A New Approach to Evaluate and Optimize Swirl Tube Demister Efficiency

Author(s):  
Kyle Anderson ◽  
Ben Reinhardt ◽  
Walead Sultani ◽  
Hannah O' Hern ◽  
Xiang Zhang ◽  
...  

Abstract The focus of this report is on a new technique to quantify the air-water separation efficiency of a swirl tube demister that has application in numerous water purification systems. This experimental study adds to the existing literature by quantifying the effect of design parameters on both the previously studied water collection efficiency, as well as the air bypass efficiency, defined as the ratio of the air mass flowrate exiting at the desired air outlet, over the inlet air mass flowrate. This parameter is important for the water purification field because air acts as a carrier of contaminants, necessitating that it does not leak into the purified water collection chamber. Results from this study showed there was a clear trend when comparing the air bypass efficiency to the inlet air to water ratio. As the inlet air to water ratio increased, the air bypass efficiency decreased. This trend was consistent among four different experimental apparatuses indicating that either the geometry of the swirl tube had very little effect of the air bypass efficiency, or that the ranges tested for dimensions thought to affect the swirl tube performance were not varied enough.

Author(s):  
Kyle Anderson ◽  
Xiang Zhang ◽  
Bahman Abbasi

Abstract This paper provides a detailed design guide, optimization, and performance assessment for air-water separation of an axial flow cyclone. Axial flow cyclones (also known as swirl tube demisters, mist eliminators, or Austin-Write cyclones) have a range of applications in several different industries. This method of gas-liquid separation offers many benefits. Among these are high separation efficiency in high pressure applications (over 90% at 1 MPa) and an inline design that allows them to be more easily fitted into existing piping structures. Despite these benefits, there is a lack of recent literature on their design criteria and performance optimization. This research fills the gap in the literature by quantifying the effect of design parameters on water collection efficiency, ?_(water collection), and the air bypass efficiency, ?_(air bypass), defined as the ratio of the air mass flowrate exiting through the desired air outlet over the inlet air mass flowrate. A set of wide-ranging experiments were conducted to study the effects of gas-liquid flow rates, tube geometry, and relative injection angles to optimize water collection and air bypass efficiencies. The water collection efficiency exceeded 99.8% when the liquid streamline came in direct contact with the water drainage exit. An empirical correlation was developed to predict the swirl pitch as a function of the above design parameters. Predictions from the correlation were within 10% of the experimental results. The correlation can be used to design highly efficient in-line gas-liquid separators.


RSC Advances ◽  
2016 ◽  
Vol 6 (105) ◽  
pp. 103632-103640 ◽  
Author(s):  
Arun K. Singh ◽  
Jayant K. Singh

Fluorine free superhydrophobic coating on cotton fabric by inexpensive dip coating method. The coated fabric exhibited high oil–water separation efficiency.


2021 ◽  
Vol 18 (3) ◽  
pp. 501-533
Author(s):  
Kui Wan ◽  
Xuelian Gou ◽  
Zhiguang Guo

AbstractWith the explosive growth of the world’s population and the rapid increase in industrial water consumption, the world’s water supply has fallen into crisis. The shortage of fresh water resources has become a global problem, especially in arid regions. In nature, many organisms can collect water from foggy water under harsh conditions, which provides us with inspiration for the development of new functional fog harvesting materials. A large number of bionic special wettable synthetic surfaces are synthesized for water mist collection. In this review, we introduce some water collection phenomena in nature, outline the basic theories of biological water harvesting, and summarize six mechanisms of biological water collection: increased surface wettability, increased water transmission area, long-distance water delivery, water accumulation and storage, condensation promotion, and gravity-driven. Then, the water collection mechanisms of three typical organisms and their synthesis are discussed. And their function, water collection efficiency, new developments in their biomimetic materials are narrated, which are cactus, spider and desert beetles. The study of multiple bionics was inspired by the discovery of Nepenthes’ moist and smooth peristome. The excellent characteristics of a variety of biological water collection structures, combined with each other, are far superior to other single synthetic surfaces. Furthermore, the main problems in the preparation and application of biomimetic fog harvesting materials and the future development trend of materials fog harvesting are prospected.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Farideh Haghighi ◽  
Zahra Talebpour ◽  
Amir Sanati-Nezhad

AbstractFlow distributor located at the beginning of the micromachined pillar array column (PAC) has significant roles in uniform distribution of flow through separation channels and thus separation efficiency. Chip manufacturing artifacts, contaminated solvents, and complex matrix of samples may contribute to clogging of the microfabricated channels, affect the distribution of the sample, and alter the performance of both natural and engineered systems. An even fluid distribution must be achieved cross-sectionally through careful design of flow distributors and minimizing the sensitivity to clogging in order to reach satisfactory separation efficiency. Given the difficulty to investigate experimentally a high number of clogging conditions and geometries, this work exploits a computational fluid dynamic model to investigate the effect of various design parameters on the performance of flow distributors in equally spreading the flow along the separation channels in the presence of different degrees of clogging. An array of radially elongated hexagonal pillars was selected for the separation channel (column). The design parameters include channel width, distributor width, aspect ratio of the pillars, and number of contact zone rows. The performance of known flow distributors, including bifurcating (BF), radially interconnected (RI), and recently introduced mixed-mode (MMI) in addition to two new distributors designed in this work (MMII and MMIII) were investigated in terms of mean elution time, volumetric variance, asymmetry factors, and pressure drop between the inlet and the monitor line for each design. The results show that except for pressure drop, the channel width and aspect ratio of the pillars has no significant influence on flow distribution pattern in non-clogged distributors. However, the behavior of flow distributors in response to clogging was found to be dependent on width of the channels. Also increasing the distributor width and number of contact zone rows after the first splitting stage showed no improvement in the ability to alleviate the clogging. MMI distributor with the channel width of 3 µm, aspect ratio of the pillars equal to 20, number of exits of 8, and number of contact zones of 3 exhibited the highest stability and minimum sensitivity to different degrees of clogging.


2021 ◽  
Vol 18 (4) ◽  
pp. 887-899
Author(s):  
Yanling Tian ◽  
Jiekai Feng ◽  
Zexin Cai ◽  
Jiaqi Chao ◽  
Dawei Zhang ◽  
...  

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.


Author(s):  
Noman Yousuf ◽  
Timothy Anderson ◽  
Roy Nates

Abstract Despite being identified nearly a century ago, the diffusion absorption refrigeration (DAR) cycle has received relatively little attention. One of the strongest attractions of the DAR cycle lies in the fact that it is thermally driven and does not require high value work. This makes it a prime candidate for harnessing low grade heat from solar collectors, or the waste heat from stationary generators, to produce cooling. However, to realize the benefits of the DAR cycle, there is a need to develop an improved understanding of how design parameters influence its performance. In this vein, this work developed a new parametric model that can be used to examine the performance of the DAR cycle for a range of operating conditions. The results showed that the cycle's performance was particularly sensitive to several factors: the rate of heat added and the temperature of the generator, the effectiveness of the gas and solution heat exchangers, the mass flowrate of the refrigerant and the type of the working fluid. It was shown that can deliver good performance at low generator temperatures if the refrigerant mass fraction in the strong solution is made as high as possible. Moreover, it was shown that a H2O-LiBr working pair could be useful for achieving cooling at low generator temperatures.


2021 ◽  
Author(s):  
Steinar Asdahl ◽  
Johann Jansen van Rensburg ◽  
Martin Einarson Waag ◽  
Rune Glenna Nilssen

Abstract Traditionally, produced water from production separators is handled by multiple steps and different technologies in order to meet the required quality for either discharge or reinjection of the water. The development of the latest Compact Flotation Unit (CFU) technology has unlocked the potential for savings on cost, complexity, footprint and weight for the produced water treatment system. The developed CFU technology has proven applicable through field testing as a single treatment technology for reducing Oil-in-Water (OiW) content directly from tie-in at separator and still meet stringent requirements for outlet OiW quality. Field tests were conducted with inlet OiW concentration ranging from 200-2000 ppm, achieving results in the range 2.5 to 21 ppm only with a two-stage latest generation CFU. Compared to a traditional produced water system setup consisting of de-oiling hydrocyclones and a horizontal degassing vessel, the savings in footprint and operational weight is estimated to 54 % and 53 % respectively utilizing a two-stage CFU for a system with a design capacity of 76.000 BWPD. Furthermore, the development of the latest generation CFU technology has enabled the retrofit concept, incorporating the developed CFU internals into existing gravity separation based produced water vessels, converting them to more efficient flotation vessels with increased capacity. For brownfield and debottlenecking applications, operators are challenged by increasing water cut from maturing wells, and as a result exceeding the facilities design capacity for produced water treatment. This challenge is often further reinforced by increasingly stricter environmental legislation for OiW content for discharge or re-injection. The retrofit concept will offer a highly cost-, footprint- and weight-efficient solutions to these challenges utilizing existing vessels. Benefits of the retrofit concept: Bring proven and unique performance of the technology to other produced water separation vessels helping the operators improve the separation efficiency and increase throughput while meeting discharge requirementsShort execution time compared to installation of new process equipmentLow cost compared to installation of new process equipmentUtilization of existing equipment saves valuable footprint.


Open Physics ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 486-493
Author(s):  
Ting Liang ◽  
Biao Wang ◽  
Zhenzhong Fan ◽  
Qingwang Liu

Abstract A facile method for fabricating superhydrophobic and superoleophilic powder with 5A zeolite and stearic acid (SA) is reported in this study. The effect of different contents of SA on contact angle (CA) was investigated. The maximum water CA was 156.2°, corresponding to the optimum SA content of 1.5 wt%. The effects of SA and the mechanism of modified 5A zeolite powder by SA were analyzed by sedimentation analysis experiment, FTIR analysis, particle size analysis, and SEM characterization. The SA-modified 5A zeolite was used as an oil sorbent to separate oil–water mixture with potential use in floating oil. The separation efficiency was above 98%.


Sign in / Sign up

Export Citation Format

Share Document