Views: 0 Author: Site Editor Publish Time: 2022-01-17 Origin: Site
Building a modern biochemical laboratory is a comprehensive system engineering. While equipping various instruments and equipment and supporting facilities, it is necessary to consider not only the requirements of power supply, water supply, drainage, air supply, exhaust air purification and sewage discharge, but also the safety of personnel, objects, and surrounding environment, noise, and odor , The comfort of the visual environment, the operability and functionality of the equipment, and the convenience of information processing. Therefore, the modern biochemical room must have good design and high-quality equipment to satisfy.
Among the modern equipment, there are central laboratory benches, side tables, medicine cabinets, utensil cabinets, gas cylinder cabinets, etc. Among them, the biochemical room equipment is responsible for very important functions and is an indispensable equipment. Therefore, choice is an important issue in construction, and sufficient attention must be paid.
The main function is the exhaust function. In the chemical room, various harmful gases, odors, moisture, and flammable, explosive, and corrosive substances are generated during the experiment operation. In order to protect the safety of users, prevent the experiment Pollutants diffuse, and they must be used near the pollution source. In the past, the number of units used was small, and they were only used in experiments that generate particularly harmful and dangerous gases and generate a lot of heat. Only responsible for the auxiliary functions of the experimental bench.
In recent years, considering the improvement of the experimental environment, the experiments carried out on the experimental bench have gradually been transferred to the inside, which requires that there should be functions suitable for the use of equipment. In particular, most new buildings require air conditioning, so the number of units to be used must be included in the air conditioning system plan in the preliminary design stage of the building. Because it occupies a very important position in the biochemical room, the number of units used has increased dramatically from the perspectives of improving the environment, improving labor and hygiene conditions, and improving work efficiency. Following this is the ventilation ducts, and piping, wiring, exhaust, etc. have become important issues in construction.
The main purpose of use is to discharge the harmful gases produced in the experiment and protect the health of the experimenters, that is to say, it must have a high degree of safety and superior operability, which requires the following functions:
(1) Releasing function: It should be equipped with a mechanism to absorb harmful gas generated inside by absorbing the gas outside the cabinet, dilute it and discharge it outside.
(2) Non-reverse flow function: it should have the function of preventing harmful gas from flowing back into the room from the inside by the airflow generated by the exhaust fan. In order to ensure the realization of this function, it is a good way to connect a fan to a fan with a single pipe. It cannot be connected by a single pipe, and it is limited to parallel connections in the same room on the same floor. The fan should be installed in the pipe as much as possible. At the end (or at the top of the layer).
(3) Isolation function: a non-sliding glass window should be used to separate the inside and the outside.
(4) Supplementary function: It should have a channel or alternative device for inhaling air from outside when discharging harmful gas.
(5) Wind speed control function: In order to prevent harmful gas from escaping inside, a certain suction speed is required. The factors that determine the intake speed of the intake air are: the heat generated by the experiment content and the relationship with the number of air changes. The main ones are the content of the experiment and the nature of the harmful substance. It is usually stipulated that the general non-toxic pollutant is 0.25-0.38m/s, the toxic or dangerous hazardous substance is 0.4-0.5 m/s, the highly toxic or has a small amount of radioactivity is 0.5-0.6m/s, and the gas is 0.5m/s, granular material is 1m/s.
In order to ensure such a wind speed, the exhaust fan should have the necessary static pressure, that is, the frictional resistance when the air passes through the ventilation duct. When determining the wind speed, you must also pay attention to the noise problem. When the air flows through the pipe, the limit is 7-10m. Noise will be generated if the air is over 10m. Normally (indoor background noise level) the noise limit value is 70dBA. Increasing the pipe cutting area will reduce the wind speed. It also reduces noise. Considering the cost and construction of the pipeline, the power of the pipeline and the exhaust fan must be carefully selected.
(6) Heat resistance and acid and alkali corrosion resistance: some electric furnaces must be installed inside, and some experiments produce a large amount of toxic and harmful gases such as acid and alkali, which are extremely corrosive. The countertop, lining board, side board and the selected water nozzle, gas nozzle, etc. should have anti-corrosion function. In the semiconductor industry or where strong acids such as sulfuric acid, nitric acid, and hydrofluoric acid are used in the semiconductor industry or corrosive experiments, the overall material must be acid-proof and must be made of stainless steel or PVC.
