Laboratory Fume Hood: Core Equipment for Safety and Efficiency
Working Principle
Based on aerodynamics, it achieves directional exhaust of harmful substances through negative pressure design: when the sash is opened to 200-300mm, an "air curtain" is formed to prevent gas leakage; the centrifugal fan quickly extracts harmful gases. High-end models are equipped with deflector plates and sensors to optimize air flow, monitor wind speed in real time, and trigger alarms if abnormalities occur.
Selection Key Points
Type: Ducted type (for high-concentration harmful gases, requiring connection to centralized exhaust systems) and ductless type (for low-concentration pollutants, using activated carbon adsorption); materials include all-steel (for chemical experiments), PP (polypropylene, for strong corrosion environments), and stainless steel (for biological/clean laboratories).
Wind Speed: 0.3-0.5m/s for routine experiments, and 0.5-0.8m/s for highly toxic/volatile gases.
Additional Functions: Explosion-proof, high-temperature resistance, built-in water nozzle and sink, etc., to be selected according to actual needs.
Usage Specifications
Check wind speed, fan operation, and sash sealing before operation;
During experiments, do not extend the face into the hood, conduct all operations inside the hood, and do not open the sash beyond the specified height;
Do not place irrelevant items, use the hood as a storage cabinet, or arbitrarily turn off the fan/reduce wind speed; wear protective equipment for hazardous experiments;
In case of emergency, close the sash, keep the fan running, evacuate immediately, and activate the emergency response plan.
Maintenance
Clean the cabinet daily to remove reagent residues;
Inspect the fan and pipelines every 3-6 months; replace the activated carbon filter regularly for ductless models;
Calibrate sensors and control equipment annually, and entrust professional institutions to conduct comprehensive inspections (in compliance with GB/T 27476-2018).