ABSTRACT

Metals are common construction materials for heat exchangers. However, metals may suffer from failure due to corrosion, especially in harsh environments. Innovative thermally conductive polymer composite tubes based on polypropylene or polyphenylene sulphide filled with graphite have been developed. Crystallization fouling on metal surfaces has been extensively studied. However, fouling data for polymer surfaces are very limited. In the current study, a stirred vessel test rig and a horizontal tube falling film test rig were used to compare the fouling propensity of the polymer composite tubes and common stainless steel tubes. Experiments were performed with calcium sulphate solutions and mixed salt solutions containing calcium carbonate and calcium sulphate. The induction periods and the fouling resistances over time were measured. The novel polymer composite tubes showed a lower crystallization fouling propensity compared to the stainless steel tubes. The induction period was longer and the reduction of the overall heat transfer coefficient over time was notably lower compared to the metal tubes.

摘要

金属是热交换器的常见结构材料。然而，金属可能会因腐蚀而失效，尤其是在恶劣的环境中。已开发出基于聚丙烯或聚苯硫醚填充石墨的创新型导热聚合物复合管。金属表面的结晶结垢已被广泛研究。然而，聚合物表面的污垢数据非常有限。在目前的研究中，使用搅拌容器试验台和水平管降膜试验台来比较聚合物复合管和普通不锈钢管的结垢倾向。用硫酸钙溶液和含有碳酸钙和硫酸钙的混合盐溶液进行实验。随时间测量诱导期和结垢阻力。与不锈钢管相比，新型聚合物复合管显示出较低的结晶结垢倾向。与金属管相比，诱导期更长，总传热系数随时间的降低显着降低。