A coil furnace for steam drying

Abstract

The utility model relates to a kind of coil furnace for steam drying, including main body and the coil assembly of being set in the vertical lower bottom of main body. Coil assembly's steam inlet is connected with high-temperature high-pressure steam device. Coil assembly's steam outlet is connected with the vertical bottom of main body. Coil assembly is set as helically extending pipeline, and steam inlet is located at the periphery of helical pipeline. Steam outlet is located at the axis of helical pipeline to form the steam flow pipeline from outside to inside. The helical pipeline of coil assembly is set as variable cross-section structure. The coil furnace of the utility model is heated to the tea inside main body by the flow process of steam in coil assembly while killing green by steam to the tea inside main body, so as to remove water vapor in tea by the way of improving temperature.

Description

Technical Field

[0001] This utility model relates to the field of tea processing technology, and in particular to a coil furnace for steam drying. Background Technology

[0002] In the initial processing of green tea, fixation is a crucial step that determines the quality of the finished tea. The key lies in rapidly deactivating polyphenol oxidases in the fresh leaves at high temperatures, preventing enzymatic oxidation and preserving the tea's vibrant green color and natural flavor compounds. Currently, the industry commonly uses steam fixation, which involves heating the leaves below a permeable conveyor belt to generate steam below 105°C. This steam penetrates the fresh leaves, inhibiting enzyme activity. However, this traditional process has significant technical limitations.

[0003] Traditional steam-fired green tea equipment uses an open structure, where steam heat is not effectively recovered and utilized. After firing, a large amount of residual heat from the equipment and pipes is directly emitted with the exhaust gas. The subsequent drying process requires reheating the air to 120-150℃ to remove the moisture added during firing, resulting in a 30%-40% increase in energy consumption per unit compared to the theoretical value. According to industry statistics, a processing plant producing 500 tons of green tea annually experiences an additional 150,000 kilowatt-hours of electricity consumption annually just in the drying process, significantly increasing processing costs.

[0004] Steam-fired leaf-blanking equipment typically employs a single-layer, flat-lay structure for supporting fresh leaves. Steam penetrates unidirectionally from the bottom, resulting in uneven heating between the upper and lower layers. Furthermore, the high steam flow resistance and low heat exchange efficiency lead to significant temperature fluctuations on the pipe surface, easily causing localized oversaturation or underheating. In addition, the equipment lacks a mechanism for storing residual heat after blanching, requiring complete reliance on external heat sources for reheating during the drying stage, further exacerbating energy waste and inconsistent quality.

[0005] To address the aforementioned industry pain points, it is necessary to develop a new type of equipment that can reduce the absorption of moisture in fresh leaves during the fixation process, efficiently utilize the waste heat of steam, and integrate the fixation-drying process. This would solve the technical problems of quality deterioration and high energy consumption in traditional processes, and promote the energy-saving and intelligent upgrading of green tea primary processing equipment.

[0006] Furthermore, on the one hand, there are differences in understanding among those skilled in the art; on the other hand, the applicant studied a large number of documents and patents when making this utility model, but due to space limitations, not all details and contents were listed in detail. However, this does not mean that this utility model does not have the features of these prior art. On the contrary, this utility model has all the features of the prior art, and the applicant reserves the right to add relevant prior art to the background art. Utility Model Content

[0007] To address the shortcomings of existing technologies, this utility model provides a coil furnace for steam drying, comprising a main body and a coil assembly disposed on the vertical bottom surface of the main body. The steam inlet of the coil assembly is connected to a high-temperature, high-pressure steam device. The steam outlet of the coil assembly is connected to the axis of the vertical bottom surface of the main body. The coil assembly is configured as a spirally extending pipe, with the steam inlet located at the periphery of the spiral pipe. The steam outlet is located at the axis of the spiral pipe to form a steam flow pipe from the outside to the inside. The spiral pipe of the coil assembly has a variable cross-section structure.

[0008] According to a preferred embodiment, the diameter of the coil assembly gradually decreases from the steam inlet to the steam outlet, and a spiral guide groove is provided on the inner wall of the pipe, the depth of which gradually becomes shallower along the steam flow direction.

[0009] According to a preferred embodiment, the spiral conduit of the coil assembly is composed of inner and outer double-walled sections, forming a sandwich structure. The sandwich structure is filled with energy storage material and contains an axially extending capillary network.

[0010] According to a preferred embodiment, the steam outlet is connected to a spray chamber located on the bottom surface inside the main body. The spray chamber has several spray heads arranged in a ring at its vertical upper end.

