Indoor air quality management in environments with ammonia contamination presents significant challenges for occupational health and safety. Air curtain ventilation technology has emerged as an effective solution for ammonia gas removal and contaminant control in various settings including livestock facilities, industrial processing plants, and laboratory environments. This innovative ventilation system utilizes strategically positioned high-velocity air streams that create invisible barriers, preventing cross-contamination while facilitating the efficient extraction of ammonia emissions and noxious gases. The presented study uses ANSYS Fluent to model ammonia removal by an air curtain ventilation system.

Figure 1: air curtain ventilation system in a laboratory

Simulation Process

The ammonia enters the zone from the bottom side. Three outlets are installed on the ceiling and equipped with an air curtain. The model is created and meshed in Design Modeler and ANSYS Meshing, respectively. It is perfectly clear that two species of air and ammonia are needed that require activation of Species Transport model. The high-velocity air acts as a carrier flow that hastens the removal process.

Post-processing

The images show how ammonia distribution looks in the cross-shaped air curtain setup. In the first picture, we can see the NH3 concentration shown by different colors. The red and yellow areas (highest concentration) are mostly where the air curtains cross each other, while blue areas (lowest concentration) are at the edges. This pattern shows that the cross-shaped design creates invisible walls that keep ammonia gas from spreading throughout the whole space. The clear boundaries between different concentration zones show that the air curtain works well even when dealing with high amounts of ammonia.

Figure 2: air curtain system removes ammonia from the laboratory

The second and third pictures show how air moves through the system, helping us understand why the ammonia stays contained. In the middle of the room, air streams come together and move upward at speeds up to 4.4 m/s. These upward air flows act like exhaust paths that move ammonia away from where people might be. The even flow patterns shown in the streamlines mean that pressure is balanced across the system, which helps the air curtain work steadily. Around the edges, air circles back around, which helps keep ammonia inside the controlled area while using less energy by reusing some of the already cleaned air.

Figure 3: Air curtain flow pattern as streamlines