Design and test of the key components for a combing-type tobacco harvester

In response to the problems of low efficiency,high labor intensity,and low mechanization in manual tobacco harvesting,a comb-off tobacco picking device for southern hilly tobacco areas was designed following the agronomic requirements and the principle of manual picking of tobacco harvesting in southern China.The device was composed of the power chassis,picking mechanism,and storage mechanism.This study involved the theoretical analysis,structural design,and modeling of the key components,such as chassis structure,combing-type picking mechanism,and power synchronization mechanism.The results of the motion analysis and calculation of the picking process demonstrated that the adjustment range of the comb chain elevation angles was from 12.4°to 20.9°,the comb rod installation distance was 76.2 mm,and the synchronizing mechanism transmission ratio was 3:10.One-factor test and three-factor three-level orthogonal test was performed with the forward speed of the chassis,the distance between the picking device baffles and the elevation angle of the chain with the combing bar as test factors,and the rate of broken and missed tobacco picking as evaluation indicators.It was revealed that the optimal combination of the forward speed of the chassis,the distance between the baffles,and the chain elevation angle were 1.5 km/h,75 mm,and 12.4°,respectively.Moreover,verification tests suggested that the breakage rate of tobacco leaves was 9.99%,and the probability of missed tobacco picking was 7.31%,both of which satisfy the agriculture requirements and the operational requirements in the agricultural machinery certification syllabus.

Field test and cost analysis of four harvesting options for herbaceous biomass handling

The nature of most biomass materials is a low bulk density as compared to traditional fuel sources.High handling cost could be a limiting factor in utilizing biomass feedstock.Understanding available harvesting machinery systems and associated costs is critical to future implementation.Four popular harvesting machinery systems were studied and costs were analyzed based on field measurements and calculations.These four systems included(1)round baling and round bale handling systems,(2)large square baling and square bale handling systems,(3)forage harvester and trucking systems,and(4)large square baling plus square bale compression systems.Results indicated that a self-loading forage wagon can reduce the cost to harvest a crop but requires more harvest time.Large square bales were found to reduce cost of handling and transport as compared to round bales.Further research is needed to determine storage costs and deterioration loss of the two bale types.Compressed square bales were found to reduce storage,handling and transport costs.Compressed bale machinery has a high initial cost,which currently makes only valuable for hay export.