DEM study on threshing performance of “compression–oscillation” thresher

Abstract

Threshing of wheat is a fundamental post-harvest operation to isolate grains from straw, leading to further processing and storage. This study introduces a promising and power-efficient technology named as "Compression-Oscillation" threshing, which relies on cyclic frictional squeezing rather than beating as in conventional threshers. Discrete element method simulation was used to model the physical characteristics of wheat spikes and grains as well as interaction properties such as bonding, coefficient of restitution, static and rolling friction. Concave clearance and rotor drum speed sensitivity were studied in terms of compressive force and threshing performance in the system. The achieved threshing efficiency is 98.0% at rotor drum speed of 350 rpm at concave clearance of 4.5 mm and throughput of 6 tons per hour. Results indicate that this technology could supersede the existing beater technology. Determination of wheat grain detachment strength, role of oscillation on the wheat grain bonding strength and development of full-scale commercial machine are suggested as future work.

Study of the Process of Threshing Leguminous Grass Seeds With a Drum-Type Threshing Device

“…An analysis of the operation of drum-type devices for threshing grass seeds shows that the main factors affecting the completeness of seed extraction are the exposure of the heap processing and the operating modes of the device (Khawaja & Khan, 2022). However, one should take into account the possibility of injury to seeds due to fatigue load with an increase in threshing exposure (Wang et al, 2023).…”