Pool Boiling Heat Transfer in Aqueous Solutions of an Anionic Surfactant

2000 ◽  
Vol 122 (4) ◽  
pp. 708-715 ◽  
Author(s):  
V. M. Wasekar ◽  
R. M. Manglik
Keyword(s):  
Anionic Surfactant ◽  
Pure Water ◽  
Pool Boiling ◽  
Sodium Dodecyl ◽  
Dynamic Surface Tension ◽  
Nucleate Boiling ◽  
Optimum Level ◽  
Lauryl Sulfate ◽  
Dynamic Surface ◽  
Influence Of Temperature On

Saturated nucleate pool boiling of aqueous surfactant solutions on a horizontal cylindrical heater has been experimentally investigated. Sodium dodecyl or lauryl sulfate (SDS or SLS), an anionic surfactant, is employed. Boiling performance, relative to that for pure water, is found to be enhanced significantly by the presence of SDS, with an early onset of nucleate boiling. An optimum level of enhancement is observed in solutions at or near critical micelle concentration of the surfactant; the enhancement, however, decreases considerably in higher concentration solutions. The dynamic surface tension measurements indicate a substantial influence of temperature on the overall adsorption isotherm. The diffusion kinetics of surfactant molecules and micelles is, therefore, expected to be quite different at boiling temperature than at room temperature. This greatly modifies the boiling mechanism that is generally characterized by the formation of smaller-size bubbles with increased departure frequencies, and a decreased tendency to coalesce which causes considerable foaming. [S0022-1481(00)00704-0]

Pool Boiling Heat Transfer in Aqueous Surfactant Solutions

1999 ◽  
Author(s):  
Vivek M. Wasekar ◽  
Raj M. Manglik
Keyword(s):  
Pure Water ◽  
Pool Boiling ◽  
Sodium Dodecyl ◽  
Dynamic Surface Tension ◽  
Nucleate Boiling ◽  
Optimum Level ◽  
Lauryl Sulfate ◽  
Dynamic Surface ◽  
Surfactant Solutions ◽  
Influence Of Temperature On

Abstract Saturated, nucleate pool boiling of aqueous surfactant solutions on a horizontal, cylindrical heater has been experimentally investigated. Sodium dodecyl or lauryl sulfate (SDS or SLS), an anionic surfactant is employed. Boiling performance, relative to that for pure water, is found to be enhanced significantly by the presence of SDS, with an early onset of nucleate boiling. An optimum level of enhancement is observed in solutions at or near critical micelle concentration of the surfactant; the enhancement decreases considerably in higher concentration solutions. The dynamic surface tension measurements indicate a considerable influence of temperature on the overall adsorption isotherm. The diffusion kinetics of surfactant molecules and micelles is, therefore, expected to be quite different at boiling temperature than at room temperature. This greatly modifies the boiling mechanism, that is generally characterized by the formation of smaller-size bubbles with increased departure frequencies, and a decreased tendency to coalesce which causes considerable foaming.

Additive Adsorption and Interfacial Characteristics of Nucleate Pool Boiling in Aqueous Surfactant Solutions

2005 ◽  
Vol 127 (7) ◽  
pp. 684-691 ◽  
Author(s):  
Juntao Zhang ◽  
Raj M. Manglik
Keyword(s):  
Contact Angle ◽  
Pure Water ◽  
Pool Boiling ◽  
Dynamic Surface Tension ◽  
Nucleate Pool Boiling ◽  
Dynamic Surface ◽  
Wetting Contact Angle ◽  
Optimum Heat ◽  
Adsorption Desorption ◽  
And Control

Interfacial phenomena and ebullient dynamics in saturated nucleate pool boiling of aqueous solutions of three surfactants that have different molecular weight and ionic nature are experimentally investigated. The additive molecular mobility at interfaces manifests in a dynamic surface tension behavior (surfactant adsorption–desorption at the liquid–vapor interface), and varying surface wetting (contact angle) with concentration (surfactant physisorption at the solid–liquid interface). This tends to change, enhance, and control the boiling behavior significantly, and an optimum heat transfer enhancement is obtained in solutions at or near the critical micelle concentration (CMC) of the surfactant. Furthermore, wettability (contact angle) is observed to be a function of the molecular makeup of the reagent, and shows distinct regions of change along the adsorption isotherm that are associated with the aggregation mode of adsorbed ions at the solid–water interface. This distinguishably alters the ebullience from not only that in pure water, but also between pre- and post-CMC solutions. Increased wetting tends to suppress nucleation and bubble growth, thereby weakening the boiling process.

