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Articles 2851 - 2880 of 3572

Full-Text Articles in Operations Research, Systems Engineering and Industrial Engineering

Influence Of Different Surface Materials On Nucleation And Crystal Growth In Heat Exchangers, T. Geddert, S. Kipp, W. Augustin, S. Scholl Jul 2007

Influence Of Different Surface Materials On Nucleation And Crystal Growth In Heat Exchangers, T. Geddert, S. Kipp, W. Augustin, S. Scholl

Heat Exchanger Fouling and Cleaning VII

The influence of different materials on the fouling tendency in saline calcium sulfate solution was investigated. The effects of the untreated material on the crystallization process have been studied experimentally in the micro- and macroscopic scale. The crystallization in the induction period was visualized with SEM and AFM to locate preferred nucleation spots and to visualize the crystal growth. The different materials are showing different crystal growth behavior (number and size of the crystals). These results are corresponding with the macroscopic fouling results with limited shear stress. Also different roughness values on stainless steel have been studied with respect to …

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Fouling In A Centritherm Evaporator With Whey Solutions, R. S. Jebson, H. Chen, O. H. Campanella Jul 2007

Fouling In A Centritherm Evaporator With Whey Solutions, R. S. Jebson, H. Chen, O. H. Campanella

Heat Exchanger Fouling and Cleaning VII

Fouling caused by sweet cheese whey and reconstituted whey powder solutions was studied in a Centritherm evaporator, the behaviour being estimated by measuring the change in the overall heat transfer coefficients with the time. It was found that there was no fouling detectable for the reconstituted whey powder solution. For sweet cheese whey, the fouling rate was linked strongly with the evaporating temperature and temperature difference. Visual observation showed that the deposit layer on the evaporator surface was very thin and soft, and like the type A milk deposit described by other investigators. A high velocity of liquid film delayed …

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Simulation Of Calcium Phosphate Deposition On Stainless Steel Surfaces: A New Approach Based On Cellular Automata, F. G. Martins, T. Campos, R. Rosmaninho, L. F. Melo Jul 2007

Simulation Of Calcium Phosphate Deposition On Stainless Steel Surfaces: A New Approach Based On Cellular Automata, F. G. Martins, T. Campos, R. Rosmaninho, L. F. Melo

Heat Exchanger Fouling and Cleaning VII

Fouling caused by calcium phosphate upon heating is basically a crystallization/precipitation process, which starts with the formation of stable clusters of ions or molecules in a process called nucleation that occurs either in the bulk liquid or at the surface. The cellular automata are useful tools to model complex systems of the universe. They could be considered as a good alternative to differential equations and have been used to model many physical/biological systems. In this preliminary work, a two dimensional space was considered where the cellular automata lattice was represented as a grid of squares, with each square representing a …

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Experimental Investigation Of Crystallization Fouling On Grooved Stainless Steel Surfaces During Convective Heat Transfer, A. Al-Janabi, M.R. Malayeri, H. Müller-Steinhagen Jul 2007

Experimental Investigation Of Crystallization Fouling On Grooved Stainless Steel Surfaces During Convective Heat Transfer, A. Al-Janabi, M.R. Malayeri, H. Müller-Steinhagen

Heat Exchanger Fouling and Cleaning VII

The beneficial aspects of enhanced or extended heat transfer surfaces may be off-set if operated under fouling conditions. In the present paper, preliminary experimental results for crystallization fouling of CaSO4 solutions onto surfaces with different structures are reported. Flat stainless steel plates (50 mm x 59 mm) with 'V' shaped grooves on the side of fluid flow were used as heat transfer surfaces. Experiments were carried out both under clean and fouling conditions to discern how the same surface structures perform under such circumstances. In addition, the impact of both, the direction of grooves with respect to fluid flow (crossed, …

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A Real Time Monitoring Model Of The Calcium Carbonate Fouling Induction Period Based On The Conductance Titration, S.R. Yang, S.X. Cao, L.J. Chen, Z.M. Xu, M.L. Yu, W.H. Sun, K.L. Zheng Jul 2007

