The impeller is composed by blades, front plate, rear plate, and the wheel hub.The blades are welded on two sides plate; rear plate is riveted with wheel hub by rivet;
the whole impeller is fixed on the crankshaft by wheel hub.
Some high pressure fan impeller is casted entirely.For now, the direction of fan impeller front plate tends to be tapered or conical curved, which is consistent with the direction of air flow, to help reduce obstruction and improve fan efficiency.
Fan impeller is the most important components in blower. In particular, the blade form in impeller has the biggest effect on the blower performance.
The blower performance and efficiency mainly depend on fan impeller, but the shape and size of casing, the shape of the air inlet, etc., also have important influence.
The role of the casing is to collect air from the impeller, and make the air flow to air outlet, at the same time, to make the air dynamic pressure from the impeller convert to static pressure.
|different direction of outlet|
Air flow has the least resistance in spiral shape casing. The cross section of spiral casing expands gradually along the impeller rotation direction, and reach the maximum in air oulet.
In order to meet working place requirements, one model blower can have different outlet shapes, with the different direction of rotation and angle.
For example, from the motor side, if the fan impeller rotates clockwise,this fan is right-turn blower; on the contrary, this fan is left-turn blower. Right is the basic rotation direction.
3. Supporting and Drive Modes
Generally, the supporting is made from cast iron or carbon steel.
|different drive modes of centrifugal fan|
The driving modes include A, B, C, D, E, F.
A--Cantilever supporting, and motor drive directly
B--Cantilever supporting, and belt pully drive
C--Cantilever supporting, and belt drive
D--Cantilever supporting, and coupling drive
E--Double supporting, and belt drive