Duct fans are widely used in industries such as industry and construction, but the noise problems generated during their operation often need to be solved. At present, common noise control technologies mainly start from the structural design of the duct fan itself, airflow optimization, and peripheral noise reduction measures. In the structural design of duct fans, the key is to reasonably design the shape of the impeller. Parameters such as the number of impeller blades, radius of curvature, and installation angle will directly affect the degree of turbulence and aerodynamic noise when the airflow passes through. For example, the use of backward-inclined blades can reduce the impact of airflow and the generation of vortices to a certain extent compared with forward-inclined blades, thereby reducing noise. At the same time, the dynamic balancing accuracy of the impeller is also very important. If the impeller has mass imbalance, it will generate large vibration noise when rotating at high speed. This situation can be effectively alleviated through fine dynamic balancing debugging.
Airflow optimization is also an important means of controlling noise. The unstable flow of airflow in the pipeline is one of the main reasons for noise, so it is very important to optimize the pipeline design to reduce airflow resistance and turbulence. Reasonable design of the cross-sectional area and direction of the pipeline to avoid sudden changes in diameter and sharp turns can make the airflow pass smoothly and reduce the noise caused by airflow impact and friction. In addition, setting guide devices at the inlet and outlet of the duct, such as guide vanes or trumpet-shaped inlets, can guide the airflow to enter and flow out of the duct fan evenly, reduce airflow separation and vortex formation, and thus reduce noise.
Peripheral noise reduction measures should not be ignored either. Soundproof cover is a commonly used peripheral noise reduction method. By setting a soundproof cover around the duct fan, the noise is enclosed in a certain space to prevent it from spreading to the outside. The soundproof cover is usually made of multi-layer sound insulation materials, such as soundproof panels, sound-absorbing cotton, etc., which can not only reflect noise but also absorb part of the sound energy, thereby achieving noise reduction effect. At the same time, elastic shock-absorbing devices, such as rubber shock-absorbing pads, spring shock absorbers, etc., are used at the connection between the duct fan and the pipeline to reduce the transmission of duct fan vibration through the pipeline and reduce solid-borne sound noise.
In practical applications, air volume and silent performance are often mutually restricted and need to be reasonably balanced. The size of the air volume directly affects the ventilation and heat dissipation effect of the duct fan, and increasing the air volume usually requires increasing the speed of the duct fan or increasing the impeller size, which in turn leads to a corresponding increase in noise. Therefore, it is necessary to comprehensively consider the needs of both in the design and selection stage. First, determine a reasonable air volume range based on actual ventilation needs to avoid blindly pursuing large air volume at the expense of silent performance. Under the premise of meeting the air volume requirements, select duct fan models and structural forms with lower noise.
Optimizing the operating parameters of duct fans is also an effective way to balance air volume and silent performance. By adjusting the speed of duct fans through variable frequency speed regulation technology and reducing the speed when the maximum air volume is not required, both energy consumption and noise can be reduced. For example, at night or in an environment with high noise requirements, the speed of duct fans can be appropriately reduced to reduce noise interference while ensuring basic ventilation needs. At the same time, the number of duct fans in operation should be reasonably set, and the number of running duct fans should be adjusted according to the actual load conditions to avoid a single duct fan running under high load and high noise conditions for a long time.
The optimized design of airflow organization also helps to balance the relationship between the two. By reasonably arranging ducts and air outlets and optimizing the distribution and flow path of airflow, the ventilation efficiency can be improved without increasing the air volume of duct fans, thereby reducing dependence on large air volume duct fans and reducing noise. For example, using uniform air supply ducts or reasonably setting up return air systems to make the airflow more evenly distributed in the space, avoiding local airflow dead corners or high-speed airflow areas, can not only ensure ventilation effects, but also reduce noise.
In addition, the impact of noise on air volume can also be reduced by adopting advanced noise reduction technologies and materials. For example, spraying a noise reduction coating on the surface of the duct fan impeller, which has sound absorption and damping characteristics, can reduce the aerodynamic noise generated when the impeller rotates, while not affecting the aerodynamic performance and air volume output of the impeller. For another example, using low-noise bearings instead of traditional bearings can reduce the noise generated by bearing friction and vibration, so that the duct fan can maintain the air volume while reducing the overall noise level. In short, balancing air volume and silent performance requires comprehensive consideration of multiple aspects such as duct fan design, parameter optimization, airflow organization, and noise reduction technology application, and reasonable adjustment and optimization according to specific usage scenarios and needs to achieve the best use effect.
