Laboratory ventilation sytstem is an integral part of laboratory design.Unlike biological safety cabinet and clean bench! Chemical fume hood in order to make the laboratory staff not to inhale into some unknown toxic chemicals particles and organisms.In laboratory should have good ventilation to prevent the income of some steam, gas and particles (smoke, soot, dust, and air suspensions), the pollutant must be removed by means of a fume hood, ventilator hood or local ventilation.structure.
Fume hood shelled by a variety of materials, all steel, steel&wood, aluminum&wood, plastic steel,PVC Operating desktop is made of solide phsiochemical plate, stainless steel plate, PVC, ceramic material and so on.
The front center is a transparent door that can be moved up and down (mostly glass). The opening height is usually 100-600 mm. Behind the glass is the working desktop, there is the connection of water pipe, sewer, power supply, vacuum pump, gas pipeline and so on, and above is lamp with protective cover.The air is removed by a fan in front of the inside cabinet, or it is piped to another place (known as full ventilation), or re-circulated through filtration (to become unpipeventilated).
Biosafety hoods types:
|Traditionl hood:||Designed for general protection, and have a constant air volume(CAV).These types of hoods can be installed with or without a bypass provision.|
|Variable air volume hood:||Which can vary the air volume exhausted through the hood dewpending upon sash position.|
|Benchtop fume hoods:||Smaller, economical fume hoods that are ideal for small facilities,or for facilities that require lots of fume hoods, such as schools,colleges, and universities.|
|Constant volume auxiliary air hood||Allows outside air - also called"auxiliary"air,to come in diredtly in front the sash, but outside the hood|
|Ductless fume hoods||Have conventional design but self-contained to re-circulate air into the lab after filtration occurs.|
|Walk-in hoods:||Which allow for large pieces of furniture;"snorkls,"which are somewhat mobile and allow the worker to place it over the area needing ventilation.|
A type of constant volume air hood that is desighed for ease of cleaning
|Other specialized type:||Include distilation hoods, canopy hoods, downdraft hoods, and elephant trunks.|
Biologicl hood sketch map: