Making synthetic fibers requires a lot of heat and precise control. So, when a North Carolina manufacturer of specialty synthetic fibers used in both industrial and home applications required a custom autoclave for a drying application, the company went to a specialist: Pittsburgh-based Chromalox.

Rather than use equipment relying on a fossil fuel, the customer chose an autoclave that utilizes nitrogen as the heat transfer medium via forced convection. Temperatures range between 400 and 500°F (204 and 260°C) in the system’s base-heat load. Each of the nine individual zones within the system has its own temperature- and power-control loop for precision control.

Baseline heating of the nitrogen loop was provided by a Chromalox 35 KW GCHIS circulation heater; the company’s fintube tubular heating elements with Incoloy sheaths heated the autoclave’s interior. Nine 5 KW circulation heaters heated individual loops within the system. Each of the loops are controlled by the company’s SCR power controllers, part of the autoclave’s main control panel. The power control panels allow precision control of each loop, utilizing high temperatures and low gas flow.

Satisfied with the fuel-cost savings and precision quality control for reliable product quality, the customer purchased a similar system retrofitted to an existing autoclave. For more information on Chromalox, go to