Abstract: In order to solve the problems of low cleaning rate and high damage rate of spherical crispy fruits during the cleaning process, the differential speed principle of brush roller was adopted to design a washer with dual-speed brush rollers for fruits which had the functions of soaking, brushing, spraying and collecting fruit. Its basic structure and working principle were explained, and its key components such as soaking device, spraying device, brushing device and so on were designed and analyzed. Red Fuji apple was selected as the test material. The rotation speed of the odd-numbered brush rollers, the rotation speed of the even-numbered brush rollers, and soaking time were taken as test factors. The cleaning rate and damage rate were used as evaluated indicators. The single factor test was executed to determine the levels of factors. Through the orthogonal test with three-factor and three-level, the significance of the influence of the test factors on each test index was analyzed, and the optimal cleaning parameter combination for fruit cleaning was determined. The results showed that the rotation speed of the odd-numbered rows of brush rollers was 80 r·min^-1, the rotation speed of the even-numbered brush roller was 100 r·min^-1, and the soaking time was 25 s. Under these conditions, the fruit cleaning rate was 98.08%, and the damage rate was 3.07%.

Key words: agricultural machinery, washing machine, spherical and crispy fruit, brush roller, differential speed