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q = 6427 W/m2 - the heat flux through the external surface
rext= 514 °K - the average temperature on the external surface of the kiln
Fig. 5. The temperature field in the new proposed construction of the rotary kiln’s lining q = 2671 W/m2 - the heat flux through the external surface Text= 389 °K - the average temperature on the external surface of the kiln Based on the thermogram can draw conclusions about the new construction of the lining:
1) By creating a layer of basalt fibers on the outer edge of fireclay lining result in lower temperature of 125 °K.
2) The decrease of the heat flux through the new design lining is 2.4 times less than the standard lining.
3) Application of the new liner design reduces fuel consumption, as reduce heat loss to the environment. This helps reduce harmful
emissions.
4) Application of the new design will reduce the share of the lining of heat loss proportional to the decrease of the heat flux.
References
1. Ходоров Е.А. Печи цементной промышленности. Ленинград, , 1968, 432 c.
2. Чудновский А.Ф., Теплофизические характеристики дисперсных материалов./ Физматгиз, М.,1962, с.323.
3. Кривандин В.А. Теплотехника металлургического производства. Т. 1 / А.В. Кривандин, В.А. Арутюнов, В.В. Белоусов. - М.: Изд. МИСиС, 2002. - 608 с.
4. Линер А. Еремин Н.,Линер Ю.,Певзнер И. Производство глинозема / / М.,Металлургия, 1978, 344с.
5. Steffen W. Hydrogen energy from coupled waste gasification and cement production - a thermochemical concept study / W. Steffen, S. Hamel and W. Krumm // International Journal of Hydrogen Energy. - 2006. - Vol. 31. - Issue 12. - P. 1674-1689
6. U. Kaantee, R. Zevenhoven, R. Backman, M. Hupa. Cement manufacturing using alternative fuels and the advantages of process modeling// Fuel Processing Technology №85. 2004 г. P. 293-301
7. Кривандин В.А., Филимонов Ю.П., Теория, конструкции и расчеты металлургических печей. / M.: Металлургия, 479 с.
8. Кутутеладзе С.С. Основы теории теплопередачи, М., Атомиздат, 1990,
416 с.
Шариков Ю.В.1 Титов О.В.2
'Доктор технических наук, профессор; 2кандидат технических наук, ассистент Национальный минерально-сырьевой
университет «Г орный»
МОДЕЛИРОВАНИЕ И УПРАВЛЕНИЕ ПРОЦЕССАМИ ОКИСЛЕНИЯ БИТУМОВ В КОЛОННЫХ ОКИСЛИТЕЛЬНЫХ АППАРАТАХ НЕПРЕРЫВНОГО ДЕЙСТВИЯ
Аннотация
Данная работа посвящена исследованию влияния конструктивных особенностей аппарата окисления на качество битумов. Разработана математическая модель процесса окисления битума. На основе предложенной математической модели было проведено моделирование процессов окисления в секционированном аппарате, исследовано влияния числа ячеек, распределения температур по ячейкам и расхода воздуха в различные ячейки.
Ключевые слова: математическая модель; окисление; битум; колонный аппарат.
Sharikov Y.V.1, Titov O.V.2
'Doctor, professor; 2PhD in technical, assistant National mineral resources university (University of mines)
SIMULATION AND CONTROL OF BITUMEN’S OXIDATION PROCESSES IN BUBBLE TOWERS OF CONTINUOUS
ACTION
Abstract
It has been researched influence of the oxidation unit design features on the process of tars oxidation for the purpose of stable quality bitumen’s production.
The mathematical model of the oxidation of the tars initiated by air has been constructed. The simulation of processes of oxidation in the partitioned device has been spent. It has been researched influences of number of cells, distributions of temperatures on cells and air expense in various cells
Keywords: bitumen; bubble tower; oxidation processes.
It is known that quality of bitumen is influenced by basic three factors: structure of raw materials for oxidation, oxidation conditions of and it’s the choice of equipment, and also structure of commodity bitumen. At present there are various methods of tars oxidation process efficiency increasing, in order to obtain reception bitumen’s, in particular, it is a method of increasing of surface of phases contact of with the development of air devices, use dispersers an air. Optimization of the parameters of technological process and raw materials selection also has positive influence. Further more Application of catalysts of oxidation and oxidizers specially entered into system should be mentioned.
