Search results for: Impinging streams reactor
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 456

Search results for: Impinging streams reactor

456 Residence Time Distribution in a Two Impinging Streams Cyclone Reactor: CFD Prediction and Experimental Validation

Authors: Nahid Ghasemi, Morteza Sohrabi, Yasan Soleymani

Abstract:

The quantified residence time distribution (RTD) provides a numerical characterization of mixing in a reactor, thus allowing the process engineer to better understand mixing performance of the reactor.This paper discusses computational studies to investigate flow patterns in a two impinging streams cyclone reactor(TISCR) . Flow in the reactor was modeled with computational fluid dynamics (CFD). Utilizing the Eulerian- Lagrangian approach, implemented in FLUENT (V6.3.22), particle trajectories were obtained by solving the particle force balance equations. From simulation results obtained at different Δts, the mean residence time (tm) and the mean square deviation (σ2) were calculated. a good agreement can be observed between predicted and experimental data. Simulation results indicate that the behavior of complex reactor systems can be predicted using the CFD technique with minimum data requirement for validation.

Keywords: Impinging streams reactor, Residence timedistribution, CFD, Eulerian-Lagrangian approach

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455 Parametric Study of Confined Turbulent Impinging Slot Jets upon a Flat Plate

Authors: A. M. Tahsini, S. Tadayon Mousavi

Abstract:

In the present paper, a numerical investigation has been carried out to classify and clarify the effects of paramount parameters on turbulent impinging slot jets. The effects of nozzle-s exit turbulent intensity, distance between nozzle and impinging plate are studied at Reynolds number 5000 and 20000. In addition, the effect of Mach number that is varied between 0.3-0.8 at a constant Reynolds number 133000 is investigated to elucidate the effect of compressibility in impinging jet upon a flat plate. The wall that is located at the same level with nozzle-s exit confines the flow. A compressible finite volume solver is implemented for simulation the flow behavior. One equation Spalart-Allmaras turbulent model is used to simulate turbulent flow at this study. Assessment of the Spalart-Allmaras turbulent model at high nozzle to plate distance, and giving enough insights to characterize the effect of Mach number at high Reynolds number for the complex impinging jet flow are the remarkable results of this study.

Keywords: Impinging jet, Numerical simulation, Turbulence.

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454 Heat Transfer of an Impinging Jet on a Plane Surface

Authors: Jian-Jun Shu

Abstract:

A cold, thin film of liquid impinging on an isothermal hot, horizontal surface has been investigated. An approximate solution for the velocity and temperature distributions in the flow along the horizontal surface is developed, which exploits the hydrodynamic similarity solution for thin film flow. The approximate solution may provide a valuable basis for assessing flow and heat transfer in more complex settings.

Keywords: Flux, free impinging jet, solid-surface, uniform wall temperature.

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453 Large-Eddy Simulations of Subsonic Impinging Jets

Authors: L. Nguyen, V. Golubev, R. Mankbadi

Abstract:

We consider here the subsonic impinging jet representing the flow field of a vertical take-off aircraft or the initial stage of rocket launching. Implicit Large-Eddy Simulation (ILES) is used to calculate the time-dependent flow field and the radiate sound pressure associated with jet impinging. With proper boundary treatments and high-order numerical scheme, the near field sound pressure is successfully obtained. Results are presented for both a rectangular as well a circular jet.

Keywords: Aeroacoustics, Large-Eddy Simulations, Jets, Fluid Dynamics.

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452 Laminar Impinging Jet Heat Transfer for Curved Plates

Authors: A. M. Tahsini, S. Tadayon Mousavi

Abstract:

The purpose of the present study is to analyze the effect of the target plate-s curvature on the heat transfer in laminar confined impinging jet flows. Numerical results from two dimensional compressible finite volume solver are compared between three different shapes of impinging plates: Flat, Concave and Convex plates. The remarkable result of this study proves that the stagnation Nusselt number in laminar range of Reynolds number based on the slot width is maximum in convex surface and is minimum in concave plate. These results refuse the previous data in literature stating the amount of the stagnation Nusselt number is greater in concave surface related to flat plate configuration.

Keywords: Concave, Convex, Heat transfer, Impinging jet, Laminar flow.

