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The gas suction hood, ventilation duct and scrubbing system in the equipment for recovering chrome mist have been studied. The gas speed in the duct, the selection of duct material and the chrome mist recoverer, the curvature radius of the bend pipe, the improvement of T bend and the structure of the gas suction hood are all discussed in detail, and the following suggestions are made: a) the gas speed after the recoverer should be maintained under 10m/s, b) the duct should be of plastics, 3) the effective filtering... The gas suction hood, ventilation duct and scrubbing system in the equipment for recovering chrome mist have been studied. The gas speed in the duct, the selection of duct material and the chrome mist recoverer, the curvature radius of the bend pipe, the improvement of T bend and the structure of the gas suction hood are all discussed in detail, and the following suggestions are made: a) the gas speed after the recoverer should be maintained under 10m/s, b) the duct should be of plastics, 3) the effective filtering area of the screen should be no less than twice of the cross-section of the recoverer, 4) the main air duct should be in the form of square, 5) the curvature radius of the bend pipe R=1.5-2 D, 6) windward of Tbend R=b, 7) adopting band gap screen of the hood. Through these improvements, the author believes that the efficiency of chrome mist recoverer would be much raised. 本文对铬雾回收装置中的吸风罩、风道、净化装置等进行了研究,并且提出了①回收器后的风速应控制在10m/s以下;②管道材料应采用塑料管;③回收器的网格有效过滤面积不得小于回收器断面的两倍;④主风道应做成正方形;⑤弯管曲率半径R=1.5—2D;⑥三通迎风面R=b;⑦采用条缝吸风罩等建议。经过上述改进,必将大大地提高铬雾回收器的效率。 A fatigue-creep interaction fracture map for a 12Cr1MoV heat resistant steel with holding load has been constructed, by simulation tests under practical load spectrum, together with its fractographic analysis. Based on the map a relationship between creep life and holding time, has been suggested as life prediction criterion to provide a reliable base for safe operation of thermal power plant. 本研究采用模拟实际载荷谱的力学试验,结合断口形貌分析,建立了在保载条件下的火力发电厂主蒸气管道材料12Cr1MoV钢的疲劳蠕变交互作用断裂特征图。并在此基础上获得作为寿命预测依据的蠕变断裂寿命和保载时间的依赖关系,为电厂安全运行提供可靠依据。 The HAZ ductile-brittle behaviour of two materials used for the high pressure pipes in nuclear power plants-austenitic stainless steels containing Nb and Ti was investigated with a thermo-mechanical simulating system-Gleeble 2000 by applying a Hot Tensile and Hot Ductility Test, which emphasizes physical characters of brittle cracking. It is pressented from the results that the tendency of brittleness to HAZ cracking will increases with the increase of Nb and Ti contend in the steels. The ZDR( Zero Ductility... The HAZ ductile-brittle behaviour of two materials used for the high pressure pipes in nuclear power plants-austenitic stainless steels containing Nb and Ti was investigated with a thermo-mechanical simulating system-Gleeble 2000 by applying a Hot Tensile and Hot Ductility Test, which emphasizes physical characters of brittle cracking. It is pressented from the results that the tendency of brittleness to HAZ cracking will increases with the increase of Nb and Ti contend in the steels. The ZDR( Zero Ductility Zone) of the steels containing Nb is more greater than that of the steels containing Ti. 应用热机械模拟系统Gleeble2000System,通过焊接热影响区(HAZ)致脆开裂物理本质的模拟性试验———热拉力试验,对两种某核电站用高压热水管道材料———含铌和含钛奥氏体不锈钢的HAZ韧脆性变化行为进行了测试和研究.结果表明:HAZ致脆开裂敏感性随铌、钛含量的增加而提高,且含铌钢的ZDR(零韧性区域)远大于含钛钢.
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