Solar industrial pepper drying system

Abstract

The invention belongs to the technical field of solar drying, and particularly relates to a solar industrial pepper drying system. Comprising a solar heat collector, an air pipe, a fan, a box body drying tunnel, a charging tray and a track, the rail is arranged at the bottom of the box body drying tunnel, the charging tray is arranged on the rail, the solar heat collector absorbs solar radiation and heats air, and the fan drives hot air to enter the box body drying tunnel through the air pipe; particularly, the box body drying tunnel is of an inverted isosceles trapezoid structure, a plurality of hot air through holes are formed in the lower bottom edge of the box body drying tunnel and the charging tray, and the air pipe is communicated with the hot air through holes. A bottom air supply structure is adopted, and through holes are formed in the bottoms of the charging tray and the box body, so that hot air penetrates through the pepper root area from bottom to top, particularly pepper stems attached to the bottom of the charging tray are dried in an intensified mode, the technical bottleneck that the stems are difficult to dry in a traditional drying mode is solved, and drying uniformity is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of solar drying, and particularly relates to a solar industrial pepper drying system. BACKGROUND

[0002] Industrial pepper is a kind of pepper variety specially cultivated and screened, which has the characteristics of high yield, strong spiciness, good drying performance, etc., and is widely used in food seasoning processing, chili sauce preparation, chili oil extraction, natural pigment extraction (such as capsanthin), and pesticide, feed additive and other industrial fields. Compared with fresh pepper, industrial pepper is usually stored and processed in the form of dried products, so the drying quality directly affects the color, flavor, active ingredients and subsequent processing performance of the products.

[0003] With the development of green agriculture and clean energy, solar drying technology is widely promoted in the field of industrial pepper drying due to its energy saving, low carbon, low cost and other advantages. Solar drying not only avoids the problems of high energy consumption, high cost and serious pollution caused by traditional coal stove and electric heating methods, but also has relatively soft drying temperature, which is suitable for maintaining bright color of pepper, reducing degradation of capsaicin, improving the quality of dried products and economic added value, and is particularly suitable for use in pepper producing areas with sufficient sunlight in northwest and southwest China.

[0004] However, the existing solar drying system mostly adopts updraft or horizontal air supply structure, and the hot air is mainly concentrated on the surface and middle part of the pepper. The root and stem of the pepper are tightly attached to the bottom of the tray, and the airflow is difficult to penetrate, resulting in slow drying speed and high moisture content in this part, which is the most difficult area to dry in the whole drying process, seriously restricting the drying efficiency and product consistency. In industrial continuous drying applications, this problem is particularly prominent, often leading to prolonged drying time, increased energy consumption, large quality fluctuations, and even the need for manual turning or secondary drying treatment, increasing labor costs and operation complexity. Therefore, there is an urgent need for a new type of solar pepper drying system with optimized structure to improve the drying efficiency of the pepper stem and solve the technical problem of incomplete drying at the bottom. SUMMARY

[0005] To solve the above problems, the present application provides a solar industrial pepper drying system, which comprises a solar heat collector, an air pipe, a fan, a box drying channel, a tray and a track. The track is placed at the bottom of the box drying channel, the tray is placed on the track, the solar heat collector absorbs solar radiation and heats air, and the fan drives hot air to enter the inside of the box drying channel through the air pipe. In particular, the box drying channel has an inverted isosceles trapezoidal structure, and the lower base of the box drying channel and the tray are both provided with a plurality of hot air through holes, and the air pipe is connected to the hot air through holes.

