Lab Investigation of Thermal Anemometers for Mass Flow Measurements in Harsh Operating Conditions

Argon purging is a process in steel production where liquid metal is flushed with argon gas to remove impurities. It is an essential processing part for high quality steel production. For process control, reliable flow measurements of the amount of purging gas are required. However, due to the situation in the steelworks, the measurement of the flow must be done directly at the injection. At this position an energy autarkic measurement system is required, which puts energy constraints to the application of flow metering techniques. The harsh operating conditions at this position make this measurement even more challenging. Currently, no off-the-shelf measurement system exists. In this work, we investigate the feasibility of lower power thermal anemometry for flow metering in the present application. Different sensing elements and operational modes for thermal anemometry are studied and analysed by means of test rig measurements. Finally, an uncertainty evaluation is presented, which provides an approach for the setting of the operational conditions of such a sensor.