Synergistic Action of Deep Filtration and Surface Cleaning – Operational Mechanism of Ceramic Fiber Filter Tubes

The operational mechanism of ceramic fiber filter tubes is based on the synergistic effect of "deep-bed filtration" and "surface cake filtration." When dust-laden flue gas enters the filter tube, the gas stream is driven by differential pressure to permeate through the fiber layers of the tube wall, while dust particles are captured by the fibers through mechanisms including inertial impingement, interception, diffusion, and gravitational settling. The tube wall consists of multiple layers with different pore sizes—the outer coarse-fiber layer serves to intercept large particles and form an initial dust cake, while the inner fine-fiber layer is responsible for capturing fine dust, achieving high-precision filtration. This gradient structure design allows dust to be progressively captured across the thickness direction of the tube wall, simultaneously reducing operating resistance and extending the cleaning cycle.

As the filtration process continues, a dust cake gradually builds up on the outer surface of the filter tube. This cake itself participates in the filtration, further enhancing the collection efficiency for submicron particles. When the cake thickness increases to the point that the system pressure drop reaches a preset value, the pulse backwashing system injects high-pressure gas into the tube, causing instantaneous expansion and vibration that dislodges the surface cake into the hopper, thereby regenerating the filter tube. After cleaning, the tube maintains its original filtration performance and can be reused repeatedly. This cyclic "filtration–cleaning–regeneration" mode ensures long-term stable system operation without the need for frequent shutdowns for maintenance.