CFD Investigation of a Partly Pit Ventilation System as Method to Reduce Ammonia Emission from Pig Production Units

The objective of this work was to investigate the efficiency of a partly pit ventilation system with cleaning of the air exhausted from the pit. The analysis, including Computational Fluid Dynamics (CFD) methods, showed that evacuating and cleaning of 10% of the total ventilation capacity from a pit may reduce the ammonia emission of the system by 73%, and the ammonia concentration in the room was significantly reduced. In a similar production system without pit ventilation cleaning of 10% of the ventilation capacity reduced the ammonia emission by 41% compared to no cleaning. A drawback of the pit ventilation system is that it increases the ammonia release from the slurry surface by 26% and, consequently, may increase the operating cost of a cleaning system in order to remove this extra ammonia.