Permeate Flux Curve Characteristics Analysis of Cross-Flow Vacuum Membrane Distillation

2011 ◽  
Vol 51 (1) ◽  
pp. 487-494 ◽  
Author(s):  
Hongtao Wang ◽  
Baoan Li ◽  
Li Wang ◽  
Shasha Song ◽  
Jixiao Wang ◽  
...  
Keyword(s):  
Cross Flow ◽  
Membrane Distillation ◽  
Permeate Flux ◽  
Characteristics Analysis ◽  
Vacuum Membrane Distillation ◽  
Flux Curve

Numerical Simulation of Cross-Flow Vacuum Membrane Distillation and Characteristics Analysis

2011 ◽  
Vol 396-398 ◽  
pp. 1846-1850
Author(s):  
Chang Li ◽  
Bao An Li ◽  
Shi Chang Wang
Keyword(s):  
Numerical Simulation ◽  
Cross Flow ◽  
Membrane Distillation ◽  
Inlet Temperature ◽  
Coefficient Distribution ◽  
Vacuum Degree ◽  
Membrane Flux ◽  
Characteristics Analysis ◽  
Vacuum Membrane Distillation ◽  
Feed Inlet

The mechanism of cross-flow vacuum membrane distillation (VMD) was discussed in this paper, and the coupled process of heat and mass transfer in numerical simulation was realized by writing user defined function (UDF). The numerical simulation results of membrane flux were well agree with experimental data. The membrane flux in various conditions of feed velocity, feed inlet temperature and vacuum degree was obtained in numerical simulation. Around the cross-section of a single hollow fiber, velocity distribution was approximately symmetrical; TPC and heat transfer coefficient distribution are consistent.

Characteristics analysis of cross flow vacuum membrane distillation process

2015 ◽  
Vol 488 ◽  
pp. 30-39 ◽  
Author(s):  
Linquan Sun ◽  
Li Wang ◽  
Ziyi Wang ◽  
Baoan Li ◽  
Shichang Wang
Keyword(s):  
Cross Flow ◽  
Membrane Distillation ◽  
Distillation Process ◽  
Characteristics Analysis ◽  
Vacuum Membrane Distillation

scholarly journals Performance Investigation of O-Ring Vacuum Membrane Distillation Module for Water Desalination

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Adnan Alhathal Alanezi ◽  
H. Abdallah ◽  
E. El-Zanati ◽  
Adnan Ahmad ◽  
Adel O. Sharif
Keyword(s):  
Flow Rate ◽  
Membrane Distillation ◽  
Membrane Module ◽  
Water Desalination ◽  
Feed Flow Rate ◽  
Permeate Flux ◽  
Vacuum Degree ◽  
Flat Sheet ◽  
Vacuum Membrane Distillation ◽  
Feed Temperature

A new O-ring flat sheet membrane module design was used to investigate the performance of Vacuum Membrane Distillation (VMD) for water desalination using two commercial polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF) flat sheet hydrophobic membranes. The design of the membrane module proved its applicability for achieving a high heat transfer coefficient of the order of 103 (W/m2 K) and a high Reynolds number (Re). VMD experiments were conducted to measure the heat and mass transfer coefficients within the membrane module. The effects of the process parameters, such as the feed temperature, feed flow rate, vacuum degree, and feed concentration, on the permeate flux have been investigated. The feed temperature, feed flow rate, and vacuum degree play an important role in enhancing the performance of the VMD process; therefore, optimizing all of these parameters is the best way to achieve a high permeate flux. The PTFE membrane showed better performance than the PVDF membrane in VMD desalination. The obtained water flux is relatively high compared to that reported in the literature, reaching 43.8 and 52.6 (kg/m2 h) for PVDF and PTFE, respectively. The salt rejection of NaCl was higher than 99% for both membranes.

