TEST OF THE SCREENING AND PARAMETER OPTIMIZATION OF SWING SEPARATION SIEVE IN FIELD OPERATION

The need for clarity regarding the sieving characteristics of the potato-soil mixture, as provided by the swing separating sieve of a potato digger, as well as the derived problems of low potato transportation efficiency, a high potato damage rate and low potato unearthing rate, are the main reasons for this study. Dynamic tracking technology is proposed to collect the motion state of potatoes, during the process of potato and soil separation. Considering the potato conveying speed, potato unearthing rate and potato damage rate as indicators, while the sieving parameters (crank rotational speed, sieve inclination, crank radius and swing direction angle) are the influencing factors, an orthogonal regression test is carried out, where the response surface is used to analyze each factor, its influence on the screening index, and to optimize it accordingly. The test results show that there is a linear relationship between the screening parameters and indexes, with each parameter showing different contribution rates to the screening indexes. The best parameter combination is the crank rotational speed of 190 r/min, sieve inclination of 9.7 degrees, crank radius of 40 mm and swing direction angle of 18.8 degrees. The corresponding potato conveying speed, unearthing rate and damage rate is 0.713 m/s, 98.7% and 3.224%, respectively. After optimization, the potato conveying speed is 1.43 times higher, the unearthing rate is increased by 2.5% and the damage rate is reduced by 60%. The research results can provide theoretical support to the structural design of potato diggers.