Published by AIP Publishing, researchers in Japan have developed a desktop air curtain system (DACS) that blocks all incoming aerosol particles.
“We expect the system to be effective as an indirect barrier to use in blood labs, hospital wards, and other situations where it cannot be maintained sufficiently,” said co-author Kotaro Takamure. physical distance, such as at the front desk.
One air curtain, or louver, is a fan-powered ventilation system that creates an air gap over an inlet. Hospitals use them to prevent ambulance fumes and other contaminants from entering the interior of the emergency room.
One challenge in developing smaller air curtains is to completely block the aerosol particles emitted over time because it is difficult to maintain a wall of air over long distances. As a result, the devices gradually lose their aeration intensity, creating a turbulent flow that allows infected aerosol particles to escape to the surroundings.
DACS has an exhaust and suction port to help solve this problem.
A generator at the top of the DACS generates air, which is directed to the intake port at the bottom of the unit. This prevents airflow dispersion, thus resulting in the collection of all aerosol particles at the intake port.
A highly efficient particulate air (HEPA) filter can be installed inside the intake port to filter the air.
The researchers are developing an accompanying virus inactivation system equipped with an ultraviolet light that connects to the suction port. After the air is cleaned with UV light, it is recirculated to maintain the airflow of the air curtain and the air pressure in the room.
The researchers tested their device using an air compressor connected to a dummy to simulate breathing.
Dioctyl sebacate, a widely used solvent with the ability to spread readily, has been added to the air stream to produce aerosol particles. Particle image velocity measurement and a high-speed camera were used to determine the blocking effect of DACS.
The aerosol particles approaching the DACS are suddenly bent towards the suction port, indicating that
the air curtain completely blocked all aerosol particles from entering.
When the researchers placed the mannequin’s arm over the DACS to mimic a blood draw scenario, they noticed that the airflow above the arm was disrupted. However, the aerosol suppression performance remained unaffected.
DACS was tested on patients during blood collection at Nagoya University Hospital. The researchers are looking at lowering the suction port, so that the arm can be placed below the heart for proper blood collection.