Tea leaf drying system and drying method

Abstract

The invention relates to the technical field of tea leaf drying. The embodiment of the invention provides a tea leaf drying system and a drying method. The tea leaf drying system comprises a drying box internally provided with a drying cavity, one end of the drying cavity is provided with an air inlet, and the other end of the drying cavity is provided with an air outlet; the drying frame is arranged in the drying cavity and located between the air inlet and the air outlet; the multiple air inlets are arranged in the circumferential direction of the drying cavity at intervals, the direction from the ends where the air inlets are located to the ends where the air outlets are located is the first direction, and the opening direction of at least one air inlet is inclined relative to the radial direction of the drying cavity and the first direction. And the air flow entering the drying cavity forms a spiral air flow. The technical problem that the utilization efficiency of hot air far away from tea leaves in the hot air circulation process in a drying system in the prior art is not high is solved.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to the technical field of tea drying, and in particular, to a tea drying system and a drying method. Background Art

[0002] The air ducts of various small tea drying systems are usually directly equipped with fans, which send hot air from the air inlet through the fan. The hot air passes through the tea leaves to be dried and is discharged from the air outlet. The fan controls it to re-enter the air inlet to form a cycle. A certain amount of gas is discharged during the dehumidification stage, but there is also fresh air to supplement it, which does not affect the circulating air volume.

[0003] The Chinese invention patent application with application number 201911136275.7 discloses an energy-saving dryer for tea, specifically a device that can reduce energy consumption by recycling waste heat from hot air and heat the tea evenly.

[0004] The existing dryer has a heating device installed in the drying box to bake the tea leaves, and realizes air circulation in the drying box in combination with the air duct. Specifically, a dehumidification layer is installed on the air inlet duct, so that the hot air circulates through the dehumidification layer to discharge the moisture and then re-enter the circulation, and the residual heat of the hot air that has circulated once is effectively utilized; the drying plate is driven by a rotating motor to rotate, so that the tea leaves are evenly heated.

[0005] During the drying process of the existing dryer, heat transfer mainly occurs on the surface of the tea leaves to be dried. The hot air close to the tea leaves no longer has the heat exchange capacity after contacting the surface of the tea leaves for heat exchange, but some of the hot air far away from the tea leaves does not participate in the heat exchange. The unheated hot air will lose part of the heat energy after passing through the dehumidification layer, resulting in low utilization efficiency of the hot air. In addition, a heating device is directly set in the drying box to bake the tea leaves, which may easily cause the temperature in the drying box to be too high, resulting in the tea leaves being roasted badly. Summary of the invention

[0006] To solve at least one of the above problems, the present invention provides a tea drying system and a drying method, which solves the technical problem of low utilization efficiency of hot air away from tea leaves during hot air circulation in the drying system in the prior art.

[0007] According to one aspect of the present invention, there is provided a tea drying system, comprising: a drying box, wherein a drying cavity is provided inside the drying cavity, wherein an air inlet is provided at one end of the drying cavity, and an air outlet is provided at the other end; A drying rack, which is arranged in the drying cavity and located between the air inlet and the air outlet; There are a plurality of air inlets, which are arranged at intervals along the circumference of the drying cavity. The first direction is from the end where the air inlet is located to the end where the air outlet is located. The opening direction of at least one of the air inlets is inclined relative to the radial direction of the drying cavity and the first direction, so that the airflow entering the drying cavity forms a spiral airflow.

[0008] Optionally, the drying cavity is a cylindrical channel, and a plurality of the air inlets are arranged in pairs, and each pair of the air inlets are arranged opposite to each other and have opposite opening directions.

[0009] Optionally, the drying cavity is a cylindrical channel, and the angle between the opening direction of the inclined air inlet and the radial direction of the drying cavity is α, and α is an acute angle; The angle between the opening direction of the inclined air inlet and the first direction is β, and the angle β is 65°~75°.

[0010] Optionally, a plurality of pairs of the air inlets are arranged at intervals along the circumferential direction on the side wall of the drying cavity or the bottom of the drying cavity.

[0011] Optionally, also include: A cyclone, which is arranged at at least one of the air inlets, comprises: A rotating seat, which is annular and arranged on the inner wall of the air inlet, and whose inner wall has an annular guide groove; The fan blade has at least two blades, and one end of the blade away from the center is slidably arranged in the annular guide groove.

[0012] Optionally, the drying rack is rotatably disposed in the drying cavity; further comprising: A driving motor is arranged on the drying box to drive the drying rack to rotate.

[0013] Optionally, the rotation direction of the drying rack is opposite to the rotation direction of the spiral airflow.

[0014] Optionally, also include: The ultrasonic generator is used to emit ultrasonic waves to the tea leaves on the drying rack.

[0015] Optionally, also include: The adsorbent is arranged on the inner wall of the drying cavity and at the air outlet, and has a through hole, which is connected to the air outlet; the opening size of the through hole gradually decreases along the first direction.

[0016] Optionally, also include: There are a plurality of trays which are arranged on the drying rack at intervals along the first direction, and the supporting surface of the trays is mesh-shaped and used for supporting tea leaves, and there is a gap between two adjacent trays.

[0017] Optionally, also include: The first heater is arranged in the drying box and is used for heating the adsorption element.

[0018] Optionally, also include: A circulation channel, one end of which is connected to the plurality of air inlets, and the other end of which is connected to the air outlet; A first fan, which is arranged on the circulation channel and located at one end close to the air inlet, and is used to blow air toward the air inlet; The second fan is arranged on the circulation channel and located at one end close to the air outlet, and is used for blowing air in a direction away from the air outlet.

[0019] Optionally, also include: a regenerator, which is arranged on the circulation channel and located between the first fan and the second fan; A fresh air channel, which is connected to the circulation channel near one end of the air inlet through the regenerator; a dehumidification channel, which is connected to the circulation channel near one end of the air outlet through the heat regenerator; The regenerator enables the airflow flowing out of one end of the air outlet in the circulation channel to complete heat exchange with the airflow in the fresh air channel; The second heater is arranged between the first fan and the air inlet.

