Rice is generally over by rice polisher
Posté le 19/4/2018 à 04:47 - 0 Commentaires - poster un commentaire - LienThe term milling, in connection with the traditional method of processing or huller mills means removal of husk, bran and a part of endosperm in a single operation. This results in a mixture containing husk, bran and brown rice. In a huller mill, a metallic roller is used as a milling unit cleaned by a fixed or vibratory screen and/or fan. The huller mills are low capacity units handling 300-500 kg/h of paddy and in these, it is difficult to regulate the degree of polish and rice is generally over by rice polisher. Broken percentage is 20-30 %. Also husk gets powdered alongwith the bran and thus rendering it uneconomical for extraction of bran oil (Aravllo et al. 1976).
In this paper the energy requirement of for rice processing at commercial level is discussed. There are two types of mills engaged in rice processing i.e. conventional and modern rice mills. Conventional rice mills: Conventional rice mills are the units, in which the paddy processing is carried out by using steel hullers, an age old technology which is inefficient. Different activities like cleaning, drying, grading, polishing etc. are carried out manually. Modern rice mills: Modern rice mills are the units, in which the paddy processing is carried out by using rubber roll shellers, a modern technology which is more efficient. Majority of the activities are carried out using machineries like driers, aspirators, graders, polishers etc. Different stages of paddy processing in commercial rice mills are followed viz., parboiling process, drying of parboiled paddy and finally milling operation to get finished product.
Indented cylinder paddy separator or triers have, on the other hand, the differences in kernel length as their basic separating characteristic and have been using in seed cleaning and grain milling industry (Grochowicz, 1980). Yamashita et al. (1979) and Yoshitomi et al. (1980) studied the separating mechanisms and the factors affecting the performance of the broken rice separator of indented cylinder type. Later, they conducted experimental tests in an attempt to use an indented cylinder separator for separating rough rice from brown rice in rice hulling process (Nguyen et al., 1987).
Paddy husker is using a blower system
Posté le 17/4/2018 à 03:49 - 0 Commentaires - poster un commentaire - Lien
paddy husker is used to separate grain of rice and husk using a blower system. The system utilizes the difference in specific gravity between rice and husk. Husk which has a smaller specific gravity to be sucked by the blower, while rice tend not to be affected by the air blower and straight out through the rice outlet.
Paddy rice huller uses two pieces of rubber roll as a means of breaking the un-hulled rice. Both roll is mounted adjacent (parallel) with a certain distance and rotated at different speeds in opposite directions. Roller that rotates at high speed is called main rollers or fixed roll, while the other roll is called auxiliary rollers or moveable roll. The main roll is mounted on a stationary shaft while the auxiliary roller mounted on a shaft whose position can be shifted to adjust the distance (gap) between the two roll. Auxiliary roll speed should be slower for about 24% of the main roll.
The rice whitener, which determines the quality of processing, is the key milling equipment in the rice processing line. The control of whiteness (degree of milling) and percentage of broken kernels is done by skilled workers who adjust the pressure door in the outlet, according the color, translucent, temperature etc. of the milled rice. Due to the low cost of electricity at night, rice processing mills usually produce at night. It will make the workers who operated rice whitening machine very tired. All the facts together with the poor working environment (noisy and dusty) which may cause workers leave, will result in unstable production quality.