Chapter 4 The correct use of rice hulling rubber rollers

　　1. The technological conditions of the rice husk:

　　The shelling process of cereal grains generally goes through three basic steps: squeezing, rubbing and tearing, and peeling. Among them, rubbing and tearing are the key to peeling. The size of rubbing and tearing depends on two important factors: one is the friction, and the friction The size depends on the pressure between the two rollers; the second is the length of the relative action time of the reverse friction force on the grain, and the length of this action time depends on the relative speed of the two rollers, that is, the line speed difference is related . It is not difficult to see that the pressure between the rollers and the line speed difference are important process parameters for rice hulling. The correct selection of it not only directly affects the hulling rate, but also affects the consumption of rubber rollers.

　　2. General principles for selecting process parameters:

　　The amount of rice milled by the rubber roller is actually a comprehensive reflection of the hulling rate and the amount of rubber consumption. The two interact and restrict each other. The so-called optimal process state refers to both a high hulling rate and a Lower glue consumption, this is the general principle for selecting various process parameters.

　　1. The choice of line speed difference: The line speed difference is too large, which can enhance the rubbing and tearing force and increase the peeling rate, but it also increases the abrasion and power consumption of the rubber roller. The line speed difference is too small, the hulling rate is low, the loss is low, the rice hulling is increased, and the total rice milling amount is not high. It can be seen that the line speed difference must take into account the two aspects of hulling rate and glue consumption, and one-sided pursuit of either All indicators are wrong. According to my many years of experience, it is better to choose the line speed difference of 2.4-3 m/s. When the line speed difference is less than two meters, the hulling rate will decrease significantly (the speed of the fast roller of the hulling machine is 1350 rpm, and the speed of the slow roller is 1150 revolutions per second; speed ratio is 1: 1.17), the rubber roller is constantly worn out when the hulling machine is working, and the linear speed difference is constantly shrinking, and the fast roller is even more important. In order to ensure a certain process effect, it must be maintained at a certain level. The line speed is poor. When the diameter of the fast roller is smaller than the diameter of the slow roller, the fast roller is replaced immediately. Generally, the diameter of fast rollers is 2-10mm larger than that of slow rollers. In actual work, the selection basis and factors of the linear speed difference are various, such as the variety of rice, the thickness and tightness of the husk, the moisture content and the climate conditions. Wait.

　　2. Selection of the pressure between the rolls: The pressure between the rolls is also one of the key process parameters for the size of the rubbing and tearing force. The pressure between the rolls is adjusted by the weight of the pressure on the roller hulling machine. In principle, it is easy to light but not heavy, and both sides are balanced. , It can increase the weight of the pressure as the rubber roller gradually wears; for the manual roller hulling machine, the width of the distance between the rollers should be equal to the thickness of the rice grains, generally 0.5 (indica)-0.8 (japonica) mm, should be kept diligent The principle of tightly feeding and parallel feeding.