Views: 0 Author: Site Editor Publish Time: 2023-03-10 Origin: Site
A fume hood (sometimes called a fume hood or fume hood) is a local ventilation device designed to limit exposure to noxious or toxic fumes, vapors, or dusts.
A fume hood is typically a large piece of equipment that encloses a work area on five sides, with its base usually at standing working height.Two main types exist, ducted and recirculated (no duct).The principle is the same for both types: air is drawn in from the front (open) side of the cabinet, and either exits the building or is filtered to safety and returned to the room.This is used for:
Prevent users from inhaling toxic gases (fume hoods, biosafety cabinets, glove boxes)
Protection of products or experiments (biosafety cabinets, glove boxes)
Protection of the environment (recirculating fume hoods, some biosafety cabinets, and any other type of fume hood if appropriate filters are installed in the exhaust stream).Secondary functions of these devices may include explosion protection, spill control and other functions required to get the job done within the device.Fume hoods are typically set against a wall and often have padding above to conceal the exhaust ductwork.Because of their recessed shape,they are often difficult to illuminate with normal interior lighting, so many interior lights come with a moisture shield.In front is a sliding window, usually glass, that moves up and down on a counterbalance.In educational versions,the sides and sometimes the back of the unit are also glass, so multiple students can see into the fume hood at the same time.Low airflow alarm control panels are common.
Fume hoods are typically available in 5 different widths; 1000mm, 1200mm, 1500mm, 1800mm and 2000mm with depths varying between 700mm and 900mm and heights between 1900mm and 2700mm Variety.These designs can accommodate one to three operators.For particularly hazardous materials, an enclosed glove box is available, which completely isolates the operator from all direct physical contact with the work material and tools.The enclosure can also maintain negative air pressure to ensure nothing can escape through tiny air leaks.
Mild Steel, Powder Coated Fume hoods have traditionally been manufactured using galvanized mild steel.The cost is low, but there will be corrosion problems over time, and the carbon footprint of the manufacturing process will be high.
Stainless steel typically used in radioactive applications or clean room or Atex environments
Polypropylene a modern building material that offers greater durability than traditional types.Production has a lower environmental impact than mild steel or stainless steel.
Phenolic resins (general applications)
Fiber Reinforced Plastic (FRP)
Polypropylene (best material for most applications)
Square corner stainless steel (durability and heat resistance)
Rounded stainless steel (easier to decontaminate, suitable for radiochemical and biohazard applications)
Cement board (rough use)
Most fume hoods are equipped with a mains powered control panel.Typically, they perform one or more of the following functions:
Low airflow warning
Warns that the opening in the front of the unit is too large ("high sash" alerts are due to sliding glass at the front of the unit being raised above a safe level, causing the wind speed to drop)
Allows exhaust fans to be turned on or off
Allows interior lights to be turned on or off
Certain extra functions can be added, for example a switch to turn the water washing system on or off.