Baghouse dust evacuation: Can your system handle surge-flow effects from offline filter cleaning?
When bag filters are cleaned offline by an on-demand cleaning system, a sudden surge flow of dust is released into the baghouse hopper. If this sudden flow isn't rapidly and completely evacuated, the accumulated dust can compact, bridge, and plug the hopper, leading to maintenance headaches and premature bag filter failure.
In many bulk solids processing and handling operations, a baghouse equipped with several filter compartments, each containing several rows of bag filters, is used to clean dust from the process air. These multicompartment baghouses are commonly found in mining and minerals, cement, lime, and gypsum applications and in applications with high-temperature process air, such as power-generating plants, smelters, and foundries. In a multicompartment baghouse, each compartment is typically isolated for offline cleaning. The offline cleaning instantly releases a surge flow of dust from the filters that drops into the dust hopper below each compartment. This large volume of dust suddenly depositing in the hopper far exceeds the volume of dust entering the hopper during the baghouse's steady-state filtering operation (that is, while air and dust are entering the baghouse inlet and dust is depositing on the filters).