There are three types of common rice hulling equipment: rubber roller hulling machine, sand plate hulling machine and centrifugal hulling machine. The operation and advantages and disadvantages of these three kinds of grain processing equipment are described in detail as follows.
Rubber roller husker: The main working parts are a pair of horizontal rubber rollers or plastic rollers that are bonded or covered with a rubber layer on a cast iron cylinder. The axes of the two rollers are located in the same horizontal plane or have a slight height difference, and rotate at different speeds. One of the rollers is fixed in position and the other roller can be moved so that the rolling distance between the two rollers can be adjusted. The difference between the line speeds of the two rollers is 2 to 3.2 m/s, and the sum of the line speeds should not exceed 30 m/s.
Sand hulling machine: With the help of two upper and lower round emery discs, the upper disc is fixed and the lower disc rotates, and the linear speed is 20-25 m/s. In the two sand trays, the rice is peeled off due to end pressure, rubbing and tearing. The advantage is that the brown rice has less bursting waist, the sand disc is more wear-resistant than the rubber roller, and the processing cost is lower; the disadvantage is that the shelling rate is lower and the broken rice is more. Compared with other miscellaneous grain processing equipment, its main working part is a ring-shaped emery disc bonded with a cast iron disc. The upper and lower discs are fixed, the lower disc rotates and can move up and down, according to the grain size of the rice. The size adjusts the gap (rolling distance) between the upper and lower sand discs.
Centrifugal husker: The main working part is the rotating slinger inside, and the outside is the fixed impact ring. When the rice enters the work area, it is accelerated by the throwing plate, and flies to the impact ring by centrifugal inertial force, and husks due to the impact. This machine has simple structure, convenient operation and management, low power consumption and low processing cost; but there are more broken rice and low rice output rate.