How Watt Density Specifications May Be Holding Back Optimal Electric Heat Exchanger Design

Typical customer specifications for a direct electric heat exchanger (DEHE) in forced convection gas applications aim for efficiency and safety given the technology principles that have been in place for the last two decades. For example, this has led to specifications calling for lower heat fluxes (watt densities) to maintain safe sheath temperatures reliably. More recently, newer technologies allow for higher watt densities while maintaining both safety and reliability. While the older specifications are conservative and safe, the design may be sub-optimal. Letting go of the assumption that watt density is roughly equivalent to a safe sheath temperature helps open up the possibilities of new design solutions, many of which can reduce overall footprint and make processes more efficient and less costly.