Liquid phase mixing in a slurry bubble column with draft tube

E. Ventura-Medina, F. F. Pironti, A. E. Saez

Research output: Contribution to journalArticle

Abstract

In this work we characterize liquid phase mixing in a 150 L bubble column with a draft tube (internal airlift configuration) for a water-air-sand system at high solid concentrations. Liquid mixing is assessed by measuring the evolution of sodium chloride concentration after a pulse of concentrated NaCl solution is injected. Tracer concentrations were measured by means of electrical conductivity probes. The experimental set up consists of a 0.29 m internal diameter, 3 m length Plexiglas column with a conical bottom (cone apex angle of 60°) and a concentric draft tube with 0.14 m internal diameter and 2 m length. The gas superficial velocity based on the cross section of the column vaired from 0.057 to 0.22 m/s. Sand particles of 280 μm in average size were used, with slurry concentrations ranging from 120 to 500 kg/m3. From the tracer outputs, circulation time (time between peaks of the response curve) and mixing time (time required to achieve a 95% homogeneous solution) were determined after the pulse had been injected. The experimental data were analyzed by means of a tank in series model with recirculation. The circulation and mixing times were found to increase with solids concentration, and to decrease as the riser gas velocity was increased. The circulation limes were larger in continuous operation than in semibatch mode. The results show that the system has equivalent dispersion coefficients that are one order of magnitude lower than those found in a conventional bubble column.
Original languageEnglish
Pages (from-to)219-231
Number of pages13
JournalChemical Engineering Communications
Volume163
Issue number1
DOIs
Publication statusPublished - 1998

Fingerprint

Bubble columns
Liquids
Sand
Gases
Polymethyl Methacrylate
Sodium chloride
Sodium Chloride
Cones
Water
Air

Keywords

  • bubble column
  • airlift reactor
  • draft tube
  • liquid mixing

Cite this

Ventura-Medina, E. ; Pironti, F. F. ; Saez, A. E. / Liquid phase mixing in a slurry bubble column with draft tube. In: Chemical Engineering Communications. 1998 ; Vol. 163, No. 1. pp. 219-231.
@article{08c6cce3a1294dd4a4669fe63e32151d,
title = "Liquid phase mixing in a slurry bubble column with draft tube",
abstract = "In this work we characterize liquid phase mixing in a 150 L bubble column with a draft tube (internal airlift configuration) for a water-air-sand system at high solid concentrations. Liquid mixing is assessed by measuring the evolution of sodium chloride concentration after a pulse of concentrated NaCl solution is injected. Tracer concentrations were measured by means of electrical conductivity probes. The experimental set up consists of a 0.29 m internal diameter, 3 m length Plexiglas column with a conical bottom (cone apex angle of 60°) and a concentric draft tube with 0.14 m internal diameter and 2 m length. The gas superficial velocity based on the cross section of the column vaired from 0.057 to 0.22 m/s. Sand particles of 280 μm in average size were used, with slurry concentrations ranging from 120 to 500 kg/m3. From the tracer outputs, circulation time (time between peaks of the response curve) and mixing time (time required to achieve a 95{\%} homogeneous solution) were determined after the pulse had been injected. The experimental data were analyzed by means of a tank in series model with recirculation. The circulation and mixing times were found to increase with solids concentration, and to decrease as the riser gas velocity was increased. The circulation limes were larger in continuous operation than in semibatch mode. The results show that the system has equivalent dispersion coefficients that are one order of magnitude lower than those found in a conventional bubble column.",
keywords = "bubble column, airlift reactor, draft tube, liquid mixing",
author = "E. Ventura-Medina and Pironti, {F. F.} and Saez, {A. E.}",
year = "1998",
doi = "10.1080/00986449808912352",
language = "English",
volume = "163",
pages = "219--231",
journal = "Chemical Engineering Communications",
issn = "0098-6445",
number = "1",

}

Liquid phase mixing in a slurry bubble column with draft tube. / Ventura-Medina, E.; Pironti, F. F.; Saez, A. E.

In: Chemical Engineering Communications, Vol. 163, No. 1, 1998, p. 219-231.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Liquid phase mixing in a slurry bubble column with draft tube

AU - Ventura-Medina, E.

AU - Pironti, F. F.

AU - Saez, A. E.

PY - 1998

Y1 - 1998

N2 - In this work we characterize liquid phase mixing in a 150 L bubble column with a draft tube (internal airlift configuration) for a water-air-sand system at high solid concentrations. Liquid mixing is assessed by measuring the evolution of sodium chloride concentration after a pulse of concentrated NaCl solution is injected. Tracer concentrations were measured by means of electrical conductivity probes. The experimental set up consists of a 0.29 m internal diameter, 3 m length Plexiglas column with a conical bottom (cone apex angle of 60°) and a concentric draft tube with 0.14 m internal diameter and 2 m length. The gas superficial velocity based on the cross section of the column vaired from 0.057 to 0.22 m/s. Sand particles of 280 μm in average size were used, with slurry concentrations ranging from 120 to 500 kg/m3. From the tracer outputs, circulation time (time between peaks of the response curve) and mixing time (time required to achieve a 95% homogeneous solution) were determined after the pulse had been injected. The experimental data were analyzed by means of a tank in series model with recirculation. The circulation and mixing times were found to increase with solids concentration, and to decrease as the riser gas velocity was increased. The circulation limes were larger in continuous operation than in semibatch mode. The results show that the system has equivalent dispersion coefficients that are one order of magnitude lower than those found in a conventional bubble column.

AB - In this work we characterize liquid phase mixing in a 150 L bubble column with a draft tube (internal airlift configuration) for a water-air-sand system at high solid concentrations. Liquid mixing is assessed by measuring the evolution of sodium chloride concentration after a pulse of concentrated NaCl solution is injected. Tracer concentrations were measured by means of electrical conductivity probes. The experimental set up consists of a 0.29 m internal diameter, 3 m length Plexiglas column with a conical bottom (cone apex angle of 60°) and a concentric draft tube with 0.14 m internal diameter and 2 m length. The gas superficial velocity based on the cross section of the column vaired from 0.057 to 0.22 m/s. Sand particles of 280 μm in average size were used, with slurry concentrations ranging from 120 to 500 kg/m3. From the tracer outputs, circulation time (time between peaks of the response curve) and mixing time (time required to achieve a 95% homogeneous solution) were determined after the pulse had been injected. The experimental data were analyzed by means of a tank in series model with recirculation. The circulation and mixing times were found to increase with solids concentration, and to decrease as the riser gas velocity was increased. The circulation limes were larger in continuous operation than in semibatch mode. The results show that the system has equivalent dispersion coefficients that are one order of magnitude lower than those found in a conventional bubble column.

KW - bubble column

KW - airlift reactor

KW - draft tube

KW - liquid mixing

UR - http://www.tandfonline.com/loi/gcec

U2 - 10.1080/00986449808912352

DO - 10.1080/00986449808912352

M3 - Article

VL - 163

SP - 219

EP - 231

JO - Chemical Engineering Communications

JF - Chemical Engineering Communications

SN - 0098-6445

IS - 1

ER -