Use and maintenance of fume hoods
The materials and gases used in the laboratory are harmful, so the use of the fume hood is very important in the experiment, but the fume hood also has a service life, and it is easy to fail if it is not properly maintained. Xiaobao takes you to understand the use and maintenance of the fume hood.
First, the common failure of the fume hood
1, when the ventilator and the ventilator matching fan does not work, you can check the following points:
(1) Check whether the resistance value of the motor coil matches the marked power.
(2) Check whether there is three-phase power output at the output end of the total power supply and frequency converter, and whether the wires along the line are damaged.
2. When the exhaust efficiency of the fume hood is reduced, the following points can be investigated:
(1) Whether the motor runs in reverse.
(2) Check whether there are cracks and air leakage at the joints of the working pipeline.
(3) Check whether the fan is affected by the phase adjustment or lack of phase of the total power supply.
Two, ventilation counter panel maintenance
1. Although the ventilation counter surface can withstand high temperature, it is not recommended to have direct contact with open flame and high temperature for a long time. When using electric furnace, it is necessary to add asbestos pad or triangular support for heat insulation.
2, although the ventilation counter surface has good corrosion resistance to various chemicals, long-term exposure to corrosive chemicals may also have some effects, so it is recommended that if there are chemicals dripping on the table, it should be removed as soon as possible.
Third, the use and maintenance of the fume hood
1. The fume hood should not be used as a storage cabinet, and the experimental device should not block the exhaust slit.
2, indoor air temperature between -5 ° C to +40 ° C, the 24-hour average does not exceed +25 ° C.
3. When using the fume hood, avoid interference with the countercurrent wind direction caused by personnel walking around.
4, the inside of the hood should always keep the inner surface of the cabinet clean and sealed, if there is damage, it must be repaired in time.
5, the laboratory does not use the fume hood should also be often ventilated, which is beneficial to the health of the experimenter.
6, every once in a while, the fume hood must be measured and adjusted. Make the fume hood operate as designed.
7. The temperature in the fume hood, such as the electric furnace with large wattage, should be padded with a pad plate, and should not be stored and opened for a long time, so as not to affect the use of the fume hood.
8, after the completion of the experiment, the fan should not be turned off immediately, and must be turned off after 3 to 5 minutes. Fans, air ducts and related accessories should be regularly repaired.
9. When using the fume hood, make up the air for 10 minutes every 2 hours. If the use time is more than 5 hours, the Windows should be opened to avoid negative pressure in the room.
10. During the experiment, the experimental device that produces harmful substances should be placed in the place where the operating mouth of the inner cabinet of the fume hood is greater than 150MM to prevent the overflow of harmful substances.