A high-efficiency and energy-saving forward and reverse rotating fan for intensive tobacco curing barns

Abstract

This utility model provides a high-efficiency and energy-saving forward and reverse rotating fan for intensive tobacco curing barns, belonging to the field of tobacco curing technology. The high-efficiency and energy-saving forward and reverse rotating fan for intensive tobacco curing barns includes a curing barn, a forced exhaust fan fixed to the wall of the curing barn, and a cold air inlet below the forced exhaust fan. The cold air inlet is used to expel moisture from the curing barn. A forward and reverse rotation controller is fixed on the forced exhaust fan, and the forced exhaust fan is electrically connected to the controller. The forced exhaust fan is used to generate two unidirectional airflows to promote airflow circulation. The invention is characterized by two detachable air-blocking structures connected to the upper and lower sections of the curing barn. The two air-blocking structures are symmetrically arranged vertically and vertically, and are used to change the direction of airflow. A guide structure is provided on the inner wall of the forced exhaust fan to form a gas flow channel. This utility model can solve the problem of uneven heating of tobacco leaves during the curing process in traditional curing barns.

Description

Technical Field

[0001] This utility model belongs to the field of tobacco curing technology, specifically, it relates to a high-efficiency and energy-saving forward and reverse rotating fan for intensive tobacco curing barns. Background Technology

[0002] Curing barns are indispensable facilities in the tobacco processing industry. Their main function is to dry and ferment tobacco leaves under specific conditions by controlling temperature and humidity. One of the core pieces of equipment in a curing barn is the fan, which plays a crucial role in regulating airflow. The fan's function is to provide forced ventilation and heat exchange, three-dimensional circulating hot air and dynamic dehumidification, and to enhance the utilization of hot air circulation, thereby improving curing efficiency and product quality.

[0003] Existing conventional dense tobacco curing barns have a single direction of hot air circulation, resulting in a significant temperature difference between the top and bottom loading areas. There are also rising and falling types of curing barns. During actual curing, the large vertical and horizontal temperature differences within the barn (4-5℃ vertical and 2-3℃ horizontal) lead to uneven heating of the upper and lower layers of tobacco leaves, resulting in significant differences in yellowing rates. This, in turn, causes a series of prominent problems, including difficulties in implementing the curing process, increased ineffective curing time, uneven curing quality, inconsistent tobacco leaf quality, and high energy consumption costs.

[0004] Uneven curing of tobacco can lead to some leaves being over-cured, becoming too dry and losing their proper aroma and flavor; while other leaves may not be completely dried, resulting in insufficient fermentation and affecting their flavor and texture. This uneven curing process not only affects the overall quality of the product but also leads to resource waste and increased production costs. Utility Model Content

[0005] In view of this, the present invention provides a high-efficiency and energy-saving forward and reverse rotating fan for intensive tobacco curing barns, which can solve the problem of uneven heating of tobacco in traditional curing barns.

[0006] This utility model is implemented as follows:

[0007] This utility model provides a high-efficiency and energy-saving forward and reverse rotating fan for intensive tobacco curing barns, including a curing barn, a forced exhaust fan fixed to the wall of the curing barn, and a cold air inlet below the forced exhaust fan. The cold air inlet is used to exhaust moisture in the curing barn. A forward and reverse rotation controller is fixed on the forced exhaust fan, and the forced exhaust fan is electrically connected to the forward and reverse rotation controller. The forced exhaust fan is used to generate two unidirectional airflows to promote airflow circulation. Among them, two air-blocking structures are detachably connected in the upper and lower parts of the curing barn. The two air-blocking structures are symmetrically arranged vertically and vertically. The air-blocking structures are used to change the flow direction of airflow. A flow guide structure is provided on the inner wall of the forced exhaust fan to form a gas flow channel.

[0008] Based on the above technical solution, the high-efficiency and energy-saving forward and reverse rotating fan for intensive tobacco curing barns of this utility model can be further improved as follows:

[0009] The wind-blocking structure includes a support rod, a guide plate, a first fixing block, and a second fixing block. The support rod is a cubic strip structure. The first fixing block is fixedly connected to the left side wall of the support rod, and the second fixing block is fixed to the right side wall of the support rod. The top of the support rod is connected to the guide plate through a hinge. The guide plate is a lightweight plate structure, and a torsion spring is installed inside the hinge.

