HIGHLIGHTS:
It is highly desirable to improve the performance of the existing separation sieve through redesign.
The new sieve has solved the contradictory problem between the potato detection rate and the potato skin breakage rate.
Reducing the potato skin breakage rate during potato harvesting can increase farmers’ income.
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.
Key words:
potato harvest; kinematic characteristics; separating sieve performance
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1 - Frame ground; 2 - Crank; 3 - Connecting rod of first order sieve surface; 4 - First-order sieve surface and boom; 5 - Connecting rod of second-order sieve surface; 6 - Second-order sieve surface and boom; 7 - Connecting rod of third- order sieve surface; 8 - Third-order sieve surface and boom; A - Axis of crank; B - Connection point of crank and drive shaft; C, E, G - Articulated position of sieve frame and boom; D, F, H - Articulated position of the boom and the sieve; X - Orientation of the sieve surface; Y - Direction of vertical sieve surface
1 - Soil cutting disc; 2 - Frame; 3 - Crank; 4 - Dynamic input shaft; 5 - Gearbox; 6 - Chain drive mechanism; 7 - Lifting chain; 8 - Sieve frame; 9 - Boom of third-order sieve surface; 10 - Boom of second-order sieve surface ; 11 - Third-order sieve surface; 12 - Second-order sieve surface; 13 - First-order sieve surface; 14 - Second- and third-order sieve surface connecting rod; 15 - First-order sieve surface connecting rod; 16 - First-order sieve surface suspension rod; 17 - Walking wheel; 18 - Connecting rod
CV - Coefficient of variation; R2 - Coefficient of determination; * - Significant at p ≤ 0.05; ** - Significant at p ≤ 0.01; ns - Not significant