Views: 0 Author: Site Editor Publish Time: 2022-04-20 Origin: Site
It is divided into three types: upper exhaust type, lower exhaust type and upper and lower exhaust type. In order to ensure the uniform wind speed in the working area, the fume hood in the cold process should use the lower exhaust type, and the fume hood in the hot process should use the upper exhaust type. The change of the internal calorific value adjusts the ratio of the upper and lower exhaust air volume, so as to obtain a uniform wind speed.
Full-exhaust fume hood: The indoor air is circulated in the cabinet and then discharged to the outside, which is called a full-exhaust fume hood, which is a very widely used type.
Supplementary air fume hood: When the fume hood is installed in a room with heating or temperature and humidity control requirements, in order to save heating and air conditioning energy consumption, the supplementary air is taken from the outside and circulated in the cabinet and then discharged to the outside, which is called supplementary air. fume hood.
Variable air volume fume hood: The ordinary constant air volume system needs to manually adjust the air valve of the fixed blade, adjust the exhaust air volume of the fume hood, and achieve the desired surface wind speed when the valve is adjusted to a certain angle. Variable air volume control is to change the air volume to a given surface wind speed by adjusting the sensor of the valve. Of course, the standard type has low cost and high variable air volume cost, and is suitable for occasions requiring high precision.
It can be divided into integral lower open type, floor-standing type, double-sided type, three-sided glass type, desktop type, conjoined type, and those designed according to the needs of different experiments for radioactive experiments, synthesis experiments, and perchloric acid experiments. dedicated fume hood.
The fume hood can be divided into integral lower open type, floor type, double-sided type, three-sided glass type, desktop type, conjoined type and designed according to the needs of different experiments for radioactive experiments and synthetic experiments. , a special fume hood for perchloric acid experiments.
The use of fume hoods in the laboratory is to ensure the safety of users and prevent pollution to the surrounding environment. These security are mainly reflected in:
1. The single-slot exhaust structure is adopted to effectively discharge harmful gases.
2. The streamlined handle, there is a gap between the handle and the glass, because the flow of air on the table is rotating, which ensures effective air intake from the surface.
3. Set the window anti-drop pin, in case the wire rope falls off the glass window and accidentally falls, the anti-drop pin will catch it to prevent people from being hurt.
4. The glass window is made of tempered glass. Even if the glass is accidentally damaged or exploded, there will be no accident.
5. Ventilation holes are set on the upper part of the fume hood, even if the glass window is closed, air can enter to avoid greater negative pressure.
6. The fume hood shell is made of metal material, which is fireproof and non-combustible. The inner cavity is made of flame-retardant or non-combustible materials such as anti-folding special board and stainless steel plate, and the table top is made of solid-core physical and chemical board or stainless steel plate that is resistant to acid and alkali, heat resistance and flame retardant.
7. The effective height of the glass window is 800mm, the inner cavity is 1200mm, and the height of the table is 800mm. It is ergonomic, easy to operate, has a large space for use, and improves safety.
8. The water nozzle and gas nozzle are equipped with remote operation handles outside the cabinet, which is more convenient and safe than direct manual operation.
