Prototype twin vacuum disk metering unit for improved seed spacing uniformity performance at high forward speeds


Abstract: The objective of this study was to design and develop a prototype twin vacuum disk metering unit so that seeding can be achieved at higher forward speeds while reducing the peripheral speed of the vacuum disk for improved seed spacing uniformity performance and increased field work capacity. In order to meet this objective, a new precision seeding unit with twin vacuum disks, each being a mirrored view of the other and geometrically the same, was designed in animated drafting software and then it was manufactured and used for the laboratory experiments. Three crop seeds were used to determine the performance of the new metering unit in the lab on a sticky belt test stand. Two alternative measures were used to quantify the seed spacing accuracy, and polynomial functions using the principles of response surface methodology were developed to calculate the optimum level of the variables. The tests performed in the laboratory at 2, 3, and 4 ms-1 forward speeds resulted in improved seed spacing accuracy values, while the quality of feed index measure went down once the forward speed increased from 2 to 4 ms-1. The quality of feed index with the new metering unit was obtained to be 100% at 2 ms-1, while it was almost 98% for all crop seeds at 3 ms-1. The forward speed of 4 ms-1 resulted in quality of feed index values of 92%, 96%, and 96% for cotton, sunflower, and corn seeds, respectively.

Keywords: Design, optimization, response surface methodology, precision metering unit, vacuum, hole diameter

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