121 |
Fluidní kotel CFB na spalování dřevní biomasy o parametrech páry 150 t/h; 9,3 MPa; 530 °C / Fluid boiler CFB for wood biomass combustion, setam paramters 150 t/h; 9,3 MPa; 530 °CMartinek, Jan January 2015 (has links)
This diploma thesis deals with the control calculation of fluid biomass boilers with circulating fluidized bed. The introduction briefly introduced fluidized bed boilers and explained what biomass is. Furthermore there is a stoichiometric calculation of combustion. The calculation of the losses and the efficiency of the boiler is following. Desulphurization is calculated briefly. The main part is devoted to the design and calculation of individual heat exchanging surfaces: superheater P1, superheaters 2 and 3, the wall superheater, the return chamber, hanging tubes, economizer and air heater. At the end is calculated total tolerance boiler. Work is completed with a diagram of temperature of working media and combustion.
|
122 |
Snížení emisí SO2 ve spalinách z fluidního kotle / Reducing emissions of SO2 in the flue gas from the fluidized bed boilerTesař, Jan January 2016 (has links)
Aim of this thesis is to design a technology of a flue gas desulphurization of fluidized bed boiler. Currently, the state of technology is not able to provide flue gas desulphurisation to required level. For this reason it is necessary to build additional device for the desulphurisation. Theoretical part of the thesis deals with the emission limits of sulphur dioxide, available methods of desulphurization and sorbents suitable for the desulfurization. In practical part conditioned dry sorption method is chosen for the specified source, technological and structural design for suggested desulphurization technology including design of all device is proposed. The thesis also includes a technology design and a 3D model.
|
123 |
NUMERICAL SIMULATION OF STEEL DESULFURIZATION PROCESS IN THE GAS-STIRRED LADLECongshan Mao (8262324) 05 May 2022 (has links)
<p> </p>
<p>A three-dimensional isothermal multiphase flow transient CFD model simulation of the comprehensive chemical processes, including desulfurization and reoxidation in a gas-stirred ladle during the secondary refinement process, has been investigated. The multiphase interactions and turbulence flow among steel, slag, and gas inside a ladle are simulated based VOF multiphase model and discrete model (DPM) in Fluent commercial software. A widely used theory describing the desulfurization and reoxidation processes, (Al2O3) -[O] equilibrium theory, is introduced into the model. The compositions of both steel and slag are monitored, and the mass fractions of each species in steel and slag are compared with the industrial data. There are two main stages for this study.</p>
<p>In the first stage, the CFD model of an 80-ton ladle is developed to simulate both the flow field and reaction rates based on literature work. Then the predicated species contents are validated with industrial measurement, which proves the accuracy of the CFD model.</p>
<p>The validated CFD model is applied to a Nucor Decatur two plugs bottom injection ladle in the second stage. There are two different plug separation angle scenarios: 90° and 180°, investigated in this part. Three argon gas flow rate combinations ((5/5 SCFM, 5/20 SCFM, and 20/20 SCFM) were employed. The slag eye size was validated with plant measurement. The results show that the desulfurization rate and reoxidation rate are promoted with a higher argon injection rate. When the argon injection rate is fixed, a larger separation angle improves the reaction rates.</p>
|
124 |
Molecular Modeling of Ionic Liquids for Potential Applications in the Desulfurization of Diesel FuelCaudle, Miranda 10 December 2018 (has links)
No description available.