[0020] Optionally, the first direction is along the vertical direction, the air outlet is located at the top of the drying cavity, and further includes: A condensed water collecting member is arranged in the drying cavity and below the air outlet, and comprises: A conical cover, the top of which faces the air outlet and the lower end of which is a condensate guide surface; A conical ring cover is arranged below the conical cover, with the conical part facing the air outlet, the condensate guide surface leading to the upper end surface of the conical cover, and the conical ring cover has a water collecting trough leading to the outside of the drying cavity.

[0021] Optionally, the condensate collection member further comprises: The guide piece is annular and bent toward the center of the circle as a whole to form an arc-shaped guide surface. It is arranged between the conical cover and the conical ring cover, forms a flow channel with the conical cover, and has a drainage hole between the guide piece and the conical ring cover.

[0022] According to another aspect of the present invention, a tea drying method is provided, using the tea drying system, the drying method comprising the following steps: S1: Loading, placing tea leaves on a drying rack in a drying cavity; S2: Drying: air is blown into the drying cavity through the air inlet, and the wind passes through the cyclone to form spiral wind; this spiral wind blows toward the tea leaves to complete the drying.

[0023] If the spiral wind blows towards the tea leaves in a clockwise direction, the drying rack rotates counterclockwise under the drive motor; or if the spiral wind blows towards the tea leaves in a counterclockwise direction, the drying rack rotates clockwise under the drive motor; S3: Circulation, the humid air flow enters the circulation channel from the air outlet, exchanges heat with the fresh air through the regenerator, and part of it is discharged through the dehumidification channel, and the rest is heated by the second heater under the action of the first fan and returns to the drying cavity through the air inlet; S4: Condensate collection and treatment: Condensate condensed near the air outlet by the hot air flow is collected by the condensate collection component. The water droplets first attach to the conical cover, enter the flow channel through the guide surface, and then enter the water collection tank of the conical ring cover through the drainage hole and then discharge from the system.

[0024] S5: Dehumidification and regeneration of the adsorbent. During drying, the adsorbent absorbs the water vapor rising from the edge of the tray through the holes. After the hygroscopic filler is saturated, the first heater is started to heat it to a specified temperature (such as 50℃ - 80℃), so that the water in the filler evaporates and is discharged with the air flow to achieve regeneration.

[0025] The beneficial effects of the embodiments of the present disclosure are: In the present invention, by changing the direction of the air inlet and adding a cyclone, a spiral airflow is generated. The spiral airflow will first contact and exchange heat with the surface of the tea leaves placed on the drying rack. The airflow moves in a spiral shape and shuttles through the tea leaves layer, so that the moisture on the surface of the tea leaves is gradually evaporated. The temperature of the hot air after heat exchange near the surface of the tea leaves will be reduced. The hot air far away from the surface of the tea leaves will gradually approach the tea leaves to participate in heat exchange due to the drive of the spiral airflow. Compared with the traditional linear airflow drying method, the utilization rate of the hot air is improved. BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the description of the embodiments of the present disclosure. Obviously, the drawings described below are only some exemplary embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained based on the contents of the exemplary embodiments of the present disclosure and these drawings without creative work.

[0026] Figure 1 This is a schematic diagram of the overall internal structure of a tea drying system in one embodiment of the present disclosure; Figure 2 for Figure 1 A schematic diagram of the internal structure of the embodiment of the invention in a transverse cross section from the air inlet; Figure 3It is a schematic diagram of the internal structure of a vertical cross section of an obliquely arranged air inlet in one embodiment of the present disclosure; Figure 4 for Figure 2 A schematic diagram of the structure of the inlet inclination angle at position A in the embodiment; Figure 5 for Figure 3 A schematic diagram of the structure of the inlet inclination angle at position B in the embodiment; Figure 6 This is a schematic diagram of the three-dimensional structure of a cyclone in another embodiment of the present disclosure; Figure 7 It is a schematic structural diagram of a cyclone in a front view in another embodiment of the present disclosure; Figure 8 A schematic diagram of the internal airflow state of a tea drying system with a baffle in another embodiment of the present disclosure; Fig. 9 This is a schematic diagram of the opening state of the heat regenerator of the tea drying system in another embodiment of the present disclosure; Fig.10 for Figure 1 A schematic diagram of the structure of the condensate collecting member at position C in the embodiment; In the figure: 1. Drying box, 101. Drying cavity, 102. Air inlet, 103. Air outlet, 104. First direction; 2. drying rack, 201. driving motor, 202. tray; 3. cyclone, 301. rotating seat, 302. annular guide groove, 303. fan blade, 304. blade, 4. Ultrasonic generator; 5. Adsorption member, 501, through hole; 6. The first heater; 7. circulation channel, 701. first fan, 702. second fan, 703. regenerator, 704. fresh air channel, 705. dehumidification channel, 706. second heater; 8. Condensate collecting member, 801. Conical cover, 802. Conical ring cover, 803. Water collecting trough, 804. Guide member, 805. Circulation channel, 806. Drain hole; 9. Baffle. DETAILED DESCRIPTION

[0027] The present disclosure is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present disclosure, rather than to limit the present disclosure.

[0028] In order to simplify the drawings, only the parts related to the disclosure are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically shown, or only one of them is marked. In this article, "one" not only means "only one", but also means "more than one", and "several" includes "two" and "more than two".

[0029] In this document, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this disclosure can be understood according to specific circumstances.

[0030] In the present disclosure, unless otherwise expressly specified and limited, a first feature being “above” or “below” a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being “above”, “above”, and “above” a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0031] In the description of this embodiment, terms such as "up", "down", "left", and "right" and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present disclosure.

[0032] In addition, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0033] Embodiment 1 like Figure 1 to Figure 3 As shown, it shows a tea drying system in one embodiment of the present disclosure.

[0034] See first Figure 1 , Figure 1The figure is a schematic diagram of the overall structure of the tea drying system in one embodiment of the present disclosure. The drying box 1 is a rectangular box or a cylindrical box as a whole. Optionally, a heat-insulating layer may be provided inside the drying box 1, and a lining may be provided inside the heat-insulating layer. A drying cavity 101 for placing tea leaves for drying is formed inside the drying box 1. A plurality of air inlets 102 are provided at one end of the drying cavity 101, and an air outlet 103 is provided at the other end. The first direction 104 is the overall flow direction of the airflow in the drying cavity, which can be regarded as a columnar trajectory formed from the end where the air inlet 102 is located to the end where the air outlet 103 is located.

[0035] See also Figure 2 , Figure 2 for Figure 1 Schematic diagram of the internal structure of the embodiment of the invention from the transverse cross section of the air inlet. The multiple air inlets 102 are connected via a circulating air duct for unified ventilation. Optionally, the multiple air inlets 102 are arranged in an annular manner at the bottom of the drying cavity 101, and the opening direction of at least one air inlet 102 is inclined relative to the radial direction of the drying cavity. Figure 2 , wherein the opening may be oriented in a direction tangential to the cross section of the columnar channel formed in the first direction 104, or may be oriented in a direction tangential to the cross section of the columnar channel formed in the first direction 104. Figure 3 The opening direction of other air inlets 102 can be toward the radial direction of the drying cavity, or toward the air outlet 103. The inclined air inlet 102 guides the airflow in the drying cavity 101 into a spiral airflow along the first direction 104.

[0036] See also Figure 1 The spiral airflow will firstly contact and exchange heat with the surface of the tea leaves placed on the drying rack 2. The airflow moves in a spiral shape and shuttles through the tea leaves layer, so that the moisture on the surface of the tea leaves is evaporated quickly. The temperature of the hot air will be lowered after heat exchange near the surface of the tea leaves. The hot air far away from the surface of the tea leaves will gradually approach the tea leaves to participate in heat exchange due to the driving of the spiral airflow. Compared with the traditional linear airflow drying method, the utilization rate of the hot air is improved.

[0037] See also Figure 1 and Figure 3The drying rack 2 is arranged in the drying cavity 101, between the air inlet 102 and the air outlet 103. The drying rack 2 is used to place a tray 202, and the tray 202 is used to place tea leaves to be dried. An evaporation channel is formed between the drying rack 2 and the side wall of the drying cavity 101. Since the tray 202 on the drying rack 2 has tea leaves to be dried, its wind blocking effect is increased. Therefore, the air circulation rate of the evaporation channel is higher than the circulation rate of the location of the drying rack 2. When the spiral airflow flows through the drying rack 2, part of the airflow overflows laterally from the gap between adjacent trays 202 on the drying rack 2 and flows to the evaporation channel, and the other airflow passes through the tea leaves on the tray 202 and continues to flow to the next tray 202. Since the air circulation rate of the evaporation channel is high, a high-speed airflow is formed, while the airflow velocity in the drying rack 2 is slow, the pressure at the evaporation channel becomes smaller, and then the humid airflow in the drying rack 2 is sucked out. The moisture after heat exchange will gradually move toward the air outlet 103 along with the air flow, and finally be discharged from the air outlet 103.

[0038] By forming a spiral airflow, the problem of low utilization efficiency of hot air far away from tea leaves in the hot air circulation process in the drying system in the prior art is effectively solved. In addition, due to the high flow rate of the evaporation channel and the slow flow of the drying rack 2, the spiral airflow can better absorb the humid airflow after heat exchange, making it easier for the unheated airflow to contact the tea leaves, providing an efficient and stable drying system for tea leaves.

[0039] In some examples, the drying cavity 101 may be a cylindrical channel, and the corresponding drying box 1 may be rectangular or cylindrical, wherein the number of air inlets may be 2, 4, 6 or 8.

[0040] For example, Figure 2 As shown, the drying box 1 is cylindrical, and the drying cavity 101 is also a cylindrical channel. The shape of the cylindrical channel helps to form a stable spiral airflow. A plurality of air inlets 102 are arranged at intervals along the circumference of the cylindrical channel, and the air inlets 102 are arranged in pairs. Optionally, the number of air inlets is 4, one pair of which is arranged horizontally opposite to each other, and the opening directions are opposite, both facing the axis of the cylindrical channel, and can interact with each other. Due to the opposite airflow directions, a tendency of rotation will begin to be generated in the drying cavity 101.

[0041] Another pair can be arranged horizontally opposite to each other, with the opening directions opposite and tilted relative to the radial direction of the cylindrical channel. Since the inner wall of the cylindrical channel is arc-shaped, the airflow deviating from the radial direction of the cylindrical channel flows along the inner wall of the drying cavity 101, and finally forms a spiral airflow, based on which a more stable spiral airflow can be formed, further improving the use efficiency of hot air.

[0042] In some examples, the air inlet 102 may be tilted in the horizontal direction and may also be tilted in the vertical direction. For example, Figure 2-5 As shown, Figure 4 for Figure 2 In the embodiment of FIG. 1 , the angle between the opening direction of the inclined air inlet 102 and the radial line of the drying cavity 101 is α, and the angle is an acute angle. Optionally, when α is set to 30°, the hot air entering from the air inlet 102 will impact the internal space of the drying cavity 101 at a specific oblique angle, and interact with the hot air entering from another opposite air inlet 102, and initially build the prototype of the spiral airflow.

