What happens to the dryer section drive load if one of the dryers is flooded?

Process Optimization

It depends. If the dryer is running at a high speed (say, 3500 fpm) and the condensate is rimming, there may be no noticeable change in dryer drive power. 

At a low speed, however, where the condensate is not rimming, the drive load could be over 5x higher than a dryer with proper condensate drainage. This increase in drive load can be enough that just one flooded dryer will trip the drive motor. Consistent, stable, and reliable dryer drainage is important to machine operating efficiency.

Source: Kadant