Friday, April 10, 2020
Question and Career Aptitude Test free essay sample
Answer each question fully. Complete sentences are not necessary. Lesson 1 (3. 0 points) 1. What is a lifestyle? (0. 5 points) A life style is a way of living that shows the belief and opinions of a person or group 2. What is the process of earning your income sometimes called? (0. 5 points) Earning a living 3. Name at least two industries. (1. 0 points) Primary industries and manufacturing industries 4. What is an internship? (0. points) Temporary job that helps you gain work place skills 5. What is a career aptitude test? (0. 5 points) Is an exam that asks questions about thing you enjoy. Lesson 2 (3. 0 points) 1. What are classifieds? (0. 5 points) Where people can post open positions 2. What is telecommuting? (0. 5 points) is when an employee is allowed to work from a location that isnââ¬â¢t at the companys location 3. What information should a resume provide? (0. 5 points) Your job experiences 4. What is a cover letter? (0. 5 points) A page that is sometimes attached to a resume 5. We will write a custom essay sample on Question and Career Aptitude Test or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Name at least two finance careers. (1. 0 points) accountant risk manager Lesson 3 (3. 0 points) 1. What is pessimism? (0. 5 points) 2. What is conformity? (0. 5 points) 3. What might you consider when youââ¬â¢re studying the dynamics of a group? (0. 5 points) 4. What is active listening? (0. 5 points) 5. What is a stereotype? (0. 5 points) 6. What is professional development? (0. 5 points)
Tuesday, March 10, 2020
Addressing Envelopes
Addressing Envelopes Addressing Envelopes Addressing Envelopes By Maeve Maddox Heres a question from Alfonso Rodriguez from Lima, Peru: Would you be so kind as to tell me what is the correct way to write down an address when the building has no number, I think there is an abbreviation form. If any of you readers outside the U.S. know of an abbreviation that designates a building without a street number, please tell us in the comments. In the United States, new construction requires the existence of a street number before a building is built. As for older buildings, according to the person I talked to at the USPS 800 number, all buildings in towns have street numbers. Rural addresses may make use of the abbreviation RR: D.Q. Jones RR 5 Box 19 Molesville TX 77293 Many buildings have both names and street addresses. If a building is well-known in the town where it is, the name can serve in lieu of a numbered address, as long as the town and state are included. For example, an envelope addressed to someone at the Empire State Building, New York, N.Y. would probably reach its destination without the address 350 5th Ave. USPS address-reading machinery reads addresses from the bottom up: 4â⬠¦Ã¢â¬ ¦Ã¢â¬ ¦D. Q. Jones 3â⬠¦Ã¢â¬ ¦Ã¢â¬ ¦..12233 Jefferson Ave Apt 1 2â⬠¦Ã¢â¬ ¦Ã¢â¬ ¦. Newport News, VA 23602 1â⬠¦Ã¢â¬ ¦Ã¢â¬ ¦Ã¢â¬ ¦USA According to the official USPS guidelines, designations such as Apt (apartment), Dept (department), and Ste (suite) go on the same line as the street address: 234 Hilltop Dr Apt 504 Greenwich PA 23853 NOT 234 Hilltop Dr Apt 504 Greenwich PA 23853 In the event that the space available for the address is not large enough for Apt to be written out, the symbol # can be used in its place: 234 Hilltop Dr #504 Greenwich PA 23853 It a street address is especially long, some of the vowels may be omitted. For example, 23 Espendhade-Dogwood Terrace could be shortened to: 23 Espnshd-Dgwd Ter. Want to improve your English in five minutes a day? Get a subscription and start receiving our writing tips and exercises daily! Keep learning! Browse the Business Writing category, check our popular posts, or choose a related post below:20 Great Opening Lines to Inspire the Start of Your Story10 Techniques for More Precise Writing15 English Words of Indian Origin
Saturday, February 22, 2020
Negotiation Journal Essay Example | Topics and Well Written Essays - 2500 words
Negotiation Journal - Essay Example The outcome of a negotiation will often depend on the manner in which the parties carry out the negotiations. In order to engage meaningfully in any negotiation, it is necessary to develop a multi-pronged strategy that seeks to address some of the major concerns brought out by the competing parties. A good negotiator must begin from a clear and concise understanding of the issues at the center of the conflict. In many cases, this necessarily involves an awareness of the points of strengths and weaknesses of all the parties involved. A moderation of factual analysis of the issues and the power of persuasion is one of the ways that have always proven resourceful in the course of any negotiation. The art and science of negotiation entails the adoption of flexible approaches. The methods to be used in any negotiations should, in most cases, be determined by the specifics of the problem. Depending on the level of complexity of any situation, the process of negotiation may require the incl usion of the counsel of experts on some specific matters. The inclusion of expert opinions could serve to increase the cooperation of the parties involved in a conflict or disagreement because professional facts are always neutral. This strategy has often worked in negotiations that involve the settling of some technical details, which may not be easily comprehensible to one or more of the parties involved in a conflict. Finally, all negotiators must guard against the temptations of succumbing to presumptions, stereotypes, prejudice, or open bias. Such tendencies usually compromise their levels of neutrality and incur the displeasure and non-cooperation of some parties involved in negotiations. All negotiations should be carried out in sensitive and delicate processes, which involve clear attention to the core issues and the underlying concerns. The use of timelines while carrying out negotiations is an important strategy of measuring the amount of progress and success. In some case s, the process of negotiation may require occasional revision of strategies in order to fulfill certain desired
