JP3496233B2 - Oxygen mixing equipment for blast furnace oxygen-enriched blast - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blast furnace oxygen-enriched blast oxygen mixing device for enriching blast furnace air with oxygen to increase pig iron production.

[0002]

2. Description of the Related Art It is well known that, in order to increase the amount of tapped iron in a blast furnace, oxygen is mixed into the blast air, which is introduced into a hot blast stove and heated to a predetermined temperature and introduced into the blast furnace. Conventionally, as shown in FIG. 5, a blast furnace blower 11 and a hot blast stove have been used to mix oxygen into the blast furnace air.
The hot air stove is constructed by blowing oxygen, whose pressure has been increased by the oxygen compressor 14, into the air duct 13 between the hot air and the hot air.
It is directed to 12 to raise the temperature, and this is blown into the furnace from each tuyere of the blast furnace 16.

In this case, in order to introduce oxygen into the blower duct 13 on the discharge side of the blast furnace blower 11, the oxygen compressor 14 must be used to make oxygen higher than the discharge pressure of the blower 11, and a large amount of oxygen must be supplied. There is a problem that the compressor 14 is required, which not only increases the cost but also requires labor for its maintenance. In order to solve the above-mentioned problems, JP-A-47-1870
As shown in FIG. 6, in No. 7 publication, an oxygen supply pipe 10 is connected to a suction duct 9 on the suction side of a blast furnace blower 11 to introduce oxygen into the blown air, and the blower 11 guides it to a hot air stove 12 to raise the temperature. Which blows oxygen-enriched air to the blast furnace 15.

The blown air flowing through the blower duct 9 is
As shown in FIG. 7, it is mixed with oxygen blown out from the oxygen supply pipe 10 and sent to the blast furnace blower 11. In this case, the opening at the tip of the oxygen supply pipe 10 only projects into the duct 9 and has a very simple structure. Since the amount of oxygen enriched with respect to the amount of air flowing in the duct 9 is about several percent, the oxygen blown out from the oxygen supply pipe 10 is controlled by the air flow.

Therefore, not only when the flow of air in the blown air supply duct 9 is uneven, but also in the state of uniform flow, there is a possibility that air with an abnormally high oxygen concentration will form in a band shape. If a small amount of fats and oils or other organic substances are present inside the duct 9, they may come into contact with the air having a high oxygen concentration to cause combustion, which may cause a disaster.

Further, in order to uniformly mix oxygen into the blown air, it is necessary to lengthen the mixing distance between the mounting position of the oxygen supply pipe 10 and the blast furnace blower 11, and the entire apparatus including the equipment associated with the oxygen mixing apparatus. Area increases. Further, the diameter of the duct 9 on the blow-in side of the blast furnace blower 11 is very large, and there is a drawback in that the manufacturing cost is wasteful. In order to solve such a difficulty, Japanese Patent Laid-Open No. 51-100910 discloses a device for enriching oxygen in blast air blown into a blast furnace in which oxygen is supplied in the suction side duct of the blower in a direction perpendicular to the duct wall surface. An oxygen supply device is disclosed in which a tube is inserted and the oxygen supply tube is provided with a large number of openings for blowing out oxygen in a direction substantially perpendicular to the flow of air in a duct.

Further, in Japanese Patent Laid-Open No. 53-5008, an oxygen mixing device having a cylindrical oxygen supply pipe inserted inside the duct at a right angle to the flow direction of blast air supplies a part of the main flow in the duct with oxygen. An oxygen mixing device is disclosed which is provided with a deflector plate for flowing into the wake of the pipe.

[0008]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the prior art disclosed in Japanese Patent Publication, since the oxygen supply pipe is inserted in the blast air supply duct on the suction side of the blower at a right angle to the flow of air, this pressure loss becomes large, and the pressure loss of the blower is reduced. There is a problem that the ventilation efficiency is lowered because of the significant increase.

Further, since the blast air flowing inside the duct is affected to generate vortices, resulting in the vibration of the blower, as disclosed in Japanese Patent Laid-Open No. 535008 in order to prevent this. Since it was necessary to provide a flow straightening plate in the downstream of the oxygen supply pipe, there were problems that pressure loss was increased and the structure was complicated. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and to provide an oxygen mixing device for blast furnace oxygen-enriched blast that can efficiently mix oxygen supplied to the suction side duct of the blast furnace blower. It is a thing.

[0010]

In order to achieve the above object, the present invention according to claim 1 is directed to at least one location of a duct provided on the suction side of a blast furnace blower, and blows air to the wall surface of the duct. An oxygen mixing apparatus for blast furnace oxygen-enriched blast, comprising a large number of nozzle openings for blowing oxygen in a direction substantially perpendicular to the flow of air.

The present invention according to claim 2 further comprises a header surrounding a portion of the duct having a large number of nozzle openings,
The oxygen mixing apparatus for blast furnace oxygen-enriched blast according to claim 1, wherein an oxygen supply pipe is connected to the header.

[0012]

In the present invention, since nothing is attached to the inside of the duct on the suction side of the blast furnace blower, oxygen is blown from the nozzle opening provided on the wall surface, the pressure loss in the duct is not increased at all. The efficiency of the blast furnace blower does not decrease. Furthermore, there is no need to provide a rectifying plate or the like, because vibration and the like do not affect the flow of blown air in the blower duct.