[0006] The present application is characterized in that the box drying tunnel is in an inverted isosceles trapezoidal structure, and the hot air passes through the holes in the lower bottom and the trays from bottom to top, thereby enhancing the heating effect on the bottom of the peppers, especially the stems. In the traditional side-blowing or top-blowing method, the stems are usually located at the bottom of the tray and are in close contact with the bearing surface, making it difficult to effectively dry this part. The present application uses a bottom air supply structure, and the hot air directly passes through the holes in the tray to act on the stems. At the same time, local disturbance can make the peppers slightly sway, further reducing the thermal resistance between the stems and the tray, enhancing the penetration and wrapping of the hot air flow on the stems, and significantly improving the drying rate and overall drying uniformity of the stems. In addition, the inverted isosceles trapezoidal structure of the box drying tunnel further optimizes the effect of hot air: when the hot air passes through the holes in the lower bottom and the trays from bottom to top into the drying cavity, part of the hot air flow produces slight disturbance at the bottom of the peppers, causing part of the peppers to be affected by the air flow buoyancy and temporarily sway or roll. When the peppers recover from the disturbed state and fall down, due to the inclined walls on both sides of the inverted isosceles trapezoidal structure, part of the peppers will slide to the inclined walls on both sides of the box drying tunnel. Under the guidance of this structure, the peppers can naturally disperse and adhere to the inclined walls on both sides, significantly expanding the contact area between the peppers and the hot air flow. The hot air rises in a diffused manner in the inverted trapezoidal structure, not only penetrating the central area, but also flowing along the side walls, thereby further drying the peppers adhering to the side walls. This design allows the peppers to undergo a multiple thermal action process of "bottom penetration + disturbance rolling + side wall attachment", which is particularly helpful in improving the drying uniformity of the stems and shadowed parts of the peppers and enhancing the overall drying efficiency and quality consistency.

[0007] Furthermore, the angle between the inner walls on both sides of the inverted isosceles trapezoid and the lower bottom is 45 o to 75 o . First, this angle range ensures that the hot air can form a concentrated heat accumulation area at the bottom of the box, and helps the hot flow to uniformly diffuse and rise to both sides in the cavity, thereby improving the distribution uniformity of the heat field inside the box; second, when the hot air disturbance causes part of the peppers to roll or slide to the inclined surfaces on both sides, the inclined angle of 45 o to 75 o allows the peppers to naturally adhere or temporarily stay on the side wall surface, and is not easy to quickly roll down to the bottom, prolonging the heating time of the hot air flow on the side of the peppers and the stems.

[0008] Further, the tray is slidably arranged on the track and slides along the length direction of the box drying channel, that is, moves in the direction orthogonal to the vertical axis of the hot air rising direction. On the one hand, it is convenient for the operator to push or pull the tray loaded with the peppers in sequence to realize the feeding, discharging, turning or periodic replacement operation in the drying process, thereby improving the continuity and flexibility of the system operation; on the other hand, in the actual drying process, the tray can be periodically pushed to slide back and forth along the track, so that the peppers realize dynamic adjustment in position in the hot air flow field, thereby avoiding the uneven drying problem caused by local uneven heat flow intensity or fixed accumulation of the tray, especially being beneficial to the heat field redistribution and uniform drying of the pepper stem part; in addition, the structure can also be combined with an automatic pushing device to realize the energy-saving intelligent upgrading of the solar drying system.

[0009] Further, the material of the tray is 304 stainless steel. The 304 stainless steel has excellent high-temperature resistance and can withstand the action of hot air of 40-70℃ in the solar drying process for a long time without deformation or release of harmful substances, thereby ensuring the thermal stability and safety of the drying environment; secondly, the material has good corrosion resistance and oxidation resistance, and is not easy to be corroded even under the condition of high humidity, high salt or acidic pepper juice contact, thereby prolonging the service life; thirdly, the surface of the 304 stainless steel is smooth, which is convenient for cleaning and disinfection, meets the hygiene requirements in the food-grade drying process, and avoids the adsorption of peculiar smell or pollutants by the peppers during the drying process.

[0010] Further, the box drying channel is a multi-layer composite structure, which comprises an outer shell layer, an insulation layer and an inner liner layer from outside to inside. The material of the outer shell layer is galvanized steel sheet, which has good mechanical strength and weather resistance, can effectively resist outdoor wind and rain, ultraviolet rays and mechanical impact, and ensure the stability and service life of the overall structure of the equipment; the material of the insulation layer is polyurethane foam, which has low thermal conductivity and excellent heat insulation performance, can significantly reduce the heat loss to the outside, improve the heat energy utilization rate, reduce the energy consumption, and ensure the temperature stability of the drying process; the material of the inner liner layer is 304 stainless steel, which has the advantages of high temperature resistance, corrosion resistance, easy cleaning and compliance with food contact safety standards, can directly contact with the peppers and hot and humid air, and ensures the hygiene and safety of the drying process and the product quality. The three-layer structure cooperates to realize stable structure, protection and durability, and also meets the requirements of heat preservation, energy saving and food-grade drying environment, thereby improving the thermal efficiency, service life and product safety of the entire solar pepper drying system. Further, the top of the box drying tunnel is provided with a moisture discharge hole for discharging the water vapor released during the drying of the peppers. Hot air enters from the bottom of the box, penetrates the tray and the peppers, and pushes the moisture to evaporate upward from the bottom. The steam rises with the airflow to the top of the drying tunnel and is discharged from the system through the moisture discharge hole, thereby realizing a continuous and efficient moisture migration channel. This structure utilizes the natural convection law of "hot air rising + top moisture discharge", avoiding the accumulation of water vapor in the box, preventing problems such as reduced drying rate, moisture regain, discoloration or mold of the peppers caused by local humidity increase. At the same time, timely moisture removal can maintain a stable drying environment in the box, increase the evaporation driving force between hot air and materials, promote the escape of deep moisture in the peppers, especially in the stem area, and improve the drying rate and uniformity, which helps to obtain higher quality and more stable moisture content of dried pepper products.

