管壳式换热器壳程高黏度流体的传热强化

It is a key factor to increase heat transfer coefficien t of high viscosity fluid in the shell side for making a high performance cooler.T he heat transfer and flow resistance performance of trapezoid fin tube high visc osity fluid cooler with helical or segmental baffles were studied, and compared with the heat transfer coefficient of low-fin-tube cooler with segmental baffl es. Experimental results indicated that heat transfer film coefficient in the sh ell side of trapezoid fin tube cooler with entire helical baffles was 60% more h igher than that of low-fin-tube cooler with segmental baffles,and pressure dr op was lower by 40%. Heat transfer film coefficient in the shell side of trapezo id fin tube cooler with entire helical baffles was 20% more higher than that of trapezoid-fin tube cooler with segmental baffles, and pressure drop was lower b y 50%.Heat transfer film coefficient in the shell side of trapezoid fin tube coo ler with entire helical baffles was 10% higher than that of trapezoid fin tube c ooler with sectional helical baffles, and pressure drop was lower by 19%.Heat tr ansfer film coefficient in the shell side of trapezoid fin tube cooler with segm ental baffles was 30% more higher than that of low-fin-tube cooler with segmen tal baffles, and pressure drop remained unchanged.

氨水改性活性炭纤维吸附苯乙烯的性能

主要研究采用氨水对活性炭纤维ACF表面进行改性,制备了3种不同的改性ACF,测定ACF孔结构和表面酸碱基团,并测定了苯乙烯在改性ACF床层的吸附透过曲线,讨论了改性ACF的孔结构和表面酸碱基团对其吸附性能的影响。结果表明,与原始ACF相比,经氨水改性后的活性炭纤维ACF其表面碱性基团含量、孔容及其比表面积增加,从而明显提高了对苯乙烯的吸附容量;用浓度为6mol/L的氨水改性的ACF2其微孔孔容及其比表面积最大,其对苯乙烯的吸附容量也最大。

金属离子改性活性炭对二氯甲烷脱附活化能的影响

主要研究了金属离子改性活性炭对二氯甲烷脱附活化能的影响。通过浸渍法分别将6种不同金属离子负载在活性炭表面,采用ASAP2010M测定该系列改性活性炭的孔径分布和比表面积,利用程序升温脱附技术测定了二氯甲烷在系列改性活性炭上的脱附活化能,应用软硬酸碱理论分析和讨论了活性炭表面负载不同金属离子对二氯甲烷脱附活化能的影响。结果表明,二氯甲烷在Al(Ⅲ)/SY-6AC、Li(Ⅰ)/SY-6AC、Mg(Ⅱ)/SY-6AC、Fe(Ⅲ)/SY-6AC和Ca(Ⅱ)/SY-6AC的脱附活化能高于其在原始活性炭上的脱附活化能,而它在Ag(Ⅰ)/SY-6AC的脱附活化能低于在原始活性炭上的脱附活化能。根据软硬酸碱理论分类,二氯甲烷属硬碱,当活性炭表面分别负载了硬酸类金属离子Al3+、Li+、Mg2+、Fe3+和Ca2+,则增大了表面局部硬酸度,提高了对二氯甲烷的吸附能力;Ag+属软酸,当活性炭表面负载了Ag+,则降低了活性炭表面局部硬酸度,从而降低了对二氯甲烷的吸附能力。

丙烯酸系树脂的吸附自由能特殊能分量对其吸附油烟性能的影响

主要研究了自行合成的3种吸油烟材料以及商用G-1651树脂表面的吸附自由能特殊能分量对其表面吸附油烟性能的影响。用反相气相色谱IGC测定了自行合成的聚丙烯酸异丁酯(PIBA)、聚甲基丙烯酸甲酯-甲基丙烯酸丁酯(PMMA-BMA)和聚甲基丙烯酸十二酯-丙烯酸-2-乙基己酯(PLMA-2-EHMA)3种吸油烟树脂以及商用G-1651树脂表面的吸附自由能特殊能分量。实验结果表明,4种聚合物的吸附自由能特殊能分量大小如下:G-1651树脂<PIBA<PMMA-BMA<PLMA-2-EHMA,材料表面的吸附自由能特殊能分量越小表明树脂极性越大,因此,4种吸油烟材料的极性大小为:G-1651树脂>PIBA>PMMA-BMA>PLMA-2-EHMA。4种树脂吸附油烟能力的大小顺序与其极性大小顺序恰恰相反,即PLMA-2-EHMA>PMMA-BMA>PIBA>G-1651树脂。这是由于油烟中的主要成分都是非极性或弱极性的,因此,材料表面的吸附自由能特殊能分量值越大,吸附质与吸油烟材料表面形成的吸附越牢,吸油烟材料吸附油烟的能力越强。