A method for processing high-quality rice

Abstract

This invention discloses a high-quality rice processing method, belonging to the field of rice processing technology, including the following steps: screening → soaking → dehulling → milling → cooling → primary polishing → secondary polishing → color sorting → drying → sieving and packaging; The cold treatment combined with soaking at a constant water temperature of 40-50℃ softens the rice husk and helps reduce the adhesion between the husk and rice grains, lowering the biomechanical force at the junction of the husk and the kernel; the processing method provided in this application achieves a dehulling rate of 98.7%, and the broken rice rate during processing is 1.4-1.8%, which improves the integrity rate of rice, increases the rice yield, and enhances the purity of the rice. This effectively solves the problems in existing rice processing methods, such as poor dehulling, easily resulting in broken rice grains that are prone to breakage during subsequent processing, compromising the quality of the finished rice and causing a decrease in the yield of refined rice.

Description

Technical Field

[0001] This invention relates to the field of rice processing technology, specifically a method for processing high-quality rice. Background Technology

[0002] Rice is one of my country's main food crops. my country has abundant rice genetic resources. With the continuous improvement of rice planting technology, the yield per unit area of ​​rice in my country has achieved a qualitative leap. When processing rice into rice, the process generally involves removing impurities, hulling, separating the paddy from the coarse grain, secondary hulling, coarse milling, fine milling, white rice grading, color sorting, polishing, and packaging. Due to the different operating conditions of each factory, the quality of rice produced by the existing rice processing methods varies.

[0003] In the existing hulling process, the high adhesion between the husk and the rice grain results in a hulling rate of only 3 / 5. Unhulled rice is returned to the machine for hulling again, making the rice grains prone to breakage during the hulling process. This leads to a broken rice rate of up to 25% during processing, thus reducing the rice yield. In order to improve the hulling effect, existing rice producers soak the rice before hulling to soften the husk and drain the water before placing it in the hulling machine. This achieves a hulling rate of 5 / 6, but the rice grains are still prone to breakage during processing, with a broken rice rate of up to 18%. This cannot guarantee the quality of the finished rice, resulting in a decrease in the yield of refined rice and affecting sales.

[0004] Chinese patent CN110152765B discloses a rice processing method, which includes steps such as coarse selection, dehulling, separation, polishing, grading, and storage. This rice processing method directly processes the rice harvested from the field, without drying it, and soaks it in sodium carbonate. This not only effectively removes the husk but also greatly reduces costs. The natural rice grains, unaffected by any external forces, possess natural toughness, minimizing the chance of breakage during soaking and centrifugal drying. Chinese patent CN111632645B discloses a rice processing method, including initial screening, drying, dehulling, whitening, screening, drying, surface softening, cooling, crushing, drying, screening, and packaging. This invention further reduces the moisture content of the screened white rice by high-temperature drying, increasing the rice grain's brittleness and facilitating the absorption of high-temperature steam. After being sprayed with high-temperature steam, the central part of the rice grain retains a low moisture content to maintain its brittleness.

[0005] However, existing rice processing methods are ineffective at removing the husks, resulting in rice grains cracking and easily breaking during subsequent processing. This makes it difficult to guarantee the quality of the finished rice and leads to a decrease in the yield of refined rice. Therefore, this application aims to provide a high-quality rice processing method that produces high-quality finished rice and reduces the cracking and breakage of rice grains during processing. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems in existing rice processing methods, such as poor rice hulling, easy breakage of rice grains, and easy crushing of rice grains during subsequent processing, which cannot guarantee the quality of finished rice and leads to a decrease in the yield of refined rice. This invention provides a high-quality rice processing method that produces high-quality finished rice and reduces the breakage of rice grains during processing.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for processing high-quality rice, comprising the following steps: screening → soaking → dehulling → rice milling → rice cooling → primary polishing → secondary polishing → color sorting → drying → sieving and packaging; Screening: The rice is fed into a vibrating screen with magnetic separation function to remove impurities, gravel and metal; Soaking: The screened rice is first cold-treated by air at 2-4℃ for 8-12 minutes. Then, the cold-treated rice is soaked in a soaking device with a constant water temperature of 40-50℃ for 15-20 minutes and then drained and dried. Hulling: The drained and dried rice is fed into a hulling machine for hulling. Rice milling: The hulled brown rice is milled through a 3- or 4-pass horizontal sand roller rice milling machine to obtain raw rice; Cooling rice: Place the milled rice on a cooling device and let it cool for 3-5 minutes; First-stage polishing: The cooled rice is sent to a polishing machine for light polishing. Secondary polishing: The rice after primary polishing is sent to a polishing machine for secondary polishing; Color sorting: The rice after secondary polishing is sent into a color sorter for color sorting. Drying: The color-sorted rice is sent into a dryer for drying. Sorting and Packaging: The dried rice is sent to a grading sieve for sorting and then packaged according to different grades.

