The furnace will feature an efficient, graphite-insulated hot zone to operate up to 2,650 degrees Fahrenheit. The ultimate capability of the vacuum will be 10-5 torr. A high-pressure radial fan will re-circulate nitrogen gas at two atmospheres. An Allen-Bradley variable speed drive will control the 10 hp quench motor.
The SolarVac 3000, Solar Manufacturing's interactive control system, will monitor and control the LPVC process. The controls feature a Honeywell UDC2500, and Allen-Bradley Micrologix 1500 PLC for the temperature and process control, several Porter Instrument absolute gas flow controllers, an MKS absolute vacuum gauge and a Eurotherm Graphic Display video recorder for data acquisition.
"The customer and the Solar development team have been collaborating for nearly three years to develop the process for LPVC," says Pete Reh, vice president of sales for Solar Manufacturing. "The furnace will help prove out LPVC to optimize the vacuum carburizing process with positive pressure gas quenching as opposed to atmospheric carburizing with oil quenching."
Solar was recently awarded a patent for a high-velocity integral vacuum furnace that includes the LPVC process, which uses acetylene and hydrogen gas ratios at pressures under 15 torr and preheating in a hydrogen atmosphere for surface activation.