Liquid-liquid separation using steady-state bed coalescer

Radmila Secerov-Sokolovic,Dragan Govedarica,Dunja Sokolovic

doi:10.2298/hemind150309041s

Abstract

This paper presents a literature review on the current understanding of liquid-liquid separation that is immensely widespread in practice, highlighting the steady-state bed coalescer being a good solution in various engineering application. Generally, the fibre bed coalescence has proven to be very effective separation method in the industry. Due to the complexity of bed coalescence phenomenon coalescer design and sizing procedure relies on experimental test. This review provides a research overview of the key phenomena essential for the efficient bed coalescence, such as mechanisms of droplet coalescence and emulsion flow through the fibre bed. In addition to this provides an overview of the current knowledge about coalescer?s design properties and variables such as: fluid velocity, fluid flow orientation/flow mode, fibre bed geometry, and bed length.

Highlights

Coalescence is defined as droplets drowning either in its formed continuous phase or as merging two droplets into a larger one
The beginning of the investigation of coalescence phenomenon is based on the analogy with the DLVO theory
In 1941 Derjaguin and Landau presented a theory of stability of colloidal particles as a function of the attractive and repulsive forces [6]

Summary

Introduction

Coalescence is defined as droplets drowning either in its formed continuous phase or as merging two droplets into a larger one. In the case of deep bed filtration the amount of capillary-conducted phase changes in the pore volume, increasing quantity of the disperse phase This regime is unsteady-state due to the change of pressure drop with time [47]. Three coalescence mechanisms can occur in the porous bed: coalescence of the droplets on the fibre surface, coalescence of the adjacent droplets in the pore space and coalescence of the droplets on the surface of the capillary-conducted disperse phase, saturated liquid [3,42,43,44,45,46]. With the coalescence of droplets on the surface of the solid material the formation of capillary-conducted phase in pores is obtained. Mutual drop coalescence in the pores may be enhanced by the bed properties that influence the distance between drops and favouring this type of coalescence [3,5,9,48,49,50,51,52,53,54]

DESIGN VARIABLES OF BED COALESCER

Findings

DISCUSSION AND OUTLOOK