[0011] Further, the shape of the hot air through hole is rectangular, and the long side of the rectangle is along the moving direction of the tray. This structure design forms a longer airflow release path in the moving direction of the tray, causing a slight speed gradient and local disturbance in the length direction when the hot air passes through the through hole. The disturbance caused by this speed difference can cause some peppers to roll or swing slightly, especially the bottom or stem area of the peppers that are originally attached to the surface of the tray, which reduces the contact area and makes it easier to accept direct heating of hot air. In this way, not only does it enhance the contact efficiency between the surface of the peppers and the hot airflow, but it is also particularly beneficial to promoting uniform drying of the pepper stem, thereby improving overall drying uniformity and efficiency.

[0012] Further, the width of the rectangle is less than the width of the pepper, and the length of the rectangle is greater than the length of the pepper. The width being less than the cross-sectional dimension of the pepper can effectively prevent the pepper from falling into the through hole during the drying process due to hot air disturbance or tray movement, ensuring the stability and safety of the drying process; the length being greater than the length of the pepper body allows the hot air to have a larger longitudinal flow cross section when passing through the through hole into the box drying tunnel, thereby forming a longer airflow channel in the direction of the peppers, which is beneficial to forming directional hot air disturbance along the length of the peppers, increasing the coverage area and the possibility of turning over between the peppers and the hot airflow, and particularly enhancing the heating penetration effect on the bottom and stem of the peppers.

[0013] Further, the surface of the tray is provided with a spike array. Firstly, the spike array can locally raise the chilies, greatly reducing the direct contact area of the chilies with the bottom surface of the tray, avoiding the chilies from being attached to the surface of the tray for a long time, and thus reducing the thermal resistance and water migration resistance; secondly, the chilies are distributed on the spikes to form a point contact support structure, which facilitates the hot air to penetrate the chilies from multiple directions (bottom, side, gap), realizes a more three-dimensional drying environment, and is especially beneficial to the effective heating and moisture evaporation of the traditional "dead angle" area such as the stem part of the chilies; in addition, the spikes also have a certain anti-skid and separation function, which prevents the chilies from being concentrated and accumulated under the disturbance of hot air, helps to maintain the ventilation gap between the chilies, and enhances the heat flow circulation and drying uniformity. Therefore, the spike array arranged on the surface of the tray not only optimizes the spatial relationship between the chilies and the hot air, but also significantly improves the penetration, drying efficiency and quality consistency of the chilies during the drying process. Further, the spike array arranged on the surface of the tray not only supports the chilies and reduces the contact area with the bottom, but also has a physical effect of slightly penetrating the surface of the chilies. During the drying process, the spikes can partially penetrate the chilies, especially the stem part or the area with thick skin, form small perforations or indentations without damaging the overall structure, thereby destroying the local dense structure and enhancing the air permeability and moisture diffusion channel of the area. This "physical micro-penetration" effect helps to accelerate the migration of internal moisture to the surface, especially for the traditional difficult-to-dry parts such as the stem part of the chilies, which further improves the drying rate and drying uniformity. Therefore, the spike structure not only optimizes the air flow contact, but also enhances the overall dehydration efficiency of the chilies through the slight penetration effect.

