Experimental Evaluation and Modeling of Condensate Effects in Dryer Cylinders

The presence of a condensate in dryer cylinders during the startup produces an important increase of the required torque and power that adversely affects the drive and mechanical components of the drive train. This paper presents a complete evaluation of the condensate effects in an experimental setup with a 380-mm-diameter cylinder, during operation without and with spoiler bars, and covering from 1% up to 30% of condensate load, and up to 500 r/min. Sets of pictures showing the condensate profile are reported and used to calculate the required power to maintain the condensate distribution. In addition, using values reported for a 1500-mm-diameter production dryer cylinder, a complete set of adimensional correlations are developed that allows the calculation of the power in a speed range from 50 to 1200 m/min, and from 0.2% to 3.4% of condensate content. Results are of interest for those related to the drive rating, as well as for the estimation of condensate content from power readings.