Influence of operating parameters on cake formation in pilot scale pulse-jet bag filter

Bag filters are commonly used for fine particles removal in off-gas purification. There dust laden gas pervades through permeable filter media starting at a lower pressure drop limit leaving dust (called filter cake) on the filter media. The filter cakeformation is influenced by many factors including filtration velocity, dust concentration, pressure drop limits, and filter media resistance. Effect of the stated parameters is investigated experimentally in a pilot scale pulse-jet bag filter test facility where lime stone dust is separated from air at ambient conditions. Results reveal that filtration velocity significantly affects filter pressure drop as well as cake properties; cake density and specific cake resistance. Cake density is slightly affected by dust concentration. Specific resistance of filter cake increases with velocity, slightly affected by dust concentration, changes inversely with the upper pressure drop limit and decreases over a prolonged use (aging). Specific resistance of filter media is independent of upper pressure drop limit and increases linearly over a prolonged use.

Specific resistance increase with increasing filtration velocity at constant dust concentration.Figure optionsDownload as PowerPoint slideSpecific resistance of filter media is independent of pressure drop limit while that of the cake decreases.Specific resistance of filter media increases linearly and that of filer cake decreases on aging.Highlights
► Specific cake resistance depends on velocity, pressure drop limit and aging.
► Pressure drop limit influences the cake formation at higher levels only.
► Dust settling decreases at higher velocity and vice versa.
► Filter media resistance is independent of upper pressure drop limit.
► Filter media resistance increases linearly on aging.