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以湖南某停产的冶炼厂旧址的重金属废渣为研究对象,通过正交试验向废渣中添加稳定化药剂,以稳定化后废渣的浸出毒性为研究指标,确定不同药剂最优化配比。结果表明,氧化物的含量是控制浸出毒性的关键因素。根据标准HJ/T 299-2007方法,采用最优配比药剂处理后的废渣浸出毒性低于危险废弃物毒性浸出标准(GB5085.3-2007),根据标准GB 5086.1-1997方法,处理后的废渣浸出毒性也低于污水排放标准(GB8978-1996)中重金属浓度限值,重金属废渣从危险废物变为第Ⅱ类一般工业固体废物。 相似文献
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以湖南某停产的冶炼厂旧址的重金属废渣为研究对象,通过正交试验向废渣中添加稳定化药剂,以稳定化后废渣的浸出毒性为研究指标,确定不同药剂最优化配比.结果表明,氧化物的含量是控制浸出毒性的关键因素.根据标准HJ/T 299-2007方法,采用最优配比药剂处理后的废渣浸出毒性低于危险废弃物毒性浸出标准(GB5085.3-2007),根据标准GB 5086.1-1997方法,处理后的废渣浸出毒性也低于污水排放标准(GB8978-1996)中重金属浓度限值,重金属废渣从危险废物变为第Ⅱ类一般工业固体废物. 相似文献
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建立微型燃气轮机CW(交叉波浪型,Cross Wavy)原表面回热器三维周期性充分发展数值计算模型,对芯体内传热和阻力特性进行了分析,确定了质量流量和温度水平对换热量及压降的影响,给出了CW原表面芯体板内阻力、传热因子以及努塞尔数与雷诺数之间的经验关联式。传热及阻力性能分析结果表明:随着雷诺数的增大,回热器芯体单元传热系数增大,传热量逐渐增加,并且随着低压高温烟气侧的进口温度升高,传热量增加幅度增大;回热器芯体单元回热度随雷诺数的增大而减小,随燃气进口温度升高而减小。 相似文献
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本文通过建立微型燃气轮机CW(Cross Wavy)原表面回热器热-结构耦合有限元分析模型,对其在设计工况下运行后的应力进行了有限元分析,验证了回热器所选材料的可靠性,并分析了压比和燃气入口温度对回热器的应力影响。分析结果表明:不考虑热应力,只计及压力时,回热器燃气出口侧最大应力和应变高于燃气进口侧最大应力和应变;与之相反,计及热应力时,在压力和温度耦合作用下,回热器燃气进口侧最大应力和应变高于燃气出口侧最大应力和应变;无论是计及热应力还是不考虑热应力,空气通道的波谷处应力最大,并且应力沿波谷处左右对称分布,计及热应力后,其最大应力增长较大,对应各处增幅最高达到34.1%;回热器空气通道向燃气通道侧变形,空气通道变大,燃气通道减小;随着空气侧和燃气侧压比的增加,回热器通道的最大应力也随之增加,当压比增加到8.4时,已达到换热片材料的强度极限;当燃气与空气出口温度不变、回热度减小时,随着燃气入口温度增加,最大应力随之增加,燃气入口温度每增加50 K,回热器最大应力增加约2.3 MPa。研究结果为回热器的设计提供了一定的参考依据。 相似文献
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Conventional jar tests and on-line size monitoring were used to investigate the effects of slow-mixing intensity and duration on residual turbidity and floc size during charge neutralization coagulation and sweep flocculation with polyaluminum chloride. The compensatory effect of slow-mixing on coagulation performance following inadequate or excessive rapid-mixing was also examined. It is found that slow-mixing intensity has a more marked positive effect on charge neutralization coagulation than on sweep flocculation. The optimal root-mean- square velocity gradient, G, for slow-mixing is 15 s-1 for both coagulation mechanisms, and charge neutralization coagulation requires a longer slow-mixing duration. The optimal slow-mixing duration, based on residual turbidity, is longer than the time to form the largest mean flocs. The optimal product of G and mixing duration, GT, for slow-mixing during charge neutralization coagulation (13500) are higher than that during sweep flocculation (4500) and both are less than the range of values recommended by the American Water Works Association (24000-84000). The optimal GT value under various slow-mixing conditions increases with G. Appropriate extension of slow-mixing duration during charge neutralization coagulation can improve coagulation performance after an inadequate or excessive rapid-mixing duration, but during sweep flocculation, appropriate shortening of slow-mixing duration after an excessive rapid-mixing or appropriate extension of slow-mixing duration after an inadequate rapid-mixing is favorable. 相似文献
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