Required Differential Pressure for Rotary Syphons in Paper Dryers

Abstract

Testing of rotary syphons in a 5 ft diameter by 21 ft face length paper dryer has been conducted in order to better understand the effects of blow-thru steam, condensing rate, dryer speed, and dryer pressure on differential pressure. A frictional pressure loss correlation for two-phase flow can be used to calculate the differential pressure. Understanding how these variables affect differential pressure provides a means for determining proper syphon sizing and design. All testing and analysis was done at the Johnson Corporation in Three Rivers, MI. My work at Johnson involved writing a computer program in BASIC which predicts the pressure loss in a rotary syphon. This report explains the equations used in the computer program.