[0014] Further, a plurality of parallel convex stripes extending along the slope direction are arranged on the two inner walls of the inverted isosceles trapezoid. This structure not only has the effect of guiding the hot air to rise along the side wall and enhancing the heat convection path, but also provides directional support and distribution adjustment function when the chilies slide down to the slope. When the hot air is disturbed or turned over, part of the chilies slide down to the inclined side wall, the convex stripes can prevent the chilies from sliding down to the bottom quickly, and make them stay or adhere to the inclined wall for a short time. At this time, the chilies usually fall on the convex stripes with the stem part facing down, and the gap formed between the convex stripes is just suitable for the hot air to cover the bottom of the chilies from bottom to top, realizing the concentrated heating and rapid drying of the stem part of the chilies. Therefore, the existence of the convex stripes not only enhances the stability and dispersibility of the chilies on the side wall, but also regulates the falling posture of the chilies and the angle of the hot air, further improving the drying efficiency and uniformity of the stem part of the chilies.

[0015] The beneficial effects of the present application are as follows: (1) The present application adopts a bottom air supply structure, and a through hole is arranged on the bottom of the tray and the box, so that the hot air penetrates the root area of the chilies from bottom to top, especially the stem part of the chilies attached to the bottom of the tray, which is intensively dried, solving the technical bottleneck of "difficult-to-dry stem part" in the traditional drying method, and improving the drying uniformity.

[0016] (2) The inverted isosceles trapezoidal structure cooperates with the slope airflow guide, further enhances the hot air covering and penetrating effect, promotes the uniform distribution of the hot field, and improves the overall drying efficiency.

[0017] (3) The hot air through hole is designed as a rectangle distributed along the moving direction of the material disc, the airflow velocity forms a slight disturbance, which is beneficial to slightly turning the peppers, and improves the stem part drying efficiency.

[0018] (4) The sharp material disc structure reduces the contact area of the peppers and possibly slightly stimulates the epidermis, accelerates the water escape, and enhances the three-dimensional heat exchange effect.

[0019] (5) The parallel convex strips are arranged on the inner wall of the slope, so that the sliding peppers are attached to the slope in a "stem down" state, which is beneficial to the direct action of hot air on the difficult drying part, and improves the stem part drying efficiency.

[0020] In summary, the present application has good application prospects in the field of solar drying technology. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a schematic view of the box drying channel, material disc, track and air pipe.

[0022] In the figure: 1, box drying channel; 2, track; 3, material disc; 4, air pipe; 11, lower bottom. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the present application more clear and explicit, the present application is further described in detail below with reference to the drawings and examples.

[0024] Example 1 The present embodiment provides a solar-based industrial pepper drying system, which is suitable for batch drying of fresh industrial peppers, and is particularly designed for structural optimization to solve the problem of difficult drying of pepper stems. The system mainly includes: a solar collector, an air pipe 4, a fan, a box drying channel 1, a material disc 3 and a track 2. Figure 1 The schematic view of the box drying channel 1, the material disc 3, the track 2 and the air pipe 4 is given. The related elements constituting the system are introduced as follows: I. Solar collector The solar collector is arranged in a sufficient light position above the system, which is a flat plate type or vacuum tube type heat collecting device, the outer shell is made of aluminum alloy material, and the surface is provided with an anti-reflection glass plate. The solar collector is internally provided with heat absorbing coated heat collecting pipes connected with a circulating heat conducting liquid or air channel.

[0025] In the system, the solar collector is used to absorb solar radiation and convert it into heat energy, and the hot air supply is achieved by air heating. The generated hot air is transported to the drying cavity through the downstream air pipe, which is the core energy source of the system.

[0026] II. Air pipe and fan The air pipe 4 is made of high-temperature-resistant aluminum foil composite hose or PVC heat-resistant hard pipe, with smooth interior to reduce air resistance. One end of the air pipe 4 is connected to the hot air outlet of the solar collector heating cavity, and the other end is connected to the hot air through hole of the lower bottom edge 11 of the box drying channel 1. A fan is connected in series in the middle of the air pipe 4.

[0027] The fan is a centrifugal hot air circulating fan with a rated power of about 200W, which can generate stable airflow to drive hot air to flow through the air pipe 4 into the bottom of the box drying channel 1. The fan has a speed regulation function to control the air supply speed and adjust the hot air flow and distribution in the drying cavity.

[0028] III. Box drying channel The box drying channel 1 is the drying cavity of the system, which adopts an inverted isosceles trapezoidal cross-sectional structure. In this structure, the lower bottom edge 11 is horizontally arranged, and the two side walls are inclined upward at an angle of 45 o -75 o to connect the top, which can be closed or provided with a moisture discharge port.

