Venturi valve: The core guarantee for safety and energy saving in fume hoods
Working Principle of Venturi Valves in Fume Hoods Venturi valves are designed based on the Venturi effect. Through a unique throat structure and differential pressure sensing technology, they achieve precise control of the exhaust volume of the fume hood. The specific working process is as follows: Negative Pressure Monitoring: A differential pressure sensor is installed inside the fume hood to monitor the air pressure difference between the inside of the hood and the room in real time (industry standards require the hood to maintain a negative pressure of -10~-30Pa). When the pressure difference changes due to factors such as door opening/closing or gas generation from material reactions, the sensor immediately transmits a signal to the controller. Adaptive Flow Regulation: After receiving the signal, the controller drives the valve core of the Venturi valve to move rapidly, adjusting the airflow speed by changing the throat cross-sectional area. When the hood door is open, the valve core automatically opens wider, increasing the exhaust volume to maintain negative pressure; when the hood door is closed or operation stops, the valve core closes, reducing the exhaust volume to avoid excessive exhaust and energy waste. Stable Output Guarantee: The throat design of the Venturi valve ensures a stable jet flow, unaffected by duct pressure fluctuations. Even with changes in duct resistance, the exhaust volume deviation can be controlled within ±5%. Within the fume hood, ensuring that contaminants are always confined inside.
Core Advantages of Venturi Valves in Fume Hoods
1. Enhanced Safety Protection: Preventing Contaminant Leakage
Traditional butterfly valves and ball valves typically have a response time of 2-3 seconds, while Venturi valves can respond in 0.1-0.3 seconds, instantly handling sudden situations such as rapid door opening and closing, preventing harmful gases from escaping due to momentary negative pressure imbalance. Simultaneously, its high-precision flow control ensures that the fume hood surface velocity remains stable at 0.4-0.6 m/s (international safety standard range), maintaining consistent protection whether operating as a single unit or in parallel with multiple units. This makes it suitable for scenarios with stringent pollution control requirements, such as chemical analysis, biopharmaceuticals, and semiconductor manufacturing.
2. Significant Energy Saving: Reducing Operating Costs
Laboratory ventilation systems are major energy consumers. Traditional valves often suffer from excessive exhaust due to their "constant airflow" design—maintaining maximum airflow even when the fume hood is not in use. Venturi valves employ Variable Air Volume (VAV) control, dynamically adjusting the exhaust volume based on actual usage conditions. When the cabinet door is closed, the airflow can drop to 30%~50% of the rated value, resulting in annual energy savings of several thousand kilowatt-hours per unit. For example, in a laboratory with 100 fume hoods, using Venturi valves can save hundreds of thousands of yuan in electricity costs annually, while simultaneously reducing air conditioning load, achieving a "win-win situation of safety and energy saving."
3. Convenient Installation and Maintenance: High Adaptability. Venturi valves have a compact structure, requiring no complex piping modifications. They can directly replace traditional valves and are compatible with various fume hood sizes (from small benchtop cabinets to large floor-standing cabinets). They have no easily worn parts internally, resulting in a long service life. Routine maintenance only requires periodic cleaning of the sensors and throat, reducing operating costs. Furthermore, some high-end models support remote monitoring and data upload, recording parameters such as airflow and differential pressure in real time, facilitating compliance audits and system optimization by management personnel.
Conclusion
The Venturi valve enables fume hoods to operate with an "active adaptation" logic, balancing safety and energy conservation. It is a core component in industrial and scientific research applications, driving the industry towards "safe, efficient, and green" development.