Watlow Fuel Oil Preheater Designed for Ease of Operation

Problemfuel oil preheater

To improve burner efficiency, an electric utility company needed to preheat #6 fuel oil. This required a powerful heater large enough to handle 300 GPM of fuel. In addition, a number of ASME codes and NEMA 4X specifications had to be met.


After surveying the customer's lengthy list of specifications, Watlow recommended a 10 foot long, 18 inch diameter circulation heater with 640kW of power. To ensure corrosion resistance, Watlow designed an oversized NEMA 4X enclosure and met special sandblasting and painting requirements.

A Watlow SCR power control and panel were designed with special local/remote interlocks so the customer could operate the system either from the control center or at the plant site. This panel system was completed less than six weeks after receiving the customer's approval.

In addition to meeting the customer's specifications, the Watlow engineering staff also suggested several design enhancements, such as pre-wired heater branch circuits that provided ease of customer wiring as well as extra electrical clearance. Watlow also designed special lifting lugs to facilitate easy removal of the element bundle and a mounting skid, customized for the heating system, to make installation easier.

The powerful heating system from Watlow has allowed the utility company to improve burner efficiency by 10-12 percent.