A Real Time Monitoring Model Of The Calcium Carbonate Fouling Induction Period Based On The Conductance Titration, S.R. Yang, S.X. Cao, L.J. Chen, Z.M. Xu, M.L. Yu, W.H. Sun, K.L. Zheng

Heat Exchanger Fouling and Cleaning VII

A new method has been developed to monitor the calcium carbonate fouling induction period (CCFIP) in real time. Based on the conductance titration, this paper investigated the forming process of CCFIP by a staticdynamic combined simulation experiment unit. With the help of titration analysis (that is titrimetry), an accurate definition of CCFIP and the corresponding real time monitoring model were built up. The investigation results show that the proposed model applies not only to measure the CCFIP in real time, but also applies to an investigation of the influence of various factors on the CCFIP.

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Fouling Mitigation With Synthetic Fibres In A Caso4 Supersaturated Solution, M. Rost, G. G. Duffy Jul 2007

Fouling Mitigation With Synthetic Fibres In A Caso4 Supersaturated Solution, M. Rost, G. G. Duffy

Heat Exchanger Fouling and Cleaning VII

Wood pulp fibre suspensions and model synthetic fibre suspensions have been shown previously to mitigate effectively calcium sulphate fouling in heat exchangers. Fibre flexibility was found to be a decisive fibre property in fouling mitigation. Adding fibres to a fouling fluid is environmentally benign and can be applied during operation without shutting down the heat exchanger. Because polymer fibres are more robust in a hostile environment, further work was initiated with two types of rayon fibre and one acrylic fibre of the same fibre length. Experiments were performed at both constant and varying fibre volume concentrations. The more flexible rayon …

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Extending The Induction Period Of Crystallization Fouling Through Surface Coating, T. Geddert, I. Bialuch, W. Augustin, S. Scholl Jul 2007

Extending The Induction Period Of Crystallization Fouling Through Surface Coating, T. Geddert, I. Bialuch, W. Augustin, S. Scholl

Heat Exchanger Fouling and Cleaning VII

To minimize the negative effects of scale formation in heat exchangers, new anti-fouling strategies are focusing on the modification of heat transfer surfaces. These modifications should lead to tailored made surfaces for different technical applications. Aim of this surface modification is the extension of the induction period to minimize the negative effects of fouling and maximize the endurance of the heat exchanger. To achieve such, different surface coatings on stainless steel were investigated in respect of fouling tendency. The effect of flow velocity respectively Reynolds number on the induction time of CaSO4 crystallization fouling were tested in different test units. …

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Interaction Of Whey Protein With Modified Stainless Steel Surfaces, S.S. Premathilaka, M.M. Hyland, X.D. Chen, L.R. Watkins, B. Bansal Jul 2007

Interaction Of Whey Protein With Modified Stainless Steel Surfaces, S.S. Premathilaka, M.M. Hyland, X.D. Chen, L.R. Watkins, B. Bansal

Heat Exchanger Fouling and Cleaning VII

Modified stainless steel surfaces were fouled with whey protein solutions to study the deposition mechanisms and the effects of surface modification. Stainless steel samples were coated with diamond-like carbon (DLC) and titanium nitride (TiN). These surfaces are expected to present different surface chemistries to stainless steel in terms of their functional groups and hydrophobic or hydrophilic nature. Thus, it is expected that foulant-surface interactions will differ for the various fouled surfaces. The substrates were exposed to a flowing whey protein solution in a fouling rig designed to achieve laminar flow. X-ray Photoelectron Spectroscopy (XPS) was used to study the initial …

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Surface Treatment For The Mitigation Of Whey Protein Fouling, W. Augustin, T. Geddert, S. Scholl Jul 2007

Surface Treatment For The Mitigation Of Whey Protein Fouling, W. Augustin, T. Geddert, S. Scholl

