©　2015　Pushpa　Publishing　House,　Allahabad,　India　The　basic　objective,　which　led　to　the　presented　models,　was　to　obtain　highest　possible　package　degrees　in　packed　beds　with　spherical　particles.　The　method　is　to　choose　particles　with　substantially　different　diameters,　e.g.,　by　applying　micro　or　nano　fillers　at　the　lower　end　of　the　diameter　spectrum.　The　developed　models,　in　the　limit　of　an　infinite　number　of　particle　generations　N,　lead　to　descriptions　of　fractal　geometrical　nature.　The　package　degree,　the　effective　specific　thermal　capacity　and　the　effective　thermal　conductivity　are　modeled　in　detail.　The　main　result　of　this　work　is　the　Fractal　Conductivity　Model　(FCM),　which　is　a　self-similar　continuation　of　the　Maxwell-Eucken　Model　(MEM),　the　Improved　Maxwell　Model　(IMM)　and　the　Gonzo　Model　(GM).　The　results　illustrate　that　the　FCM　for　low　N,　where　experimental　data　exist,　agrees　well　and　can　be　applied　to　numerically　simulate　the　effective　thermal　conductivity,　Keff,　for　1　＜　N　＜　∞.