The Two-Phase Conical Swirl Atomizers: Spray Characteristics

Andżelika Krupińska,Marek Ochowiak,Małgorzata Markowska,Marcin Janczarek,Tomasz Szulc,Sylwia Włodarczak,Magdalena Matuszak

doi:10.3390/en13133416

Abstract

This paper presents the results of experimental studies on two-phase conical swirl atomizers. The impact of various atomizer geometries and different operational parameters of the atomization process on the spray characteristics was investigated. The influence of the mixing chamber height HS to diameter DS ratio and the volumetric flow rates of liquid and gas on the discharge coefficient values, spray angle, droplet size expressed by Sauter mean diameter D32, volumetric and radial distributions of droplet diameters in the spray stream were determined. The analysis of results showed that the discharge coefficient values depend on the Reynolds number for liquid and gas and the atomizer geometry. The spray angle increases as the flow rate of liquid and gas increases depending on the applied atomizer construction. The Sauter mean diameter value is correlated with the geometric dimensions of the atomizer swirl chamber. The rapid increase in D32 occurs after exceeding the value HS/DS ≈ 3. The Sauter mean diameter also depends on the operating parameters. A central area of stream is filled with smaller sized droplets as the gas flow rate increases.

Highlights

The atomization of liquids is an important and interesting large-scale process used in many industries [1,2]
The results showed that the appropriate ratio of the atomizer characteristic dimensions allowed the production a stream with possibly the lowest values of mean droplet diameters and spray angle [42]
The value of the discharge coefficient increases with the increase in ReL value, whereas, with the increase in ReG value, it decreases

Summary

Introduction

The atomization of liquids is an important and interesting large-scale process used in many industries [1,2]. Among others, fields of the economy such as agrotechnics, energy engineering, machine industry, transport and communication, chemical engineering and environmental protection. This process involves a stream of liquid transformation into small droplets, which increases the surface to volume ratio. Atomization is mainly applied to increase the liquid surface and intensify the heat and mass exchange processes between the liquid and gas phases [3]. This process requires the use of external energy to overcome surface tension forces, which can be performed in various ways: using gas energy or ultrasound, mechanically or electrically [4,5,6,7]. It is important to focus the treatment on a specific goal and Energies 2020, 13, 3416; doi:10.3390/en13133416 www.mdpi.com/journal/energies

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Conclusion