A method for drying scented tea

Abstract

The application discloses a kind of jasmine tea drying method, comprising the following steps: step one: after separating, jasmine tea wet base is evenly laid on sieve tray with 2-5cm thickness, is placed in controllable closed loop drying bin of temperature and humidity, and the dry environment temperature is set to 50~70 DEG C, relative humidity is 10%~30%;Step two: the wet hot air in drying bin is blown to the jasmine tea wet base to be dried, and the wet hot air with flower fragrance is formed into fragrance with flower fragrance through condensing component, and flows into recovery bin;Step three: the fragrance in recovery bin is generated by microwave atomizer, and the fragrance is blown into drying bin by air blower, tea leaf absorbs aroma while also taking away part of wet hot air, to form "hot-cold" airflow and "dry-wet" airflow closed circulation;Step four: equipment continues to run 20min~60min, until tea reaches dry enough.The method of the application is to form "hot-cold" airflow and "dry-wet" airflow closed circulation, which can improve the fragrance of jasmine tea.

Description

Technical Field

[0001] This invention relates to a method for drying flower tea. Background Technology

[0002] Scented teas, such as jasmine tea, require more than ten processing steps to blend the aroma of tea and flowers, resulting in a fresh and elegant floral fragrance and a mellow and refreshing taste. The re-firing of wet tea leaves during processing is a highly technical process, requiring the evaporation of excess moisture while preserving the absorbed floral aroma to the maximum extent possible, creating a fresh and rich floral quality. Currently, the drying (re-firing) method used in scented tea production is mainly hot air drying, which has the following problems: difficulty in precisely controlling the temperature and humidity of the drying environment, resulting in a large loss rate of the total aroma concentration of jasmine tea (60%), long drying time, and high energy consumption. Summary of the Invention

[0003] The main objective of this invention is to provide a method for drying flower tea.

[0004] The technical solution adopted by this invention to solve its technical problem is: The method for drying flower tea includes the following steps: Step 1: Spread the wet tea leaves after flower separation evenly on a sieve tray to a thickness of 2-5cm, and place them in a closed-loop drying chamber with controlled temperature and humidity. Set the drying environment temperature to 50℃~70℃ and the relative humidity to 10%~30%. Step 2: The hot, dry airflow inside the drying chamber blows onto the wet jasmine tea leaves to be dried, and then the hot, humid airflow with floral fragrance is passed through the condensation component to form a fragrant liquid with floral fragrance, which flows into the recovery chamber. Step 3: The aroma in the recovery chamber is converted into fragrant mist by an ultrasonic atomizer. The fragrant mist is blown into the drying chamber by a blower. The tea leaves absorb the aroma and at the same time take away some of the hot and humid airflow, forming an alternating cycle of "hot-cold" airflow and "dry-humid" airflow. Step 4: Continue running steps 2 and 3 for 20 to 60 minutes until the tea leaves are fully dried.

[0005] Preferably, in step two, the hot and humid airflow is regulated by a temperature and humidity sensor in the heat pump main unit compartment.

[0006] Preferably, in step two, a heat pump main unit compartment is provided at the bottom of the drying chamber. The airflow in the drying chamber passes through the heating components in the heat pump main unit compartment and is blown by the fan into the mesh ventilation opening towards the wet jasmine tea blanks to be dried.

[0007] Preferably, in step two, the heat pump main unit compartment is equipped with a first heating component and a second heating component.

[0008] Preferably, the heat pump main unit compartment is equipped with a condensation unit, which includes a condensation component. A first connecting pipe is provided below the condensation component, and the port of the first connecting pipe is directly below the condensation component. The other end of the first connecting pipe is connected to the fragrance recovery chamber. The fragrance recovery chamber is equipped with an ultrasonic atomizer and an exhaust fan. After the fragrance is atomized, it returns to the heat pump main unit compartment through a second connecting pipe and is then blown into the drying working chamber by the blower.

[0009] Preferably, the condensing unit further includes a high-pressure section of the compressor, a heater, and a low-pressure section of the compressor; the condensing assembly, the high-pressure section of the compressor, the heater, and the compressor are connected in sequence, and the low-pressure section of the compressor is then connected to the condensing assembly.

[0010] Preferably, the condenser assembly of the condenser unit is located between the first heating assembly and the second heating assembly, and the heater is located between the second low-temperature heating assembly and the air inlet duct in the drying chamber; the airflow from the drying chamber first passes through the first heating assembly, then through the condenser assembly for condensation, then through the second heating assembly of the heat pump main unit, then through the heater, and then enters the drying chamber again.

[0011] Preferably, an air inlet pipe and an air outlet pipe are provided on both sides of the drying chamber, and a blower is provided in the air inlet pipe. The blower delivers air from the heat pump main unit chamber to the drying working chamber.

[0012] Preferably, a temperature sensor and a humidity sensor are respectively installed above the blower in the air inlet duct.

[0013] Preferably, a mesh ventilation opening is provided at the junction of the air inlet duct, the air outlet duct, and the drying chamber.

[0014] In this invention, “about” means that the numerical range can vary by ±10%.

[0015] Compared with the prior art, this technical solution has the following advantages: 1. The method of the present invention uses a heat pump main unit to regulate the temperature and humidity of the drying chamber. Under low temperature and low humidity conditions, the airflow is directionally regulated from dry heat to humid heat to cold fragrance to hot fragrance, so that the moisture and aroma in the jasmine tea base are evaporated by heat, condensed and recovered, and then heated to impart fragrance. This method can both evaporate moisture and retain aroma substances.

[0016] 2. The aroma content of the dried jasmine tea produced by this invention is higher than that of the traditional hot air drying method, reaching 49.621 ug / g at 50℃ and 20% humidity. The content of the main aroma components is also higher, and the aroma substances are better preserved, thus improving the quality of jasmine tea.

[0017] 3. In the method of this invention, a portion of the humid air is discharged while the other portion is circulated, allowing for the reuse of heat. This method shortens drying time by approximately 50% compared to traditional hot air drying methods, saves energy, and also reduces the amount of flowers needed for subsequent drying processes, thus lowering production costs. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Figure 1 This is a schematic diagram of the flower tea drying device of the present invention.

[0020] Figure 2 This is a schematic diagram of the electrical control system of the flower tea drying device of the present invention.

[0021] In the picture: 1-Drying chamber, 1-1 Air inlet duct, 1-2 Air outlet duct, 1-3 Dehumidification outlet, 1-4 Air inlet 2-Heat pump main unit compartment, 3-Fragrance recovery compartment, 4-Mesh vent, 5-Control switch, 6-Touch control panel, 7-Stainless steel mesh screen, 8-Heater, 9-Compressor high-pressure section, 10-First low-temperature heating component, 11-Condensing component, 12-Blower, 13-Compressor low-pressure section, 14-Temperature sensor, 15-Humidity sensor, 16-Exhaust fan, 17-Ultrasonic atomizer, 18-First connecting pipe, 19-Second connecting pipe, 20-Second low-temperature heating component, 21-Humidity sensor Detailed Implementation

[0022] Please refer to Figure 1 and Figure 2 A flower tea drying device includes a drying chamber 1, which is divided into multiple layers by a stainless steel mesh screen 7. Vertically arranged ventilation ducts are located on both sides of the drying chamber 1. In this embodiment, the left side is the air inlet duct 1-1, and the right side is the air outlet duct 1-2. A mesh ventilation opening 4 is provided at the junction of the air inlet duct 1-1, the air outlet duct 1-2, and the drying chamber. A control switch 5 is located next to the mesh ventilation opening 4. A touch-sensitive control panel 6 is located on the front. A hygrometer 7 is provided between the upper and lower layers. The hygrometer 7 is preferably located at the bottom of the partition layer. A dehumidification outlet 1-3 is provided at the top of the air outlet duct 1-2.

[0023] A heat pump main unit compartment 2 is located at the bottom of the drying chamber 1. Both the air inlet duct 1-1 and the air outlet duct 1-2 are connected to the heat pump main unit compartment 2. A blower 12 is installed at the lower end of the air inlet duct 1-1 to deliver air from the heat pump main unit compartment 2 to the drying chamber 1. A temperature sensor 14 and a humidity sensor 15 are respectively installed above the blower 12 on the air inlet duct 1-1. An air inlet 1-4 is located near the right side of the heat pump main unit compartment 2.

[0024] The side of the heat pump main unit compartment 2 near the outlet end of the air outlet duct 1-2 ( Figure 1 (Right side in the middle) A first low-temperature heating component 10 is provided, and a second low-temperature heating component 20 is provided to the left of the first low-temperature heating component 10. A condensing unit is also provided in the heat pump main unit compartment 2. The condensing unit includes a condensing component 11, a high-pressure section 9 of the compressor, a heater 8, and a low-pressure section 13 of the compressor. The condensing component 11, the high-pressure section 9 of the compressor, the heater 8, and the low-pressure section 13 of the compressor are connected in sequence; the low-pressure section 13 of the compressor is then connected to the condensing component 11. The condensing component 11 of the condensing unit is located between the first heating component 10 and the second low-temperature heating component 20, and the heater 8 is located on the side near the inlet end of the air inlet duct. Figure 1 (The middle is the left side). The airflow from the drying chamber 1 first passes through the first heating component 10, then through the condenser component 11, then through the second low-temperature heating component 20 of the heat pump main unit chamber 2, and then through the heater 8.

[0025] A fragrance recovery chamber 3 is located outside the drying chamber 1. A first connecting pipe 18 is located below the condenser assembly 11, with its port facing directly below the condenser assembly 11. The other end of the first connecting pipe 18 is connected to the fragrance recovery chamber 3. An ultrasonic atomizer 17 is installed inside the fragrance recovery chamber 3, and an exhaust fan 16 is located at the top. One end of a second connecting pipe is located inside the fragrance recovery chamber 3, and the other end is located inside the heat pump main unit chamber 2. After atomization, the fragrance returns to the heat pump main unit chamber 2 through the second connecting pipe 19.

[0026] The second connecting pipe 19 is preferably located close to the heater 8 within the heat pump main unit compartment 2.

[0027] The use of the flower tea drying device is as follows: (1) Spread the jasmine tea wet cake after flower separation evenly on the stainless steel sieve tray 7 with a thickness of 2-5cm, put it into the drying working chamber 1, and set the drying environment temperature to 50℃-70℃ and the relative humidity to 10%-30% on the touch control panel 6.

[0028] (2) Turn on the control switch 5. The temperature and humidity required are regulated by the temperature and humidity sensor in the drying working chamber 1. After the blower 12 starts working, an air circulation is formed in the drying device, such as heat pump main unit chamber 2, blower 12, air inlet pipe 1-1, drying working chamber 1, air outlet pipe 1-2, and heat pump main unit chamber 2.

[0029] In this process, the airflow passes through the first low-temperature heating element 10, then the second low-temperature heating element 20, and finally the heater 8 within the heat pump main unit compartment 2. The airflow is heated to approximately 40°C in the first low-temperature heating element 10, then to approximately 50°C in the second low-temperature heating element 20, and finally to approximately 90°C in the heater 8. The dry, hot airflow is blown from the blower 12 through the inlet duct 1-1 onto the jasmine tea leaves to be dried. The fragrant, moist airflow passes through the outlet duct 1-2 and flows to the condenser 11, forming a fragrant liquid. This fragrant liquid flows into the recovery chamber 3 via the first connecting pipe 18. After passing through the condenser 11, the airflow is reheated by passing through the first low-temperature heating element 10.

[0030] (3) The aroma in the recovery chamber 3 is generated into a fragrant mist by the ultrasonic atomizer 17. The fragrant mist is directed by the exhaust fan 16 through the second connecting pipe 19 to the heat pump main unit chamber 2, and then blown into the drying working chamber 1 by the blower 12. While the tea leaves absorb the aroma, they also take away some of the hot and humid airflow, forming an alternating cycle of "hot-cold" airflow and "dry-humid" airflow. Excess moisture can also be discharged from the recovery chamber 3.

