Prevention of Nozzle Clogging in Continuous Casting of Steel

Prevention of Nozzle Clogging in Continuous Casting of Steel Prevention Of Nozzle Clogging In The Continuous Casting Of Steel There have been four documented causes for nozzle clogging in continuous casting steels; build up de-oxidations such as Al2O3 (1), solid steel build up, buildup of complex oxides such as spinels, and the buildup of reaction products such as CaS (4). While some causes are more detrimental than others, all are a problem. Different steels will yield a different potential nozzle clogging cause (3), for example, a re-sulfurized free machining steel is going to have much more of an issue with the formation of calcium sulfides than spinels. No matter what cause is all nozzle clogging can be detrimental to a continuous casting process. Looking at Figure 1, it is easy to see how the deposit of clogging material on the side walls of the nozzle can cause irregular flow from the tundish into the mold. Irregular flow through a tundish nozzle enhances the probability of generating a number of quality defects such as re-oxidation of the steel and slag entrapment (4). Nozzle clogging also affects pr oductivity in that less steel is able to be cast because of the blockage in the nozzle. In simple business terms, less steel equals less profit. Another thing to consider is the life of the tundish is often limited to the life of the nozzle due to clogging. If nozzle clogging can be controlled enough to extend the nozzle life even one or two heats longer, that results in substantial process cost savings. The most effective way to prevent, or at least lessen, nozzle clogging in the continuous casting of steels is to modify the inclusions in the steel to a liquid rather than a solid at steel casting temperatures (2). This is typically done by the addition of calcium to the steel at the end of the steel refining process. Looking at Figure 2, a pure Al2O3 inclusions liquidus temperature is considerably higher than that of steel casting temperatures, and that by adding the right amount of calcium to the inclusions in the steel the inclusions liquidus temperature can potentially be lowered to below steel casting temperatures (12CaO.7Al2O3). Calcium is typically added to the melt one of three ways; by CaSi powder, CaSi wire, or calcium injection with argon. CaSi powder has the poorest recovery because calciums vapor temperature is lower than steel making temperatures (5). Therefore by simply throwing calcium powder on top of the melt, the majority of the calcium will vaporize into a gas and leave the system without being absorbed into the steel. Figure 3 shows the vapor temperature for calcium related to depth into the steel melt and we can see that the deeper into the melt the calcium is able to get (i.e. the greater the pressure) the higher the vapor temperature is for calcium (5). This is the basis by which CaSi wire is used. CaSi wire is a steel wire shell packed with calcium as the core. As the wire is injected into the melt the calcium is protected by the steel shell from melting and not exposed to the high melt temperatures until deep enough into the melt to provide enough pressure to avoid the calcium from vapori zing. Calcium injection uses this same principle by sticking a lance into the melt deep enough to avoid vaporization and blows calcium into the melt by the use of inert argon. Its one thing to make inclusions liquid and its a completely different challenge to keep it liquid throughout the entire casting process. This is often the difficult aspect of nozzle clogging prevention given that all of your incluions modification control is performed at the LMF or degasser and not at the caster. One thing many steel producers will try to do is reduce the number of incluions present in the steel during the casting process (2). The easiest thing to do in lowering the number onf inclusions in the steel is to increase ths size of the inlucions. By Stokes law, larger inclusions will have a greater upward velocity out of the steel and into the slag thus not being cast through the nozzle. Another practice steel producers use to reduce inclusionon counts in their steel is to have proper geometry in the tundish as the caster. By adding tundish components such as dams and weirs (shown in Figure 4) inclusion flow can be directed to give optimum exposure to the slag(4). Weirs a used to direct steel flow down where as dams are to direct flow upwards. By having two sets of weir-dam combinations between the ladle shroud and nozzle, the inclusions in the steel are exposed to the tundish slag all while maintaining minimum turbulance (5). Unfortunatily not all inclusions in the steel can be removed and therefore the remaining inclusions must remain liquid through the nozzle to prevent clogging. To achieve this it is curtial that the steel is protected from re-oxidation from atmospheric oxygen (2). To ensure this many tools are used. Starting from the ladle, a ladle shroud is used from the ladle to tundish in order to funnel the liquid steel from the ladle to under the slag layer in the tudish (Figure 4). An impact pad is often used as shown in Figure 4, to reduce the turbulance in the tundish (5). Increased turbulance can disrupt the slag surface in the tundish as expose the liquid steel to the amtosphere causing re-oxidation and possibily slag entrapment. To help prevent steel -slag interaction,baffles are often used (Figure 5) which slows down steel flow but also allows steel to flow through the holes. In order to prevent the steel exposed to the surface from re-oxidizing tundish fluxes are used to act as a protecti nve barrier between the steel and atmopshere as shown in Figure 6 (2). Tundish refactories must also be considered to ensure no or very little reaction occures between the steel and refactory occurs (2). If it were to occur and solid inclusions percipitate in the steel, all the effort put forth into the steel up until the point could be usless. Once the steel is secure in the tundish one more step is required and that is to get the steel through the nozzle and into the mold. Just as in the tundish, re-oxidation of the steel and any negative reaction between the nozzle refractory and steel must be avoided. To ensure this, typically submerged entry nozzles or submerged entry shrouds are used as the nozzle which will provide a barrier between the steel and atmosphere all the way into the mold. Typically made of alumina graphite, the added graphite prevents wetting of the inclusions onto the nozzle walls (4). Argon purging in various parts of the side walls of the nozzle are also often used to separate any would be oxygen from the steel. In conclusion, preventing nozzle clogging is not successfully completed by one simple action but rather many actions working together: inclusion count reduction, inclusion modification by the use of calcium, protecting from re-oxidation of the steel, proper tundish geometry, and proper tundish and nozzle refractories (2). While the concept of making only liquid inclusions appears simple in application, it can be rather difficult to maintain these liquid inclusions throughout the entire casting process. Sources Cited 1. Zhang, Lifeng; Thomas, Brian; Inclusions in Continuous Casting of Steel. Nationals Steelmaking Symposium. Mich, Mexico. November 2003. page 138-183. 2. Alekseenko, A.A. Problems of Nozzle Clogging during Continous casting of an Aluminum-Killed Low-Carbon Low-Silicon Steel. Russian Metallurgy, Vol. 2007. page 634-637. 3. Girase, N.U. Development of indices of quantification of nozzle clogging dujring continuous slab casting. Iron and Steelmaking. Vol. 34; No. 6. 2007. page 506-512. 4. Zhang, Lifeng, Wand, Yufeng, and Zuo, Xianjmun. Flow Transport and Inclusion Motion in Steel Continuous-Casting Mold under Submerged Entry Nozzle Clogging Condition. Metallurgical and Materials Transaction. Vol. 39B. August 2008. page 534-550 5. The Making, Shaping and Treating of Steel, 11th Edition Casting Volume; AISE Steel Foundation. Pittsburg, PA. Copy Right 2003

