![]() ![]() This technique uses a tracer element or marker, such as dye, inorganic salts, or activated radioactive elements, etc., inserted into the feed stream of cells or equipment, generally applied as a pulse, which is then used to analyse the concentration of the tracer in the output, as indicated in Figure 1 ( Levenspiel, 1999 LEVENSPIEL, O. The RTD analysis represents a useful and valuable tool to estimate the mixing quality within equipment, including flotation cells. The degree of mixing in continuous systems. Continuous flow systems: distribution of residence times. The residence time distribution (RTD) theory was created by studying flow in real, continuous systems with the purpose of quantifying any deviations from ideal behaviour ( Danckwerts, 1953 DANCKWERTS, P. However, flow through equipment does not always follow ideal patterns, which may generally interfere with system performances, which thus generates responses below what is expected. Part II: Flow patterns, contacting, and non-ideal flow. New Jersey: Prentice-Hall International, 1992. Elements of chemical reaction engineering. In the design of continuous equipment, the flow is often considered to be ideal, i.e., perfectly agitated or of the piston-flow type ( Fogler, 1992 FOGLER, H. Such processes are known as open systems. In many industrial processes, such as flotation, the equipment is continuously operated with at least one input and one output, through which matter and/or energy is transferred. It was proven that the axial dispersion model parameters (Pe or N d) can be obtained with good precision (R 2 > 0.99) within the evaluated ranges from correlations that use the number of tanks in series (N) values estimated by the tanks-in-series model.įlotation column fluid dynamics residence time distribution The evidence indicates that the axial dispersion and tanks-in-series models agreed well with the experimental data, with a slight advantage of the first model, in terms of obtaining the fluid dynamic parameters. Additionally, a comparative study is performed between different methodologies used to determine RTD hydrodynamic parameters such as fitting of tanks-in-series and axial dispersion models to the experimental data. The objective of the present study is to evaluate the fluid dynamics of a flotation column (2" in diameter and 6 m in height) based on gas hold-up measurements and, in particular, by applying the liquid-phase RTD (residence time distribution) technique.
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