Abstract
Electrostatic rotary bell sprayers (ERBSs) are widely used in the automotive industry. In ERBS, atomization is facilitated using centrifugal forces which disintegrate the paint film inside the cup into droplets at the cup edge. The droplets are then transported by the flow of a shaping air (SA) and electrostatic forces to a target surface; the characteristics of these droplets dramatically influence the quality of a painted surface and the painting transfer efficiency. In the current paper, a novel Schlieren-based visualization of the shaping air in the absence of paint droplets was performed during a qualitative investigation to delineate shaping air flow behavior and its interaction with droplets and droplet transport. An infrared thermographic flow visualization (IRFV) method and droplet size measurement were used to complement the Schlieren data for providing insight into shaping air-droplet interactions. The results demonstrated the impact of different operating conditions on the SA flow pattern, and the influence SA has on the secondary atomization and transport of droplets. Hence, these experimental methods combine with a useful tool for optimizing SA configurations that improve spray quality, droplet transport, and the efficiency of ERBS operations.
Document Type
Article
Publication Date
8-11-2018
Digital Object Identifier (DOI)
https://doi.org/10.3390/coatings8080279
Funding Information
This research was funded internally by the University of Kentucky, Institute of Research for Technology Development (IR4TD).
Related Content
The following are available online at https://www.mdpi.com/2079-6412/8/8/279/s1, Video S1: Shaping air only at 50 LPM SA flow rate and 0 kRPM rotational speed; Video S2: Shaping air only at 50 LPM SA flow rate and 20 kRPM rotational speed; Video S3: Shaping air only at 50 LPM SA flow rate and 50 kRPM rotational speed; Video S4: Shaping air only at 150 LPM SA flow rate and 0 kRPM rotational speed; Video S5: Shaping air only at 150 LPM SA flow rate and 20 kRPM rotational speed; Video S6: Shaping air only at 150 LPM SA flow rate and 50 kRPM rotational speed; Video S7: Shaping air only at 250 LPM SA flow rate and 0 kRPM rotational speed; Video S8: Shaping air only at 250 LPM SA flow rate and 20 kRPM rotational speed; Video S9: Shaping air only at 250 LPM SA flow rate and 50 kRPM rotational speed.
Repository Citation
Ahmad, Adnan Darwish; Abubaker, Ahmad M.; Salaimeh, Ahmad A.; and Akafuah, Nelson K., "Schlieren Visualization of Shaping Air During Operation of an Electrostatic Rotary Bell Sprayer: Impact of Shaping Air on Droplet Atomization and Transport" (2018). Institute of Research for Technology Development Faculty Publications. 1.
https://uknowledge.uky.edu/ir4td_facpub/1
Supplementary Material
Notes/Citation Information
Published in Coatings, v. 8, issue 8, 279, p. 1-13.
© 2018 by the authors. Licensee MDPI, Basel, Switzerland.
This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).