Application of Color Sorter in Fine Rice Processing

This article discusses the key points that rice factories should pay attention to in the selection, installation, management, and operation of color sorting machines in precision rice processing, in order to maximize the economic benefits of color sorting machines.

Application

The color sorter is a high-tech product that integrates light, machinery, electricity, and gas. It adopts a new digital technology design, advanced industrial computer management, and realizes the digitization of the system; Most of the color selection machines produced now use double-sided color selection, secondary selection function, high-resolution plasma screen display, which can achieve various ideal color selection accuracy adjustments.

The application of color sorter in rice processing requires research and discussion on equipment selection, process combination design, and equipment management in order to achieve the best process technology indicators, achieve the best process effect, and obtain ideal economic returns.

Equipment selection

1.1 Processing capacity. Production is the first consideration when choosing a color sorter. The output of a general color sorter is related to the quality of the raw materials (such as the type and quantity of color particles), the number of channels, the quality standards of the finished products, the performance of the equipment (the level of technological advancement), and so on. 

In order to match the production process before and after, color sorting machines are generally marked with a production range, namely a maximum flow rate and a minimum flow rate. At present, the grain market is open, and the quality of raw grains varies. In order to meet the processing needs of different grades of raw grains, it is advisable to choose the side closer to the rated flow rate. Because the quality standards for finished products have been established, it is necessary to adjust the flow rate and other aspects according to the different quality of raw grains in order to meet the requirements. 

1.2 Technical indicators. Technical indicators determine the level of equipment advancement and economic return rate. 

Color selection accuracy (the ratio of the weight of the selected substance containing heterochromatic particles after color selection to the weight of the original material before selection, expressed as a percentage), and color selection rejection ratio (the ratio of the weight of heterochromatic particles removed after color selection to the weight of the original material) are two important indicators that are generally measured under the condition of heterochromatic particle content below 2% and rated flow rate, and are related to the type, color, and density of heterochromatic particles. 

The heterochromatic grains in white rice mainly include yellow grains, rice grains, sand and gravel, moldy grains, heterogeneous grains, and immature grains. For materials with lighter colors or local color variations, old-fashioned or low-quality color sorting machines may not be sensitive enough. The new generation of color sorting machines has achieved ideal results through technological upgrades. 

1.3 Equipment failure rate. The failure rate of equipment is an important indicator for measuring the quality of equipment. This indicator is high, indicating unstable performance and quality, inadequate technology, which will affect the normal production of future use and should be taken seriously. 

1.4 After sales service. After sales service is an important aspect of choosing a color sorter. Some manufacturers purchase pure imported equipment, but encounter problems such as delayed maintenance, inadequate supply of spare parts, prices several times higher than domestic ones, and lack of cooperation in technical upgrades, which seriously affect normal production.

After sales service depends on service commitments and fulfillment, faults that cannot be eliminated by rice factory employees, how many hours the color sorter manufacturer takes to arrive, supply and price of spare parts, technical upgrades, training, and other issues. 

1.5 Price. After comparing the output, technical indicators, performance, after-sales service, etc. of the equipment, the focus should be on the prices of the products, in order to achieve maximum benefits with minimal investment. Especially for private enterprises in the early stages of development, the investment in color selection machines is not a small amount and needs to be demonstrated. 

On site management of equipment

The color sorter is a high-tech equipment, so the operators and managers of the equipment must have a high school education or above and a strong sense of responsibility. Strict business training must be conducted before taking up the post, and only those who pass the qualification can be employed. 

2.1 Dedicated on-site management. The color selection machine should be operated by a dedicated person and relatively stable. Technical indicators should be linked to the economic responsibility system, and responsibilities for equipment operation, maintenance, inspection, regular inspection, and shift handover should be clearly defined. The work content and equipment responsibilities should be clarified. Specific requirements should be set for the time, location, method, and recording of equipment operators' inspections, equipment lubrication, equipment status monitoring, and hygiene area specific recording requirements. Quantitative assessments should be conducted on the completion of equipment status and indicators by equipment operators and management personnel, such as equipment integrity rate, failure shutdown rate, etc. 

2.2 On site standardized management. According to the Regulations on Equipment Management of Industrial Transportation Enterprises issued by the State Council and combined with the characteristics of equipment, establish and improve various rules and regulations to systematically regulate the behavior of on-site management personnel. Require operators to:

a、 To understand the equipment, one should have four understandings, three skills, and three qualities, namely understanding the principles, structure, purpose, and performance; Can operate, troubleshoot, and maintain; Manage, use, and repair well. 

b、 Maintain the site three times regularly, namely, inspect, clean, and maintain the equipment regularly and truthfully, and follow the operation methods of cleaning, lubricating, tightening, and adjusting equipment maintenance in a standardized manner. 

c、 On site inspection involves listening, touching, smelling, comparing, and observing inspection methods. During the inspection, it is necessary to tighten the wrench, use a cloth to wipe, and listen with a stethoscope. 

d、 The three prohibitions of equipment operation are: no overpressure, no overspeed, no overload, and the five prohibitions of no leakage, namely no material leakage, no dust leakage, no air leakage, no oil leakage, and no water leakage. 

e、 The site should be flat, clean, visible, non-existent, and not lacking, that is, the site should be flat, the doors, windows, and glass should be clean, and the surrounding walls should be clean; See the bottom of the ditch, see the light on the axis, and see the true color of the equipment; No garbage, no miscellaneous waste, no idle equipment, no shortage of door and window glass, no shortage of lighting equipment, and no shortage of trench cover plates.

