Currentlyrice polishing machineIt has been widely used in China, and how to reduce the increase in fragmentation and improve the integrity rate and surface brightness of rice grains is a more noteworthy issue. Here, Shuanghu Grain and Oil Machinery will further analyze the factors affecting the polishing effect of rice polishing machine for your reference.
With the rapid development of China's economy and the continuous improvement of people's living standards, rice deep processing technology has emerged in China. Therefore, engaged ingrain machineIndustry research, manufacturing units have aimed at the rice polishing machine market, has introduced foreign advanced rice polishing technology, researchDesignOut of all kinds of rice polishing machine.
1 Polishing characteristics
PolishingRollGenerally, iron rollers are used. The working principle of iron roller polishing is basically the same as that of iron roller grinding white. It is still rubbed white, which is completed by the joint action of five processes of collision, polishing pressure, tumbling, axial conveying and spraying water. However, polishing is not to grind away the whole bran layer, but to grind away the fine bran powder and the raised starch particles on the rough surface. Polishing and grinding white from the way of work to compare, there are the following differences:
① polishing pressure is low; ② polishing rice fluid density is small; ③ polishing rice leaves the iron roller faster; ④ unit output polishing movement area is large. 3 Analysis of factors affecting the polishing effect of rice polishing machine.
2 Rice making process
At present, the commonly used rice making process is: grinding white-rubbing white-spraying water polishing. First, grind and grind white and rough, and brown rice completes skin separation under the action of sand roller and sand edge cutting and grinding. The remaining bran layer and bran powder are removed by white grinding to improve the smoothness and color of the rice surface. After rubbing off the white rice, there is still a small part of bran powder left in the surface depression and there is a certain roughness, and then by spraying water polishing, more thoroughly grinding out bran powder, at the same time, in the polishing pressure and associated friction temperature under the action of the starch fine powder semi-gelatinization to form a smoother surface.
3.1 polishing pressure
The polishing pressure is established in the polishing chamber by the speed and collision force of the rice grains. There are many factors that affect the grinding pressure, but the polishing pressure can be adjusted and controlled by the pressure door at the outlet of the polishing chamber. The polishing pressure is large, the collision movement is violent, and the increase in fragmentation after polishing is more; the polishing pressure is small, the collision movement is moderate, and the increase in fragmentation after polishing is less. Therefore, a smaller polishing pressure should be used when polishing, but the polishing pressure is too small, which will affect the process effect. The general polishing pressure is about 400-700g/cm2.
The linear speed of the polishing roller is the main factor that determines the speed and collision force of the rice grains. If the linear speed is low, the speed of rice grains leaving the iron roller will be low, the collision movement will be relaxed, and the fragmentation will increase after polishing, but the speed is too low. When the rice grains are not rolled enough, the rice grains will be partially crushed too much, resulting in the phenomenon of over-grinding. Over-grinding will reduce the rice yield, and will also cause the rice grains to be partially crushed not enough and polished unevenly. The linear speed is high, the speed and collision force of rice grains are large, the chance of rice grains rolling is increased, and the polishing is more uniform, but when rice grains roll over. It will cause the rice grains to be crushed at both ends, and the broken rice will increase, which will also reduce the rice yield. Therefore, it is very important to choose a reasonable speed to obtain a suitable polishing roller linear speed to reduce the broken rice rate and improve the brightness of rice polishing. Generally, the linear speed of polishing roller should be 6-7 m/s.
3.3 the amount of water
During polishing, water is evenly sprayed on the rice in the polishing room according to a certain proportion to wet the surface of the rice, which is conducive to the separation of bran powder on the surface of the rice grains. At the same time, under the action of rubbing off polishing pressure and friction temperature generated in the polishing process, the rice surface is gelatinized to form a colloid layer, thus achieving the purpose of improving the brightness of the rice. However, excessive water quantity will cause abnormal flow of rice grains, resulting in excessive pressure in the polishing machine, thus increasing the fragmentation and even causing "stuffy car". Therefore, in the use of the polishing machine, the water quantity should be controlled first, and the water quantity is generally controlled at about 0.5%.
3.4 suction volume
Polishing air feeding forms include hollow shaft air spraying, strong pulling air suction, and combination of air spraying and air suction. For the axis of water-jet polishing machine should be used in the form of strong suction. Strong suction can make the water into the hollow shaft in the strong negative pressure quickly atomized, so as to improve the uniformity of the water. The use of strong pull suction can also increase the chance of rice grain turning and improve polishing accuracy. Promote the separation between rice grains and bran powder, which is conducive to the discharge of bran. Reduce the humidity and temperature of polished white rice to cool rice. However, if the suction * is too large, the polishing pressure of rice will be blocked and the broken rice will be increased. Therefore, according to the specific model to choose the appropriate suction air volume, in order to effectively reduce the increase in fragmentation, is conducive to the role of polishing.
3.5 rice flow
In the polishing process, the flow should be stable. If the flow rate is too small, the rice grains will have too many opportunities to turn in the polishing chamber, resulting in too much friction and impact force, thus resulting in over-grinding. Over-grinding will not only lose brightness on the surface of the rice grains, but also seriously affect the rice yield. If the flow rate is too large, the rice grains will not roll easily in the polishing chamber, making the rice grains less likely to contact the iron roller and rice sieve, and the processed rice rice sieve. Therefore, in the polishing process, it is necessary to properly control the flow according to the specific processing raw material varieties, specific practical operations, so that the rice grains can be properly flipped, impacted, squeezed, and rubbed in the polishing chamber to ensurepolishing machineThe processed rice achieves the process effect of complete rice grains and bright surface.