The latest technology in air flow measurement for the cement industry

摘要

Difficult process stream conditions have prevented on-line air flow measurement for hot dusty applications in cement plants in the past. This paper discusses technology that measures the velocity of high temperature (1100/spl deg/C (2000/spl deg/F)) dust laden gas streams. The system utilizes the triboelectric principle by aligning two metal rod sensors parallel to the longitudinal/flow axis of the duct. Electrical signals created by dust particle clouds passing the upstream and downstream sensors are cross correlated and referenced by their time shift. The time shift and distance between probes provides a flow velocity. This measurement method has no drift and thus requires no calibration, and imparts no pressure drop to the system. Various applications at different cement plants was discussed to illustrate how the ability to measure dust laden gas flows has improved monitoring, control, and process optimization of the cement making process.