The importance of Fume Hood in laboratory construction
Using the Fume Hood is the biggest purpose discharge harmful gases generated in the experiment, protect the health of the researchers, that is to say, want to have a high security and excellent operability, which requires the Fume Hood should have the following features:
(1) release function: it shall have the means to absorb the harmful gas from the Fume Hood inside the cabinet, so as to eliminate the outdoor mechanism after dilution.
(2) no reverse flow function: the air flow generated by the exhaust fan in the Fume Hood shall be the function of the harmful air flow from the inside of the Fume Hood into the interior. In order to ensure the implementation of this function, a hood and a fan with a single pipe connection is the best way, cannot use a single pipe connection, also only can be provided the same room and even, fan installed at the end of the pipe as far as possible (or roof).
(3) isolation function: in front of the Fume Hood, the ventilation cabinet shall be separated by an unsliding glass window.
(4) supplementary function: a passage or an alternative device that takes air out of a Fume Hood when discharging harmful gases.
(5) control the wind speed function: to prevent the harmful gas escaping from the ventilation cabinet, it needs to have a certain speed of inhalation. The factors that determine the intake speed of air inlet are: the heat and the relationship with the number of ventilation. The main one is the content of the experiment and the nature of the harm. Generally, it is stated that the non-toxic pollutants are 0.25%-0.38m/s, toxic or dangerous substances are 0.4-0.5 m/s, and the poisonous or small amount of radioactivity is 0.5-0.6 m/s, the gas is 0.5m/s and the particle is 1m/s. In order to ensure the wind speed, the exhaust fan should have the necessary static pressure, namely the friction resistance of air through the ventilation ducts. Determine the wind speed must also pay attention to the noise problem, through the air in the pipe flow is limited to 7-10 m, more than 10 m will produce noise, usually laboratory (indoor background noise level) noise limit is 70 dba, increase the pipeline laying area can reduce wind speed, also reduce noise, considering the funding and pipeline construction question, must choose carefully pipeline and exhaust fan power.
(6) resistance to heat and acid and alkali corrosion: in the ventilation cabinet, some are reinstalled, and some experiments produce a large amount of toxic and harmful gases, such as acid and alkali, which are highly corrosive. The countertop of the Fume Hood, the lining board, the side board and the selected water mouth and the nozzle should have the anti-corrosion function. In the semiconductor industry or corrosive experiment the use of acid, nitric acid, hydrofluoric acid and other strong acids are also required to be used for the overall material of the fume cupboard must be alkali resistant, made of stainless steel or PVC materials.
The construction of modern biochemical laboratory is a comprehensive system project. In the equipment of all kinds of instruments and equipment and its supporting facilities at the same time, should not only consider the power supply, water supply, drainage, air supply and exhaust air purifying sewage, but also to the security of personnel, objects and surroundings, noise, smell, visual environment of comfort, the maneuverability of the equipment, functionality, and ease of processing. Therefore, the modern biochemistry laboratory must have the best design and high-quality equipment to satisfy.
The safety of the Fume Hood is required to guarantee a bit of property, because the safety of the laboratory and scientific researchers who have been used in the safe area of the Fume Hood is a catastrophic failure. In many surprises, the loss or damage caused by the lab caused by a failed Fume Hood or temporary collapse. The safety performance of Fume Hood is a design element that needs to be concerned.