Rotary kiln process for iron ore oxide pellet production is hard to detect and control.Construction of one-dimensional model of temperature field in rotary kiln was described.And the results lay a solid foundation for...Rotary kiln process for iron ore oxide pellet production is hard to detect and control.Construction of one-dimensional model of temperature field in rotary kiln was described.And the results lay a solid foundation for online control.Establishment of kiln process control expert system was presented,with maximum temperature of pellet and gas temperature at the feed end as control cores,and interval estimate as control strategy.Software was developed and put into application in a pellet plant.The results show that control guidance of this system is accurate and effective.After production application for nearly one year,the compressive strength and first grade rate of pellet are increased by 86 N and 2.54%,respectively,while FeO content is 0.05% lowered.This system can reveal detailed information of real time kiln process,and provide a powerful tool for online control of pellet production.展开更多
It has been possible to pelletize wood Miscanthus mixtures （12.5%, 25% and 50%） without modifying production process settings of a softwood pellets plant. Pure Miscanthus material tested in the same conditions has l...It has been possible to pelletize wood Miscanthus mixtures （12.5%, 25% and 50%） without modifying production process settings of a softwood pellets plant. Pure Miscanthus material tested in the same conditions has led to unstable production, mainly explained by hammermill overfeeding. The unstable production has been identified as the main responsible factor of the low quality of pellets produced with pure Miscanthus for these trials. The produced pellets were tested in a 25 kW boiler and compared with agro-pellets of various origins： winter barley straw, rapeseed straw, reed, old hay, Miscanthus, and wood pellets. Results gained during these combustion trials allowed to describe combustion of these uncommon fuels and to characterize its emissions. The trials confirm general characteristics of agricultural fuel combustion： influence of the ash content on the gross calorific value, influence of the N content in the fuel on the NOx emissions, influence on the alkali content on the C12 emissions. But the influence of known parameter （S. alkali and earth alkali content） on SO2 emission might not be highlighted, while a relation with the fuel moisture content could be considered.展开更多
基金Project(NCET-05-0630) supported by Program for New Century Excellent Talents in University of China
文摘Rotary kiln process for iron ore oxide pellet production is hard to detect and control.Construction of one-dimensional model of temperature field in rotary kiln was described.And the results lay a solid foundation for online control.Establishment of kiln process control expert system was presented,with maximum temperature of pellet and gas temperature at the feed end as control cores,and interval estimate as control strategy.Software was developed and put into application in a pellet plant.The results show that control guidance of this system is accurate and effective.After production application for nearly one year,the compressive strength and first grade rate of pellet are increased by 86 N and 2.54%,respectively,while FeO content is 0.05% lowered.This system can reveal detailed information of real time kiln process,and provide a powerful tool for online control of pellet production.
文摘It has been possible to pelletize wood Miscanthus mixtures （12.5%, 25% and 50%） without modifying production process settings of a softwood pellets plant. Pure Miscanthus material tested in the same conditions has led to unstable production, mainly explained by hammermill overfeeding. The unstable production has been identified as the main responsible factor of the low quality of pellets produced with pure Miscanthus for these trials. The produced pellets were tested in a 25 kW boiler and compared with agro-pellets of various origins： winter barley straw, rapeseed straw, reed, old hay, Miscanthus, and wood pellets. Results gained during these combustion trials allowed to describe combustion of these uncommon fuels and to characterize its emissions. The trials confirm general characteristics of agricultural fuel combustion： influence of the ash content on the gross calorific value, influence of the N content in the fuel on the NOx emissions, influence on the alkali content on the C12 emissions. But the influence of known parameter （S. alkali and earth alkali content） on SO2 emission might not be highlighted, while a relation with the fuel moisture content could be considered.
