Study On Fire Suppression Performance Of Superfine Powder Extinguishing Agent Based On Cup-burner

Superfine powder extinguishing agent is a new kind of halon alternative. In order to study the fire suppression characteristic of the powder, firstly, based on the ingredients of the extinguishing agent, by ultra-attenuation and surface modification, superfine powder extinguishing agent was made and agent comprehensive properties were tested. Secondly, based on cup-burner, a set of intact fire suppression experiment platform was built and designed. The experiment platform solved the powder quantified transport problem. The experiments were carried out based on different powder mass flow and n-heptane and alcohol flame. The experiment results show that with the increasing of the powder mass flow, the fire suppression time becomes shorter at first then becomes longer. The concentration of powder from 90.5 to 154.8g/m3, could lead to fire suppression. Compared with n-heptane flame, alcohol flame is easier to extinct.Then, to study the powder characteristics influence on fire suppression, by the methods of SEM and TGA, the surface structure and thermal decomposition feature of the powder were analyzed. The flowing diffusion feature of the agent was simulated with Fluent software. The simulation focused on gas-solid velocity and solid concentration distribution at certain powder volume fraction in cup-burner. SEM test result shows that the diameter of powder is small, the distribution of powder is good and there is a lot of salient on powder surface. The salient increases the specific surface area of the agent and could lengthen contacting time with the flame. TGA result shows that the mass loss rate of the powder can reach 50%at 800℃. The simulation results show that at certain powder volume fraction, with the velocity increasing of carrier gas, the gas-solid vecolity also increases and the maximum velocity appear at the medial axis of the cup-burner. By the two sides of medial axis, the agent comcentration is larger and more stable. Besides, with the flow incressing, gas-solide velocity and agent concentration will increase. Reflux phenomenon can also be strengthened too. All these findings can lengthen powder contacting time with flame and improve the suppression performance of the agent.