In this study, the researcher investigated the effects of water mist nozzle shape on water mist according nozzle shape angle(=30°, 45°, 60°, 75° and 90°). It was found that the water mist spray with nozzle When exit angle of water mist nozzle is =90° as result examining about spray special quality of water mist, velocity distribution was expose to maximum. And temperature distribution of target plate was looked tendency that range low. Water mist spray system that consider in this research is one of the most important utilities providing water mist in order to supply fire extinguishing.

This research has so far found out problems including the second damage of extinguishant and the short time of emission when using the existing dry chemical extinguisher and gas type extinguisher, and impossibility of constant extinguishing due to the inability of recharge at the field. To solve such problems, a mobile water mist system was developed and used. However, it is judged that more improved mobile water mist system is necessary because the force of the fire changed diversely and remote villages in mountains or islands where the force of fire extinguishing is short or delayed, require high capacity of fire extinguishing. Therefore a new equipment was developed and tested focusing on the improvement of extinguishing capacity and the performance of extinguishing was found out to be improved, compared to the existing mobile water mist system. It also showed a superior extinguishing capacity to dry chemical extinguisher or gas type extinguisher. Afterward an additional research is required of simplification of equipment, price cutting and the development of additive to enable high performance even with just small extinguishant.