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Article
Prediction of Mass Transfer Coefficient in Bubble Column Using Artificial Neural Network

Authors: Salih A. Salih --- Adil A. Al-Hemiri
Journal: Journal of Engineering مجلة الهندسة ISSN: 17264073 25203339 Year: 2007 Volume: 13 Issue: 2 Pages: 1327-1342
Publisher: Baghdad University جامعة بغداد

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Abstract

The volumetric mass transfer coefficient kL.a was calculated using two gases (air and CO2) in water and NaOH solution. The experiments were carried out using 0.1 m column diameter. Empirical and Artificial Neural Network (ANN) correlation were developed to predicted mass transfer coefficient in form of dimensionless groups (Sh, Re,Bo and We). The use of Back Propagation Neural Network (BPNN) gave better results than other correlations found in literature and than the empirical one found in this study.

تمت دراسة معامل الانتقال الحجمي في عمود فقاعي ذو قطر 0.1 متر يحتوي على موزع للغاز ذو 79 فتحة بقطر 2 مليمتر لكل فتحة باستخدام الهواء و ثاني اوكسيد الكاربون للطور الغازي و الماء ومحلول هيدروكسيد الصوديوم للطور السائل.تم تطوير معادلة عامة وإستخدام الشبكة الذكية المصطنعة ( ANN) لحساب معامل انتقال الكتلة الحجمي من خلال استخدام مجاميع عديمة الوحدات ( We,Sh,Re,Bo ). إستخدام الشبكة الذكية من نوع التوالد العكسي ( BPNN ) اعطى نتائج متميزة احسن من تلك الموجودة في الادبيات.


Article
ESTIMATION OF MASS TRANSFER COEFFICIENTS IN A PACKED DISTILLATION COLUMN USING BATCH MODE

Authors: Mohammed D. Selman --- Adil A. Al-Hemiri عادل احمد عوض
Journal: Iraqi Journal of Chemical and Petroleum Engineering المجلة العراقية للهندسة الكيمياوية وهندسة النفط ISSN: 19974884/E26180707 Year: 2011 Volume: 12 Issue: 1 Pages: 13-21
Publisher: Baghdad University جامعة بغداد

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Abstract

This research adopts the estimation of mass transfer coefficient in batch packed bed distillation column as function of physical properties, liquid to vapour molar rates ratio (L / V), relative volatility (α), ratio of vapour and liquid diffusivities (DV / DL), ratio of vapour and liquid densities (ρV / ρL), ratio of vapour and liquid viscosities (µV/ µL). The experiments are done using binary systems, (Ethanol Water), (Methanol Water), (Methanol Ethanol), (Benzene Hexane), (Benzene Toluene). Statistical program (multiple regression analysis) is used for estimating the overall mass transfer coefficient of vapour and liquid phases (KOV and KOL) in a correlation which represented the data fairly well.KOV = 3.3 * 10-10 α-0.7 (DV / DL) 0.65 (L / V) 3.5 (ρV / ρL) 1.25 (μV / μL) -5.0KOL = 2.8 * 10-6 α-0.95 (DV / DL) 0.03 (L / V) 1.15 (ρV / ρL )0.077 (μV / μL) -0.9 In this research a method where the resistances to mass transfer in both phases are accounted for separately through the use of HTU-NTU model for each phase Z=HTUOV.NTUOV and Z=HTUOL.NTUOL Results show that both overall vapour and liquid mass transfer coefficient are increased with liquid to vapour molar rates ratio, vapour to liquid diffusivities ratio and vapor to liquid densities ratio, but decreased with increasing the relative volatility and vapour to liquid viscosities ratio.