Heat Exchanger Fouling and Cleaning VII

Heat transfer fouling experiments were carried out in a temperature controlled stirred vessel using aqueous solutions of whey protein concentrate in the concentration range of 3 to 3.5 wt-% at a bulk temperature of 50 °C and pH of 6. Heat transfer data were obtained from thermocouples embedded in an immersed electrical heating rod with various metal plates attached with-and-without surface treatments. Measurements included solution temperature, heating element surface temperature, and heat duty. Results are presented as fouling resistance versus time for aluminum, copper, stainless steel, electro-polished stainless steel, and surfaces coated with DLC and doped with Si , SiO, …

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Experiments And Modelling Of Calcium Sulphate Precipitation Under Sensible Heating Conditions: Initial Fouling And Bulk Precipitation Rate Studies, F. Fahiminia, A. P. Watkinson, N. Epstein Jul 2007

Experiments And Modelling Of Calcium Sulphate Precipitation Under Sensible Heating Conditions: Initial Fouling And Bulk Precipitation Rate Studies, F. Fahiminia, A. P. Watkinson, N. Epstein

Heat Exchanger Fouling and Cleaning VII

Crystallization of calcium sulphate, an inverse solubility salt, on a heated surface under sensible heating conditions has been studied. A temperature measurement technique was employed to detect initial fouling rates. Fouling experiments were carried out to determine how process variables such as surface temperature and velocity affect the initial fouling rates of calcium sulphate scaling. Experimental results show that, at a given surface temperature, there exists a maximum initial fouling rate for a range of fluid velocities. Also, this maximum rate and the fluid velocity at which it occurs both increase as the surface temperature increases. These observations are all …

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Flow Cell Studies On Fouling Caused By Protein -Calcium Phosphate Deposition In Turbulent Flow, R. Rosmaninho, G. Rizzo, H. Muller-Steinhagen, L. F. Melo Jul 2007

Flow Cell Studies On Fouling Caused By Protein -Calcium Phosphate Deposition In Turbulent Flow, R. Rosmaninho, G. Rizzo, H. Muller-Steinhagen, L. F. Melo

Heat Exchanger Fouling and Cleaning VII

A comparative study of the calcium phosphate fouling process, with and without proteins, was carried out using both standard 316 2R stainless steel and 2R surfaces modified by TiN magnetron sputtering. Fouling behavior was assessed in a heat transfer flow cell operating in the turbulent flow regime. The fouling curves resulting from calcium phosphate deposition in the absence of proteins were substantially different from the ones obtained when protein was present. In this last case, two different fouling periods could be observed. The surface energy of the modified materials was found to affect the deposition parameters (rate of deposition and …

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Investigation Of Fouling Process For Convective Heat Transfer In An Annular Duct, Y.C. Chen, Z.H. Quan, C.F. Ma Jul 2007

Investigation Of Fouling Process For Convective Heat Transfer In An Annular Duct, Y.C. Chen, Z.H. Quan, C.F. Ma

Heat Exchanger Fouling and Cleaning VII

Experimental and theoretical study is summarized of fouling process on heat transfer surface. An automatic monitoring system was set up to determine impact of fouling. Experiments were performed with artificial hard water as a working fluid at different conditions. Some important parameters including water temperature, wall temperature, flow velocity, water hardness and alkalinity were testified to make sure their influences on the fouling process on heat transfer surfaces. The ranges of water temperature, wall temperature, flow velocity and water hardness are between 20～50℃, 50～75℃, 0.5～2.0m/s, 200 ～ 1000mg/L (as CaCO3), respectively. All the experimental data were recorded continuously and the …

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Fouling Mechanisms By Ab Initio Calculations Condensation Reactions On The Rutile (101) Surface And Adsorption Of Ions On The Cr2o3 Surfaces, E. Puhakka, M. Riihimäki, R.L. Keiski Jul 2007

Fouling Mechanisms By Ab Initio Calculations Condensation Reactions On The Rutile (101) Surface And Adsorption Of Ions On The Cr2o3 Surfaces, E. Puhakka, M. Riihimäki, R.L. Keiski

