Patent UA-99394-C2 (UA)
Title: Method for comprehensive utilization of heat of vessel gases with producing of hot and cold soft-burned lime and hot water
Inventor: IVANETS VALERII HRYHOROVYCH
IPC: C21C5/28
Filed: 2011-05-17
Abstract: The invention relates to ferrous metallurgy, in particular to a method for production of steel in vessels using oxygen blowing and with comprehensive utilization of heat of vessel gases. A method comprises the supply of limestone as calcium-containing material having size more than 8 mm, introduction of annealed lime into vessel under heated to temperature 700-1200 ºC condition, complete afterburning of hot vessel gases, which are formed at blowing of steel by oxygen, cooling of hot vessel gases formed after their complete afterburning due to mixing with induced air which is supplied in amount providing temperature of producing of gas mix in range 1250-1350 ºC, cooling of vessel gases formed after dilution by induced air due to annealing of limestone to temperature 820-850 ºC and additional producing of cold soft-annealed lime for realization on side with its cooling with air to temperature not more than 50 ºC, packaging cooled soft-annealed lime in container from moistureproof material, finishing cooling of vessel gases formed after annealing of limestone in heat exchange device, preheating, dehydration, heating and decarbonation of limestone and also heating of freshly-annealed lime, increase of rate removal of annealed material of fine-grained fraction formed again in pores from heating zone of freshly-annealed lime through zones of decarbonation, heating and dehydration to preheating zone of annealed limestone at moving of hot vessel gases bottom-up through layer of annealed lime and annealed limestone, regulation of consumption and temperature of hot vessel gases, formed at their afterburning and dilution with induced air due change of underpressure in zone of draw air using smoke exhauster with frequency-regulated electro engine rate, preheating, dehydration and partial heating of limestone by heat of hot vessel gases which are formed before and after blowing of steel with oxygen, supply of limestone in zone for annealing portions of given volume during total time of steel melting in amount providing the cooling of hot vessel gases formed after their complete annealing and mixing with induced air to temperature 820-850 ºC with removal of dust, unloading formed soft-annealed lime from annealing zone portion/portions of given volume only at time of lime supply in steel melting process, at that air on cooling to temperature not more than 50 ºC of made for realization on side of soft-annealed lime is supplied in amount providing producing of exhaust hot air with temperature which not exceeding 350 ºC, exhaust hot air with temperature not exceeding 350 ºC is mixed with cooled vessel gases formed due to additional producing of cold and soft-annealed lime and are directed on finishing cooling of vessel gases in heat exchangers device, for example in water-heating boilers. The invention provides the increase of efficient process of steel melting by decrease its cost due to utilization of low-temperature heat of vessel gases.