Experimental Investigation of Low Weber Number Post-Impact Drop Spreading on Solid Substrates

2010 ◽  
Author(s):  
Milind A. Jog ◽  
Raj M. Manglik
Keyword(s):  
Surface Tension ◽  
High Speed ◽  
Pure Water ◽  
Surfactant Solution ◽  
Video Camera ◽  
Dynamic Surface Tension ◽  
Temporal Variations ◽  
Dynamic Surface ◽  
Post Impact ◽  
Triton X

The post-impact spreading and recoil behaviors of droplets of pure liquids (water and ethanol) and aqueous solution of Triton X-100 (a surfactant) on a dry horizontal hydrophilic (glass) substrate are investigated for low Weber numbers. The evolution of drop shape during spreading and recoil are captured using a high-speed (4,000 frames per second) digital video camera. Digital image-processing was used to determine the spread and height of the liquid film on the surface from each frame. Unlike pure liquids, the liquid-gas interfacial tension for surfactant solution is a function of surface age, where surface tension is that of the solvent at zero time and then reaches an equilibrium value with increasing surface age. Furthermore, the equilibrium surface tension is a function of the surfactant concentration, which decreases from that of the solvent at zero concentration to that at the critical micelle concentration (CMC), and remains essentially constant thereafter. The surface tension of aqueous Triton X-100 solution varies from that of pure water to nearly that of ethanol. As such the comparison of transient droplet-impact-spreading-recoil behavior of the three liquids, or their temporal variations of the spread and the flattening factor, provides a basis for understanding the role of dynamic surface tension and surface wettability.

Study on Foaming Properties of Sodium Dodecyl Sulfate for Textile Foam Dyeing and Finishing

2011 ◽  
Vol 332-334 ◽  
pp. 1515-1519 ◽  
Author(s):  
Ke Li ◽  
Jian Fei Zhang ◽  
Qiu Jin Li
Keyword(s):  
Foam Stability ◽  
Sodium Dodecyl ◽  
Dynamic Surface Tension ◽  
Foaming Properties ◽  
Textile Processing ◽  
Dynamic Surface ◽  
Novel Approach ◽  
Foam Properties ◽  
Save Energy ◽  
The Relationship

Foam dyeing and finishing is a novel approach for textile processing, which can save energy and reduce the quantity of waster water. Frother plays an important role in foam dyeing and finishing systems. In this paper, the foaming properties of SDS were investigated for the purpose of application of foaming systems in fabric dyeing and finishing. The influence of SDS on foam properties was studied by measuring foamability, foam stability, equilibrium and dynamic surface tension, surface viscosity bubble size and bubble uniformity. At the same time, the relationship between foam apparent performance and microcosmic mechanism was also analyzed. The research will benefits the future study on the application of foam technique to the field of textile.

On the Mechanism of Pool Boiling Critical Heat Flux Enhancement in Nanofluids

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
Hyungdae Kim ◽  
Ho Seon Ahn ◽  
Moo Hwan Kim
Keyword(s):  
Heat Flux ◽  
Critical Heat Flux ◽  
Heated Surface ◽  
Pure Water ◽  
Pool Boiling ◽  
Nucleate Boiling ◽  
Titania Nanoparticles ◽  
Nanoparticle Layer ◽  
Wall Superheat ◽  
Dry Spot

The pool boiling characteristics of water-based nanofluids with alumina and titania nanoparticles of 0.01 vol % were investigated on a thermally heated disk heater at saturated temperature and atmospheric pressure. The results confirmed the findings of previous studies that nanofluids can significantly enhance the critical heat flux (CHF), resulting in a large increase in the wall superheat. It was found that some nanoparticles deposit on the heater surface during nucleate boiling, and the surface modification due to the deposition results in the same magnitude of CHF enhancement in pure water as for nanofluids. Subsequent to the boiling experiments, the interfacial properties of the heater surfaces were examined using dynamic wetting of an evaporating water droplet. As the surface temperature increased, the evaporating meniscus on the clean surface suddenly receded toward the liquid due to the evaporation recoil force on the liquid-vapor interface, but the nanoparticle-fouled surface exhibited stable wetting of the liquid meniscus even at a remarkably higher wall superheat. The heat flux gain attainable due to the improved wetting of the evaporating meniscus on the fouled surface showed good agreement with the CHF enhancement during nanofluid boiling. It is supposed that the nanoparticle layer increases the stability of the evaporating microlayer underneath a bubble growing on a heated surface and thus the irreversible growth of a hot/dry spot is inhibited even at a high wall superheat, resulting in the CHF enhancement observed when boiling nanofluids.

