Air curtains combined with smoke exhaust for smoke control in case of fire: Full-size experiments

Abstract

This paper analyses the possibility of using air curtains to prevent smoke flow from fire compartments. Full size experiments have been carried out and several relevant conditions to assess smoke-tightness have been tested. The smoke temperature during the tests was ranging from 182ºC to 351ºC, the angle measured between the curtain axis and the vertical plane was ranging from 18º and 26º, the nozzle thickness was ranging from 0.017 m to 0.045 m and the velocity at the nozzle was ranging from 8.3 m/s to 19.9 m/s. During the tests, the air curtain’s nozzle was positioned horizontally at the top of a permanent opening (door). With this configuration, we obtained an approximately vertical downward jet through the used opening. This paper includes the final results of the tests and develops an analytical tool for predicting the performance of air curtains. It was concluded that it is possible to achieve smoke-tightness, provided that the adequate plane jet parameters and the compartment’s smoke exhaust are correctly adjusted. According to this analysis, the smoke-tightness limit corresponds to equation B=〖ΔP〗_a⁄〖ΔP〗_s =-0.30 u_a⁄u_(a_min) +1.25 (with 1.30≤ u_a⁄u_(a_min) ≤1.67).