JPH068997Y2 - Pre-reduction furnace for smelting reduction of iron ore - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a pre-reduction furnace for pre-reducing and pre-heating iron ore in smelting reduction of iron ore.

[Conventional technology]

In the smelting reduction of iron ore, the ore is preliminarily reduced (and preheated) using the exhaust gas generated in the smelting reduction furnace. A normal fluidized bed type pre-reduction furnace is suitable for this preliminary reduction, and this type of furnace is often used.

The smelting reduction has the great advantage that iron ore that does not undergo a prior agglomeration treatment can be used, but iron ore has a wide particle size distribution and often contains coarse particles of about several mm. There is a problem that it is difficult to obtain uniform fluidization in the bed. In particular, ores with a large grain size tend to be deposited in the lower part of the fluidized bed, and poor fluidization is likely to occur.

For this reason, as a preliminary reduction furnace, as shown in FIG. 5, the upper surface of the dispersion plate (9) having the gas through holes (10) on the entire surface is formed into a conical (cone) shape, and the through holes are arranged. A furnace is used in which the ore is activated and the fluidization of the ore is promoted appropriately. That is, in this preliminary reduction furnace, ore was charged on the dispersion plate (9), while
After the high-temperature reducing exhaust gas from the smelting reduction furnace is introduced below the dispersion plate (9), it is blown out above the dispersion plate through the gas holes (10), thereby forming a fluidized bed of ore. . In this fluidized bed, gas and ore circulate as shown by arrows in the figure, and active fluidization is achieved. Then, the pre-reduced ore is sequentially discharged from the ore discharge pipe (11) connected to the center of the dispersion plate.

[Problems to be solved by the device]

However, in the pre-reduction furnace having such a structure, as shown in FIG. 5, there is a problem that a stagnant region of ore particles is likely to occur near the upper part of the discharge port, resulting in reduction of the raw material and non-uniformity of preheating. Also, in the stagnant area, the iron ore sintering phenomenon easily occurs,
It may cause clogging of the outlet. In particular, as the size of the furnace body increases, the discharge port diameter also increases, and the range of the stagnant region is wide, which poses a serious operational problem.

In view of such a problem, the present invention aims to provide a pre-reduction furnace having a structure capable of appropriately eliminating the stagnant region of the raw material.

[Means for Solving the Problems]

Therefore, in the first invention of the present application, a large number of gas through holes are formed on substantially the entire surface, and the upper surface has a dispersion plate that is inclined downward toward the center, and the ore discharge port is provided at the valley bottom of the upper surface of the dispersion plate. In the provided pre-reduction furnace, the gas passage holes near the bottom of the valley are configured so that the gas ejection direction is deflected toward the center of the dispersion plate rather than the vertical direction.

In the second invention of the present application, a large number of gas passages are formed on substantially the entire surface, and the upper surface has a dispersion plate that is inclined downward toward the center in the width direction, and the ore discharge port is provided at the valley bottom of the upper surface of the dispersion plate. In the pre-reduction furnace, the gas passage holes near the bottom of the valley are configured so that the gas ejection direction is deflected toward the center of the dispersion plate width direction rather than the vertical direction.

[Action]

The exhaust gas is blown upward from the gas passage holes of the dispersion plate to form a fluidized bed, but the exhaust gas from the gas passage holes near the valley bottom of the top surface of the dispersion plate is closer to the center of the dispersion plate or to the center of the width direction than to the vertical. It flows in a deflected direction, so that the exhaust gas also flows near the upper part of the ore discharge port, and stagnation of the raw material in that part is prevented. Further, the particle circulation in the fluidized bed is strengthened as a whole by the action of the gas flow which is deflected toward the center of the furnace, and the stagnant region is eliminated and the whole bed is uniformly and actively fluidized.

〔Example〕

 FIG. 1 shows an embodiment of the present invention.

The furnace body (1) is formed in a cylindrical shape, inside of which a gas passage hole (3) is provided on substantially the entire surface, and a dispersion plate (2) is provided whose upper surface is conically recessed toward the center. . An ore discharge port (6) is provided at the bottom of the upper surface of the dispersion plate, and an ore discharge pipe (7) is connected to the ore discharge port (6).

