OCR Text |
Show Although the power plant operators did their best to supply all the information requested, some data were not readily available, and, hence, were not supplied. For example, not all power plant operators had complete coal analysis data available. To supplement the data provided by the utilities, Battelle arranged for some 60 coal analyses to be conducted on samples of coal that the utilities provided. Still, not all questionnaires are complete, and, thus, the groups of plants included in various analyses of the data vary according to the number of plants supplying complete data for those factors being examined. Where a plant was fired with several coals, the "worst case" coal analysis was used in calculating slagging parameters. Concerning slagging and fouling data, the plant operators were asked to supply data on the frequency of slagging and/or fouling occurrences at the following locations: Slagging Fouling Burner area First convection pass Hopper slopes Second convection pass Area above burners, but below nose Third convection pass On or between pendent superheater sections Slagging and/or fouling frequency was reported as: 0 Daily or several times a week 0 Several times a month 0 Occasionally 0 Rarely or never. Besides data on the frequency of deposit problems, operators were asked to supply data on the nature (dry, fluid, etc.) and thickness of deposits, and/or the effect slagging and/or fouling has had on the load carrying capacity of the unit. in all the slagging and fouling data supplied by the operators, the data on frequency of slagging and/or fouling frequency was the most consistent and, consequentially, has received the most analysis. That data is the basis for this paper. 1-4 |