| 摘要 |
PURPOSE: To provide an air flow sensor for a mechanism including a centrifugal blower. CONSTITUTION: A centrifugal blower 20 includes an integral air flow measuring device 30 and a fan provided with an inlet cone 26 having a bosh-shaped inlet for receiving air and a bosh-shaped outlet for feeding air into a rotary fan wheel 24. The cone has a throat having a minimum diameter, and a hole communicated with a manometer 30 regulated in the throat. The hole of the cone surface near the bosh-shaped inlet is connected to the manometer, and pressure comparison between the surface of the fan and the narrowest portion of the throat is provided. A controller 32 monitors pressure difference, calculates a flow rate based on a characteristic concerning the cone, and the speed of the fan is adjusted to maintain a desired air flow. |
