In recent years, there was many conflagration about special structure such as wooden cultural assets, warehouses and factories. The common causes of increase in the fire damage were difficulty of the initial suppression and absence of equipment for appropriate disaster prevention. A prediction of the air injection diameter of the destruction-spray nozzle, a core technology of destruction-spray fire vehicle which is possible for fire suppression of special structure were studied. As a result, changes in water flow according to the air injection diameter is not large, but air flow rate showed a difference more than up to four times. And then, through the result data of the flow analysis, the air injection diameter was obtained in the target mix ratio of the air according to the water injection pressure. Finally, by the formula derivation for the air injection diameter of target mix ratio of the air, the air injection diameter according to the water injection pressure change could be predicted within an error of 10%.

In recent years, there was many conflagration about special structure such as wooden cultural assets, warehouses and factories. The common causes of increase in the fire damage were difficulty of the initial suppression and absence of equipment for appropriate disaster prevention. In this study, the destruction-spray nozzles, a core technology of destruction-spray fire vehicle which is possible for fire suppression of special structure was studied using the finite element method. As a result, the maximum deviation of the part nozzle was 18.1% compared with the reference value. Second, the maximum deviation of the nozzle module was 13.5% compared with the part nozzle. Third, the safety factor about internal pressure of the nozzle module was suitable as 13.6. Finally, the performance of the designed destruction-spray nozzle was satisfied with 4,652.1L/min in excess of the target performance.