Liquidation of ammonia clouds using a mobile turbine rescue and firefighting system

Abstract

Given its extensive industrial use and chemical properties ammonia is a source of serious hazards in the event of its uncontrolled releases. The mobile turbine rescue and fire-fighting system (MTSRG), equipped with a special SO3-W aircraft turbine with 10 kN power and water efficiency of 6 m3/min, can be used to liquidate spatial gas clouds by diluting them with combustion gases and sorption on the surface of the produced water microdroplets. The publication presents calculations related to the effectiveness of the system during the uncontrolled release of ammonia from a pressure vessel. To estimate the performance of this system, use was made of water stream droplet size research, kinetics studies of ammonia sorption, SO3-W turbine parameters at a safe working distance, as well as results of ammonia concentration simulation using the ALOHA program. A combined simulation carried out for a rupture of DN100 pipe supplying liquid ammonia to spherical tank with a diameter of 16.6 m and filled in 70% showed that it is theoretically possible to reduce the ammonia concentration by as much as 95.75% while the vehicle is operating at a working distance of 60 meters from the rupture. The exhaust gases together with the entrained air contribute mainly to the reduction of the concentration of ammonia through the mechanism of dilution (91.6%). Water mist generated by the vehicle is theoretically responsible for the reduction of ammonia concentration by only 4.15%.