The primary purpose of fume hoods in laboratories is to exhaust chemical fumes, vapors, gases, dust, mist, and aerosols. Additionally, fume hoods:
- Act as physical barriers between experiments and the lab.
- Preventing inhalation of chemical fumes.
- Prevent chemical spills.
- Prevent run-away reactions.
To prevent contaminants from escaping the hood, it maintains a relatively negative pressure inside while drawing air through the hood opening at a constant rate. A suitable hood face velocity is crucial to achieving safe and effective fume hood operation. Excessive face velocities can reduce containment and create turbulence, but insufficient velocities can make hoods less effective. The important parts of a fume hood include baffles, hood body, sash, airfoil, face, exhaust plenum, and work surface.
Some important highlights
- Waste should not be disposed of in the hood. Whenever possible, the apparatus in a hood should incorporate condensers, traps, or scrubbers for containing and collecting waste solvents, toxic vapors, or dust. It should be practiced to dispose of waste properly and to comply with codes.
- It is not advisable for the fume hoods to store many chemicals. Only keep the minimum amount of chemicals in the hood during the procedure. Ensure you store hazardous chemicals in an approved safety cabinet, such as flammable liquids.
- Keep the hoods running at peak performance by adhering to procedures. If materials or equipment are stored excessively in the hood, an eddy current may form, or a reverse flow could happen, resulting in contaminants being released.
- Reagents should not be left uncapped in hoods. Even though fumes are expelled from the laboratory through a hood, it is still desirable to minimize the amount of evaporation and to fume to protect the environment and operators.
Main Types of Fume Hoods:
- Distillation Fume Hood: It is distinct from others because of its low worktop height, which allows the operator to operate from a highly elevated position. This allows for the installation and mounting of tall distillation equipment in the work chamber. The remaining characteristics of this kind of hood and other typical fume hoods are similar.
- Acid Digestion Fume Hood: Special liners composed of materials such as unplasticized PVC are employed in such fume hoods because of their ability to withstand acid. For acid digestion applications that require high temperatures while being in service, it is possible to employ different types of materials such as PVDF instead. Because they are resistant to the etching caused by hydrofluoric acid, polycarbonate sashes are often used.
- Non-Fume Hoods: It is not uncommon for chemical fume hoods such as biological safety cabinets, laminar flow clean benches, pharmacy isolators, and glove boxes to be mistaken for biological safety cabinets. As a result of particulate filters, these devices cannot eliminate chemical vapors from the air.
- Ductless Fume Hood: The purpose of ductless fume hoods is to adsorb chemical vapors and fumes with the help of activated carbon filtration. This type of hood uses recirculation to deliver air to the laboratory.
General operating instructions when using a chemical fume hood:
In order for a chemical Laboratory fume hood to do its job, please follow these instructions:.
- Remain attentive for variations in airflow while working.
- For optimum efficiency, always keep the hood sash closed.
- Substitute dangerous compounds with ones that are less volatile or less harmful.
- If practicable and safe, while operating within a hood with large equipment, position the equipment on blocks so that air may circulate underneath it.
- To avoid introducing pollutants into the laboratory air, contaminated items should only be removed from the hood after decontamination.
- The hood opening is a dangerous area, so do not walk swiftly past it, use fans, or enter or exit it abruptly. These obstructions will disrupt the airflow of the hood, causing the efficiency to be reduced.
- Discontinue using and completely close the sash if a performance issue is detected or an airflow warning is activated (if you have that feature).
Application of laboratory fume hood
Its main function is discharging waste present in the air of a laboratory or an area. This includes materials such as: chemicals, gases, odors, corrosive or flammable items.
Best Kinds of laboratory fume hood
1.
CHEMICAL FUME HOOD 90CM
With / without suction hose - Duct / DuctLess.
Fume hood, widely applicable in electronics, mechanics, medical, and university labs.
Provide protection to the operator.
2.
DUCTLESS CHEMICAL FUME HOOD (WITH CHEMICAL FILTER), 91 CM
Work Surface Height: 900mm
Max.Opening: 650mm
Air Velocity: 0.25~0.35m/s
Airflow Volume: 105m3/h
Noise: ≤55dB(A)
Fluorescent Lamp: 16W*2
3.
LABORATORY CHEMICAL FUME HOOD 110CM
Fume hood, widely applicable in electronics, mechanics, medical, and university labs.
Provide protection to the operator.
Work surface material:solid chemical-resistant laminate.
Microprocessor control with touch buttons.
Compliance: CE.
Duct length: 4m.
Duct collar size: 10 inch.
Inflow velocity: Average 0.5m/s.