Differences Between Forward-Curved and Backward-Curved Centrifugal Fans

Differences Between Forward-Curved and Backward-Curved Centrifugal Fans Forward-curved and backward-curved centrifugal fans primarily differ in their blade configurations. Typically, forward-curved types serve as supply fans, while backward-curved types function as exhaust fans. The distinction lies in the length of the blade path and the blade edge orientation. The blade is inclined forward relative to the blade axis. When the blade outlet angle exceeds 90 degrees, it is termed a forward-curved blade, primarily used for high-pressure applications. The backward-curved blade is not parallel to the blade axis, differing by several centimeters or millimeters in length from the blade edge. When the outlet angle is less than 90 degrees, the backward-curved impeller is also called a backward-curved impeller, primarily designed for medium-pressure applications. The differences are primarily reflected in the following three aspects. Difference 1: Static pressure head used to overcome system resistance is lower in forward-curved centrifugal fans than in backward-curved centrifugal fans. Backward-inclined centrifugal fans exhibit lower hydraulic pressure loss than forward-inclined fans due to their gradually widening flow channels. Consequently, the efficiency of forward-inclined centrifugal fans is lower than that of backward-inclined centrifugal fans. Difference 2: Power consumption. Forward-inclined centrifugal fans consume more electricity than backward-inclined centrifugal fans due to their lower efficiency. Difference 3: Noise. Forward-inclined centrifugal fans produce higher operational noise levels than backward-inclined centrifugal fans. Both forward-curved and backward-curved centrifugal fans possess distinct advantages and disadvantages, allowing selection based on specific requirements. During application, it is essential to leverage their strengths while mitigating weaknesses to maximize the immense functionality of centrifugal fans, enabling companies to create greater value.