0
Research Papers: Heat and Mass Transfer

Air-Mist Heat Extraction and Visualization of Droplets–Surface Interactions From 60 to 1200 °C Under Steady-State Conditions

[+] Author and Article Information
M. Enrique Huerta L

Department of Manufacturing Engineering,
Universidad Politécnica de Ramos Arizpe,
De las Américas,
Ramos Arizpe 25900, Coahuila, Mexico
e-mail: 24r10huerta@gmail.com

Tania M. Flores F

Laboratory of Process Metallurgy,
Department of Metallurgical Engineering,
Centro de Investigación y de
Estudios Avanzados,
CINVESTAV—Unidad Saltillo,
Av. Industria Metalúrgica 1062,
Parque Ind. Saltillo-Ramos Arizpe,
Ramos Arizpe 25900, Coahuila, Mexico
e-mail: tania.floresf@cinvestav.edu.mx

Claudia Barraza de la P

Laboratory of Process Metallurgy,
Department of Metallurgical Engineering,
Centro de Investigación y de
Estudios Avanzados,
CINVESTAV—Unidad Saltillo,
Av. Industria Metalúrgica 1062,
Parque Ind. Saltillo-Ramos Arizpe,
Ramos Arizpe 25900, Coahuila, Mexico
e-mail: claudia.barraza@cinvestav.edu.mx

A. Humberto Castillejos E

Laboratory of Process Metallurgy,
Department of Metallurgical Engineering,
Centro de Investigación y de
Estudios Avanzados,
CINVESTAV—Unidad Saltillo,
Av. Industria Metalúrgica 1062,
Parque Ind. Saltillo-Ramos Arizpe,
Ramos Arizpe 25900, Coahuila, Mexico
e-mail: humberto.castillejos@cinvestav.edu.mx

1Corresponding author.

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received July 25, 2017; final manuscript received October 31, 2017; published online March 9, 2018. Assoc. Editor: Amy Fleischer.

J. Heat Transfer 140(6), 062003 (Mar 09, 2018) (16 pages) Paper No: HT-17-1430; doi: 10.1115/1.4038792 History: Received July 25, 2017; Revised October 31, 2017

Heat extraction and drop impact regimes occurring when a local portion of a horizontal flat-fan air mist impinges the active surface of a Pt disk hold at Tw from ∼60 to 1200 °C are investigated. Boiling curves comprise single-phase, nucleate boiling (NB), transition boiling (TB), and film boiling (FB). Mists are generated under wide ranges of water and air flow rates, and the disk is placed at center and off-center positions along the mist footprint major axis. Conditions generate a wide spectrum of water impact flux, w, droplet diameter, dd, droplet velocity, uzs, and impingement angle. Heat flux extracted, −q, along each boiling regime correlates very well with expressions involving Reynolds, Weber, and Jakob numbers evaluated in terms of local average characteristics of free nonimpinging mists—w, volume mean diameter, d30, normal volume weighted mean velocity, uz,v—and Tw; close estimation indicates that hydrodynamic and thermal forces are well accounted. During arrival of sparse parcels visualization of mist–wall interactions, using a high speed camera aided by laser illumination, allows determination of the predominance area diagram of droplet impact regimes in terms of normal impinging Weber number, Wez, and Tw. The regimes include stick, rebound, spread, and splash; the last subclassified as fine-, crown- and jet-atomization. Arrival of parcels in close succession is ubiquitous causing rapid surface flooding and leading to formation of discontinuous well agitated thick liquid films, which interacts longer with the surface than drops in sparse parcels, acting as heat sinks for longer periods of time.

FIGURES IN THIS ARTICLE
<>
Copyright © 2018 by ASME
Your Session has timed out. Please sign back in to continue.

