Page - 21 - in Adaptive and Intelligent Temperature Control of Microwave Heating Systems with Multiple Sources

2.2. StructureofHEPHAISTOS log f ε'' e 7 8 9 10 ε'' σd ωε0 2.45 GHz915 MHz Figure2.4. Effective loss factor due to the dipole relaxation and the ionic con- duction losses [Met96]. 2.2. StructureofHEPHAISTOS HEPHAISTOS is a giant microwave heating system equipped with spatially distributed feeding sources (see figure 2.5). The size of a standard HEPHAISTOS module is about 180 cm×155 cm×110 cm, which is comparable to large industrial autoclaves (such as in figure 2.5b) and much larger than other microwave heating systems used anywhere else [lar]. More important, multiple HEPHAISTOS mod- ules can be integrated into one large heating system, which is flexible todealwith large-scaleworkpieces. Compared with other microwave heating systems, HEPHAISTOS is much more complex. It not only has a complicated hardware structure, but also consists of a sophisticated process control system and combined temperature measurement techniques. In general, the wholeHEPHAISTOSsystemcanbedividedintothreeparts, indicated bythreedifferentcolors infigure 2.6. Thesethreepartsareintroduced in the followingof thischapter. 21