[PDF] Coal And Limestone Feed System Development For Atmospheric Fluidized Bed Combustion Afbc Including Tests Of The Fuller Kinyon Pump eBook

Author : M. Valk
Publisher : Elsevier
Page : 479 pages
File Size : 22,48 MB
Release : 2013-10-22
Category : Technology & Engineering
ISBN : 1483290506

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The use of fluidized bed coal combustion technology has been developed in the past decade in The Netherlands with a view to expanding the industrial use of coal as an energy supply. Various research groups from universities, institutes for applied science and from boiler industries participated and contributed to this research area. Comprehensive results of such recent experimentation and development work on atmospheric fluidized bed combustion of coal are covered in this volume. Each chapter, written by an expert, treats one specific subject and gives both the theoretical background as well as experimental results and verifications. Though the contents deal primarily with coal combustion, much information proved applicable and relevant for the combustion or incineration of other solid fuels and waste in a fluidized bed. Results of extended research and fundamental backgrounds are presented in order to provide the designer and operator of fluidized bed combustors with more complete and systematic information needed for an optimal design and operation. The design and operating experience of a full scale fluidized bed boiler are discussed and compared with the results of theoretical and experimental research on pilot plant scale.

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Page : pages
File Size : 40,22 MB
Release : 1980
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Development of a coal feeding and distribution system is one of the major requirements for successful operation of large scale atmospheric fluidized-bed boilers. Since combustion efficiency, sulfur capture, and tube corrosion are strong functions of coal distribution in the bed, the reliability of the feed system is critical. One proposed coal feeding method involves underbed feed nozzles, and pneumatic conveying is a key element in this method. Several technical problems are inherent in such systems. One program aimed at resolving these problems involves testing a pneumatic transport system constructed to represent the branch feed lines in TVA's 20 MW AFBC pilot plant. The major objective is to determine the practical limits of such operating parameters as surface moisture, transport velocity, and coal loading. In addition, correlations are being developed to predict line pressure drop as a function of the conveying parameters. Pressure drop is important because it determines the feed system pumping costs and is a good indicator of changes in the solids flow regime. Preliminary results indicate that surface moisture is the most important factor in getting coal into the transport line. Coal with up to 6 wt % surface moisture can be fed with little difficulty, but higher moisture results in severe bridging and compaction in the feed hopper and feeder mechanism. Once the coal is in the transport line, moisture level does not appear to be as important. It has also been found that within the range of particle sizes studied, the percentage of fines has little effect. In fact, as long as saltation is not occurring, the conveying characteristics of a coal-air mixture seem to depend primarily on coal loading. In general, saltation and plugging will not occur as long as superficial air velocity is above 12.2 m/sec (approx. 40 ft/sec).