Heat Exchanger Fouling and Cleaning VII

Molecular modelling approach was utilized to describe detailed fouling mechanism caused by crystallization. The interest was on the heat transfer surfaces, which were manufactured from titanium and stainless steel. With ab initio calculations, the role of the surface oxide layer structure of titanium and stainless steel on fouling was investigated. The surface structure of titanium and stainless steel were assumed to consist of rutile (TiO2) and dichromium trioxide (Cr2O3), respectively. It was found that the inorganic fouling depends strongly on the oxide layer structure and the existence of hydroxyl groups on the surface. Based on the results, two mechanistically different …

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Modelling Of Particulate Fouling On Heat Exchanger Surfaces: Influence Of Bubbles On Iron Oxide Deposition., D.H. Lister, F.C. Cussac Jul 2007

Modelling Of Particulate Fouling On Heat Exchanger Surfaces: Influence Of Bubbles On Iron Oxide Deposition., D.H. Lister, F.C. Cussac

Heat Exchanger Fouling and Cleaning VII

Studies of iron oxide deposition on Alloy-800 heatexchanger tubes have been part of a continuing research program at the University of New Brunswick; the present work formulates mechanisms for the effect of bubbles on deposition in water under boiling conditions. To supplement results from earlier deposition experiments in a fouling loop at UNB, measurements of bubble frequency and departure diameter as a function of heat flux were performed. High-speed movies of bubbling air/water systems indicated that a pumping action moved particles from adjacent areas at the surface to bubble nucleation sites. To explain the observations, the model considers deposition and …

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Simultaneous Consideration Of Flow And Thermal Effects Of Fouling In Crude Oil Preheat Trains, G.T. Polley, A. Morales Fuentes, D.I. Wilson Jul 2007

Simultaneous Consideration Of Flow And Thermal Effects Of Fouling In Crude Oil Preheat Trains, G.T. Polley, A. Morales Fuentes, D.I. Wilson

Heat Exchanger Fouling and Cleaning VII

Given models linking flow resistance and fouling resistance it becomes possible to simulate the effects of fouling on the hydraulic performance of a refinery pre-heat train. Such a simulation has been used here to identify when plant throughput will be limited by pressure drop; how throughput can be improved through the cleaning of individual exchangers and groups of exchangers; and how much production can be maintained when individual exchangers are taken off-line. Determination of better operating strategy requires a simulation of both hydraulic and thermal performance. In this paper we implement a pragmatic linked model and consider the results from …

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Optimization Of Flow Direction To Minimize Particulate Fouling Of Heat Exchangers, M.S. Abd-Elhady, C.C.M. Rindt, A.A. Van Steenhoven Jul 2007

Optimization Of Flow Direction To Minimize Particulate Fouling Of Heat Exchangers, M.S. Abd-Elhady, C.C.M. Rindt, A.A. Van Steenhoven

Heat Exchanger Fouling and Cleaning VII

The influence of flow direction with respect to gravity on particulate fouling of heat exchangers is investigated experimentally to determine the optimal flow direction to minimize fouling. Four orientations of flow have been investigated, horizontal flow, upward flow, downward flow and a flow under an angle of 45°. It is observed that fouling starts at the point of stagnation irrespective of the flow direction, and also at the top of the heat exchanger tubes. Particulate fouling grows from these two points till they meet and the fouling layer covers the whole surface of the heat exchanger tube. Fouling at the …

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Incorporation Of A Consideration Of Fouling Into The Design Of Vertical Thermo-Siphon Re-Boilers, G.T. Polley, S.J. Pugh Jul 2007

Incorporation Of A Consideration Of Fouling Into The Design Of Vertical Thermo-Siphon Re-Boilers, G.T. Polley, S.J. Pugh

Heat Exchanger Fouling and Cleaning VII

Two causes of under-performance within the tubes of vertical thermo-siphon re-boilers (VTR’s) are considered: premature dry-out within the unit and chemical reaction fouling at the tube wall. In many cases dryout is itself a cause of fouling. Both of these causes depend on re-boiler geometry. Some geometry performs satisfactorily. Other geometry performs poorly. There are two basic forms of flow boiling: nucleate flow boiling and convective flow boiling. In nucleate flow boiling part of the vaporisation results from the formation of bubbles of vapour on the heated surface. Unfortunately, a thin liquid film (the micro-layer) formed beneath these bubbles can …

