Advanced cartridge design for a gas respiratory protection system using experiments, CFD simulation and virtual reality

Gas masks are critical for protection against chemical, biological, radiological, and nuclear materials. Efforts are underway to develop advanced cartridges for next-generation gas respirators in civil-military combined use to improve wearability and protection for users (firefighters, military personnel, and environmental and safety related workers). Herein, the performance of three newly designed cartridges for a next-generation gas respirator was evaluated using flow analysis, along with adsorption characteristics. The adsorption kinetics of cyclohexane gas on ASC (a copper-silver-hexavalent chromium impregnated activated carbon in the study) was measured by breakthrough experiments in a packed bed, and the obtained parameters were used in the computational fluid dynamics (CFD) model for the designed plate-type cartridges. To apply the physical properties of the adsorbent to the CFD simulation, porous materials were expressed using the granular technique and packed bed technique. The CFD model was verified through a gas adsorption experiment using a prototype cartridge. The respiration resistance and breakthrough time for the filled-adsorbent efficiency and lifespan were compared among the three designed cartridges according to the gas inflow conditions. Additionally, virtual engineering was performed by grafting the CFD results to a virtual reality (VR) system with which 3-dimensional performance visuals of the cartridges could be observed. The developed VR system provides detailed information for cartridge design and optimization. Overall, the developed procedure of virtual engineering can be used to improve CFD simulation results.