EXPERIMENTAL STUDY ON THE EXCITING FORCE OF FANS FOR BUILDING EQUIPMENT

Abstract

When constructing buildings where severe room environment (especially sound and vibration) must be met as in factories turning out high-tech products like LSI or concert halls, studios and hotels, it is necessary to estimate and countermeasure relating to noise and vibration from mechanical equipment needed in such buildings. To do so, it is basically necessary to make quantitative determinations of the exciting force of mechanical equipment. An experimental study was conducted, directly measuring via force guages the exciting force of a fan installed on a foundation which can be considered a rigid body. As a result, the exciting force of a fan in operation relative to shaft revolutions is underestimated, when determined from rotor balance quality Q. Our results indicate that better matching can be achieved by estimating lumped unbalance (m'r)_s from total mass of the fan. We propose the practical methods for estimating the exciting force frequency characteristics of fans from total mass and it's shaft revolutions.