Thursday, February 6, 2020
Cultural Relativism Essay Example | Topics and Well Written Essays - 2000 words
Cultural Relativism - Essay Example Cultural relativism is related to a natural theory of evolution that views the cultural and linguistic diversity of human civilization globally as related to unique aspects of geographical isolation and parallel development. Maria Baghramian traces cultural relativism as back as Herodotus, and cites the woks of Montaigne, Dilthey ("Patterns of Culture"), and Frank Boas as the important figures of the development of this movement. (Baghramian, 2004) The main aspect of the development of cultural relativism historically also includes the interrelation of ideas between Darwin, Dewey, and Boas. (Strauss, 2011) Darwinââ¬â¢s work in the Galapagos influenced Boasââ¬â¢ conception of cultural diversity by allowing him to see the patterns of evolution in language and culture that proceeded on the same fundamental lines as the development of diversity in species as Darwin described. This also led him to value the history and lineage of each culture as an essential characteristic of cultur al relativism. (NNDB, 2011) The Darwinian aspects of cultural relativism made it an attractive methodology for the study of global cultures in anthropology. Yet, with cultural relativism there also developed a basis of moral relativism, which in some ways was posited in a manner that reflected the scientific method in social sciences, but which also removed moral criticism of cultural practices from academic research. For example, in this context foot-binding, as described by, Pang-Mei Natasha Chang in ââ¬Å"Bound Feet & Western Dress: A Memoir,â⬠was practiced traditionally in Chinese society, though it created immense pain and suffering in the girls themselves. With cultural relativity in the practice of anthropology, researchers are required to suspend judgment and evaluate foot-binding within the socio-cultural understanding of Chinese society and its indigenous values and morality. This investigates how foot ââ¬âbinding relates to other cultural traditions, rituals, and hierarchies, but it fails to take a stand on the morality of the practice in universal teams, believing that the question is beyond the anthropological or scientific method. (Glazer, 1996) Thus, in this manner it can be argued that foot-binding was so widely accepted of a practice, that it was not immoral because it was the common, accepted basis of society. In this sense, there are no universals, only cultural and moral relativism in patterns of human evolution. However, looking at description from the girls themselves, who describe their motivations at the time, it is clear that many girls opposed it themselves, in their own minds and suffering, but were simply too lacking in respect politically and socially without power, that they were abused on a mass scale. (Celliana, 2010) The question of the mass-practice of harmful, immoral, or violent practices culturally is viewed through our contemporary moral value system, which taints our own judgment from that of the dispassionate objectivism which cultural re lativism is based on, but we have to continue to reform society to outlaw, abolish, and reform harmful practices from history that have no legitimate foundation. In Pang-Mei Natasha Changââ¬â¢s ââ¬Å"Bound Feet & Western Dress: A Memoir,â⬠the character Chang Yu-I has her feet bound by her mother, who follows the ancient tradition like most other women in the society. Chang Yu-I as a child is shown to resist the process and ultimately forces her parents to stop torturing her is this way. This is used symbolically as a means to foreshadow Chang Yu-Iââ¬â¢s role in becoming one of the first ââ¬Å"modern womenâ⬠in China, and to pioneer divorce in a society where it was unknown and unaccepted historically. The issues of arranged marriages, forced marriages, and practices like foot-binding in
Tuesday, January 28, 2020
Investigating motion using video processing software Essay Example for Free
Investigating motion using video processing software Essay We switched on the laptop and connected the web cam into the USB. Once this was done we made sure that the web cam was working correctly and as soon as this watched checked we began to set up the practical part of the experiment. We then pressed record on the web cam using the software VISILOG and recorded the ball being thrown in the air next to a vertical ruler (one metre). Once this had been done we stopped the recording and the replayed the video and once we were happy, using the software, we recorded the position of the ball frame by frame. Below are the results for the first part of the experiment: Results: Time (s) Height (m) Speed (m/s) Acceleration (m/s2)à We can then draw a graph using the results and the first graph I have drawn (graph one) is of height of squash ball against time taken. Therefore, as we can see from the graph if a tangent is drawn we can calculate the gradient. The gradient of both sides of the parabola graph is shown on graph one. From the graph we can that as the squash ball is thrown the height of it increases as time increases and as it reaches its peak the ball speed is expected to decrease due to forces acting on (gravity) and