Compartment Air Distribution Monitoring System

Foster Wheeler is leading the power generation industry with innovative products that reduce NOx into the "ultra low" range. Compartment Air Distribution Monitoring, or CADM, is our signature product for controlling secondary air in tangentially fired boilers.

CADM measures relative secondary airflow through every air and coal compartment. These measurements are used by a unit's DCS system to modulate individual air dampers for control of secondary air distribution through each compartment. Each damper can be modulated to even the distribution on an elevation or, when relative coal flow by corner is known, bias can be introduced into the system to match air flow with coal distribution. In this manner individual burner stoichiometry is achieved and combustion performance is enhanced. This improvement is as important to boilers as the conversion in the automobile industry from carburetors to fuel injection.

CADM systems receive pressure differentials in a central location from sensing lines routed from each compartment. The differential pressures are measured continuously for real time conversion to relative airflow in proprietary signal conditioning cabinets. This data is fed by Ethernet using OPC server for integration with existing plant DCS.

CADM can also be combined with Foster Wheelers Electric Charge Transfer (ECT) system for continuous, real time air and coal flow management. Operating in this manner maximizes balanced combustion to minimize CO and unburned carbon in flyash. More information on ECT Systems can be found here.

The figure to the right shows a typical DCS screen view of the real time airflow distribution data obtained from the CADM system. Several screens are available showing air mass flow, nozzle velocities and damper bias information.