JPS62142707A - Method for blowing granular particle into blast furnace - Google Patents

Abstract

PURPOSE:To easily adjust the distribution of heat and gas in a furnace by respectively discharging granular particles and liquid independently through respectively separate pipes of a lance for blowing consisting of multiple pipes, mixing the granular particles and liquid at the top end of the lance and blowing the mixture in the form of a slurry into the furnace. CONSTITUTION:The lance 5 for blowing is constituted of double pipes consisting of the inside pipe 5a and the outside pipe 5b coaxially disposed to the outside thereof. The inside pipe 5a is connected to a granular particle supply pipe 7 via a shut off valve 8 and discharges the granular particles 11. The outside pipe 5b discharges water or oil 12 via a shut off valve 10. The top end of the inside pipe 5a is made shorter than the top end of the outside pipe 5b and therefore, the granular particles 11 and the liquid 12 are efficiently mixed to form the uniform slurry 13. The slurry 13 is blown together with hot air from a blow pipe 4 into the furnace through the tuyere 3 thereof.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention enables rapid changes in slurry flow rate and mixing ratio by mixing powder and liquid at the tip of a blowing lance to form a slurry. This invention relates to a method for blowing powder into a blast furnace.

[Conventional technique + Fj] Generally, in order to adjust the internal operation of a blast furnace, pulverized coal as an auxiliary fuel and iron ore powder as a desiliconizing agent for hot metal are injected into the furnace through the tuyeres, The temperature and humidity of the hot air inside the blow pipe are adjusted, the amount of coke introduced from the top of the furnace is adjusted, and the distribution of materials inserted into the furnace is adjusted.

Powdered materials such as pulverized coal and iron ore powder are uniformly mixed with water, oil, etc. in a slurry using a mixer, and then transported via piping and blown into the furnace through the blast furnace tuyeres. ing. At this time, the concentration and flow rate of the slurry or the particle size of the powder or granules are adjusted in order to quickly contribute to the reaction in the furnace or to inject in accordance with the conditions in the furnace.

[Problem that the invention seeks to solve]

However, in such conventional methods of blowing powder and granules, since the powder and granules are mixed with water, oil, etc. in advance to form a slurry, (11) (2) Since it is already in a slurry form, it can be used in situations where the powder or granules and liquid separate due to the difference in specific gravity, making it impossible to blow uniformly or causing blockages in the transportation piping. (3) Slurry There was a problem in that the concentration could not be changed in a timely manner, making it impossible to respond quickly to changes in furnace conditions.

This invention was made in view of these problems, and involves discharging powder and liquid separately using a multi-tube blowing lance, and then mixing them together to form a slurry into a furnace. The aim is to solve the above problems by using a blowing method.

[Means for solving problems]

This invention relates to a method for blowing powder and liquid into a blast furnace from a blast furnace tuyere through a blowing lance. The present invention provides a method for blowing powder and granules by discharging them through separate tubes, mixing the powder and liquid at the tip of the blowing lance, and blowing the mixture into a slurry into a furnace.

[Effect]

Powder is transferred from one tube of the multi-tube blowing lance.
Since the liquid is discharged separately from the other tube, the slurry concentration can be adjusted instantly by changing the discharge amount of the powder and granules and the liquid separately at the appropriate time, and the air Since the slurry concentration can be adjusted by adjusting the flow rate of the transported granular material, it is possible to quickly respond to furnace conditions and contribute to the reaction in the furnace.

〔Example〕

The present invention will be explained below based on the drawings. 1 to 3 show one embodiment of this invention.

In the figure, 1 is a blast furnace, 2 is a furnace body made of refractory bricks, 3 is a tuyere, 4 is a blow pipe for supplying hot air into the furnace, 4a is an iron shell of the blow pipe 4, and 4b is a blow pipe 4 5 is a lance for blowing, 6 is a guide pipe for the lance for blowing, 7 is a supply pipe for powdery material of carbonaceous material or desiliconized material, 8 is a shutoff valve provided in this supply pipe, 9 is a liquid supply pipe for a reaction regulating liquid such as water or oil, and lO is a cutoff valve provided in this liquid supply pipe.

As shown in enlarged detail in FIG. 2, the blowing lance 5 is a double tube consisting of an inner tube 5a and an outer tube 5b disposed coaxially outside the inner tube 5a. The inner pipe 5a is connected to the powder supply pipe 7 via the shutoff valve 8, and discharges the powder and granule 11.
The outer pipe 5b discharges water or oil 12 through a shutoff valve 10. By making the tip of the inner tube 5a shorter than the tip of the outer tube 5b, the ejected granular material 11 and liquid 12 are efficiently mixed to form a uniform slurry 13. The slurry 13 is transferred to the tuyere 3 along with the hot air from the blow pipe 4.
is blown into the furnace. In addition, the slurry 13 consists of water + pulverized coal, water + iron ore powder dual fuel oil + starch coal dual fuel oil + iron ore powder, but in the case of water + pulverized coal, the combustion position of the pulverized coal in the furnace is adjusted by the mixing ratio of water. In the case of floating iron ore powder, the reaction in the blow pipe 4 and tuyere 3 is suppressed by the cooling effect of water, and proper hot metal desiliconization is achieved in the raceway. It can contribute to the reaction.