[0029] The outer shell of the box drying channel 1 is made of 1.2mm thick galvanized steel plate, which has good structural strength and wind and rain resistance; the insulation layer is 30mm thick polyurethane foam board with a thermal conductivity less than 0.02W / m·K, which can effectively insulate and keep warm; the inner liner is made of food-grade 304 stainless steel sheet with a thickness of about 1.0mm, which is corrosion-resistant and easy to clean, suitable for food drying.

[0030] A plurality of evenly distributed hot air through holes are arranged on the lower bottom edge 11 of the box drying channel 1, which are rectangular in shape, with the long side arranged along the length direction of the box drying channel 1 corresponding to the sliding direction of the tray 3. The hot air through holes are connected with the air outlet end of the air pipe 4 to form a hot air upward conveying channel.

[0031] A plurality of moisture discharge holes are provided on the top of the box drying channel 1 to discharge the water vapor generated during the drying process, avoiding the decrease of drying efficiency caused by high humidity in the cavity.

[0032] IV. Track and tray structure The track 2 is arranged above the lower bottom plate 11 of the box drying channel 1 and is laid along the length direction of the box drying channel 1, which is made of stainless steel profile and arranged in double tracks in parallel with the same spacing as the bottom pulley of the tray 3.

[0033] The tray 3 is slidably arranged on the track through a pulley structure, and is convenient for an operator to push or pull from one end. The tray 3 is a rectangular shallow dish structure, the frame is welded by stainless steel, and a horizontal reinforcing rib is arranged in the tray 3 to increase the structural rigidity.

[0034] A plurality of rectangular hot air through holes are arranged at the bottom of the tray 3 and are aligned with the through holes in the lower bottom edge 11 of the box drying channel 1, the length of the through holes is greater than the length of a single pepper, and the width of the through holes is less than the width of the pepper, so that the pepper is prevented from falling and the hot air is ensured to smoothly penetrate the pepper stem part. The size of the lower bottom surface of the hot air through hole is greater than the size of the upper surface thereof.

[0035] The solar energy industrial pepper drying system absorbs solar radiation and heats air through the solar heat collector, forms a stable air flow driven by the fan, is transported to the bottom of the box drying channel 1 along the air pipe 4, and directly enters the inside of the drying cavity through the bottom hot air through hole. The hot air penetrates the tray 3 and the pepper stack from bottom to top, especially the through holes between the tray 3 and the pepper concentrate the heating of the pepper stem part, and the processing efficiency of the traditional difficult drying area is strengthened. The inverted isosceles trapezoidal structure makes the hot air flow have an upward diffusion trend in the cavity, guides part of the peppers to slide to the two sides of the inclined surface, further contacts the hot air, and enhances the all-around drying effect. The top is provided with a moisture discharge hole, which can discharge water vapor in time, maintain a low-humidity environment in the cavity, and improve the drying efficiency and uniformity. The overall system uses solar energy as a heat source, is energy-saving and environment-friendly, has a cooperative structure, uniform drying, and is especially suitable for batch drying of industrial peppers which are difficult to dry.

[0036] To further improve the drying effect, the fan control mode is a pulse air supply structure, the fan is periodically turned on and off through the controller, intermittent high-intensity air flow is formed, and periodic gusts are generated at the hot air through hole at the lower bottom of the box drying channel 1. When the high-pressure hot air pulse passes through the bottom through hole, the peppers in the tray can be greatly lifted and temporarily suspended in the air, so that the peppers produce a fluidized motion process of rolling, floating and falling back. The design enhances the wrapping and flushing effect of the hot air on the pepper stem part and the inner layer of the pepper, improves the drying uniformity and speed, and especially solves the problem that the stem part is attached to the bottom and dried slowly in the traditional drying. At the same time, the dynamic disturbance can prevent the peppers from sticking and clumping, improve the overall drying quality and yield, and is a key improvement scheme for promoting the full and sufficient drying of the peppers.

[0037] Example 2 On the basis of embodiment 1, the structure of the tray 3 is optimized, a plurality of spike arrays are uniformly arranged on the surface of the tray 3, the spike height is 5-10 mm, and the spike is integrally punched or welded by 304 stainless steel and arranged in a regular matrix structure. The spike is used to slightly lift the pepper, reduce the contact area of the pepper with the bottom surface of the tray, enhance the penetration of hot air on the bottom and stem part of the pepper, and significantly improve the heat exchange efficiency. At the same time, part of the spike can slightly push or pierce into the stem area of the pepper, and generate micro-cracks or pressure concentration evaporation points during the drying process, which helps to accelerate the moisture escape of the stem part. In addition, under the action of pulse air supply or gust, the spike can also break the stacking structure of the pepper, enhance the rolling and disturbance effect, and make the pepper dry more fully and uniformly. This structure is especially suitable for improving the drying rate of the stem part of the pepper, and further improving the efficiency and product quality of the entire drying system.

