Knowledge

The main process of this kind of rice factory belongs to the rice milling and finished product finishing section of ordinary rice processing plants. Its process requirements are flexible, and it should be able to adapt to the deep processing requirements of various grades of white rice, while ensuring the use efficiency of the equipment. Through reasonable equipment layout, complex and flexible processes can be achieved.

1. Design principles of the process flow of the rice mill

Since the raw materials of this kind of rice factory are the finished products of other rice factories, their varieties are diverse, and there are far differences in the indicators such as impurity content, white grinding accuracy, crushing rate, different color particle content, easy processing degree, so the processing process of white rice as raw materials should be adapted to a wide range, and the design should be based on the processing of poor quality raw materials, while taking into account various grades of rice raw materials. To ensure the full use of equipment resources.

2. Process design of rice mill

The number of production lines should be selected according to the raw material situation and production capacity in the design of this type of rice factory, such as a rice factory in Shantou, using the design scheme of three production lines. The three production lines share rice distribution and color sorting, and can realize a variety of processes through different flow combinations. Its general process for cleaning, grinding white, polishing, grading, rice, color selection, packaging.

2.1 Cleaning Procedure

Raw materials generally contain very little impurity, but in order to ensure product purity, cleaning processes are necessary when processing general raw materials. The primary cleaning screen of this process mainly removes foreign matter mixed in the process of discharging, such as hemp rope, nylon rope, etc. The stone removal machine removes stones that are difficult to remove during rice processing. In order to ensure product quality and protect equipment, it is necessary to set up multiple magnetic separations throughout the process. Cleaning equipment requires large output and good effect.

In order to balance the flow rate and realize the process combination route, three raw material silos are set up after cleaning, one of which is equipped with related devices, and the process combination can be used for cooling rice after grinding white. The rice dispenser behind the raw material bin is mainly used for flow control, and can also be used for batching processing of medium materials.

2.2 White rolling process

In order to ensure the accuracy of the product, sand roller and iron roller are equipped with 1 track each. In view of the fact that the raw material has reached a certain precision, in order to reduce the crushing, according to different raw material conditions, it can be selected by different distribution silos whether the sand roll rice mill or the iron roll rice mill white or no white grinding process.

2.3 Polishing Process

In order to meet the aesthetic appearance of the product and extend the shelf life, 2 polishing steps are set. Before each polishing, the rice is cooled and crushed to improve the polishing effect and polishing stability. According to the requirements of the finished product, through the graded dipper, to achieve 1 polishing or 2 polishing.

2.4 Grading screening process

It is mainly used to remove the broken rice and rice bran in the product by the white rice grading screen and the length grading machine to improve the product grade and taste. In order to ensure the stability of product quality and control the broken rice effectively, the effective method is to use the first crushing and then mixing rice. The white rice grading screen adopts the screen frame structure of multi-layer screening surface combination and continuous screening under the screen, which has long screening route, good grading effect and small occupying space and maintenance space. The white rice grading screen can generally divide the material into four categories: impurity, whole rice, mixed rice and small broken rice. In the upper 2 layers of the selection of large aperture screen, such as 5 mesh ×5 mesh, used to remove the caked rice bran or clutter, in a certain process route to play a cleaning role. Using stainless steel braided screen, its effective screening area is large. The length classifier is strictly according to the length of the grading equipment, in the case of suitable configuration, the crushing effect is good, but the yield is small, so it can be used as the classification of the mixture after white rice grading. Because different varieties of rice differ greatly in length, multiple sets of screens and length classifier rollers should be selected.

2.5 Rice preparation process

In order to adjust varieties, reduce costs and control broken rice, it is necessary to match different rice and broken rice reasonably. Five large capacity rice mixing silos can ensure the variety and yield of rice mixing. When processing raw materials with a large content of different color rice, the output of the color sorter will decrease significantly, resulting in a bottleneck problem, which can be buffered by the rice distribution bin. In the case of better raw material quality, similar particle size and processing characteristics, it can be used to batch before processing to solve the problem of insufficient rice mixing bin. At present, there are two kinds of rice dispensers: gravity type and displacement type. In comparison, the gravity type rice distributor has no crushing, no accumulation of bran and simple structure, but it should do a good job of chain control.

2.6 Color selection process

The color selection process is to remove diseased spot particles, yellow head particles, immature particles, impurities and glass in the rice, so as to ensure that the rice powder is harmless, high purity and good appearance. Before the material enters the color separator, it passes through the suction separator to remove the rice bran, so that the color separator has a good working environment. The process color sorting machine itself is selected twice, which can effectively ensure the yield and quality. For the high content of different color rice, a color selection can not meet the requirements, after the 1# finished product warehouse can be returned to the color sorting machine for several times. At present, advanced color sorters can select both white and different color particles at the same time, which has high accuracy and small take-out ratio.

2.7 Packaging Process

Good packaging equipment and packaging materials can not only ensure product yield, improve product grade, but also extend the storage life of rice. The rice bran absorption before entering the finished product warehouse can ensure the quality of the product and extend the shelf life. The output of small packaging equipment is small, and multiple units can work at the same time to adapt to the processing production. Large packaging scales are mainly used when producing industrial rice or discharging materials.

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