An experimental study of the growth of scale on copper, nylon 6,6, semiaromatic high temperature nylon, polypropylene, polybutylene, and Teflon tubes exposed to hard water is presented. Results provide qualitative information on the scaling of polymer tubes in nonisothermal, flowing conditions expected in heat exchangers and solar absorbers. The 89-cm-long tubes were placed in tube-in-shell heat exchangers. The tubes were exposed to flowing water for 1660 h, a 1120-h pretreatment phase using tap water adjusted to supersaturation of about 2 and of 8, followed by a 540-h acceleration phase using tap water with an adjusted total calcium concentration of and a of 9. Flow rate was 4 cm/s. A 50% propylene glycol solution at was maintained on the shell side of the heat exchanger. Sections of the tubes were removed periodically to determine the extent of scaling. Results include scanning electron microscope images of the tube surfaces before and after exposure to the flowing water, x-ray diffraction to determine the crystalline phase content of the observed deposits, and chemical analysis to estimate the mass of calcium carbonate per unit surface area. A model of the scaling process is presented to help interpret the data. The data show conclusively that polymer tubes are prone to scaling. With the exception of nylon 6,6, the scaling rate on the polymers is about the same as that on copper. The nylon 6,6 substrate appears to enhance scaling. The enhancement is attributed to hydrolysis of the substrate.
Skip Nav Destination
Article navigation
February 2005
Technical Papers
Scaling in Polymer Tubes and Interpretation for Use in Solar Water Heating Systems
Yana Wang,
Yana Wang
University of Minnesota, 111 Church St., S.E., Minneapolis, MN 55455
Search for other works by this author on:
Lorraine Francis
Lorraine Francis
University of Minnesota, 111 Church St., S.E., Minneapolis, MN 55455
Search for other works by this author on:
Yana Wang
University of Minnesota, 111 Church St., S.E., Minneapolis, MN 55455
Jane Davidson
Lorraine Francis
University of Minnesota, 111 Church St., S.E., Minneapolis, MN 55455
Contributed by the Solar Energy division of THE AMERICAL SOCIETY OF MECHANICAL ENGINEERS for publication in the ASME JOURNAL OF SOLAR ENERGY ENGINEERING. Manuscript received by the ASME Solar Energy Division May 17, 2004; for final revision June 22, 2004. Associate Technical Editor: A. Steinfeld.
J. Sol. Energy Eng. Feb 2005, 127(1): 3-14 (12 pages)
Published Online: February 7, 2005
Article history
Received:
May 17, 2004
Revised:
June 22, 2004
Online:
February 7, 2005
Citation
Wang , Y., Davidson, J., and Francis, L. (February 7, 2005). "Scaling in Polymer Tubes and Interpretation for Use in Solar Water Heating Systems ." ASME. J. Sol. Energy Eng. February 2005; 127(1): 3–14. https://doi.org/10.1115/1.1823492
Download citation file:
Get Email Alerts
Analysis of Erosion of Surfaces in Falling Particle Concentrating Solar Power
J. Sol. Energy Eng (April 2025)
Related Articles
A Review of Polymer Materials for Solar Water Heating Systems
J. Sol. Energy Eng (May,2000)
Polymers for Solar Domestic Hot Water: Long-Term Performance of PB and Nylon 6,6 Tubing in Hot Water
J. Sol. Energy Eng (February,2004)
Thermal Analysis of Polymer Heat Exchangers for Solar Water Heating: A Case Study
J. Sol. Energy Eng (May,2000)
Thermal Performance of a Large Low Flow Solar Heating System With a Highly Thermally Stratified Tank
J. Sol. Energy Eng (February,2005)
Related Proceedings Papers
Related Chapters
Engineering and Physical Modeling of Power Plant Cooling Systems
Thermal Power Plant Cooling: Context and Engineering
Chitosan-Based Drug Delivery Systems
Chitosan and Its Derivatives as Promising Drug Delivery Carriers
Sources of Chitosan
Chitosan and Its Derivatives as Promising Drug Delivery Carriers