[0011] According to a preferred embodiment, a layered frame is provided inside the main body. The frame is located vertically above the spray head and divides the interior of the main body into several layers in the vertical direction.

[0012] According to a preferred embodiment, slide rails are provided on corresponding frames of several layers. The frames are also provided with holders for carrying tea leaves. The sides of the holders are fitted into the slide rails in a manner that allows the holders to slide horizontally out of the frame layers.

[0013] According to a preferred embodiment, the vertical bottom surface of the placement component is provided with an array of vent holes for steam to pass through.

[0014] According to a preferred embodiment, a switch door is provided on the side wall of the main body. The switch door is arranged such that it covers the side of the main body in the sliding direction of a plurality of placement components.

[0015] According to a preferred embodiment, a polymer shroud is provided at the vertical top of the main body. The polymer shroud includes inclined guide vanes and an exhaust component located at the center of the vertical top of the main body. The inclination angle of the guide vanes gradually increases radially along the exhaust component.

[0016] According to a preferred embodiment, a plurality of support columns are provided on the vertical bottom surface of the main body. A heating device is externally connected to the coil assembly within the space formed by the plurality of support columns. Attached Figure Description

[0017] Figure 1 This is a simplified structural diagram of a coil furnace for steam drying according to a preferred embodiment of the present invention.

[0018] Figure 2 This is a simplified structural diagram of the coil furnace after the main body has been cut out, according to a preferred embodiment of the present invention.

[0019] Figure 3 This is a simplified structural diagram of a coil furnace after removing the placement component, according to a preferred embodiment of this utility model.

[0020] Figure 4 This is a simplified structural diagram of a coil assembly according to a preferred embodiment of the present invention;

[0021] Figure 5 This is a simplified structural diagram of a guide plate according to a preferred embodiment of the present invention.

[0022] List of reference numerals

[0023] 100: Main body; 101: Spray chamber; 102: Spray head; 103: Frame; 104: Slide rail; 105: Placement component; 106: Vent hole; 107: Opening and closing door; 108: Aggregator cover; 109: Guide vane; 110: Exhaust component; 200: Coil assembly; 201: Steam inlet; 202: Steam outlet. Detailed Implementation

[0024] The following is a detailed explanation with reference to the accompanying drawings.

[0025] Example 1

[0026] This utility model provides a coil furnace for steam drying, such as Figure 1As shown, the device includes a main body 100 and a coil assembly 200 disposed on the vertically downward bottom surface of the main body 100. The steam inlet 201 of the coil assembly 200 is connected to a high-temperature, high-pressure steam device. The steam outlet 202 of the coil assembly 200 is connected to the axis of the vertically downward bottom surface of the main body 100. The coil assembly 200 is configured as a spirally extending pipe, with the steam inlet 201 located on the periphery of the spiral pipe. The steam outlet 202 is located at the axis of the spiral pipe to form a steam flow pipe from the outside to the inside. The spiral pipe of the coil assembly 200 is configured as a variable cross-section structure. This invention's coil furnace uses steam to kill the tea leaves inside the main body 100, while simultaneously heating the interior of the main body 100 by the flow of steam within the coil assembly 200, thereby removing moisture from the tea leaves by increasing the temperature. Furthermore, in this invention's device, the coil assembly 200 can be circulated with both steam and air. When tea leaves need processing, steam can be introduced first to kill the greening effect. Since the coil assembly 200 heats the main body 100 after steam is introduced, the increase in moisture content of the tea leaves is negligible. The pre-introduction of steam has already preheated the interior of the main body 100, and the coil assembly 200 already stores a certain amount of heat. Based on this, the operator can introduce preheated air through the coil assembly 200 to quickly dry the tea leaves in the main body 100. This method effectively utilizes the heat of steam, saves on tea processing steps, eliminates the need to consume large amounts of energy to remove moisture from the tea leaves, reduces processing costs, and ensures tea quality.

[0027] This invention utilizes a spiral coil assembly 200 to achieve a circular flow path of steam from the outside to the inside, expanding the heat exchange area between the steam and the inner wall of the main body 100, thus making the internal temperature field distribution of the main body 100 more uniform. The variable cross-section pipe design of the coil assembly 200 optimizes the steam flow resistance, and with the dual-mode switching of steam fixation and air drying, it achieves rapid heating in the fixation stage and utilization of waste heat in the drying stage, saving more than 30% energy compared to traditional equipment. At the same time, it avoids the oxidation of tea leaves caused by repeated heating, thus maintaining the content of effective components such as tea polyphenols.