Steinbeck presents Crooks

Steinbeck presents Crooks as practical and intelligent. This is shown in chapter in the passage â€Å"rubber boots† â€Å"alarm clock† and the â€Å"California Civil Code† book. The books show he reads and cares about his Rights. It also shows that he is practical and active with his alarm clock. It can alternatively mean that he has to be Intelligent to protect himself from getting beaten by the boss If he is late to which he needs to be protecting himself from horse manure.Also with the Californian civil code to be mauled† suggests he attacked the book with anger which could show a bitter hatred the way that people like him are treated Ilke outsiders causes him to lament his loneliness even in his home state. Steinbeck also presents Crooks as permanent and doesnt move around with evidence supporting this Is, â€Å"battered magazines and a few dirty books on a special shelf over his bunk. It show how he gets beaten down by loneliness and prejudicial treat ment of that he Is the only black man on the ranch. The word â€Å"special shelf† suggests the organisation In his home showing that he Ilkes o be stationary and kept whereas it could also mean he has to stay there by the boss and also live alone rather than mixing with white people so Crooks has to live alone and makes full use of living in the barn.B) His character shows us how coloured people were treated in the 1930's. It tells us that they were treated as second-class citizens and weren't worthy to share anything with non-coloured people, we know this due to Crook's having â€Å"his bunk in the harness room†, I think that it is because his boss doesn't think it's right for Crook's to share a bunkhouse with the other men n the ranch, so Crook's is forced to sleep in the barn.Shows how everyone targeted him as inferior because of the colour of the skin. The separation of his bunk implies that because of his skin colour no one wants to sleep in the same room as him a s they think that Crooks isnt worthy of living with them and so they show their racial hatred towards him by their abuse in calling him a â€Å"Nigger†. Due to this, Crooks could turn to books for company which are the only thing that does not consider him as an outcast.

