A Variable Frequency AC Blower Drive Installation for Efficient and Accurate Control of Glass Tempering

Today´s escalating energy costs often justify modifying existing industrial equipment to improve operating efficiency. One common instance occurs In air handling, where vane or damper controls are being replaced by variable speed blower operation. AC variable frequency drives offer the advantages of utilizing the existing motors, retaining the original constant speed capability for emergency service, and using one drive to control several motors sequentially, as well as Improving efficiency. Other benefits often result, such as ease of automation or elimination of on-off duty cycle restrictions. Such a retrofit of a glass tempering Installation is described, with primary emphasis on estimating energy cost savings for justification.