Search results
Results from the WOW.Com Content Network
An electric arc furnace (EAF) is a furnace that heats material by means of an electric arc. Industrial arc furnaces range in size from small units of approximately one-tonne capacity (used in foundries for producing cast iron products) up to about 400-tonne units used for secondary steelmaking. Arc furnaces used in research laboratories and by ...
The voltage required to arc this distance is 327 V, which is insufficient to ignite the arcs for gaps that are either wider or narrower. For a 3.5 μm gap, the required voltage is 533 V, nearly twice as much. If 500 V were applied, it would not be sufficient to arc at the 2.85 μm distance, but would arc at a 7.5 μm distance.
An electric arc between two nails. An electric arc (or arc discharge) is an electrical breakdown of a gas that produces a prolonged electrical discharge. The current through a normally nonconductive medium such as air produces a plasma, which may produce visible light. An arc discharge is initiated either by thermionic emission or by field ...
Joule heating does not occur in superconducting materials, as these materials have zero electrical resistance in the superconducting state. Resistors create electrical noise, called Johnson–Nyquist noise. There is an intimate relationship between Johnson–Nyquist noise and Joule heating, explained by the fluctuation-dissipation theorem.
An electrical resistance heater, which is not considered efficient, has an HSPF of 3.41. [3] Depending on the system, an HSPF ≥ 9 can be considered high efficiency and worthy of a US Energy Tax Credit. [4] For instance, a system which delivers an HSPF of 7.7 will transfer 2.25 times as much heat as electricity consumed over a season. [5]
The Submerged-arc furnace for phosphorus production is a particular sub-type of electric arc furnace used to produce phosphorus and other products. Submerged arc furnaces are mainly used for the production of ferroalloys. The nomenclature submerged means that the furnace's electrodes are buried deep in the furnace burden.
Ceramic fibre is commonly used for the roof and wall of the furnace and is graded by its density and then its maximum temperature rating. For example, 8# 2,300 °F means 8 lb/ft 3 density with a maximum temperature rating of 2,300 °F. The actual service temperature rating for ceramic fiber is a bit lower than the maximum rated temperature.
The effectiveness of protective equipment is measured by its arc rating. The arc rating is the maximum incident energy resistance demonstrated by a material prior to breakopen (a hole in the material) or necessary to pass through and cause a 50% probability of second degree burns. [4] Arc rating is normally expressed in cal/cm 2 (or small ...