|
125 |
Predictive Modeling Of Sulfide Removal In Tray AeratorsFaborode, Jumoke O. 01 January 2010 (has links)
Hydrogen sulfide is commonly found in many Florida potable groundwater supplies. Removing sulfur species, particularly hydrogen sulfide is important because if left untreated, sulfide can impact finished water quality, corrosivity, create undesirable taste and odor, and oxidize to form visible turbidity and color. This document presents the results of a study designed to investigate the removal efficiencies of a variety of tray aerators in Central Florida in order to develop a predictive mathematical model that could be used to determine tray effectiveness for sulfide removal. A literature review was performed that indicated there was limited information regarding the removal of hydrogen sulfide using conventional tray aerators, and no information regarding the removal of total sulfide from tray aerators. There was significantly more information available in the literature regarding the usefulness of sulfide removal technologies from water supplies. Consequently, the lack of literature regarding sulfide removal using tray aerators suggested that there was a need for additional research focused on sulfide removal from water flowing thru tray aerators. Several water purveyors that relied on tray aerators as a part of their water treatment operations were contacted and requested to participate in the study; three water purveyors agreed to allow the University of Central Florida (UCF) to enter their secured sites to collect samples and conduct this study. The three facilities included the UCF‘s water treatment plant located in Orlando and situated in eastern Orange County, the City of Lake Hamilton‘s water treatment plant located in west-central Polk County, and the Sarasota-Verna water treatment plant located in western Sarasota County. An experimental plan was developed and field sampling protocols were implemented to evaluate sulfide removal in commonly used tray aerators at the three drinking water treatment facilities. Total iv sulfide concentrations passing through the trays were determined in the field at each site using a standard iodometric analytical technique. In addition, other water quality parameters collected included dissolved oxygen, pH, temperature, conductivity, turbidity, alkalinity, hardness, total dissolved solids and total suspended solids; these samples were collected and analyzed either in the field or at the UCF laboratory. A first-order empirical model was developed that predicted sulfide removal in tray aerators. The model‘s constant was evaluated with respect to the water‘s proton concentration [H + ], the tray aerator‘s surface area, and hydraulic flow rate thru the trays. The selected model took the form of Cn=C0 (10-kn ) where Cn is the sulfide remaining after aeration in mg/L, C0 is the sulfide entering the distribution tray in mg/L, n is the number of tray stages in the aerator, and . From the empirical model, it was shown that sulfide removal was negatively impacted as the proton concentration (H+ ) decreased, and flow increased. Conversely, it was observed that increased sulfide removal occurred as the available tray aerator surface area increased. The combined parameters of proton concentration, flow rate, and area were statistically evaluated and used to develop an empirical constant that could be used in a first order model to predict sulfide removal in tray aerators. Using a site-specific derived experimental (empirical) constant, a water purveyor could use the developed model from this work to accurately predict sulfide removal in a tray aerator by simply measuring the total sulfide content in any raw groundwater supply and then providing the desired number of tray stages available for treatment.
|
126 |
Evaluation of the flue gas desulfurization mine seal and sedimentation pond at Broken Aro Mine Reclamation Site located in Coshocton County, OhioThomas, Jed H. January 2001 (has links)
No description available.
|
127 |
Regenerable metal oxide Composite particles and their use in novel chemical processesGupta, Puneet 09 August 2006 (has links)
No description available.
|
128 |
A Lysimeter Study of Vadose Zone Porosity and Water Movement in Gypsum Amended SoilsTirado-Corbala, Rebecca 14 December 2010 (has links)
No description available.
