Fire Safety Science Digital Archive

Spray bitumen fires often occur in buildings and industrial processes. To investigate this type of hazard, the burning behavior of this flammable mixture was tested under practical conditions. Investigations of the suppression of this typical kind of fire were also included. CFD simulations were used as supplementary validation of tests that assessed the suppression of this type of fire by application of water mist. The water mist was generated from a centrifugal nozzle operating at low pressure about 1.0 MPa. The characteristics of the water mist were tested by LDV/APV system. The fuel was sprayed using the same sprayer as the sub-sprayer of the water mist nozzle. The flame structure was observed by the Thermograph (TG, SATHY6850). The various temperatures were tracked every 1 second by the K-type thermocouple. The flame suppression processes were observed and analyzed using a Charge Coupled Device (CCD) video camera. All the experiments were carried out in a 3 m × 3 m × 3 m confine space. Results indicated that the highest temperature of the spray bitumen fire was recorded in the core of the spray. The spray bitumen fire could be suppressed effectively by using the water mist fire suppression system. For lower pressure of the spray bitumen, the water mist suppression demonstrated higher efficiency. The test results showed that there was a short-lived “fire enhancement” phenomena as long as the water mist was released into the spray fire. Also, using the FDS to simulate the spray bitumen fire, we found comparative results between the numerical and experimental results.