[0038] Preferably, the spike array at the bottom of the tray is designed to be relatively higher near the hot air through hole, and the spike height gradually decreases from the center of the through hole to the periphery, forming a locally convex conical support structure. The height of the spike above the through hole is 8-10 mm, the edge area is 6-8 mm, and the periphery is reduced to 3-5 mm. This structure can lift the pepper above the through hole area, especially the stem part, so that it is fully exposed to the hot air flow, reduces the shielding and contact area, and enhances the bottom drying effect. At the same time, due to the local airflow disturbance caused by the height difference of the spike, the hot air forms a stronger upward flow and rolling force in this area, promoting the pepper to roll, and making the drying more uniform. In addition, this design can also inhibit the short-circuit flow of hot air after direct penetration, so that the heat energy is fully diffused and retained in the pepper layer, further improving the overall drying efficiency.

[0039] Embodiment 3 On the basis of embodiment 2, the internal structure of the box drying channel 1 is further optimized, a plurality of parallel ridge structures extending along the slope direction are arranged on the surface of the inner wall of the two sides of the inverted isosceles trapezoidal drying channel, so as to improve the heating state and residence form of the pepper during sliding on the slope.

[0040] The ridge is a long strip-shaped protrusion made of stainless steel material, uniformly arranged along the slope direction of the two sides of the box drying channel, the height of each ridge is 5-10 mm, the width is 10-15 mm, and the length can cover more than 60% of the height of the slope. The ridge is fixed on the surface of the inner wall by welding or molding, and is arranged in coordination with the direction of hot air flow, which does not hinder the diffusion of hot air, and can guide the distribution of peppers.

[0041] During the drying process, the hot air at the bottom is sent upward through the hot air through holes, blowing some of the peppers up, and some of the peppers slide down to the two sides of the inverted trapezoidal inclined surface under the combined action of airflow and gravity. Because the inclined surface is provided with a convex strip structure, the peppers will be blocked, stagnated and temporarily stopped by the convex strip during the sliding process, making it easier to adhere to the surface of the inclined surface with the stem downward. At this time, the hot air rises through the through hole and forms a stable flow field near the inclined surface, which can continuously heat the peppers stopped on the convex strip and strengthen the heating and dehydration of the stem area.

[0042] In addition, the convex strip also has the function of "scattering" the sliding peppers, preventing them from forming dense accumulation on the inclined surface, helping the peppers to be distributed in a single layer, and further improving the drying uniformity and ventilation effect. Overall, by introducing the convex strip structure on the inclined surface, the residence time of the peppers in the hot air path is prolonged, the posture of the peppers is controlled, and the rapid evaporation of the water in the bottom and stem is promoted, thereby improving the drying efficiency and consistency of the finished product.

[0043] Preferably, the multiple convex strips provided on the inverted isosceles trapezoidal side wall of the box drying tunnel 1 gradually increase in height from top to bottom, for example, the top convex strip is 5mm high, the middle is 15mm high, and the bottom is 30mm high. This height gradient design helps to guide the hot air to form layered disturbance, improving the heating uniformity of peppers at different heights; at the same time, during the sliding process of the peppers, the gradually increasing convex strips can effectively hold the sliding peppers, especially the peppers with the stem downward, which are stopped at the lower convex strips, prolonging the contact time of the stem with the hot air, thereby significantly enhancing the drying rate of the stem. In addition, the high convex strip can also increase the complexity of the local airflow path, inhibit the short circuit of the hot air, strengthen the heating and dehumidification effect on the lower layer, and overall improve the drying efficiency and uniformity.