[0010] The beneficial effects of adopting the above-mentioned improved scheme are as follows: The rational arrangement of components such as the fixing blocks, guide plates, and support rods in the wind structure allows for more efficient guidance and control of airflow, thereby improving the working efficiency of the fan and reducing energy consumption. It can guide airflow throughout the drying chamber, reducing dead air zones. The combination of hinge connections and torsion springs allows the guide plates to automatically adjust their angle according to the airflow volume, ensuring optimal airflow guidance under different airflow conditions. Frequent manual adjustment of the guide plate angle is eliminated, reducing operational complexity and saving labor costs.

[0011] Furthermore, the first fixing block is an isosceles right triangle structure, with the right-angled side of the first fixing block being fixedly connected to the side wall of the support rod, and the support rod and the first fixing block forming a flag-shaped structure.

[0012] The beneficial effects of adopting the above-mentioned improved scheme are as follows: the tilt range of the guide plate can be limited by the first and second fixing blocks. Limiting the tilt angle ensures that the guide plate always works within the design range, maintaining a stable airflow pattern in the curing barn and avoiding adverse effects on the quality of the tobacco caused by drastic changes in the airflow pattern.

[0013] Furthermore, the second fixing block includes a first connecting part and a second connecting part. The first connecting part has a right-angled trapezoidal structure, and the second connecting part has a rectangular structure. The top surface of the right-angled trapezoid is fixedly connected to the side wall of the support rod, and the bottom edge of the right-angled trapezoid is fixedly connected to the long side of the rectangle.

[0014] Furthermore, the length of the lower base of the right-angled trapezoid of the first connecting part is the same as the length of the long side of the rectangle of the second connecting part, and the surface of the short side of the second connecting part is flush with the top surface of the support rod.

[0015] Furthermore, the isosceles right triangle structure of the first fixing block has multiple heat dissipation holes on its hypotenuse. These holes are used to increase the heat dissipation effect of the airflow and improve the temperature uniformity inside the baking oven.

[0016] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: the heat dissipation hole design promotes more even airflow distribution within the curing barn, reducing localized heat concentration or insufficient heat. Uniform temperature helps ensure consistent coloring of the tobacco leaves during curing, preventing some leaves from being too dark or too light, thus improving the appearance quality and market value of the tobacco leaves. A uniform temperature environment ensures consistent moisture evaporation rates across all parts of the tobacco leaves, preventing some leaves from becoming too dry and brittle while others become too wet and prone to mold, thereby improving the storage stability of the tobacco leaves.

[0017] Furthermore, the rectangular structure of the second connecting part of the second fixing block is provided with multiple grooves. The grooves are used to increase the disturbance of the airflow and improve the mixing effect of the airflow, thereby improving the uniformity of the flue-cured tobacco.

[0018] The beneficial effects of adopting the above-mentioned improvement scheme are: effective airflow mixing can deliver hot air to every corner of the curing room, avoid airflow stagnation areas, thereby eliminating curing dead corners and ensuring that all tobacco leaves are fully cured.

[0019] Furthermore, the surface of the deflector is coated with an anti-corrosion coating to prevent corrosion of the deflector in high temperature and high humidity environments.

[0020] The flow guiding structure includes multiple arc-shaped flow guiding vanes, which are evenly distributed along the circumference of the inner wall of the forced exhaust fan. Each flow guiding vane can rotate around its radial axis, and the angle of the flow guiding vane ranges from 0 to 45°. The surface of the flow guiding vane is smooth, and the cross-section has a streamlined structure. The back of the flow guiding vane is fixedly connected to one end of a connecting rod. The connecting rod passes through the side wall of the forced exhaust fan and is rotatably connected to the side wall of the forced exhaust fan. An adjustment terminal is fixedly connected to the other end of the connecting rod, and a scale is set on the outer wall of the forced exhaust fan corresponding to the adjustment terminal.

[0021] Furthermore, the upper surface of the deflector is provided with curved grooves, and the curvature of the grooves near the support rod is less than that of the original support rod. The curved groove structure can more effectively reflect the airflow in multiple directions, realize the step-by-step guidance and diffusion of the airflow, and reduce the turbulence of the airflow.

[0022] The airflow guiding structure design effectively directs airflow, reduces turbulence and resistance, and improves the efficiency and performance of the fan. The guide vanes can rotate around their radial axis within a range of 0-45°, allowing for adjustment to optimize airflow direction and fan performance. The guide vanes are rotatably connected to the fan sidewall via connecting rods, resulting in a simple structure that is easy to install and maintain, while also improving fan reliability. The airflow direction can be adjusted as needed to further enhance the chimney effect.

