Related Experiment Video
Updated: Oct 18, 2025
07:06
Continuous Flow Chemistry: Reaction of Diphenyldiazomethane with p-Nitrobenzoic Acid
Published on: November 15, 2017
11.6K
Improving heat and mass transfer rates through continuous drop-wise condensation
Ali Alshehri1,2,3, Jonathan P Rothstein4, H Pirouz Kavehpour5
1Mechanical and Aerospace Engineering Department, University of California, Los Angeles, CA, 90095, USA. alshehri@kfupm.edu.sa.
Scientific Reports
|October 5, 2021
Summary
Continuous drop-wise condensation (DWC) overcomes hydrophobic surface limitations by using jet impingement to control droplet size. This novel method significantly enhances condensation rates and alleviates non-condensable gas effects for improved dehumidification.
Area of Science:
- Heat Transfer
- Fluid Dynamics
- Chemical Engineering
Background:
- Drop-wise condensation (DWC) is a critical vapor condensation technology, but its efficiency is limited by droplet size and shedding frequency.
- The presence of non-condensable gases (NCG) severely reduces condensation rates in traditional DWC.
- Existing DWC methods often rely on specialized hydrophobic surfaces, posing manufacturing and durability challenges.
Purpose of the Study:
- To introduce a continuous drop-wise condensation technique that eliminates the need for hydrophobic surfaces.
- To investigate the use of jet impingement to control droplet size and shedding dynamics.
- To assess the impact of this new method on condensation efficiency, particularly in the presence of non-condensable gases.
Main Methods:
- Developed a continuous drop-wise condensation system utilizing jet impingement.
- Focused on manipulating the force required to shed droplets rather than surface properties.
- Tuned jet parameters (e.g., flow rate, pressure) to control droplet size and shedding frequency.
Main Results:
- Demonstrated effective control over shed droplet size by adjusting jet parameters.
- Observed a significant alleviation of the negative effects of non-condensable gases.
- Achieved a multi-fold improvement in the mass transfer compactness factor compared to existing technologies.
Conclusions:
- Continuous drop-wise condensation using jet impingement offers a viable alternative to surface-dependent methods.
- This technique effectively manages droplet dynamics and mitigates non-condensable gas interference.
- The approach shows substantial promise for highly efficient dehumidification and other condensation-based processes.
Related Concept Videos
01:12Precipitation Processes
777
The experimental conditions in a gravimetric analysis should be optimized to maximize the particle size and purity of the obtained precipitate. Ideally, the concentration of the precipitating reagent should be low with effective stirring to maintain low relative supersaturation for the growth of large crystals. In homogeneous precipitation, the precipitant is slowly generated by a chemical reaction in the solution to avoid local reagent excesses. For example, urea decomposes gradually to...
777
01:01Distillation: Vapor–Liquid Equilibria
3.3K
Distillation is a separation technique that takes advantage of the boiling point properties of disparate elements in a mixture. To perform distillation, we begin by heating a miscible mixture of two liquids with a significant difference in boiling points (at least 20°C). As the solution heats up and reaches the bubble point of the more volatile component, some molecules of the more volatile component transition into the gas phase and travel upward into the condenser, which is a glass tube...
3.3K
00:52Washing, Drying, and Ignition of Precipitates
1.4K
After filtration, the precipitate is washed to remove coprecipitated impurities and any remaining mother liquor. Colloidal precipitates, such as silver chloride, are washed with an electrolyte (such as dilute nitric acid) to prevent the peptization of the precipitate. In the case of slightly soluble precipitates, the wash solution contains a common ion to reduce solubility. Lead sulfate, which is slightly soluble in water, is washed with dilute sulfuric acid. Similarly, wash solutions may be...
1.4K
01:14Mechanisms of Heat Transfer I
5.0K
Just as interesting as the effects of heat transfer on a system are the methods by which the heat transfer occur. Whenever there is a temperature difference, heat transfer occurs. It may occur rapidly, such as through a cooking pan, or slowly, such as through the walls of a picnic ice box. So many processes involve heat transfer that it is hard to imagine a situation where no heat transfer occurs. Yet, every heat transfer takes place by only three methods: conduction, convection, and radiation.
5.0K
01:20Mechanisms of Heat Transfer II
3.7K
In convection, thermal energy is carried by the large-scale flow of matter. Ocean currents and large-scale atmospheric circulation, which result from the buoyancy of warm air and water, transfer hot air from the tropics toward the poles and cold air from the poles toward the tropics. The Earth’s rotation interacts with those flows, causing the observed eastward flow of air in the temperate zones. Convection dominates heat transfer by air, and the amount of available space for the airflow...
3.7K
01:10Recrystallization: Solid–Solution Equilibria
1.5K
Recrystallization is a purification technique used to separate impurities from solid compounds. In this technique, no chemical reactions occur. Instead, it exploits physical properties only, specifically, the solubility differences between the desired compound and impurities, either at a single temperature or at different temperatures, and under other selected conditions. The solid-solution equilibrium (solubility equilibrium) of each component in the solution represents a binary phase...
1.5K