Critical Conditions for Secondary Droplets Generated by Droplets Colliding Walls With Different Angles

2020 ◽  
Author(s):  
Yikai Wu ◽  
Wenxuan Ju ◽  
Yusheng Liu ◽  
Fulong Zhao ◽  
Sichao Tan
Keyword(s):  
Phase Change ◽  
Separation Efficiency ◽  
Three Dimensional ◽  
Gravity Separation ◽  
Critical Conditions ◽  
Vapor Flow ◽  
Change Model ◽  
Water Separation ◽  
Critical Separation ◽  
Droplet Phase

Abstract The single droplet phase change model during motion is developed based on the phenomena description and mechanism comprehension, which including the droplet phase change model as well as the droplet motion model. Then, the calculation of the droplet phase change characteristics during moving in the uniform flow in the gravity separation space is conducted. The results show that when the droplet are evaporating during its moving, the radius will decrease continuously and it will be carried more easily by the steam vapor, which will lead to the larger separation radii of the droplets and the reduced the gravity separation efficiency. In addition, this paper shows the three-dimensional map for the critical separation over the pressure difference and the steam vapor flow velocity, which can contribute to forecast the influence of the droplet phase change on the separation characteristics. The results can be applied in the design of the steam-water separation plants.

scholarly journals Superwetting Polymeric Three Dimensional (3D) Porous Materials for Oil/Water Separation: A Review

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 806 ◽  
Author(s):  
Yihao Guan ◽  
Fangqin Cheng ◽  
Zihe Pan
Keyword(s):  
Porous Materials ◽  
Oil Spills ◽  
Mechanical Stability ◽  
Separation Efficiency ◽  
Three Dimensional ◽  
High Porosity ◽  
Water Separation ◽  
Term Operation ◽  
Oil Water Separation ◽  
Oil Water

Oil spills and the emission of oily wastewater have triggered serious water pollution and environment problems. Effectively separating oil and water is a world-wide challenge and extensive efforts have been made to solve this issue. Interfacial super-wetting separation materials e.g., sponge, foams, and aerogels with high porosity tunable pore structures, are regarded as effective media to selectively remove oil and water. This review article reports the latest progress of polymeric three dimensional porous materials (3D-PMs) with super wettability to separate oil/water mixtures. The theories on developing super-wetting porous surfaces and the effects of wettability on oil/water separation have been discussed. The typical 3D porous structures (e.g., sponge, foam, and aerogel), commonly used polymers, and the most reported techniques involved in developing desired porous networks have been reviewed. The performances of 3D-PMs such as oil/water separation efficiency, elasticity, and mechanical stability are discussed. Additionally, the current challenges in the fabrication and long-term operation of super-wetting 3D-PMs in oil/water separation have also been introduced.

Primary Investigation on the Mechanism of Gravity Separation of the Droplets in the Steam Flow Field

2010 ◽  
Author(s):  
Jinyi Zhang ◽  
Hanliang Bo
Keyword(s):  
Flow Field ◽  
Separation Efficiency ◽  
Droplet Diameter ◽  
Gravity Separation ◽  
Qualitative Description ◽  
Steam Flow ◽  
Vapor Flow ◽  
Single Drop ◽  
Physical Description ◽  
The Relationship

A physical description of the formative cause and the ascension height of droplets is given according to the mechanism of gravity separation of the droplets in the steam flow field. In order to analyze the relationship between the height of gravity separation space and steam wetness, the dynamic single-drop model based on some simplified hypotheses is adopted, a comparison between the calculations and the experimental data is carried out. Based on this model and its analysis, the effects of the gravity separation space height, the velocity of the vapor flow, the droplet diameter as well as the initial velocity on the gravity separation efficiency are discussed in details. The qualitative description and analysis for the mechanism of gravity separation of the droplets in the steam flow field in this paper lays the groundwork for the qualitative analysis of the dynamic single-drop model.

scholarly journals A three-dimensional polyoxometalate/graphene aerogel as a highly efficient and recyclable absorbent for oil/water separation

