Axial fans

Single and dual inlet centrifugal blowerswith forward curved bladesThe forward curved centrifugal impeller must always be operated insidea scroll housing.A dual inlet centrifugal blower shows the same behaviour as two singleinlet blowers operated in parallel: with size, speed and pressure beingidentical, double the air flow is achieved.Operating rangeMiddle part of air performance curve:– Maximum efficiency– Minimal noise– Higher performance density than with the backward curvedcentrifugal fanTo the right and the left of the middle part of the air performance curve:– Reduced efficiency– Increasing noiseThe optimum operating range of the fan is shaded in green in the curvegiven here.Noise / efficiency curve[Pa][%][dB(A)]optimum operating range00[m³/h]Dimensioning of the scrollThe dimensions of a typical scroll can be calculated with the followingformulae, subject to the impeller diameter D:CDB45˚45˚45˚JAK45˚E45˚26˚45˚FHGA = 1.062 · DB = 0.992 · DC = 0.922 · DD = 0.853 · DE = 0.784 · DF = 0.715 · DG = 0.646 · DH = 0.612 · DJ = 0.720 · DK = 0.689 · DR = 0.073 · DAdjusting the dimensions to diminished mounting spaces is possible.R404