JPS63171815A - Oxygen blast furnace - Google Patents

Abstract

PURPOSE:To lighten a preheating gas blowing device and to quickly keep up with variety of the furnace condition, by arranging plural pieces of burners having fuel gas supplying pipe, oxygen supplying pipe and gas introducing pipe for controlling gas temp. at a shaft part. CONSTITUTION:The preheating gas blowing device from the shaft part is composed of plural pieces of the burner body 8 having the fuel gas supplying pipe 1, oxygen supplying pipe 2 and gas introducing pipe 5 for controlling gas temp. and pilot burner 9 is arranged at the position of injecting hole of oxygen. Further, supplying water tube 3 and discharging water tube 4 for cooling water are arranged in the burner body 8 and in case of using 100 for the height from stock line to the tuyere, the gas burner body 8 is set at the position of about 40 from the upper part. In this way, the preheating gas blowing device providing the burner having comparatively simple construction is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial Field of Application) This invention relates to the structure of a blast furnace for iron-making, particularly an oxygen blast furnace.

(Prior art) Conventionally, in the so-called blast furnace operation method for producing pig iron from ore, although some oxygen enrichment is carried out, when it comes to practical blast furnaces with high productivity, almost all of the high-temperature oxygen is Mainly uses air blowing.

In this case, N2, which accounts for about 79% of the air, does not directly participate in the reduction of iron ore, but it provides a huge amount of sensible heat to the charge from the tuyere tip to the stock line, which is necessary for active gas reduction. Since it played a role of heat reinforcement, there was no need to supply heat from other sources than the siding.
In addition to adding top gas, steam, etc. from the siding or near the tuyere to control the temperature rise at the tuyere tip, Nz
02 concentration is 40% due to the narrowing of the gas reduction area above 700℃ due to the decrease in gas volume due to the absence of gas, and the decrease in the temperature at the top of the furnace.
In the case of the above gas blowing, heat supply from the shaft part is required. For example, Japanese Unexamined Patent Publication No. 159104/1988 discloses that a part of the furnace top gas is separated, combusted, and blown into the furnace through a shaft.

FIG. 1 of this publication states that a combustion furnace is required around the blast furnace to generate high-temperature preheated gas using furnace top gas and oxygen.

However, in order to uniformly blow high-temperature preheated gas into the furnace from the furnace periphery, it is necessary to raise the hot air conduit up to the shaft and install a fairly heavy annular pipe. It is necessary to connect the nozzle to the rotary nozzle, and there are many unresolved problems such as unstable weight, increased initial cost, and heat retention measures.

(Problems to be Solved by the Invention) The present invention was devised in view of the current state of oxygen blast furnaces as described above, and is an oxygen blast furnace equipped with a burner of a relatively simple structure without lifting heavy objects to the shaft. The purpose is to provide blast furnaces.

"Structure of the Invention" (Means for Solving the Problems) In order to achieve the object of the previous section, the present inventors have developed a fuel gas supply conduit,
An oxygen blast furnace characterized in that a plurality of gas burners each having an oxygen supply conduit and a gas temperature control gas conduit are provided in a shaft portion.

Providing such a burner on the shaft not only eliminates the need to install a hot air annular tube, but also has the advantage of allowing free adjustment of gas temperature and gas amount for each burner.

(Function) In the present invention, an oxygen blast furnace refers to an oxygen concentration of 40% from the surface.
This is a blast furnace that operates by blowing the above gases at room temperature and by blowing preheated gas through a shaft.

The key points in the development were to be able to adjust the temperature of the preheated gas blown in from the shaft and the amount of air blown for each nozzle, and to avoid the need for a large-scale hot air annular pipe, so it was decided to install a burner in each nozzle. For burners,
There is an advantage that the transfer piping until combustion is carried out at room temperature.

(Example) FIG. 1 is a schematic longitudinal sectional view of a burner used in the present invention. The flow rate of both the fuel gas supply conduit 1 and the oxygen supply conduit 2 can be freely controlled, and the pyro and burner 9 connected to the burner main body 8 are connected to the gas supply conduit 1 and the oxygen supply conduit 2.
It is installed at the oxygen outlet. The outside of the burner body is covered with an iron skin 7. Further, a gas conduit 5 for adjusting the gas temperature of the gas generated by the gas burner is also connected, so that the temperature can be freely controlled. Cooling water conduits are shown as a water supply pipe 3 and a drain pipe 4. A gas burner was installed at a position of 40 from the top, with the distance from the stock line to the tuyere being 100.

FIG. 2 is a schematic vertical cross-sectional view of the blast furnace of the present invention, which is fixed to the shaft portion at an angle greater than the angle of repose of the blast furnace charge. From the oxygen tuyere 10, in addition to oxygen, there is a tuyere tip temperature adjusting gas,
Pulverized coal, steam, etc. are blown into it. Twelve burners were fixed to the shaft and the operation was carried out. Furnace top gas was used as fuel gas.

"Effects of the Invention" Unlike hot air supplied from a large gas combustion device common to each nozzle, the temperature and blowing amount for each nozzle can be freely and easily adjusted. There is no need for a heavy hot air annular tube around the furnace periphery, and it is possible to quickly respond to changes in furnace conditions.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal cross-sectional view of a burner used in the present invention, and FIG. 2 is a schematic vertical cross-sectional view of the blast furnace of the present invention. 1: Fuel gas supply pipe 2: Oxygen supply pipe 3: Water supply pipe 4: Drain pipe 5: Gas temperature adjustment gas pipe 6: Refractory 7: Iron shell 8: Burner body 9: Pilot burner 10: Oxygen lining

Claims (1)

[Claims] An oxygen blast furnace characterized in that a plurality of gas burners each having a fuel gas supply conduit, an oxygen supply conduit, and a gas temperature control gas conduit are provided in the shaft portion as a preheating gas injection device from the shaft.