therefore the ball drops down again. The gradient of the graph also calculates the speed (which can be seen of the graph) of the ball because of the formula: Distance = Speed à Time therefore Speed = Distance / Time From these results a second graph of speed against time can also be made, which is graph two. Again from this graph we can draw tangents and then work out the gradient. Using the gradient we can also work out the acceleration due to the formula: Acceleration = change in speed / change in time Therefore acceleration = gradient. Part Two Method: We used the same equipment for the second stage of the experiment but instead of recording the ball thrown in the air we recorded it as a projectile. To measure the displacement we used metre rules to measure horizontally as well as vertically. Below are the results from the experiment: Results: See next page! From this table we can draw out a lot of information and from this I have produced a graph of horizontal displacement and vertical displacement (graph three). From the graph we can see that as horizontal displacement increases so does vertical displacement until its peak of 0. 34 m. once the squash ball reaches this height it begins to fall back down due forces acting on it. After the vertical height reaches its peak it starts to decrease but the horizontal displacement continues to increase. From the graph we can also calculate the gradient, which I have done and this can be seen on the graph. Part Three Method: We got a step ladder and to the top of it we attached a wooden beam to it using clamps. Then we got three springs and attached them together and once this was done we attached the springs to the wooden beam using string. We then added a mass to the springs and recorded the oscillations it did using the camera. Below are the results for this: Results: See next page! From the results (which is a rather long set of data) we can produce a graph and this graph is a sine wave. Within the wave, it can be seen that just about 4 oscillations have been made by the spring. The time taken for 1 oscillation is called the period T. In this case the period T for 1 oscillation is about 1. 31 seconds as shown on the graph. The number of oscillations per unit time is the frequency, f = 1 / T. Therefore, using the formula we can calculate the frequency of one oscillation, which is: f = 1 / T f = 1 / 1. 31 f = 0. 763358778 f = 0. 76 Hz Furthermore as the weights on the spring move about on a fixed point it means that the wave can be described as a single harmonic motion and the acceleration is proportional to its displacement (see graph four for more details) Conclusion: Therefore, in conclusion I have shown many things in this three part experiment. For each part, I have produced graphs and shown the results table that I have analysed as well. For the first part of the experiment we can see that from the graphs the squash balls speed increases as it let go from the hand and then as it reaches its peak it begins to lose its speed and comes down, which is also due to forces acting upon the graph. Part two of the experiment is similar in respects and the difference is that it was a projectile instead. And the third part shows the spring oscillating from a ladder when a weight is attached to it. For more on these look at the graphs I have produced and the analysis beneath each part of the experiment.
Monday, January 20, 2020
Bringing Up Play, Film, and Philosophy :: Essays Papers
Bringing Up Play, Film, and Philosophy (1) Wittgenstein once said, ââ¬Å"A typical America film, naive and silly, can for all its silliness and even by means of itââ¬â be instructive . . . I have often learnt from a silly American film.â⬠(Wittgenstein 57e). He is pointing out that the humor, and the means of humor, in some films can be a tool of instruction. The ability of film to cause a reaction like laughter is of philosophical interest. While Wittgensteinââ¬â¢s comment is itself playful and dense, it directs our attention to a philosophical aspect of some films. Understood in a wider scope, I believe the comment is a terse philosophy of film. Understood in an even wider scope, we can see it as a terse theory of philosophical method. (2) Exploring implications of Wittgensteinââ¬â¢s comment, however, is not my intention in this essay. I will not explain how we can profit philosophically by examining film. My intention is to show how we can. (3) When Wittgenstein admits he found some films instructive, he very well could have admitted Howard Hawkââ¬â¢s film entitled Bringing Up Baby. Despite the silliness of the film, even by means of it, Bringing Up Baby explores the role of play in the nature of romantic relationships. I argue that in the film a relationship that is principally animated by game-play is legitimate. We learn that game-play enters into the justification of a true relationship.[1] (4) Johannes Huizinga symptomatically describes play as, ââ¬Å" . . . a free activity standing quite consciously outside ââ¬Ëordinaryââ¬â¢ life as being ââ¬Ënot serious,ââ¬â¢ but at the same time absorbing the player intensely and utterly. It is an activity connected with no material interest and no profit can be gained by it. It proceeds within its own proper boundaries of time and space according to fixed rules and in an orderly manner.â⬠(Huizinga 13). Play is defined as an open-ended set of ââ¬Ënon-seriousââ¬â¢ activities, chosen of free will in lieu of ââ¬Ëseriousââ¬â¢ or ââ¬Ëordinaryââ¬â¢ activities. The distinction between ââ¬Ëseriousââ¬â¢ and ââ¬Ënon-seriousââ¬â¢ is not intended to characterize the mental state of a player because, more often than not, a silly game is still a mentally absorbing activity.