References

Mudawar, I. , and Valentine, W. S. , 1989, “Determination of the Local Quench Curve for Spray-Cooled Metallic Surfaces,” J. Heat Treat., 7(2), pp. 107–121. [CrossRef]
Graham, K. M. , and Ramadhyani, S. , 1996, “Experimental and Theoretical Studies of Mist Jet Impingement Cooling,” ASME J. Heat Transfer, 118(2), pp. 343–349. [CrossRef]
Jia, W. , and Qiu, H.-H. , 2003, “Experimental Investigation of Droplet Dynamics and Heat Transfer in Spray Cooling,” Exp. Therm. Fluid Sci., 27(7), pp. 829–838. [CrossRef]
Estes, K. A. , and Mudawar, I. , 1995, “Correlation of Sauter Mean Diameter and Critical Heat Flux for Spray Cooling of Small Surfaces,” Int. J. Heat Mass Transfer, 38(16), pp. 2985–2996. [CrossRef]
Chen, R.-H. , Chow, L. C. , and Navedo, J. E. , 2002, “Effects of Spray Characteristics on Critical Heat Flux in Subcooled Water Spray Cooling,” Int. J. Heat Mass Transfer, 45(19), pp. 4033–4043. [CrossRef]
Schmidt, J. , and Boye, H. , 2001, “Influence of Velocity and Size of the Droplets on the Heat Transfer in Spray Cooling,” Chem. Eng. Technol., 24(3), pp. 255–260. [CrossRef]
Hernández-Bocanegra, C. A. , Castillejos, E. A. H. , Zhou, X. , and Thomas, B. G. , 2013, “Measurement of Heat Flux in Dense Air-Mist Cooling—Part I: A Novel Steady-State Technique,” Exp. Therm. Fluid Sci., 44, pp. 147–160. [CrossRef]
Huerta, L. M. E. , Mejía, G. M. E. , and Castillejos, E. A. H. , 2016, “Heat Transfer and Observation of Droplet-Surface Interactions During Air-Mist Cooling at CSP Secondary System Temperatures,” Metall. Mat. Trans. B, 47(2), pp. 1409–1426. [CrossRef]
Hernández-Bocanegra, C. A. , Castillejos, E. A. H. , Zhou, X. , and Thomas, B. G. , 2013, “Measurement of Heat Flux in Dense Air-Mist Cooling—Part II: The Influence of Mist Characteristics on Steady-State Heat Transfer,” Exp. Therm. Fluid Sci., 44, pp. 161–173. [CrossRef]
Castillejos, E. A. H. , Herrera, M. A. , Hernández, C. I. , and Gutiérrez, M. E. P. , 2005, “Practical Productivity Gains—Towards a Better Understanding of Air-Mist Cooling in Thin Slab Continuous Casting,” Third International Congress of Steelmaking , Charlotte, NC, May 9–12, pp. 881–890.
Castillejos, E. A. H. , 2011, “Steel Continuous Casting Secondary Cooling—Aims, Air-Mist Nozzles and Laboratory Characterization,” The Roderick Guthrie Honorary Symposium on Process Metallurgy, Montreal, QC, Canada, June 6–9, pp. 397–405.
Montes, R. J. J. , Castillejos, E. A. H. , Gutiérrez, M. E. P. , and Herrera, G. M. A. , 2008, “Effect of the Operating Conditions of Air-Mists Nozzles on the Thermal Evolution of Continuously Cast Thin Slabs,” Can. Metall. Q., 47(2), pp. 187–204. [CrossRef]
Labergue, A. , Gradeck, M. , and Lemoine, F. , 2016, “Experimental Investigation of Spray Impingement Hydrodynamic on a Hot Surface at High Flow Rates Using Phase Doppler Analysis and Infrared Thermography,” Int. J. Heat Mass Transfer, 100, pp. 65–78. [CrossRef]
Guo, R. , Wu, J. , Fan, H. , and Zhan, X. , 2016, “The Effects of Spray Characteristics on Heat Transfer During Spray Quenching of Aluminum Alloy 2024,” Exp. Therm. Fluid Sci., 76, pp. 211–220. [CrossRef]
Dou, R. , Wen, Z. , and Zhou, G. , 2015, “Heat Transfer Characteristics of Water Spray Impinging on High Temperature Stainless Steel Plate With Finite Thickness,” Int. J. Heat Mass Transfer, 90, pp. 376–387. [CrossRef]
Puschmann, F. , and Specht, E. , 2004, “Transient Measurement of Heat Transfer in Metal Quenching With Atomized Sprays,” Exp. Therm. Fluid Sci., 28(6), pp. 607–615. [CrossRef]
Al-Ahmadi, H. M. , and Yao, S. C. , 2008, “Spray Cooling of High Temperature Metals Using High Mass Flux Industrial Nozzles,” Exp. Heat Transfer, 21(1), pp. 38–54. [CrossRef]
Sivakumar, D. , and Tropea, C. , 2002, “Splashing Impact of a Spray Onto a Liquid Film,” Phys. Fluids, 14(12), pp. L85–L88. [CrossRef]
De León B, M. , and Castillejos E, A. H. , 2015, “Physical and Mathematical Modeling of Thin Steel Slab Continuous Casting Secondary Cooling Zone Air-Mist Impingement,” Metall. Mater. Trans. B, 46(5), pp. 2028–2048. [CrossRef]
Kalantari, D. , and Tropea, C. , 2007, “Spray Impact Onto Flat and Rigid Walls: Empirical Characterization and Modelling,” Int. J. Multiphase Flow, 33(5), pp. 525–544. [CrossRef]
