APPLICATION OF ELECTRICAL ENERGY TO CULVERT ICING PROBLEMS. A LABORATORY STUDY.
A laboratory study was made to investigate the use of electric heat cables to counteract culvert icing. An automatic system for producing a thaw tunnel of a preselected diameter was developed and tested. An 80-in.-long, 1-ft-diam culvert with a 10-ft copper sheath heating cable modeled a typical Alaskan installation. Tests were made to evaluate several continuous power levels, a short-term percentage timer, and the automatic system. Maximum efficiency (cross section produced/unit energy input) occurred when the cable was operated continuously at its maximum permissible power level. The short-term timer system was less efficient than applying the same amount of energy continously. The automatic system performed well in the laboratory, but may need additional design work to ensure high reliability in field applications. Observations indicate that the major heat transfer mechanism is convection. Marked constrictions in tunnel size were observed at the ice/air interfaces. These observations imply that the cable should be installed near the bottom of the culcert and the end risers doubled or tripled. The relative cost comparison among the three modes of heat cable operation indicated that the continuous operation mode is the most reliable, but the most expensive. The pulsed system was less expensive. The automatic system was the least expensive, within the constraints of the comparison. Six recommendations are made for further studies based upon the experience gained from field studies and the results of the laboratory study.
- Performed in Cooperation with: State of Alaska, Department of Highways and U.S. Department of Transportation, Federal Highway Administration.
Hanover, NH USA 03755-1290
- Gaskin, D A
- Stanley, L E
- Publication Date: 1974-3
- Features: Appendices; Figures; References; Tables;
- Pagination: 43 p.
- TRT Terms: Copper; Culverts; Electric cables; Heat transfer; Icing; Laboratory tests
- Old TRIS Terms: Polarographic analysis
- Subject Areas: Bridges and other structures; Highways; Maintenance and Preservation;
- Accession Number: 00262981
- Record Type: Publication
- Report/Paper Numbers: Tech Rept 248
- Files: TRIS
- Created Date: Nov 12 1974 12:00AM