A triple deck, parallel belt screen for farmer stock peanuts

摘要

Belt screens currently used in the peanut industry separate farmer stock peanut materials into two size categories based on diameter. Utilizing belt screens for obtaining more than two size categories requires two or more screens with different spacings between belts for each screen. A modification of the belt screen design was developed incorporating three screen decks into a single machine. The three decks provide the ability to separate small foreign materials, large vegetative foreign materials, and loose shelled kernels and small pods from farmer stock peanuts. The machine was equipped with fixed spacings appropriate for screening farmer stock peanuts (cv. Florunner) for performance testing. Round belts (1.27 cm dia.) for the three decks were spaced on sheaves to provide 0.64-, 1.03-, and 2.54-em openings between belts. Screen capacity and separation performance were evaluated by varying material feed rates and belt speeds. Belt speeds evaluated were 105.2, 117.3, 130.0, 140.7, and 152.4 em/sec and feed rates varying from 5170 to 27,210 kg/hr. An average of 91.55% of the sample weights was divided into the 10.3-mm < diam. < 25.4-mm separation. Compared to prescreening sample composition, the average LSK percentage was reduced by 6.39% and FM by 7.36% in the 10.3-mm < diam. < 25.4-mm separation. Within the ranges tested, derived equations indicated that feed rate and belt speed had limited effects on separations. The openings between the belts appeared to influence material separation more than feed rate and belt speed.