[0008] Furthermore, the soaking device includes a soaking tank, which contains a soaking conveyor belt for soaking and transporting rice. The discharge end of the conveyor belt is positioned at one end of the soaking tank via a drain rack. The other end of the soaking tank is equipped with a feeding device, which consists of a cylinder and a spiral feeding belt vertically positioned within the cylinder. The cylinder has multiple cold air ports corresponding to the spiral feeding belt. The soaking tank also has a vortex tube, which comprises a tube body and a hot / cold separation assembly positioned within the tube body. The tube body has a vortex air inlet, which is connected to an air compressor via an air inlet pipe. Both ends of the vortex tube have hot air outlets and cold air outlets, respectively. The cold air outlet is connected to an air supply port via a cold air delivery pipe. The air supply port is fixedly connected to the feeding device. The hot air outlet is connected to a first guide pipe and a second guide pipe via a hot air delivery pipe. The hot air transfer pipe is equipped with an airflow control valve for controlling the airflow entering the first and second guide pipes.

[0009] Furthermore, the cylinder is provided with 2-5 cold air ports at equal intervals and in an alternating manner corresponding to the spiral feeding belt, and the cold air ports are inclined downwards at an angle of 45-60° with the cylinder.

[0010] Furthermore, the air inlet is positioned at a 20-40° angle to the feeding device and the cold air inlet, and the length of the air inlet extending into the cylinder is less than the length of the cold air inlet extending into the cylinder.

[0011] Furthermore, the first guide pipe is placed on the draining rack, and multiple air outlets are opened at equal intervals corresponding to the soaking conveyor belt. The draining rack is also equipped with a flow-gathering plate, which gathers and guides the hot air flowing out of the first guide pipe, so that it acts on the rice on the soaking conveyor belt.

[0012] Furthermore, the second guide pipe is disposed in the soaking tank and positioned below the soaking conveyor belt. The second guide pipe has exhaust ports at equal intervals on one side relative to the soaking conveyor belt, and the exhaust ports are equipped with one-way exhaust valves for unidirectional flow of hot gas.

[0013] Furthermore, the cooling device includes a housing and a spiral cooling conveyor belt disposed within the housing. The spiral cooling conveyor belt is provided with ventilation holes. The lower end of the housing is provided with an air supply end for blowing air onto the spiral cooling conveyor belt, and the upper end of the housing is provided with an air outlet end for drawing air from the spiral cooling conveyor belt.

[0014] Furthermore, the air intake volume at the air inlet is greater than the air outlet volume at the air outlet, and the air intake temperature at the air inlet is 14-17℃.

[0015] Furthermore, in the drying step, the dryer dries the color-sorted rice at a temperature of 38-43℃ until the rice moisture content is 14.5-15.5%.

[0016] The present invention provides a high-quality rice processing method, which has the following beneficial effects: This application utilizes cold treatment combined with soaking in a constant water temperature of 40-50℃ to soften the rice husk while reducing adhesion between the husk and rice grains, and lowering the biomechanical force at the junction of the husk and the pericarp. The processing method provided in this application achieves a dehulling rate of 98.7%, with a broken rice rate of 1.4-1.8% during processing. This improves the integrity of the rice, increases the rice yield and purity, and effectively solves the problems of poor dehulling in existing rice processing methods, which easily result in rice grains breaking and becoming easily brittle during subsequent processing, thus failing to guarantee the quality of the finished rice and causing a decrease in the yield of refined rice. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the soaking device structure for the high-quality rice processing method of the present invention.

[0018] Figure 2 This is a schematic diagram of the cooling device structure for the high-quality rice processing method of the present invention.

