As a commonly used fluid machinery in the industrial field, centrifugal blowers rely on unique power transmission and gas compression mechanisms for their efficient and stable operation. This article will systematically analyze the core mechanism of its working principle and transmission mode.
1、 Principle of centrifugal force boosting
The core working principle of a centrifugal blower originates from Newton's second law and the laws of fluid mechanics. When the motor drives the spindle to rotate, the impeller (usually a rear curved blade) rotates at a high speed of 1450-3000rpm, and the gas between the blades is subjected to centrifugal force and thrown towards the outer edge (with a linear velocity of up to 30-50m/s). By converting the kinetic energy of the impeller and using the volute guide structure, the gas pressure is increased from atmospheric pressure at the inlet to 0.2-0.8 MPa. The magnitude of pressure increase is proportional to the square of the impeller diameter (D 2) and the cubic speed (N 3), which determines its high efficiency characteristics.
2、 Transmission System Analysis
1. Direct drive
The direct drive structure directly connects the motor shaft to the main shaft of the blower, eliminating intermediate components such as gearboxes. This method has a transmission efficiency of up to 95% -98%, and the power range is usually between 7.5-200kW. Its advantage lies in the absence of gear vibration interference, simple maintenance, but limited speed range.
2. Gear transmission
The dual support gearbox (module 2-5) has a transmission ratio range of 1:1.5-1:3, which can increase the motor speed from 5-100kW to the required working condition of the impeller. Three speed transmission is achieved through planetary gear sets, with a total transmission efficiency of about 90% -93%, suitable for large equipment (flow rate>100m 3/min).
3. Belt drive
The V-belt drive is suitable for small and medium-sized units, with a transmission power range of 2-50kW. Tension wheel adjustment can achieve ± 10% speed adjustment, but the energy consumption is 3% -5% higher than direct drive, and the belt needs to be replaced regularly.
Modern centrifugal blowers often adopt an integrated cast aluminum alloy structure with a main shaft and impeller, combined with a reinforced gear lubrication system (SAE 80W-90 lubricating oil), vibration sensors, and variable frequency controllers to ensure long-term stable operation in an environment of -20 ℃ to 40 ℃, and the overall efficiency of the machine exceeds 80%.
