An assessment of the potential of shadow sizing analysis and Particle Image Velocimetry (PIV) to characterise hot trub morphology

Abstract

Methods for mixture particles imaging are increasingly popular in many fields of engineering research. Particularly interesting is application of imaging techniques in the case of mixtures which by their nature take the form of agglomerates inside the flow. There are cases in which introduction of sensors into the flow system is not possible. What is also very often impossible is to perform mixture initial homogenization, required by many measurement apparatuses, due to the fact that such a measurement does not provide reliable information about dispersed phase's morphology. An example of such a case is analysis of the so-called hot trub which is formed during beer wort boiling. Determination of the hot trub amount and knowledge of distribution of its particles' size are the key elements impacting the criteria of optimization of this type of separator's structure. While the sediment particles are traveling towards the bottom the sediment's volumetric share is considerable, which further impedes the analysis of the investigated system. Therefore, in the case of hot trub (which is a mixture with high concentration of dispersed phase), using a non-invasive method based on analysis of digital images is a justified choice. This paper presents an application of the Shadow Sizing method for identification of morphological parameters (diameter) of hot trub particles. Abilities and limitations in detection of hot trub particles traveling within an interrogation cell have been determined. An application of the shadow analysis as a method for determination of dispersed phase's velocity. A way of drawing conclusions from obtained images, later used for PIV analysis with LMS and Adaptive PIV algorithms, has been presented.