Effects of number of vanes, vane angle and disc peripheral speed on the distribution uniformity of twin-disc granular fertilizer broadcaster

The aim of this study was to determine the effects of the number of vanes, vane angle and disc peripheral speed on the uniformity of transverse and longitudinal distribution in two-disc granular spreaders. The experiments were carried out with spherical fertilizer, 3 different numbers of vanes (2 - 3 - 6), 5 different vane angles (17° - 30° - 43° - 56° - 69°) and 5 different peripheral speeds of the disc (13.85 - 15.05 - 16.26 - 17.46 - 18.67 m s^-1) with a full factorial experimental design in accordance with ASAE 341.4 and TS 2541 standards. During the operation of the machine, the best working condition in terms of the uniformity of the transverse distribution (CV_xvers, %) was obtained with a disc peripheral speed of 15.05 m s^-1, an angle of 56° and the use of 2 vanes. In this working condition, the CV_xvers (%) of 8.31 % was found, while the working width was calculated to be 16.22 m. Regarding the uniformity of fertilizer distribution in the longitudinal direction, the lowest CV_long (%) was found at a disc peripheral speed of 17.46 m s^-1 and a vane angle of 69° when only 2 vanes were used.