ADVANCED LOW NOISE AIR COOLING FANS

摘要

It has become apparent in the last two decades that the use of propeller fans in coolingtowers and condensers becomes more and more complicated. This is particularly true inhighly urbanized areas because of restrictions that have been set forth on noise levels bypublic authorities.Since the classic propeller-type fan for air cooling has high noise levels, this is a importantproblem. One way to reduce the noise levels is to operate the fan at a much lower duty pointthan for which it has been originally engineered. The consequence of applying this methodshows that a required cooling capacity can only be made by using more cooling fans withbigger cooling towers. Another method which is tried to solve the problem is to install soundattenuators. However sound attenuators (baffles) are poorly effective in an air coolinginstallation due to several reasons. As a well known principle, also in this case it turns outthat tackling the problem at the source is the most effective way of doing.