Panão, M. R. O. , and Moreira, A. L. N. , 2004, “Experimental Study of the Flow Regimes Resulting From the Impact of an Intermittent Gasoline Spray,” Exp. Fluids, 37(6), pp. 834–855. [CrossRef]
Minchaca M, J. I. , and Castillejos E, A. H. , 2011, “Size and Velocity Characteristics of Droplets Generated by Thin Steel Slab Continuous Casting Secondary Cooling Air-Mist Nozzles,” Metall. Mater. Trans. B, 42(3), pp. 500–515. [CrossRef]
Castanet, G. , Liénart, T. , and Lemoine, F. , 2009, “Dynamics and Temperature of Droplets Impacting Onto a Heated Wall,” Int. J. Heat Mass Transfer, 52(3–4), pp. 670–679. [CrossRef]
Dunand, P. , Castanet, G. , Gradeck, M. , Maillet, D. , and Lemoine, F. , 2013, “Energy Balance of Droplets Impinging Onto a Wall Heated Above the Leidenfrost Temperature,” Int. J. Heat Fluid Flow, 44, pp. 170–180. [CrossRef]
Bernardin, J. D. , Stebbins, C. J. , and Mudawar, I. , 1997, “Mapping of Impact and Heat Transfer Regimes of Water Drops Impinging on a Polished Surface,” Int. J. Heat Mass Transfer, 40(2), pp. 247–267. [CrossRef]
Yao, S. C. , and Cai, K. Y. , 1988, “The Dynamics and Leidenfrost Temperature of Drops Impacting on a Hot Surface at Small Angles,” Exp. Therm. Fluid Sci., 1(4), pp. 363–371. [CrossRef]
Wachters, L. H. J. , and Westerling, N. A. , 1966, “The Heat Transfer From a Hot Wall to Impinging Water Drops in the Spheroidal State,” Chem. Eng. Sci., 21(11), pp. 1047–1056. [CrossRef]
Moita, A. S. , and Moreira, A. L. N. , 2007, “Drop Impacts Onto Cold and Heated Rigid Surfaces: Morphological Comparisons, Disintegration Limits and Secondary Atomization,” Int. J. Heat Fluid Flow, 28(4), pp. 735–752. [CrossRef]
Jung, J. , Jeong, S. , and Kim, H. , 2016, “Investigation of Single-Droplet/Wall Collision Heat Transfer Characteristics Using Infrared Thermometry,” Int. J. Heat Mass Transfer, 92, pp. 774–783. [CrossRef]
Fujimoto, H. , Oku, Y. , Ogihara, T. , and Takuda, H. , 2010, “Hydrodynamics and Boiling Phenomena of Water Droplets Impinging on Hot Solid,” Int. J. Multiphase Flow, 36(8), pp. 620–642. [CrossRef]
Cossali, G. E. , Marengo, M. , and Santini, M. , 2008, “Thermally Induced Secondary Drop Atomisation by Single Drop Impact Onto Heated Surfaces,” Int. J. Heat Fluid Flow, 29(1), pp. 167–177. [CrossRef]
Cossali, G. E. , Marengo, M. , and Santini, M. , 2005, “Secondary Atomisation Produced by Single Drop Vertical Impacts Onto Heated Surfaces,” Exp. Therm. Fluid Sci., 29(8), pp. 937–946. [CrossRef]
Bertola, V. , 2015, “An Impact Regime Map for Water Drops Impacting on Heated Surfaces,” Int. J. Heat Mass Transfer, 85, pp. 430–437. [CrossRef]
Castillejos, E. A. H. , 2014, “INCONV.f90, Computer Program for Solving the Induction Conduction Problem in the Probe Assembly,” CINVESTAV, Unidad Saltillo, Mexico.
Park, S. W. , and Lee, C. S. , 2004, “Macroscopic and Microscopic Characteristics of a Fuel Spray Impinged on the Wall,” Exp. Fluids, 37(6), pp. 745–762. [CrossRef]
Mejía García, M. E., 2012, “Aspectos de la dinámica de gotas en nieblas con alta densidad de impacto,” M.Sc. thesis, CINVESTAV, Unidad Saltillo, Coahuila, México.
Brown, D., 2009, “Tracker Video Analysis and Modeling Tool,” Tracker, CA, accessed Dec. 27, 2017, http://physlets.org/tracker/
ImageJ, 2014, “National Institute of Health, Image Processing and Analysis in JAVA,” Wayne Rasband, NIH Image, Bethesda, MD, accessed Dec. 27, 2017, http://imagej.nih.gov/ij/
Kline, S. J. , and McClintock, F. A. , 1953, “Describing Uncertainties in Single Sample Experiments,” Mech. Eng., 75(1), pp. 3–8.
Toda, S. , 1972, “A Study of Mist Cooling (2nd Report: Theory of Mist Cooling and Its Fundamental Experiments),” Heat Transfer Jpn. Res., 37(1), pp. 1–44.
Minchaca, M. J. I. , Castillejos, E. A. H. , and Murphy, S. , 2010, “Fluid Dynamics of Thin Steel Slab Continuous Casting Secondary Cooling Zone Air Mists,” ILASS-Americas 22nd Annual Conference on Liquid Atomization and Spray Systems (ILASS), Cincinnati, OH, May 16–19, pp. 1–17.
Rein, M. , 1993, “Phenomena of Liquid Drop Impact on Solid and Liquid Surfaces,” Fluid Dyn. Res., 12(2), pp. 61–93. [CrossRef]
Mezbah, U. , Yoshida, S. , Someya, S. , and Koji, O. , 2007, “Visualization of Transient Interaction Phenomena Between Droplets and Hot Walls Around Leidenfrost Temperature for SUS304,” International Conference on Mechanical Engineering, Dhaka, Bangladesh, Dec. 29–31, pp. 1–5.

