Energy audit of three energy-conserving devices in a steel-industry demonstration program. Task I. Hague forge furnaces. Final report

A program to demonstrate to industry the benefits of installing particular types of energy-conserving devices and equipment was carried out. One of these types of equipment and the results obtained under production conditions in commercial plants are described. The equipment under consideration includes improved forge furnaces and associated heat-recovery components. They are used to heat steel to about 2300 F prior to hot forging. The energy-conserving devices include improved insulation, automatic air-fuel ratio control, and a ceramic recuperator that recovers heat from hot combustion gases and delivers preheated air to high-temperature recirculating burners. Twelve Hague furnaces and retrofit packages were purchased and installed by eleven host forge shops that agree to furnish performance data for the purpose of demonstrating the energy and economic savings that can be achieved in comparison with existing equipment. Fuel savings were reported by comparing the specific energy consumption (Btu's per pound of steel heated) for each Hague furnace with that of a comparison furnace. Economic comparisons were made using payback period based on annual after-tax cash flow. Payback periods for the Hague equipment varied from less than two years to five years or more. In several cases, payback times were high only because the unitsmore » were operated at a small fraction of their available capacity.« less