[0023] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: the curved groove design allows the airflow to be gradually guided and diffused as it passes through the guide plate, rather than suddenly changing direction. This step-by-step guidance reduces airflow turbulence, making the airflow more evenly distributed in the baking oven. Through step-by-step guidance and diffusion, the airflow can be more evenly distributed in all areas of the baking oven, avoiding situations where the local airflow is too strong or too weak, and improving the uniformity of baking.

[0024] Furthermore, the upper surface of the deflector is provided with multiple tiny protrusions arranged irregularly to increase the surface roughness of the deflector, change the flow state of the airflow on the surface of the deflector, and enhance the mixing and guiding effect of the airflow.

[0025] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: the tiny protrusions can effectively disrupt the airflow boundary layer on the surface of the guide plate. The originally smooth airflow will generate tiny eddies and turbulence due to the protrusions, enhancing the airflow mixing effect and making the temperature and humidity distribution in the curing barn more uniform. The protrusions can break the original laminar flow state, increase the degree of airflow turbulence, and allow the airflows of different temperatures and humidity that were originally layered to mix better, reducing thermal stratification and ensuring that all parts of the tobacco leaf are heated evenly.

[0026] Compared with existing technologies, the advantages of this utility model for a high-efficiency, energy-saving forward and reverse rotating fan for intensive tobacco curing barns are:

[0027] 1. Under the control of the forward and reverse rotation controller, the forced exhaust fan adopts a forward and reverse air supply mode. When rotating forward, the airflow descends and is supplied; when rotating in reverse, the airflow rises and is supplied. This continuous switching forms a three-dimensional airflow circulation, breaking the limitation of the traditional single-direction air supply for flue-cured tobacco. It significantly improves the airflow circulation efficiency in the curing barn, making the tobacco leaves heat more evenly and lose moisture more quickly. At the same time, it can save 15-20 hours of curing time and save more than 100KG of fuel (biomass pellets), greatly reducing the cost of curing tobacco.

[0028] 2. The circulating airflow ensures that all parts of the tobacco leaves are heated evenly, avoiding local overheating or under-roasting, thereby significantly improving the overall roasting quality of the tobacco leaves and enhancing their color, aroma, and taste.

[0029] 3. The airflow circulation formed by the forward and reverse air supply can effectively remove moisture from the surface of the tobacco leaves, while promoting the diffusion of moisture from inside the tobacco leaves to the outside, preventing moisture from accumulating inside the tobacco leaves, thereby improving the uniformity of the baking process.

[0030] 4. The vertical airflow breaks up the temperature gradient in the curing barn, reduces the generation of high-temperature and low-temperature zones, and makes the temperature in the entire curing barn more uniform, which is conducive to improving the consistency of tobacco curing.

[0031] 5. The ventilation structure guides the airflow exhausted by the powerful exhaust fan to other parts of the curing barn, ensuring uniform airflow distribution and preventing localized areas of excessively strong or weak airflow, thereby improving the uniformity of tobacco curing. It also guides airflow to every corner of the barn, reducing dead zones and ensuring that each tobacco leaf is heated evenly, thus improving the overall quality of the cured tobacco. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A schematic diagram of a high-efficiency and energy-saving forward and reverse rotating fan for intensive tobacco curing barns;

[0034] Figure 2 This is a baking process curve diagram for Example 1;

[0035] Figure 3 This is a schematic diagram showing the temperature changes during different stages of tobacco leaf curing in Example 1.

[0036] Figure 4 This is a graph showing the dry and wet temperature curves during the baking process in oven No. 1 of Example 2.

[0037] Figure 5 This is a comparison diagram of the baking processes in baking chamber No. 1 and baking chamber No. 9 in Example 2;

[0038] Figure 6 This is a graph showing the dry and wet temperature curves during the baking process in oven No. 2 of Example 2.

[0039] Figure 7 This is a comparison diagram of the baking processes in baking chambers No. 2 and No. 9 in Example 2;

[0040] Figure 8 This is a graph showing the dry and wet temperature curves during the baking process in oven No. 5 of Example 2.

[0041] Figure 9 This is a comparison diagram of the baking processes in baking chambers No. 5 and No. 9 in Example 2;

[0042] Figure 10 This is a graph showing the dry and wet temperature curves during the baking process in oven No. 15 of Example 2.

[0043] Figure 11 This is a comparison diagram of the baking processes in baking room No. 15 and baking room No. 9 in Example 2;

[0044] Figure 12 This is a graph showing the dry and wet temperature curves during the baking process in oven No. 9 of Example 2.

