] The quality comparison of the fixing process is as follows:

[0069] A systematic analysis was conducted on the quality of the in-process products, the physical and chemical properties, and the physical and chemical properties of the finished products in Example 1 and Example 2. As can be seen from Table 1, whether it is a single bud-1 bud 1 leaf raw material with high tenderness, or a fresh leaf with slightly lower tenderness, the three-phase withered sample is tender green, fresh, and has a strong fragrance. It has better appearance color and freshness than the traditional drum withered product, and the aroma quality is also better. The results of chemical composition detection show that the amino acid, soluble total sugar, and chlorophyll content of the three-phase withered leaves are significantly higher than those of the traditional drum withered, which provides a good material basis for subsequent operations, thereby ensuring the excellent quality of the aroma, color, and other qualities of the finished tea. In terms of production efficiency, because the three-phase withered adopts a combination of operations in various ways, the efficiency is about doubled compared to the single drum withered.

[0070] Table 1 Analysis of product characteristics under different killing treatments

[0071]

[0072] The sensory evaluation results of finished teas with different withering treatments are shown in Table 2. The results show that because the three-phase withering method is more scientific and accurate in the design and regulation of the operation process and parameter details, and integrates the inherent advantages of different withering technologies, under the same subsequent process conditions, the sensory scores of the finished tea samples processed by the three-phase withering method are significantly higher than those of the traditional drum withering tea samples (the trend is the same under the two tenderness conditions): among them, the appearance color and soup color are obviously better, and the internal flavors such as aroma and taste are slightly higher than those of traditional drum withering.

[0073] Table 2 Sensory evaluation results of finished teas with different withering treatments

[0074]

[0075] The subsequent process flow of withered leaves is: rolling - initial baking - sufficient fire - aroma enhancement.

[0076] The sensory evaluation scoring criteria are: appearance × 20% + soup color × 20% + aroma × 25% + taste × 25% + leaf bottom × 10%.

[0077] In addition, the terms "upper", "lower", "inner", "outer", "front", "rear" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. Unless otherwise specifically stated, the relative steps, numerical expressions and values ​​of the components and steps described in these embodiments do not limit the scope of the present invention.

[0078] Of course, the above description is only a specific embodiment of the present invention and is not intended to limit the scope of implementation of the present invention. All equivalent changes or modifications made according to the structure, characteristics and principles described in the patent application scope of the present invention should be included in the patent application scope of the present invention.

[0079] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

[0080] The above-mentioned embodiment only expresses one implementation mode of the present invention, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A three-phase fixing device, comprising a drum, one end of which is a leaf feeding device, and the other end of which is a leaf outlet. The drum is equipped with a hot air generator, a hot air releaser, a steam generator and a steam releaser, characterized in that: The drum is provided with a heating device to heat the inner wall of the drum, the steam releaser is provided in the inner cavity of the drum, and includes a steam pipe communicated with the steam generator, the portion of the steam pipe entering the inner cavity of the drum is shorter than the length of the drum, and the portion of the steam pipe entering the inner cavity of the drum is provided with a steam release hole; the hot air releaser is provided in the inner cavity of the drum, and includes a hot air pipe communicated with the hot air generator, the portion of the hot air pipe entering the inner cavity of the drum is shorter than the length of the drum, and the portion of the hot air pipe entering the inner cavity of the drum is provided with a hot air release hole; The drum is provided with a three-stage electromagnetic heating system to achieve three-stage heating, and the heating lengths of the three stages are distributed in a ratio of 4:3:3 starting from the blade inlet end; The steam pipe enters the inner cavity of the drum from the blade inlet end, and steam release holes are distributed on the steam pipe, and the diameter of the steam release holes decreases from the blade inlet end to the blade outlet end; The hot air duct enters the inner cavity of the drum from the blade outlet end, and hot air release holes are distributed on the hot air duct, and the apertures of the hot air release holes decrease from large to small from the blade inlet end to the blade outlet end; The steam pipe is extended to 2 / 3 of the drum length, so that a large amount of high-temperature steam is distributed at the front 2 / 3 of the drum cavity; The steam release hole and the hot air release hole are circular holes, the maximum diameter of the steam release hole is no more than 5 mm, and the minimum diameter is no less than 1 mm; The maximum diameter of the hot air release hole is no more than 5 mm, and the minimum diameter is no less than 1 mm.

2. A three-phase fixing device according to claim 1, characterized in that: The length of the hot air duct is 150 mm shorter than the length of the drum, the diameter range of the steam duct is 25-30 mm, the diameter range of the hot air duct is 200-250 mm, and the distance between the steam duct and the hot air duct is maintained between 100-150 mm.

3. A three-phase fixing device according to claim 1, characterized in that: The withering equipment is equipped with a dehumidifying device at the leaf outlet end; the dehumidifying device is used to adjust the humidity of the withering environment in the drum.

4. The three-phase fixing equipment according to claim 1, characterized in that: The drum has a diameter of 80 cm and a length of 455 cm.

5. The three-phase fixing equipment according to claim 1, characterized in that: The leaf feeding device is funnel-shaped, and the lower end of the leaf feeding device is communicated with the inner cavity of the drum.

6. The three-phase fixing equipment according to claim 1, characterized in that: The heating device adopts electromagnetic heating, so that the drum can be heated in three stages, and the three stages of heating adopt a setting in which the temperature is first high and then low.

7. A method for fixing tea leaves using a three-phase fixing device according to any one of claims 1 to 6, characterized in that: Here are the steps: (1) heating the roller, and setting the temperatures of the three sections of the roller to 250° C.-260° C., 230° C.-240° C., and 190° C. respectively; (2) Start the steam generator to allow steam to flow through the steam pipe and fill the inner cavity of the drum; (3) Start the hot air generator, set the temperature to 190°C, and let the hot air flow through the hot air duct to fill the entire fixing chamber; (4) At the same time, the single cycle of fixing is adjusted to 75±3s by the speed of the drum, and the speed is not less than 18 rpm; (5) After the three-phase equilibrium of the drum temperature, hot air temperature and steam is reached, fresh leaves are fed into the leaf feeding device; The subsequent process of withering leaves is: rolling - initial baking - sufficient fire - aroma enhancement.

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