Optinal Design And Temperature Field And Flow Field In Electromagnetic Cold Crucible Used For Solidifying Glass

Radioactive waste will be left after nuclear fuel reaction. Its radioactivity cannot beeliminated by any physical or chemical process but decay with half-life period ofradionuclide for more than hundreds of thousands of years. However, using coldcrucible to curing process nuclear waste and deeply burying solidified body couldprevent environment from the detriment of nuclear waste. Thus, it is significant forsafety disposing nuclear waste to study cold crucible curing technology.Established a sense of cold crucible electromagnetic3-D finite element model, theresults showed that: the magnetic field intensity of center-height location of crucible isin maximum value under idle condition and decrease progressively with altitudevariation. There is a growth of magnetic field intensity because of electric currentsuperimposed effect in slotting cut-off area. The magnetic field intensity is enhanced asthe current increases from500A to1500A, while it decreases when the frequency risesfrom50kHz to200kHz. However, the fluctuation of the magnetic field intensity isnot obvious between the slotting and in the center of crucible. The increasing of currentfrequency can enhance the heating efficiency of cold crucible and up to40%in200kHz.According to the research results of this research group, reference foreignliteratures and patents, and in line with high radioactive work environment of glasssolidification to work out water-cooling slide valve construction which can be freelycontrolled start and stop. Combine with technological requirements and regulations ofelectromagnetic field distribution, crucible is designed to be a cold crucible which ismade fromφ16mm stainless steel tube with360mm inner diameter,300mm height and30L effective volume. And working out relevant induction coil, the upper and lowerwater-cooled ring, water-cooled chassis and crucible cover.The internal flow of glass melt can be divided into two spiral circulation: up anddown. Liquid flow respectively flows from up and down sides near side surfaces of meltto middle, and then backflow to accomplish the circulation of flowing. The flowvelocity is faster with the increasing of current value and frequency. And with theincreasing of frequency, the maximum flow velocity area is transferring horizontal flow of up and down surfaces to vertical flow of side surfaces near melt.Calculated the distribution of temperature field of melt interior and analyzed thedistribution of temperature of different power parameter conditions. With the increasingof current value and frequency, heating time which in operating temperature will bereducing, but the temperature gradient will be enlarging which causes the distribution ofmelt interior uneven. Smelting process should be added mechanical agitation on thebasis of physical truth.