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A Lagrangian Particle Cfd Post-Processor Dedicated To Particle Adhesion/Deposition, M. Losurdo, C. Bertrand, H. Spliethoff Jul 2007

A Lagrangian Particle Cfd Post-Processor Dedicated To Particle Adhesion/Deposition, M. Losurdo, C. Bertrand, H. Spliethoff

Heat Exchanger Fouling and Cleaning VII

In the past few years the use of biomass in power plants has grown dramatically. As a result of this action fouling and slagging in co-firing biomass facilities have turned out to play a critical role in the efficiency of such facilities. Efficient and effective methods are therefore needed to control fouling to an acceptable level and to prevent economic losses due to reduced furnace thermal efficiency, increased maintenance or even unscheduled outages. Numerical prediction of the impact of deposit properties has proved itself to be a successful strategy to both evaluate changes in the facility performance and to investigate …

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A Survey Of Alfa Laval’S Experience Of Fouling Prevention In Plate Heat Exchanger Systems, A. Tornqvist Jul 2007

A Survey Of Alfa Laval’S Experience Of Fouling Prevention In Plate Heat Exchanger Systems, A. Tornqvist

Heat Exchanger Fouling and Cleaning VII

This paper will present some aspects on and experiences of fouled plate heat exchangers in industrial applications as well as the present status on a new tool to monitor heat exchanger performance and to predict future cleaning procedures.

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Computation And Evaluation Of Wall Shear Stress Distribution At The Lower Surface Of A Radial Flow Cell, J. G. Detry, B. B. B. Jensen, C. Deroanne, M. Sindic Jul 2007

Computation And Evaluation Of Wall Shear Stress Distribution At The Lower Surface Of A Radial Flow Cell, J. G. Detry, B. B. B. Jensen, C. Deroanne, M. Sindic

Heat Exchanger Fouling and Cleaning VII

In the present work, the flow in the radial-flow cell was analyzed for an aspect ratio of 1 with inlet pipe Reynolds numbers of 950, 2 000 and 4 100. Two models were applied to compute the wall shear stress distribution at the lower surface, at any distance from the center. Stainless steel and polystyrene surfaces were soiled with oil and starch and the detachment of these soils was assessed by measuring the detachment radius in a radial-flow cell. The experimental radii were introduced in the models and converted into wall shear stress. Comparisons of the various sets of data …

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Effect Of Thermal Contact Resistance On The Heat Transfer In Plate Finned Tube Heat Exchangers, D. Taler Jul 2007

Effect Of Thermal Contact Resistance On The Heat Transfer In Plate Finned Tube Heat Exchangers, D. Taler

Heat Exchanger Fouling and Cleaning VII

Plate fin-and-tube heat exchangers are made by inserting oval tubes through sheet metal strips with stamped holes and then expanding the tubes slightly to cause pressure at the tube-to-strip contacts. The gap between the fin base and the outer tube surface may be filled with air or corrosion products causing a decline in the ability of plate fins to transfer heat. The contact resistance must be accounted for in the design and performance calculations of heat exchangers. In this paper, the thermal contact resistance of the fin-to-tube attachment is estimated from the condition that the dimensionless correlations for the Colburn …

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Low Fouling Crude Oil Preheaters: Scrap Your Existing Conventional Crude Oil Preheaters, Replace Them By Low Fouling Heat Exchangers And Save Money, D.G. Klaren, E.F. De Boer, D.W. Sullivan Jul 2007

Low Fouling Crude Oil Preheaters: Scrap Your Existing Conventional Crude Oil Preheaters, Replace Them By Low Fouling Heat Exchangers And Save Money, D.G. Klaren, E.F. De Boer, D.W. Sullivan

