Operation technological process research in the cleaning system of the grain combine

Abstract

The purpose of this study is to increase the efficiency of the technological process of a combine harvester cleaning system. It involved the simulation of the actual work process, the identification of problem areas and the uniform airflow distribution across the width of the sieve mill. The method for determining the class of ‘air-grain heap’ flow in the combine harvester cleaning system is presented in order to provide the mathematical description of its technical work process. As a result, the volumetric (Q = 8·10–6 ÷ 2.5·10–4) and mass (W = 0.01 ÷ 0.3) concentration of a grain heap in different sections of the sieve mill of the combine harvester cleaning system. The experimental measurements of the airflow speed on the sieve mill’s surface for the existing structures of the cleaning system in modern grain harvesters were 3.75 ÷ 10.2 m/s. The data obtained will be used in the future to implement a mathematical model for a complete description of the technological process of a combine harvester cleaning system using methods based on two-phase flow mechanics.

Cross-flow fan on multi-dimensional airflow field of air screen cleaning system for rice grain

“…The flow coefficient of the cross-flow fan is approximately proportional to the size of the impeller diameter. In a certain shape and size, the characteristic curve of the cross-flow fan will be affected by the shape and size of the volute [20] . The impeller of the cross-flow fan adopts forward arc blades.…”

“…The chaffer with the adjustable opening is used as the main type in the cleaning system. The opening of the screen is designed to be between 0-36 mm, and the screen surface inclination α=(±10)° [ 20] . In order to make up for the uneven distribution of the axial airflow of the centrifugal fan, the method of connecting two fans in series is used to solve this problem, and the inclination angle of the air outlet of the centrifugal fan is 25° [ 21] .…”