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Show 5. CONCLUSIONS On the basis of the findings obtained by use of the model, there are some limitting condition to develop heat pattern in the bed. Herejt is clearly decided the critical humidity concentration in the suction gas. The effects of these factors on the reaction rates, the temperature distribution of the sinter bed and critical conditions for the flue gas recirculation can be quantatively evaluated by this mathematical model. In recirculating the waste gas, it causes high humidity content in the suction gas, so it will lead over the value(0.3kgH2O/kg),the ordinal temperature level can not be kept. It is semmed that high vapor existance decreases the coke combustion reaction. In addition, because recirculating waste gas decrease the partial pressure of oxygen in the gas, so the combustion reaction of coke will be decreased. Then it should be paid enough compensation for the high temperature gas. Concerning the layer pressure drop,here assumed maximum two times passing are allowed through packed bed. In the longitudinal direction, the machine divided to six zone in the calculating model. Then it combined the one zone's outlet gas is conducted to another zone's inlet gas and approximately 400 cases were tested by virtual simulation on the computer model. As a result, the waste gas recirculating method will increase the amount of moisture condensation in the sinter bed and decrease the maximum temperature in the bed For typical case,it divided in six zone, no.6 zone's outlet gas should leaded to no.1 zone's inlet gas, no.5 zone to no.2 and no.4 zone to no.3 zone. In this case ,the total exhaust gas can be minimized and the decreasing rate becomes approximately 33%. By this virtual simulation technics developed here, the optimum condition can be dicided cleared for every cases. 6. REFERENCES (1) J.Shibata,Y.Hosotani,N.Konno,T.Sato,H.Suzuki: I.S.I.J. International, Vol.35, No.1 ,1995,p.l340 (2) Y.Hosotani,N.Konno,J.Shibata,T.Sato,H.Suzuki: TestutoHagane,Vol.81,No.l, 1995, P.34 (3) J.Shibata,Y.Hosotani,N.Konno,Y.Tokunaga : Proceeding of the 17th International ATS Steelmaking Conference , Vol7.1996 , p.36 7. NOMENCLATURE Cco2: carbon dioxide concentration, Cg : specific heat of gas, Cs: specific heat of solid, |