Process requirements and design

3.4.1 Strong light (such as lighting equipment) or sunlight should not be directly directed onto the color sorter, otherwise it will reduce the ability of the photoelectric system to capture signals, making it difficult to distinguish information such as color particles, thereby reducing color selection accuracy, increasing the output ratio, and reducing the effectiveness of color selection. 

3.4.2 There should be no strong electromagnetic interference around the color sorter, such as high-frequency emission, welding, etc., otherwise it may affect the normal operation of the color sorter. 

3.4.3 The color sorter should not be installed in places with high or strong vibration, otherwise it may affect the color sorter effect and damage the color sorter. 

3.4.4 The color sorter should not be installed in places with low temperature, high temperature, humidity, and high dust. The operation room of the color sorter should be isolated from other equipment in the rice mill and ensure good ventilation. When the temperature is below 5 ℃ or above 35 ℃, air conditioning should be installed. 

3.4.5 The ground should be level and there is no need to embed anchor bolts. 

In the rice entering the color sorter, there should be no stones, metals, or other substances. This requires the installation of reasonable cylindrical initial cleaning screens, flat rotary screens, stone removal machines, dust collection air nets, self balancing vibrating screens, and magnetic separators in the initial cleaning section to remove various impurities as much as possible, reduce the content of color particles, reduce the working pressure of the color sorter, play the initial cleaning function, and improve the efficiency of color selection. 

Before selecting the 3.6 beige color, it should be polished first. The polished rice is white and shiny, with a good appearance and no bran powder or other powdery substances. If rice contains a lot of powdery substances, high moisture content, and has a suitable temperature for a long time, it is prone to clumping in the channel, which affects the flow of rice grains. At the same time, the high concentration of dust in the sorting room will affect the recognition ability of the electric eye, reduce the accuracy of color selection, and shorten the service life of the color selection machine. 

Before selecting the 3.7 beige color, it is necessary to grade the white rice. After processes such as hulling, milling, polishing, rough separation, and mechanical transportation, some of the grains have become fragmented and discolored, mainly immature grains, moldy grains, yellow grains, etc. These grains have low tensile and compressive strength, higher crushing rates than normal, and a high proportion of medium and small crushing. By grading, the workload of the color sorter can be greatly reduced. 

3.8 Compressor. The air compressor should be oil-free and waterless, and should also be equipped with filters and dryers. All gas pipelines should be free of pollution and connected with rubber pipes, galvanized pipes, or higher grade pipelines. The air compressor should be placed in a separate house near the color sorter, preferably not more than 15m away, to reduce pressure loss and noise. When installing an air compressor, attention should also be paid to the impact of the surrounding environment on it. 

The gas supply system should supply clean, dry, and stable compressed air to the jet drive system. Otherwise, it will damage the gas supply system equipment and the nozzle, causing the nozzle to spray continuously or unable to spray, resulting in the failure of the jet system and ultimately the color sorter not working properly. After the air compressor is shut down, the waste liquid should be immediately emptied. 

3.9 Feeding hopper. The feeding hopper plays a buffering and regulating role by storing incoming materials, ensuring uniform feeding of the color sorter without being affected by changes in the previous flow rate. The feeding hopper of a general rice factory can be designed and installed according to the actual situation of the workshop, and it is generally recommended to ensure that the color sorter can work continuously for 30 minutes. 

The feeding hopper can be supported by brackets or directly suspended on the floor slab, and cannot be carried by the color sorting machine. The lower end of the feeding hopper should enter the feeding port of the machine by at least 50mm, and sufficient size should be ensured, otherwise it will affect the uniformity of the feeding. When designing the feeding hopper, the need for secondary sorting should be taken into account. 

The feeding hopper should have the correct feeding method, and the feeding pipe should be placed in the top center position of the feeding hopper. Rice should first fall to the sorting tray before falling into the feeding hopper, otherwise automatic grading may occur due to the difference in specific gravity between some discolored particles and rice particles, resulting in a higher content of discolored particles in local areas. The feeding pipe entering the hopper cannot be biased to one side, and it is necessary to ensure that the content of different colored particles is basically consistent throughout the cross-section of the hopper, without affecting the normal operation of color selection. 

A few points to note

4.1 When operating the keyboard, lightly touch the keys and avoid hitting them with heavy or sharp objects. 

4.2 It is not allowed to use hard objects to wipe the channel, otherwise it will damage the surface of the channel and affect the color selection effect. 

When cleaning the channel sorting room, hopper, etc. with a gas gun, do not blow the gas gun towards the nozzle direction. 

4.4 The operation of the color sorter should strictly follow the operating procedures, and only after confirming that the preparation work has been done can it be turned on; Shutdown should also follow the shutdown sequence and cannot be done arbitrarily. 

4.5 To prevent interference and ensure personnel safety, supporting equipment and hosts should be well grounded with a grounding resistance of less than 10 Ω. 

Reference: Zhou Qingjun's Discussion on the Process and Equipment Management of Modern Rice Mills