How does the exhaust system of a fume hood work

The exhaust system of the fume hood is its core component. It mainly operates based on negative pressure and local air supply to ensure the safety of the operators in the laboratory and effectively remove the harmful gases and substances produced during the experiment. The following is the working principle and process of the fume hood exhaust system:

First, working principle

The exhaust system of a fume hood mainly relies on the fan to generate negative pressure, which sucks the indoor pollutants into the fume hood and then discharges them outdoors through the exhaust system. Meanwhile, the fume hood also forms a certain air flow barrier inside the fume hood through local air supply, preventing harmful gases and particles from spreading into the laboratory.

Second, workflow

Start the fan: When the laboratory personnel begin the operation, start the fan of the fume hood. The fan starts to operate, generating negative pressure, which causes the air pressure inside the fume hood to be lower than that outside, thus creating a negative pressure environment.

Inhaled pollutants: Under the effect of negative pressure, the air inside the fume hood and the harmful gases and particles produced during the experiment are sucked into the fume hood. These pollutants are sent into the exhaust system through the evacuation passage of the fume hood.

Filtration and purification: In the exhaust system, pollutants first pass through filters for purification treatment. Filters can effectively remove particulate matter and chemical substances from the air, ensuring that the discharged air meets environmental protection requirements.

The air that has been filtered and purified is discharged outdoors through the exhaust duct and the action of the fan. In this way, a continuous air circulation cycle is formed in the laboratory, ensuring the cleanliness and safety of the experimental environment.

Third, key components and functions

Fan: The fan is the core component of the exhaust system, responsible for generating negative pressure and promoting air flow.

Filter: Filters are used to purify particulate matter and chemicals in the air to ensure that the discharged air meets environmental protection requirements.

Exhaust duct: The exhaust duct is responsible for discharging the purified air to the outside while maintaining air circulation within the laboratory.

Control system: The control system is used to monitor and control parameters such as the exhaust volume and face velocity of the fume hood, ensuring the normal operation of the fume hood and the safety of the laboratory personnel.

Fourth, Precautions

Regular inspection and maintenance: The exhaust system of the fume hood needs to be inspected and maintained regularly to ensure its normal operation and effective removal of pollutants.

Set the exhaust air volume reasonably: According to the specific requirements of the experiment and the type of fume hood, set the exhaust air volume reasonably to achieve the best ventilation effect.

Pay attention to operational safety: During the experiment, the experimenters should abide by the operating procedures, avoid bringing flammable and explosive items into the fume hood, and ensure operational safety.

In conclusion, the exhaust system of the fume hood effectively removes harmful gases and substances produced during experiments through negative pressure and local air supply, protecting the safety of laboratory personnel and maintaining the cleanliness of the experimental environment.