Stripper reboiler Heat

[vhd2006]

The heat balance around my sour water stripper indicates the stripper (process fluid) is receiving 50 MMBTU/h from the reboiler, however the saturated steam flow into the reboiler is about 75000 lb/h (equals to about 70 MMBTU/h). Where are the other 20 MMBTU/h (70-50) going to? Is steam going into the condensate return line? The condensate pot level is normally at 40-60 %. Could steam blowing happen even if the condensate pot has liquid seal?
The reboiler has been getting fouled, so the mentioned difference has been increasing over time, and the steam inlet flow has not been affected.

Thank you.

 

[don1980]

There's either an error in your heat balance or an error in the steam flowmeter.

 

[georgeverghese]

LP steam leak into sour water stream at reboiler through corroded tubes?