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451 A Numerical Study on Heat Transfer in Laminar Pulsed Slot Jets Impinging on a Surface

Authors: D. Kim

Abstract:

Numerical simulations are performed for laminar continuous and pulsed jets impinging on a surface in order to investigate the effects of pulsing frequency on the heat transfer characteristics. The time-averaged Nusselt number of pulsed jets is larger in the impinging jet region as compared to the continuous jet, while it is smaller in the outer wall jet region. At the stagnation point, the mean and RMS Nusselt numbers become larger and smaller, respectively, as the pulsing frequency increases. Unsteady behaviors of vortical fluid motions and temperature field are also investigated to understand the underlying mechanisms of heat transfer enhancement.

Keywords: Pulsed slot jet, impingement, pulsing frequency, heat transfer enhancement.

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450 A New History Based Method to Handle the Recurring Concept Shifts in Data Streams

Authors: Hossein Morshedlou, Ahmad Abdollahzade Barforoush

Abstract:

Recent developments in storage technology and networking architectures have made it possible for broad areas of applications to rely on data streams for quick response and accurate decision making. Data streams are generated from events of real world so existence of associations, which are among the occurrence of these events in real world, among concepts of data streams is logical. Extraction of these hidden associations can be useful for prediction of subsequent concepts in concept shifting data streams. In this paper we present a new method for learning association among concepts of data stream and prediction of what the next concept will be. Knowing the next concept, an informed update of data model will be possible. The results of conducted experiments show that the proposed method is proper for classification of concept shifting data streams.

Keywords: Data Stream, Classification, Concept Shift, History.

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449 Numerical Studies on Thrust Vectoring Using Shock-Induced Self Impinging Secondary Jets

Authors: S. Vignesh, N. Vishnu, S. Vigneshwaran, M. Vishnu Anand, Dinesh Kumar Babu, V. R. Sanal Kumar

Abstract:

Numerical studies have been carried out using a validated two-dimensional standard k-omega turbulence model for the design optimization of a thrust vector control system using shock induced self-impinging supersonic secondary double jet. Parametric analytical studies have been carried out at different secondary injection locations to identifying the highest unsymmetrical distribution of the main gas flow due to shock waves, which produces a desirable side force more lucratively for vectoring. The results from the parametric studies of the case on hand reveal that the shock induced self-impinging supersonic secondary double jet is more efficient in certain locations at the divergent region of a CD nozzle than a case with supersonic single jet with same mass flow rate. We observed that the best axial location of the self-impinging supersonic secondary double jet nozzle with a given jet interaction angle, built-in to a CD nozzle having area ratio 1.797, is 0.991 times the primary nozzle throat diameter from the throat location. We also observed that the flexible steering is possible after invoking ON/OFF facility to the secondary nozzles for meeting the onboard mission requirements. Through our case studies we concluded that the supersonic self-impinging secondary double jet at predesigned jet interaction angle and location can provide more flexible steering options facilitating with 8.81% higher thrust vectoring efficiency than the conventional supersonic single secondary jet without compromising the payload capability of any supersonic aerospace vehicle.

Keywords: Fluidic thrust vectoring, rocket steering, self-impinging secondary supersonic jet, TVC in aerospace vehicles.

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448 Hydrodynamic Simulation of Fixed Bed GTL Reactor Using CFD

Authors: Sh. Shahhosseini, S. Alinia, M. Irani

Abstract:

In this work, axisymetric CFD simulation of fixed bed GTL reactor has been conducted, using computational fluid dynamics (CFD). In fixed bed CFD modeling, when N (tube-to-particle diameter ratio) has a large value, it is common to consider the packed bed as a porous media. Synthesis gas (a mixture of predominantly carbon monoxide and hydrogen) was fed to the reactor. The reactor length was 20 cm, divided to three sections. The porous zone was in the middle section of the reactor. The model equations were solved employing finite volume method. The effects of particle diameter, bed voidage, fluid velocity and bed length on pressure drop have been investigated. Simulation results showed these parameters could have remarkable impacts on the reactor pressure drop.

Keywords: GTL Process, Fixed bed reactor, Pressure drop, CFDsimulation.