Article
Prediction Of The Efficiency Of Sieve Tray Using Air-Water System

Authors: Muhannad Abdul Razaq Hassan --- Adil A. Al-Hemiri
Journal: Journal of Engineering مجلة الهندسة ISSN: 17264073 25203339 Year: 2006 Volume: 12 Issue: 4 Pages: 941-956
Publisher: Baghdad University جامعة بغداد

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Abstract

This investigation deals with the effect of weir height, liquid and gas flow rate on tray efficiency. The tests were carried out on a single pass cross flow tray of air-water system of 0.3 m diameter for clear liquid height over sieve tray with weir height 3, 4 and 5 cm.Point efficiency values were found to be in the same range for different weir height, but it improves slightly with weir height. And the average values of point efficiency were 83 % for 3 cm weir height, 85 % for 4 cm weir height and 89 % for 5 cm weir height. While, point efficiency of 90 % was obtained for 5 cm weir height and liquid flow rate ranging between 5.8 to 7.32 m3/s. In the range of clear liquid height over hole diameter ( hL/dH) between 2 to 10, increasing the Reynolds number ranging between 2.0*105 to 1.6*106 for gas phase increases point efficiency.Prediction of Murphree (Tray) efficiency using Lopez and Castells (1999) equation shows that the ratio of EMV/Ep is equal to 1, due to low value of calculated Peclet number (degree of liquid mixing), which ranged between 0.07 to 1.5.

درس هذا البحث تاثير تغير كل من إرتفاع السد و جريان السائل و الغاز على إرتفاع السائل فوق الصينية المنخلية و كفائتها لنظام هواء-ماء. يزداد ارتفاع السائل فوق صينية اختبار واحدة ذات قطر0.3 متر وعدد فتحات 213 فتحة و ارتفاع سد3 و4 و5 سم بزيادة جريان السائل بين 0.12 الى 0.58 متر مكعب ساعة ويقل مع زيادة جريان الغاز من 35 الى 100 متر مكعب ساعة. كانت قيم الكفاء ة النقطية متقاربة لكنها تتحسن قليلا مع زيادة ارتفاع السد . وكانت معدلاتها مع ارتفاع السد هي 83% لارتفاع سد3 سم و85% لارتفاع سد 4 سم و 89% لارتفاع سد 5 سم . في حين اعلى قيمة للكفاءة النقطية كانت 90% لارتفاع سد 5 سم و جريان ماء بين 8.5 و 7.32 م3 / ثا . كذلك زيادة عدد رينولدز للطور الغازي يزيد من الكفاءة النقطية للصواني المنخلية في حالة كون نسبة إرتفاع السائل إلى قطر ثقب الصينية تتراوح بين 2 إلى 10. تم تخمين كفاءة ميرفري للصينية باستخدام معادلة لوبيز و كاستلز (1999) والتي اشارت إلى إن نسبة كفاءة ميرفري إلى الكفاءة النقطية كانت تساوي واحد بسبب إنخفاض قيم عدد بكلت للسائل والتي تراوحت بين 0.07 و 1.5.


Article
Differences Between Sodium Metasilicate and Silicic Acid as Silica Source for Zeolite Y Nanoparticles Synthesis by Sol- Gel Method

Authors: Yousif Jawad --- Adil A. Al-Hemiri عادل احمد عوض
Journal: Iraqi Journal of Chemical and Petroleum Engineering المجلة العراقية للهندسة الكيمياوية وهندسة النفط ISSN: 19974884/E26180707 Year: 2009 Volume: 10 Issue: 4 Pages: 13-17
Publisher: Baghdad University جامعة بغداد

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Abstract

Zeolite Y nanoparticles were synthesized by sal — gel method Different samples using two silica sources were prepared.Sodium metasilicate (Na2Si03) (48% silica) and silicic acid silica (H2SIO3) (75% silica) were employed as sihca source and aluminum nitrate (Al(N03)3.9H20) was the aluminum source with tetrapropylammonium hydroxide(TPA Of- as templating agent.The synthesized samples were characterized by X-ray dW?action, showed the requirement different aging time for complete crystallization to be achieved. Transmission Electronic Microscope (TEM) images, showed the particles were in the same range of 30 — 75 nm PT-JR spectroscopy, showed the synthesized samples having the zeolite Y crystal properties. The initial mixing silica to alumina raao (5i02/A was 10, but, sodium metasilicate sample was of 2.55 final ratio, while silicic acid sample have 18.41 and the surface area as tested by BET was of 55587 m2/g from sodium metasilicate sample and 276.3 m2/gfrom silicic acid sample.


