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.

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 Fabrication and characterization of composite hollow fibre membrane derived from hydroxyapatite cow bone and kaolin

2021 ◽  
Vol 1142 (1) ◽  
pp. 012011
Author(s):  
Suraya Najieha Kamarudin ◽  
Mohd Riduan Jamalludin ◽  
Siti Nor Suhaida Rasman ◽  
Siti Khadijah Hubadillah ◽  
Mohd Arif Budiman Pauzan ◽  
...  
Keyword(s):  
Hollow Fibre ◽  
Hollow Fibre Membrane ◽  
Fibre Membrane ◽  
Fabrication And Characterization ◽  
Cow Bone

Blood compatibility of two different types of membrane oxygenator during cardiopulmonary bypass in infants

1994 ◽  
Vol 17 (10) ◽  
pp. 543-548 ◽  
Author(s):  
Y.J. Gu ◽  
P.W. Boonstra ◽  
C. Akkerman ◽  
H. Mungroop ◽  
I. Tigchelaar ◽  
...  
Keyword(s):  
Cardiopulmonary Bypass ◽  
Blood Compatibility ◽  
Hollow Fibre ◽  
Membrane Oxygenator ◽  
Hollow Fibre Membrane ◽  
Flat Sheet ◽  
Fibre Membrane ◽  
Membrane Oxygenators ◽  
Flat Sheet Membrane ◽  
Sheet Membrane

The contact of blood with the artificial extracorporeal circuit causes a systemic inflammatory response due to blood activation. In this study, we compared two different paediatric membrane oxygenators used for extracorporeal circulation: a hollow fibre membrane oxygenator (Dideco Masterflo D-701, n=10), and a flat sheet silicone membrane oxygenator (Avecor Kolobow 800-2A, n=10). Blood compatibility was indicated by measuring complement activation as well as leukocyte and platelet activation. In patients perfused with a flat sheet membrane oxygenator, concentrations of complement split products C3a were significantly increased 30 minutes after the start of bypass (p<0.01), whereas only a mild increase of C3a was found in patients perfused with a hollow fibre membrane oxygenator. Leukocyte and platelet counts dropped uniformly in both groups after the start of bypass mainly due to hemodilution. Activation of leukocytes and platelets identified by both plasma β-glucuronidase and β-thromboglobulin was similar in both groups. Infants perfused with a flat sheet membrane oxygenator received significantly more donor blood than those perfused with a hollow fibre oxygenator (p<0.05). These results indicate that when used during paediatric cardiopulmonary bypass, a flat sheet membrane oxygenator has a higher complement activity than a hollow fibre membrane oxygenator, which is probably due to the relatively larger blood-surface contacting area of the oxygenator.

Recovery of Sulfur Dioxide Using Non-Dispersive Absorption

2007 ◽  
Vol 5 (1) ◽  
Author(s):  
Patricia Luis ◽  
Inmaculada Ortiz ◽  
Rubén Aldaco ◽  
Aurora Garea ◽  
Ángel Irabien
Keyword(s):  
Gas Phase ◽  
Plug Flow ◽  
Hollow Fibre ◽  
Absorption Efficiency ◽  
Environmental Risks ◽  
Process Efficiency ◽  
Selective Absorption ◽  
Hollow Fibre Membrane ◽  
Fibre Membrane ◽  
Removal Of So2

Removal of SO2 from gas emissions by selective absorption into a liquid is a common method to reduce air pollution and environmental risks. The absorption efficiency is determined by the interaction between the gases and the liquid. A great number of gas desulphurization methods have been developed where aqueous or organic solvents are used as sorbents.N,N-dimethylaniline (DMA) is an organic solvent used in the industry because its affinity with SO2. This absorption is neither too strong nor too weak, thus absorption and desorption can occur leading to a regenerative process where SO2 can be recovered. However, a direct contact between SO2 and DMA leads to several environmental problems caused by solvent evaporation and drops dragging into the gas stream.In order to increase the process efficiency and reduce environmental risks, a non-dispersive absorption process using hollow fibre membrane modules is developed in this work for a solvent zero emission process. The mass transfer into a fibre may be described by three main assumptions: gas-phase laminar flow, gas-phase plug-flow and gas-phase mixing. A numerical calculation was carried out to establish the performance of a hollow fibre membrane contactor for the removal of SO2 when water and N,N-dimethylaniline are used as sorbents in order to compare both, wetted and non-wetted operating modes.

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