Mitigation of CaCO3 fouling on heat exchanger surface using green functionalized carbon nanotubes (GFCNT) coating

• Published in: Thermal science and engineering progress Vol. 42; p. 101878
• Main Authors: Shaikh, Kaleemullah, Kazi, Salim Newaz, Mohd Zubir, Mohd Nashrul, Wong, KokHoe, Binti Mohd Yusoff, Syamimi Aisyah, Ahmed Khan, Wajahat, Shadab Alam, Md, Abdullah, Shekh, Bin Muhd Shukri, Muhd Hakimie
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2023
• Subjects: Calcium Carbonate; Carbon Nanotube Coating Layer; Electrophoresis; Fouling Resistance; Gum Arabic; Overall Heat Transfer Co-efficient; Overall Heat Transfer Co-efficient; Electrophoresis; Calcium Carbonate; Fouling Resistance; Gum Arabic; Carbon Nanotube Coating Layer
• ISSN: 2451-9049; 2451-9049
• DOI: 10.1016/j.tsep.2023.101878

•SS316L test section surface was coated with green functionalized carbon nanotubes.•Electrophoresis method was used to develop a coating layer on the SS316L surface.•The coated and uncoated specimen was investigated in test rig.•Fouling resistance and heat transfer performance was evaluated.•Coated surface reduced the fouling resistance and increased the heat transfer. Deposition of mineral foulants on the heat exchanger surface increases the thermal resistance and shortens the operating service life of heat exchangers. The inverse solubility characteristics of some mineral salts in the cooling water cause intensive mineral fouling on heated heat exchanger surfaces. The formation of fouling deposits starts when mineral salts in water crystallize on the heated surface. In this study, a coating of MWCNT from the suspension of water, gum Arabic and MWCNT was applied on the surface of the heat exchanger to mitigate CaCO3 fouling. A 300 mgL−1 CaCO3 supersaturated solution was prepared and used for the foulant deposition on the heat transfer surfaces and analysis. The Field Emission Scanning Electron Microscopy (FESEM) was used for the investigation of CaCO3 depositions on the heat exchanger surface, its surface morphology, and develop correlation with the crystal growth, morphology and the coating introduced inhibition effect on fouling. The results revealed that the CaCO3 crystal formation can be considerably retarded using MWCNT coating layer as a fouling mitigation approach.