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High Marnham Power Station was a former coal-fired power station. It was demolished on 15 July 2012, all five cooling towers being detonated on the same day. It was located in Nottinghamshire, to the west of the River Trent, approximately north of the village of Marnham. High Marnham was the most southerly of three power stations which lined the River Trent, known locally as Megawatt Valley, the others being West Burton and Cottam. The station was constructed by the CEGB Northern Project Group, overseen by resident engineer Douglas Derbyshire and the main contractor Alfred McAlpine. The power station was constructed on a "green field site", started in November 1955 and fully commissioned by 1962. With a total generating capacity of 1000 MW (), it was the first 1000 MW power station built and commissioned in Europe, to operate at higher boiler operational temperature / pressure limits than ever previously commissioned. ==Boiler plant== Designed and built by International Combustion Ltd., four boiler units, each weighing about 14,000 tons, were suspended on beams and support columns for a vertical expansion of . Each boiler was built in twin furnace construction with bore tubes, all connected to a common drum at the top of the boiler, and fitted with safety valves set at . One furnace carried the superheat pendants, connected to the boiler drum top and to an outlet header, fitted with a safety valve set at . The second furnace carried the reheat pendants connected to an inlet header from the HP cylinder exhaust and to an outlet header to the turbine IP cylinder. The lower section of the furnace corners contained a wind box with the pulverised fuel nozzles and retractable oil burners. Fuel nozzles and burners were aligned at an imaginary circle in the furnace ensuring an even heat distribution. Pulverised fuel nozzles were provided with vertical movement to control temperature conditions. At the bottom of each furnace, the front and rear wall tubes were formed into an inward slope where the tubes were bent back (forming a nose and gap) to their original vertical wall alignment terminating at their front and rear bottom furnace water tube headers. A steel skirt was fitted around each furnace base. (ash hoppers ) Water circulation within the boiler furnace was assisted by fully immersed electrical pumps manufactured by Hayward Tyler Co. The pulverised fuel plant was built and installed by International Combustion Ltd. Four Lopulco coal roller mills with pulverised coal fans per boiler were located in the boiler house basement. Coal was fed from overhead bunkers by speed-regulated drum feeders to the mills and crushed to fine dust by three 7.5 ton roller doors per mill, then blown into the wind boxes through pipework and the PF nozzles. Combustion air was delivered by two forced draught fans located above the coal bunkers taking warm air from above the boiler roof casing, and discharging it though rotating heat exchangers to the furnace wind boxes. The spent hot gases were drawn from the furnaces through the pendants, water tube economisers, rotating heat exchanger, cyclone dust collectors and electrostatic precipitators, by two induced draught fans before discharging gasses into the chimney flu ducts and up the high chimneys. Heavy combustion products fell into basement mounted hoppers with water troughs under each furnace that engaged with the bottom furnace header casing skirt. The hoppers were emptied by a water jet/sluice arrangement into an ash receiving pit. 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「High Marnham Power Station」の詳細全文を読む スポンサード リンク
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