The choice of laboratory furniture should consider improving work efficiency, working convenience, and reducing the risk and injury of occupational diseases. Regardless of whether the laboratory chooses steel-wood structure or all-steel structure furniture, it must be reasonably selected and matched according to the overall requirements of the laboratory. Mainly from: test bench specifications, test bench surface material, test bench cabinet material, test bench water, electricity, gas integration functions, etc.; and the fume hood, as the most important laboratory in the laboratory, is also one of the furniture with high hazard coefficients. First, you must be more cautious in the selection process. The following will systematically explain the function and selection of the fume hood.

Selection of fume hood and precautions for use

In chemical experiments, various harmful gases, odors, moisture, and flammable, explosive, and corrosive substances are often produced; in recent years, in order to protect the safety of experimental technicians and improve the experimental environment, many of them were originally on the experimental bench. The experiments carried out are gradually transferred to the fume hood to prevent the pollutants in the experiment from spreading to the laboratory. It is the best way to put the experiments that constitute the pollution source into the fume hood; the function of the fume hood is mainly to isolate the hazard source and the outside. Row processing.

With the development of economy and the requirements of personnel on the working environment, generally larger areas of experiments are equipped with central air-conditioning systems. Some laboratory construction units consider factors such as loss of cooling capacity and increased energy consumption, and prefer to choose supplementary ventilation. Cabinet: The feature of the supplemental air fume hood is that it is equipped with an air supply port on the top of the front, which sends a certain proportion of air into the fume hood from the outside. When the cabinet door is opened, the air flow forms an air curtain at the operation port to block harmful The gas overflows, and only a certain proportion of the remaining air is replenished indoors.

Although the supplementary air fume hood can have advantages in energy saving, it also has the following problems:

1. Since the supplemental air fume hood adds an air supply system, the initial investment increases, and the required power consumption also increases, that is, the operating cost increases. Therefore, when the supplementary air fume hood is used, the overall system should be The payback period is evaluated.

2. The energy saving of the supplementary air fume hood is attributed to the use of outdoor air that is not heated or cooled, which will affect the indoor air temperature and humidity conditions, especially in the northern winter, the outdoor temperature is very low, which may bring discomfort to the human body The operator’s safety is reduced, and the operation results of many supplementary air fume hoods are not energy-saving, and some systems even consume more energy than traditional fume hoods.

3. The air supply speed of the air supply outlet of the supplementary air fume hood is not conducive to control, and it is easy to produce a Venturi effect, which causes the toxic and harmful gases in the cabinet to overflow and pollute the air in the test area, which has certain potential hazards to the experimental operators.

Therefore, in the process of laboratory design and construction, in addition to considering comfortable air conditioning and fume hood exhaust, an additional set of fresh air system should be configured to meet the requirements of laboratory personnel for fresh air and fume hood ventilation requirements. The fresh air system and the exhaust system can be linked to control. In the long run, it is more conducive to the control of the investment cost of the laboratory to abandon the supplementary air fume hood and choose to add a fresh air system.