Heat Exchanger Fouling and Cleaning VII

In a time that crude oil prices are constantly higher than US$ 60 per barrel, low fouling heat exchangers can reduce total fouling cost in all crude oil preheat trains in the world with a throughput of 74 Mn bpd by 90%. For 2006, this is a reduction from approximately US$ 11 Bn to US$ 1.3 Bn and a saving on annual fouling cost of US$ 9.7 Bn. Besides this saving on fouling cost, substantial additional savings can be realized on energy by a more ‘energy efficient’ design of the crude oil preheat train. The advantages of the low fouling …

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Intelligent Discrimination Model To Identify Influential Parameters During Crystallisation Fouling, M.R. Malayeri, H. Müller-Steinhagen Jul 2007

Intelligent Discrimination Model To Identify Influential Parameters During Crystallisation Fouling, M.R. Malayeri, H. Müller-Steinhagen

Heat Exchanger Fouling and Cleaning VII

The introduction of redundant independent variables into any function approximation model, or the neglect of important variables, may result in a correlation with poor prediction and reduced reliability. This paper demonstrates that a novel integrated model of neural networks and genetic algorithms can deal with this problem robustly with good accuracy, while be far less time-consuming compared to lengthy conventional models Furthermore, a redundant variable input was imposed to the model to discern if the approach could identify it among other important variables. Genetic algorithms were exploited as a powerful optimisation tool for the selection of best set of inputs …

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Fluid Dynamic Gauging In Duct Flows – Experiments And Cfd Simulations, T. Gu, Y.M.J. Chew, W.R. Paterson, D.I. Wilson Jul 2007

Fluid Dynamic Gauging In Duct Flows – Experiments And Cfd Simulations, T. Gu, Y.M.J. Chew, W.R. Paterson, D.I. Wilson

Heat Exchanger Fouling and Cleaning VII

The technique of fluid dynamic gauging (FDG) has been developed to measure the thickness of deformable foulant deposits on solid immersed in liquid, in real time and in situ, with a precision of ± 10 micron. Suction is imposed across a gauging nozzle; the flow rate of liquid through the nozzle allows calculation of the proximity of the nozzle to the surface of the deposit. The technique has been demonstrated by Tuladhar et al. (2000) to work well in quasi-static situations, where the bulk liquid is not moving apart from the gauging flow, and in duct flows. FDG in the …

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Fouling During The Use Of ‘Fresh’ Water As Coolant- The Development Of A ‘User Guide’, S. J. Pugh, G. F. Hewitt, H. Müller-Steinhagen Jul 2007

Fouling During The Use Of ‘Fresh’ Water As Coolant- The Development Of A ‘User Guide’, S. J. Pugh, G. F. Hewitt, H. Müller-Steinhagen

Heat Exchanger Fouling and Cleaning VII

IHS ESDU recently published its latest ‘User Guide’ to fouling in heat exchange systems, for systems with fresh water as the coolant. ESDU 07006 [1] is the third in a group, following the development of the Crude Oil Fouling User Guide [2] issued in 2000 and the Seawater Fouling User Guide [3] issued in 2004. ESDU 07006 was developed by IHS ESDU over a period of five years under the guidance of the Oil Industry Fouling Working Party, a collaborative team of oil refiners, heat transfer equipment and services suppliers and Universities. It provides designers and operators of cooling water …

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Achievements And Potential Of Self-Cleaning Heat Exchangers Using Untreated Natural Seawater As A Coolant, D.G. Klaren, E.F. De Boer Jul 2007

Achievements And Potential Of Self-Cleaning Heat Exchangers Using Untreated Natural Seawater As A Coolant, D.G. Klaren, E.F. De Boer

Heat Exchanger Fouling and Cleaning VII

The fluidized bed self-cleaning heat exchange technology has been developed in the 70s for the application in thermal desalination plants, like Multi-Stage Flash (MSF) evaporators. This paper summarizes the achievements of the Multi-Stage Flash / Fluidized Bed Evaporator (MSF/FBE) in the past, but also pays attention to its market potential today, whether or not in combination with the possible revamp of existing conventional MSF plants into a better performing configuration. Further, this paper also pays attention to the application of the self-cleaning heat exchange technology for closedloop coolers or so-called ‘mother-coolers’ for large chemical plants. Last but not least, attention …