A review on membrane applications and transport mechanisms in vacuum membrane distillation

2017 ◽  
Vol 34 (1) ◽  
Author(s):  
Rakesh Baghel ◽  
Sushant Upadhyaya ◽  
Kailash Singh ◽  
Satyendra P. Chaurasia ◽  
Akhilendra B. Gupta ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Membrane Separation ◽  
Critical Evaluation ◽  
Experimental Studies ◽  
Membrane Distillation ◽  
Permeate Flux ◽  
Separation Processes ◽  
Vacuum Membrane Distillation ◽  
Polarization Coefficient ◽  
The Impact

AbstractThe main aim of this article is to provide a state-of-the-art review of the experimental studies on vacuum membrane distillation (VMD) process. An introduction to the history of VMD is carried out along with the other membrane distillation configurations. Recent developments in process, characterization of membrane, module design, transport phenomena, and effect of operating parameters on permeate flux are discussed for VMD in detail. Several heat and mass transfer correlations obtained by various researchers for different VMD modules have been discussed. The impact of membrane fouling with its control in VMD is discussed in detail. In this paper, temperature polarization coefficient and concentration polarization coefficient are elaborated in detail. Integration of VMD with other membrane separation processes/industrial processes have been explained to improve the performance of the system and make it more energy efficient. A critical evaluation of the VMD literature is incorporated throughout this review.

Vacuum membrane distillation for seawater desalination: could it compete with reverse osmosis?

2003 ◽  
Vol 3 (5-6) ◽  
pp. 57-66 ◽  
Author(s):  
D. Wirth ◽  
C. Cabassud
Keyword(s):  
Energy Consumption ◽  
Reverse Osmosis ◽  
Membrane Distillation ◽  
Hollow Fibre ◽  
Permeate Flux ◽  
Seawater Desalination ◽  
Industrial Plants ◽  
Low Energy Consumption ◽  
In Series ◽  
Vacuum Membrane Distillation

This work addresses the potentialities of vacuum membrane distillation (VMD) using hollow fibre membranes for seawater desalination. Experiments were carried out with a synthetic salty water containing a concentration of NaCl from 0 up to 300 g/L. A Microza (Pall) hollow fibre module was used. Experimental results show that, for this module, concentration polarisation and heat transfer limitations are not significant and do not modify the permeate flux. This is a great advantage over reverse osmosis (RO). Energy consumption was then studied using computations based on modelling. Two different industrial plants were considered: the first one consisted of hollow fibre modules arranged in series and operated in a single-pass. The second one was designed for a discontinuous operation using a circulation loop. Computations clearly show the interest (low energy consumption) of VMD for seawater desalination in comparison with RO.

scholarly journals Investigation of Membrane Fouling in Vacuum Membrane Distillation (VMD) Using Blocking Filtration Laws

2022 ◽  
Vol 12 (1) ◽  
pp. 82
Author(s):  
Wajeeha Bibi ◽  
Muhammad Asif ◽  
Jawad Rabbi
Keyword(s):  
Membrane Fouling ◽  
Lower Energy ◽  
Constant Pressure ◽  
Membrane Distillation ◽  
Low Grade ◽  
Permeate Flux ◽  
Cake Layer ◽  
Vacuum Membrane Distillation ◽  
Critical Problems ◽  
Drinking Water Purification

VMD is one of the desalination technologies used for drinking water purification because of it higher permeate flux and lower energy consumption, and it uses low grade energy for operation. However, there are some critical problems related to VMD, one of which is membrane fouling. In the present study, the fouling phenomenon in VMD is investigated using constant pressure-blocking filtration laws. The results of constant pressure-blocking filtration law indicated that the permeate flux was initially unaffected by the cake layer, but with the passage of time as the pores began to constrict, a formation of a relatively thick cake layer was observed, which resulted in the decrease of permeate flux.

Sintering process investigation during polytetrafluoroethylene hollow fibre membrane fabrication by extrusion method

2017 ◽  
Vol 29 (9) ◽  
pp. 1069-1082 ◽  
Author(s):  
Jingxuan Jia ◽  
Guodong Kang ◽  
Tong Zou ◽  
Meng Li ◽  
Meiqing Zhou ◽  
...  
Keyword(s):  
Membrane Distillation ◽  
Hollow Fibre ◽  
Test Results ◽  
Sintering Process ◽  
Permeate Flux ◽  
Hollow Fibre Membrane ◽  
Membrane Fabrication ◽  
Fibre Membrane ◽  
Vacuum Membrane Distillation ◽  
Extrusion Method

