Thermal mass flow meters are used in combination with Continuous Emission Monitoring (CEM) systems for stack gas monitoring (flue gas) or air emission monitoring.
Stack Gas Flow Measurement
Stack gas is generated from many combustion sources, including incinerators, kilns, and thermal oxidizers. A thermal oxidizer is a process for the treatment of air exhaust and is commonly used during the incineration of waste. When the stack is mixed with air, the exhausting gas is cool enough to be measured by a thermal mass flow meter, thereby getting the benefit of the fast response and wide turndown of the device. Measuring the flow rate of stack gas is required in order to calculate the overall mass of gas over time. This is a requirement for many environmental regulations.
Stack Gas Flow Profile
Stack flows are relatively high volume and in large stacks or ducts. A single point measurement does not give a truly representative sample of the overall flow profile, therefore multiple thermal flow meters are used and the customer can average these readings in their control system. In these situations, the sensors are positioned at the point of equal areas in the stack.
Conventional versus Mass Flow Meters
Conventional flow meters are not mass flow devices, and they are affected by the temperature and pressure of air flow. In contrast, Sage Prime Thermal Mass Flow Meter will report the direct mass flow of flue gas emitted with and no separate temperature and pressure corrections are needed.