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An electrode boiler (jet type) is a type of boiler that uses electricity flowing through streams of water to create steam. The conductive and resistive properties of water are employed to carry electric current. During the operation of the boiler, it is fed with water which contains conductive substances like salts. Because the departing steam is free of these substances, conductivity of water increases as the cleaner the water, the lower the conductivity. When conductivity goes beyond certain limit, some of the water must be blown down and replaced with fresh water. The most common type of electrode boiler pumps water from the lower part of the vessel to an internal header that has nozzles that allow the water to flow to electrodes. The electrodes are connected to a high voltage A.C. source, typically 6,600 volts to 13,800 volts. If D.C. voltage is used, Electrolysis of water occurs, decomposing water into its elements H2 at the cathode(negative electrode) and O2 at the anode(positive electrode)}. Electrode boilers can work on both Single phase and Three phase supplies. The electrode boiler is 99.9% efficient with almost all the energy consumed producing steam.〔http://www.alabamapower.com/architect/technical_library/lib_sheat_ElecBoil.asp〕 The conductivity of the water and the voltage applied determine how much steam is generated in each stream of water. Generally the working pressure is maintained at 10 bar. If more pressure is needed (more steam) the controls speed up the pump and flow more water through additional nozzles. As the needed pressure is reached the pump controls the flow of water to obtain the desired steam output (in lbs per hour) at the desired pressure. The pump is controlled by a Variable Frequency Drive (VFD) so energy is not wasted. This control system can also control de-aerator pumps and controls. ==Advantages== * All electrical energy is converted to heat, and doesn't directly generate pollution nor needs a pollution control system.〔http://www.cbboilers.com/electrodeboiler.htm〕 * Electrode boiler has very quick response time. * Compact size of electrode boiler makes it easier to work with than other kinds of boiler like fossil fired boilers etc. * Electrode boilers are not directly polluting, thus they don't release any harmful gas like carbon monoxide which adversely affects the environment. * No need of a chimney. * As compared to other boilers, there is little thermal stressing, so steam raises quickly.〔http://www.emt-india.net/equipment_tips/boiler/eqp_Boiler_Types.htm〕 * Unlike fossil fuel or conventional electric boiler, no component of electrode boiler is at high temperature except the water itself, during the operation. * There is no requirement of low voltage transformer due to which High Voltage supply grid connection can be established. * None of the components in electric boiler are minimum, so easy to control and maintain. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Electrode boiler」の詳細全文を読む スポンサード リンク
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