[0028] According to a preferred embodiment, such as Figure 4As shown, the diameter of the coil assembly 200 gradually decreases from the steam inlet 201 to the steam outlet 202, and a spiral guide groove is provided on the inner wall of the pipe, the depth of which gradually decreases along the steam flow direction. Preferably, the inner wall of the pipe is electrolytically polished to reduce steam condensate residue. Preferably, the spiral pipe of the coil assembly 200 adopts a gradually changing cross-section structure. Preferably, the diameter of the coil assembly 200 decreases with each turn of the spiral path. More preferably, the diameter of the steam inlet 201 is twice the diameter of the steam outlet 202. In this invention, the initial diameter of the steam inlet 201 is 80mm, decreasing by 5mm with each turn of the spiral path, shrinking to 40mm at the steam outlet 202, and the pipe wall thickness linearly decreases from 3mm to 2mm, ensuring a stable steam pressure gradient while reducing the pipe's own heat loss. The tapered pipe design of this invention forms a steam acceleration channel, which increases the steam velocity and enhances the turbulence effect; the spiral guide groove decreases from the inlet to achieve dynamic and uniform heat exchange between the steam and the inner wall of the pipe, and the temperature deviation of the pipe surface is controlled within ±5℃ to avoid local overheating and scorching of tea leaves.

[0029] According to a preferred embodiment, the spiral pipe of the coil assembly 200 is composed of inner and outer double-walled sections, forming a sandwich structure. The sandwich structure is filled with energy storage material and contains an axially extending capillary network. The energy storage material within the sandwich can store waste heat from steam and release latent heat during the air drying stage, thereby reducing temperature fluctuations in the main body 100. The axial capillary network evenly distributes the stored heat, improving the uniformity of heat release.

[0030] According to a preferred embodiment, the steam outlet 202 is connected to a spray chamber 101 located on the bottom surface inside the main body 100. A plurality of annularly arranged spray heads 102 are provided at the vertical end of the spray chamber 101. The annularly arranged spray heads 102 ensure that steam is evenly sprayed onto the surface of the tea leaves, effectively improving the withering efficiency. The spray chamber 101 transforms the concentrated steam flow from the steam outlet 202 into annular thin-layer airflow, avoiding excessive agitation of the tea leaves due to localized steam impact, and simultaneously preventing an increase in the moisture content of the tea leaves.

[0031] According to a preferred embodiment, such as Figure 3 As shown, the main body 100 has a frame 103 for layering inside. The frame 103 is located vertically above the spray head 102 and divides the interior of the main body 100 into several layers in the vertical direction. The frame 103 divides the interior of the main body into several layers, realizing the layered spreading of tea leaves and facilitating the batch processing of different types of tea leaves.

[0032] According to a preferred embodiment, slide rails 104 are provided on corresponding frames 103 of several layers. A holder 105 for holding tea leaves is also provided on the frame 103. The side of the holder 105 engages with the slide rails 104 in a manner that allows the holder 105 to slide horizontally out of the layers of the frame 103. The drawer-type holder 105, in conjunction with the slide rails 104, allows for gap sliding, enabling one-handed operation and improving retrieval efficiency. An L-shaped handle is provided on the edge of the holder 105 to ensure that the operator can quickly pull out the holder 105. Preferably, rollers can also be provided at the contact points between the frame 103 and the holder 105 to reduce friction between them. For example, at the contact point between the frame 103 and the vertical base plate of the holder 105, rollers can be embedded in the frame 103, allowing the base plate of the holder 105 to be pulled out on the rollers.

[0033] According to a preferred embodiment, such as Figure 2 As shown, the vertical bottom surface of the placement component 105 is provided with an array of ventilation holes 106 for steam to pass through. The array of ventilation holes 106 enables three-dimensional penetration and drying of steam, maximizing airflow rate while ensuring load-bearing strength.

[0034] According to a preferred embodiment, a switch door 107 is provided on the side wall of the main body 100. The switch door 107 is arranged to cover the side of the main body in the sliding direction of a plurality of placement members 105. The cover-type switch door 107 ensures the airtightness of the main body 100. Preferably, an observation window can be provided on the switch door 107 to facilitate real-time observation of the tea leaves' condition.

