Improved design and experiment of separating sieve for potato digger

ABSTRACT The original two-order separating sieve has a good potato-soil separating ability, but it causes significant damage to potatoes while ensuring a high potato detection rate, which in turn affects the working effectiveness of the potato digger. Thus, it is necessary to improve the design of the original swing separation sieve with a two-order sieve surface to one with a three-order sieve surface to solve the contradiction between the potato detection and potato damage. On this basis, the movement characteristics of potatoes and the separation performance of the new sieve were experimentally investigated. The experiment was conducted in a test field in Wuchuan County using a completely randomized design in a single-factor scheme with three factors and five levels, with five crank speeds (140, 150, 180, 210 and 225 rpm), five machine forward speeds (1.41, 1.51, 1.70, 1.89 and 2.21 km h-1) and five boom-connecting rod length combinations (250-350-1,030, 250-370-1,040, 270-370-1,050, 290-370-1,060 and 310-370-1,070 mm). Each experiment was repeated three times at each level, and the average value was taken as the final result. The experimental results demonstrate that the new three-order separation sieve can ensure a high potato detection rate while maintaining a low potato skin breakage rate.