[0019] In the diagram, 1. Soaking tank; 2. Soaking conveyor belt; 3. Draining rack; 4. Cylinder; 5. Spiral feeder belt; 6. Vortex tube; 7. Cold air conveying pipe; 8. Hot air conveying pipe; 9. Air inlet; 10. First guide pipe; 11. Second guide pipe; 12. Airflow control valve; 13. Cold air outlet; 14. Condensing plate; 15. Exhaust port; 16. Shell; 17. Spiral spreading conveyor belt; 18. Air supply end; 19. Air outlet. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. The described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] Example 1 The present invention provides a high-quality rice processing method, comprising the following steps: screening → soaking → dehulling → milling → cooling → primary polishing → secondary polishing → color sorting → drying → sieving and packaging; Screening: The rice is fed into a vibrating screen with magnetic separation function to remove impurities, gravel and metal. The vibrating screen described in this application combines the advantages of existing vibrating screens and planar rotary screens. Its screen holes are configured with an upper layer of Φ12-14mm and a lower layer of Φ1.8-2.2mm. Large impurities (such as rice straw, rope ends, etc.) are removed through the upper layer screen holes, and small impurities (such as stones, iron filings, etc.) are removed through the lower layer screen holes.

[0022] Soaking: The screened rice is first cold-treated by air at 2-4℃ for 8-12 minutes. Then, the cold-treated rice is soaked in a soaking device with a constant water temperature of 40-50℃ for 15-20 minutes and then drained and dried.

[0023] Hulling: The drained and dried rice is fed into a hulling machine for hulling. The hulling machine uses two rubber rollers that rotate at different speeds in opposite directions to apply pressure and friction to both sides of the rice, causing the husk to break and separate from the brown rice. Through production tests and comparisons, it was found that when the distance between the two rollers is controlled at 0.75-0.77mm, the linear speed of the fast roller should be controlled at 15-16.5m / s, the linear speed of the slow roller should be controlled at 12.5-14m / s, and the difference in linear speed is controlled at 2.8-3.2m / s, the rubber consumption can be reduced while reducing the occurrence of brown rice breakage and fragmentation.

[0024] Rice milling: The hulled brown rice is milled through a 3- or 4-pass horizontal sand roller rice milling machine to obtain raw rice. This application uses an MNMS18×2 / MNMS25×2 horizontal double roller air jet rice milling machine to perform a multi-machine light milling process on the hulled brown rice, which can whiten the rice grains while maintaining their original shape.

[0025] Cooling the rice: Place the milled rice on a cooling device and let it cool for 3-5 minutes to bring the temperature of the rice close to room temperature. This can effectively reduce the heat effect that could cause increased breakage during subsequent polishing.

[0026] First-stage polishing: After cooling, the initial rice is sent to a polishing machine for light polishing to remove bran powder and avoid the bran powder affecting the color sorter's performance.

[0027] Secondary polishing: The rice after primary polishing is sent to a polishing machine for secondary polishing, which can effectively gelatinize the starch on the surface of the rice grains, forming a bright gelatinous film and improving the polishing effect.

[0028] Color sorting: The rice after secondary polishing is fed into a color sorter for color sorting. The material is evenly fed into the feed channel of the polisher by a vibrating feeder and enters the color sorting area at a certain speed, passing between the sensor and the background plate. The photoelectric sensor observes the rice by observing the different light refracted by the background plate under the illumination of the fluorescent lamp. The sensor generates a corresponding voltage signal based on the color difference, which is amplified and transmitted to the CPU central processing unit. The CPU analyzes and distinguishes the rice and generates an output electrical signal, which is amplified by the drive circuit board. This amplifies the signal and drives the jet solenoid valve to blow out the discolored or chalky grains from the good rice into the waste chamber of the receiving hopper. The normal selected material continues to fall into the finished product chamber of the receiving hopper, thereby achieving the purpose of separating discolored grains. Different parameters can also be set according to the material quality and color requirements to improve the appearance quality of the polished rice.