[0045] Figure 13 A schematic diagram of the upward airflow delivery method of a forced exhaust fan;

[0046] Figure 14 A schematic diagram of a forced exhaust fan's downward airflow delivery method;

[0047] Figure 15 A front view of a high-efficiency, energy-saving, reversible forced exhaust fan for a dense tobacco curing barn;

[0048] Figure 16 A schematic diagram of the inner wall structure of a high-efficiency, energy-saving forward and reverse rotating fan for a dense tobacco curing barn;

[0049] The attached diagram lists the components represented by each number as follows:

[0050] 10. Forced exhaust fan; 20. Cold air inlet damper; 30. Forward and reverse rotation controller; 40. Airflow structure; 41. Support rod; 42. Guide plate; 43. First fixing block; 44. Second fixing block; 50. Airflow guide structure; 60. Connecting rod. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0052] like Figure 1 Figures 15 and 16 show schematic diagrams of a high-efficiency energy-saving forward and reverse rotating fan for a dense tobacco curing barn provided by this utility model. In this embodiment, the barn includes a curing barn, a forced exhaust fan 10 fixed on the wall of the barn, and a cold air inlet 20 below the forced exhaust fan 10. The cold air inlet 20 is used to exhaust moisture in the barn. A forward and reverse rotating controller 30 is fixed on the forced exhaust fan 10 and is electrically connected to the forward and reverse rotating controller 30. The forced exhaust fan 10 is used to generate two unidirectional airflows to promote airflow circulation. Two air-blocking structures 40 are detachably connected in the upper and lower sheds of the barn. The two air-blocking structures 40 are symmetrically arranged vertically and vertically. The air-blocking structures 40 are used to change the direction of airflow.

[0053] The forced exhaust fan model 10 uses Kyushu POPLA.

[0054] In the above technical solution, the wind structure 40 includes a support rod 41, a guide plate 42, a first fixing block 43, and a second fixing block 44. The support rod 41 is a cubic strip structure. The first fixing block 43 is fixedly connected to the left side wall of the support rod 41, and the second fixing block 44 is fixed to the right side wall of the support rod 41. The top of the support rod 41 is connected to the guide plate 42 through a hinge. The guide plate 42 is a lightweight plate structure, and a torsion spring is provided inside the hinge.

[0055] Furthermore, in the above technical solution, the first fixing block 43 is an isosceles right triangle structure, and the right-angled side of the first fixing block 43 is fixedly connected to the side wall of the support rod 41. The support rod 41 and the first fixing block 43 form a flag-shaped structure.

[0056] Furthermore, in the above technical solution, the second fixing block 44 includes a first connecting part and a second connecting part. The first connecting part has a right-angled trapezoidal structure, and the second connecting part has a rectangular structure. The top surface of the right-angled trapezoid is fixedly connected to the side wall of the support rod 41, and the bottom edge of the right-angled trapezoid is fixedly connected to the long side of the rectangle.

[0057] Furthermore, in the above technical solution, the length of the lower base of the right trapezoid of the first connecting part is the same as the length of the long side of the rectangle of the second connecting part, and the surface where the short side of the second connecting part is located is flush with the upper top surface of the support rod 41.

[0058] Furthermore, in the above technical solution, the hypotenuse of the isosceles right triangle structure of the first fixing block 43 is provided with multiple heat dissipation holes. The heat dissipation holes are used to increase the heat dissipation effect of the airflow and improve the temperature uniformity in the baking room.

[0059] Furthermore, in the above technical solution, the rectangular structure of the second connecting part of the second fixing block 44 is provided with multiple grooves. The grooves are used to increase the disturbance of the airflow and improve the mixing effect of the airflow, thereby improving the uniformity of the flue-cured tobacco.

[0060] Furthermore, in the above technical solution, the surface of the guide plate 42 is coated with an anti-corrosion coating, which is used to prevent the guide plate 42 from corroding in a high temperature and high humidity environment.

[0061] The flow guiding structure 50 includes multiple arc-shaped flow guiding vanes, which are evenly distributed along the circumference of the inner wall of the forced exhaust fan. Each flow guiding vane can rotate around its radial axis, and the angle of the flow guiding vane is in the range of 0-45°. The surface of the flow guiding vane is smooth and the cross-section is streamlined. The back of the flow guiding vane is fixedly connected to one end of the connecting rod. The connecting rod 60 passes through the side wall of the forced exhaust fan and is rotatably connected to the side wall of the forced exhaust fan. The other end of the connecting rod 60 is fixedly connected to an adjustment terminal, and a scale is provided on the outer wall of the forced exhaust fan corresponding to the adjustment terminal.

