The steam superheaters are arranged direct in line after the waste heat boilers which are connected to the secondary reformer or reformer – depending on the process.

The steam superheater can be provided as two stage or one stage, horizontally or vertically arranged. The final design arrangement is determined by  the process requirements.

We have delivered steam superheaters for superheating saturated steam at a pressure stage of 12,500 kPa from 328 °C to 531 °C by cooling down process gas from 723 °C to 355 °C. Selection of suitable materials due to high temperatures and resistance against metal dusting corrosion will be done by us  based on indepth experience in supplying steam superheaters.

The process steam superheater is usually vertically arranged with U-tubes and a combined steam inlet/outlet chamber. The reformed gas flows on the shell side in a guiding jacket in counterflow to the steam on tube side. The gas outlet temperature requires no refractory lining of the shell. Refractory lining is only provided in the lower bypass area for safety reasons.

The tube sheet is provided with an insulation and an additional heat shield on gas side and is cooled by the steam flow. The guiding jacket is provided with an internal insulation, therefore heat transfer is excluded between cooled down and hot gas. The U-tubes are arranged in such way that the cold shanks for the cold inflowing steam are in the outer section of the tube sheet. The hot shanks are arranged in the center of the tube sheet and are connected to the internal chamber for the hot outflowing steam. This tube arrangement ensures a radial temperature distribution across the thick tube sheet which results in low thermal primary and secondary stresses. The superheater is provided with a pneumatic bypass actuator for controlling the gas outlet temperature as well as the steam superheating temperature.