Case Study:
Dana Corporation

Dana Corporation, a Fortune 100 supplier to the automotive industry, wanted to optimize the operation of heat treating furnaces at its suburban Minneapolis heavy-duty axle plant.

The U. S. Department of Energy and the State of Minnesota Department of Public Service were interested in encouraging industry in the state to innovate to use energy efficiently and to reduce pollution emissions.

With grant PUBLICATIONS from DOE’s Office of Industrial Technology, Energy Efficiency and Renewable Energy, Atmosphere Recovery, Inc., and Dana prototyped and tested new technology for measurement, control and recycling of heat treating furnace gases. Process gas supplier BOC Gases, Inc. and Dow Chemical’s Generon Division, a supplier of nitrogen membrane filters, also contributed to the effort. The prototype system included the predecessor of today’s Laser Gas Analyzer & Controller.

ARI developed a system that used available nitrogen gas separation membrane technology to recover and recycle the nitrogen and carbon monoxide furnace atmosphere gases and maintain them in desired concentrations in a carburizing furnace that hardened ring gears. The test furnace was a large (700 cubic foot per hour) batch unit.

90%+ Savings of Process Gases; 25% Energy Savings

ARI’s system achieved 96% gas recovery, exceeding the 90% project goal. Typical practice had been to flare the process gases to the environment after their use.

The heat treated parts were carburized (case hardened) to the specified depth—or better—during the same process cycles that had been used with an unmodified furnace (six to twelve hours, followed by rapid quenching).

The test indicated that with improved furnace sealing the new gas control system had the potential to reduce carbon monoxide use and emissions to less than 10% of levels conventional at the time. Potential savings of at least 25% of process energy used also were indicated.

The prototype was considered an unqualified success, with prospects to achieve additional manufacturing economies from automation, predictive failure maintenance, lower part rejects and increased throughput.

In addition to potential energy and process gas savings, the atmosphere recovery system tests indicated that emissions of CO, nitrogen oxides and sulphur oxides could be reduced below federal and state permit thresholds. In practice, this eliminated the need for some $100,000 of pollution monitoring and control equipment and an estimated $30,000 per year for pollution monitoring, reporting and emission permit fees.

Details of this demonstration project are covered in the fact sheet and both titled Atmosphere Recovery and Regeneration in Heat Treating Operations, available in the technical articles section of this site.