SU1268919A1 - Shaft furnace gas distribution arrangement - Google Patents

Abstract

The invention relates to the direct production of iron in shaft furnaces and can be used to evenly distribute the gas in a dense moving stream. The aim of the invention is to improve the uniformity of gas distribution in the furnace. The essence of the invention is to install upper rows of tuyeres, located 0.1-0.3 in radius of the furnace at an angle of 31-45 °, which allows for co-flow from downstream tuyeres and the distance between with tuyeres up to 0.6 M get a uniform gas distribution over the shaft section. 3 il.

Description

1HE

05 GS CO

The invention relates to the direct production of iron in shaft furnaces, but can be used in other areas of technology, for example, in preparing raw materials for metallurgical processing in layer furnaces, charge heaters and heat exchangers, where it is necessary to create a uniform distribution of gas in a dense moving layer. bulk material.

The aim of the invention is to improve the uniformity of gas distribution in the furnace.

FIG. 1 shows a shaft furnace for metallization with a diameter of up to 8 m with a tuyere gas distribution device, the collector of which is located outside the furnace, its general view; in fig. 2 shows an embodiment of a tuyere gas distributor of a device with one light-emitting alternating long and short tuyeres and with a collector embedded in the laying of the furnace; in fig. 3 shows an embodiment of a gas distribution device with two tuyere engages connected by a common collector.

The shaft furnace 1 consists of one or several zones, including the recovery zones 2 and the cooling zone 3. At the same time, a gas flow from zone 3 to zone 2 is possible. The tuyere device is located in the lower part of the recovery zone 2. It contains a gas supplying nozzle 4, an annular manifold 5 and long 6 and short 7 tuyeres pushed into the material layer. Moreover, the number of tuyeres of one level reaches the value, where R is the radius of the mine in meters.

The hot reducing gas flows through the nozzle 4 (or through several such nozzles) into the collector 5 and is distributed through the tuyeres 6 and 7 in the volume of the layer of material being processed and. lifting up, interacting with the material, after which it is removed from the furnace.

The choice of the parameters of the tuyere 1 distribution device should be made depending on the amount of tuyere gas, the size of the lump material being processed and the porosity of the layer. The optimum number of lances of one row of 6R-10s in a dense bed of a shaft furnace when gas is fed through lances with the same height. There is a significant uneven distribution of gas, having a minimum level at a height of lance equal to 0.3 of the shaft radius.

This non-uniformity can be reduced by 15-30% (both in the radial and in the angular directions) if the gas is supplied through tuyeres of various lengths, while the distance between the tuyeres is 0.6-1.0 m, which corresponds to the number above. I determine that the angle of inclination of the tuyeres is largely determined by the presence of a co-current gas flow, for example, a reducing gas supplied from the cooling zone to the recovery zone

ovens. In this case, the optimum angle of inclination of the tuyeres to the horizontal in the absence of a co-current flow is close to 45 ° (43 °).

The gas stream flowing from the tuyeres creates a material sealing front behind the loosening zone, which prevents the gas flow to the center of the furnace. The displacement of this front downward, which is achieved by the inclination of the tuyeres, creates more favorable conditions for gas distribution. At the same time, the optimum angle of inclination of the tuyere should be between 0 ° and 90 °, which corresponds to both the physics of the flow pattern and the average integral current line (its analysis). Experiments conducted on a cold model of a shaft furnace showed that when feeding, the installation was blown only through the tuyeres of the recovery zone (wake flow from the cooling zone is zero), the optimum slope of the tuyeres is 43 ° (Fig. 1). When co-current is supplied to the installation center, the distribution of the tuyere blowing in the axial part is not required, therefore the cross-sectional area of the furnace and the ring thickness (-th, where g is the radius of the circle in which the co-current propagates) in which the uniform gas distribution of the tuyere blowing also decreases, and the angle of inclination of the tuyeres, of course, also decreases. Experiments show (Fig. 1) that with a central confluent flow of 1 / 2-1 / 4 of the amount of reducing gas, the optimum value of the slope of the furm is approximately equal to 19 °.

The supply of the same amount of gas to the cooling zone, but through the peripheral input devices, results in a cocurrent that develops along the walls of the unit and pushes the reducing gas to the center of the furnace and, in addition, occupies part of the cross section. In this connection, the angle of inclination of the tuyeres, in this case, should be less than the angle of inclination in the absence of a co-current. However, this angle must be greater than the angle of inclination in the case of a central cocurrent, since with equal average speeds of movement in different parts of the cross section, the crowd of the ring in which the cocurre flow develops is less than in the previous case (R kiln where rn is the radius of the circle in which tuyere gas distribution is provided), and therefore the inlet to blow by means of inclined tuyeres should ensure uniform gas distribution over the radius of the furnace — gi.

The invention differs from the known gas distribution devices in shaft furnaces by the possibility of creating a more even distribution of the gas flow and better utilization of its energy potential in high-capacity furnaces, which allows the creation of large-scale production of metallized products of great national importance.

Claims (1)

Invention Formula Gas distribution device of the shaft furnace, containing, its tuyeres in the amount of 6R-10 /, where R is the radius of the furnace, installed with a high 0.1-0.3 radius of the furnace, characterized in that, in order to improve the gas distribution in the furnace, the tuyeres are installed obliquely at an angle of 31-45 ° to the horizontal plane unloading side. U8.f four § ; i: S: