TWI580790B - Blast furnace blast system - Google Patents

Description

Blast furnace blast system

The present invention relates to an ironmaking system, and more particularly to a blast furnace blasting system.

In recent years, with the rise of environmental awareness, all walks of life have been actively saving energy and reducing carbon. For the ironmaking industry, the purified blast furnace top gas (BFG) and coke or pulverized coal are blown into the wind tunnel of the blast furnace via a spray gun and a blast tube. Combustion in (raceway) is considered to be an important method to reduce CO2 emissions from the blast furnace ironmaking process.

The main purpose is to utilize the higher concentration of hydrogen and carbon monoxide contained in the top gas of the purified blast furnace, not only to generate heat and reducing gas required for iron making in the wind tunnel region, but also to replace the consumption of some high-priced coke. Thereby reducing the amount of carbon dioxide emissions.

However, due to the flammability of hydrogen and carbon monoxide contained in the top gas of the blast furnace, as long as the blast furnace top gas is sprayed into the blast pipe through the spray gun, it will immediately blast with the hot air in the blast pipe ( Hot blast) Oxygen reaction combustion, which causes coke or pulverized coal to crack and burn ahead of the blast tube, resulting in increased pressure loss of the blast tube, which affects the size of the wind tunnel. If the wind tunnel area is too large, the blowing phenomenon will occur. On the contrary, if the wind path area is too small, the center accumulation phenomenon will occur, and the stability of the iron making process will be unfavorable whether it is over-blowing or central accumulation.

Therefore, how to control the pressure loss of the blast tube and the size of the wind tunnel area to improve the stability of the iron making process has become a problem that the relevant industry desires to improve.

Accordingly, it is an object of the present invention to provide an blast system for a blast furnace which can stabilize pressure loss and improve the stability of the iron making process.

Thus, the blast system of the blast furnace of the present invention comprises at least one blast unit. The air blowing unit has a blast pipe, a blaster that communicates with the blast pipe and extends into the blast furnace, and a lance mechanism that extends into the blast pipe, and the blasting nozzle satisfies the following formula:

Where Δ P _t is the pressure loss of the air outlet of the air blowing nozzle, f is the friction factor, L _t is the length of the air blowing nozzle into the blast furnace, D _t is the diameter of the air blowing nozzle, and L _R is the air diameter Area depth.

The beneficial effects of the invention are: in the case that the blast furnace top gas early combustion cannot be avoided, the utilization equation is satisfied: The blaster mouth adjusts the length of the blaster into the blast furnace and the diameter of the blaster to maintain the pressure loss without affecting the depth of the wind tunnel, and can improve the stability of the iron making process.

2‧‧‧Blowing unit

200‧‧‧ blast furnace

21‧‧‧Blowing tube

22‧‧‧ blaster

23‧‧‧ spray gun mechanism

Other features and advantages of the present invention will be apparent from the embodiments of the present invention, wherein: FIG. 1 is a schematic diagram illustrating a preferred embodiment of the blast furnace blast furnace system of the present invention; FIGS. Comparing the figures, the relationship between the penetration factor of the preferred embodiment and the wind-diameter zone factor is illustrated; FIG. 4 is a schematic diagram illustrating the dimensional conditions of the blaster nozzle and the wind-diameter zone for performing the simulation experiment; and FIG. 5 is a comparison diagram. The relationship between the pressure loss of the air outlet of the air blowing nozzle and the length of the air blowing nozzle into the blast furnace, and the diameter of the air blowing nozzle.

Referring to Figure 1, a preferred embodiment of the blast system of the blast furnace of the present invention comprises a plurality of blower units 2. Each of the air blowing units 2 has a blast tube 21, a blast nozzle 22 that communicates with the blast tube 21 and extends into the blast furnace 200, and a lance mechanism 23 that projects into the blast tube 21. Since the structure of the air blowing unit 2 is the same, only one air blowing unit 2 will be described in FIG.

In the preferred embodiment, the lance mechanism 23 of the air blowing unit 2 is an asymmetric double air-cooled coaxial spray gun capable of simultaneously ejecting blast furnace top gas and pulverized coal from the blast nozzle 22 (double air -cooled coaxial lance), and the asymmetric double air-cooled coaxial spray gun is inserted into the blast tube 21 in an eccentric manner as shown in FIG. 1. Of course, in practical application, the air blower unit 2 has a spray gun The mechanism 23 can also be a projecting spray gun, and the same effect can still be achieved.

The inventor conducted a simulation experiment of the blast system of the blast furnace as shown in Fig. 1 to obtain the Penetration Factor (P _F ) and the wind diameter zone factor of the blast system as shown in Figs. The relationship diagram of Raceway Factor, R _F ), and regression analysis to obtain the relationship between the depth of the wind tunnel (shown as the imaginary line in Figure 1) and the kinetic energy of the blast.

