Watlow Skid-Mounted Thermal System Answers Nitrogen heating Needs

Problemskidded system

A fabricator/engineering firm needed to heat nitrogen to ambient temperature in a cryogenic atmosphere of -320°F. Because of the corrosive environment, the heater and control panel would need to be protected. It also had to meet a pressure drop requirement of less than 0.1psi. Finally, the customer required the entire job to be completed within six weeks.


In designing a solution for the customer, the first consideration was the effect of cryogenics and pressure drop on a system.

Watlow engineering recommended a 140kW, 480V, three-phase circulation heater. The control panel, which had to meet UL® listing requirements, included a Watlow SERIES 965 temperature controller with NEMA 4X rating for corrosion resistance, as well as mercury relays and Watlow's SERIES 140 high-limit controller.

A stainless steel coating protects both the panel and heater from corrosion. To prevent condensate from building up in the enclosure, stand-off housing was used to keep the terminal housing away from the heater flange.

The system was skid-mounted and pre-wired to make installation easier for the customer. When the system arrived, the customer simply had to provide power to the control panel and pipe up to the inlet and outlet connections.

The successful completion of the job in six weeks, plus the ability to design and manufacture a complete thermal system, resulted in a satisfied customer.


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