Cooling towers are used in many process applications in the petrochemical industry. Reliability of these towers is crucial. In many cases, redundant towers are installed to ensure a process will not have to be stopped due to a cooling tower failure. The most prevalent cause of cooling tower downtime is failure of the right angle gearbox or associated mechanical components, such as the driveshaft or disc couplings. Further, the elimination of these components reduces the losses in the drive system and offers the possibility for improved overall system efficiency. This paper describes new developments in motor technology which allow for the replacement of the high speed motor, driveshaft, couplings, and gearbox with a slow speed permanent magnet (PM) motor. A case study is presented with maintenance and efficiency improvement data provided.