[0029] Drying: The color-sorted rice is sent to a dryer for drying. According to Zheng Xianzhe's research on the relationship between the quality and taste value of dried rice, a mathematical model of the main components of rice and taste value was derived through regression analysis. When the drying temperature exceeds 45℃, the starch inside the rice is arranged in a disordered manner, and the starch particles and endosperm cell walls are difficult to decompose. With the increase of drying temperature and the increase of internal fatty acid content during storage, the aging degree of rice is deepened, and starch gelatinization is inhibited. Through comparative experiments, it was found that the drying temperature of the color-sorted rice in this application is 38-43℃. When the moisture content of the rice is dried to 14.5-15.5%, the taste quality of the rice produced by the processing method of this application is excellent, according to the sensory evaluation method of GB / T15682-2008 Grain and Oil Inspection: Rice and Rice Cooking and Eating Quality.

[0030] Sorting and Packaging: The dried rice is sent to a grading sieve for sorting and then packaged according to different grades.

[0031] This application processes 1 ton of paddy rice according to the above-mentioned processing method, resulting in rice with plump grains, a bright and lustrous color, clean and free of impurities, and a special aroma. Before hulling, the paddy rice is first cold-treated with cold air, and then soaked in a soaking device with a constant water temperature of 40-50℃ for 15-20 minutes, followed by draining and drying. Cold treatment helps reduce the adhesion between the husk and the rice grain, and reduces the biomechanical force at the junction of the husk and the kernel. After further processing... Soaking the rice at a constant water temperature of 40-50℃ for 15-20 minutes allows for a rapid transition from low to high temperature, further disrupting the cell structure of the husk and reducing adhesion between the husk and the rice grains. According to the processing method provided in this application, the dehulling rate is 98.7%, and the broken rice rate during processing is 1.4-1.8%. This improves the integrity of the rice, increases the rice yield and purity, and effectively reduces the risk of rice grains bursting during processing and becoming easily broken in subsequent processing steps.

[0032] Control Group 1 Based on the above embodiments, the difference between this control group and Embodiment 1 is that, in the soaking step, the screened rice is first subjected to frost-free cold air at -18 to 0°C for 8-12 minutes, and then the cold-treated rice is soaked in a soaking device with a constant water temperature of 40-50°C for 15-20 minutes before being drained and dried. Comparative experiments show that the rice treated in Control Group 1 has a lower integrity rate after processing compared to the rice treated in Embodiment 1. The broken rice rate in Control Group 1 during processing is 2.6-3.0%, and the dehulling rate is 93.4%. While freezing the rice in Control Group 1 can break the adhesion between the husk and the grain, it may alter the internal structure of the rice, making it more prone to breakage after soaking, thus reducing its processing quality.

[0033] Control Group 2 Based on the above embodiments, the difference between this control group and Embodiment 1 is that, in the soaking step, the screened rice is first soaked in a soaking device at a constant water temperature of 40-50℃ for 15-20 minutes, and then drained and cold-treated with cold air at 2-4℃ for 8-12 minutes. Comparative experiments show that the rice treated in Control Group 2 has a lower integrity rate after processing compared to the rice treated in Embodiment 1. Control Group 1 has a broken rice rate of 2.3-2.5% during processing, and a dehulling rate of 89.5% during the dehulling process. In control group one, soaking the rice in hot water first softens the husk, but it does little to break the bond between the husk and the rice grain, resulting in a low hulling rate. In control group two, after draining, the rice is treated with cold air. The cold air can remove some of the moisture from the drained rice, but most of the moisture remains in the husk in a short time. Excessive moisture in the rice will affect the subsequent hulling effect and increase the breakage rate. If the cold air volume and cold treatment time are increased as in control group two to meet the requirements of subsequent hulling, it will increase the energy consumption of cold treatment and increase production costs.

[0034] Control Group 3 Based on the above embodiments, the difference between this control group and Embodiment 1 is that, in the soaking step, the screened rice is first subjected to cold air at 2-4°C for 8-12 minutes, and then the cold-treated rice is soaked in a soaking device with a constant water temperature of 18-25°C for 15-20 minutes before being drained and dried. According to comparative experiments, the rice treated in Control Group 3 has a lower integrity rate after processing compared to the rice treated in Embodiment 1. Control Group 1 has a broken rice rate of 2.1-2.4% during processing and a dehulling rate of 95.6% during dehulling. The cold treatment in Control Group 1 breaks the adhesion between the husk and the rice grain, and the soaking in a constant water temperature of 18-25°C softens the husk. However, the secondary damage to the adhesion between the husk and the rice grain is relatively small, thus reducing the integrity of the rice grain in subsequent processing.

