The ever-increasing cost of natural gas has many heat treaters considering upgrading their existing furnace equipment to include energy-saving features.
The ever-rising natural-gas prices require innovative ways to save energy costs for heat treaters. This was the situation for GalvTech, a major manufacturer of galvanized steel strip. GalvTech is part of The Techs group located in the Pittsburgh, Pa. area. Two other group facilities are NexTech and MetalTech. GalvTech is a state-of-the-art hot-dip galvanizing facility that has been in business since 1996. The company produces galvanized strip in thicknesses ranging from 0.015 to 0.045 in. (~0.4 to 1.14 mm) and up to 61 in. (1,550 mm) wide. GalvTech purchased its furnace equipment from Electric Furnace Co. in 1996 and upgraded it to increase production in 1999, and was looking for ways to beat the ever-increasing price of natural gas.
Electric Furnace Co. entered into an informal working relationship with GalvTech in July 2003 to mutually benefit both companies by improving the control capability of GalvTech's equipment and allowing Electric Furnace Co. to investigate future innovations in process-control technology, innovations which could potentially be incorporated into Galv-Tech's equipment in the future. In December of 2004, GalvTech added the energy saving recuperation addition to its direct gas fired preheat furnace. While the company knew about recuperating technology for many years, the sustained increase in natural-gas prices recently justified installation of recuperation on its line. The company reports that fuel savings at full production conditions after the modification exceed 20%, which translates into substantial energy and cost savings. The following example illustrates how incorporating recuperation in a preheat furnace with an annual production up-time of 7,560 hr (12-hr shift; 2 shifts/day; 315 days/year) translates into substantial energy and cost savings: