Industrial smoke extractors
Introduction
A fume hood, fume hood, fume hood or fume hood is a local Collective Protection Equipment, ventilation device "Ventilation (architecture)")[1] that is designed to limit exposure to hazardous or harmful chemicals, fumes, vapors or dusts. They fulfill a similar mission to the extractor hoods existing in many kitchens "Kitchen (room)"), to evacuate the fumes produced, but fume cupboards are commonly used in laboratories of all types, e.g. research laboratories, and pilot plants, where they work with polluting gases.
In Europe, the reference standard for its design, testing, validation, use and maintenance is EN 14175, made up of several parts:
Part 1: Vocabulary.
Part 2: Safety and performance requirements.
Part 3: Type test methods.
Part 4: "In situ" test methods[2].
Part 5: Recommendations for installation and maintenance (Published as technical specification CEN/TS 14175-5).
Part 6: Variable air volume fume cupboards.
Part 7: Fume cupboards for high temperatures and concentrated acids.
History
Scientists and researchers have understood the need for ventilation since the beginning of chemical research. Older styles of fume hoods were types of chimneys.[3] A hearth built by Thomas Jefferson in 1822-1826 at the University of Virginia used a "sand bath") and flues to vent toxic gases.[4]
Structure
A fume cupboard is an essential piece of laboratory equipment. It has a horizontal surface or work area, which is usually located at a height that allows working while standing. Its approximate dimensions are 1-2 meters in length, 80-90 cm in depth and 240-270 cm in height. The side walls can be made of glass, on the front they are equipped with a sash window.
For its operation it requires an extractor that forces the aspiration of the gases or fumes produced.
Types of fume cupboards
There are two main types: ducts and recirculation (with filters). The principle is the same for both types: air is sucked in from the front (open) part of the box to dilute and remove the gases with which it is working. This mixed air can be expelled outside the building to a safe place by extractor/fan or recirculated in the laboratory after passing through the filter.