A fast elimination technology of fine smoke particles by charged water spraying

Large amounts of fine particles in fire smoke can reduce the visibility and hinder the escape of trapped people. Comparing to the traditional methods, this study proposes a fast elimination technique using charged spraying. The influences of charged voltage (0, 4, 8, 12 kV) and spraying flow rate (100, 200, 300 mL/min) on smoke elimination efficiency are investigated experimentally. It is observed that charged spraying exhibits a higher elimination efficiency than the gravitational sedimentation and uncharged spraying. It takes only 2 min for charged spraying to reach the safety threshold, which is one-sixth the time of uncharged spraying. The charging and atomization characteristics of spraying are also analyzed to study elimination mechanism. The charge-to-mass ratio is found initially increases and then decreases with electro voltage, while the droplet sizes of spray reduce statistically with higher voltages and flow rates. The corresponding mechanisms of smoke particle elimination are supposed to two aspects, higher collision probability and greater attraction between the charged droplet and smoke particles. However, it is also found that excessive flow rate will cause light-blocking effects, reducing transmittance. This study provides new possibility for rapid smoke elimination in fire scenarios.