[0031] (4) When the humidity detected by the hygrometer 7 is higher than the predetermined humidity, the exhaust ports 1-3 remain open to discharge some of the hot and humid airflow. At the same time, another part of the hot and humid airflow enters the circulation downwards; the aroma in this downward part of the hot and humid airflow is continuously condensed and collected. When the humidity drops to the predetermined level, the exhaust ports 1-3 are closed, and the aroma re-enters the heat pump main unit compartment and is then sent to the working chamber for circulation. The equipment runs continuously for 20 to 60 minutes until the tea leaves are fully dried.

[0032] Example 1

[0033] 10 kg of freshly picked jasmine tea leaves, after flower separation, are evenly spread on a stainless steel sieve tray to a thickness of 3 cm and placed in a closed-loop drying chamber with controlled temperature and humidity. The drying environment is set at 60℃, relative humidity at 20%, and drying time at 20 minutes, resulting in a moisture content of 6.70%. The airflow passes through the drying working chamber 1, the condenser (recovery chamber), and the heat pump main unit chamber 2, forming a cycle of "dry hot airflow - humid hot airflow (humid airflow with floral fragrance) - humid cold airflow (cool fragrance dew with floral fragrance) - dry hot airflow (slightly humid airflow with floral fragrance)". Once the drying time is completed and the tea leaves are fully dry, the equipment stops operating. After drying, the jasmine tea sample was analyzed by HS-SPME combined with GC-MS, with ethyl decanoate as the internal standard. The total volatile components reached 44.429 ug / g, linalool (lily of the valley aroma) content was 4.082 ug / g, benzyl acetate (with pear-like fruity and fresh aroma) content was 6.053 ug / g, benzoic acid leaf ester (green aroma) content was 4.383 ug / g, methyl anthranilate (with grape-like aroma) content was 3.015 ug / g, and α-farnesene (with fresh floral aroma) content was 12.057 ug / g.

[0034] Example 2

[0035] 10 kg of freshly picked jasmine tea leaves, after flower separation, are evenly spread on a stainless steel sieve tray to a thickness of 3 cm and placed in a closed-loop drying chamber with controlled temperature and humidity. The drying environment is set at 50℃, relative humidity at 20%, and drying time at 30 minutes, resulting in a moisture content of 7.15%. The airflow passes through the working chamber, the condenser (recovery chamber), and the heat pump main unit chamber, forming a cycle of "dry hot airflow - humid hot airflow (humid airflow with floral fragrance) - humid cold airflow (cool fragrance dew with floral fragrance) - dry hot airflow (slightly humid airflow with floral fragrance)". Once the drying time is completed and the tea leaves are fully dry, the equipment stops operating. After drying, the jasmine tea sample was analyzed by HS-SPME combined with GC-MS, with ethyl decanoate as the internal standard. The total volatile components reached 49.621 ug / g, linalool (lily of the valley aroma) content was 4.634 ug / g, benzyl acetate (with pear-like fruity and fresh aroma) content was 6.836 ug / g, benzoic acid leaf ester (green aroma) content was 6.226 ug / g, methyl anthranilate (with grape-like aroma) content was 3.341 ug / g, and α-farnesene (with fresh floral aroma) content was 10.872 ug / g.

[0036] Comparative Example 1

[0037] 10 kg of wet jasmine tea leaves, after flower separation, were evenly spread on a sieve tray with a thickness of 3 cm and placed in a hot air dryer. The drying temperature was set to 60℃, and the drying time was 39 min, resulting in a moisture content of 6.25%. After drying, the jasmine tea sample was analyzed using HS-SPME combined with GC-MS. With ethyl decanoate as an internal standard, the total volatile components reached 42.358 ug / g, linalool (lily of the valley aroma) content was 4.251 ug / g, benzyl acetate (with pear-like fruity and fresh aroma) content was 4.675 ug / g, benzoic acid leaf ester (green aroma) content was 4.710 ug / g, methyl anthranilate (with grape-like aroma) content was 3.195 ug / g, and α-farnesene (with fresh floral aroma) content was 11.550 ug / g.

