Decontamination of Radionuclides from Concrete by Microwave Heating. II: Computations
نویسنده
چکیده
Based on a mathematical model developed in the preceding Part I of this study, a numerical analysis of the process of decontamination of radionuclides from concrete by microwave heating is conducted. The aim is to determine the required microwave power and predict whether and when the contaminated surface layer of concrete spalls off. As customary, the finite element method is used for the stress and fracture analysis. However, as a departure from previous studies, the finite volume method is adopted to treat the heat and moisture transfer, in order to prevent spurious numerical oscillations that plagued the finite element response at moving sharp interface between the saturated and unsaturated concrete, and to deal accurately with the jumps in permeability and in sorption isotherm slope across the interface. The effects of wall thickness, reinforcing bars, microwave frequency, and power are studied numerically. As a byproduct of this analysis, the mechanism of spalling of rapidly heated concrete is clarified. DOI: 10.1061/~ASCE!0733-9399~2003!129:7~785! CE Database subject headings: Computation; Concrete; Microwaves; Contamination; Contaminants; Heating; Diffusion; Thermal stresses; Pore pressure.
منابع مشابه
Decontamination of Radionuclides from Concrete by Microwave Heating. I: Theory
The paper analyzes a proposed scheme of decontamination of radionuclides from concrete structures, in which rapid microwave heating is used to spall off a thin contaminated surface layer. The analysis is split in two parts: ~1! the hygrothermal part of the problem, which consists in calculating the evolution of the temperature and pore pressure fields, and ~2! the fracturing part, which consist...
متن کاملProject Title : Decontamination of Radionuclides from Concrete During and After Thermal Treatment
متن کامل
Mobile Asbestos Decontamination by Microwave Hybrid Heating
Within the European project "New Safe and Cost Effective Techniques Against Asbestos Risks" different methods for decontamination of asbestos in asbestos containing wastes, abbreviated as ACW from building industry were investigated. A mobile asbestos decontamination unit was developed, aiming at the complete disintegration of asbestos fibres on-site. The process is based on a chemo-thermal tre...
متن کاملA comparative study of infrared and microwave heating for microbial decontamination of paprika powder
There is currently a need in developing new decontamination technologies for spices due to limitations of existing technologies, mainly regarding their effects on spices' sensory quality. In the search of new decontamination solutions, it is of interest to compare different technologies, to provide the industry with knowledge for taking decisions concerning appropriate decontamination technolog...
متن کاملThermal Stresses in the Microwave Heating of Concrete
The significance of compressive thermal stresses generated during microwave heating on concrete surface delamination is investigated analytically in this paper. Microwave energy acts as an internal heating source that causes concrete to heat up. The amount of microwave energy dissipated in concrete depends on microwave frequency, microwave power and the electromagnetic properties of the concret...
متن کامل