Journal of Researches in Mechanics of Agricultural Machinery

Journal of Researches in Mechanics of Agricultural Machinery

Online measurement of bulk solids mass flow rate based on centripetal force

Document Type : Original Article

Authors
1 Department of Agricultural Machinery Engineering, Faculty of Agricultural, University of Tehran, Karaj, Iran.
2 Department of Mechanical Engineering of Biosystems, Faculty of Agriculture, University of Tehran, Karaj, Iran.
Abstract
An accurate, reliable, online, no-effect passing materials, continuous and non-invasive measurement of solids’ mass flow rate in conveying pipelines has been a technically challenging area, which becomes increasingly significant to achieve efficient utilization of energy raw materials and to reduce waste. In this study, a grain flow rate meter based on the centripetal force was designed, constructed, and evaluated. Initially, Discrete Element Method (DEM) analysis was performed to evaluate the easy passage of granular materials without obstructing the passage of materials in the device, as well as to determine the velocity of material passage on the measuring pan for three different rates of wheat 15.62, 32.90 and 66.75 kg/s. According to the results for three different fall rates, the velocity of the material on the measuring plate was 2.55±0.018 m/s. In the first stage of the evaluation, load cell calibration was done using standard weights from 100 to 1800 N with steps of 100 N and for validation from 5 to 500 N with steps of 5 N. Finally, the load cell calibration was confirmed with a coefficient of determination above 99% with RMSE=3.88 N. Then, the apparatus was evaluated for specific amounts of wheat in seven different amounts from 5 to 35 kg with 5 kg steps with a random shedding rate. The results showed that the device is able to measure the rate of granular material shedding with very high accuracy (determination coefficient above 99% and mean absolute percentage error 0.55%).
Keywords

Subjects