THE USE OF ORGANIC COATINGS TO PROMOTE DROPWISE CONDENSATION OF STEAM
THE USE OF ORGANIC COATINGS TO PROMOTE DROPWISE CONDENSATION OF STEAM
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DOI：
10.1115/1.3248156
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发表时间：
1987-08-01
影响因子：
--
通讯作者：
ROSE, JW
中科院分区：
文献类型：
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作者：
HOLDEN, KM;WANNIARACHCHI, AS;ROSE, JW
评价了十四种聚合物涂层促进和维持蒸汽滴状冷凝的能力。九个涂层采用含氟聚合物作为主要成分;四个采用烃类，一个采用硅酮。将每种涂层施加到25平方毫米×约1毫米厚的黄铜、铜、铜-镍和钛金属基材上。当暴露于大气压下的蒸汽时，目视评价每种涂层促进滴状冷凝的能力。还进行了为期22，000小时的观察。对选定的试样进行硬度和附着力测试。在持续性能的基础上，选择了六种涂层应用于直径为19 mm的铜管的外部，以进行传热评估。这些管子水平安装在一个单独的装置中，蒸汽通过该装置垂直向下流动。蒸汽侧的传热系数推断从整体测量。试验结果表明，采用聚合物涂层促进滴状冷凝，可使蒸汽侧传热系数提高5 ~ 8倍。
Fourteen polymer coatings were evaluated for their ability to promote and sustain dropwise condensation of steam. Nine of the coatings employed a fluoropolymer as a major constituent; four employed hydrocarbons and one a silicone. Each coating was applied to 25-mm-square by approximately 1-mm-thick metal substrates of brass, copper, copper–nickel, and titanium. While exposed to steam at atmospheric pressure, each coating was visually evaluated for its ability to promote dropwise condensation. Observations were also conducted over a period of 22,000 hr. Hardness and adhesion tests were performed on selected specimens. On the basis of sustained performance, six coatings were selected for application to the outside of 19-mm-dia copper tubes in order to perform a heat transfer evaluation. These tubes were mounted horizontally in a separate apparatus through which steam flowed vertically downward. Steam-side heat transfer coefficients were inferred from overall measurements. Test results indicate that the steam-side heat transfer coefficient can be increased by a factor of five to eight through the use of polymer coatings to promote dropwise condensation.