[0035] In summary, the high-quality rice processing method provided in this application has a broken rice rate of 1.4-1.8% and a hulling rate of 98.7% during processing. Compared with existing processing methods, it has significant technical advantages. The processing method provided in this application can improve the integrity rate of rice, increase the rice yield and the purity of rice, and effectively solve the problems of rice grains breaking in the middle during processing and rice grains being easily broken in subsequent processing, which cannot guarantee the quality of finished rice and cause a decrease in the yield of refined rice.

[0036] Example 2 Based on the above embodiments, this embodiment aims to improve the quality of rice soaking by reducing the adhesion between the husk and the rice grains while minimizing the breakage rate of the rice grains during subsequent processing. Figure 1As shown, the soaking device described in this application includes a soaking tank 1 made of stainless steel. The soaking tank 1 contains a soaking conveyor belt 2 for transporting soaked rice. Drainage mesh holes are evenly spaced on the soaking conveyor belt 2. The discharge end of the soaking conveyor belt 2 is placed at one end of the soaking tank 1 via a drain rack 3. A liquid collection tank is located at the lower end of the drain rack 3 and is connected to the soaking tank 1 via a pipeline. A feeding device is located at the other end of the soaking tank 1. The feeding device consists of a cylinder 4 and a spiral feeding belt 5 vertically disposed within the cylinder 4. A drive motor for driving the spiral feeding belt 5 is located at the upper end of the cylinder 4. A frequency converter is provided corresponding to the drive motor in the cylinder 4. The frequency converter parameters are set by the operating controller to reduce the speed of the spiral feeding belt 5 driven by the drive motor, i.e., the spiral feeding belt speed is 55m. In this application, the rice is cold-treated in the feeding device for 8-12 minutes at a temperature of 2-4°C. The cylinder 4 is provided with multiple cold air ports 13 corresponding to the spiral feeding belt 5. The cylinder 4 is provided with 2-5 cold air ports 13 at equal intervals and staggered with the spiral feeding belt 5, and the cold air ports 13 are inclined downwards at an angle of 45-60° with the cylinder 4. The cold air enters the cylinder 4 and rises when it encounters the hot air entering from the discharge end of the cylinder 4. During the continuous filling of cold air, the cold air sinks. The cold air can quickly fill the cylinder 4 through the entry of hot air from the discharge end of the cylinder 4, so that the rice on the spiral feeding belt 5 can fully contact the cold air. The cold treatment can help reduce the adhesion between the husk and the rice grain, reduce the biomechanical force at the junction of the husk and the core, and facilitate the softening effect of the rice after soaking in a constant water temperature of 40-50°C.

[0037] The soaking tank 1 is also equipped with a vortex tube 6, which includes a tube body and a hot and cold separation component disposed within the tube body. A vortex air inlet is provided on the tube body, and the vortex air inlet is connected to an air compressor via an air inlet pipe. Hot air outlet and cold air outlet are respectively provided at both ends of the vortex tube 6. This application provides a pressure control valve for controlling the airflow output of the hot air outlet and the cold air outlet. The cold air outlet is connected to an air supply port 9 via a cold air delivery pipe 7. The air inlet 9 is fixedly connected to the feeding device. The air inlet 9 passes through the feeding device and is set at an angle of 20-40° with the cold air inlet 13. The length of the air inlet 9 extending into the cylinder 4 is less than the length of the cold air inlet 13 extending into the cylinder 4. This may cause the airflow to form a vortex on the spiral feeding belt 5, increasing the residence time of the cold air in the cylinder 4 and increasing the effect of the cold air on the rice, so that it can fully contact the rice and improve the breaking of the adhesion between the rice husk and the rice grain, thereby facilitating the subsequent dehulling process.