[0062] The rotation angle of the connecting rod 60 is fixed by friction between the connecting rod 60 and the side wall of the forced exhaust fan.

[0063] Furthermore, in the above technical solution, the upper surface of the guide plate 42 is provided with a curved groove, and the curvature of the curved groove near the support rod 41 is less than the curvature of the original support rod 41; the curved groove structure can more effectively reflect the airflow in multiple directions, realize the step-by-step guidance and diffusion of the airflow, and reduce the turbulence of the airflow.

[0064] Furthermore, in the above technical solution, the upper surface of the guide plate 42 is provided with a plurality of tiny protrusions, which are irregularly arranged to increase the roughness of the guide plate surface, change the flow state of the airflow on the guide plate surface, and enhance the mixing and guiding effect of the airflow.

[0065] Sensors are installed inside the curing chamber to monitor the temperature, humidity, and wind speed in real time. The data is transmitted to a control unit connected to the forward and reverse rotation controller. The control unit automatically adjusts the speed and forward / reverse rotation of the forced exhaust fan, as well as the angle of the airflow deflector, based on the sensor data to achieve precise control within the curing chamber.

[0066] The control unit employs a digital temperature sensor and a high-performance microcontroller design, with a built-in roasting curve to adapt to the roasting of different types of tobacco leaves in different regions. The touchscreen controller is simple and easy to operate. Simultaneously, the control unit has comprehensive safety protection functions, such as overcurrent protection, lightning protection, and output short-circuit protection, ensuring the safety of the roasting process and equipment. The entire system is also additionally equipped with motor overload protection, which automatically cuts off the power supply to the circulating fan in the event of phase loss or overload, preventing equipment damage.

[0067] The controller can communicate with the frequency converter via an RS485 networking interface and a frequency converter communication interface to control the speed of the forced exhaust fan 10. It is equipped with a voice alarm function. Adding internet communication functionality allows operators to monitor the drying chamber status in real time via mobile phones or other remote devices, and to promptly alarm and handle any abnormalities. A backup battery is provided for convenient monitoring of the dry and wet bulb temperatures inside the drying chamber during power outages.

[0068] The settings are as follows: Before 45℃, rotate clockwise for 30 minutes and counterclockwise for 30 minutes; from 45℃ to 55℃, rotate clockwise for 55 minutes and counterclockwise for 5 minutes; from 55℃ to 60℃, rotate clockwise for 54 minutes and counterclockwise for 5 minutes; after 60℃, rotate clockwise for 30 minutes and counterclockwise for 30 minutes.

[0069] like Figure 13 The diagram shows a forced exhaust fan reversing airflow upwards for air delivery. Figure 14 The diagram shows a forced exhaust fan rotating in the forward direction, with airflow descending upwards.

[0070] In use, the forced exhaust fan 10, its speed, and the timing of the airflow mode changes are remotely set on the control unit. The forced exhaust fan 10 starts and rotates forward at the speed preset for the baking stage, entering a downward airflow mode. After the preset forward / reverse alternation time is reached, the forced exhaust fan 10 decelerates and stops for one minute, then reverses under the control of the forward / reverse controller 30, entering an upward airflow mode. The two airflow modes alternate continuously until baking is complete. The unidirectional airflow contacts the guide plate 42 and, depending on the airflow volume, causes the guide plate 42 to rotate around the support rod 41. The support rod 41 guides and diffuses the airflow.

[0071] Specifically, the principle of this invention is as follows: a reversible forced exhaust fan 10 is used to generate two unidirectional airflows, thereby changing the airflow direction within the drying oven, avoiding dead zones, and promoting more comprehensive airflow circulation. Symmetrical anti-aircraft structures are installed at the top and bottom of the drying oven to further optimize the airflow circulation path by changing the airflow direction. Through special design of components such as guide plates and fixing blocks in the anti-aircraft structures, the airflow guiding, mixing, and heat dissipation effects are further enhanced.

[0072] The following is a specific embodiment 1

[0073] The baking location was the Dehong Bato baking barn complex, with four barns tested. Each barn was equipped with an additional cold air vent and a 350W forced exhaust fan, and a controller with forward and reverse rotation functions was replaced. Parameters at different stages were monitored on the control unit, and the specific parameters are shown in Table 1.