Sunday, January 12, 2020
Advantages of Geothermal Power Plants
Advantages of Geothermal Power PlantsGeothermal power plants are used for production of electricity from geothermal energy. The traditional thermal power plants need fuel for generating electricity while geothermal powre plants don't need fuel. Here are some of the advantages of generating electricity from geothermal energy. Advantages of using Geothermal Energy for Producing PowerGeothermal energy is the energy stored below the earthââ¬â¢s crust. Due to heat below the earthââ¬â¢s crust water gets heated and also sometimes gets converted into steam. This hot water and steam can be used for generating electricity. Here are the advantages of using geothermal energy for producing electricity: 1) No fuel is required: The thermal and nuclear power plants use fossil and nuclear fuels respectively to heat water and generate steam for production of electricity.The geothermal power plants use the readily available hot water from the geothermal reservoir so no fuel is required. 2) Clean source of power: The fuels used in conventional thermal power plants produce lots of toxic gases and particulate matter polluting the surrounding atmosphere. Electricity can be produced from geothermal reservoir without creating any air-pollution. 3) Less area is required: The land required for the geothermal power plant per megawatt of power produced is much lesser than that required for the other types of power plants. 4) Unhindered production of power: The energy from geothermal reservoir is available 24 hours a day and all the days of the year without any breakage or change during varying seasons, natural disaster and political turmoil. Thus geothermal energy is the reliable source for producing electricity continuously without any hindrance.Parts of a Geothermal Power PlantGeothermal Vents The geothermal vent is the first component of a geothermal plant. A geothermal vent is a deep well drilled into the Earth that the power plant uses to tap into the Earth's heat. A geothermal plant may have two goals for its vent; most current geothermal plants draw superheated, pressurized waterà upward; these are called flash steam plants. Geothermal plants may also simply dig far enough underground, as many as three kilometers, to reach a point where the Earth is warm enough to boil water, these are called dry steam vents. Steam GeneratorAnother key component of a geothermal plant is the steam production unit, which can take multiple forms. In a flash steam vent, superheated pressurized water is drawn from its place underground to low-pressure tanks. The pressure of the Earth kept the water in liquid form despite its high temperature, and by removing that pressure the hot water instantly turns to steam, hence the term flash steam. In a dry steam plant, the plant technicians pump water to the bottom of the vent where the Earth's heat boils the water and turns it into steam.TurbineRegardless of the plant type, both flash steam and dry steam plants pump the steam from the geothermal vent to a large turbine. The steam passes this turbine, turning it in the process. This turbine is attached to an electric generator, and as the turbine turns the generator turns the mechanical energy into electric energy, thus converting the heat from the Earth into usable electricity.CondenserAfter the steam passes through the turbine, it continues to a condenser chamber. This chamber condenses the steam back into liquid water by cooling it. The excess heat lost as the steam turns to liquid water may be used for other applications, such as heating or greenhouse farming. The cooled liquid water is then typically pumped back into the ground to either restart the boiling process for dry steam or to replenish the natural heated aquifer for flash steam plants.Disadvantages of Geothermal EnergyGeothermal energy is a key contender for future electricity production in various countries across the globe. This however, doesn't mean that geothermal energy comes without its dis advantages, many of which are explained below.The Disadvantages AvailabilityThe availability of geothermal energy that is capable of feeding geothermal power stations is limited. This intense energy source is often only available in countries where geothermal activity is at its peak, mainly tectonic/volcanic regions such as Iceland. Significant Investment Required ââ¬â A significant investment is often required prior to building a geothermal power station. Geological surveys have to be undertaken to ensure the location is suitable for geothermal electricity production before any potential installation work can go ahead. It's often costly to transport any required materials to remote locations where there is sufficient geothermal activity.Harmful Gas Potential ââ¬â Geothermal power stations have the potential to release harmful gases into the air. Toxic gases exist deep beneath the ground in various regions and can sometimes be released via the infrastructure used by geotherm al power stations. Most modern geothermal power plants have systems and procedures in places to deal with these harmful gases. Localised Supply ââ¬â As geothermal is trapped beneath our feet, we cannot extract, store and transport this energy source to other countries as we do with fossil fuels such as oil, coal and gas. Geothermal energy has to be used at source to generate electricity, thus providing a supply of electricity for the electrical grid system of only the source country.The Steam Can Stop ââ¬â Geothermal power stations have the potential to cool the rocks beneath them buried