| 摘要 |
A centrifugal fan (20) having an integral air flow measurement apparatus, the fan including an inlet cone (26) having a flared inlet (58) for receiving air and a flared outlet (60) for expelling air into the center of a rotating fan wheel (24). The cone (26) has a throat (72) having a minimum diameter, with apertures (76) defined within the throat (72) and in communication with a manometer (30). Apertures (78) in the face of the cone near the flared inlet (58) are connected to the manometer (30) to provide a pressure comparison between the face of the fan (20) and the narrowest portion of the throat (72). A controller monitors the pressure differential, calculates a flow rate based on known characteristics of the cone, and adjusts the fan speed to maintain the desired air flow. <IMAGE> |
