Investigation of the different particle size dust releases from rigid filter candles during pulse-jet cleaning

Abstract

Rigid filters made of ceramic or metal are widely used to remove solid particles from hot gases at temperature above 260 °C in the petrochemical and coal industries. Pulse-jet cleaning of fine dust from rigid filter candles plays a critical role in the long-term operation of these filters. In this study, an experimental apparatus was fabricated to investigate the behavior of a 2050 mm filter candle, which included monitoring the variation of pressure dynamic characteristics over time and observing the release of dust layers that allowed an analysis of the cleaning performance of ISO 12103-1 test dusts with different particle size distributions. These results showed the release behavior of these dusts could be divided into five stages: radial expansion, axial crack, flaky release, irregular disruption and secondary deposition. The cleaning performance of smaller sized dust particles was less efficient as compared with larger sized dust particles under the same operating conditions primarily because large, flaky-shaped dust aggregates formed during the first three stages were easily broken into smaller, dispersed fragments during irregular disruption that forced more particles back to the filter surface during secondary deposition. Also, a “low-pressure and long-pulse width” cleaning method improved the cleaning efficiency of the A1 ultrafine test dust from 81.4% to 95.9%.

Influence of precoating on the regeneration efficiency of filtration inorganic membranes

“…Their results noted that a convergent nozzle with a diameter of 12 mm at a distance of 60 mm from the diffuser achieved better cleaning performance than a straight nozzle. Luan et al 7 studied the effect of pulse-jet parameters on the regeneration efficiency of inorganic membranes, whereby reducing the pulse pressure and extending the pulse width improved the membrane regeneration efficiency from 81.4% to 95.9%. However, the aforementioned methods still face challenges in effectively addressing the pore blockage of membranes due to fine particles and limited applicability under different dust-removal operating conditions.…”

“…Their results noted that a convergent nozzle with a diameter of 12 mm at a distance of 60 mm from the diffuser achieved better cleaning performance than a straight nozzle. Luan et al 7 . studied the effect of pulse‐jet parameters on the regeneration efficiency of inorganic membranes, whereby reducing the pulse pressure and extending the pulse width improved the membrane regeneration efficiency from 81.4% to 95.9%.…”