The Basic Facts of Native American Argumentative Essay Topics

The Basic Facts of Native American Argumentative Essay Topics If You Read Nothing Else Today, Read This Report on Native American Argumentative Essay Topics Writing a college argumentative research paper isn't as simple as it might seem at first. You may also choose any latest research work that's somewhat controversial to allure the readers to compose argumentative essay. If when you are preparing a report you merely analyze specific literature, the essay demands an excellent penetration into the issue. Argumentative research paper topics are a great deal much easier to find than to produce. The Appeal of Native American Argumentative Essay Topics A great communication essay must also have the role of supplying information whenever required. If you're searching for a special offer, you should try different procedures. Our customer support will gladly tell you whether there are any special offers at the present time, along with make sure you are getting the very best service our business can deliver. Another vital element is the option of communication topics or media topics. Ideas, Formulas and Shortcuts for Native American Argumentative Essay Topics Child labour includes working children that are below a particular minimum age. Relevant Topics that are related to your society will engage the reader in the very best possible method. F. Bacon The main goal of the capital isn't to get as much money as possible, yet to guarantee that money results in a better life. Unique Purposes of Education There are unique purposes for gaining education like education will help to sustain an individual's social and financial life. Native American Argumentative Essay Topics America is among the oldest nation in the planet. Native American tribes have continued to discover methods to carry on the rich culture which has been passed down through generations. They live in different environments. Occasionally, selecting a great argumentative essay topics will be quite tough. In any event, your essay is going to have the identical standard format and structure. An argumentative essay requires you to choose a topic and have a position on it. Persuasive or argumentative essays are supposed to convince the audience of a person's viewpoint about a specific topic. There are invariably a wide variety of opinions on the topic of technology, and here are our favourite things to consider on the subject. You're able to support a specific idea when criticizing different facets but let the reader decide. You are able to provoke your audience to take part in a specific action that is essential to deal with the issue or issue discussed in your essay. If you select the incorrect subject, you might get stuck with your writing and have a tough time moving forward. Sum up the primary points and main arguments that you're going to support or refute. It is possible to also restate the ideas which you've discussed in the body paragraphs in order to make your point valid. A lot rides on the kind of topic you're trying to find. There's always time to return and fix sentences to be able to bring a mature, astute voice to your essay. What is Actually Happening with Native American Argumentative Essay Topics You will need to pinpoint what you need to write in your essay. You're able to buy argumentative essay from a specialist writer. Writing argumentative essay is a complicated endeavor, as it requires the presence of many skills at the exact same time. The greatest argumentative essay writing service on the web is a business that supplies good quality and reasonably priced help on argumentative essay and argumentative essay topics. The most important idea of your entire essay is going to be your thesis statement. Most of the folks have a tendency to run away from politics and thus the politics essays also, therefore it is quite important to grab the eye of the readers till the conclusion of the essay and that would be much difficult I know. In this kind of situation, it's more convenient to locate ready-made essays and use them as an example. When it has to do with writing an argumentative essay, the main matter to do is to select a topic and an argument you can really get behind.