Article
Prediction of the Point Efficiency of Sieve Tray Using Artificial Neural Network

Authors: Firas N. Hassan --- Adil. A. Al-Hemiri عادل احمد عوض
Journal: Iraqi Journal of Chemical and Petroleum Engineering المجلة العراقية للهندسة الكيمياوية وهندسة النفط ISSN: 19974884/E26180707 Year: 2009 Volume: 10 Issue: 4 Pages: 57-62
Publisher: Baghdad University جامعة بغداد

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Abstract

An application of neural network technique was introduced in modeling the point efficiency of sieve tray, based on a data bank of around33l data points collected from the open literature.Two models proposed,using back-propagationalgorithm, the first model network consists: volumetric liquid flow rate (QL), F foctor for gas (FS), liquid density (pL),gas density (pg), liquid viscosity (pL), gas viscosity (pg), hole diameter (dH), weir height (hw), pressure (P) and surfacetension between liquid phase and gas phase (o). In the second network, there are six parameters as dimensionless group: Flowfactor (F), Reynolds numberfor liquid (ReL), Reynolds numberfor gas through hole (Reg), ratio of weir height to hole diqmeter (hw/dH), ratio of pressure of process to atmosphere pressure (P/Pa), Weber number (lTe).Statistical analysis showed that the proposed models have an average absolute relative enor (AARE) of 9.3% and standard deviation (SD) of 9.7%forfirst model, AARE of 9.35% and SD of 10.5%for second model and AARE of 9.8%and SD of 7.5%for the third model.


Article
Anodizing of Aluminum-Magnesium Alloy using Chromic Acid Process

Authors: Khalid A. Al-Zameli --- Adil A. Al-Hemiri
Journal: Journal of Engineering مجلة الهندسة ISSN: 17264073 25203339 Year: 2006 Volume: 12 Issue: 1 Pages: 141-149
Publisher: Baghdad University جامعة بغداد

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Abstract

Aluminum-magnesium alloy has been anodized using chromic acid as an electrolyte. The effect of voltage in the range of 15-60V, electrolyte concentration in the range of 20-110 g/l, electrolyte temperature in the range of 30-60 Co and time of exposure in the range 25-8S minutes on the coating weight of the anodic film are studied. The experimental data was fitted in terms of the coating weight and the coefficients of third order polynomial are estimated. Optimum conditions of the studied variables are predicted and found equal to 32V. 85 g/l,50 Co and 70 minutes.

تم انودة سبيكة المنيوم-مغنسيوم باستخدام حامض الكروميك كمحلول الكتروليتي. تم دراسة تأثير كل من الفولتية من 15-60 فولت وتركيز المحلول الالكتروليتي من 20-110غم/لتر ودرجة الحرارة من 30-60 م◦ وزمن تعرض من 25-85 دقيقة على وزن التغطية. تم ملائمة القيم التجريبية بدلالة وزن التغطية حيث تم ايجاد معاملات معادلة من الدرجة الثالثة ومن ثم استخراج القيم المثلى للمتغيرات ووجدت 32 فولت، 85 غم /لتر ،50 م◦ و70 دقيقة.


Article
Computer Aided Design for Spray Driers

Authors: Adil A. Al-Hemiri عادل احمد الحميري --- Saad N. Saleh
Journal: Iraqi Journal of Chemical and Petroleum Engineering المجلة العراقية للهندسة الكيمياوية وهندسة النفط ISSN: 19974884/E26180707 Year: 2007 Volume: 8 Issue: 1 Pages: 27-34
Publisher: Baghdad University جامعة بغداد

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Abstract

The aim of this work is to develop an axi-symmetric two dimensional model based on a coupled simplified Computational Fluid Dynamic (CFD) and Lagrangian method to predict the air flow patterns and drying of particles. Then using this predictive tool to design more efficient spray dryers. The approach to this is to model what particles experience in the drying chamber with respect to air temperature and humidity. These histories can be obtained by combining the particles' trajectories with the air temperature / humidity pattern in the spray dryer. Results are presented and discussed in terms of the air velocity, temperature, and humidity profiles within the chambers and compared for drying of a 42.5% solids solution in a spray chamber 2.22 m in diameter with a cylindrical top section 2.00 m high and a bottom cone section 1.725 m high.


