Design and Experimental Study of a Combined Pneumatic Plot Seed-metering Device for Cotton

Abstract

This study presents a combined pneumatic seed-metering device (SMD) that could not only fill, carry, and meter seeds, but also switch quickly between seed-metering and seed-cleaning modes, and clean seeds thoroughly and rapidly. The seed-filling, seed-carrying, and seed-metering modes of the SMD were analyzed based on a theoretical kinematic model. Furthermore, a three-factor, three-level orthogonal test was conducted by using a performance test bench arranged for the SMD as well as Design-Expert software. The combination of parameters that led to the lowest mis-seeding rate (0.59%) was as follows: an air pressure of 2.67 kPa, a slot width of 2.83 mm, and a seed-metering speed of 20 r/min. The optimized scheme that resulted in a relatively low multiple-seeding rate (4.3%) and met other requirements at the same time was as follows: an air pressure of 2.35 kPa, a slot width of 2.78 mm, and a seed-metering speed of 20 r/min. A field test was subsequently performed by using a combined pneumatic plot cotton planter prototype. While the mis-seeding and re-seeding rates obtained from the field test were both somewhat higher than those obtained from the laboratory bench test, they still met precision planting requirements. The field test validated the accuracy of the theoretical analysis and bench test and served as a foundation for future prototype production and popularization.

Influence of Rotational Speed of Seed Plates on the Quality Seeding in Laboratory Operating Conditions

“…Authors [21] examined the performance of a pneumatic vacuum seeding system. The test was performed in the laboratory and cotton seedplates with a hole diameter of 3.5 mm and a different number of holes (22,30,36,40,48,60,72) were used. The rotational speed of the seedplates ranged from 0.15-0.85 m/s.…”

“…The highest values of the QFI index were achieved at a rotational speed of 0.35 m/s in seedplates with 22, 40, 48 and 60 holes. Authors [22] state that a vacuum of 2.67 kPa at rotational speed of seedplate of 20 min −1 with hole diameter of 2.83 mm achieved a MISS Index of 0.59%. They also state that the same rotational speed of the seedplate at reduced vacuum to 2.35 kPa at a hole of 2.78 mm results in relatively low MULT Index values (4.3%).…”

Performance Parameters Optimization of a Three-Row Pneumatic Precision Metering Device for Brassica chinensis

“…Singh et al [6] designed a cotton metering device to achieve precision in spacing by optimizing the running speed of the metering tray, vacuum pressure and the entry shape of the suction hole. Liu et al [7] designed a combined cotton metering device. After optimization, the optimal combination that achieved the lowest missed seeding index (0.59%) was as below: a vacuum pressure of 2.67 kPa, a slot width of 2.83 mm, and an angular velocity of 20 r/min.…”