In addition, during increased production operations, if heavy oil + pulverized coal is used, appropriate furnace heat and gas distribution in the furnace can be obtained, and if heavy oil + iron ore powder is used, the cooling effect of heavy oil will reduce the iron ore inside the blow pipe 4 and tuyere 3. It suppresses the reaction of stone powder and contributes to the desiliconization reaction of hot metal in the raceway, and the heavy oil makes it possible to obtain appropriate furnace heat and gas distribution in the furnace.

When the applicants carried out the above method according to the present invention, they obtained the following results. Pulverized coal having a particle size of about 10 to 500μ is discharged from the inner tube 5a in an amount of 50 to 1000 kg/H, water is discharged from the outer tube 5b in an amount of 10 to 100 kg/H, and both are connected to the blowing lance 5. The results of mixing the slurry at the tip of the tube and blowing it into the furnace are compared with the conventional example, as shown in Figure 3 (81).
50 to 2000 kg of iron ore powder with particle size composition of μ
H amount is discharged, and 10 to 30 kg of heavy oil is discharged from the outer pipe 5b.
FIG. 3(b) shows the result when a slurry was produced by discharging H amount and mixing both at the tip of the blowing lance 5 into the furnace. In addition, the furnace volume is 300
0 rn', blowing temperature 1100°C2 tapping amount 5400t
When water and pulverized coal were injected under the above conditions in a blast furnace of /D, the mixing ratio of water and pulverized coal (kg/t
-p), the pig iron output increased and the fuel ratio (pulverized coal and coke, kg/1-p) decreased.

On the other hand, when iron ore powder is injected as a desiliconization material together with heavy oil under the above conditions, 1. As seen in Figure 3 (bl), as the amount of heavy oil + iron ore powder injected increased, the Si value in the hot metal could be reduced.

As a result of the above, powder (pulverized coal or iron ore powder) and liquid (
When blowing water (water or heavy oil) into the furnace at different flow rates and mixing ratios, it acts as a cooling agent when injected with water, and as an auxiliary combustion agent when injected with heavy oil, resulting in combustion within the tuyere and raceway. By being able to adjust the temperature and temperature, it is possible to adjust the reaction of the powder and granules, contributing to the promotion and stabilization of the reaction in the furnace.In addition, it is possible to adjust the slurry flow rate and mixing ratio for each tuyere. This makes it possible to adjust the balance in the direction of the inner circumference of the furnace, and to quickly adjust the blowing according to the furnace conditions.

In addition, the cooling effect caused by water and heavy oil passing through the inside of the blowing lance 5 prevents thermal deformation or melting of the blowing lance 5 due to hot air reaching up to 1100 degrees Celsius in the blow pipe 4 or radiant heat from inside the furnace. can do.

In this example, powder and granules were discharged from the inner tube 5a and liquid was discharged from the outer tube 5b, but the liquid was discharged from the inner tube 5a.
The powder may be discharged from the outer tube 5b.

〔Effect of the invention〕

As explained above, according to the present invention, in a method for blowing powder into a blast furnace, the powder and the liquid are individually transported through separate tubes of a blowing lance constituted by multiple tubes. The powder and liquid are mixed at the tip of the injection lance to form a slurry, which is then blown into the furnace, making it possible to quickly change the slurry flow rate and mixing ratio. Furnace heat and gas distribution in the furnace can be adjusted quickly and easily in response to furnace conditions. Furthermore, when the liquid is passed through the outer tube of the blowing lance, it is possible to prevent thermal deformation or melting of the blowing lance.

[Brief Description of the Drawings] Fig. 1 is a sectional view of an embodiment according to the present invention, Fig. 2 is a partially enlarged sectional view of Fig. 1, and Fig. 3 shows the results of operation according to the present embodiment compared to the conventional example. In the diagram shown in the comparison of
Figure (a) shows the case where a slurry of water and pulverized coal is injected, and figure (bl) shows the case of injecting the slurry of heavy oil and iron ore powder. 3...tuyere, 5...
...Blowing lance, 5a...Inner pipe, 5b...
...Outer tube, 13...Slurry Fig. 2

Claims (1)

[Claims] In a powder blowing method in which powder and liquid are blown into the furnace from a blast furnace tuyere through a blowing lance, the powder and liquid are individually blown into the furnace by multiple pipes. A blast furnace powder and granular material is discharged through separate pipes of a blast furnace, and the powder and granular material are mixed with a liquid at the tip of the blowing lance and blown into the furnace as a slurry. Blowing method.