Mechanical dust collectors have been used with biomass-fired boilers for more than 60 years. Today, they are primarily integrated into air handling systems as a “precleaner” that removes ash and sand particles from flue gas, thereby extending the operational life of induced draft (ID) fans and pollution control equipment.
A secondary role that has developed for mechanical dust collectors used in biomass-firing systems is to separate coarse char particles that have a high BTU value from flue gas. With the right reclaimer system, collected char can be re-injected into the boiler to increase biomass boiler efficiency as much as 2 percent.
Mechanical dust collectors are easy to integrate into almost any air handling system because they are simple devices that do not have any moving parts. Composed of a square or rectangular housing containing a number of cyclones (i.e., tube assemblies) arranged in parallel, mechanical dust collectors use both centrifugal force and gravity to remove particulate from flue gas emerging from boilers. Generally, they can collect 85 percent of particles that are 15 microns or larger.
Prior to the changes to the Environmental Protection Agency (EPA) industrial emission standards made in the 1980s, mechanical dust collectors were used as the primary air pollution control (APC) devices in most biomass-fired boiler systems. The new role of system “precleaner” was established after the adoption of these stricter EPA regulations.
Mechanical dust collectors have been found to be highly effective in other boiler systems that burn coal/bagasse/sludge, lime/cement/carbon black kilns, and with pelletizing iron ore/coke equipment. By varying the size of the collector’s inlet tubes, discharge boot, shape (conical or periphery), and electing to include hood turning vanes or not, air handling engineers can design mechanical dust collectors to suit almost any installation, increasing system efficiency and preserving equipment with relatively little investment.
To learn more about the history and benefits of mechanical dust collectors, visit our Learning Center and download a copy of the article “Evolution of the Mechanical Dust Collector in Biomass Applications” by ProcessBarron Dust Collector Product Manager Philip Gore. You can also call 1-888-663-2028 and speak to Philip directly.