Non-invasive system and procedures for the characterization of liquid–liquid dispersions

Abstract

A novel dispersed phase imaging system for batch/continuous agitated vessels is described in detail, together with the relevant drop-size distribution and data treatment procedures. This system enabled the non-invasive study of toluene-in-water agitated liquid-liquid dispersions. Most of other similar studies are invasive of the system's structure and behavior, which raises questions about the quality of the generated data. Drop-size distributions have been collected and used for testing the representativeness and stability of the samples obtained, and positively assess the physical meaningfulness of the results through the effects of the main operating variables-mean residence time, agitation intensity and dispersed phase hold-up. Inter-drop coalescence clearly shows its effects even in very lean agitated dispersions, and thus cannot be neglected; its modeling, however, is still very much an open question as will be shown in another paper.

Gas/liquid dispersions with a SMX static mixer in the laminar regime

“…This is a proven technique that is also the basis of an online rheological apparatus (Arzate et al, 2002). Many methods allow for the measurement of drops or bubble size (See the review and technique presented in Ribeiro et al, 2004). However, only a few can be used in continuous systems, directly in the pipe, without modifying the prevailing conditions of the flow.…”

An automatic image analysis methodology for the measurement of droplet size distributions in liquid–liquid dispersion: round object detection

“…Zhou, Srinivasan, & Lakshminarayanan, 2009). Ribeiro et al (Ribeiro, Guimares, Madureira, & Pinto, 2004) also utilized videos for the image acquisition process. The video was analyzed frame by frame to characterize the droplets in the studied emulsion.…”

Drop Distribution Determination in a Liquid-Liquid Dispersion by Image Processing

“…This is of importance in simulation, interpretation, and performance predictions of multiphase reactors. As reported in Ribeiro et al [1], authors like Olney [2], Cruz-Pinto and Korchinsky [3] and Rod and Misek [4] have demonstrated that serious design and performance prediction errors occur if drop size distribution is neglected. According to Pacek et al [5], any technique based on representative physical sampling will drastically change the overall composition of the dispersion.…”

“…In Ribeiro et al [1] and Ribeiro [6] a video technique with nonintrusive probes was tested. Pictures of a small region inside a transparent vessel near its wall were obtained, by lighting and observing it from the outside.…”