A Triboelectric-Nanogenerator-Based Gas–Solid Two-Phase Flow Sensor for Pneumatic Conveying System Detecting

The particle concentration and the mass flow rate are the most important parameters describing the gas–solid two-phase flow. Herein, a novel method based on triboelectric nanogenerator is proposed for measuring a particle concentration and the mass flow rate in a gas–solid two-phase pipe flow. The as-fabricated gas–solid two-phase flow triboelectric nanogenerator (GS-TENG) consists of one acrylic base plate, one copper electrode, and one stripe of polytetrafluoroethylene (PTFE) membrane. Different materials can be detected by the GS-TENG, including organic material, such as flour, and inorganic materials, such as copper and soil. PTFE surface morphology is modified to improve the output performance of the GS-TENG in the experiments in order to detect the output electrical signal more efficiently. The peak output current generated by the gas–solid two-phase flow in the GS-TENG shows a mostly linear relationship with the concentration and mass flow rate. In addition, the transferred charge in the process of the flow also shows a highly linear relationship with the concentration and the mass flow rate, which is consistent with the theoretical derivation for the single electrode TENG. The experimental results demonstrate that the measurement error of the GS-TENG is less than 2%.