Publish Time: 2022-04-18 Origin: Site
The main function of the fume hood in the laboratory is to prevent the diffusion of flammable and explosive substances in the laboratory, and to prevent the odor from being generated in the operation of the fume hood in the laboratory.
Fume hood is an essential kind of laboratory furniture. It has the effect of ventilation and ventilation in the laboratory.
In order to prevent laboratory staff from inhaling or swallowing some toxic, sickening or unidentified chemicals and organisms, the laboratory shall be well ventilated. In order to prevent the absorption of some vapors, gases and particles (smoke, soot, dust and suspension), pollutants must be removed by means of fume hood, ventilation hood or local ventilation.
Fume hood is the most commonly used local exhaust equipment in the laboratory. It has a wide variety. Due to its different structure and use conditions, its exhaust effect is also different. The good performance of the fume hood mainly depends on the speed of air moving through the fume hood.
The structure of the fume hood is up and down, and there is an exhaust hole on the top, which can be installed with a fan.
The upper cabinet has a deflector, circuit control, touch switch, power socket, etc. the perspective window adopts toughened glass and can move left and right or up and down. For human operation.
The lower cabinet adopts the style of experimental side table, with a table top and a cabinet body below. Small water cups and taps can be installed on the table.
The material of the fume hood consists of a variety of, all steel, steel wood, all wood, aluminum wood, plastic steel, PVC structure, etc. the table top is the place where the operator is in direct contact, which is composed of solid core physical and chemical board, stainless steel board, PVC, ceramics and other materials.
Old style fume hoods are mostly made of wood, but modern ones are mostly made of steel coated with epoxy resin. Common cabinets are 1000, 1200, 1500, 1800 and 2000 mm wide, 700-900 mm deep and 1900-2400 mm high. It can be used by 1-3 people at the same time. The fume hood is generally installed against the wall.
The front middle is a transparent door (mostly glass) that can move up and down, and the opening height is generally 100-600mm. Behind the door is the working face for the experiment. There are connections required for the experiment, such as water pipes, sewers, power supplies, vacuum pumps, gas pipelines, etc., and there are lights with protective covers on it. After the air is pumped out by the exhaust fan at the front and upper part of the cabinet, it is either led elsewhere through the pipeline (called full ventilation), or recycled after filtration (called ductless ventilation).
Most fume hoods will give an alarm when the exhaust volume is too small and the front glass door is opened too large to remind the operator that the wind speed at the operation port should not be less than 0.5m/s after the glass door is opened, and the speed of the internal exhaust fan and the lamp can be adjusted by switches.
When in use, people stand or sit in front of the cabinet, lower the glass door as far as possible, and extend their hands under the door into the cabinet for experiments. Since the exhaust fan exhausts air inward through the open door, harmful gases will not overflow in large quantities under normal circumstances.