[0043] in Figure 5 for Figure 3 In the embodiment of the structural schematic diagram of the inclination angle of the air inlet at B, the angle between the opening direction of the inclined air inlet 102 and the first direction 104 is β. The optional angle of β is 65°~75°, and optionally, β is 70°. The hot air entering from the air inlet 102 will enter the drying cavity 101 along an oblique path of 70° to the first direction 104, so that the airflow entering the drying cavity 101 can accurately form a stable and evenly distributed spiral airflow. Similarly, α and β can exist at the same time to ensure that the hot air can fully cover the tea leaves on the drying rack 2 and improve the drying efficiency and uniformity.

[0044] In some examples, some air inlets 102 are arranged at intervals along the circumference of the side wall of the drying cavity 101. For example, two pairs of air inlets 102 can be arranged evenly distributed on the same circumference of the side wall. Each pair of air inlets 102 is arranged oppositely, and their opening directions are opposite, and the angle between the opening direction of the obliquely arranged air inlet 102 and the radial line of the drying cavity 101 is α (optionally α is 30°), and the angle between the opening direction of the obliquely arranged air inlet 102 and the first direction 104 is β (optionally β is 70°). Such a layout and angle design enables the hot air entering from the side wall air inlet 102 to form a spiral airflow in the drying cavity 101, and due to the synergistic effect of multiple pairs of air inlets 102, the spiral airflow can evenly cover the cross-section of the entire drying cavity 101, ensuring that tea leaves placed at different positions on the drying rack 2 can receive hot air.

[0045] Alternatively, the air inlets 102 may be arranged at intervals along the circumference of the bottom of the drying cavity 101. For example, three pairs of air inlets 102 are arranged in a circular pattern at the bottom. The bottom air inlets 102 are also designed in a relative and inclined manner, and their angle parameters cooperate with the side wall air inlets 102, so that the hot air entering from the bottom can also generate a spiral airflow, thereby enhancing the fluidity and uniformity of the hot air in the drying cavity 101.

[0046] In some examples, in order to enable the airflow of the air inlet to rise from the bottom of the drying rack 2 instead of directly entering the evaporation channel, a baffle is added above the air inlet. The baffle is annular and can divide the drying cavity 101 into an air inlet cavity and a working cavity, and the evaporation channel is located in the working cavity. Due to the obstruction of the annular baffle, the airflow can only flow along the space below the baffle to the bottom of the drying rack 2, and then gradually rise from the gap of the tray 202 of the drying rack 2 to enter the working cavity, forming an airflow path from bottom to top, avoiding the direct impact on the evaporation channel to cause airflow turbulence and uneven heat exchange.

[0047] In this embodiment, the drying rack 2 is located in the drying cavity 101, between the air inlet 102 and the air outlet 103. The drying rack 2 is constructed of a sturdy and heat-resistant metal frame, and a multi-layer support structure for placing the tray 202 is designed inside the frame. The door of the drying box 1 is opened (not shown in the figure), and the trays 202 are placed in the support structure in turn, and a reasonable spacing of 8-10 cm is maintained between each layer of trays 202. The tray 202 is made of a stainless steel mesh material with good air permeability so that the hot air can smoothly penetrate the tray 202 to exchange heat with the tea leaves.

[0048] Before the tea leaves are dried, the tea leaves to be dried are evenly spread on the tray 202. Depending on the type of tea leaves, the thickness of the tea leaves is controlled to be between 2 and 5 cm. For example, for the delicate Biluochun tea leaves, the thickness of the tea leaves can be controlled to be between 2 and 3 cm; while for the Pu'er raw tea leaves 304 with relatively thick leaves, the thickness of the tea leaves can be appropriately increased to 4 to 5 cm. Alternatively, 5 to 10 kg of tea leaves are spread evenly on each tray 202.

[0049] When the tea drying system is started, the external heater delivers hot air to the air inlets 102 on the side walls and / or the bottom of the drying cavity 101 through the circulation channel 7 .

[0050] The hot air entering from the side wall air inlets 102, due to their special relative arrangement and angle setting, interact with each other and form the main part of the spiral airflow in the drying cavity 101. The airflow spirals along the first direction 104 toward the air outlet 103, and in the process of moving forward, it contacts and exchanges heat with the tea leaves on the upper layer of the drying rack 2. At the same time, if the bottom is provided with an air inlet 102, the hot air entering from the bottom air inlet 102 also forms a spiral rising airflow, fully exchanges heat with the tea leaves on the bottom layer, and gradually merges into the overall spiral airflow.

[0051] When the airflow flows through the drying rack 2, part of the airflow will overflow laterally from the gap between adjacent trays 202 on the drying rack 2, and flow to the evaporation channel formed between the drying rack 2 and the side wall of the drying cavity 101. Since the tea leaves are placed on the drying rack 2 to increase the wind blocking effect, and the air circulation rate of the evaporation channel is relatively high, a high-speed airflow is formed in the evaporation channel. According to the Bernoulli principle, the pressure here becomes smaller, thereby generating a pressure difference, which sucks out the airflow containing more moisture in the drying rack 2, so that the hot and humid air around the tea leaves can be discharged to the external environment in time.

[0052] After the humid airflow is sucked out from the evaporation channel, it is finally discharged from the air outlet 103 at the other end of the drying cavity 101 as the overall airflow circulates. The external hot air blower continues to deliver hot air to the air inlet 102 to maintain a stable spiral airflow environment and a good drying atmosphere in the drying cavity 101 until the tea leaves reach a predetermined drying standard, such as a certain percentage of moisture content.

[0053] Embodiment 2 See also Figure 1~Figure 2 and Figures 6 and 7 , Figure 1 and Figure 2 It is shown that the cyclone 3 is arranged on the inner wall of any air inlet 102; Figure 6 and Figure 7 The specific structure of the cyclone 3 is shown in FIG. Figure 6 and Figure 7 , the rotating seat 301 is designed as an annular structure and is arranged on the inner wall of the air inlet 102. The inner wall of the rotating seat 301 is processed with an annular guide groove 302, and the cross-sectional shape of this annular guide groove 302 can be T-shaped or dovetail-shaped to ensure that the blades 304 of the subsequent fan blades 303 can slide stably therein, and can smoothly perform circular motion around the annular guide groove 302 under the action of the airflow. The fan blade 303 includes at least two blades 304. In this embodiment, two blades 304 are provided. One end of each blade 304 away from the center is slidably arranged in the annular guide groove 302 through a slider structure. Optionally, the slider structure can be a T-shaped slider or a dovetail-shaped slider. The blade 304 is made of a lightweight and heat-resistant alloy material, such as an aluminum alloy, and its shape is designed to be streamlined, similar to the cross-sectional shape of an aircraft wing. This shape can generate greater lift and torque when airflow passes through, prompting the fan blade 303 to rotate rapidly. The width of the blade 304 is determined according to the required ventilation rate of the air inlet 102. The ventilation rate requirement of the air inlet 102 is relatively high. In order to reduce the obstruction to the airflow and ensure sufficient air flow into the drying cavity 101, the area of ​​the blade 304 on the channel cross-section must meet a specific proportional relationship, that is, the area of ​​the blade 304 / the area of ​​the channel cross-section is not greater than 1 / 10.

[0054] When the hot air reaches the air inlet 102 where the cyclone 3 is installed, the airflow first hits the fan blade 303. Due to the shape of the blade 304 and the force of the airflow, the fan blade 303 begins to rotate around the annular guide groove 302. The rotating fan blade 303 further guides and accelerates the incoming hot air to form a regular spiral airflow. After the spiral airflow processed by the cyclone 3 enters the drying cavity 101, it contacts and exchanges heat with the tea leaves on the drying rack 2. During the heat exchange process, the airflow can penetrate the tea layer more evenly, thereby improving the heat exchange efficiency between the tea leaves and the hot air. At the same time, due to the enhanced stability of the spiral airflow, the airflow circulation in the drying cavity 101 is also made more orderly, reducing the energy loss caused by airflow turbulence.

[0055] In some examples, when the steam rises to the top outlet in the drying cavity 101, the flow channel shrinks to form a swirl reverse pressure, which may have an adverse effect on the drying effect of the top tea leaves, resulting in uneven drying or even damage to the top tea leaves. At this time, the driving motor 201 drives the drying rack 2 to rotate, driving the tray 202 to rotate. The rotation of the tray 202 can offset the reverse pressure generated by the steam swirl, so that the airflow can act more evenly on the tea leaves on the entire tray 202.

[0056] For example, Figure 1 , 3 As shown in FIGS. 8-10 , the drying rack 2 is rotatably arranged in the drying cavity 101 through bearings and other devices. A driving motor 201 (such as an electric motor or a combination of an electric motor and a reducer) is installed on the drying box 1, wherein its output shaft is connected to the drying rack 2 through a suitable transmission component (such as a gear set or a chain drive) to accurately control the rotation of the drying rack 2.

[0057] The rotation direction of the drying rack 2 is set to be opposite to the rotation direction of the spiral airflow. For example, if the spiral airflow rotates clockwise in the drying cavity 101, the drying rack 2 rotates counterclockwise under the drive of the driving motor 201. The reverse rotation of the drying rack 2 can effectively offset this reverse pressure. Due to the opposite rotation directions, a relative motion is formed between the tea leaves and the airflow. This relative motion causes the tea leaves on the tray 202 to continuously change the contact angle and position with the airflow, avoiding the problem of uneven heating of the local tea leaves or excessive influence of the reverse pressure due to the rotation of the airflow in a fixed direction.

[0058] In some examples, in order to make the tea leaves that are not easily contacted by airflow more easily contacted by hot air, an ultrasonic generator 4 is provided.

[0059] For example, Figure 1 , 3As shown in 8-9, the ultrasonic generator 4 is installed on the drying rack 2 through a fixing structure, such as screws and nuts, the number of which can be one or more, and the ultrasonic emission direction is toward the drying rack 2, toward the tray 202 where the tea leaves are placed.

[0060] When the system is running, the ultrasonic generator 4 emits ultrasonic waves to the tea leaves on the drying rack 2. When the ultrasonic waves act on the tea leaves, the tea leaves will vibrate slightly. For example, the ultrasonic frequency is set between 20kHz and 50kHz, and the high-frequency vibration generated by the ultrasonic waves causes the tea leaves on the tray 202 to vibrate up and down with an extremely small amplitude, which is about 0.1 mm to 1 mm.

[0061] This tiny vibration allows the inside or sunken parts of the tea leaves that are difficult for hot air to reach to be exposed to the hot air more. During the drying process, the moisture on the surface of the tea leaves evaporates first, while the moisture inside or in some hidden places is difficult to discharge. The excitation of ultrasound breaks this limitation, allowing the hot air to contact the tea leaves more comprehensively, thereby more efficiently removing the water vapor in the tea leaves.

[0062] Optionally, an isolation plate is provided above the ultrasonic generator 4. The isolation plate is made of a material that is resistant to high temperature, not easily deformed, and has little effect on ultrasonic conduction, such as a stainless steel sheet or a special engineering plastic plate. The isolation plate is firmly connected to the drying rack 2 through a fixed structure such as a bracket to ensure that it is stable and reliable during the drying process, and effectively prevents the tea leaves from falling into the ultrasonic generator 4 and the location of the drive motor 201 due to jumping, rolling, etc. during the drying process, thereby avoiding damage to these key components or affecting their normal operation.

[0063] Optionally, in order to ensure that each layer of tea leaves can better penetrate the ultrasonic wave, a slightly larger hole or annular slit that does not leak the tea leaves is opened on each layer of the tray 202 facing the ultrasonic generator 4.

[0064] In some examples, during the tea drying process, due to the different speeds and pressures at the outer edge and the center of the tray 202, an evaporation channel from the center to the outer edge is formed in each layer, and water vapor gathers outside the tray 202 and moves upward along the evaporation channel, which easily causes the condensation water to drip onto the tea tray 202 after shutdown or temperature drop. For this purpose, the adsorbent 5 is provided.