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447 Partial Oxidation of Methane in the Pulsed Compression Reactor: Experiments and Simulation

Authors: Timo Roestenberg, Maxim Glushenkov, Alexander Kronberg, Anton A. Verbeek, Theo H. vd Meer

Abstract:

The Pulsed Compression Reactor promises to be a compact, economical and energy efficient alternative to conventional chemical reactors. In this article, the production of synthesis gas using the Pulsed Compression Reactor is investigated. This is done experimentally as well as with simulations. The experiments are done by means of a single shot reactor, which replicates a representative, single reciprocation of the Pulsed Compression Reactor with great control over the reactant composition, reactor temperature and pressure and temperature history. Simulations are done with a relatively simple method, which uses different models for the chemistry and thermodynamic properties of the species in the reactor. Simulation results show very good agreement with the experimental data, and give great insight into the reaction processes that occur within the cycle.

Keywords: Chemical reactors, Energy, Pulsed compressionreactor, Simulation

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446 Dynamic Modeling and Simulation of Heavy Paraffin Dehydrogenation Reactor for Selective Olefin Production in Linear Alkyl Benzene Production Plant

Authors: G. Zahedi, H. Yaghoobi

Abstract:

Modeling of a heterogeneous industrial fixed bed reactor for selective dehydrogenation of heavy paraffin with Pt-Sn- Al2O3 catalyst has been the subject of current study. By applying mass balance, momentum balance for appropriate element of reactor and using pressure drop, rate and deactivation equations, a detailed model of the reactor has been obtained. Mass balance equations have been written for five different components. In order to estimate reactor production by the passage of time, the reactor model which is a set of partial differential equations, ordinary differential equations and algebraic equations has been solved numerically. Paraffins, olefins, dienes, aromatics and hydrogen mole percent as a function of time and reactor radius have been found by numerical solution of the model. Results of model have been compared with industrial reactor data at different operation times. The comparison successfully confirms validity of proposed model.

Keywords: Dehydrogenation, fixed bed reactor, modeling, linear alkyl benzene.

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445 Pollutants Removal from Synthetic Wastewater by the Combined Electrochemical Sequencing Batch Reactor

Authors: Amin Mojiri, Akiyoshi Ohashi, Tomonori Kindaichi

Abstract:

Synthetic domestic wastewater was treated via combining treatment methods, including electrochemical oxidation, adsorption, and sequencing batch reactor (SBR). In the upper part of the reactor, an anode and a cathode (Ti/RuO2-IrO2) were organized in parallel for the electrochemical oxidation procedure. Sodium sulfate (Na2SO4) with a concentration of 2.5 g/L was applied as the electrolyte. The voltage and current were fixed on 7.50 V and 0.40 A, respectively. Then, 15% working value of the reactor was filled by activated sludge, and 85% working value of the reactor was added with synthetic wastewater. Powdered cockleshell, 1.5 g/L, was added in the reactor to do ion-exchange. Response surface methodology was employed for statistical analysis. Reaction time (h) and pH were considered as independent factors. A total of 97.0% biochemical oxygen demand, 99.9% phosphorous and 88.6% cadmium were eliminated at the optimum reaction time (80.0 min) and pH (6.4).

Keywords: Adsorption, electrochemical oxidation, metals, sequencing batch reactor.

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444 Dominant Flow Features of Two Inclined Impinging Jets Confined in Large Enclosure

Authors: T. Chammem, H. Mhiri, O. Vauquelin

Abstract:

The present study was provided to examine the vortical structures generated by two inclined impinging jets with experimental and numerical investigations. The jets are issuing with a pitch angle α=40° into a confined quiescent fluid. The experimental investigation on flow patterns was visualized by using olive particles injected into the jets illuminated by Nd:Yag laser light to reveal the finer details of the confined jets interaction. It was observed that two counter-rotating vortex pairs (CVPs) were generated in the near region. A numerical investigation was also performed. First, the numerical results were validates against the experimental results and then the numerical model was used to study the effect of section ratio on the evolution of the CVPs. Our results show promising agreement with experimental data, and indicate that our model has the potential to produce useful and accurate data regarding the evolution of CVPs.

Keywords: Inclined impinging jets, counter-rotating vortex pair, CFD, experimental investigation, section ratio.

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443 The Study of Super Hydrophobic Surfaces Using High Speed Shadowgraphy

Authors: D. Jasikova, M. Kotek, V. Kopecky

Abstract:

The aim of this article is the measurement of the basic characteristic of superhydrophobic surfaces using high speed shadowgraphy. Here we describe the novel patented system for the industrial production of superhydrophobic surfaces. These surfaces were investigated with two optically based measurement methods: impinging drop and inclined wall. The results of the visualization and analysis help to state the suitable sample with superhydrophobic properties for mathematic simulation.

Keywords: Antipearl effect, contact angle, hydrophobic, impinging drop, inclined wall, measurement, plasma, shadowgraphy, superhydrophobic surface.

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442 CFD Simulation of Fixed Bed Reactor in Fischer-Tropsch Synthesis of GTL Technology

Authors: Sh. Shahhosseini, S. Alinia, M. Irani

Abstract:

In this paper 2D Simulation of catalytic Fixed Bed Reactor in Fischer-Tropsch Synthesis of GTL technology has been performed utilizing computational fluid dynamics (CFD). Synthesis gas (a mixture of carbon monoxide and hydrogen) has been used as feedstock. The reactor was modeled and the model equations were solved employing finite volume method. The model was validated against the experimental data reported in literature. The comparison showed a good agreement between simulation results and the experimental data. In addition, the model was applied to predict the concentration contours of the reactants and products along the length of reactor.

Keywords: GTL, Fischer–Tropsch synthesis, Fixed Bed Reactor, CFD simulation.

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441 Generalized Predictive Control of Batch Polymerization Reactor

Authors: R. Khaniki, M.B. Menhaj, H. Eliasi

Abstract:

This paper describes the application of a model predictive controller to the problem of batch reactor temperature control. Although a great deal of work has been done to improve reactor throughput using batch sequence control, the control of the actual reactor temperature remains a difficult problem for many operators of these processes. Temperature control is important as many chemical reactions are sensitive to temperature for formation of desired products. This controller consist of two part (1) a nonlinear control method GLC (Global Linearizing Control) to create a linear model of system and (2) a Model predictive controller used to obtain optimal input control sequence. The temperature of reactor is tuned to track a predetermined temperature trajectory that applied to the batch reactor. To do so two input signals, electrical powers and the flow of coolant in the coil are used. Simulation results show that the proposed controller has a remarkable performance for tracking reference trajectory while at the same time it is robust against noise imposed to system output.

Keywords: Generalized Predictive Control (GPC), TemperatureControl, Global Linearizing Control (GLC), Batch Reactor.

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440 Generalized Predictive Control of Batch Polymerization Reactor

Authors: R. Khaniki, M.B. Menhaj, H. Eliasi

Abstract:

This paper describes the application of a model predictive controller to the problem of batch reactor temperature control. Although a great deal of work has been done to improve reactor throughput using batch sequence control, the control of the actual reactor temperature remains a difficult problem for many operators of these processes. Temperature control is important as many chemical reactions are sensitive to temperature for formation of desired products. This controller consist of two part (1) a nonlinear control method GLC (Global Linearizing Control) to create a linear model of system and (2) a Model predictive controller used to obtain optimal input control sequence. The temperature of reactor is tuned to track a predetermined temperature trajectory that applied to the batch reactor. To do so two input signals, electrical powers and the flow of coolant in the coil are used. Simulation results show that the proposed controller has a remarkable performance for tracking reference trajectory while at the same time it is robust against noise imposed to system output.

Keywords: Generalized Predictive Control (GPC), TemperatureControl, Global Linearizing Control (GLC), Batch Reactor.

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439 Hydrodynamic Analysis with Heat Transfer in Solid Gas Fluidized Bed Reactor for Solar Thermal Applications

Authors: Sam Rasoulzadeh, Atefeh Mousavi

Abstract:

Fluidized bed reactors are known as highly exothermic and endothermic according to uniformity in temperature as a safe and effective mean for catalytic reactors. In these reactors, a wide range of catalyst particles can be used and by using a continuous operation proceed to produce in succession. Providing optimal conditions for the operation of these types of reactors will prevent the exorbitant costs necessary to carry out laboratory work. In this regard, a hydrodynamic analysis was carried out with heat transfer in the solid-gas fluidized bed reactor for solar thermal applications. The results showed that in the fluid flow the input of the reactor has a lower temperature than the outlet, and when the fluid is passing from the reactor, the heat transfer happens between cylinder and solar panel and fluid. It increases the fluid temperature in the outlet pump and also the kinetic energy of the fluid has been raised in the outlet areas.

