Our steam superheaters can be used for steam pressures up to 130bar (13,000 kPa) and steam temperatures up to 530°C.
They 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.
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.
In order to prevent heat transfer from the hot to the already cooled gas, the separating and guiding jackets used for flow guidance are thermally insulated.
A refractory lining of the entire shell is not necessary due to the low gas outlet temperature. Only in the area of the bypass is a refactory lining installed for safety reasons.
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.
Im äußeren Bereich wird der Rohrboden durch den rohrseitig strömenden Sattdampf gekühlt. Mantelseitig wird der mittlere Bereich des Rohrbodens durch Isolierung und ein Hitzeschild vor dem heißen Prozessgas geschützt.
Zur Regelung der Gas- und Dampfaustrittstemperatur ist der Dampfüberhitzer mit einem internen gasseitigen Bypass ausgestattet.