[0074] Table 1. Monitoring Table for Dry Bulb and Wet Bulb Temperatures

[0075]

[0076] Dry-bulb temperature refers to the air temperature measured directly with a regular thermometer. It reflects the degree of hotness or coldness of the air and is unaffected by moisture in the air. Wet-bulb temperature, on the other hand, is the temperature measured with a thermometer wrapped in damp gauze. The evaporation of moisture from the gauze carries away heat, causing the thermometer reading to drop. Wet-bulb temperature reflects the degree of air saturation, that is, the extent to which the air is close to saturation in terms of moisture content.

[0077] like Figure 2 The diagram shows the baking process curve, which is divided into two alternating modes: heating up and stabilizing. The red line represents the dry bulb temperature, the blue line represents the wet bulb temperature, and the area below the blue line represents the dwell time for each stage.

[0078] The control parameters for the forced exhaust fan under the control of the forward and reverse rotation controller are set, as are the forward and reverse rotation times. Forward rotation control is used when the system is stopped, and forward and reverse rotation control logic is enabled during normal operation. The temperature setting is used to segment the forward and reverse rotation time of the forced exhaust fan according to the target temperature set in the system. The three temperature points can divide the entire working process into a maximum of four segments. The system sequentially judges the condition starting from the first temperature parameter; once the condition is met, it does not continue to the next segment. Forward rotation time range: 1-250 minutes; Reverse rotation time range: Segment 1 is 1-250 minutes, others are 0-250 minutes; Upper temperature limit range: 10-99℃. See Table 2 for details.

[0079] Table 2 Parameter settings for forced exhaust fans at different time periods

[0080] Forward rotation time (min) Reverse time (min) Upper temperature limit (°C) Section 1: 30 30 43 Section Two: 40 30 55 Section 3: 40 20 68 Section Four: 30 30

[0081] The fan pause time is set to 60 seconds, and the pause time range for forward and reverse operation is 15-250 seconds;

[0082] Set reverse heating to 0, where 0 means reverse heating is not interfered with and 1 means reverse heating is disabled;

[0083] Set the temperature rise reversal permission to 0, where 0 means the temperature rise segment is prohibited from reversing, and 1 means the temperature rise segment is allowed to reverse.

[0084] The fan protection current is set to 6.0A, with a range of 1-20A.

[0085] The following table provides a comparison of the baking times for the four baking oven groups, as shown in Table 3:

[0086] Table 3 Comparison of Baking Time for Different Baking Barn Groups

[0087]

[0088] The data comparison above clearly shows that the forward and reverse rotation strong air drying process takes significantly less time than the traditional drying room.

[0089] Experimental results show that the yellowing process of flue-cured tobacco is more uniform compared to that in synchronous rotating curing barns. After 38℃, both the upper and lower parts of the tobacco leaves begin to yellow, a fundamental difference from the changes observed in traditional flue-cured tobacco. Comparing the effects of traditional curing on tobacco leaves of the same quality, the enhanced rotating curing method clearly produces brighter colors and indicates a higher grade. Figure 3 The diagram shows the temperature changes during different stages of tobacco curing.

[0090] The following table, Table 4, compares the baking fuels used in the four baking barns:

[0091] Table 4 Comparison of Fuel Consumption in Different Baking Barn Groups

[0092]

[0093] The data above shows that using fuel for forward and reverse rotation of the duct can save about 200 kg compared to normal baking.

[0094] The roasting process is still ongoing and is under control, requiring minimal adjustments.

[0095] Experiment Summary:

[0096] 1. The reverse-rotation matching cold air damper and strong exhaust fan can meet the airflow requirements of reverse-rotation baking.

[0097] 2. Both forward and reverse rotations should be performed within the stable temperature range; reverse rotation must be prohibited during the heating phase.

[0098] 3. The process requires a humidity level of 1 to 1.5 to prevent excessive humidity from causing cooking during the yellowing and settling stages.

[0099] The following is a specific example 2:

[0100] The tested tobacco variety was KRK26, and the tested tobacco leaves were mostly lower leaves with a small portion of middle leaves. Table 5 shows the information on the type of curing barn.

