Novel exterior cover design for radiant heat resistance of firefighting robots in large-scale petrochemical complex fires

Fires in petrochemical complexes are inaccessible because of the intense radiant heat from flames. Therefore, water cannon robots require radiant heat countermeasures to perform firefighting safely. Conventional radiant heat countermeasures employ a self-spraying method, wherein the water cannon robot requires a water tank of capacity 1.5 m³ (= 1500 L) to function for 7–8 min in an environment with a 20 kW/m² radiation heat. However, the water cannon robot has size limitations because it is transported on one transport vehicle (10 t truck) to the site, and only a tank of capacity ~ 0.02 m³ can be installed on the robot. To overcome these drawbacks, this study proposes a method that utilizes a mountable radiant heat-resistant exterior cover that works with a small amount of water. The cover is made of radiant heat-shielding fireproof clothing with an aluminum coating that reflects 90% of the radiant heat on the surface and a mist nozzle that sprays water on the back surface. The remaining 10% is removed by the heat of vaporization of water sprayed on the back of the clothing and natural convection. The amount of water required for cooling was reduced to 1/80th of that compared to self-spraying because of the use of the developed cover. The proposed method of radiation reflection via vaporization and natural convection can be employed to protect firefighting robots.