deep under the ground. If the rocks are cooled via too much water flowing into the well, they will no longer be able to produce the steam required to turn a generator, thus rendering a site useless and resulting in significant losses for any company making use of geothermal energy at that location. Visual Pollution ââ¬â Geothermal power stations, as with many other power station designs can be unsightly and provide visual pollution. Networks of pipe systems have to be utilised for production purposes and many people are opposed to the sight of these. ââ¬âAdvantages of Geothermal Energy Geothermal energy is widely considered as a key contender for future electricity production in various corners of the earth. Countries including Iceland, the USA and New Zealand already make use of this renewable energy source to provide electricity on a significant scale. There are many advantages relating to the use of geothermal energy and these are describedà below. The AdvantagesEnvironmentally Friendly ââ¬â Geothermal energy is a renewable energy source that's highly environmentally friendly. Little disruption is made to the environment as a result of the various processes that are used to harness this energy source in order to provide electricity. Few chemicals and pollutants feature in geothermal electricity production. Highly Efficient ââ¬â Geothermal energy is highly efficient and can be used to provide electricity in select areas or even to provide heating for our homes and business on a much wider scale via the use of ground source heat pumps.Cost Effective ââ¬â As geothermal power stations are relatively small and less complex than large fossil fuel alternatives, they are highly cost effective, especially when they are placed in areas of high geological/tectonic activity where magma is closer to the earth's crust when compared with other locations. Job Creation ââ¬â The introduction of geothermal energy systems on both an industrial and domestic scale has helped to boost jobs in many different countries. This is a key advantage for areas that may have already been experiencing job shortages. Land Value ââ¬â Another advantage of geothermal energy and tied into the cost effectiveness of this energy source is land value.Geothermal power stations are often placed in areas of high geological activity where land values may be lo w due to obvious reasons. This helps to provide cost savings for energy companies that wish to make use of geothermal activity. Almost Infinite ââ¬â Although geothermal activity in a particular area is actually finite, this is likely to be available for anywhere between 5,000 and 1,000,000 years. This huge time scale means geothermal energy is almost infinite and will be able to long live out many fossil fuel alternatives. Always On ââ¬â As long as geothermal activity is present in a particular region, this energy source will always be on and will be fairly constant.This means that unlike solar, wind, wave and tidal alternatives, geothermal energy can provide continuous electricity production whatever the weather. Very Quiet ââ¬â Another significant advantage of geothermal energy is how quiet it can be. Geothermal energy is the electric car of power stations and is likely to provide little noise pollution to nearby residents. ââ¬âGeothermal Power PlantA geothermal po wer plant uses its geothermal activity to generate power. This type of natural energy production is extremely environmentally friendly and used in many geothermal hot spots around the globe. To harness the energy, deep holes are drilled into the earth (much like when drilling for oil) until a significant geothermal hot spot is found. When the heat source has been discovered, a pipe is attached deep down inside the hole which allows hot steam from deep within the earths crust to rise up to the surface. The pressurized steam is then channeled into a turbine which begins to turn under the large force of the steam. This turbine is linked to the generator and so the generator also begins to turn, generating electricity.We then pump cold water down a new pipe which is heated by the earth and then sent back up the first pipe to repeat the process. The main problems with geothermal energy is that firstly, you must not pump too much cold water into the earth, as this could could cool the roc ks too much, resulting in your geothermal heat source cooling down. secondly, geothermal power plants must be careful of escaping gases from deep within the earth. We suggest if you would like to learn more on this topic, you take a look at our advantages of geothermal energy, and our disadvantages of geothermal energy articles.A very good way of thinking about geothermal energy is remembering that all our continents lie on molten rock deep within the earth, this rock produces tremendous levels of heat that we are able to extract, just think of your nation lying on a bed of fire. Geothermal power is one of the most renewable energy sources that exists on our planet today, the earth will contain this heat for our lifetime. If this heat disappears, our planet will become too cold to survive on.You can purchase small scale geothermal equipment for your home yet this works in a different manner to geothermal power stations. The power stations extract the heat directly from deep within t he earth, whereas home geothermal hot water equipment absorbs heat over a lengthy period of time from a few meters beneath your feet.Main parts of the plant are1. Coal conveyor 2. Stoker 3. Pulverizer 4. Boiler 5. Coal ash 6. Air preheater 7. Electrostatic precipitator 8. Smoke stack 