Keywords: Heat transfer, solar reactor, fluidized bed reactor, CFD.

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438 Enhancement of Impingement Heat Transfer on a Flat Plate with Ribs

Authors: M. Kito, M. Takezaki, T. Shakouchi, K. Tsujimoto, T. Ando

Abstract:

Impinging jets are widely used in industrial cooling systems for their high heat transfer characteristics at stagnation points. However, the heat transfer characteristics are low in the downstream direction. In order to improve the heat transfer coefficient further downstream, investigations introducing ribs on jet-cooled flat plates have been conducted. Most studies regarding the heat-transfer enhancement using a rib-roughened wall have dealt with the rib pitch. In this paper, we focused on the rib spacing and demonstrated that the rib spacing must be more than 6 times the nozzle width to improve heat transfer at Reynolds number Re=5.0×103 because it is necessary to have enough space to allow reattachment of flow behind the first rib.

Keywords: Forced convection, heat transfer, impinging jet cooling, rib roughened wall

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437 Influence of Vegetable Oil-Based Controlled Cutting Fluid Impinging Supply System on Micro Hardness in Machining of Ti-6Al-4V

Authors: Salah Gariani, Islam Shyha, Fawad Inam, Dehong Huo

Abstract:

A controlled cutting fluid impinging supply system (CUT-LIST) was developed to deliver an accurate amount of cutting fluid into the machining zone via well-positioned coherent nozzles based on a calculation of the heat generated. The performance of the CUT-LIST was evaluated against a conventional flood cutting fluid supply system during step shoulder milling of Ti-6Al-4V using vegetable oil-based cutting fluid. In this paper, the micro-hardness of the machined surface was used as the main criterion to compare the two systems. CUT-LIST provided significant reductions in cutting fluid consumption (up to 42%). Both systems caused increased micro-hardness value at 100 µm from the machined surface, whereas a slight reduction in micro-hardness of 4.5% was measured when using CUL-LIST. It was noted that the first 50 µm is the soft sub-surface promoted by thermal softening, whereas down to 100 µm is the hard sub-surface caused by the cyclic internal work hardening and then gradually decreased until it reached the base material nominal hardness. It can be concluded that the CUT-LIST has always given lower micro-hardness values near the machined surfaces in all conditions investigated.

Keywords: Impinging supply system, micro-hardness, shoulder milling, Ti-6Al-4V, vegetable oil-based cutting fluid.

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436 Heat Transfer Analysis of a Multiphase Oxygen Reactor Heated by a Helical Tube in the Cu-Cl Cycle of a Hydrogen Production

Authors: Mohammed W. Abdulrahman

Abstract:

In the thermochemical water splitting process by Cu-Cl cycle, oxygen gas is produced by an endothermic thermolysis process at a temperature of 530oC. Oxygen production reactor is a three-phase reactor involving cuprous chloride molten salt, copper oxychloride solid reactant and oxygen gas. To perform optimal performance, the oxygen reactor requires accurate control of heat transfer to the molten salt and decomposing solid particles within the thermolysis reactor. In this paper, the scale up analysis of the oxygen reactor that is heated by an internal helical tube is performed from the perspective of heat transfer. A heat balance of the oxygen reactor is investigated to analyze the size of the reactor that provides the required heat input for different rates of hydrogen production. It is found that the helical tube wall and the service side constitute the largest thermal resistances of the oxygen reactor system. In the analysis of this paper, the Cu-Cl cycle is assumed to be heated by two types of nuclear reactor, which are HTGR and CANDU SCWR. It is concluded that using CANDU SCWR requires more heat transfer rate by 3-4 times than that when using HTGR. The effect of the reactor aspect ratio is also studied and it is found that increasing the aspect ratio decreases the number of reactors and the rate of decrease in the number of reactors decreases by increasing the aspect ratio. Comparisons between the results of this study and pervious results of material balances in the oxygen reactor show that the size of the oxygen reactor is dominated by the heat balance rather than the material balance.

