管翅式换热器离子交换树脂涂层

Desiccant coating with ion exchange resin on aluminum foil surface of finned tube heat exchanger

采用浸渍法将离子交换树脂（IER）浸渍于饱和氯化锂或氯化镁溶液中，并依次经过滤、洗涤及干燥得改性离子交换树脂。经粉碎后的改性离子交换树脂粉与固体粉末涂料混合成喷涂料，对管翅式换热器铝箔表面进行静电喷涂、热固化得吸湿涂层。XRD分析表明，改性前后树脂结构没有发生根本性改变；SEM表明，吸湿涂层能够均匀紧密地分散在铝箔表面，涂层厚达120gm；EDS显示出吸湿涂层各成分组成及含量；TG曲线表明，吸湿涂层失重主要集中在30～150℃及400-600℃区域，前者与吸附剂脱附有关，后者与涂料及树脂粉热分解有关；静态和动态吸附曲线显示，吸湿涂层经改性后，其吸湿性能明显提高；吸湿涂层重复性测试显示，涂层具有较高吸附及脱附稳定性。

Modified ion exchange resin （IER） was obtained by impregnating IER into the saturated LiCI or MgCl2 solution, filtering, washing and drying sequentially. The desiccant coating was produced by means of electrostatic spraying and thermocuring the mixture of the pulverized modified IER and powder coating on aluminum foil surface of finned tube heat exchanger. XRD spectra showed that IER structure had no obvious change after modification. SEM images revealed that the desiccant coating could be uniformly and closely dispersed on the surface of aluminum foil and its thickness was about 120 μm. EDS analysis showed the composition and content of the desiccant coating. TG curves indicated that the mass loss of desiccant coating mainly happened in the range of 30--150℃ and 400--600℃. The former was associated with IER desorption, while the latter was related to thermal decomposition of IER and power coating. The static and dynamic adsorption curves of the modified desiccant coating indicated that adsorption performance was improved significantly after modification. Hygroscopic repeatability test demonstrated that the desiccant coating still had excellent stability for adsorption and desorption.