The Effect of Dissolving Gases or Solids in Water Droplets Boiling on a Hot Surface

2001 ◽  
Vol 123 (4) ◽  
pp. 719-728 ◽  
Author(s):  
Qiang Cui ◽  
Sanjeev Chandra ◽  
Susan McCahan
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
Sodium Bicarbonate ◽  
Sodium Carbonate ◽  
Bubble Formation ◽  
Nucleate Boiling ◽  
Water Droplets ◽  
Dissolved Carbon ◽  
Dissolved Carbon Dioxide ◽  
Dissolved Salts

We conducted experiments on the effect of dissolving either a gas (carbon dioxide) or a solid salt (sodium carbonate or sodium bicarbonate) in water droplets boiling on a hot stainless steel surface. Substrate temperatures were varied from 100°C to 300°C. We recorded the boiling of droplets with a video system, and photographed droplet impact using short-duration flash photography. At surface temperatures that were too low to initiate nucleate boiling, dissolved salts were found to reduce the evaporation rate since they lower the vapor pressure of water. Dissolved gas had the opposite effect: it came out of solution and formed bubbles in the liquid, enhancing evaporation. In the nucleate boiling regime dissolved carbon dioxide enhanced heat transfer by a small amount. However, sodium carbonate prevented coalescence of vapor bubbles and produced foaming in the droplet, greatly enhancing heat transfer and reducing the droplet lifetime to approximately half that of a pure water drop. Sodium bicarbonate, which decomposes to give carbon dioxide and sodium carbonate when heated, produced an even larger enhancement of heat transfer. When the surface temperature was raised above the Leidenfrost temperature of water, droplets went into film boiling and bounced off the surface following impact. Dissolved carbon dioxide was found to suppress heterogeneous bubble formation in the droplet during impact. However, dissolved salts promoted bubble formation and led to droplet break-up during impact.

Impact of Dursban and Abate on Microbial Numbers and Some Chemical Properties of Standing Ponds

1975 ◽  
Vol 10 (1) ◽  
pp. 33-41 ◽  
Author(s):  
J. Butcher ◽  
M. Boyer ◽  
CD. Fowle
Keyword(s):  
Carbon Dioxide ◽  
Active Ingredient ◽  
Algal Blooms ◽  
Chemical Properties ◽  
Total Carbon ◽  
Dissolved Carbon ◽  
Photosynthetic Productivity ◽  
Dissolved Carbon Dioxide ◽  
Microbial Numbers

Abstract Eleven small ponds, lined with polyethylene, were used to assess the consequences of applications of *DursbanR at 0.004, 0.030, 0.100 and 1.000 ppm and AbateR at 0.025 and 0.100 ppm active ingredient. The treated ponds showed a more pronounced long-term increase in pH and dissolved oxygen and decreasing total and dissolved carbon dioxide in comparison with untreated ponds. Algal blooms were of longer duration in treated ponds than in controls. Total photosynthetic productivity was higher in treated ponds but bacterial numbers did not change significantly. Photosynthetic productivity was estimated by following the changes in total carbon dioxide.

scholarly journals Defining features in the kinetics of sodium carbonate-bicarbonate solution carbonization and the quality of the resulting sodium bicarbonate crystals

2021 ◽  
Vol 4 (10(112)) ◽  
pp. 38-44
Author(s):  
Mykola Porokhnia ◽  
Musii Tseitlin ◽  
Svitlana Bukhkalo ◽  
Vladimir Panasenko ◽  
Tetiana Novozhylova
Keyword(s):  
Carbon Dioxide ◽  
Sodium Bicarbonate ◽  
Sodium Carbonate ◽  
Diffusion Resistance ◽  
Crystal Formation ◽  
Gas Velocity ◽  
Laboratory Equipment ◽  
Gas Consumption ◽  
Kinetics Of

This paper reports a study into the influence of temperature and gas consumption on the carbonization kinetics (saturation with carbon dioxide) of sodium carbonate-bicarbonate solution. The study also examined the quality and speed of crystal formation in this process. This research is predetermined by the environmental problems faced by modern enterprises that produce purified sodium bicarbonate – an insufficient degree of carbonization and, as a result, excessive air pollution with carbon dioxide, which did not participate in the reaction during the process. This study addresses these particular issues. As a result of using specialized laboratory equipment, it was found that an increase in the absorbent temperature from 79 to 85 °C leads to a decrease in the maximum degree of carbonization of the solution from 64 to 59 %. In contrast, the quality of the resulting sodium bicarbonate crystals improves but only in the range from 79 to 82 °C. With a further increase in temperature, the quality stabilizes. It is shown that the carbonization rate increases with increasing specific consumption of the absorbent (carbon dioxide) and is characterized by a negative correlation with the value of oversaturation of the absorbent in terms of NaНCO3. The quality of sodium bicarbonate crystals decreases with increasing gas velocity. Thus, it was reasonable to assume that the established dependence of the kinetics of carbonization of Na2CO3 and NaНCO3 solution on the gas velocity in the apparatus is explained by the inhibition of СО2 absorption, which is caused by the diffusion resistance of sodium bicarbonate crystallization. To improve the quality of crystals and the productivity of carbonization by reducing the supersaturation in terms of NaНCO3, it is recommended to introduce a seed crystal in the zone of binding of crystals in the carbonization columns.

scholarly journals FORMATION CONDITIONS OF GROUNDWATER OF THE UPPER JURASSIC OF THE CENTRAL REGIONS OF THE ZAURAL MEGAMONOCLYSIS

2021 ◽  
Vol 2 (1) ◽  
pp. 181-190
Author(s):  
Dmitry A. Novikov ◽  
Aleksandr N. Pyrayev ◽  
Fedor F. Dultsev ◽  
Anatoliy V. Chernykh ◽  
Svetlana V. Bakustina ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Isotopic Composition ◽  
Upper Jurassic ◽  
Biogenic Origin ◽  
Dissolved Carbon ◽  
Dissolved Carbon Dioxide ◽  
Oxygen And Hydrogen Isotopes ◽  
Central Regions ◽  
First Results ◽  
Formation Conditions

The article presents the first results of complex isotope-hydrogeochemical studies of reservoir waters of the Upper Jurassic deposits of the central regions of the Zaural megamonoclysis. It was shown that most waters have a narrow distribution of oxygen and hydrogen isotopes (δD from -103.2 to -85.6 ‰ and δO from -15.4 to -12.9 ‰). Some of them have pronounced excursions on the isotopic composition, which indicates a difference in their genesis: from condensate to mixed with ancient infiltrogenic. The isotopic composition of carbon of water-dissolved carbon dioxide (δС from -41.6 to -16.3 ‰) indicates its biogenic origin and the possibility of interstratal flows from overlying horizons.

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