[0065] For example, Figure 1 , 3As shown in FIGS. 8-10 , the adsorbent 5 is installed on the inner wall of the drying cavity 101 and arranged at the air outlet 103. The adsorbent 5 has a through hole 501, which is connected to the air outlet 103, and the opening size of the through hole 501 gradually decreases along the first direction 104, forming an inclination angle of about 5°. A hygroscopic filler is arranged inside the adsorbent 5, and the hygroscopic filler can be selected from materials with good hygroscopic properties such as silica gel particles or activated alumina.

[0066] Since the opening size of the through hole 501 gradually decreases along the first direction 104, the humid air will gradually slow down during the passage and fully contact with the hygroscopic filler. The hygroscopic filler can absorb moisture in the air and reduce the air humidity, thereby preventing condensation from dripping onto the tea tray 202 after shutdown or temperature drop. For example, when drying a batch of tea leaves with a high moisture content, a large amount of water vapor is generated and rises during the drying process. When passing through the through hole 501 of the adsorbent 5, the silica gel particle hygroscopic filler therein can quickly capture water vapor molecules, significantly reducing the humidity of the discharged air.

[0067] At the same time, the rotation of the drying rack 2 and the circulation of the spiral airflow continuously bring out the moisture in the tea leaves and form humid air. The humid air is continuously processed by the adsorption component 5 during the movement toward the air outlet 103, thereby ensuring a dry environment in the drying cavity 101, which is beneficial to the continuous drying and quality maintenance of the tea leaves.

[0068] In some examples, the hygroscopic filler in the adsorbent 5 is saturated and cannot absorb new moisture. In this case, the water in the adsorbent 5 needs to be drained before dehumidification can be performed again. For this purpose, a first heater 6 is provided.

[0069] For example, Figure 1 , 3 As shown in FIGS. 8-10 , the first heater 6 is disposed in the drying box 1 and is located close to the adsorbent 5 , for example, it has a heating end which is attached to the adsorbent 5 , or has a heat radiation end which faces the surface of the adsorbent 5 so as to efficiently heat the adsorbent 5 .

[0070] After the adsorbent 5 has been working for a period of time, the hygroscopic filler is gradually saturated. At this time, the first heater 6 is started. The first heater 6 transfers heat to the adsorbent 5 by heat conduction or heat radiation. For example, the first heater 6 can be an electric heating wire, which generates heat when powered on, so that the temperature of the adsorbent 5 gradually increases. When the temperature of the adsorbent 5 rises to a certain level, for example, 50°C - 80°C, the moisture absorbed by the hygroscopic filler inside it begins to evaporate, forming water vapor and being discharged from the circulation system with the air flow. In this way, the adsorbent 5 is regenerated and can continue to absorb moisture to maintain the stable operation of the system.

[0071] In this embodiment, before the tea leaves are dried, the tea leaves are evenly spread on the tray 202 of the drying rack 2, and the thickness of the spread is controlled. The external hot air blower is started, and the hot air enters to form a spiral airflow, while driving the motor 201 and the ultrasonic generator 4 to work. During the drying process, the humid air moves toward the air outlet 103, and the moisture is absorbed by the adsorbent 5. When the adsorbent 5 needs to be regenerated, the first heater 6 is started to evaporate the moisture in the adsorbent 5 and discharge it.

[0072] Embodiment 3 like Figure 1 and Fig. 9 As shown, Figure 1 This is a schematic diagram of the closed state of the heat regenerator 703 of the tea drying system. Fig. 9 Schematic diagram of the tea drying system heat exchanger 703 in the open state. One end of the circulation channel 7 is connected to a plurality of air inlets 102, and the other end is connected to the air outlet 103, forming a closed air circulation loop. The first fan 701 is installed on the circulation channel 7 and is located at one end close to the air inlet 102. Its function is to blow air in the direction of the air inlet 102, provide power for the air flow to enter the drying cavity 101, and ensure that there is enough air volume to enter the drying operation area. The second fan 702 is set at one end of the circulation channel 7 close to the air outlet 103, responsible for exhausting air in the direction away from the air outlet 103, and promoting the humid air to flow smoothly in the circulation channel 7 after flowing out of the drying cavity 101. The heat exchanger 703 is arranged on the circulation channel 7, and is located between the first fan 701 and the second fan 702. The fresh air channel 704 is connected to the circulation channel 7 near the air inlet 102 through the regenerator 703, so as to introduce fresh air from the outside into the circulation system; the dehumidification channel 705 is also connected to the circulation channel 7 near the air outlet 103 through the regenerator 703, so as to discharge the air with high moisture content in the system. The second heater 706 is arranged between the first fan 701 and the air inlet 102, so as to further heat the airflow that is about to enter the drying cavity 101, so as to ensure the heat supply required for drying.

[0073] The first fan 701 and the second fan 702 are started. Under the action of the first fan 701, the outside air enters the circulation channel 7 through the fresh air channel 704, and then flows toward the air inlet 102. When passing through the second heater 706, the airflow is heated to a suitable temperature, and then enters the drying cavity 101 through the air inlet 102, forming a spiral airflow in the drying cavity 101 (assuming that the air inlet 102 has a corresponding design in the above embodiment to realize the airflow spiral), and fully exchanges heat with the tea leaves placed on the drying rack 2 (the rotating drying rack 2 and other structures can be set according to the above description), so that the moisture in the tea leaves evaporates to form humid air.

