Development and control of an aerial extinguisher with an inert gas capsule

Fire extinguishment approaches with inert gases such as carbon dioxide (CO₂) and nitrogen (N₂) have several advantages compared with ones with water. On the other hand, they have low extinguishment performance and put lives at risk. To enhance the extinguishment performance and to reduce risk to life, the authors have proposed a robotic fire extinguishment approach and a prototype of an aerial extinguisher with an inert gas. The prototype can transport only a small volume of an inert gas, and it can extinguish a very small flame. In this paper, we develop a quadcopter type of aerial extinguisher with a rubber balloon filled with helium. The extinguisher is easily adapted to the volume of helium by changing the length of rods between the motors and the center. It is shown that the extinguisher can be controlled by using a depth sensor. It is also demonstrated that the extinguisher with 5 L of helium achieves flame extinguishment for a diffusion flame of methane with a 10 L/min. flow rate.