Removal of gas-side particulate fouling layers by foreign particles as a function of flow direction

Abd-Elhady, M.S.; Abdelhady, Salama; Rindt, Ccm Camilo; Steenhoven, Anton A. van

doi:10.1016/j.applthermaleng.2008.11.020

Cited by 21 publications

(5 citation statements)

References 34 publications

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“…The majority of the removal mechanisms, such as the impact of particles, turbulent bursts, round stress, and scrubbing action, are related to the fluid velocity. This relationship was experimentally demonstrated in previously published studies [36,37].…”

Section: Mean Valuessupporting

confidence: 53%

Experimental study of soot particle fouling on ribbed plates: Applicability of the critical local wall shear stress criterion

Paz

Suárez

Concheiro

et al. 2013

Experimental Thermal and Fluid Science

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This article examines the notion of critical wall shear stress as the key control parameter of the local fouling removal process. In this study, an experimental setup was developed for measuring fouling on enhanced surfaces. Specifically, the experimental configuration consists of a forced convection plate heat exchanger containing a one-pass rectangular channel with two ribbed plates arranged in a symmetrically staggered manner. The exhaust gases flow by the rib-roughened sides of the plates, and the flat sides can be cooled with water from the independent external coolant circuit.As a result of soot particle deposition from exhaust gases, a layer of fouling is deposited over the ribs.After asymptotic conditions were reached during the tests, detailed fouling thickness measurements were conducted. The dimensionless particle relaxation time during these tests was determined to be in the range of 0.3-10. The measurements were then complemented with a numerical analysis. In particular, the local wall shear stress was calculated using a commercial computational fluid dynamics (CFD) software package.The fouling thickness profiles deposited over the ribs and the local critical shear stress values were compared and discussed for two different geometries. The results obtained clearly support the idea that critical wall shear stress is an appropriate criterion for facilitating the understanding of the local behaviour of fouling deposits.

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Section: Mean Valuessupporting

confidence: 53%

Experimental study of soot particle fouling on ribbed plates: Applicability of the critical local wall shear stress criterion

Paz

Suárez

Concheiro

et al. 2013

Experimental Thermal and Fluid Science

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“…In the case of hydrophobic films, studies have suggested that super hydrophobic surfaces form microstructures and/or nanostructures that enhance the contact angle of water. So, when water droplets hit the surface, it would quickly roll off, carrying dust and other particles away 6 .…”

Section: Introductionmentioning

confidence: 99%

Improved Self-cleaning Properties of an Efficient and Easy to Scale up TiO2 Thin Films Prepared by Adsorptive Self-Assembly

Isaifan

Samara

Suwaileh

et al. 2017

Sci Rep

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Transparent titania coatings have self-cleaning and anti-reflection properties (AR) that are of great importance to minimize soiling effect on photovoltaic modules. In this work, TiO2 nanocolloids prepared by polyol reduction method were successfully used as coating thin films onto borosilicate glass substrates via adsorptive self-assembly process. The nanocolloids were characterized by transmission electron microscopy and x-ray diffraction. The average particle size was around 2.6 nm. The films which have an average thickness of 76.2 nm and refractive index of 1.51 showed distinctive anti soiling properties under desert environment. The film surface topography, uniformity, wettability, thickness and refractive index were characterized using x-ray diffraction, atomic force microscopy, scanning electron microscopy, water contact angle measurements and ellipsometry. The self-cleaning properties were investigated by optical microscopy and UV-Vis spectroscopy. The optical images show 56% reduction of dust deposition rate over the coated surfaces compared with bare glass substrates after 7 days of soiling. The transmission optical spectra of these films collected at normal incidence angle show high anti-reflection properties with the coated substrates having transmission loss of less than 6% compared to bare clean glass.

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“…It should finally be pointed out that the deposited carbon/soot particles on the tubes of the EGR cooler are so fragile that can be easily removed mechanically, i.e., by very simple brushing, or by strong air blasts (Abd-Elhady et al 2009). This is because the deposit is not subject to any consolidation by sintering (Ristic 1979) or hydrocarbons condensation, and therefore, removal of soot particle by the spiral insertion is a suitable online cleaning technique in EGR coolers.…”

Section: Resultsmentioning

confidence: 99%

Mitigation of Soot Deposition in Exhaust Gas Recirculation Coolers Using a Spiral Insert

Abd-Elhady

Malayeri

2013

Aerosol Science and Technology

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In diesel engines, the emission of nitrogen oxides can profoundly be controlled by using exhaust gas recirculation (EGR) coolers. Nevertheless, the deposition of unwanted materials, in form of primarily particulate matter and hydrocarbons, causes a major hurdle to the durability of such devices. In this study, a novel technique, i.e., a spiral insert, has been developed to mitigate particulate fouling in tubular EGR coolers. It is made of a helical rotating blade which is inserted inside the tubes of EGR coolers, and it rotates around its axis under the force of entering gas flow. As the blade rotates, it wipes out the deposit. An EGR experimental setup has also been used to examine how effective the spiral insert is in suppressing particulate fouling for two different gas velocities with and without using the insert. With no insert, the deposition was severe, fast, and continuous. For the latter, though, it was first very slow, and second, the fouling resistance was four times lower to that of no insert. No sign of any deposit was also observed on the insert after fouling runs. Despite the promising results, the insert requires further development so it can rotate at the low gas velocities.

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Removal of gas-side particulate fouling layers by foreign particles as a function of flow direction

Abstract: Removal of particulate fouling layers by externally injected particles as a function ACCEPTED MANUSCRIPTdownward flow is the best flow orientation to linger particulate fouling and for removal of fouling layers by externally injected particles.

Cited by 21 publications

References 34 publications

Experimental study of soot particle fouling on ribbed plates: Applicability of the critical local wall shear stress criterion

Experimental study of soot particle fouling on ribbed plates: Applicability of the critical local wall shear stress criterion

Improved Self-cleaning Properties of an Efficient and Easy to Scale up TiO2 Thin Films Prepared by Adsorptive Self-Assembly

Mitigation of Soot Deposition in Exhaust Gas Recirculation Coolers Using a Spiral Insert

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