Keywords: Heat transfer, Cu-Cl cycle, hydrogen production, oxygen, clean energy.

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435 Content Based Sampling over Transactional Data Streams

Authors: Mansour Tarafdar, Mohammad Saniee Abade

Abstract:

This paper investigates the problem of sampling from transactional data streams. We introduce CFISDS as a content based sampling algorithm that works on a landmark window model of data streams and preserve more informed sample in sample space. This algorithm that work based on closed frequent itemset mining tasks, first initiate a concept lattice using initial data, then update lattice structure using an incremental mechanism.Incremental mechanism insert, update and delete nodes in/from concept lattice in batch manner. Presented algorithm extracts the final samples on demand of user. Experimental results show the accuracy of CFISDS on synthetic and real datasets, despite on CFISDS algorithm is not faster than exist sampling algorithms such as Z and DSS.

Keywords: Sampling, data streams, closed frequent item set mining.

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434 Optical Analysis of Variable Aperture Mechanism for a Solar Reactor

Authors: Akanksha Menon, Nesrin Ozalp

Abstract:

Solar energy is not only sustainable but also a clean alternative to be used as source of high temperature heat for many processes and power generation. However, the major drawback of solar energy is its transient nature. Especially in solar thermochemical processing, it is crucial to maintain constant or semiconstant temperatures inside the solar reactor. In our laboratory, we have developed a mechanism allowing us to achieve semi-constant temperature inside the solar reactor. In this paper, we introduce the concept along with some updated designs and provide the optical analysis of the concept under various incoming flux.

Keywords: Aperture, Solar reactor, Optical analysis, Solar thermal

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433 Shot Transition Detection with Minimal Decoding of MPEG Video Streams

Authors: Mona A. Fouad, Fatma M. Bayoumi, Hoda M. Onsi, Mohamed G. Darwish

Abstract:

Digital libraries become more and more necessary in order to support users with powerful and easy-to-use tools for searching, browsing and retrieving media information. The starting point for these tasks is the segmentation of video content into shots. To segment MPEG video streams into shots, a fully automatic procedure to detect both abrupt and gradual transitions (dissolve and fade-groups) with minimal decoding in real time is developed in this study. Each was explored through two phases: macro-block type's analysis in B-frames, and on-demand intensity information analysis. The experimental results show remarkable performance in detecting gradual transitions of some kinds of input data and comparable results of the rest of the examined video streams. Almost all abrupt transitions could be detected with very few false positive alarms.

Keywords: Adaptive threshold, abrupt transitions, gradual transitions, MPEG video streams.

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432 Hydraulic Studies on Core Components of PFBR

Authors: G. K. Pandey, D. Ramadasu, I. Banerjee, V. Vinod, G. Padmakumar, V. Prakash, K. K. Rajan

Abstract:

Detailed thermal hydraulic investigations are very  essential for safe and reliable functioning of liquid metal cooled fast  breeder reactors. These investigations are further more important for  components with complex profile, since there is no direct correlation  available in literature to evaluate the hydraulic characteristics of such  components directly. In those cases available correlations for similar  profile or geometries may lead to significant uncertainty in the  outcome. Hence experimental approach can be adopted to evaluate  these hydraulic characteristics more precisely for better prediction in  reactor core components.  Prototype Fast Breeder Reactor (PFBR), a sodium cooled pool  type reactor is under advanced stage of construction at Kalpakkam,  India. Several components of this reactor core require hydraulic  investigation before its usage in the reactor. These hydraulic  investigations on full scale models, carried out by experimental  approaches using water as simulant fluid are discussed in the paper. 

Keywords: Fast Breeder Reactor, Cavitation, pressure drop, Reactor components.

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431 Mining Big Data in Telecommunications Industry: Challenges, Techniques, and Revenue Opportunity

Authors: Hoda A. Abdel Hafez

Abstract:

Mining big data represents a big challenge nowadays. Many types of research are concerned with mining massive amounts of data and big data streams. Mining big data faces a lot of challenges including scalability, speed, heterogeneity, accuracy, provenance and privacy. In telecommunication industry, mining big data is like a mining for gold; it represents a big opportunity and maximizing the revenue streams in this industry. This paper discusses the characteristics of big data (volume, variety, velocity and veracity), data mining techniques and tools for handling very large data sets, mining big data in telecommunication and the benefits and opportunities gained from them.

