Measurement of bulk material flow based on laser scanning technology for the energy efficiency improvement of belt conveyors

Bulk material flow is the key variable of speed control technology and is responsible for the improving energy efficiency in belt conveyors. This paper presents the design and verification of a mathematical model intended for the measurement of bulk material flow on belt conveyor using laser scanning technology. This problem is solved using the method of non-contact measurement, which can acquire the surface profile of bulk materials moving on a belt conveyor in real-time using a laser scanner and a belt speed monitor. A contour extraction solution is proposed in accordance with the space's morphological characteristics and the material flow outline in one frame. By integrating the element areas of the bulk material cross section, a mathematical model to calculate the flow rate of bulk materials on moving belt is established. The main advantage of these models is that the measure accuracy is less affected that previous model by the uneven distribution and intermittence of bulk materials. The concept of the experimental rig at Wuhan University of Technology of China is designed so that it represents a 3.5 m long belt conveyor system on which bulk material flow detecting experiments can be conducted. When the belt operates at speed of 0.5 m/s, 1.0 m/s and 1.5 m/s, the repeatability, the correlation and the variation coefficient of the measurement value are more than 98%. The experimental results prove the excellent characteristics of the new device for real practice because the characteristics correspond to real operational conditions. The obtained results are useful for analysing belt mechanical properties under real operational conditions and for optimising operating procedures of belt conveyor systems. (C) 2015 Published by Elsevier Ltd.