[0074] The humid air enters the circulation channel 7 from the air outlet 103 along with the air flow, and continues to flow in the circulation channel 7 under the promotion of the second fan 702. When the humid air passes through the regenerator 703, the regenerator 703 enables the air flow flowing out of one end of the air outlet 103 in the circulation channel 7 to complete heat exchange with the air flow in the fresh air channel 704. Specifically, the high-temperature humid air flowing out of the air outlet 103 transfers heat to the fresh air that is about to enter the circulation, which can not only preheat the fresh air and improve energy utilization efficiency, but also reduce the temperature of the exhaust air, which is convenient for subsequent discharge in the dehumidification channel 705. For example, the temperature of the air originally discharged from the air outlet 103 may reach 60°C, and after heat exchange, the temperature is reduced to about 40°C, which is more conducive to dehumidification operation. At the same time, the fresh air is preheated to about 30°C, reducing the energy consumption required for subsequent heating.

[0075] After the heat exchange of the humid air in the regenerator 703, part of it is discharged from the system through the dehumidification channel 705. The amount of air discharged is controlled according to the humidity in the system and the set dehumidification rules. For example, when the humidity sensor detects that the humidity in the circulation channel 7 exceeds a certain threshold, the dehumidification channel 705 is opened, or the opening of the dehumidification channel 705 is increased to discharge more humid air. The rest of the air continues to circulate in the circulation channel 7, and is heated again by the second heater 706 under the action of the first fan 701 before entering the drying cavity 101. This process repeats and forms a stable airflow cycle to continuously dry the tea leaves.

[0076] In some examples, in order to further prevent the condensation water from dripping onto the tea tray 202 due to the high moisture content of the airflow, a condensation water collecting member 8 is designed. For example, Figure 1 , 3 As shown in 10, Fig.10The figure is a detailed structural diagram of the condensate collector 8. A condensate collector 8 is provided below the air outlet 103 to collect condensate formed by condensation due to temperature changes and other reasons during the drying process, so as to prevent the condensate from dripping onto the tea leaves and affecting the quality of the tea leaves. The condensate collector 8 includes a conical cover 801, a conical ring cover 802, and a guide member 804. The top of the conical cover 801 faces the air outlet 103, and a condensate guide surface is formed at its lower end to facilitate the condensate to flow along the surface. The conical ring cover 802 is located below the conical cover 801, and the cone also faces the air outlet 103. It is provided with a water collection tank 803, and the water collection tank 803 leads to the outside of the drying cavity 101 (not shown in the figure), so that the collected condensate can be discharged from the system smoothly. The guide member 804 is an annular structure, which is bent toward the center of the circle as a whole to form an arc-shaped guide surface. The guide member 804 is arranged between the conical cover 801 and the conical ring cover 802, and a flow channel 805 is formed between it and the conical cover 801 to ensure that the humid air can pass normally. At the same time, there is a drainage hole 806 between it and the conical ring cover 802 to guide the condensed water to flow smoothly from the conical cover 801 to the water collecting tank 803 of the conical ring cover 802.

[0077] During the tea drying process, the hot air is in full contact with the tea leaves, and the moisture in the tea leaves is continuously evaporated to form water vapor, which rises with the hot air flow. When the hot air flow carries the water vapor to the vicinity of the air outlet 103, due to the relatively low external ambient temperature (for example, the external temperature of the drying box 1 is low or there is a certain heat dissipation condition at the air outlet 103), the water vapor in the hot air will condense when it is cooled to form condensed water.

[0078] At this time, the condensed water collection member 8 begins to work. First, the small water droplets formed by condensation will adhere to the conical cover 801. Under the action of gravity and the guidance of the condensed water guide surface, the water droplets will flow down along the guide surface and flow into the circulation channel 805 formed by the conical cover 801 and the guide member 804. Then, through the circulation channel 805, the water droplets will pass through the drainage hole 806 between the guide member 804 and the conical ring cover 802, and finally flow into the water collection tank 803 of the conical ring cover 802. Under the action of gravity, the condensed water in the water collection tank 803 will be discharged from the system along the channel leading to the outside of the drying cavity 101, for example, the water can be discharged into a designated collection container through a connected drainage pipe.

[0079] During the whole process, the air flow circulation in the drying cavity 101 (the hot air entering from the air inlet 102, exchanging heat with the tea leaves around the drying rack 2 and rising to the air outlet 103 with water vapor for discharge) continues normally, the tea leaves on the drying rack 2 are continuously dried, and the condensed water collecting member 8 effectively collects and discharges the condensed water that may affect the quality of the tea leaves, thereby ensuring the stability of the drying environment and the drying quality of the tea leaves.

[0080] According to the tea drying system of the present invention, another embodiment of the present invention further provides a tea drying method, which includes the following steps.

[0081] S1: Feeding The preliminarily screened and pre-treated tea leaves are evenly spread on the tray 202 of the drying rack 2 in the drying cavity 101 according to the variety and quality requirements. This ensures that the tea leaves can be evenly heated and fully dried during the drying process, while avoiding incomplete drying or quality damage due to excessive accumulation.

[0082] S2: Drying The first fan 701 connected to the air inlet 102 is started to blow the preheated air into the air inlet 102. When the airflow passes through the cyclone 3, the airflow impacts the blades 303, causing the blades 303 to rotate in the annular guide groove 302, thereby guiding and accelerating the airflow, successfully forming a spiral wind.

[0083] The spiral wind blows toward the tea leaves on the drying rack 2 along a preset spiral direction. The drying rack 2 starts to rotate under the drive of the driving motor 201, and the rotation direction is opposite to the spiral wind direction. At the same time, the ultrasonic generator 4 installed on the drying rack 2 starts to work and emits ultrasonic waves.

[0084] S3: Loop After the airflow containing a large amount of water vapor is discharged from the air outlet 103, it enters the circulation channel 7. In the circulation channel 7, it first passes through the regenerator 703. At this time, the regenerator 703 allows the high-temperature and high-humidity airflow flowing out of one end of the air outlet 103 to perform efficient heat exchange with the outside fresh air introduced from the fresh air channel 704.