Figures

Grahic Jump Location
Fig. 1

(a) Heat flux measuring probe, (b) schematic of probe positions, nominal drop impingement angles and camera orientation, (c) schematic of experimental setup for measuring steady-state heat flux and visualizing drop impingement phenomena, and (d) photograph of system components placed around the Pt sample

Grahic Jump Location
Fig. 2

Boiling curves for set-point temperature loops encompassing 100–1200–100 °C and for different nozzle operating conditions and x-positions along the major axis of the mist footprint: (a) 0 m, (b) 0.125 m, and (c) 0.150 m

Grahic Jump Location
Fig. 3

Characteristic flow structures observed during mist/spray heat extraction in the regimes of: (a) SPhC, (b) NB, (c) TB, and (d) FB. The images were obtained with W = 0.076 L/s, pa = 189 kPa, at x = 0 m.

Grahic Jump Location
Fig. 4

Characteristics flow structures observed during mist/spray heat extraction in the regimes of: (a) SPhC, (b) NB, (c) TB, and (d) FB. The images were obtained with W = 0.076 L/s, pa = 189 kPa, at x = 0.1215 m. The impingement surface appears inclined because as shown in Fig. 2(b) the camera was tilted to orient it along the nominal direction of primary drops.

Grahic Jump Location
Fig. 5

Comparison between measured and regression calculated heat fluxes for: (a) single phase convection and NB, (b) TB, and (c) FB. Results obtained with a W19822 nozzle operating over the wide range of conditions and positions indicated in Table 2, and with Tw leading to different boiling regimes.

Grahic Jump Location
Fig. 6

Measured and regression estimated boiling curves for the positions and conditions indicated

Grahic Jump Location
Fig. 7

Predominance area diagram of impact regimes of water drops in mists impinging upon a hot surface at temperatures ranging from ∼60 to 1200 °C, results of observations at x = 0 and 0.125 m are included

Grahic Jump Location
Fig. 8

Side view images of different drop impact modes indicating the particular drop—dd, uz, Wez—and surface—Tw, −q—conditions involved. (a) Stick: 265 μm, 1.1 m/s, 4.5, 580 °C, 1.8 MW/m2; (b) Spread: 126 μm, 3.1 m/s, 16.3, 62 °C, 2.5 MW/m2; (c) Rebound: 181 μm, 4.2 m/s, 44.5, 116 °C, 8.1 MW/m2.

Grahic Jump Location
Fig. 9

Bar chart of relative occurrence of the impact modes of droplets observed at central and at a lateral position of the mist footprint, for the temperature range where they occurred

Grahic Jump Location
Fig. 10

Side view images of splash with fine atomization indicating the particular drop—dd, uz, Wez—and surface—Tw, −q—conditions involved. (a) Low temperature: 149 μm, 23.3 m/s, 933, 105.3 °C, 6.2 MW/m2; (b) High temperature: 176 μm, 18.5 m/s, 834, 1144 °C, 5 MW/m2.

Grahic Jump Location
Fig. 13

Impact of dense parcels at different x footprint positions: (a) 0 m and (b) 0.125 m, the respective Tw are given. W = 0.076 L/s, pa = 189 kPa.

Grahic Jump Location
Fig. 12

Side view images of splash with jet atomization indicating the particular drop—dd, uz, Wez—and surface—Tw, −q—conditions involved. (a) Low temperature: 1256 μm, 16.5 m/s, 4715, 61.6 °C, 2.5 MW/m2; (b) High temperature : 889 μm, 19.8 m/s, 4799, 1144 °C, 5 MW/m2.

Grahic Jump Location
Fig. 11

Side view images of splash with crown atomization indicating the particular drop—dd, uz, Wez—and surface—Tw, −q—conditions involved: 247 μm, 15.7 m/s, 832; 90 °C, 7.2 MW/m2

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In