9. Turbine 10. Condenser 11. Transformers 12. Cooling towers 13. Generator 14. High ââ¬â votge power linesBasic Operation :A thermal power plant basically works onRankine cycle. Coal conveyor : This is a belt type of arrangement.With this coal is transported from coal storage place in power plant to the place near by boiler. Stoker : The coal which is brought near by boiler has to put in boiler furnance for combustion.This stoker is a mechanical device for feeding coal to a furnace.Pulverizer : The coal is put in the boiler after pulverization.For this pulverizer is used.A pulverizer is a device for grinding coal for combustion in a furnace in a power plant.Types of Pulverizers Ball and Tube Mill Ba ll mill is a pulverizer that consists of a horizontal rotating cylinder, up to three diameters in length, containing a charge of tumbling or cascading steel balls, pebbles, or rods. Tube mill is a revolving cylinder of up to five diameters in length used for fine pulverization of ore, rock, and other such materials; the material, mixed with water, is fed into the chamber from one end, and passes out the other end as slime. Ring and BallThis type consists of two rings separated by a series of large balls. The lower ring rotates, while the upper ring presses down on the balls via a set of spring and adjuster assemblies. Coal is introduced into the center or side of the pulverizer (depending on the design) and is ground as the lower ring rotates causing the balls to orbit between the upper and lower rings. The coal is carried out of the mill by the flow of air moving through it. The size of the coal particals released from the grinding section of the mill is determined by a classifer s eparator. These mills are typically produced by B&W (Babcock and Wilcox).Boiler : Now that pulverized coal is put in boiler furnance.Boiler is an enclosed vessel in which water is heated and circulated until the water is turned in to steam at the required pressure.Coal is burned inside the combustion chamber of boiler.The products of combustion are nothing but gases.These gases which are at high temperature vaporize the water inside the boiler to steam.Some times this steam is further heated in a superheateras higher the steam pressure and temperature the greater efficiency the engine will have in converting the heat in steam in to mechanical work. This steam at high pressure and tempeture is used directly as a heating medium, or as the working fluid in a prime mover to convert thermal energy to mechanical work, which in turn may be converted to electrical energy. Although other fluids are sometimes used for these purposes, water is by far the most common because of its economy and suitable thermodynamic characteristics.Classification of Boilers Bolilers are classified asFire tube boilers : In fire tube boilers hot gases are passed through the tubes and water surrounds these tubes. These areà simple,compact and rugged in construction.Depending on whether the tubes are vertical or horizontal these are further classified as vertical and horizontal tube boilers.In this since the water volume is more,circulation will be poor.So they can't meet quickly the changes in steam demand.High pressures of steam are not possible,maximum pressure that can be attained is about 17.5kg/sq cm.Due to large quantity of water in the drain it requires more time for steam raising.The steam attained is generally wet,economical for low pressures.The outut of the boiler is also limited.Water tube boilers : In these boilers water is inside the tubes and hot gases are outside the tubes.They consists of drums and tubes. .They may contain any number of drums (you can see 2 drums in fig).F eed water enters the boiler to one drum (here it is drum below the boiler).This water circulates through the tubes connected external to drums.Hot gases which surrounds these tubes wil convert the water in tubes in to steam.This steam is passed through tubes and collected at the top of the drum since it is of light weight.So the drums store steam and water (upper drum).The entireà steam is collected in one drum and it is taken out from there (see in laout fig).As the movement of water in the water tubes is high, so rate of heat transfer also becomes high resulting in greater efficiency.They produce high pressure , easily accessible and can respond quickly to changes in steam demand.These are also classified as vertical,horizontal and inclined tube depending on the arrangement of the tubes.These are of less weight and less liable to explosion.Large heating surfaces can be obtained by use of large number of tubes.We can attain pressure as high as 125 kg/sq cm and temperatures from 3 15 to 575 centigrade.Superheater : Most of the modern boliers are having superheater and reheater arrangement. Superheater is a component of a steam-generating unit in which steam, after it has left the boiler drum, is heated above its saturation temperature. The amount of superheat added to the steam is influenced by the location, arrangement, and amount of superheater surface installed, as well as the rating of the boiler. The superheater may consist of one or more stages of tube banks arranged to effectively transfer heat from the products of combustion.Superheaters are classified as convection , radiant or combination of these.Reheater : Some of the heat of superheated steam is used to rotate the turbine where it loses some of its energy.Reheater is also steam boiler component in which heat is added to this intermediate-pressure steam, which has given up some of its energy in expansion through the high-pressure