Harmful chemicals can enter your lungs and or the bloodstream and can result in dizziness causing permanent liver damage over the years. The only way that those working with harmful samples and toxic products can prevent contamination is through Laboratory Fume Hoods that filter the air inside the laboratory. These either come with ducts or are ductless. Fume hoods with ducts remove the air from the chamber and dispense it into the atmosphere. Many ducted hoods employ constant air volume (CAV) systems, the new generation hoods work on variable air volume (VAV), which reduces the exhausted air volume as the sash of the hood is closed.
In ductless hoods, the air is recalculated and filtered before it is redistributed back in the laboratory. The filtration process varies according to the material. When the material behavior is known to the user and the material is not subject to change, the ductless hood is used.
Fume hoods are designed for various incidents that include small explosions and fire. Therefore fume hoods must be properly installed to provide complete safety for the user. The sash acts as a shield that can sustain the impact of an explosion and if there is an explosion the glass will spider and not shatter out of the hood. The user must always remember to shut the hood when not in use. If an explosion occurs the glass will fall inside the enclosed hood and will not potentially harm the lab personnel.
What is the working of a fume hood?
This ventilated enclosure contains gases, vapor, and fumes; the exhaust fan on the top of the fume hood draws the air and the airborne contaminants through the ductwork exhausting them in the atmosphere. Modern Fume hoods are movable and come with a front sash and interior baffle. The sash can be vertical or horizontal depending on the design. It can be a combination of both providing adequate protection for the user with a barrier that shields the worker from the communicable sample being worked on. The slots and baffle direct the exhausted air and many hoods allow the evenest flow, therefore the baffles must not be closed or blocked as that would interfere with the path of the exhausted air. The hood face is surrounded by an airfoil or beveled frame that stops sharp curves to create turbulence.
Constant volume hoods maintain a constant rate of the exhaust flow rate or air pulled. With the lowering of the sash, the cross-sectional area of the hood opening decreases and there is a proportionate increase of the face velocity. When the sash is lowered the face velocity is increased.
Variable air volume
A variation is observed in the exhaust flow rate and the air pilled quantity through the hood as the sash is adjusted to maintain face velocity. With the lowering of the sash, the cross-section area of the hood opening decreases while the velocity of the airflow remains constant with less total air volume being exhausted.
When is the fume hood misused?
The Laboratory Fume Hoods should not go through procedural adjustments without adequate evaluation. A poor adjustment will result in decreased performance. You should consult with the company if you wish to adjust your fume hood. Connect with https://www.igenels.com/ for details on the working and maintenance of fume hoods.
———————————————-
iGene Labserve 