SU954427A1 - Method for melting steel in two-bath furnace - Google Patents

Description

The invention relates to ferrous metallurgy, in particular to steel smelting in twin - bath furnaces operating with cold chamber heating.

A known method of steelmaking in a two-bath furnace is that during the period of charging and heating of the charge, flue gases from the blown (hot) chamber are withdrawn into the cold chamber and additionally supply fuel and oxygen for its combustion. The heat load per ton of the charge is 51102 thousand kcal / t.ch, the oxygen consumption in the filling is 15.6. Hours, the scrap filling speed is 180-280 tons / h, the blowing intensity is 18-28. The disadvantages of this method are a decrease in the heating efficiency of the cold chamber. during loading with the simultaneous supply of flue gases and FUEL torch. Flue gases reduce the overall heat transfer coefficient .-.

In addition, the removal of flue gases into the cold chamber during the loading period leads to the dislodging of a significant amount of combustion products from the furnace windows, gas pollution and dusting of the workshop atmosphere.

. The purpose of the invention is to increase the efficiency of the furnace and improve working conditions.

The goal is achieved by the fact that in the well-known method of steelmaking in a two-bath furnace, including the supply of flue gases from the chamber, blowing into the cold chamber, filling up scrap at a speed of at least 100 t / h, heating

10 with a heat load of more than 60000 kcal / h, melting and finishing with the blowing of a metal bath with oxygen, afterburning of carbon monoxide in the working space of the furnace, during the filling of scrap metal, the flue gases 15 from the blown chamber are discharged into the smoke path adjacent to it.

Afterburning of carbon monoxide is carried out in a purged chamber.

The method is carried out as follows.

After melting, the bath is charged. During this period, its heating is carried out through the burners (stationary vault, pinch movable or end). During the period of filling charge materials with a speed of 100,400 t / h, the thermal capacity of the flare heating of the cold chamber is set within 60-200 thousand kcal / t-h,

Claims (2)

30a, the flue gases from the purge chamber are removed to the smoke tract adjacent to it. After the end of the filling, a change in the smoke exhaust is made. Now he is from the cysts from the blown chamber into the cold chamber. In this case, it is advisable to reduce the thermal power of the flare heating until the fuel supply is completely cut off. At the end of the cast iron, begin a mild swelling of the bath with oxygen and stop its heating. After the discharge of the cast iron, the flow rate of purge oxygen is increased to a maximum. The intensity of the oxygen purge is 15-80. At the same time, the fusion is released from the second chamber and its filling is started. From the beginning of the filling of the cold chamber, oxygen (air, products of combustion with an excess of oxygen) is fed into the blown chamber above the bath for the afterburning of carbon monoxide. The supply of oxygen for the afterburning can be carried out through one of the blowing tuyeres, when installed in the cad with a purged metadl so that the streams reach the ground, spread along it, burn the carbon monoxide directly but above it. Removal of flue gases from the purge chamber during the filling of the cold chamber into the smoke path creates favorable conditions in the cold chamber for heat transfer from the combustion flame to the charge by increasing the coefficient of heat transfer directions from the torch and participation in heat transfer of the masonry of the working space. The advantage of the proposed method is an increase in the efficiency of scrap heating during the filling period and in connection with this an increase in the scrap fraction in the process and an improvement in working conditions due to a sharp decrease in the dust content of the workshop. The afterburning of carbon monoxide over a blown bath makes it possible to further increase the efficiency of the process in thermal work and to reduce the loss of metal with oxides of ox and korolka. 1. Method of steel melting in a two-bath furnace, including the supply of flue gases from the purge chamber to the cold chamber, filling of scrap with a speed of at least 100 t / h, heating with a heat load of more than 60,000 kcal / h, melting and finishing with bath blowing metal with oxygen, afterburning of carbon monoxide in the working space of the furnace, distinguished by the fact that, in order to increase the efficiency of the furnace and improve working conditions, during the supply of scrap, flue gases from the purge chamber are diverted to the smoke path adjacent to it 2. A method according to claim 1, characterized in that the post-combustion of carbon monoxide is carried out in a purgeable chamber. Sources of information taken into account during the examination 1. Metallurgists. Bulletin. scientific and technical information, 9. Central Research Institute of Information and Technical and Economic Research of Ferrous Metallurgy, 1976, p. 42-45 (prototype).