What design details should be considered when selecting a low-noise axial fan?

What design details should be considered when selecting a low-noise axial fan?

Selecting the Right Low-Noise Axial Fan: When the pressure coefficient of the rear impeller of a standard low-noise axial fan falls below a certain value at a given speed, the impeller diameter increases and the output rises; the opposite is true for the front impeller. In high-temperature, dusty environments, the protection and cooling of the motor and bearings must also be considered in terms of transmission methods. Selecting the Dimensions of a Low-Noise Axial Fan: The dimensions of the housing should be minimized as much as possible. For low-noise axial fans, a short housing can be selected; low-specific-speed low-noise axial fans typically use standard housings. To reduce the size of the volute, the outlet velocity may be higher than the inlet velocity of the low-noise axial fan; to increase static pressure, an outlet diffuser should be selected. Selection of the outlet angle for low-noise axial fan blades: The outlet angle of the blades is one of the key parameters that must be selected during design. For ease of use, blades are classified into the following categories: backward-curved blades (pump type), backward-curved circular blades, backward-curved straight blades, and backward-curved aerofoil blades; radial outlet blades and radial straight blades; forward-curved blades, and strongly forward-curved blades (multi-blade). Selecting the Number of Blades for Low-Noise Axial Flow Fans: In centrifugal fans, increasing the number of blades reduces the effect of relative vortices (i.e., increases the k-value), thereby increasing the theoretical pressure of the impeller. However, increasing the number of blades reduces the competition within the propeller passage, causing the fan’s actual pressure to decrease and energy consumption to increase. Therefore, each propeller type has multiple blade configurations. The specific determination of the number of blades may depend on the designer’s experience. Selection of the Total Pressure Coefficient ψ for Low-Noise Axial-Flow Fans: When designing a low-noise axial-flow fan, the actual pressure is always specified in advance. At this stage, the total pressure coefficient ψ must be selected based on t and the approximate selection criteria for the total pressure coefficient. The impeller is the part of the fan that transfers energy to the gas, and its design has a significant impact on the fan’s performance. Correctly determining the main structure of the propeller plays a crucial role in the fan’s performance parameters. This includes the primary technical blade design for low-noise axial fans. A key aspect of blade design is the method for determining the blade exit angle β2.