For small capacity, hand work is ok, can make labor use well, while if for large capacity, hand work may can not satisfy with the machine work, and too much labor work together may a little waste of time, and also can not promise work efficiency, so a destoner machine is necessary, designed special for the destoner work, mechanical work can promise work efficiency and also can clean the stone out better than hand work, a good pre work partner for the paddy husker.

The bounce of a paddy grain on the blade was neglected in the dynamics equation as well as the law of proportion. In this report, rotating coordinates that rotate at the same angular velocity as that of the dehulling fan, were introduced. The two laws of proportion, i. e., with respect to rotational angular velocity and similitude ratio, were proved to be valid not only for the rotating coordinates but also in the bounce equation. Through experiments of a paddy grain falling in a vacuum chamber, the bounce was recognized as a probabilistic phenomenon, but it became evident that the mean values of bounces satisfy the law of proportion and the bounce equation.

Paddy hulling and whitening are two principal stages in rice milling. To carry this process and use of machinery in this field can significantly reduce waste. The research was carried out to determine role and type of huller machine and its adjustment on rice breakage. Two types of huller, rubber roll and Engelberge in three level of hulling for Hashemi variety were studied. Whitening process was carried out on samples in Engelberge whitener. Breakage percentage, milling yield and rice whitening degree were determined. The result showed that breakage percentage was affected by type of huller machine but hulling percentage had no significant effect on breakage amount. Rubber roll huller could reduce breakage percentage of hashemi variety up to 2.58% (rice weight base) and %5.4 (paddy weight base).yield result showed that the type of huller machine and amount of hulling had significant effect on milling yield. The milling yield of Hashemi variety were %66.3 and % 63.07 in rubber roll huller and Engel Berge huller, respectively. Whitening result showed that the type of huller machine and hulling percentage had significant effect on degree of rice whitening. Degree of rice whitening with Engel Berge huller was more the rubber roll huller.

Rice processing machines produced in developed countries are mostly unaffordable by rural farmers, hence there was need to develop cost effective/efficient machines produced from available local materials desirable in food industry that meets the need of the rural farmers. This study was to evaluate the performance of a developed rice dehusking/destoning machine at Federal University of Agriculture, Abeokuta, Nigeria. Minitab 16 was used for analysis of variance of two main factors [four paddy varieties Faro 35, Faro 44, Faro 55 and Ofada and five moisture content (MC) groups] to obtain its optimum operational parameters. Cleaning efficiency, coefficient of dehulling, coefficient of wholeness, dehulling efficiency, dehulling recovery and output capacity were optimum at 94.60%, 0.63, 0.85, 50.54%, 61.22% and 18.53 kg/h respectively. The effect of MC and test paddy variety on coefficient of wholeness and dehulling efficiency were significant while only MC effect was significant at P