Liquid Film Thickness Measurements in a Horizontally
Rotating Cylinder
Alex Barr¹, Suppiah Singaram Saravanan², Roshan Jachuck³
Department of Chemical and Biomolecular Engineering
Process Intensification and Clean Technology (PICT) group has been developing thin film reactors such
as micro-reactors and rotating tube reactors to efficiently process chemicals. The objective of this work is to study
experimentally the thickness of a liquid film inside a horizontally rotating cylinder and to check the validity of the
model equation given by Cowen et al. (1982). The knowledge of the exact film thickness produced in rotating
equipment is critical in predicting the performance of the equipment.
Cowen et al. states that with the knowledge of flow rate (Q), length of the cylinder (L), viscosity (ʋ),
radius (R), and rotational speed (ω), the thickness of a liquid film can be calculated by using
. In
this study, the length, viscosity, and radius were constant, and film thickness was measured by altering the flow
rate of the liquid and rotational speed of the cylinder. For each flow rate and rotational speed, the film thickness
was measured using an optical technique. A model equation to predict the experimental film thickness values is
developed and also the model equation developed by Cowen et al. is used to predict the film thickness. The model
equation developed in this work is given by
where ψ and ζ are the fitting parameters. The constants
that best fit the model equation to the experimental data are determined.
Figure 1 represents the general trend in the relationship between Cowen et al. curve and the curve that best
matches the experimental data. From Figure 1, it can be seen that Cowen et al. under-predicts the film thickness
values that are experimentally measured. Cowen et al. generated their model equation based on their experimental
studies conducted at higher rotational speeds. Since the rotational speeds studied in this work is in the lower range
(300 to 900 rpm), Cowen et al. under-predicts the film thickness values. Hence, the model equation developed in
this work can be used to predict the film thickness values in the lower range of rotational speeds.
1. 2011, Engineering Studies, Clarkson University, Honors Program
2. Student, Department of Chemical and Biomolecular Engineering, Clarkson University
3. Research Associate Professor, Department of Chemical and Biomolecular Engineering, Clarkson University
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Figure 1
Cowen, G., Philip Norton-Berry & Steel, M.L. (1982) Chemical process on the surface of a rotating body. U.S Patent
#4,311,570.
Saravanan, Suppiah Singaram, (2007) Single-phase rimming flow of a liquid in a rotating horizontal cylinder. PhD Proposal.
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