Industrial Filtration
Raise the air-to-cloth ratio to buy fewer bags and pressure drop rises with the square of it. The fan pays that bill every hour of every shift.
— Pa
Media plus cake at the current point in the cleaning cycle
The cake resistance K2 is treated as a constant, but it depends on particle size distribution, moisture and how compressed the cake is, and a fine or damp dust can multiply it — it must come from measurement on the actual dust, not from a table. Media resistance K1 also drifts upward over bag life as fines embed permanently, so the residual drop after cleaning climbs across a bag set and the pulse interval shortens with it. Perfect cleaning back to bare media is assumed here and never happens in practice.
Baghouse Filter Cake Pressure Drop & Pulse Timing — free, with the formula and a worked example, at Textile School.