An air curtain is used to ensure an adequate separation between two compartments that is aimed to restrict, a clean one and a contaminated one. The air curtain performance is improved with the use of an air extraction from the “contaminated” compartment. The aerodynamic sealing of an optimized air curtain is assessed regarding particulate matter. The evaluation using visual assessment of the aerodynamic sealing using a cold smoke source is validated against PM 10 detection. It is shown that the air curtain presents a good aerodynamic sealing for the particulate of PM10 and PM2.5 classes and that the visual assessment method can lead to similar results. An equation was obtained with a view to be used to predict the level of aerodynamic sealing of the air curtain when the exhaust rate becomes too low. Another equation was obtained for predicting the average velocity through the door protected by the air curtain required to obtain an aerodynamic sealing, as a function of the jet parameters (nozzle average velocity and thickness). These test results prove that the air curtain, complemented with an air exhaust from the “contaminated compartment”, is suitable to provide an acceptable aerodynamic sealing for the particulate matter. Practical application: The findings of this research are applicable when it is necessary to retain the contamination due to particulate matter using a soft boundary, as air plane jets. This is applicable to medical care centres to reduce the possibility of contamination due to bacteria between different compartments or in pharmaceutical process units to avoid cross contamination among them.

Vertical air curtains are often used to separate two different zones to reduce contaminant transfer or even to provide aerodynamic sealing from one zone to the other. In this isothermal full-size experimental research work, the contaminant transfer between zones is reduced using an air extraction from the “contaminated” compartment and an air curtain. This work correlates the minimum exhaust air flow rate required to reach the aerodynamic sealing at the opening connecting two different zones with the jet nozzle velocity for small nozzle thicknesses (5 mm, 10 mm and 16 mm), particularly for Reynolds numbers below 3800. Following the experimental study, a general physical law that relates the jet parameters (angle, nozzle thickness and jet velocity at the nozzle) with the average velocity through the opening (for the condition of acceptable contaminant tightness) was obtained. The results showed that the average velocity of the flow across a door protected by an air curtain required to keep the aerodynamic sealing varies linearly with Re. The slope, however, is different below and above Re = 3820.