The modern steel plant receives low current, high voltage power from the generators of the electrical utility company. The purpose of the steel plant primary transformer is to step-down this voltage. The transformer thus provides high current, low voltage power for the EAF furnace. Large furnaces with transformers rated at 100MVA or higher is not uncommon.
There are usually two stages to this process. The transformer first steps-down the voltage from high to medium levels. There are different standards for a “medium-level voltage” in different countries; usually between 30 to 33 kV for Europe and Japan, but for the USA it is usually 34.5 kV. Finally, a heavy duty furnace transformer powers the EAF. This special furnace transformer is designed to allow the electric arc to operate within the desired current and voltage range.
To safeguard the EAF electrical system from the primary power supply are two types of switches: a vacuum switch and a motorized disconnect switch. These two switches are designed to isolate the EAF electrical system from the primary transformer in case of an emergency.
Other electrical systems around the EAF are the delta closure, the power cables, the current conduction arm, and the electrode holders. The power cables provide a connection between the delta closure and the current conducting arm. It is usually made of copper wires, with a rubber water jacket around the outside for water-cooling the cables. The power cable is connected with the current conducting arm, usually made of copper clad steel or aluminum alloys. This system weighs a lot less than the old bus-bar design that a lot of the older furnaces used. The current conducting arm conducts current directly from the power cable to the electrode holders. The electrode holders must withstand thermal cycling (not so much for our furnace, since our furnace should have a continuous feed) and severe mechanical loading and wear due to vibrations, torsion forces and such.
A household furnace has an output of 100,000 Btu/hr. What size electrical heating unit (in kW) would be needed to replace this?
Whereby, instead of using a separate material as a regenerator to recuperate the heat from the magnetic material, the AMR concept made use of the refrigerant itself as the regenerator [6], thus, making it an active part of the refrigeration cycle. This is possible due to the high heat capacities of common magnetocaloric materials near their Curie temperatures [25].
In recent years there has been a growing trend involving the use of closed circuit
The Lincoln Electric Company started in 1906 by James F. Lincoln in Cleveland, Ohio. His father was a minister and so in turn you can see many Christ like principals at the center of Lincolns Electric Company. James’s Golden Rule was taken from the Sermon on the Mount: Do unto others as you would have then do unto you. Through this philosophy stems many of Mr. Lincoln’s main ideas for his company such as: The Incentive Management plan, the way people communicate within the company, the bonus plan and even down to the management style.
U.S. Environmental Protection Agency. (1995). Profile of the Iron and Steel Industry. Office of Enforcement and Compliance Assurance. Washingto, DC: Office of Compliance. Retrieved February 07, 2014, from http://nepis.epa.gov/Exe/ZyNET.exe
He effectively gives the reader a crash course on the process he went through to make the machine work. Kamkwamba states, “A step-up transformer has two coils—the primary and secondary—located on either side of a core” (Kamkwamba and Mealer 210). These scientific explanations not only showcase the mistakes Kamkwamba made along the way, but also teach the reader, even if only a little bit, about the machinery and how it
· B-phase transformer (EMTU-TT01) · Feedback electronic wattmeter · Multi-range moving-iron ammeter · Instrument voltage transformer THEORY AND INTRODUCTION ----------------------- Transformers are used all over the world to step-up and step-down electricity. The transformer is one of the most commonly used electrical devices. The reason the transformer is so popular is because they range in size from 240V to well over 240kV, stepping -up and stepping-down electricity all over the world.
