Management of Acute Particulate Fouling in a Titanium Dioxide Reactor System

ABSTRACT

The gas-phase manufacture of titanium dioxide is subject to acute fouling in the cooler unit located directly downstream of the reactor which quenches the reaction. A model of the cooler system was constructed, incorporating aspects of compressible flow, multimode heat transfer, fouling, and changes in geometry. This indicated that deposition could be very rapid. The effect of deposit layer buildup required measurement of the thermal conductivity of the porous layer; this was achieved using a novel testing device similar to that reported by Tan et al. (2006), for measuring the thermal conductivity of surface coatings. Active mitigation techniques are employed to reduce the effect of rapid fouling. The effectiveness of adding an erodent, in this case sand, to the flow was appraised by studying the breakup of deposit layers by impinging particles. The experimental conditions (high-temperature chlorine gas, high flow velocities) were simulated in cold experiments by matching the inertia and size of test particles to those of the sand. These studies showed that sand at the feed size would detach deposits, but could result in breakage of the sand particles. Mitigation efficiency is then determined by sand distribution and redistribution.

Funding

Funding for VYL from Huntsman is gratefully acknowledged, as are helpful conversations with Ian Hutchings and Bill Clyne. The thermal conductivity rig was constructed by Gary Chapman and WeiYao Ma.

Disclaimer

All information contained herein is provided “as is” without any warranties, express or implied, and under no circumstances shall the authors or Huntsman be liable for any damages of any nature whatsoever resulting from the use or reliance upon such information. Nothing contained in this paper should be construed as a license under any intellectual property right of any entity, or as a suggestion, recommendation, or authorization to take any action that would infringe any patent. The term “Huntsman” is used herein for convenience only and refers to Huntsman Corporation, its direct and indirect affiliates, and their employees, officers, and directors.

Additional information

Notes on contributors

Vincent Y. Lister

Vincent Lister is an application engineer at CD-adapco working with the computational fluid dynamic software STAR-CCM+. He received his Ph.D. in chemical engineering from the University of Cambridge and worked at the University of Bath as a research associate on single-use biotechnology. He is currently working on industrial fluid dynamic engineering problems.

John F. Davidson

John Davidson F.R.S., F.R.Eng., was on the academic staff of the Department of Chemical Engineering, Cambridge University, from 1952 till he retired in 1993; he was head of the department from 1975 to 1993. His primary research was on fluidization (three books). He has also published on combustion, rotary kilns, granular flow, and water jet cleaning. He was president of the Institution of Chemical Engineers, 1970–1971.

Stephen J. Sutcliffe

Stephen Sutcliffe, F.I.Chem.E., is a technology expert in the chloride process for Huntsman Pigments and Additives, having held various roles in manufacturing and engineering. He studied chemical engineering at Imperial College London, and now manages a number of external collaborations for the company, both in the United Kingdom and overseas.

D. Ian Wilson

Ian Wilson, F.I.Chem.E., is Professor of Soft Solids and Surfaces in the Department of Chemical Engineering and Biotechnology at Cambridge University. He studied chemical engineering at Cambridge and University of British Columbia. He is interested in food processing and the flow of complex fluids. He was awarded an Sc.D. from Cambridge University in 2013 for his work on fouling and cleaning