A five-year experiment indicated that the average loss rate of N and P in harvested products through a feeding-composting cycle was about 50% and 15%,respectively.Under high yield condition,the amount of recycled N an...A five-year experiment indicated that the average loss rate of N and P in harvested products through a feeding-composting cycle was about 50% and 15%,respectively.Under high yield condition,the amount of recycled N and P from 80% harvested products and through a feeding-composting cycle in farming systems was about 3751 and 814 kghm-2,equivalent to 25%34% of N and 32%56% of P from chemical fertilizers applied each year to the systems.The apparent recoveries of N and P in organic manure increased with the prolongation of fertilization,indicating a synergetic residual effect existed,and was 61% and 39% in average in the five-year experiment.The use of nutrients recycled in the farming systems could not only improve soil fertility,but also increase the recoveries of nutrients and reduce the use of chemical fertilizers.展开更多
文摘A five-year experiment indicated that the average loss rate of N and P in harvested products through a feeding-composting cycle was about 50% and 15%,respectively.Under high yield condition,the amount of recycled N and P from 80% harvested products and through a feeding-composting cycle in farming systems was about 3751 and 814 kghm-2,equivalent to 25%34% of N and 32%56% of P from chemical fertilizers applied each year to the systems.The apparent recoveries of N and P in organic manure increased with the prolongation of fertilization,indicating a synergetic residual effect existed,and was 61% and 39% in average in the five-year experiment.The use of nutrients recycled in the farming systems could not only improve soil fertility,but also increase the recoveries of nutrients and reduce the use of chemical fertilizers.
文摘流化床反应器在水泥工业用于生料的预分解.为了提高物料分解率,开发出一种新型的循环流化床反应器并已用于水泥生产.这种循环流化床反应器中的固气比要高于传统的预分解反应器.在建立物料氧化钙平衡的基础上,建立了关于物料循环率和碳酸盐分解率之间相互关系的数学模型.模型的计算结果与现场测试结果吻合很好.此外还提出了分解炉热稳定性的概念,并给出了相应热稳定系数的表达式.结果证明:使用循环流化床分解炉可有效改进固体物料的最终分解率.当操作温度一定( 85 0 o C)时,循环率每增加10 0 %,入窑物料的终分解率可提高8%～9%.外循环方案有助于改善分解炉的热稳定性并降低分解炉的操作温度;在终分解率不变的情况下,物料循环率每增加10 0 %,分解炉的操作温度可降低30～5 0 o C.