Compared with the case of performing oxygen enrichment on the discharge side of the blast furnace blower, it is not necessary to install a compressor for oxygen boosting, operating costs and maintenance costs are not required, and the control of the amount of oxygen blown in is easy. Become.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The present invention is similar to the case shown in FIG.
It is premised that oxygen is introduced into the blast air flowing through the suction side blower duct 9 of FIG. 1, but as shown in FIGS. A large number of nozzle openings 7 are provided to blow out oxygen in a direction substantially perpendicular to the flow.

A portion of the air duct 9 provided with a large number of nozzle openings 7 is surrounded by a header 8 and an oxygen supply pipe 10 is connected to the header 8. Although the drawing shows the case where a large number of nozzle openings 7 are provided centrally at one location of the blower duct 9, they may be provided at a plurality of locations separately. Although a large number of nozzle openings 7 provided on both side wall surfaces of the blower duct 9 are shown as being circular, the present invention is not limited to this and may be square or polygonal other than circular. Further, the nozzle opening 7 may be provided on the upper surface or the lower surface of the air blowing duct 9 as required.

According to the oxygen mixing apparatus of the blast furnace oxygen-enriched blast according to the present invention, the oxygen introduced from the oxygen supply pipe 10 to the header 8 has a large number of nozzle openings provided on both side wall surfaces of the suction side blast duct 9. Since oxygen is blown from the air blower 7 in a direction substantially perpendicular to the blast air flowing in the blast duct 9, the oxygen is uniformly and rapidly mixed into the blast air without causing a drift.
Further, in the present invention, since it is not necessary to provide the blower duct 9 with a blower resistance, the pressure loss is not increased, and a rectifying plate for preventing uneven flow is also unnecessary. Oxygen blown into the blown air is quickly mixed, so that there is no need to worry about trouble such as fire inside the blower.

Table 1 shows the heat insulating effect of the blower in the case of performing the intake side oxygen enrichment using the oxygen mixing apparatus according to the present invention in comparison with the result of the blow side oxygen enrichment. In all cases, the blown air volume was 6900 Nm ³ / min and the oxygen injection volume was 15000 Nm ³ / hour.

[0018]

[Table 1]

As shown in Table 1, in the No. 1 and No. 2 blowers, even if the oxygen enrichment system was switched from the blower side to the suction side of the blower, no decrease in the adiabatic efficiency of the blower was observed. Then 3
The mixed state of oxygen in the cross-section of the suction side duct 9 was confirmed when oxygen was blown into the blown air from a large number of nozzle openings 7 provided in the suction side duct 9 according to the present invention using a No. blower. FIG. 3A shows the confirmation position of the oxygen mixed state on the suction side of the blower. The amount of blast air is 647
0Nm ³ / min, the amount of oxygen blown in is 333.3Nm ³ / min, and the concentration after the oxygen supplied is completely mixed with blast air is 24.8%.

FIG. 4 shows a mixed state of oxygen in the suction side duct of the No. 3 blower. As shown in FIG. 4, it can be seen that the oxygen is mixed evenly by the blower with almost no variation.

[0021]

According to the present invention, since oxygen is mixed from the nozzle opening provided on the duct wall surface without providing the oxygen outlet inside the suction side duct, the pressure loss is not increased and the blower efficiency is improved. Oxygen enrichment on the suction side is possible without lowering. Further, since it does not affect the flow of blown air in the duct and does not generate vibration or the like, it is not necessary to install a current plate or the like. The blown oxygen mixes with the blown air as soon as possible, so there is no need to worry about fires inside the blower.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an apparatus of the present invention.

FIG. 2 is a schematic cross-sectional view taken along the line AA of FIG.

FIG. 3 is a schematic perspective view showing the arrangement of the device of the present invention.

FIG. 4 is a distribution diagram showing a mixed state of oxygen according to the present invention.

FIG. 5 is an explanatory view showing a conventional oxygen enrichment device.

FIG. 6 is an explanatory view showing a conventional oxygen enrichment device.

FIG. 7 is an explanatory diagram showing a conventional oxygen enrichment device.

[Explanation of symbols]

7 nozzle opening 8 header 9 Blower air supply duct 10 Oxygen supply pipe 11 Blast furnace blower 12 hot stove 13 air duct 14 Oxygen booster compressor 15 Oxygen introduction tube 16 blast furnace

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yozo Sasaki 1-chome, Mizushima Kawasaki-dori, Kurashiki City, Okayama Prefecture (no address), Kawasaki Steel Co., Ltd. Mizushima Works (58) Fields investigated (Int.Cl. ⁷ , DB name) ) C21B 9/00-9/16 B01F 3/02

Claims (2)

(57) [Claims] 1. A number of nozzle openings are provided at at least one position of a duct provided on the suction side of a blast furnace blower, and a wall surface of the duct is provided with a plurality of nozzle openings for blowing oxygen in a direction substantially perpendicular to the flow of blown air. An oxygen mixing device for blast furnace oxygen-enriched blast characterized by the above. 2. An oxygen mixing apparatus for blast furnace oxygen-enriched blast according to claim 1, further comprising a header surrounding a portion of the duct having a large number of nozzle openings, and an oxygen supply pipe connected to the header. .