Real-time solid flow velocity measurement based on a microwave sensor

Abstract

Measurement and control of bulk solid flows become increasingly important in industries, such as large-scale production, coal transportation and food processing, although rapid and accurate velocity measurement is still a challenging task in these applications. This paper presents a new velocity measurement method based on a microwave sensor operated at 10.525 GHz and investigates the factors that affect velocity of bulk solid flows and the velocity of the solid particles in order to quantify the flow and improve the efficiency of transportation. In this method, a microwave Doppler Signal Analyser is adopted to calculate the average velocity of bulk solid flows and obtain the instantaneous velocity of a single solid flow. The influence of air friction, pipe collision and particle interactions is also analysed with experiments. The measurement results show that the average velocities of bulk solid flows range from 0.6 to 1.6 m/s, and the interaction between solids play a major effect on solid movements. The effect of pipe wall friction should also be considered. Besides, the mass flow rate and the total mass of bulk solid flow can be calculated. The mass flow rate ranges from 0 kg/s to 0.21 kg/s in the entire experiment.

A novel microwave Doppler method for mass estimation of machine-picked seed cotton

“…Gao [27] established a soybean mass using soybeans mass between 100 g and 1000 g, and randomly selected mass ranging from 200 g to 1000 g to validate the model. Zou et al [16] randomly selected green beans within the range of 2-3 kg for mass model validation. Yang et al [2] randomly selected fertilizers ranging from 1.3 kg to 2.7 kg for flow model validation by controlling the turning speed of the manure spreader axis.…”

“…Yang et al obtained the velocity and concentration of fertilizer particles through the Doppler signal processed by the fast Fourier transform (FFT), defined the product of velocity and concentration as the output value of the sensor, and used the least squares method to establish the relationship between the output value of the sensor and the mass flow rate of the fertilizer, and the model was verified by the experiment, and the relative error was not more than 10.04% [2]. Zou et al [16] designed a microwave sensor to measure the velocity of solid particles from the Doppler effect, and then use the velocity measurement process to get the power signal, analyze the power and weight relationship and fit the equation. Through the test, verify how the antenna installation position affects the measured power, and propose measures to improve the problem.…”

Design and testing of a microwave Doppler-based yield estimation system for machine-picked seed cotton

“…verified the existence of a certain relationship between the total mass of flowing solids and the power of the echo signal in the laboratory, which provided a new way of thinking about the detection of solid mass flow, and triggered the study of solid mass flow detection using similar methods. For example, Ma Xin et al [16] designed a microwave-based yield monitoring sensor to establish a linear relationship between power spectral density and soybeans, and after experimental verification, the average error of measurement is low 8%; Zou Jing et al [17] designed a microwave sensor to establish a model for the relationship between echo power and particle weight, and the experimental results show that the measurement error of the flow mass is within 13.01%. Yang Liwei et al [18] developed a microwave method based on the particle fertiliser mass flow measurement system, the establishment of two kinds of compound fertiliser mass flow and sensor output value of the linear regression model, the test detection of the relative error is not more than 10.04%.…”