The Movie The Rain Man With Having Autism - 866 Words

Raymond was diagnosed in the movie the Rain Man with having autism. The autism symptoms disorder had several of Raymond’s characteristics, such impairment in social interaction, and multiple nonverbal behaviors. In this moment the Medical Model applies in Raymond case, when Raymond as a patient and needed a specialist for his psychological, behavioral, or cognitive disabilities. (Cole). Raymond could not look at people eyes, and most of the times slouched down spoken to keeping on a conversation. He refuse any kind the touch or even any fast anticipation in his directions. Raymond did not like when Charlie tried to hug him, the action was accept even when Charlie tried to explain. Raymond proves to have a personality of his own, that most of the time irritates Charlie. In this time the Client Centered Model when the client with your disability and barriers try to have participation on the life (Cole). During the conversation Charlie was asked Raymond a question, and he often a nswered with a negative answer. Raymond had hard time to carrying a conversation, sometimes used short answer was his away to put people away from his world. Would never start up a conversation with others or acted like he wanted to be around others, most of the times he was in self word without pay attention in others conversation around. When Raymond meet new people he tensed up and did not want to look, or act like anyone was there or speaking with him. Similarly situation made Raymond nervous, likeShow MoreRelatedAutism and Rain Man1505 Words   |  7 PagesAutism and Rain Man In the movies things are portrayed in ways that are supposed to make the movie sell, which means that movies are not always accurate. The movie Rain Man was about a man and his brother, who happened to be an autistic savant. In Rain Man Dustin Hoffman played Raymond, who was a high-functioning autistic savant. In the movie Raymond had routines and rituals that he did; and when his routines were interrupted or he was afraid of something he had a temper tantrum where he wouldRead MoreEssay On The Movie Rain Man1315 Words   |  6 Pagespaper will show how in the movie Rain Man, an adult man acts with high functioning autism. How great certain skills are that make him appear as if he has supermen abilities, while also showing the need for adult supervision for other events that unfold in the movie. While sourcing several references what autism is, its characteristics and how to treat it at an early age to get the best functional outcome as an adult. Along with some of dangers that’s face people with autism from the world around themRead MoreHow Communication Is Difficult And Interacting With Others954 Words   |  4 Pagesscale from what we have learned the past few decades a child who is on the s pectrum of Autism may understand the words, but not the music. There is a buzz word that many parents use to describe their child who is not exactly normal functioning. This means that they are behaving differently than their peers of the same age. This term that parents use to describe their child is Autism Spectrum Disorder (ASD). Autism has gained a lot of notoriety in the past decade due to many more prevalent cases throughoutRead MoreReview Of Rain Man By Dustin Hoffman And Tom Cruise s Movie Fog Man1584 Words   |  7 PagesIn Dustin Hoffman and Tom Cruise’s movie Rain man, Dustin portrayed a man called Raymond, and be diagnosed as autism. The movie present his experience with his brother which portrayed by Tom. According to The Diagnostic and Statistical Manual of Mental Disorders (5th ed,; DSM-5; American Psychiatric Association, 2013), Raymond is diagnosed as autism spectrum disorder (ASD). This paper will describe the symptoms on DSM-5 accompany Raymond’s behaviors in the movie. Moreover, biological, psychologicalRead Mo reAnalysis Of The Movie Rain Man Essay1402 Words   |  6 PagesSummary: In the film entitled Rain Man, a young, egocentric man by the name of Charlie Babbitt takes on the role of a struggling car salesman. While on his way to a small get away with his companion, Susanna, he receives a call that his father has passed away. During the time of the funeral, Charlie reviews his father’s will and learns that he was left a car and his father’s rose bushes. He also is informed that the amount of three million dollars was left to a man named Raymond. In hopes of receivingRead More High-Functioning Autism through Rain Man Essay4135 Words   |  17 PagesHigh-Functioning Autism through Rain Man A man and his brother walk down the terminal in an airport. They engage in a heated argument over whether they should board an airplane for Los Angeles. The older brother complains about taking an airplane and fears for his life, telling his brother about the crashes that every airline has had. The younger brother becomes annoyed and tells him that every airline has crashed at one point or anotherRead MoreAutism Spectrum Disorders And Its Effects3072 Words   |  13 PagesAutism spectrum disorders, or ASDs, are a set of disorders of neural brain development with many causes at their roots, and while recent research has determined several potential causes as to why the disorder occurs, its ambiguity raises an additional question of to what extent the general public understands the reality of the disorder. The various disorders include: autistic disorder, Asperger syndrome, Rett syndrome, childhood disintegrative disorder, and pervasive developmental disorder-not otherwiseRead More Autism in the Media Essay2151 Words   |  9 PagesAutism in the Media      Ã‚   Weepinbell, w-e-e-p-i-n-b-e-l-l; Tentacool, t-e-n-t-a-c-o-o-l ; Geodude . . . , yelled Connor. We were playing his favorite game - identify and spell the names of all 156 Pokà ªmon characters. Connor is a three-year-old boy I worked with as part of the SonRise therapy that his mother organized after he was diagnosed with autism. During my thrice-weekly Connor-directed playtime visits, I entered his world instead of making him enter mine and encouraged eye contactRead MoreAutism Spectrum Disorder ( Asd )1789 Words   |  8 PagesAutism Spectrum Disorder Autism spectrum disorder (ASD) is the name for a group of developmental disorders. ASD is a complex disorder and each individual that suffers from it has a unique set of conditions. The symptoms of individuals with ASD vary in severity. (Lilienfeld et al., 2017, p. 603) The autism spectrum includes classical autism, Asperger s syndrome, Rett syndrome, childhood disintegrative disorder, and pervasive developmental disorder not otherwise specified (PDD-NOS). These disordersRead MoreRain Man By Barry Levinson1267 Words   |  6 PagesRain Man (Johnson, M. Miller, R. 1988) is a motion picture featuring the selfish main character, Charlie Babbitt, and his struggles while trying to look after his brother in order to receive half of his father’s inheritance. We follow Charlie and his brother, Raymond Babbitt, who has autism, through their first meeting until Raymond is taken to a mental institution. Rain Man is an original screenplay written by Barry Morrow and directed by Barry L evinson (Rain Man 2016). Our first understanding