The gas passage (3a) near the bottom of the valley, that is, the gas passage (3a) around the ore discharge port (6), is such that the gas ejection direction is deflected toward the center of the dispersion plate rather than vertically (angle θ). Is formed. In this embodiment, the deflection angle θ is 20 °
It is about degree. On the other hand, the gas through holes (3b) outside the gas through holes (3a) are formed so that the gas ejection direction is vertical.

A wind box (4) is provided below the dispersion plate (2), and this wind box (4)
A gas inlet pipe (5) is connected to.

2 and 3 show an embodiment of the second invention of the present application.

The furnace body (1) is configured in a horizontally long rectangular shape in plan view, and a dispersion plate (2) whose upper surface is inclined downward toward the center in the width direction is provided inside the furnace body (1).

At the bottom of the dispersion plate (2), a plurality of ore discharge ports (6) are provided at intervals in the longitudinal direction of the furnace body, and an ore discharge pipe (7) is connected to each ore discharge port (6). There is.

Then, among the gas through holes (3) provided on substantially the entire surface of the dispersion plate (2), the gas through holes (3a) near the valley bottom have a gas ejection direction closer to the center of the dispersion plate width direction than the vertical direction. It is formed so as to be deflected, while the gas passage hole (3b) on the outer side is formed so that the gas ejection direction is vertical.

In the present embodiment, the valley bottom of the dispersion plate (2) is formed in a groove shape, the bottom surface (8) on both sides of each outlet (6) is inclined downward toward each outlet, The ore of the above can be properly flowed down to each discharge port (6).

Fig. 4 shows the state of gas injection and fluidized bed formation in the furnace of the present invention. The gas passage near the ore discharge port (6).
Since it is ejected from (3a) while being deflected toward the center of the exhaust gas furnace, active fluidization occurs even in the region directly above the discharge port.
In addition, the action of the gas flow deflected toward the center of the furnace in this way strengthens the particle circulation throughout the bed.

[Effect of device]

According to the present invention described above, since the structure is such that the gas ejection direction from the gas passage hole near the valley bottom of the dispersion plate is deflected toward the furnace center, stagnation of the raw material immediately above the ore liquid discharge port is prevented. In addition, the particle circulation in the entire layer can be strengthened, whereby the raw material as a whole can be uniformly and actively fluidized, and the occurrence of a sintering phenomenon or the like due to the stagnation of the raw material can be appropriately prevented.

[Brief description of drawings]

FIG. 1 is a vertical sectional view schematically showing an embodiment of the first invention of the present application. 2 and 3 schematically show an embodiment of the second invention of the present application. FIG. 2 is a plan view and FIG. 3 is a sectional view taken along the line III-III in FIG. . FIG. 4 is an explanatory view showing gas ejection and fluidized bed formation in the furnace of the present invention. FIG. 5 is an explanatory view showing a conventional furnace structure. In the figure, (1) is a furnace body, (2) is a dispersion plate, (3) (3a) (3b) is a gas passage hole, (4) is a wind box, (5) is a gas introduction pipe, (6) is The ore discharge port, (7) is an ore discharge pipe.

Claims (2)

[Scope of utility model registration request] 1. A dispersion plate in which a large number of gas passage holes are formed on substantially the entire surface and an upper surface is inclined downward toward the center thereof,
A preliminary reduction furnace in which an ore discharge port is provided at the valley bottom of the upper surface of the dispersion plate, wherein the gas passage hole near the valley bottom is configured so that the gas ejection direction is deflected toward the center of the dispersion plate rather than vertically. Pre-reduction furnace for the smelting reduction of iron ore. 2. A large number of gas passages are formed on substantially the entire surface, and an upper surface has a dispersion plate inclined downward toward the center in the width direction, and an ore discharge port is provided at the valley bottom of the upper surface of the dispersion plate. A preliminary reduction furnace for smelting reduction of iron ore, wherein the gas passage near the bottom of the valley is configured so that the gas ejection direction is deflected toward the center of the dispersion plate width direction rather than the vertical direction.