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The given work is devoted to the research of the influence of oxidation device design on quality of bitumen’s. The research has been focused on the studying of sectioning of the device of oxidation on efficiency, process as well as quality of received products.
You can see oxidizing reactors in the figures.
Fig. 1. Diagrams of the oxidizing tower of the various design.; 1-single-section tower, 2- two-section tower, 3- three-section tower. The columned device as an oxidizer can be divided into sections with the help of special bubble-cap tray.
The description of disks is presented below.
1 2 3
Fig. 2. Diagram of work of the bubble-cap tray: 1 — nipple; 2 — hood; 3 — disk of the dish; 4— overflow pipe; 5— exhaust partition. H— height of the fluid level in the downcomer; hCT— height of the glass; hra— Height of the static suction head at liquid plum; 1сл — height
of the downcomer.
The bubble-cap tray is a metal disk having a set of apertures for steam pass. There are boards of the certain height, named glasses fixed around apertures. These boards are fixed to keep the certain liquid level. The glasses are covered by a bubble-cap.
There is a gap for the pass of the stream coming from lower disk between top part of the glass and the bubble-cap.
The bubble-caps are plunged into the liquid at work and consequently the hydraulic gate is formed, where steams are passed through.
The liquid level at the disks is supported by drain partitions (tank port). Their bottom part reaches the following disk. The liquid surplus goes down a long tank ports on an under laying disk. The position of bubble-caps may be regulated, changing the gap size between a bubble-cap and the top part of the glass. It is very important, that disks are placed horizontally in the oxidizing tower; further more and all bubble-caps are equally plunged in the liquid at the disk. On the contrary the liquid layer will be thinner in any part of the disk. And as a result more liquid volume can go through this part of the disk.
Consequently the other bubble-caps on the rest of the disk stop working.
The analysis of processes of mass-heat-exchange has allowed studying the influence of various conditions of process carrying out on the characteristics of the end-product. Besides, it has allowed studying internal characteristics of the process. Further the hydrodynamic model of process, as a basis of the mathematical description has been studied. Then kinetics of the oxidation process has been made.
In the second task the influence of oxidation conditions and sectioning of the working zone of the device on the oxygen conversion and the quality of end product has been investigated.
The simulation of oxidation processes has been made with the help of computer program ReactOp Cascade 3.20. Parameters have been calculated.
Besides the conclusions of the research results have been made based on the parameters.
As a result of the work the mathematical model of the oxidation of the tars initiated by air, adequately describing all set of experimentally received dependences has been constructed.
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On the basis of the offered mathematical model simulation of oxidation processes in the partitioned device has been made, the influences of the cells number, temperature distributions and air expense in various cells have been tested.
You can see curves charts in the figures.
Fig.3. Kinetic speed performance curve of the changing of the content pyrobitumens at the tars oxidation in the oxidizing tower of a various design; curve №1- single-section tower, №2- two-section tower, №3- three-section tower.
Fig. 4. Kinetic performance curve of the changing of the content tars at the tars oxidation in the oxidizing tower of a various design; curve №1- single-section tower, №2- two-section tower, №3- three-section tower.
Fig. 5. Kinetic speed performance curve of the oxygen uptake at the tars oxidation in the oxidizing tower of a various design; curve №1- single-section tower, №2- two-section tower, №3- three-section tower.
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Fig.6. Kinetic speed performance curve of the changing of the content pyrobitumens at the tars oxidation in the three-section tower; curve №1- temperature 623К, №2- 523К, №3- 423К, №4- 398К.
As a result of our calculations and on the basic of the results of simulation it is possible to confirm:
• Temperature is one of the defining factors influencing for rate of the reaction of oxidation of various groups of hydro carbon components of tar (vast quantity of high-molecular products of oxidation pyrobitumens have been obtained during our research).
• The more temperature is the more intensive high molecular components transformation takes place. Besides consolidation reactions.
Hence, the optimum temperature of oxidation of raw materials will define substantially by the quality of the received bitumen.
• What is more air expense strongly influences on the oxidation process. The expense increase on sections positively affects the conversion pirobytumens. It is possible to draw a conclusion on the basis of kinetic curves of oxygen the efficiency of oxygen use is decreasing. It can be explained by the fact that with the increase of oxidation time the viscosity of raw materials increases, the speed of reactions of consolidation with formation pirobytumens from pitches decreases.
It also should be started that idea. Results of simulation of sectioning of hollow towers for the purpose of the processes of tars oxidation intensification are confirmed. Sectioning of columned hollow unit is a perspective direction which can be realized at the current bitumen plants.
References
1.Эрих В. Н., Расина М. Г., Рудин М. Г. Химия и технология нефти и газа. М.:«Химия», 1972.
2.Иванова Л. В., Корнеев М. И., Юзбашев В. Н. Технология переработки нефти и газа. М.: «Химия», 1986.
ХИМИЧЕСКИЕ НАУКИ / CHEMISTRY
Тунгатарова С.А,1, Байжуманова Т.С.2, Жумабек М.3, Касымхан К.4, Комашко Л.В5.
'Доктор химических наук, 2кандидат химических наук, 3магистр химии, 4бакалавр химии, 5научный сотрудник, Институт органического катализа и электрохимии им. Д.В. Сокольского СТАБИЛЬНОСТЬ PT-RU КАТАЛИЗАТОРА В СЕЛЕКТИВНОМ ОКИСЛЕНИИ МЕТАНА В СИНТЕЗ-ГАЗ
Аннотация
Представлены результаты исследования стабильности разработанного мелкодисперсного оптимального состава Pt-Ru = 1 : 1 (Pt : Ru = 0,7 : 0,3, ат.%) катализатора в реакции селективного каталитического окисления и парокислородной конверсии метана в синтез-газ при миллисекундных временах контакта.
Ключевые слова: катализатор, синтез-газ.
Tungatarova S.A.1, Baizhumanova T.S.2, Zhumabek М.3, Каssymkhan К.4, ^mashko L.V.5
'Doctor of Science, 2Ph.d., 3Master of Chemistry, 4BSc Chemistry, ^Research Fellow, D.V. Sokolsky Institute of Organic Catalysis and
Electrochemistry
STABILITY OF THE Pt-Ru CATALYSTS IN SELECTIVE OXIDATION OF METHANE INTO SYNTHESIS-GAS
Abstract
The results of stability studies of optimal particulate developed Pt-Ru = 1: 1 (Pt: Ru = 0,7: 0,3, at.%) Of the catalyst in the reaction SCO (selective catalytic oxidation) and steam-oxygen conversion of methane to synthesis gas at millisecond contact times.
Keywords: catalyst, synthesis-gas.
Синтез-газ является важным исходным сырьем для производства многочисленных химических продуктов. В зависимости от соотношения водорода и оксида углерода в синтез-газе он используется для получения жидких углеводородов или кислородсодержащих соединений, включая метанол, уксусную кислоту, формальдегид или диметловый эфир [1]. Реакция СКО метана, дающая в продуктах мольное соотношение Н2/СО = 2,0, могла бы стать реакцией, альтернативной реакции парового реформинга метана для производства синтез-газа:
В литературе имеются сведения о применении катализатора, содержащего биметаллическую 1вес.%И-Ен активную фазу с соотношением металлов 50/50, нанесенную на носитель СеОг^ЮгА^Оз с содержанием элементов 50вес.%Pt/Al2Oз+25вес.%Ru/Al2Oз+25вес.%Ru/СеО2-ZrО2 [2] Перед процессом СКО катализатор восстанавливают водородом, постепенно повышая температуру со скоростью 15оС/мин до 1173К в потоке аргона. Исследования процесса СКО проводили в реакторе проточного типа при объемных скоростях 26000, 53000 и 93000 ч-1 и соотношениях (об. %) СН4/О2/М2=3,4/1,7/94,9 %.
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