2014 Spring Meeting & 10th Global Congress on Process Safety
(119f) Kettle Reboiler Hydraulics
Kettle Reboiler Hydraulics
T.J. Cai, M.R. Resetarits* and L. Pless
Fractionation Research, Inc.
424 S. Squires St.
Stillwater, OK 74074
In the chemical processing industry, kettle reboilers are often considered troublesome. The problems are often related to excessive pressure drops caused by liquid entrainment from the kettle reboilers. Information and data regarding kettle hydraulics and entrainment is generally lacking. This paper presents pressure drop and entrainment data obtained from commercial size columns, with different hydrocarbon systems. The entrainment data were collected using gamma ray scanning of the kettle’s vapor product line. An approach for calculating pressure drops across reboilers, and columns, is presented. Regarding the commercial size column, pressure drops are computed for various reboiler heat duties. Head losses of the liquid phase, from the bottom of the column to the reboiler, are estimated via correlations. All hydraulic calculations are compared with experimental data. A good agreement between the measured data and the calculated values was found except at high entrainment levels. A case study, from an industrial size kettle reboiler that had operational problems, will be discussed. A simple solution to some kettle problems involves an extension of the vapor return nozzle in the bottom of the column.
Key Words: Distillation, reboiler, pressure drop, hydraulics, entrainment
*Corresponding author. E-mail: cai@fri.org , Phone: 1-405-385-0354, Fax: 1-405-385-0357