|
129 |
[pt] MODELAMENTO DO CONSUMO DE CAL NO PROCESSO DE DESSULFURAÇÃO DE GASES DE COMBUSTÃO DE UMA COQUERIA DO TIPO HEAT RECOVERY USANDO REDES NEURAIS ARTIFICIAIS / [en] MODELING LIME CONSUMPTION OF A DESULFURIZATION PROCESS FROM GASES OF A HEAT RECOVERY COKE PRODUCTION PLANT USING NEURAL NETWORK DEVELOPMENTFREDERICO MADUREIRA MATOS ALMEIDA 26 February 2021 (has links)
[pt] A produção de coque metalúrgico em plantas do tipo heat recovery convertem todo o calor gerado da combustão de gases destilados durante a coqueificação em vapor e eletricidade, portanto eliminando a necessidade de processamento de sub-produtos químicos e rejeitos perigosos. Os gases, após a etapa de inertização no interior dos fornos, são direcionados à planta de dessulfuração denominada flue gas dessulfurization que utiliza lama de cal para abatimento de compostos SOx (SO2 e SO3) e filtros de mangas para remoção do resíduo gerado, cinzas de cal, precedente ao descarte para a atmosfera. Em virtude do alto custo da cal torna-se importante modelar o processo e avaliar quais são as principais variáveis que impactam no re-sultado, logo permitindo atuação no processo para torna-lo mais competitivo e am-bientalmente sustentável. A proposta deste trabalho foi elaborar um modelo matemático usando redes neurais artificiais para determinar as principais variáveis que impactam o consumo específico de cal no processo. A literatura existente revela que os principais parâmetros que impactam a eficiência de remoção de enxofre, logo a redução de consumo específico de cal, são temperatura de aproximação e relação Ca/S no processo. Este estudo indicou que o consumo está relacionado, principal-mente, aos parâmetros de temperatura dos gases na entrada e saída do SDA, além de concentração de oxigênio na chaminé principal e densidade da lama de cal utilizada de acordo com a análise de sensibilidade de rede neural feedfoward backpropagation com arquitetura MLP 14-19-2 e função de transferência tangente hiperbólica na ca-mada intermediária e logística na camada de saída. A avaliação reforçou o efeito do aumento da temperatura de saída dos gases no consumo específico de cal conforme literatura e adicionou parâmetros relevantes: temperatura de entrada dos gases, con-centração de O2(g) na chaminé e densidade da lama. / [en] The production of metallurgical coke in heat recovery coke production plants converts all heat generated from the combustion of distilled gases during coking pro-duction to steam and electricity, thus eliminating the need of processing hazardous by-products chemical substances. The gases, after inertization inside the ovens, are directed to the desulphurization plant called flue gas desulphurization (FGD) which uses lime slurry to remove SOx compounds (SO2 and SO3) and bag filters to remove the generated residue, lime ash. Due to the high cost of lime, it is important to model the process and evaluate which are the main variables that affects its result, thus allowing action in the process to make it more competitive and environmentally sus-tainable. The purpose of this work was to develop a mathematical model using arti-ficial neural networks to determine the main variables that affect lime consumption in the desulphurization process. Literature reveals that the main parameters that in-fluence sulfur removal efficiency, thus reducing specific lime consumption, are ap-proach to adiabatic saturation temperature and Ca/S ratio in the process. This study indicated that consumption is mainly related to the inlet and outlet SDA gas temper-atures, oxygen concentration in stack and lime slurry density according to the feed-foward backpropagation neural network sensitivity analysis. MLP 14-19-2 and hy-perbolic tangent transfer function in the intermediate layer and logistics in the output layer. Thus, the evaluation reinforced the effect of the increase of the gas outlet tem-perature on the specific lime consumption according to the literature, but also added new parameters: gas inlet temperature, O2 (g) concentration in the outlet of stack and lime slurry density.