2021 ◽  
Vol 36 (1) ◽  
pp. 189-197
Author(s):  
Sen Wang ◽  
Xiao Wang ◽  
Xiao-yu Shi ◽  
Cai-xia Meng ◽  
Cheng-lin Sun ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Graphene Aerogel ◽  
Water Separation ◽  
Highly Efficient ◽  
Oil Water Separation ◽  
Oil Water

scholarly journals Numerical Study toward Optimization of Spray Drying in a Novel Radial Multizone Dryer

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1233
Author(s):  
Umair Jamil Ur Rahman ◽  
Artur Krzysztof Pozarlik ◽  
Thomas Tourneur ◽  
Axel de Broqueville ◽  
Juray De Wilde ◽  
...  
Keyword(s):  
Spray Drying ◽  
Droplet Size ◽  
Separation Efficiency ◽  
Numerical Study ◽  
Three Dimensional ◽  
Droplet Size Distribution ◽  
Vortex Chamber ◽  
Temperature Pattern ◽  
Multiphase Model ◽  
Drying Technology

In this paper, an intensified spray-drying process in a novel Radial Multizone Dryer (RMD) is analyzed by means of CFD. A three-dimensional Eulerian–Lagrangian multiphase model is applied to investigate the effect of solids outlet location, relative hot/cold airflow ratio, and droplet size on heat and mass transfer characteristics, G-acceleration, residence time, and separation efficiency of the product. The results indicate that the temperature pattern in the dryer is dependent on the solids outlet location. A stable, symmetric spray behavior with maximum evaporation in the hot zone is observed when the solids outlet is placed at the periphery of the vortex chamber. The maximum product separation efficiency (85 wt %) is obtained by applying high G-acceleration (at relative hot/cold ratio of 0.75) and narrow droplet size distribution (45–70 µm). The separation of different sized particles with distinct drying times is also observed. Smaller particles (<32 µm) leave the reactor via the gas outlet, while the majority of big particles leave it via the solids outlet, thus depicting in situ particle separation. The results revealed the feasibility and benefits of a multizone drying operation and that the RMD can be an attractive solution for spray drying technology.

scholarly journals Dodecyl Mercaptan Functionalized Copper Mesh for Water Repellence and Oil-water Separation

2021 ◽  
Vol 18 (4) ◽  
pp. 887-899
Author(s):  
Yanling Tian ◽  
Jiekai Feng ◽  
Zexin Cai ◽  
Jiaqi Chao ◽  
Dawei Zhang ◽  
...  
Keyword(s):  
Separation Efficiency ◽  
Synthesis Process ◽  
Water Separation ◽  
Oil Water Separation ◽  
One Step ◽  
Oil Water ◽  
Water Repellence ◽  
Copper Mesh ◽  
Dodecyl Mercaptan

AbstractReckless discharge of industrial wastewater and domestic sewage as well as frequent leakage of crude oil have caused serious environmental problems and posed severe threat to human survival. Various nature inspired superhy-drophobic surfaces have been successfully applied in oily water remediation. However, further improvements are still urgently needed for practical application in terms of facile synthesis process and long-term durability towards harsh environment. Herein, we propose a simple one-step dodecyl mercaptan functionalization method to fabricate Super-hydrophobic-Superoleophilic Copper Mesh (SSCM). The prepared SSCM possesses excellent water repellence and oil affinity, enabling it to successfully separate various oil-water mixtures with high separation efficiency (e.g., > 99% for hexadecane-water mixture). The SSCM retains high separating ability when hot water and strong corrosive aqueous solutions are used to simulate oil-water mixtures, indicating remarkable chemical durability of the dodecyl mercaptan functionalized copper mesh. Additionally, the efficiency can be well maintained during 50 cycles of separation, and the water repellence is even stable after storage in air for 120 days, demonstrating the reusability and long-term stability of the SSCM. Furthermore, the functionalized mesh also shows good mechanical robustness towards abrasion by sandpaper, and oil-water separation efficiency of > 96% can be obtained after 10 cycles of abrasion. The reported one-step dodecyl mercaptan functionalization could be a simple method for increasing the water repellence of copper mesh, and thereby be a great candidate for treating large-scale oily wastewater in harsh environments.

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