摘要
In crop production,the mean condition for high productivity depends on singular seed holding in metering device of sugar beet planters.A general design of vertical or horizontal feeding disc is only to plant the coated sugar beet seeds due to the irregularity of surrounding shape of seeds.The paper is focused on developed and constructed vertical brush metering device to plant the ordinary types of sugar beet seeds(multi or mono germs).The physical properties of sugar beet seed species have influences on the behavior of vertical brush metering device.To evaluate the vertical brush metering device,some properties of sugar beet species were determined and some experimental results of planting were identified in this paper.The main dimensions(length,width and thickness),sphericity,geometric and arithmetic mean diameter,surface area,bulk density and true density were identified as physical parameters.Meanwhile,the terminal velocity,and hardness were measured as engineering properties.The static coefficient of friction for multi-germ seeds under different surfaces(stainless steel,sheet galvanized,plastic and rubber)were 0.48±0.42;0.51±0.56;0.57±0.34 and 0.72±0.53 respectively,while they were 0.26±0.57;0.28±0.38;0.30±0.34 and 0.36±0.74 for the mono-germ seeds respectively under the above mentioned surfaces.The regressions analysis for the relationship between the main parameters of sugar beet seed indicated that the highest positive effective factors affecting the approximation physical sugar beet seeds properties is the width of sugar beet for multi-germ while the length is more effective for mono-germ seeds.The vertical brush metering device is one key part of sweet sugar beet planter;it was evaluated by assessing the actual relationship between the three density of hair per hole(50,75 and 100 hair/hole)and the feeding device parameters(seeding traveling and peripheral speeds of metering device).The seeds flow in brush device was controlled by seed lever control which lies in seed tank bottom.All parameters were measured at different levels of brush device with four peripheral speeds(0.16;0.24;0.32;and 0.4 m/s).Feeding quality,missing seeds,multiple indices and precision of seed index are the most common characteristics used to evaluate the metering device performance.The highest seed feed index was achieved on the brush device with hair density of 100 hair/hole for two different sugar beet varieties(Multi-germ of 83.07%and mono-germ of 80.56%).The lowest seed feed index was obtained from the experiments using the hair density of 50 hair/hole with peripheral brush speed of 0.4 m/s.The lower values of precision index indicate better performance of the brush device,therefore the lowest values were found at seeding speed of 2.0 m/s,0.3 m/s peripheral speed of feeding device and 100 hair/hole densities.
