17-25: Using Direct Drive Technology for Improved Reliability and Efficiency

This paper discusses the development of low speed, permanent magnet motors and how they can be used in direct-drive applications to eliminate the gearbox, NEMA motor, driveshaft, and disc couplings from field erect cooling tower designs. Improved reliability of cooling tower fan drives is now possible due to advancements in motor technology as evidenced over the last 9 years. Case studies are presented where cooling towers have been retrofitted. Design considerations, best practices, performance data, maintenance, air flow considerations and efficiency comparisons will be discussed.