[0038] The hot air outlet is connected to the first guide pipe 10 and the second guide pipe 11 via the hot air delivery pipe 8. The hot air transfer pipe is equipped with an airflow control valve 12 to control the airflow into the first guide pipe 10 and the second guide pipe 11. The first guide pipe 10 is placed on the drain rack 3, and has multiple air outlets spaced evenly across the soaking conveyor belt 2. The drain rack 3 is also equipped with a converging plate 14, which gathers and guides the hot air flowing out of the first guide pipe 10, directing it onto the rice on the soaking conveyor belt 2. This ensures the rice achieves an appropriate moisture gradient, thereby reducing the need for subsequent threshing. The second guide pipe 11 is located inside the soaking tank 1 and below the soaking conveyor belt 2. The second guide pipe 11 has exhaust ports 15 at equal intervals on one side relative to the soaking conveyor belt 2. The exhaust ports 15 are equipped with one-way exhaust valves for unidirectional flow of hot air. By setting the second guide pipe 11, the water in the soaking tank 1 can be stirred, so that the water in the soaking tank 1 is in a floating state and acts on the rice, thereby increasing the impact of the water on the rice, which can improve the softening of the rice husk and further reduce the adhesion between the rice husk and the rice grain.

[0039] Before operation, this application sets the parameters of the soaking conveyor belt 2, the spiral feeding belt 5, the vortex tube 6, and the airflow control valve 12 via the operation controller. Simultaneously, the paddy rice is conveyed to the feeding device for cold treatment via the conveyor belt, while the vortex tube 6 operates. After cold treatment, the paddy rice enters the soaking tank 1 through the discharge end of the feeding device. Hot air discharged through the second guide pipe 11 impacts the water in the soaking tank 1, causing the water to be in a floating state and acting on the paddy rice. The speed ratio of the soaking conveyor belt 2 to the spiral feeding belt 5 is 1.5:1, ensuring that the paddy rice entering the soaking tank 1 from the feeding device has the same soaking time, and that subsequently entering paddy rice does not mix with previously soaked paddy rice. As the soaking conveyor belt 2 moves, the soaked paddy rice is carried out of the soaking tank 1 and moves towards the drain rack 3, controlled by the airflow control valve 12. Valve 12 allows hot air to enter the first guide pipe 10. The hot air flowing out of the first guide pipe 10 is converged and guided to act on the rice on the soaking conveyor belt 2, so that the rice can reach the appropriate moisture gradient, thereby drying the rice. After soaking treatment according to this application, the dehulling rate of high-quality rice is 98.7%, and the overall broken rice rate in subsequent processing is reduced by more than 8%. The high-quality rice processing method provided by this application has significant technical effects compared with the processing methods in the prior art. According to the processing method provided by this application, the rice integrity rate can be improved, the rice yield and the purity of the rice can be improved, and the problem of rice grains breaking in the middle during processing and rice grains being easily broken in subsequent processing can be solved, which cannot guarantee the quality of finished rice and cause a decrease in the yield of refined rice.

[0040] Example 3 Based on the above embodiments, this embodiment aims to improve subsequent polishing brightness and reduce chipping, such as... Figure 2 As shown, the cooling device described in this application includes a housing 16 and a spiral cooling conveyor belt 17 disposed within the housing 16. The upper end of the housing 16 is equipped with a drive motor for driving the spiral cooling conveyor belt 17, and the drive motor is equipped with a matching frequency converter. The spiral cooling conveyor belt 17 has ventilation holes. The lower end of the housing 16 has an air supply end 18 for blowing air onto the spiral cooling conveyor belt 17, and the upper end of the housing 16 has an air outlet end 19 for drawing air from the spiral cooling conveyor belt 17. The air outlet end 19 shares a common opening with the feed end. The air intake at the air end is greater than the air output at the air outlet 19, and the air intake temperature at the air intake end is 14-17℃. This application, through the setting of the spreading and drying device, enables the rice temperature after several milling processes to quickly approach room temperature, reducing the heat effect that causes increased breakage during subsequent polishing. It can effectively prevent rice grains from bursting due to drastic changes in temperature and humidity, and reduce broken rice. Compared with traditional rice spreading and drying processes, the spreading and drying device provided by this application improves the quality of the finished rice by 5%, making the surface of the rice grains after subsequent polishing smoother and improving the quality of the rice.