[0035] According to a preferred embodiment, a polymer shroud 108 is provided at the vertical top of the main body 100. The polymer shroud 108 includes inclined guide vanes 109 and an exhaust component 110 located at the center of the vertical top of the main body 100. Figure 5 As shown, the tilt angle of the guide vane 109 gradually increases radially along the exhaust component 110. Preferably, the exhaust component 110 can be connected to an external fan to increase the steam outflow rate. The tilt angle of the guide vane 109 gradually changes from 15° at the edge to 45° at the center, causing the rising airflow to form a spiral clustering effect, discharging steam from the exhaust component 110 and preventing condensate dripping from the top and contaminating the tea leaves. The inner wall of the polymer cover 108 is coated with a nano-hydrophobic coating to reduce steam condensation and adhesion to the wall.

[0036] According to a preferred embodiment, a plurality of support columns are provided on the vertical bottom surface of the main body 100. A heating device is externally connected to the coil assembly 200 within the space formed by the support columns. The bottom space formed by the support columns facilitates the inspection and maintenance of the heating device.

[0037] It should be noted that the specific embodiments described above are exemplary. Those skilled in the art can devise various solutions inspired by the disclosure of this utility model, and these solutions all fall within the scope of this utility model and its protection scope. Those skilled in the art should understand that this utility model specification and its drawings are illustrative and do not constitute a limitation on the claims. The protection scope of this utility model is defined by the claims and their equivalents. This utility model specification contains multiple inventive concepts; phrases such as "preferred" or "according to a preferred embodiment" indicate that the corresponding paragraph discloses an independent concept. The applicant reserves the right to file divisional applications based on each inventive concept. Throughout the text, the feature introduced by "preferred" is only an optional mode and should not be construed as mandatory. Therefore, the applicant reserves the right to abandon or delete relevant preferred features at any time.

Claims

1. A coil furnace for steam drying, characterized in that, The system includes a main body (100) and a coil assembly (200) disposed on the vertical bottom surface of the main body (100). The steam inlet (201) of the coil assembly (200) is connected to a high-temperature and high-pressure steam device, and the steam outlet (202) of the coil assembly (200) is connected to the axis of the vertical bottom surface of the main body (100). The coil assembly (200) is configured as a spirally extending pipe, and the steam inlet (201) is located on the periphery of the spiral pipe, and the steam outlet (202) is located at the axis of the spiral pipe to form a steam flow pipe from the outside to the inside, wherein the spiral pipe of the coil assembly (200) is configured as a variable cross-section structure.

2. The coil furnace for steam drying according to claim 1, characterized by The diameter of the coil assembly (200) gradually decreases from the steam inlet (201) to the steam outlet (202), and the inner wall of the pipe is provided with a spiral guide groove, the depth of which gradually becomes shallower along the steam flow direction.

3. The coil furnace for steam drying according to claim 2, characterized by The spiral pipe of the coil assembly (200) is composed of inner and outer double-layer pipe walls to form a sandwich structure. The sandwich structure is filled with energy storage material and is provided with an axially extending capillary network.

4. The coil furnace for steam drying according to claim 3, characterized by The steam outlet (202) is connected to the spray chamber (101) located on the bottom surface inside the main body (100), and the spray chamber (101) is provided with a plurality of spray heads (102) arranged in a ring at its vertical end.

5. The coil stove for steam drying according to claim 4, characterized in that The main body (100) is provided with a layered frame (103) inside, which is located vertically above the spray head (102) and divides the interior of the main body (100) into several layers in the vertical direction.

6. The coil stove for steam drying according to claim 5, characterized in that Several of the aforementioned levels of the frame (103) are provided with slide rails (104), and the frame (103) is also provided with a holder (105) for carrying tea leaves. The side of the placement member (105) is fitted with the slide rail (104) in such a way that the placement member (105) slides horizontally out of the layers of the frame (103).

7. The coil stove for steam drying according to claim 6, characterized in that The vertical bottom surface of the placement member (105) is provided with an array of several vent holes (106) for steam to pass through.

8. The coil stove for steam drying according to claim 7, characterized in that A switch door (107) is provided on the side wall of the main body (100), and the switch door (107) is arranged in such a way that it covers the side of the main body in the sliding direction of the plurality of placement members (105).

9. The coil stove for steam drying according to claim 8, characterized in that The main body (100) is provided with a polymer cover (108) at its vertical top. The polymer cover (108) includes an inclined guide plate (109) and an exhaust component (110) located at the center of the vertical top of the main body (100). The inclination angle of the guide plate (109) gradually increases radially along the exhaust component (110).

10. The coil stove for steam drying according to claim 9, characterized in that The main body (100) has several support columns on its vertical bottom surface, and a heating device is connected to the coil assembly (200) in the space formed by the several support columns.

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