One of the major problems in industry are new welding trainees cost, it drains the budget of many companies, particularly in industrialized countries, through raw material costs for preparation, welding wires, electric and fumes in addition to time spent. Recently a new technique was appeared; it is called virtual welding training system (VWTS) to reduce the training cost. In the present work a VWTS technique was built, a simulation of electrode motion is upgraded by using LVDT to represent the welding arc length while a DC motor with gearbox connect to the steel rode is used to represent welding electrode consumption. A 2D graphs with touch screen monitor are used to represent welding process. All sensors were calibrated to generate a VWTS. Accepted results obtained in training new welding trainees in the shielded metal arc welding (SMAW) training.

Virtual welding --- electrode simulator --- SMAW --- LVDT --- VWTS

The prediction of the concentration fields of pollutants released to the atmosphere is a key factor in assessing possible environmental damages caused by industrial emissions. To solve the concentration equation for gaseous or particulate effluents it is necessary to know as accurately as possible the velocity field and turbulence intensities at the atmospheric boundary layer in the region of interest. A two dimensional mathematical model based on the equations of fluid mechanics along with a modified non-isotropic k-ε turbulence model are employed to calculate the flow and dispersion at the atmospheric micro scale (distances of the order of kilometers).Results of investigation are obtained by using the finite volume method (FVM) to solve the average Navier Stock equations coupling with turbulent k- ε model. The calculation was carried out for plume flow from the industrial chimney with different plume velocities, wind velocities and heights of stack. The equations of model are solved with SIMPLE schemes.FLUENT program used to show the results of the plume flow at the variable parameters of wind and plume velocities and heights of stack, the code is applied to simulate several cases of flow and dispersion. Comparisons against experimental results show that the non-isotropic turbulence model has better ability to foresee the plume dispersion than the standard k- ε, in which the non-isotropic character of turbulence is relevant. The computational results show that the plume path and concentrations are correctly predicted by the numerical model

Chimney --- Navier-Stock equation --- k-ε model --- Emission of pollutant --- FLUENT codeIntroduction

Oxides of nitrogen (NO + NO2 , (NOx)) are emitted from refineries, not only contribute to the production of photochemical smog at ground level but also cause damage to plant life and add to the problem of acid rain. The small amounts of prompt NO produced in the furnace chambers and oil refineries because the formation of NOx can be attributed to four distinct chemical kinetic processes: thermal NOx formation, prompt NOx formation, fuel NOx formation, and intermediate N2O. In this paper, the portions of pollutants that resulted in fuel burning (liquid or gas) in oil and gas refinery were studied by modeling of emitted gases in furnace chamber. The case study at Nassiriya power plant with different loads (70 – 210) MW was studied. The method of finite volume was studied to predict the pollutant portions by using FLUENT computer code (FLUENT is one of largest codes of computer programs which solve thousands of flow and combustion cases. The case study was drawn graphically then imported to solve by FLUENT). These types of pollution species are NOx and SOx as the important air pollutant influenced the human health. The numerical analysis in calculating the pollutants of chamber gave the findings of crude oil emission in combustion is higher than that at using gaseous fuel. So, the methods of decreasing NOx and SOx pollution by water injection and exhaust gas recirculation are used in refinery operation were presented

تنبعث أكاسيد النيتروجين (NO + NO2) من المصافي، وتساهم ليس فقط في إنتاج الضباب الدخاني الكيميائي الضوئي على مستوى سطح الأرض ولكن أيضا تسبب ضررا على الحياة النباتية وتضاف إلى مشكلة الأمطار الحمضية. يعزى تكون كميات صغيرة من أكاسيد النيتروجين في غرف الفرن ومصافي النفط إلى أربعة عمليات حركية كيميائية منفصلة هي: تكون أكاسيد النيتروجين الحرارية، تكون أكاسيد النيتروجين الفورية ، تكون أكاسيد النيتروجين من الوقود، و(N2O) الوسطية. في هذا البحث، تمت دراسة مكونات الملوثات التي نتجت عن حرق الوقود السائل أو الغاز في مصفاة النفط والغاز والتي درست بنمذجة الغازات المنبعثة في غرفة الفرن. وقد درست حالة الدراسة في محطة توليد كهرباء الناصرية بأحمال مختلفة (70-210 MW). ودرست الحالة بطريقة الحجم المحدد للتنبؤ بنسب الملوثات باستخدام برنامج الكمبيوتر (FLUENT) والذي هو واحد من أكبر البرامج لحل الاف الحالات للجريان والاحتراق. اعتمدت دراسة الحالة بيانيا ثم استيرادها للحل بواسطة(FLUENT) هذه الأنواع من عناصر التلوث هي أكاسيد النيتروجين وأكاسيد الكبريت هي من اهم ملوثات الهواء التي تؤثر على صحة الإنسان. أعطى التحليل العددي في حساب الملوثات في غرفة الاحتراق نتائج لانبعاثات احتراق النفط الخام أعلى من ذلك في استخدام الوقود الغازي. لذلك، قدمت الدراسة استخدام أساليب خفض أكاسيد النيتروجين وأكاسيد الكبريت الملوثة عن طريق حقن المياه وإعادة تدوير غاز العادم عند تشغيل المصفى.

Pollutant --- Pollution --- Nox --- Sox --- Combustion --- ملوثات، تلوث، اكاسيد النيتروجين، اكاسيد الكبريت، احتراق