[0085] A portion of the air flow after heat exchange in the regenerator 703 is discharged from the system through the dehumidification channel 705. The amount of discharged air is dynamically controlled according to the humidity conditions in the system and the set dehumidification rules. The remaining air continues to circulate in the circulation channel 7 under the action of the first fan 701, and is heated to a suitable drying temperature again when passing through the second heater 706. Then, it re-enters the drying cavity 101 through the air inlet 102 to start a new round of drying cycle.

[0086] S4: Condensate collection and treatment During the drying process, when the hot air flow carries water vapor and rises to the vicinity of the air outlet 103, the water vapor condenses to form condensed water. The condensed water droplets will adhere to the conical cover 801. Under the action of gravity and the guidance of the condensed water guide surface, the water droplets flow downward along the guide surface and flow into the flow channel 805 formed by the conical cover 801 and the guide member 804. The water droplets pass through the flow channel 805, and then the water droplets pass through the drainage hole 806 between the guide member 804 and the conical ring cover 802, and finally flow into the water collection tank 803 of the conical ring cover 802.

[0087] S5: Dehumidification and regeneration As the drying process continues, the humidity in the drying cavity 101 gradually increases. Due to the different speeds and pressures at the outer edge and the center of the tray 202, an evaporation channel from the center to the outer edge is formed in each layer, and water vapor gathers outside the tray 202 and moves upward. When the humid air reaches the top, it enters the through hole 501 of the adsorbent 5. Since the opening size of the through hole 501 gradually decreases along the first direction 104, the humid air will gradually slow down during the passage and fully contact with the hygroscopic filler. After the adsorbent 5 has been working for a period of time, the hygroscopic filler is gradually saturated. At this time, the first heater 6 is started, and the first heater 6 transfers heat to the adsorbent 5 by heat conduction or heat radiation. When the temperature of the adsorbent 5 rises, the moisture absorbed by the hygroscopic filler inside it begins to evaporate, forming water vapor and being discharged from the circulation system with the airflow.

[0088] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure rather than to limit it. Although the present disclosure has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present disclosure may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present disclosure, which should be included in the scope of the claims of the present disclosure.

Claims

1. Tea drying system, including: A drying box (1), wherein a drying cavity (101) is provided inside the drying cavity (101); an air inlet (102) is provided at one end of the drying cavity (101), and an air outlet (103) is provided at the other end; A drying rack (2), which is arranged in the drying cavity (101) and located between the air inlet (102) and the air outlet (103); It is characterized in that there are a plurality of air inlets (102) which are arranged at intervals along the circumference of the drying cavity (101), and the direction from one end where the air inlet (102) is located to the end where the air outlet (103) is located is a first direction (104), and the opening direction of at least one of the air inlets (102) is inclined relative to the radial direction of the drying cavity (101) and the first direction (104), so that the airflow entering the drying cavity (101) forms a spiral airflow.

2. The tea drying system according to claim 1, characterized in that: The drying cavity (101) is a columnar channel, and a plurality of the air inlets (102) are arranged in pairs, and each pair of the air inlets (102) are arranged opposite to each other and have opposite opening directions.

3. The tea drying system according to claim 1, characterized in that: The drying cavity (101) is a columnar channel, and the angle between the opening direction of the inclined air inlet (102) and the radial direction of the drying cavity (101) is α, and α is an acute angle; The angle between the opening direction of the inclined air inlet (102) and the first direction (104) is β, and the angle β is 65° to 75°.

4. The tea drying system according to claim 1, characterized in that: A plurality of pairs of the air inlets (102) are arranged at intervals along the circumferential direction on the side wall of the drying cavity (101) or the bottom of the drying cavity (101).

5. The tea drying system according to claim 1, characterized in that: Also includes: A cyclone (3), arranged at at least one of the air inlets (102), comprising: A rotating seat (301) which is annular and is arranged on the inner wall of the air inlet (102), and the inner wall of the rotating seat has an annular guide groove (302); The fan blade (303) has at least two blades (304), and one end of the blade (304) away from the center is slidably disposed in the annular guide groove (302).

6. The tea drying system according to claim 1, characterized in that: The drying rack (2) is rotatably disposed in the drying cavity (101); and further comprises: A driving motor (201) is arranged on the drying box (1) and drives the drying rack (2) to rotate, wherein the rotation direction of the drying rack (2) is opposite to the rotation direction of the spiral airflow.

7. The tea drying system according to claim 1, characterized in that: Also includes: An ultrasonic generator (4) is used to emit ultrasonic waves to the tea leaves on the drying rack (2).

8. The tea drying system according to claim 1, characterized in that: Also includes: an adsorption member (5), which is arranged on the inner wall of the drying cavity (101) and disposed at the air outlet (103), and has a through hole (501), wherein the through hole (501) is connected to the air outlet (103); the opening size of the through hole (501) gradually decreases along the first direction (104); A first heater (6) is arranged in the drying box (1) and is used to heat the adsorption element (5).

9. The tea drying system according to claim 1, characterized in that: Also includes: A circulation channel (7), one end of which is connected to the plurality of air inlets (102), and the other end of which is connected to the air outlet (103); a regenerator (703), which is arranged on the circulation channel (7); A fresh air channel (704) connected to the circulation channel (7) at one end close to the air inlet (102) through the regenerator (703); a moisture removal channel (705) which is connected to the circulation channel (7) at one end close to the air outlet (103) through the heat regenerator (703); The regenerator (703) enables the airflow flowing out of one end of the air outlet (103) in the circulation channel (7) to complete heat exchange with the airflow in the fresh air channel (704); A second heater (706) is arranged in front of the air inlet (102).

10. A method for drying tea leaves, using the tea leaves drying system according to any one of claims 1 to 9, characterized in that: The drying method comprises the following steps: S1: feeding tea leaves, placing the tea leaves on a drying rack (2) in a drying cavity (101); S2: Drying, blowing air into the drying cavity (101) through the air inlet (102) to form a spiral wind; the spiral wind blows toward the tea leaves to complete the drying.

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