Industrial centrifugal fans - Impeller between bearings
"EPDH" arrangement :
The single inlet fan is mounted between bearings on a passing shaft. The assembly is placed on an elevated structure made by concrete foundations. This is a non complex and very reliable arrangement. The bearing blocks are placed on pedestals of reduced height and the drive sits on a metal frame or directly over the concrete. The casing is anchored to the floor by means of its own frame.
"BD" arrangement :
Double inlet fan mounted between bearings on a passing shaft. Fan and drive are arranged on an integral supporting structure equipped with vibration isolator blocks. This is an optimum disposition for fans that must be installed on structures exposed to vibrations. The antivibration blocks decrease the amplitude of the dynamic forces caused by the rotation.
The double inlet fan is furnished with an integral frame that gives stiffness to the motor-fan assembly. This frame is anchored to a concrete foundation structure in which is lodged the lower part of the fan casing.