turbine. The steam after reheating is used to rotate the second stea m turbine (see Layout fig) where the heat is converted to mechanical energy.This mechanical energy is used to run the alternator, which is coupled to turbine , there by generating elecrical energy.Condenser : Steam after rotating staem turbine comes to condenser.Condenser refers here to the shell and tube heat exchanger (or surface condenser) installed at the outlet of every steam turbine in Thermal power stations of utility companies generally. These condensers are heat exchangers which convert steam from its gaseous to its liquid state, also known as phase transition. In so doing, the latent heat of steam is given out inside theà condenser. Where water is in short supply an air cooled condenser is often used. An air cooled condenser is however significantly more expensive and cannot achieve as low a steam turbine backpressure (and therefore less efficient) as a surface condenser.The purpose is to condense the outlet (or exhaust) steam from steam turbine to obtain maximum efficie ncy and also to get the condensed steam in the form of pure water, otherwise known as condensate, back to steam generator or (boiler) as boiler feed water.Why it is required ?The steam turbine itself is a device to convert the heat in steam to mechanical power. The difference between the heat of steam per unit weight at the inlet to turbine and the heat of steam per unit weight at the outlet to turbine represents the heat given out (or heat drop) in the steam turbine which is converted to mechanical power. The heat drop per unit weight of steam is also measured by the word enthalpy drop. Therefore the more the conversion of heat per pound (or kilogram) of steam to mechanical power in the turbine, the better is its performance or otherwise known as efficiency.By condensing the exhaust steam of turbine, the exhaust pressure is brought down below atmospheric pressure from above atmospheric pressure, increasing the steam pressure drop between inlet and exhaust of steam turbine. This fur ther reduction in exhaust pressure gives out more heat per unit weight of steam input to the steam turbine, for conversion to mechanical power. Most of the heat liberated due to condensing, i.e., latent heat of steam, is carried away by the cooling medium. (water inside tubes in a surface condenser, or droplets in a spray condenser (Heller system) or air around tubes in an air-cooled condenser).Condensers are classified as (i) Jet condensers or contact condensers (ii) Surface condensers. In jet condensers the steam to be condensed mixes with the cooling water and the temperature of the condensate and the cooling water is same when leaving the condenser; and the condensate can't be recovered for use as feed water to the boiler; heat transfer is by direct conduction.In surface condensers there is no direct contact between the steam to be condensed and the circulating cooling water. There is a wall interposed between them through heat must be convectively transferred.The temperature of the condensate may be higher than the temperature of the cooling water at outlet and the condnsate is recovered as feed water to the boiler.Both the cooling water and the condensate are separetely with drawn.Because of this advantage surface condensers are used in thermal power plants.Final output of condenser is water at low temperature is passed to high pressure feed water heater,it is heated and again passed as feed water to the boiler.Since we are passing water at high temperature as feed water the temperature inside the boiler does not dcrease and boiler efficincy also maintained.Cooling Towers :The condensate (water) formed in the condeser after condensation is initially at high temperature.This hot water is passed to cooling towers.It is a tower- or building-like device in which atmospheric air (the heat receiver) circulates in direct or indirect contact with warmer water (the heat source) and the water is thereby cooled (see illustration). A cooling tower may serve as the h eat sink in a conventional thermodynamic process, such as refrigeration or steam power generation, and when it is convenient or desirable to make final heat rejection to atmospheric air. Water, acting as the heat-transfer fluid, gives up heat to atmospheric air, and thus cooled, is recirculated through the system, affording economical operation of the process.Two basic types of cooling towers are commonly used. One transfers the heat from warmer water to cooler air mainly by an evaporation heat-transfer process and is known as theevaporative or wet cooling tower.Evaporative cooling towers are classified according to the means employed for producing air circulation through them:atmospheric, natural draft, and mechanical draft. The other transfers the heat from warmer water to cooler air by a sensible heat-transfer process and is known as the nonevaporative or dry cooling tower.Nonevaporative cooling towers are classified as air-cooled condensers and as air-cooled heat exchangers, and are further classified by the means used for producing air circulation through them. These two basic types are sometimes combined, with the two cooling processes generally used in parallel or separately, and are then known as wet-dry cooling towers.Evaluation of cooling tower performance is based on cooling of a specified quantity of water through a given range and to a specified temperature approach to the wet-bulb or dry-bulb temperature for which the tower is designed. Because exact design conditions are rarely experienced in operation, estimated performance curves are