A simulation model for settling tanks with varying cross-sectional area

作者：Burger Raimund; Careaga Julio^*; Diehl Stefan

来源：Chemical Engineering Communications, 2017, 204(11): 1270-1281.

DOI：10.1080/00986445.2017.1360871

• Clarifier-thickener
• continuous sedimentation
• nonlinear conservation PDE
• numerical method
• secondary clarifier

A quasi-one-dimensional model of the process of continuous sedimentation in clarifier-thickeners (settlers) with variable cross-sectional area is presented. The partial differential equation (PDE) model extends the settler model advanced by Burger et al. (2013), which assumes a constant cross section. A reliable numerical method that handles the special features of the nonlinear PDE is presented along with an advantageous time-step condition for continuous and batch sedimentation under the condition of a variable cross-sectional area. Simulations of continuous sedimentation show the effect of change of cross-sectional area in the concentration inside the vessel and in the underflow. Simulations of batch settling in cones illustrate the versatility of the numerical scheme to include a vertex, where the area shrinks to zero.

• 出版日期2017