Abstract:The air-suction seed metering device can realize precise seed metering of small particles, but the low sphericity of celery seeds and the agronomic requirements of multiple seeds in one hole bring difficulties to the accurate seed metering research of celery. Aiming at this problem, a celery precise seed metering device was designed and developed with a group of suction holes by using CFD flow field simulation, vacuum derivation, and bench test. Taking celery seed “Ventura” as the research object, firstly, the shape and size of the suction hole were determined according to the triaxial size of the celery seed. Secondly, the CFD flow field simulation determined the numbers of group suction holes. Thirdly, vacuum degree theory determined the lowest negative pressure of seed suction. Finally, a three factors and three levels orthogonal test was carried out with vacuum degree of gas chamber, the rotational speed of seeding plate, and distribution structure of suction hole as test factors, and the missed sowing rate, replaying rate and qualified rate as test indexes. The primary and secondary elements, and the optimal parameter combinations affecting seeding performance were determined using range and variance analyses. The experimental results showed that when the optimal combination parameters of air-suction celery precision seed metering device comprised of vacuum degree of -4kPa, seed disk speed of 20.75r/min, and distribution structure of holes being an equilateral triangle, the qualified rate of seeding was 88.9%, the missed seeding rate was 5.1%, and the replaying rate was 6.0%. Field test demonstrated that the qualified rate of seeding was 83.48%, the missed seeding rate was 9.15%, and the replaying rate was 7.37%. The research realized precision hill-drop planting of celery with an air-suction seed arrangement device.