frequently prepared for a specific installation, and provide a means for comparing the measured performance with design conditions.Economiser : Flue gases coming out of the boiler carry lot of heat.Function of economiser is to recover some of the heat from the heat carried away in the flue gases up the chimney and utilize for heating the feed water to the boiler.It is placed in the passage of flue gases in between the exit from the boiler and the entry to the chimney.The use of economiser results in saving in coal consumption , increase in steaming rate and high boiler efficiency but needs extra investment and increase in maintenance costs and floor area required for the plant.This is used in all modern plants.In this a large number of small diameter thin walled tubes are placed between two headers.Feed water enters the tube through one header and leaves through the other.The flue gases flow out side the tubes usually in counter flow.Air preheater : The remaining heat of flue gases is utilised by air preheater.It is a device used in steam boilers to transfer heat from the flue gases to the combustion air before the air enters the furnace. Also known as air heater; air-heating system. It is not shown in the lay out.But it is kept at a place near by where the air enters in to the boiler. The purpose of the air preheater is to recover the heat from the flue gas from the boiler to improve boiler efficiency by burning warm air which increases combustion efficiency, and reducing useful heat lost from the flue.As a consequence, the gases are also sent to the chimney or stack at a lowerà temperature, allowing simplified design of the ducting and stack. It also allows control over the temperature of gases leaving the stack (to meet emissions regulations, for example).After extracting heat flue gases are passed to elctrostatic precipitator. Electrostatic precipitator : It is a device which removes dust or other finely divided particles from flue gases by charging the particles inductively with an electric field, then attracting them to highly charged collector plates. Also known as precipitator. The process depends on two steps.In the first step the suspension passes through an electric discharge (corona discharge) area where ionization of the gas occurs. The ions produced collide with the suspended particles and confer on them an electric charge. The charged particles drift t oward an electrode of opposite sign and are deposited on the electrode where their electric charge is neutralized. The phenomenon would be more correctly designated as electrodeposition from the gas phase. The use of electrostatic precipitators has become common in numerous industrial applications.Among the advantages of the electrostatic precipitator are its ability to handle large volumes of gas, at elevated temperatures if necessary, with a reasonably small pressure drop, and the removal of particles in the micrometer range. Some of the usual applications are: (1) removal of dirt from flue gases in steam plants; (2) cleaning of air to remove fungi and bacteria in establishments producing antibiotics and other drugs, and in operating rooms; (3) cleaning of air in ventilation and air conditioning systems; (4) removal of oil mists in machine shops and acid mists in chemical process plants; (5) cleaning of blast furnace gases; (6) recovery of valuable materials such as oxides of copp er, lead, and tin; and (7) separation of rutile from zirconium sand. Smoke stack :A chimney is a system for venting hot flue gasesor smoke from a boiler, stove, furnace or fireplace to the outsideatmosphere.They are typically almost vertical to ensure that the hot gases flow smoothly, drawing air into the combustion through the chimney effect (also known as the stack effect). The space inside a chimney is called a flue. Chimneys may be found in buildings, steam locomotives and ships. In the US, the termsmokestack (colloquially, stack) is also used when referring to locomotive chimneys. The term funnel is generally used for ship chimneys and sometimes used to refer to locomotive chimneys.Chimneys are tall to increase their draw of air for combustion andà to disperse pollutants in the flue gases over a greater area so as to reduce the pollutant concentrations in compliance with regulatory or other limits. Generator : An alternator is an electromechanical device that converts mechani cal energy to alternating current electrical energy. Most alternators use a rotating magnetic field. Different geometries ââ¬â such as a linear alternator for use with stirling engines ââ¬â are also occasionally used. In principle, any AC generator can be called an alternator, but usually the word refers to small rotating machines driven by automotive and other internal combustion engines.Transformers :It is a device that transfers electric energy from one alternating-current circuit to one or more other circuits, either increasing (stepping up) or reducing (stepping down) the voltage. Uses for transformers include reducing the line voltage to operate low-voltage devices (doorbells or toy electric trains) and raising the voltage from electric generators so that electric power can be transmitted over long distances. Transformers act through electromagnetic induction; current in the primary coil induces current in the secondary coil. The secondary voltage is calculated by mult iplying the primary voltage by the ratio of the number of turns in the secondary coil to that in the primary. To see the complete operation of the plant in flash player Click here
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