Article
Separation of Hexane-Benzene Mixtures by Emulsion Liquid Membrane.

Authors: Muhammad D. Al Zaidi --- Adil A. Al Hemiri عادل احمد عوض
Journal: Iraqi Journal of Chemical and Petroleum Engineering المجلة العراقية للهندسة الكيمياوية وهندسة النفط ISSN: 19974884/E26180707 Year: 2008 Volume: 9 Issue: 4 Pages: 1-6
Publisher: Baghdad University جامعة بغداد

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Abstract

The effect of operating parameters on the batch scale separation of hydrocarbon mixture (benzene and hexane) usingemulsion liquid membrane technique is reported. Sparkleen detergent was used as surfactant and heavy mineral oil assolvent to receive the permeates.From the experimental results, the parameters that influenced the permeation are, composition of feed, contact timewith solvent, ratio of volume of solvent to volume of hydrocarbon feed, ratio of volume of surfactant solution to volumeof hydrocarbon feed, surfactant concentration, mixing intensity and glycerol as polar additive in the surfactant solutionto eliminate drop breakup.The best conditions for the separation in this study were found to be: composition of feed (mole fraction ofbenzene=0.5245), contact time of 10min. , ratio of volumes of solvent to feed equal 3.5 , ratio of volumes of surfactantsolution to feed of 0.4, surfactant concentration of 1wt%, mixing intensity equal 1000rpm and 70% by weight of polaradditive. These conditions gave a separation factor of (8.0).


Article
Simulation of Wiped Film Evaporator

Authors: Jamal A.L. Al-Ani --- Emad F. Mansour --- Adil A. Al-Hemiri عادل احمد عوض
Journal: Iraqi Journal of Chemical and Petroleum Engineering المجلة العراقية للهندسة الكيمياوية وهندسة النفط ISSN: 19974884/E26180707 Year: 2008 Volume: 9 Issue: 2 Pages: 43-50
Publisher: Baghdad University جامعة بغداد

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Abstract

A mathematical model and associated computer program were developed to simulate the steady state operation of wiped film evaporators for the concentration of glycerol-water solution. In this model, various assumptions were made to facilitate the mathematical model of the wiped film evaporator. The fundamental phenomena described were: sensible heating of the solution and vaporization of water. Physical property data were coded into the computer program, which performs the calculations of this model. Randomly selected experiments were carried out in a small scale wiped film evaporator from ALVAL COMPANY, using different concentrations of the glycerol solution (10, 30 and 50 Wt. %) for different feed rates (30, 50, 80, 100 and 120 l/h) and two values of steam jacket pressure (2 and 4 atm) to compare between experimental and simulation results. The statistical analysis gave correlation coefficient of 0.9972, average absolute error of 2.2527 % and F-test of 0.9639 which showed the high accuracy of the simulation work.


Article
COMPUTATIONAL ANALYSIS OF THE MIXING ZONE IN THE COMBUSTION CHAMBER OF RAMJET

Authors: Sa’ad A. Fa’ek --- Adil A. Al-Hemiri عادل احمد عوض
Journal: Iraqi Journal of Chemical and Petroleum Engineering المجلة العراقية للهندسة الكيمياوية وهندسة النفط ISSN: 19974884/E26180707 Year: 2008 Volume: 9 Issue: 3 Pages: 27-32
Publisher: Baghdad University جامعة بغداد

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Abstract

A theoretical analysis of mixing in the secondary combustion chamber of ramjet is presented. Theoretical investigations were initiated to insight into the flow field of the mixing zone of the ramjet combustor and a computer program to calculate axisymmetric, reacting and inert flow was developed. The mathematical model of the mixing zone of ramjet comprises differential equations for: continuity, momentum, stagnation enthalpy, concentration, turbulence energy and its dissipation rate. The simultaneous solution of these equations by means of a finite-difference solution algorithm yields the values of the variable at all internal grid nodes. The results showed that increasing air mass flow (0.32 to 0.64 kg/s) increases the development of velocity profile due to the high turbulence generated resulting in very fast mixing and homogenous flow. And the occurrence of chemical reaction causes higher local temperature and composition resulting in faster development of the velocity profile

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