Heat and Mass Transfer in Agitated, Co-, or Countercurrent Conductive-Convective Heated Drum Dryer

作者：Poos Tibor^*; Oervoes Maria

来源：Drying Technology, 2012, 30(13): 1457-1468.

DOI：10.1080/07373937.2012.689402

• Conductive-convective
• Drum dryer
• Nusselt number
• Reynolds number
• Transfer coefficients

Agitating drum dryers are often used to dry granular solids with high moisture contents. Moisture reduction and thermal treatment can be enhanced by a contact heating jacket or heated agitators. A mathematical model was created to investigate the influence of operating parameters for the description of simultaneous heat and mass transfer in a dryer. The model contains volumetric heat and mass transfer coefficients that are functions of temperature, velocity, etc. To investigate the drying process and to determine the volumetric heat transfer coefficients, a pilot-plant agitating dryer was built. Measurement and evaluation methods were developed to determine the volumetric heat transfer coefficients of granulated products. The volumetric heat transfer coefficients were plotted with dimensionless Nu%26apos;-Re%26apos; numbers. The mathematical model and the transfer coefficients make it possible to calculate the moisture content and temperature of the drying product as well as the humidity and temperature of the drying gas along the dryer length for convective, conductive, cocurrent, and countercurrent case.

• 出版日期2012