This product has obtained a patent: Patent for side air inlet noise reduction and silencing device of pressure-type axial flow local ventilator for underground coal mines (Patent Certificate No. 2583510).
 
FBD series flameproof press-fit axial flow local ventilator is characterized by new type, high efficiency, energy saving and low noise. Because the fan adopts internationally leading three-dimensional twisted, swept and orthogonal combination blades, the fan airflow is stable, vibration is weak, and it has high operating efficiency. The unique blade structure design also keeps the noise far below the national noise level. Within the standard, environmental pollution is greatly reduced.
 
At present, the domestically produced FBD series flameproof press-fit axial flow local ventilators often have noise levels of 100-120 decibels in underground environments, greatly exceeding the national noise standards and becoming one of the main noise sources in mines. The physical and mental health of coal miners who work in mines for a long time has a certain impact, and it also affects the further improvement of production efficiency.
 
Our company, together with scientific research institutions from colleges and universities such as Xi'an Jiaotong University and Dahl Fluid Research Institute, went deep into the use site of local fans in coal mines, conducted on-site analysis of the noise generated by the fans, communicated with ventilation equipment management operators, and confirmed that the current local fans were used. The loud fan noise mainly comes from the radiated noise caused by the friction noise of the air at the air inlet. A variety of noise reduction design solutions have been proposed for this situation. After long-term and large-scale repeated testing and verification, an effective and cost-effective noise reduction solution has been finally determined. Solution - The air inlet adopts a side air inlet structure design.
 
The original fan inlet air flow direction is parallel to the direction of the fan rotation axis, and the inlet noise is reduced through flow collection and rectification. Due to the design limitations of this structure, the reflected noise is large and the noise reduction effect is not obvious, which has a great impact on the use environment.
 
The side air inlet design concept breaks through the existing fan design ideas, making the air flow along the curve of the streamlined guide cap, merge with the side air flow, and press into the noise reduction and silencer device from the circumferential direction, passing through the collector tube and the streamlined guide cap (inner Containing high-performance silencing cotton), part of the reflected noise is inhaled through the diversion cap and diversion silencing cone, and the air flow is directed out in a direction parallel to the rotation axis of the fan. After testing and comparison, after the original collector assembly was replaced with our company's first and uniquely designed side-inlet noise reduction and silencing device, the noise can be reduced by more than 15 decibels.



Coupled with the optimization of the internal structure of the fan, the friction and radiation noise of the air flow in the casing is further controlled and reduced. After five years of successful development, the FBD series local ventilator adopts counter-rotating direct-coupled transmission, which reduces the guide vane device. While increasing the fan pressure, it also straightens the direction of air flow; reduces the friction sound of the air; internal structure The optimization controls the friction radiation noise inside the machine; the first unique structural design - the air inlet adopts the use of a side air inlet silencer device that has been accepted by the national patent, changing the traditional axial air inlet method and effectively reducing the inlet noise; streamlined silencer The cap is jointly designed by our company, Xi'an Jiaotong University and Dahl Fluid Research Institute and processed with special molds, which not only improves efficiency but also reduces noise. The overall operating noise can be controlled below 80 decibels. The ultra-low noise has a significant effect on changing the noise environment of the underground constrained space.
 
The use of ultra-low noise FBD mine explosion-proof press-in axial flow local ventilator can effectively improve the working environment of coal miners underground.