AMC Power has incorporated our unique flow-measuring technology into a device designed specifically for measuring airflow into cyclone burners. This schematic shows the typical configuration of ten-foot cyclones in a common windbox.
 

Because it would be difficult to test such a device on a furnace with multiple cyclones in a common Windbox, we have utilized our test chamber, designed to AMCA standards, in Santa Rosa, CA to test the product. The test chamber consists of a large plenum (windbox) which houses a "mock-up" of a cyclone inlet (B&W drawings were utilized to create the "mock-up"). We have simulated turbulent conditions caused by obstructions in the windbox and by the cyclone itself. This was accomplished by modulating the split dampers on the exhaust and by utilizing a variety of obstructions at the cyclone inlet to replicate actual windbox conditions. We have tested this flow-measuring device through the same velocity (flow) range that the cyclone would experience in service. The results have proven the product we have developed can be used to accurately/repeatably measure flow to each cyclone. The end result will be that it can be used to balance airflow to each cyclone in a furnace, and thus lead to increased furnace performance and decreased NOx levels. Another immediate benefit is the inlet screens (bells) can be removed which will allow for the removal of as much as 12 IN.. w.c. of permanent pressure drop in the system. This will yield more fan capacity, which should prevent the need for rework or replacement due to FD-limited situations. In addition to secondary airflow, we are also building flow stations for the primary/tertiary inlets to a cyclone burner for evaluation.
 

Not only are the inlet screens a tremendous waste of fan energy, they are also an ineffective way of measuring flow. These systems were designed to be calibrated using a Pitot tube. Inserting a Pitot tube in such a turbulent environment has proven to be a futile way of calibration. In addition, inlet screens can be damaged over time as shown here, resulting in major altering of initial calibration coefficients. Removal of the screens and installing AMC Power Combustion Airflow Stations will result in more accurate information that can be used to optimize boiler performance. Not only can this information be used to increase efficiency through burner balancing, it can also be used to bias burners for achieving lower NOx.
 

This system is currently installed in many cyclone boilers across the country and is a proven means to help balance airflow, reduce NOx and increase plant efficiency. AMC Power offers solutions for all windbox configurations and cyclone types (single damper, split damper, with "blanking plate", etc).

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AMC Power Application Bulletin