R_O_M
Guest
The separator fan is a cross flow fan that runs at constant speed. A very high speed vortex operates inside of the cross flow fan drawing air in through the blades on the one side of the cut off plate and the throttling blade and exhausting it through the blades on another segment of the fan . You are right Dan in saying that the clearance of the throttling blade or cut off plate are critical in controlling the amount of air entering these types of fans and therefore the total fan flow. Air-con fans, such as in the Gleaners, are very different in operation. They are a squirrel cage or forward swept blade type centrifugal fan that draw their air into the centre of the fan impeller and exhausts it through the outer blades. They are not very fussy about clearances around them and between the impeller blades and the housing. As Dan says, get the blade direction wrong and you will really suffer! Increasing airflow through these fans needs increased RPM's. If you double the speed of almost all fan types you will get twice as much air, four times as much pressure and need eight times as much HP to drive it so even a very small increase in speed consumes a lot of HP. Rolf installed the relays under the cab near the fans with a very heavy power lead into the relays. This by passed the need to put high power through the cab switch. Opening up and enlarging the air hose sizes out of the fan box to the cab inlets also made a substantial difference. It sure needed it! Cheers!