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Influence Of Different Surface Materials On The Fouling Process In A Microstructured Heat Exchanger Under Laminar Regime, W. Benzinger, J.J. Brandner, U. Schygulla, K. Schubert Jul 2007

Influence Of Different Surface Materials On The Fouling Process In A Microstructured Heat Exchanger Under Laminar Regime, W. Benzinger, J.J. Brandner, U. Schygulla, K. Schubert

Heat Exchanger Fouling and Cleaning VII

Microstructure devices are well known for their excellent performance with regard to heat and mass transfer. Microstructured heat exchangers show significant advantages in comparison with conventional heat exchangers. The unique properties of a microreaction system show high overall heat transfer coefficients for example. Small characteristic dimensions are in the order of a few hundred μm (Schubert et al., 1998, 2001; Worz et al, 1998). Due to the small dimensions, an increased pressure drop is combined with excellent heat transfer properties. But the small channels are prone to fouling processes. The accumulation of crystalline deposits is a severe problem. An additional …

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Cleaning And Prevention Of Inorganic Deposits In Plate Heat Exchangers Using Pulsating Current, A. Pehkonen, J. Aromaa, O. Forsén, J. Virtanen, I. Galfi Jul 2007

Cleaning And Prevention Of Inorganic Deposits In Plate Heat Exchangers Using Pulsating Current, A. Pehkonen, J. Aromaa, O. Forsén, J. Virtanen, I. Galfi

Heat Exchanger Fouling and Cleaning VII

Fouling of heat exchangers is a major problem in many industrial processes. The higher temperature of the heat exchange surface compared with the liquid containing precipitable compounds causes the formation of inorganic deposits. Removing the deposits on plate heat exchangers is most often carried out by high-pressure cleaning. This is a laborious task and often increases the corrosion rate of the plates by increasing the roughness of the cleaned surface. This study presents an electrochemical method to clean heat exchange surfaces fouled by deposits and to prevent formation of deposits. This method utilizes pulsating current to polarize heat exchange surfaces …

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Hitran® Wire Matrix Inserts In Fouling Applications, J.M. Ritchie, P. Droegemueller, M.J.H. Simmons Jul 2007

Hitran® Wire Matrix Inserts In Fouling Applications, J.M. Ritchie, P. Droegemueller, M.J.H. Simmons

Heat Exchanger Fouling and Cleaning VII

Fouling characteristics are dictated largely by the properties of the thermal and hydrodynamic boundary layers. As a result, fouling mitigation strategies must take into account the conditions in this region. hiTRAN® wire matrix tube inserts are a useful tool in altering the conditions near the tube wall, especially in the laminar and transition flow regions. This review paper considers Particle Image Velocimetry (PIV) and Laser Doppler Velocimetry (LDV) measurements, which were employed in order to show the hydrodynamic differences between plain tubes and those containing inserts. Measurements indicate that the wall shear rate in tubes containing hiTRAN® inserts operating in …

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Automatic Tube Cleaning System (Atcs) Installation In Sulfide Retrieval Monoethanolamine Treatment Plant: Case Study And Fouling Global Perspectives, Chemi Sugarmen, Udi Siboni, Ruth Volansky Jul 2007

Automatic Tube Cleaning System (Atcs) Installation In Sulfide Retrieval Monoethanolamine Treatment Plant: Case Study And Fouling Global Perspectives, Chemi Sugarmen, Udi Siboni, Ruth Volansky

Heat Exchanger Fouling and Cleaning VII

Automatic cleaning of heat exchangers and condensers tubes by means of sponge balls is well known since the early fifties, with expanding application from steam power plants to process industry to industrial cooling and air conditioning systems. Main benefits bottom-lined in cost savings are generally considered as: elimination of maintenance down-time and need for chemical and more efficient operation of process and plant. This paper presents the performance and benefits of an Automatic Tube Cleaning System (ATCS) implementations, in a hydrogen sulfide retrieval Monoethanolamine treatment Plant in Paz Ashdod Refinery, one of the two refineries in Israel. Patented by CQM …

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