Keywords: Mining Big Data, Big Data, Machine learning, Data Streams, Telecommunication.

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430 Design of Laboratory Pilot Reactor for Filtering and Separation of Water – oil Emulsions

Authors: Irena Markovska, Nikolai Zaicev, Bogdan Bogdanov, Dimitar Georgiev, Yancho Hristov

Abstract:

The present paper deals with problems related to the possibilities to use fractal systems to solve some important scientific and practical problems connected with filtering and separation of aqueous phases from organic ones. For this purpose a special separator have been designed. The reactor was filled with a porous material with fractal dimension, which is an integral part of the set for filtration and separation of emulsions. As a model emulsion hexadecan mixture with water in equal quantities (1:1) was used. We examined the hydrodynamics of the separation of the emulsion at different rates of submission of the entrance of the reactor.

Keywords: pilot reactor, fractal systems, separation, emulsions

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429 Reduction of Energy Consumption of Distillation Process by Recovering the Heat from Exit Streams

Authors: Apichit Svang-Ariyaskul, Thanapat Chaireongsirikul, Pawit Tangviroon

Abstract:

Distillation consumes enormous quantity of energy. This work proposed a process to recover the energy from exit streams during the distillation process of three consecutive columns. There are several novel techniques to recover the heat with the distillation system; however, a complex control system is required. This work proposed a simpler technique by exchanging the heat between streams without interrupting the internal distillation process that might cause a serious control problem. The proposed process is executed by using heat exchanger network with pinch analysis to maximize the process heat recovery. The test model is the distillation of butane, pentane, hexane, and heptanes, which is a common mixture in the petroleum refinery. This proposed process saved the energy consumption for hot and cold utilities of 29 and 27%, which is considered significant. Therefore, the recovery of heat from exit streams from distillation process is proved to be effective for energy saving.

Keywords: Distillation, Heat Exchanger, Network Pinch Analysis.

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428 Aspen Plus Simulation of Saponification of Ethyl Acetate in the Presence of Sodium Hydroxide in a Plug Flow Reactor

Authors: U. P. L. Wijayarathne, K. C. Wasalathilake

Abstract:

This work presents the modelling and simulation of saponification of ethyl acetate in the presence of sodium hydroxide in a plug flow reactor using Aspen Plus simulation software. Plug flow reactors are widely used in the industry due to the non-mixing property. The use of plug flow reactors becomes significant when there is a need for continuous large scale reaction or fast reaction. Plug flow reactors have a high volumetric unit conversion as the occurrence for side reactions is minimum. In this research Aspen Plus V8.0 has been successfully used to simulate the plug flow reactor. In order to simulate the process as accurately as possible HYSYS Peng- Robinson EOS package was used as the property method. The results obtained from the simulation were verified by the experiment carried out in the EDIBON plug flow reactor module. The correlation coefficient (r2) was 0.98 and it proved that simulation results satisfactorily fit for the experimental model. The developed model can be used as a guide for understanding the reaction kinetics of a plug flow reactor.

Keywords: Aspen Plus, Modelling, Plug Flow Reactor, Simulation.

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427 Simulation Design of Separator for the Treatment of Emulsions

Authors: Irena Markovska, Dimitar Rusev, Nikolai Zaicev, Bogdan Bogdanov, Dimitar Georgiev, Yancho Hristov

Abstract:

A prototype model of an emulsion separator was designed and manufactured. Generally, it is a cylinder filled with different fractal modules. The emulsion was fed into the reactor by a peristaltic pump through an inlet placed at the boundary between the two phases. For hydrodynamic design and sizing of the reactor the assumptions of the theory of filtration were used and methods to describe the separation process were developed. Based on this methodology and using numerical methods and software of Autodesk the process is simulated in different operating modes. The basic hydrodynamic characteristics - speed and performance for different types of fractal systems and decisions to optimize the design of the reactor were also defined.

Keywords: fractal systems, reactor, separation, emulsions

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