scholarly journals Testing of 3D Printed Turbulence Promoters for Membrane Filtration

2020 ◽  
Vol 64 (3) ◽  
pp. 371-376
Author(s):  
Igor Gáspár ◽  
Réka Neczpál
Keyword(s):  
Pressure Drop ◽  
3D Printing ◽  
Membrane Filtration ◽  
Permeate Flux ◽  
Water Emulsion ◽  
Static Mixers ◽  
Oil In Water ◽  
Negative Effect ◽  
3D Printed ◽  
Oil In Water Emulsion

Membrane filtration process can be intensified by using static mixers inside tubular membranes. Most of commercial static mixers are optimized for mixing fluids, not for membrane filtration. We have developed new turbulence promoter geometries designed for intensification of permeate flux and retention without significant pressure drop along the membrane. In previous experiments, we used metallic turbulence promoters, but in this work, FDM 3D printing technology was used to create these improved geometries, which are new in membrane filtration and they have the same geometry as existing metallic versions. New 3D printed objects were tested with filtration of stable oil-in-water emulsion. Our experiments proved that 3D printed static mixers might be as effective as metallic versions. The effect on initial flux and retention of oil was very similar. Pressure drop along membrane was slightly higher (but significantly lower from pressure drop along the membrane resulted by commercial static mixers, designed only for mixing fluids). Higher pressure drop may be the result of rougher surface due the layer-technology of 3D printing. This negative effect can be reduced by using a smaller nozzle (which will produce smaller layers) or smoothing the surface. PLA is material easier for printing, but from these two materials, PETG is a better choice due its higher operating temperature and better water-resist properties too.

scholarly journals Fouling Mitigation in Tubular Membranes by 3D-printed Twisted Tape Turbulence Promoters

2019 ◽  
Author(s):  
Matthias Wessling
Keyword(s):  
Energy Consumption ◽  
Membrane Filtration ◽  
Specific Energy Consumption ◽  
Twisted Tape ◽  
Static Mixer ◽  
Permeate Flux ◽  
Severe Problem ◽  
Static Mixers ◽  
3D Printed ◽  
Tubular Membranes

Despite intensive research, fouling remains a severe problem in membrane filtration. It is often controlled by applying turbulent flow which requires a higher energy consumption. So-called turbulence promoters or static mixers can be inserted into the flow channel of tubular membranes. They deflect the fluid, induce vortices, enhance particle back-transport and increase the shear rate at the membrane surface, thus mitigating fouling. However, little is known how the geometry of such turbulence promotors affects the reduction of fouling. We investigate how different 3D-printed mixer geometries affect fouling and improve the flux during filtration with humic acid. Most mixer geometries used in the present study are based on a twisted tape; a Kenics static mixer is investigated as well. Static mixers with changing diameter prove to be less effective than twisted tape mixers with constant diameter which lead to an increase in permeate flux of around 130%. The highest flux improvement of 140% can be reached by applying a Kenics mixer. Regardless of their geometry, all investigated static mixer cause higher permeate fluxes at same specific energy consumption. Again, the Kenics mixer proves to be the most efficient static mixer. The presented mixer geometries can be fabricated with undercut injection molding techniques and represent a simple and viable option to make tubular membrane based filtration processes more efficient.

scholarly journals Membrane surface properties and their effects on real waste oil-in-water emulsion ultrafiltration

Water SA ◽  
2019 ◽  
Vol 45 (3 July) ◽  
Author(s):  
Marjana Simonič
Keyword(s):  
Surface Properties ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Cross Flow ◽  
Influential Factors ◽  
Permeate Flux ◽  
Chemical Cleaning ◽  
Water Emulsion ◽  
Oil In Water ◽  
Oil In Water Emulsion

Membrane surface properties and their effect on the efficiency of ultrafiltration (UF) of real waste oily emulsions was studied. Experiments were performed in cross-flow operation at total recycle condition in a lab-scale system. The ceramic UF membrane in the tubular type module was employed. During the experiments permeate flux was measured. The most important influential factors, such as temperature, TMP, and pH, were considered during the experiments. Zeta potential was measured in order to explain the phenomena on the membrane surface. The isoelectric point of the fouled membrane was shifted to the alkaline range. COD removal efficiency reached 89%. Gas chromatography measurements were performed in order to determine the composition of waste emulsions. SEM micrographs showed the formation of calcite on the membrane, which contributed to membrane fouling. Chemical cleaning was examined using alkaline and acid solutions, and a cleaning strategy was determined.

scholarly journals INVERSION POINT OF EMULSIONS AS A MECHANISM OF HEAD LOSS REDUCTION IN ONSHORE PIPELINE HEAVY OIL FLOW

2021 ◽  
Vol 15 (1-2) ◽  
pp. 13-24
Author(s):  
M. R. Justiniano ◽  
O. J. Romero
Keyword(s):  
Heat Exchange ◽  
Pressure Drop ◽  
High Heat ◽  
Oil Viscosity ◽  
Inversion Point ◽  
Water Emulsion ◽  
Oil Emulsion ◽  
Oil In Water ◽  
Water Cut ◽  
Oil In Water Emulsion

This work addresses the transportation of viscous crude oil as concentrated oil-in-water (O/W) emulsions flowing in a partially submerged onshore pipeline. The main goal of this study is to analyze the effects of inversion point of the water-in-oil emulsion in the pressure drop with the aid of Pipesim® software. Pressure drop is determined by applying the Dukler correlation (Taitel and Dukler, 1976) to represent dead oil viscosity as a function of temperature, and API density using the Hossain correlation (Hossain et al., 2005). The Brinkman model (Brinkman, 1952) is applied to calculate the viscosity of the emulsion, with the Brauner and Ullmann (2002) equation for the water cut off method (inversion point). The pipeline, of 3,600 m and 4 inches in diameter, transports the oil and consists of three sections. The first and third sections are above ground and are in contact with the external environment. The intermediate section is sitting on the river bed and is the critical part of the pipeline, once high heat losses are observed. The results of this 1D and non-isothermal problem show that water cuts of 5 and 6%, for low heat exchange and high heat exchange, respectively, make it possible to transport the oil, as an oil-in-water emulsion, through the entire extension of the pipeline. However, a water cut of 10% creates a high-pressure drop in the system, assuring the movement of the fluid in long sections without compromising the system operation. The use of isolation influences the temperature gradient but doesn’t have a high influence on pressure gradient compared to emulsions.

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