Liquid attachment and momentum transfer by collisions between free-fall solids and liquid spray droplets

Understanding solid wetting by collisions between flowing solids and spray droplets is essential to optimizing the design and operation of related industrial processes. This paper presents an innovative experimental method to identify the statistical distributions of liquid attachment and collision probability of the impingement of a liquid spray onto free-fall particles. To separate liquid attachment from other contributions to the mass measurements of particles and liquids, individual impingement experiment with hydrophobic or hydrophilic particles of the same otherwise properties is respectively performed under the same conditions. In addition, a series of collection bins are distributed along the spray path to determine the statistical probability of collision properties including coating thickness. Based on these measurements, the collision-induced momentum transfer and velocity redistribution of solids and droplets can be estimated with the aid of a Lagrangian trajectory model. Consequently a general two-parameter of collision probability density function is proposed.

Graphical abstractAn experimental is designed to investigate the statistic distribution of mass and momentum transfer during the collision between free-releasing particles and horizontal water spray jet. Liquid attachment and collision probability density function against with after collision velocity (by tracking the particle trajectory) are obtained. A general two parameter relation is proposed to fit the pdf.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Statistical distributions of liquid attachment are experimentally obtained. ► A model is built up to track the trajectory and after velocity of particles. ► Collision probability density functions against with velocity are obtained. ► A general two parameter relation is proposed to fit the pdf. ► Future directions of the statistical study are proposed.