Precision Metering System Design for Variable Rate Granular Fertilizer Applicator

摘要

A variable rate fertilizer metering mechanism was designed by changing the speed of the feed shaft. A microcontroller unit programd with a Pulse Width Modulation (PWM) motor driver was used to run the feed shaft at varying speed. Two types of fluted rollers (straight and helical flutes) were used with varying numbers of flutes having same volume for each flute. The physical properties of di ammonium phosphate and single super phosphate granules were measured. The geometrical mean diameter of DAP andSSP were 4.48 +0.28 mm and3.76+0.33, respectively. There were no significant differences between helical and straight fluted roller with varying numbers of flutes (6 and 8) for discharge rate. The discharge rate of SSP fertilizer was significantly higher than that of DAP.