Reboilers

Question:

            Does superheating steam aid or retard heat transfer?

Answer:

            I had a reboiler on a debutanizer reboiler in Aruba, supplied with 400 psig, 650°F superheated steam. There was a de-superheating station (i.e., a condensate injection point). As I reduced the steam supply temperature (at a constant pressure) with the condensate injection, my reboiler duty did not change. I believe the conventional answer is that superheat retards heat transfer. But, this was not the case in my only field experiment.