[0038] Comparative Example 2 10 kg of wet jasmine tea leaves, after flower separation, were evenly spread on a sieve tray with a thickness of 3 cm and placed in a hot air dryer. The drying temperature was set at 50℃ and the drying time was 66 min, resulting in a moisture content of 6.90%. After drying, the jasmine tea sample was analyzed using HS-SPME combined with GC-MS. With ethyl decanoate as an internal standard, the total volatile components reached 42.711 ug / g, linalool (lily of the valley aroma) content was 4.344 ug / g, benzyl acetate (with pear-like fruity and fresh aroma) content was 6.367 ug / g, benzoic acid leaf ester (green aroma) content was 5.520 ug / g, methyl anthranilate (with grape-like aroma) content was 3.080 ug / g, and α-farnesene (with fresh floral aroma) content was 9.560 ug / g.

[0039] The above description is merely a preferred embodiment of the present invention, and therefore should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of the patent and the contents of the specification should still fall within the scope of the present invention.

Claims

1. The method for drying flower tea includes the following steps: Step 1: Spread the flower tea leaves, after flower separation, evenly on a sieve tray to a thickness of 2cm-5cm. Place the tray in a drying chamber with controlled temperature and humidity, setting the drying environment temperature to 50℃~70℃ and the relative humidity to 10%~30%. Step Two: Hot, dry airflow from the drying chamber is blown onto the wet jasmine tea leaves to be dried. The fragrant, humid airflow then passes through a condenser to form a fragrant dew, which flows into a dew collection chamber. The drying chamber has inlet and outlet ducts on both sides. A blower is installed in the inlet duct to deliver air from the heat pump main unit compartment to the drying chamber. The heat pump main unit compartment also contains a first low-temperature heating component and a second low-temperature heating component. The condenser of the condenser unit is located between the first and second low-temperature heating components, and the heater is located between the second low-temperature heating component and the inlet duct in the drying chamber. The airflow from the drying chamber first passes through the first low-temperature heating component, then is condensed by the condenser, then passes through the second low-temperature heating component in the heat pump main unit compartment, then through the heater, and finally enters the drying chamber. Step 3: The aroma in the aroma recovery chamber is generated into a mist by an ultrasonic atomizer. The mist is blown into the drying chamber by an exhaust fan. The tea leaves absorb the aroma and also carry away some of the hot and humid airflow, forming an alternating cycle of "hot-cold" and "dry-humid" airflow. Step 4: Continue running steps 2 and 3 for 20 to 60 minutes until the tea leaves are fully dried.

2. The method for drying flower tea as described in claim 1, characterized in that: In step two, the hot and humid airflow is regulated by temperature and humidity sensors in the heat pump unit compartment.

3. The method for drying flower tea as described in claim 1, characterized in that: In step two, the airflow in the drying chamber passes through the heating components in the heat pump main unit chamber and is blown by the blower into the mesh ventilation openings to the wet jasmine tea blanks to be dried.

4. The method for drying flower tea as described in claim 1, characterized in that: The heat pump main unit compartment is equipped with a condensation unit, which includes a condensation component. A first connecting pipe is located below the condensation component, with the port of the first connecting pipe facing the bottom of the condensation component. The other end of the first connecting pipe is connected to the fragrance recovery chamber. The fragrance recovery chamber is equipped with an ultrasonic atomizer and an exhaust fan. After the fragrance is atomized, it returns to the heat pump main unit compartment through a second connecting pipe and is then blown into the drying working chamber by the blower.

5. The method for drying flower tea as described in claim 4, characterized in that: The condensing unit also includes a high-pressure section of the compressor, a heater, and a low-pressure section of the compressor; the condensing assembly, the high-pressure section of the compressor, the heater, and the low-pressure section of the compressor are connected in sequence, and the low-pressure section of the compressor is then connected to the condensing assembly.

6. The method for drying flower tea as described in claim 1, characterized in that: Temperature and humidity sensors are installed above the air supply duct on the air supply duct.

7. The method for drying flower tea as described in claim 1, characterized in that: Mesh ventilation openings are installed at the junction of the air inlet duct, the air outlet duct, and the drying chamber.

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