In this study, the effect of sintering conditions including manner, temperature and duration on properties of polytetrafluoroethylene (PTFE) hollow fibre membrane fabricated by extrusion method was intensively investigated. Different from un-sintered and relaxed sintered, the fixed sintered PTFE hollow fibre membrane was observed to generate a uniform ‘fibril–node’ porous structure and a main crystal transformation to folded chain crystal with smaller size. Consequently, it was found that for fixed setting sintering, both temperature increase from 340°C to 400°C and duration prolongation obviously improved pore size, ethanol permeation performance and mechanical strength. Additionally, the test results revealed that the membrane sintered below virgin melting point (350°C) had a noticeable higher porosity but poorer ethanol permeation performance that could be primarily attributed to increased ratio of closed pore. The sintering condition exhibited evident influence on PTFE hollow fibre membrane thermal stability, though it showed no alteration to the thermal decomposition of PTFE. The obtained PTFE hollow fibre membrane was tested to evaluate their vacuum membrane distillation (VMD) performances. It was found that PTFE membrane from lower sintering temperature delivered a better salt rejection; on the other hand, the permeate flux was improved by increased vacuum pressure during VMD operation.

The Effect of PTFE Membrane Properties on Vacuum Membrane Distillation Module Performance

2018 ◽  
Author(s):  
Mustafa Usta ◽  
Robert M. Krysko ◽  
Ali E. Anqi ◽  
Ahmed M. Alshwairekh ◽  
Alparslan Oztekin
Keyword(s):  
Concentration Polarization ◽  
Membrane Distillation ◽  
Membrane Properties ◽  
Design Parameters ◽  
Membrane Thickness ◽  
Local Concentration ◽  
Permeate Flux ◽  
Flow Properties ◽  
Ptfe Membrane ◽  
Vacuum Membrane Distillation

This study investigates the effect of membrane properties — porosity, membrane thickness, and pore radius — on the performance of vacuum membrane distillation (VMD) process by achieving computational fluid dynamics (CFD) simulations on a three-dimensional domain of interest at fixed flow properties. The finite volume method (FVM) is adopted to solve momentum, solute mass transport, and energy equations in the feed channel. To accurately predict the rate of water vapor diffused through the membrane by Knudsen and viscous diffusion mechanism, local concentration, temperature, and flux are coupled at the membrane surfaces. In accordance with the flux, corresponding gradients for temperature and concentration are applied at the membrane boundaries. Since there is a strong coupling of flow properties at the membrane surface, the employed model is validated against an experimental study and further used to characterize the effect of PTFE membrane properties on permeate flux, temperature polarization, and concentration polarization. We found that different set of membrane design parameters substantially changes the total mass flux. The contribution of both viscous and Knudsen mechanism is comparable and, as such, prevents us neglecting neither of them. The temperature and concentration polarization are even more undesirable level for the larger pore sizes.

scholarly journals Energy evaluation and treatment efficiency of vacuum membrane distillation for brackish water desalination

2014 ◽  
Vol 5 (2) ◽  
pp. 119-131
Author(s):  
Mohammad Ramezanianpour ◽  
Muttucumaru Sivakumar
Keyword(s):  
Brackish Water ◽  
Potable Water ◽  
Membrane Separation ◽  
Rapid Development ◽  
Membrane Distillation ◽  
Water Desalination ◽  
Treated Wastewater ◽  
Permeate Flux ◽  
Effective Parameters ◽  
Vacuum Membrane Distillation

Strict environmental regulations have led to the rapid development of membrane separation technologies for the production of potable water, for industrial water supply, and for the reuse and discharge of treated wastewater. Promotion of water recycling and the provision of potable water from brackish water prevent significant negative effects on the environment and drinking water supplies. This study is intended to describe and compare a sustainable technology for brackish water treatment. Among the four configurations of the membrane distillation process, vacuum membrane distillation (VMD) produces higher flux and results in a low fouling rate. It comprises evaporation and condensation that mimics what occurs in nature. Mathematical models proposed for the VMD transport mechanisms are incorporated to predict the actual experimental flux. The response of the flux rate to various process operating parameters is demonstrated. Variation of effective parameters is investigated in terms of energy consumption. The data indicate that the permeate flux is highly responsive to the variation of pressure and temperature. VMD enables the removal of 99.9% of total dissolved solids from natural and contaminated water sources. The findings are that the quality of the permeate water from all sources was at acceptable standards for potable use.

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