[0044] Embodiment 4 On the basis of embodiments 1-3, sensors and automatic control systems are introduced to realize intelligent regulation and control of the pepper drying process. Specifically, a plurality of sensors are arranged inside the box drying tunnel 1, including temperature sensors, humidity sensors, hot air flow rate sensors, and optional pepper moisture content sensors. The temperature sensors are evenly arranged along the length direction of the box drying tunnel 1, mainly arranged at the top and the side wall position, for monitoring the hot air temperature distribution. The humidity sensors are arranged near the top exhaust hole and in the middle of the box drying tunnel 1, for real-time detection of water vapor concentration and judgment of the exhaust effect. The hot air flow rate sensor is installed at the outlet of the air pipe 4 for monitoring the air supply intensity and its stability; the optional pepper moisture content sensor adopts a near-infrared or capacitive structure and is installed near the upper position of the tray for estimating the drying progress.

[0045] The data of the above-mentioned sensor is transmitted to a central control module by wireless or wired mode, the control system is constructed by using an STM32 single-chip microcomputer or an embedded PLC platform, and multiple control strategies are preset: when the temperature exceeds the preset value, the fan speed is automatically reduced or the air supply is suspended to prevent overheating; when the humidity is not discharged well, the system automatically prolongs the dehumidification time or adjusts the opening degree of the dehumidification hole; when the water content of the peppers is close to the target value, the system is automatically switched to a low-temperature maintenance mode to prevent overdrying. In addition, the system also supports user-defined operation parameters, which can be set and remotely monitored through an external control panel or a mobile terminal interface to realize fine setting of temperature, time, and humidity targets.

[0046] Through the intelligent control system, the drying process can automatically adapt to the water content of different batches of peppers and environmental changes, effectively improving the drying uniformity and system energy efficiency, reducing manual intervention, and enhancing the stability and drying quality of the overall operation.

[0047] In summary, the present application provides a solar industrial pepper drying system with optimized structure and significantly improved efficiency. To solve the problem of difficult drying of pepper stems, the present application innovatively uses an inverted isosceles trapezoidal box drying channel 1, a bottom hot air through hole, a sliding tray 3, a spike array, and a slope convex strip structure to realize the concentrated penetration of hot air from bottom to top, and the formation of pepper tumbling and fluidization state by pulse air supply, thereby enhancing the heating and dehydration effect of the pepper stems and the bottom layer of peppers. The system uses solar energy as the main heat source, is energy-saving and environmentally friendly, and has modularized design for easy maintenance and operation. It is suitable for large-scale promotion and application in the pepper processing industry, and has good practicality and application prospect.

[0048] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A solar-powered industrial chili drying system, comprising a solar collector, an air duct, a fan, a box-type drying tunnel, a material tray, and a track, wherein the track is located at the bottom of the box-type drying tunnel, the material tray is placed on the track, the solar collector absorbs solar radiation and heats the air, and the fan drives the hot air through the air duct into the interior of the box-type drying tunnel, characterized in that: The drying chamber has an inverted isosceles trapezoidal structure. The bottom edge of the drying chamber and the material tray are provided with multiple hot air passages, and the air duct is connected to the hot air passages.

2. The solar-powered industrial chili drying system as described in claim 1, characterized in that: The angle between the inner walls of the two sides of the inverted isosceles trapezoid and the lower base is 45°. o Up to 75 o .

3. The solar-powered industrial chili drying system as described in claim 1, characterized in that: The tray is slidably mounted on the track.

4. The solar-powered industrial chili drying system as described in claim 1, characterized in that: The material of the tray is 304 stainless steel.

5. The solar-powered industrial chili drying system as described in claim 1, characterized in that: The oven cavity has a multi-layer composite structure, which includes an outer shell layer, an insulation layer and an inner liner layer from the outside to the inside. The outer shell layer is made of galvanized steel plate, the insulation layer is made of polyurethane foam, and the inner liner layer is made of 304 stainless steel.

6. The solar-powered industrial chili drying system as described in claim 1, characterized in that: The top of the drying tunnel is equipped with a dehumidification hole.

7. The solar-powered industrial chili drying system as described in claim 1, characterized in that: The hot air passage is rectangular in shape, with the long side of the rectangle along the moving direction of the material tray.

8. The solar-powered industrial chili drying system as described in claim 7, characterized in that: The width of the rectangle is less than the width of the chili pepper, and the length of the rectangle is greater than the length of the chili pepper.

9. The solar-powered industrial chili drying system as described in claim 1, characterized in that: The surface of the tray is provided with an array of spikes.

10. The solar-powered industrial chili drying system as described in any one of claims 1-9, characterized in that: The inverted isosceles trapezoid has multiple parallel protrusions extending along the inclined plane on its inner walls on both sides.

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