Laboratory ventilation system

2022-12-30

Fume Hood Design Principles

1. According to the structural characteristics of the building, set up an air shaft nearby, divide the exhaust and make-up air systems, and make the piping system "short, flat, smooth, and straight" to reduce system resistance and system noise;

2. The air exhaust and supplementary air system achieves a balance of air volume, maintains a negative pressure of -5Pa—-10Pa in the room, prevents harmful gases from overflowing, and ensures the physical and mental health of experimenters;

3. Make up cold air in summer and warm air in winter to ensure the comfort of indoor temperature and humidity;

4. Adopt intelligent frequency conversion control system to achieve the purpose of convenient operation, energy saving and noise reduction;

5. Considering various factors comprehensively, adopt a mature process with less investment, stable operation, low operating cost and good operating effect;

6. The selected process must meet the site conditions, the layout is simple, compact, less land occupation, and convenient for production operation and maintenance;

7. Non-standard equipment should comply with relevant national or industry standards, and ensure stable performance and beautiful appearance;

8. Fully consider noise, odor, etc. in the design to prevent secondary pollution and not cause new pollution to the surrounding environment;

9. The treatment facilities have impact load capacity to ensure that the waste gas is discharged up to the standard.

Ventilation system control method

1. Constant air volume system control

(1) The system adopts static pressure sensing automatic frequency conversion control (or PLC programming control), and the static pressure sensing automatic frequency conversion control can change the sensed static pressure into 0-10v electrical signal input according to the number of ventilation equipment. The frequency converter automatically adjusts the frequency of the fan, so that the exhaust air volume of the fan matches the actual required exhaust air volume, so as to ensure the exhaust effect and achieve the effect of energy saving and noise reduction;

(2) Each fume hood is equipped with an electronic air volume control valve, and its control switch is linked with the frequency conversion control system and the fan, which can realize the control of single or multiple ventilation equipment under different working conditions. The air volume control valve adopts an electronic air volume control valve with digital display and adjustable angle, and has a memory function (that is, it can remember the angle of this adjustment, and it will still be adjusted to the designed angle when it is opened next time).

(3) The air valve of the system and the fan are interlocked as a whole to realize the orderly flow of airflow, balance the air volume of the system, and prevent the airflow from being reversed and reversed.

laboratory ventilation system - 1

2. VAV system control

(1) The system adopts static pressure sensing automatic frequency conversion control, which can change the sensed static pressure into a 0-10v electrical signal input to the frequency converter to automatically adjust the fan according to the number of ventilating equipment turned on. Frequency, so that the exhaust air volume of the fan matches the actual required exhaust air volume, so as to ensure the exhaust effect and achieve the effect of energy saving and noise saving;

(2) Each fume hood is equipped with a Venturi variable air volume air valve, and its control switch is linked with the frequency conversion control system and the fan, which can realize the control of single or multiple ventilation equipment under different working conditions. The variable air volume regulating valve adopts a venturi damper with digital display and adjustable angle, and has a memory function (that is, it can remember the angle of this adjustment, and it will still be adjusted to the designed angle when it is opened next time).

(3) The air valve of the system and the fan are interlocked as a whole to realize the orderly flow of airflow, balance the air volume of the system, and prevent the airflow from being reversed and reversed.

The laboratory ventilation system is one of the systems with the largest scale and wide influence in the whole laboratory design and construction process. Whether the ventilation system is perfect or not will directly have an important impact on the laboratory environment, the health of experimenters, and the operation and maintenance of experimental equipment.

Problems such as excessive negative pressure in the laboratory, gas leakage in the fume hood, and laboratory noise have always been difficult problems for laboratory staff. These problems have caused serious physical and psychological harm to the personnel who have been working in the laboratory for a long time, and even the management and logistics personnel working around the laboratory.

A scientific and reasonable ventilation system requires good ventilation effect, low noise, easy operation, energy saving, and even requires indoor pressure difference and temperature and humidity to maintain human comfort.

laboratory ventilation system - 2