[0101] Table 5 Information on Curing Barn Types

[0102] name type No. 1 baking room Forward and reverse fan No. 2 baking room Forward and reverse fan No. 5 baking room Forward and reverse fan No. 15 baking room Reverse-rotating fan + temperature, humidity, and wind speed sensors No. 9 baking room Standard + temperature, humidity, and wind speed sensors

[0103] Table 6 shows the amount of biomass fuel consumed in the drying room and the drying schedule:

[0104]

[0105] According to on-site records, due to human error (the tobacco leaves were too thickly bound with tobacco clips by the tobacco farmers), the actual curing time in curing barn No. 15 was 207.4 hours (extended by 24 hours). Therefore, theoretically, the curing time in curing barn No. 15 should have been 183.4 hours.

[0106] Results and Analysis: The biomass fuel consumption and baking time of the four rotating fan drying barns were both lower than those of barn No. 9. Regarding biomass fuel consumption, the order of the barns was 1 < 2 < 5 < 15 < 9. Under this order, the rotating fan drying barns reduced biomass fuel consumption by 20.74%, 20.30%, 19.68%, and 18.77% respectively compared to barn No. 9, with an average reduction of 139.11 kg. Regarding biomass fuel consumption, the order of the barns was 15 < 1 < 2 < 5 < 9. Under this order, the rotating fan drying barns shortened baking time by 2.66%, 1.82%, 1.04%, and 4.38% respectively compared to barn No. 9, with an average shortening of 4.78 hours.

[0107] Table 7 shows the analysis of the weight and economic traits of the first-cured tobacco leaves:

[0108]

[0109] Because there are many tobacco farmers producing tobacco, and a limited number of people to collect statistics on economic traits, data for three tobacco curing barns with forward and reverse fan operation are missing from the table.

[0110] Results and Analysis: The dry tobacco weight of all four curing barns with reversible fans was higher than that of barn No. 9, with barn No. 15 showing better economic performance than barn No. 9. In terms of dry tobacco weight, the order of the barns was 9 < 15 < 2 < 1 < 5. Under this order, the reversible fan barns increased the dry tobacco weight by 9.65%, 22.81%, 28.95%, and 49.12% respectively compared to barn No. 9, with an average increase of 0.38 kg / barn. In terms of economic performance, barn No. 15 increased the proportion of high-grade tobacco, average price, yield, and output value by 28.88%, 6.09% (1.97 yuan), 9.65% (19.36 kg / mu), and 16.33% (1059.50 yuan / mu) respectively compared to barn No. 9.

[0111] Table 8 shows the baking data test results for oven No. 11.

[0112]

[0113]

[0114] like Figure 4 The figure shows the drying and wet temperature curves for the baking process in baking room No. 1. Figure 5 The image shows a comparison of the baking processes in baking room No. 1 and baking room No. 9.

[0115] Table 9 shows the baking data detection table for oven No. 2.

[0116]

[0117]

[0118] like Figure 6 The figure shows the dry and wet temperature curves for the baking process in baking room No. 2. Figure 7 The image shows a comparison of the baking processes in baking room No. 2 and baking room No. 9.

[0119] Table 10 shows the baking data test results for oven No. 5.

[0120]

[0121]

[0122] like Figure 8 The figure shows the dry and wet temperature curves for the baking process in baking room No. 5. Figure 9The diagram shows a comparison of the baking processes in ovens 5 and 9. Before 40:00, the baking processes in ovens 5 and 9 were the same; after 40:00, the wet-bulb temperature in oven 5 was lower than that in oven 9.

[0123] Table 11 shows the baking data test results for baking room No. 15.

[0124]

[0125]

[0126] like Figure 10 The figure shows the drying and wet temperature curves for the baking process in baking room No. 15. Figure 11 The image shows a comparison of the baking processes in baking room No. 15 and baking room No. 9.

[0127] Before 40 hours, the baking processes in drying ovens No. 15 and No. 9 were the same. The wet-bulb temperature in drying oven No. 15 showed a relatively gradual trend from 40 to 110 hours, but increased significantly after 110 hours. The wet-bulb temperature in drying oven No. 9 increased slightly faster from 40 to 150 hours. The dry-bulb temperature in drying oven No. 15 rose at a faster rate, therefore the time required for each stage was less than that in drying oven No. 9.

[0128] Table 12 shows the baking data test results for baking room No. 9.

[0129]

[0130] like Figure 12 The figure shows the drying and wet temperature curves during the baking process in oven No. 9.

[0131] Anomaly record during testing: In curing barn No. 15, the total curing time was extended because the tobacco leaves woven by the tobacco farmers using tobacco clips were too thick.

