Electric process heater with higher flux heating elements in zones of perpendicular flow

An electric process heater comprising:

• a vessel containing a heat-transfer fluid;
• a plurality of elongated heating elements extending inside the vessel, the plurality of elongated heating elements comprising a first subset of elongated heating elements having a higher surface flux than a second subset of elongated heating elements;
• and
• a plurality of baffles disposed inside the electric process heater and having holes through which the elongated heating elements extend, wherein the heat-transfer fluid flows in a longitudinal flow zone where the fluid flows along the elongated heating elements and in a crossflow zone where the fluid flows between adjacent baffles across the elongated heating elements, wherein the first subset of elongated heating elements is disposed in the crossflow zone and wherein the second subset of elongated heating elements is disposed in the longitudinal flow zone.

An electric process heater comprising:

• a vessel containing a heat-transfer fluid;
• a plurality of elongated heating elements extending inside the vessel, the plurality of elongated heating elements comprising higher surface flux heating elements and lower surface flux heating elements;
• and
• a plurality of baffles disposed inside the electric process heater and having holes through which the elongated heating elements extend, wherein the heat-transfer fluid flows in a longitudinal flow zone where the fluid flows along the elongated heating elements and in a crossflow zone where the fluid flows between adjacent baffles across the elongated heating elements, wherein the higher surface flux heating elements are disposed in the crossflow zone and wherein the lower surface flux heating elements are disposed in the longitudinal flow zone.