In the early part of this century was a time when industry was booming with growth around the installation of major railroads. With this growth came the transatlantic cable, the telegraph, and a whole lot of steel. Steel would be needed in the construction of these new transportation systems and communications were now possible between businesses and industries. (Wren, 2005)
Since early 2003 the Electrical Inspectorate has been working to raise public awareness of Residual Current Devices (RCDs), with the aim of eventually enforcing the use of these devices as recommended by the standard adopted by the St. Lucia Bureau of Standards for wiring of buildings SLNS/BS 7671: 2001- Requirements for Electrical Installations ¡V IEE Wiring Regulations ¡V Sixteenth Edition. These Regulations though only recently adopted by the Bureau of Standards is the Regulations referred to by the St. Lucia Electricity regulations of 1973 as the standard of wiring of buildings. For a very long time the cost of these devices had proven prohibitive for the enforcement of the requirement. However, it is now believed that safety concerns as it relates to electrical hazards such as fire and electrocution far outweigh the cost of these devices
The electrostatic precipitator (ESP) is a machine used in factories, to clean out the waste solid particle, for example ash from the exhaust gas, allowing clean exhaust gas exit through the chimney. The electrostatic precipitator functions by using first allow the exhaust gas with the waste solid particles pass through the Nozzle as shown in the diagram below. Then the exhaust gas passes through inlet gas distribution, which evenly distributes the gas as shown below in a turquoise color, and starts going through the Discharge electrodes and the collector plates, which is shown in the diagram red and blue respectively. The discharge electrodes, which are powered by high voltage direct current, ionize the gas along with the other solid waste particles negatively. The collector plates are also charged with high voltage electricity, but it is positively charged, therefore attracting the negatively charged solid particle, because oppositely charged particles attract. This allows the clean exhaust gas pass through the other end, while the solid waste particles are trapped in the collector plates. Eventually when there are enough solid waste particles collected on the collector plates, the collect plates shakes off the collected waste, where it drops to the bottom of the shaft as shown in the diagram as “Hopper”.
The basis for the understanding of the heat treatment of steels is the Fe-C phase diagram. Because it is well explained in earlier volumes of Metals Handbook and in many elementary textbooks, the stable iron-graphite diagram and the metastable Fe-Fe3 C diagram. The stable condition usually takes a very long time to develop, especially in the low-temperature and low-carbon range, and therefore the metastable diagram is of more interest. The Fe-C diagram shows which phases are to be expected at equilibrium for different combinations of carbon concentration and temperature. We distinguish at the low-carbon and ferrite, which can at most dissolve 0.028 wt% C at 727 oC and austenite which can dissolve 2.11 wt% C at 1148 oC. At the carbon-rich side we find cementite. Of less interest, except for highly alloyed steels, is the d-ferrite existing at the highest temperatures. Between the single-phase fields are found regions with mixtures of two phases, such as ferrite + cementite, austenite + cementite, and ferrite + austenite. At the highest temperatures, the liquid phase field can be found and below this are the two phase fields liquid + austenite, liquid + cementite, and liquid + d-ferrite. In heat treating of steels the liquid phase is always avoided. Some important boundaries at single-phase fields have been given special names. These include: the carbon content at which the minimum austenite temperature is attained is called the eutectoid carbon content. The ferrite-cementite phase mixture of this composition formed during cooling has a characteristic appearance and is called pearlite and can be treated as a microstructural entity or microconstituent. It is an aggregate of alternating ferrite and cementite particles dispersed with a ferrite matrix after extended holding close to A1. The Fe-C diagram is of experimental origin. The knowledge of the thermodynamic principles and modern thermodynamic data now permits very accurate calculations of this diagram.
Refrigerators and stoves are the main product lines in which Atlas Eléctrica has its core competences. They are also working fine due to the production system.
- - - . "Western Electric #202 Desk Phone." n.pag. Online: Available: http://www.cyber-comm.net/~chuck/we202.html, Mar. 31, 1999.
Electrical engineering deals with electricity, electro-magnetism and electronics. It also covers power, control systems, telecommunications and signal processing. These engineers are usually concerned with large-scale electrical systems such as motor control and power transmission, as well as utilizing electricity to transmit energy. Electrical engineers may work on a diverse range of technologies, from the design of household appliances, lighting
In power stations electricians need to use a variety of device to ensure that they are doing the job correctly. The four essential things an electrician needs to consider is earth wire, double insulation, fuse box and a residual circuit breaker. These four things are essential because they help to increase the health and safety of workers.