A new logarithmic congestion model for vent sizing and reduced pressure prediction in baghouse dust collectors

Baghouse dust collectors are recurrent sources of industrial dust explosions, yet current vent-sizing standards (NFPA 68, EN 14491) consistently under-predict the reduced pressure that develops in these highly congested vessels. This study presents a new logarithmic congestion model that incorporates the effect of internal filter volume directly into the classical vent-sizing equation. The correlation is calibrated with a series of full-scale deflagration tests and verified against computational-fluid-dynamics simulations. Compared with the standard NFPA approach, the new model delivers markedly closer agreement with measured reduced pressures across a wide range of dust reactivities and congestion levels. It captures the characteristic behaviour whereby the installation of the first filter rows causes a sharp rise in pressure, followed by a gradual plateau as additional filters are added. By embedding turbulence amplification directly into vent-sizing curves, the model enables realistic prediction of blast loads on collector panels, vent frames, and anchorage systems without resorting to time-consuming CFD. The proposed correlation thus offers loss-prevention engineers a rapid, physically consistent tool for designing explosion-relief systems in baghouse collectors, helping close a long-standing safety gap in the process industries. • Current standards do not account for blast amplification due to obstacles. • Internal obstacles significantly increase blast pressure in vented enclosures. • Logarithmic congestion factor significantly improves vent sizing accuracy. • Mean residual is + 0.3 kPa, indicating no systematic underestimation. • Nomograms enable quick blast load design for vented dust collectors.