Where the penetration factor is And the wind diameter zone factor is 0.5 / ρ _s gd _p , L _R is the depth of the wind tunnel, D _t is the diameter of the blast nozzle 22, ρ is the gas density, V _ave is the gas velocity, ρ _s is the particle density, g is the gravity acceleration map, d _p Is the particle diameter.

Since the wind-span zone factor is proportional to the square of the velocity, the P _F -R _F curve regressed by the quasi-two-dimensional model in Fig. 2 is about 1.2 times the velocity in the acceleration segment, and about 0.8 in the deceleration segment. The speed of the 1.6th power; Figure 3 is a three-dimensional model of the P _F -R _F curve, both in the acceleration section and the deceleration section are proportional to the speed of the first power. As can be seen from the above, the depth of the wind-diameter region is proportional to the diameter of the blast nozzle 22, and the relationship with the speed is 1 to 1.6, that is, .

According to the Moody Chart, the pressure loss of the air outlet of the air blowing nozzle 22 is proportional to the length of the air blowing nozzle 22 extending into the blast furnace 200, and the fluid kinetic energy, and the air blowing nozzle 22 The caliber is inversely proportional, ie .

Where Δ P _t is the pressure loss of the air outlet of the air blowing nozzle 22, f is the friction factor, L _t is the length of the air blowing nozzle 22 extending into the blast furnace 200, and D _t is the diameter of the air blowing nozzle 22, Fluid kinetic energy.

Without prejudice to the depth of the wind tunnel (ie maintaining the same blast kinetic energy), versus Two styles, pushed And when the friction factor ( f ) is the same as the wind path depth ( L _R ), the above equation can be simplified to That is, the pressure loss (Δ P _t ) of the air outlet of the air blowing nozzle 22 is proportional to the length ( L _t ) of the air blowing nozzle 22 extending into the blast furnace 200, and the diameter of the air blowing nozzle 22 ( D _t ) is inversely proportional to the 2.25~3 power.

Referring to Figures 4 and 5, in order to verify the effect of the present invention, the inventors, as shown in Figure 4, have a predetermined wind-diameter zone depth of 950 mm, and the length ( L _t ) of the blast furnace 200 is 405 mm and 470 mm, respectively, and the diameter ( D) _t ) Simulation experiments were carried out on the blast nozzles 22 of 120 mm, 130 mm and 135 mm, respectively, and the results are shown in Fig. 5.

As can be seen from Fig. 5, in the case of the same length, the increase of the diameter ( D _t ) can actually reduce the pressure loss of the air outlet of the air blowing nozzle 22; and in the case of the same aperture ( D _t ), the length ( L _t ) is shortened. The pressure loss (Δ P _t ) of the air outlet of the air blowing nozzle 22 can also be reduced, and the influence of the diameter ( D _t ) is greater than the length ( L ) for the pressure loss (Δ P _t ) of the air outlet of the air blowing nozzle 22 _t ) the impact.

In summary, the blast system of the blast furnace of the present invention utilizes the satisfaction equation in the case where the blast furnace top gas cannot be prevented from being prematurely burned: The blaster 22 adjusts the length of the blast furnace 22 into the blast furnace 200 and the diameter of the blast nozzle 22 to maintain the pressure loss without affecting the depth of the wind tunnel region, and can improve the iron making process. The stability of the invention is indeed achieved by the object of the present invention.

However, the above is only the preferred embodiment of the present invention. The scope of the present invention is not limited thereto, that is, the simple equivalent changes and modifications made by the present invention in the scope of the invention and the scope of the patent specification are still within the scope of the invention.

2‧‧‧Blowing unit

200‧‧‧ blast furnace

21‧‧‧Blowing tube

22‧‧‧ blaster

23‧‧‧ spray gun mechanism

Claims (4)

An blast system of a blast furnace, comprising: at least one blast unit, having a blast tube, a blast nozzle connecting the blast tube and extending into the blast furnace, and a lance mechanism extending into the blast tube The blaster meets the following formula: Where Δ P _t is the pressure loss of the air outlet of the air blowing nozzle, f is the friction factor, L _t is the length of the air blowing nozzle into the blast furnace, D _t is the diameter of the air blowing nozzle, and L _R is the air diameter Area depth. The blast system of the blast furnace according to claim 1, wherein the blasting mechanism of the blast unit simultaneously ejects blast furnace top gas and pulverized coal from the blast nozzle. The blast furnace blast furnace system of claim 1, wherein the blasting unit of the blast unit is an asymmetric dual air cooled coaxial lance. The blast system of the blast furnace according to claim 1, comprising a plurality of air blowing units.