Author(s): Steven F. Daly; F. Donald Haynes; Donald Garfield; John J. Gagnon
Linked Author(s): Steven F. Daly
Keywords: No Keywords
Abstract: The freezeup of water intake trash racks is a common and severe problem in northern areas during the winter. Heating of the trash racks is one solution; however, the amount of energy required to hear a trash rack is large and not economically viable in most instances. There have been no systematic studies of heated trash racks under frazil ice conditions, so a heated, model intake trash rack was observed in the refrigerated flume facility at USA CRREL, Hanover, NH, USA. Supercooled water and frazil ice were generated in this facility and allowed to pass through the model trash rack. In each test a near constant upstream head was maintained and the discharge through the trash rack was allowed to vary. A novel and efficient means of applying heat is described. The heat transfer rate from the rack was measured and is described in terms of nondimensional parameters. The discharge rates through the rack as a function of time and heat application rate are described. Based on these observations, an approach to quantify the design of heated trash racks is proposed.
Year: 1990