What situations in the laboratory need to use a fume hood?

As long as there is a toxic and harmful substance crisis during the experiment, it is necessary to use a fume hood to protect or reduce the degree of harm to humans or the natural environment. Toxic and harmful substances that are harmful to people need to be protected by fume hoods, and toxic and harmful substances produced in the natural environment need to be recycled and controlled. This is why recently fume hood manufacturers have paid more and more attention to exhaust gas treatment.

Fume hoods are an integral part of laboratory ventilation design. In order to prevent laboratory workers from inhaling or swallowing some toxic, pathogenic or unknown chemicals and organisms, the laboratory should have good ventilation. To prevent the absorption of some vapors, gases and particulates (smoke, soot, dust and aerosols), contaminants must be removed by means of fume hoods, hoods or local ventilation.

The most important function of the fume hood is the exhaust function. In the chemical laboratory, various harmful gases, odors, moisture and flammable, explosive and corrosive substances are generated during the experimental operation. In order to protect the safety of users , to prevent the pollutants in the experiment from spreading to the laboratory, and use a fume hood near the pollution source. In the past, the number of fume hoods was small, and it was only used in experiments with particularly harmful and dangerous gases and large amounts of heat.

Types of fume hoods

The types of fume hoods mainly include movable fume hoods, bypass fume hoods, supplemental air fume hoods, natural ventilation fume hoods, top extraction fume hoods, and slit fume hoods. Different industries have different requirements for fume hoods.

1. Movable fume hood: In modern laboratory buildings, a general laboratory (experiment hall) is sometimes equipped, in which the experimental workbench, basin fume hood and other equipment can be moved at any time, and can also be pushed in when not in use. Adjacent storage room. Such fume hoods should preferably be made of wood, plastic or light metal for ease of movement.

2. Bypass fume hood: When the laboratory considers the amplitude fume hood to exclude indoor air, it is ideal to use this fume hood, because the indoor ventilation volume is not affected when the cabinet door is fully closed.

3. Supplementary air fume hood: For laboratories or clean laboratories with air conditioning systems, this type of fume hood is ideal, which not only saves energy, but also does not affect the airflow organization in the room.

4. Natural ventilation fume hood: the advantage is that it does not consume electricity; it can continuously exchange air day and night (according to the actual measurement, the indoor ventilation can reach 6 times/h), which is conducive to indoor ventilation; no noise and vibration; because there is no mechanical equipment, it is easy to Maintenance; simple structure, low cost. However, its use is limited by certain conditions. It should not be used in experiments with high toxicity and no heat generation, and some rooms should not be used in summer.