Equipment and solutions optimized for rice processing

Rice is possibly the grain that has been cultivated the longest and most extensively, occupying approximately 9% of the total arable land and is the second most important cereal for human nutrition, after wheat. It is currently the food base for two thirds of the world’s population.

The milling in rice differs completely from that of wheat. Wheat is ground into flour, while rice milling involves husking, removing bran, and finally separating broken and damaged grains.

The rice of the field is the whole, known worldwide as “paddy” or paddy rice; It contains an inedible, fibrous outer layer called the husk (glumes and glumes). When the skin is removed, but the pericarp (the bran) and the germ are preserved, brown rice is obtained, which after polishing it becomes white rice. Rice is produced only for human consumption as food.

The most important quality criteria for rice are milling efficiency, the appearance of the raw grain, the cooking behavior, and the texture and aroma of the cooked grain. Milling yield is a measure of the proportion of intact whole grains and reflects variety, growing, harvesting, and subsequent handling conditions. Biometrics (dimensions and shape of the grain), the color and the characteristics of the pearl (dark areas of the grain, without crystallinity) participate in the appearance of the raw grain.

The rice is transported to the rice mill plant, then it is emptied into hoppers, which by means of elevators and conveyors are taken to the wet rice reception silo, and from there they are distributed to the different drying towers, according to the size of the modern rice mill plant. In these towers, the rice is subjected to a process of drying by air or heat to reduce the humidity of the grain, to the optimal parameters for its storage (12.5% ​​- 13.5%).

During storage, the rice is attacked by insects, rodents and fungi, which will affect the product in different climatic conditions. The reduction can influence the quantity; hence corrective measures are adopted to prevent these agents from being fought quickly and effectively.

The rice, after being dried and stored, goes to the rice milling where it will be processed for the consumption of the population.

Design and layout of mill plants

As a first step, the dry paddy rice is passed to a cleaning machine, which will give it a final purification process. Then they are transferred to a rubber roller where the grain is separated from the shell by 95%, the expulsion is covered and the product is peeled with part of it. These peeled grains are sent to the densimetric table where the rice is separated. The peeled grain continues the process to the rice polishers, where the surface layer or bran is removed; This method is called grit polishing. Rice bran or “powder” is used as animal feed; the polished rice is transported to the classifiers where the whole grain is separated and the broken grain is classified.

Once the rice is processed, it is transferred to the packer to be packed in plastic bags or bags.