Agglomeration of carbonaceous particles in a pendant water slurry droplet

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2024-11, Vol.703, p.135318, Article 135318
• Main Authors: Islamova, Anastasia, Strizhak, Pavel
• Format: Article
• Language: English
• Subjects: Agglomeration rate; Colloidal particles; Pendant droplet; Sedimentation; Stratification rate
• ISSN: 0927-7757
• DOI: 10.1016/j.colsurfa.2024.135318

Liquid spraying is used in a number of engineering applications, such as spray cooling, drying, granulation, etc., which mostly deal with colloidal solutions or slurries. Depending on the application, solid particle agglomeration can be considered a positive or negative phenomenon. Therefore, to make engineering processes reliable and stable, it is necessary take account of secondary processes affecting the size distribution of the material involved. The agglomeration of solid particles in a pendant droplet was studied experimentally. Distilled water was used as the base liquid and 60–120-μm coal particles as solid inclusions. The coal concentration in a droplet was varied in the range of 0.5–10 %. The main parameters of particle agglomeration in a droplet were recorded using the shadow method. Particle sedimentation velocities and heights of the agglomerated particle layers in a droplet were recorded as part of the experiments. These characteristics were affected by the initial liquid volume, relative particle concentration and size. Equations were obtained for the relationships determined in the experiments. These equations can help extrapolate the corresponding functions to wider variation ranges of input parameters. Recommendations have been formulated on managing the processes of slurry droplet stratification over time. [Display omitted] •Sedimentation velocities were established for solid particles in a pendant droplet.•Thickness of agglomerated particle layers were determined in a droplet.•Sedimentation behavior depends on particle size and concentration in a droplet.•Initial droplet volume has a significant impact on particle sedimentation velocities.•Equations were obtained for particle agglomeration characteristics as functions of time.