F-32-TR Fouling Evaluation of StreaMax™ Coating Using Desalted Crude Oil 28
This report presents the results of a test comparing the fouling performance of plain carbon steel tubes with tubes coated on the inside with StreaMax, a fluoropolymer, in thicknesses of 100 and 200 µm. In the test, desalted Crude 28 was recirculated for 30 days in the High Temperature Fouling Unit 2 (HTFU-2) flow loop. As anticipated, fouling (thermal resistance) was lower in the coated tubes than in the plain carbon steel tubes. However, it was not possible to ascertain which coating thickness yielded better performance because the rated maximum operating temperature of the coating (260 °C) limited the fouling potential of the crude. Baseline test results indicate that higher fouling trends may be observed at wall temperatures exceeding 260 °C. After the test, visual inspection showed no damage to the coated surfaces, and compared to the plain tubes, fouling deposits on the coated tubes were significantly easier to remove, requiring only a simple solvent rinse and no scraping. This could translate into maintenance savings, which, in some cases, could justify the cost of the coating application. Roughness assessments using a 3D optical profilometer indicated that the coated surfaces were rougher than those of plain carbon steel, with the 200-µm thick coating exhibiting approximately twice the roughness of the 100-µm thick version. Coatings appear to contribute to a reduction in pressure drop compared to the uncoated tubes. This report also discusses a procedure to measure coating thickness using a 3D optical profilometer, as well as a method to estimate the thermal conductivity of the coatings from experimental data.