Experimental Study of Surfactant Effects on Pool Boiling Heat Transfer

1990 ◽  
Vol 112 (1) ◽  
pp. 207-212 ◽  
Author(s):  
Ying Liang Tzan ◽  
Yu Min Yang
Keyword(s):  
Heat Transfer ◽  
Binary Mixtures ◽  
Boiling Heat Transfer ◽  
Sodium Lauryl Sulfate ◽  
Pool Boiling ◽  
Nucleate Boiling ◽  
Additive Concentration ◽  
Lauryl Sulfate ◽  
Diffusion Effect ◽  
Nucleate Boiling Heat Transfer

In the first part of this work, nucleate boiling of aqueous solutions of sodium lauryl sulfate (SLS) over relatively wide ranges of concentration and heat flux was carried out in a pool boiling apparatus. The experimental results show that a small amount of surface active additive makes the nucleate boiling heat transfer coefficient h considerably higher, and that there is an optimum additive concentration for higher heat fluxes. Beyond this optimum point, further increase in additive concentration makes h lower. In the second part of this work, nucleate boiling heat transfer rate for n-propanol-water binary mixtures with various amounts of sodium lauryl sulfate were measured in the same pool boiling apparatus. The importance of the mass diffusion effect, which is caused by preferential evaporation of the more volatile component at the vapor-liquid interface on the boiling of the binary mixture, has been confirmed. However, it is shown that the effect exerted by the addition of a surfactant dominates over the mass diffusion effect in dilute binary mixtures.

Effect of Ethoxylation and Molecular Weight of Cationic Surfactants on Nucleate Boiling in Aqueous Solutions

2004 ◽  
Vol 126 (1) ◽  
pp. 34-42 ◽  
Author(s):  
Juntao Zhang ◽  
Raj M. Manglik
Keyword(s):  
Molecular Weight ◽  
Surface Tension ◽  
Aqueous Solutions ◽  
Cationic Surfactants ◽  
Bubble Dynamics ◽  
Surfactant Solution ◽  
Dynamic Surface Tension ◽  
Nucleate Boiling ◽  
Dynamic Surface ◽  
Reduce Surface Tension

Saturated, nucleate pool boiling on a horizontal, cylindrical heater and the associated bubble dynamics in aqueous solutions of cationic surfactants of different molecular weight and ethoxylation or ethylene oxide (EO) content, are experimentally investigated. Boiling curves qw″∝ΔTsat for different concentrations and photographic records of the salient features of the ebullient behavior are presented, along with a characterization of interfacial properties (surface tension and contact angle). The surfactant additive significantly alters the nucleate boiling in water and enhances the heat transfer. The enhancement increases with concentration, with an optimum obtained in solutions at or near the critical micelle concentration (c.m.c.) of the surfactant. The photographic and visual observations indicate a markedly different boiling behavior than that of water, as well as between pre- and post-c.m.c. solutions. A lower molecular weight surfactant tends to reduce surface tension faster, and show better enhancement performance than its higher molecular weight counterpart. With EO groups in its molecular chain the surfactant solution becomes more hydrophilic, and the higher wettability tends to suppress nucleation, thereby weakening the boiling process. Also, enhancement in pre-micellar solutions is shown to depend on the dynamic surface tension, and the number of EO groups in and molecular weight of the surfactant.

Comparisons of Aqueous Surfactant Solutions for Nucleate Pool Boiling

2016 ◽  
Author(s):  
Birce Dikici ◽  
Basim Q. A. Al-Sukaini
Keyword(s):  
Heat Transfer ◽  
Boiling Heat Transfer ◽  
Pure Water ◽  
Pool Boiling ◽  
Lauryl Sulfate ◽  
Nucleate Pool Boiling ◽  
Transfer Enhancement ◽  
Surfactant Solutions ◽  
Boiling Heat Transfer Coefficient ◽  
Important Possibility

In this study, nucleate pool boiling of surfactant solutions are investigated. The surfactants chosen for the study are an ionic sodium lauryl sulfate (SLS), nonionic ECOSURF™ EH-14, and nonionic ECOSURF™ SA-9. It is observed that adding a small amount of surfactant alters the water boiling phenomenon considerably. Boiling curves for different concentrations are shifted to the left. The wall temperature dropped with an increase in the concentration of aqueous surfactant solutions. Also, it is found that the boiling heat transfer enhancement of SLS is higher than that of EH-14 and SA-9 compared to water. Boiling heat transfer coefficient (h) enhancements compared to water are 46%, 30%, and 21%. (for SLS, for EH-14 and for SA-9 respectively) Boiling visualization shows that boiling with surfactant solutions compared with that in pure water is more vigorous. Bubbles are smaller, activate continuously, and collapse quickly. Also, the bubble departure frequency is observed to be higher than that of pure water. Results prove that there is an important possibility to enhance the boiling application processes by environmentally friendly EH-14, and SA-9 additives. Experimentation can be extended for searching other surfactants in order to find their most efficient quantity in water for boiling heat transfer.

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