[0132] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A high-efficiency energy-saving forward-reverse fan for a tobacco leaf bulk curing barn, comprising a curing barn, a strong exhaust fan fixed on the wall of the curing barn, and a cold air inlet door below the strong exhaust fan, the cold air inlet door being used for discharging moisture in the curing barn, a forward-reverse controller being fixed on the strong exhaust fan, the strong exhaust fan being electrically connected with the forward-reverse controller, and the strong exhaust fan being used for generating two one-way airflows to promote air circulation; characterized in that, The upper and lower sections of the drying oven have two detachable air-blocking structures, which are symmetrically arranged. These structures are used to change the direction of airflow. The inner wall of the forced exhaust fan has a guide structure, which is used to form a gas flow channel.

2. A high efficiency energy saving forward-reverse rotation blower for tobacco dense curing barn according to claim 1, characterized in that, The wind-resistant structure includes a support rod, a guide plate, a first fixing block, and a second fixing block. The support rod is a cubic strip structure. The first fixing block is fixedly connected to the left side wall of the support rod, and the second fixing block is fixed to the right side wall of the support rod. The top of the support rod is connected to the guide plate via a hinge. The guide plate is a lightweight plate structure, and a torsion spring is installed inside the hinge. The surface of the guide plate is coated with an anti-corrosion coating to prevent corrosion of the guide plate in high temperature and high humidity environments.

3. A high efficiency energy saving forward-reverse rotation blower for tobacco dense curing barn according to claim 2, characterized in that, The first fixing block is an isosceles right triangle structure, with the right-angled side of the first fixing block being fixedly connected to the side wall of the support rod. The support rod and the first fixing block form a flag-shaped structure.

4. The high-efficiency energy-saving forward and reverse rotating fan for intensive tobacco curing barns according to claim 3, characterized in that, The second fixing block includes a first connecting part and a second connecting part. The first connecting part has a right-angled trapezoidal structure, and the second connecting part has a rectangular structure. The top surface of the right-angled trapezoid is fixedly connected to the side wall of the support rod, and the bottom edge of the right-angled trapezoid is fixedly connected to the long side of the rectangle.

5. A high-efficiency, energy-saving forward and reverse rotating fan for a dense tobacco curing barn according to claim 4, characterized in that, The length of the lower base of the right trapezoid of the first connecting part is the same as the length of the long side of the rectangle of the second connecting part, and the surface of the short side of the second connecting part is flush with the top surface of the support rod.

6. A high-efficiency energy-saving forward and reverse rotating fan for intensive tobacco curing barns according to claim 5, characterized in that, The first fixing block has multiple heat dissipation holes on the hypotenuse of its isosceles right triangle structure. These holes are used to increase the heat dissipation effect of the airflow and improve the temperature uniformity inside the baking oven.

7. A high-efficiency, energy-saving forward and reverse rotating fan for intensive tobacco curing barns according to claim 6, characterized in that, The rectangular structure of the second connecting part of the second fixing block is provided with multiple grooves. The grooves are used to increase the disturbance of the airflow and improve the mixing effect of the airflow, thereby improving the uniformity of the flue-cured tobacco.

8. A high-efficiency energy-saving forward and reverse rotating fan for intensive tobacco curing barns according to claim 7, characterized in that, The flow guiding structure includes multiple arc-shaped flow guiding vanes, which are evenly distributed along the circumference of the inner wall of the forced exhaust fan. Each flow guiding vane can rotate around its radial axis, and the angle of the flow guiding vane ranges from 0 to 45°. The surface of the flow guiding vane is smooth, and the cross-section has a streamlined structure. The back of the flow guiding vane is fixedly connected to one end of a connecting rod. The connecting rod passes through the side wall of the forced exhaust fan and is rotatably connected to the side wall of the forced exhaust fan. An adjustment terminal is fixedly connected to the other end of the connecting rod, and a scale is set on the outer wall of the forced exhaust fan corresponding to the adjustment terminal.

9. A high-efficiency, energy-saving forward and reverse rotating fan for a dense tobacco curing barn according to claim 8, characterized in that, The upper surface of the deflector is provided with curved grooves. The curvature of the grooves near the support rod is less than that of the original support rod. The curved groove structure can more effectively reflect the airflow in multiple directions, realize the step-by-step guidance and diffusion of the airflow, and reduce the turbulence of the airflow.

10. A high-efficiency, energy-saving forward and reverse rotating fan for a dense tobacco curing barn according to claim 8, characterized in that, The upper surface of the deflector is provided with multiple tiny protrusions arranged irregularly to increase the surface roughness of the deflector, change the flow state of the airflow on the surface of the deflector, and enhance the mixing and guiding effect of the airflow.

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