[0041] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0042] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for processing high-quality rice, characterized in that, Includes the following steps: Screening → Soaking → Dehulling → Rice Milling → Rice Cooling → First-stage Polishing → Second-stage Polishing → Color Sorting → Drying → Sorting and Packaging; Screening: The rice is fed into a vibrating screen with magnetic separation function to remove impurities, gravel and metal; Soaking: The screened rice is first cold-treated by air at 2-4℃ for 8-12 minutes. Then, the cold-treated rice is soaked in a soaking device with a constant water temperature of 40-50℃ for 15-20 minutes and then drained and dried. Hulling: The drained and dried rice is fed into a hulling machine for hulling. Rice milling: The hulled brown rice is milled through a 3- or 4-pass horizontal sand roller rice milling machine to obtain raw rice; Cooling rice: Place the milled rice on a cooling device and let it cool for 3-5 minutes; First-stage polishing: The cooled rice is sent to a polishing machine for light polishing. Secondary polishing: The rice after primary polishing is sent to a polishing machine for secondary polishing; Color sorting: The rice after secondary polishing is sent into a color sorter for color sorting. Drying: The color-sorted rice is sent into a dryer for drying. Sorting and Packaging: The dried rice is sent into a grading sieve for grading and sorting, and then packaged according to different grades. The soaking device includes a soaking tank (1), which is equipped with a soaking conveyor belt (2) for soaking and transporting rice. The discharge end of the conveyor belt is placed at one end of the soaking tank (1) via a drain rack (3). The other end of the soaking tank (1) is equipped with a feeding device, which consists of a cylinder (4) and a spiral feeding belt (5) vertically arranged inside the cylinder (4). The cylinder (4) is equipped with multiple cold air ports (13) corresponding to the spiral feeding belt (5). The soaking tank (1) is also equipped with a vortex tube (6), which includes a tube body and a hot and cold separation component arranged inside the tube body. The tube body is provided with a vortex air inlet hole, which is connected to the air compressor through an air inlet pipe. The two ends of the vortex tube (6) are respectively provided with a hot air outlet and a cold air outlet. The cold air outlet is connected to an air delivery port (9) through a cold air delivery pipe (7). The air delivery port (9) is fixedly connected to the feeding device. The hot air outlet is connected to the first guide pipe (10) and the second guide pipe (11) through a hot air delivery pipe (8). The hot air delivery pipe (8) is provided with an airflow control valve (12) for controlling the airflow into the first guide pipe (10) and the second guide pipe (11). The first guide pipe (10) is placed on the drain rack (3), and multiple air outlets are opened at equal intervals corresponding to the soaking conveyor belt (2). The drain rack (3) is also provided with a flow-gathering plate (14) to gather and guide the hot air flowing out of the first guide pipe (10) so that it acts on the rice on the soaking conveyor belt (2). The second guide pipe (11) is located inside the soaking tank (1) and below the soaking conveyor belt (2). The second guide pipe (11) has exhaust ports (15) at equal intervals on one side relative to the soaking conveyor belt (2). The exhaust ports (15) are equipped with one-way exhaust valves for unidirectional flow of hot air.

2. The method for processing high-quality rice according to claim 1, characterized in that: The cylinder (4) is provided with 2-5 cold air ports (13) at equal intervals and staggered with the spiral feeding belt (5), and the cold air ports (13) are inclined downwards and set at an angle of 45-60° with the cylinder (4).

3. The method for processing high-quality rice according to claim 1, characterized in that: The air inlet (9) is set at an angle of 20-40° through the feeding device and the cold air inlet (13), and the length of the air inlet (9) extending into the cylinder (4) is less than the length of the cold air inlet (13) extending into the cylinder (4).

4. The method for processing high-quality rice according to claim 1, characterized in that: The cooling device includes a housing (16) and a spiral cooling conveyor belt (17) disposed inside the housing (16). The spiral cooling conveyor belt (17) is provided with ventilation holes. The lower end of the housing (16) is provided with an air supply end (18) for blowing air onto the spiral cooling conveyor belt (17), and the upper end of the housing (16) is provided with an air outlet end (19) for drawing air from the spiral cooling conveyor belt (17).

5. The method for processing high-quality rice according to claim 4, characterized in that: The air intake of the air supply end (18) is greater than the air output of the air outlet end (19), and the air intake temperature of the air supply end (18) is 14-17℃.

6. The method for processing high-quality rice according to claim 1, characterized in that: In the drying step, the dryer dries the color-sorted rice at a temperature of 38-43℃ until the rice moisture content is 14.5-15.5%.

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