Mid-South in Murfreesboro, Tennessee operates a high-energy plant providing precision heat treatments for high-speed tools – and also metal annealing and straightening services. This was a great business to be in before the energy crisis struck. That was about the same time the 2009 recession arrived. In no time at all the market was down 30%.
Investors had a pile of capital sunk into Mid-South’s three facilities spread across 21,000 square feet (2,000 square meters) of enclosed space. Within them, a number of twenty-five horsepower compressors plus a variety of electric, vacuum and atmospheric furnaces pumped out heat 27/7, 52 weeks a year. After the company called in the U.S. Department of Energy for assistance, several possibilities presented.
Insulate the Barium Chloride Salt Baths
The barium chloride salt baths used in the heat treatment process and operating at 1600°F (870°C) were a natural choice, since they could not be cooled below 1200°F (650°C) when out of use without hardening the barium chloride and clogging up the system. The amount of energy taken to prevent this came down considerably after they covered and insulated them. The recurring annual electricity saving was $53,000.
Manage Electrical Demand & Power
The utility delivers 480 volts of power to the three plants that between them consume between 825- and 875-kilowatt hours depending on the season. Prior to the energy crisis Mid-South Metallurgical regarded this level of consumption as a given. Following on the Department of Energy survey the company replaced the laminar flow burner tips with cyclonic burner ones, and implemented a number of other modifications to enhance thermal efficiency further. The overall natural gas reduction was 20%.
Implement Large Scale Site Lighting Upgrade
The 24/7 nature of the business makes lighting costs a significant factor. Prior to the energy upgrade this came from 44 older-type 400-watt metal halide fixtures. By replacing these with 88 x 8-foot (2.5 meter) fluorescent fittings Mid-South lowered maintenance and operating costs by 52%
The Mid-South Metallurgical Trophy Cabinet
These three improvements cut energy use by 22%, reduced peak electrical demand by 21% and brought total energy costs down 18%. Mid-South continues to monitor energy consumption at each strategic point, as it continues to seek out even greater energy efficiency in conjunction with its people.