|
130 |
Scrubbing of sulfur dioxide from secondary process gases in a copper smelter / Skrubbning av svaveldioxid från sekundära processgaser vid ett kopparsmältverkOkolo, Obiora January 2021 (has links)
Processindustrin är den största källan för utsläpp av svaveldioxid (SO2) i Sverige, vilket även inkluderar ickejärnmetallindustrin. Kopparsmältverket Boliden Rönnskär har ett miljötillstånd som tillåter SO2-utsläpp på maximalt 3500 ton/år, en gräns som Rönnskär har legat nära under de senaste åren. För att minska svaveldioxidutsläppen på Rönnskär så har våtskrubbning (tillsammans med ett bagfilter för stoftrening) föreslagits som en metod för att rena de SO2-bärande och intermittenta tappgaserna från flashugnen. För att göra ett optimalt val av våtskrubberteknik för ändamålet, undersöktes, utvärderas och jämfördes våtskrubbningstekniker baserade på de följande kemikalierna i denna rapport: lut, soda, peroxid, kalk and zinkoxid. Mätningar gjordes också på sekundärhuvsgaserna från konvertrarna, som också kan användas i skrubbern då flashugnens tappgaser har ett fluktuerande flöde. Vidare gjordes tester på olika processvatten på Rönnskär, som skulle kunna återanvändas i skrubbern. Skrubbrarna utvärderades sedan baserat på indata och olika systemkrav med hjälp av simulerings och designprogram samt teoretiska beräkningar. Resultaten visade att det är rimligt att rena sekundärhuvsgaser i skrubbern, då de innehöll ca 280 ton SO2/år. Detta kan jämföras med flashugnens tappgaser som innehöll ca 445 ton SO2/år. Bland skrubbrarna, så utvecklade peroxidskrubbern sig till att vara den mest attraktiva tekniken på grund av dess relativt låga livscykelkostnader och dess lämplighet med både lakverket och flashkyltornsprocessvattnet. De andra teknikerna med packade torn, lut och sodaskrubbern, hade högst livscykelkostnader, huvudsakligen på grund av deras höga kemikaliekostnader. Sodaskrubbern, som var den billigare av de två natriumbaserade skrubbarna, skulle kunna vara lämplig ändå på grund av teknikens enkelhet. De öppna tornen hade lägre livscykelkostnader jämfört med de packade tornen. Dock så hade kalkskrubbern flera nackdelar som gör att den inte är ett lämpligt alternativ. Zinkoxidskrubbning har i sin tur inte studerats tillräckligt och är en relativt oprövad teknik, men den bör studeras vidare då den skulle kunna integreras med zinksmältningsprocessen på Rönnskär. Användningen av processvatten i skrubbern skulle leda till en nettominskning av processvatten till reningsverket. Det skulle även leda till minskade reagentkostnader ifall en stripper installeras för att ta bort SO2 från processvattnen innan de går in i skrubbern. / The processing industry is the largest source of sulfur dioxide (SO2) emissions in Sweden, which includes the nonferrous metals industry. The copper smelter Boliden Rönnskär has an environmental permit to emit a maximum of 3500 tonnes of SO2/year, a limit that the smelter has been close to in recent years. To reduce the SO2 emissions at Rönnskär, wet scrubbing (together with a bag filter for dust cleaning) has been proposed as a method for cleaning the SO2-bearing, intermittent tapping gases from the flash furnace. To find the optimal wet scrubbing technique for the purpose, wet scrubbing techniques based on the following reagents were investigated, evaluated and compared in this report: caustic soda, soda ash, peroxide, lime and zinc oxide. Measurements were also done on the secondary hood gases from the converters, which could make use of the remaining capacity in the scrubber. Further, tests were conducted on various process waters from other processes at Rönnskär, waters that could be reused in the scrubber. The scrubber techniques were then evaluated based on the input data and system requirements using simulation and design software as well as theoretical calculations. The results suggested that it is reasonable to clean secondary hood gases in the scrubber, as they contained approximately 280 tonnes of SO2/year. This could be compared to the flash tapping gases that contained approximately 445 tonnes of SO2/year. Among the scrubbers, the peroxide scrubber evolved as the most attractive technique due to its relatively low life cycle cost and due to its suitability with the leaching plant and the flash cooling tower process water. The other packed tower techniques, caustic soda and soda ash had the highest life cycle costs, mainly due to their high reagent costs. The soda ash scrubber, which was the cheaper of the two sodium-based scrubbers, could still be a suitable alternative due to its simplicity. The open spray towers had lower life cycle costs than the packed towers. However, the lime scrubber had several disadvantages that makes it an unsuitable alternative. In turn, the zinc oxide scrubber is a relatively underresearched and unproven technique, but should still be studied further as it could be integrated with the zinc smelting process at Rönnskär. The use of process waters in the scrubber would lead to a net reduction of process water to the process water treatment plant and would lead to reduced reagent costs if a stripper is installed to remove the SO2 from the process waters before entering the scrubber.
|
Page generated in 0.508 seconds