KR100213341B1 - Pre-reduction furnace with cross current multi-chamber - Google Patents

Abstract

The present invention relates to a horizontal multi-chamber fluidized bed preliminary reactor of a molten iron reducing facility consisting of a preliminary reduction reactor and a melt reduction reactor.

Iron ore is supplied from the charging hopper 9 having the charging machine 10 to reduce the iron ore by contact with the reducing gas supplied to the upper part through the distribution plate 5 installed at the lower inner side, and the reduced iron is melted. In a fluidized bed pre-reduction furnace having a high temperature cyclone (6) which is sent to a reduction furnace and recovers dust in flue gas, a plurality of reduction chambers (11) (12) (13) are connected in a horizontal manner, and a reduction chamber at one edge thereof. (13) formed an ore charging inlet (3) to receive iron ore from the charging hopper (9), and to reduce the reduced iron in the reducing chamber (11) of the other edge to the melt reduction reactor (1) Characterized in that to form a reduced iron outlet (4),

The simple structure of the equipment and the overall height of the equipment are reduced, and the quality of the reduced spectrometer discharged is uniform and the surface area of the reactor is reduced, thereby reducing the overall heat loss.

Description

Horizontal multi-bed fluidized bed preliminary reactor

The present invention relates to a preliminary reduction furnace of a molten reduction steelmaking facility consisting of a preliminary reduction furnace and a melt reduction reactor, and more particularly, by reducing the ore by connecting a plurality of reduction chambers in a horizontal manner, the facility configuration is simplified and the overall structure of the facility is reduced. The present invention relates to a transverse multi-bed fluidized bed pre-reduction reactor that reduces the height and reduces the quality of the reduced spectroscopy discharged and reduces the surface area of the reactor.

Usually, as a method of producing iron by reducing iron ore, a method of using a blast furnace and a method of melting iron ore reduced by using a shaft furnace in the electric furnace have been conventionally adopted.

In the method for manufacturing molten iron by the blast furnace process, a large amount of coke is used as a heat source and a reducing agent, and iron ore is charged into the blast furnace in the form of sintered ore in order to improve breathability and reducibility. Therefore, the present blast furnace method requires a coke oven facility and a sintered ore manufacturing facility for carbonizing strong coal briquettes.

In other words, the blast furnace method is a process that consumes excessive energy with huge equipment cost, and coke coking raw material coking coal has a small amount of coexistence in the world and is ubiquitous locally.

On the other hand, the reduction method of iron ore by shaft furnace requires a pretreatment step of pelletizing iron ore, and also has a defect that commercialization operation is possible only in an area where natural gas can be easily supplied due to the use of natural gas as a reducing agent and a heat source. The molten reduction method for producing molten iron from powdery iron ore using coking without using coke has been attracting attention as a new steelmaking method.

In such a melt reduction method, a method of charging iron ore reduced in a reducing furnace into a molten furnace and reducing the molten iron is generally employed.

In the reduction furnace, the iron ore is reduced to a solid state before melting the iron ore, and the charged iron ore should be reduced by contact with a high temperature reducing gas generated in the melting furnace. This reduction process is classified into a moving bed or a fluidized bed according to the contact state of iron ore and reducing gas. The granular iron ore having a large particle size distribution is charged into the reduction furnace, and the reducing gas is sent through the dispersion plate at the bottom to flow the iron ore. Reducing fluidized bed formula is evaluated as the most appropriate process as a method for reducing iron ore.

Meanwhile, in the conventional preliminary reduction reactor or direct reduction steelmaking method, as in US Patent No. 5,185,032 or Korean Patent Application No. 95-65208, one or more independent reactors are continuously arranged to contact the countercurrent gas to reduce iron ore by gravity. In order to be able to move, the upstream reactor must be placed at a higher position than the downstream reactor in the placement of each reactor. For this reason, the height of the entire equipment is high. Especially, when the high reduction rate is required in the preliminary reduction process, the preliminary reduction reactor is composed of three or more reactors, so when considering the molten reduction reactor, columnar device, and compaction device located at the lower part, The facilities are getting higher and more complex. In addition, it is difficult to manage the bed level of each reactor in the case of vertical multi-stage arrangement, and the rise of the abnormal bed height in one reactor leads to the abnormal discharge in the downstream reactor, so that the reduced ore that is less than the target residence time is melted and reduced as it is. It is pointed out as a factor that makes the management of yellowing difficult, such as lowering of heat in the melt reduction reactor.

The present invention is to solve the problems of the conventional methods as described above, by installing a single fluidized bed pre-reduction reactor consisting of two or more reduction chambers in a horizontal type in one reactor, the installation configuration is simplified and the overall height of the installation The purpose of the present invention is to provide a transverse multi-bed fluidized bed preliminary reactor which reduces the overall heat loss by reducing the quality of reduced spectroscopy and reducing the surface of the reactor.

1 is a schematic view showing a molten metal reducing plant equipped with a horizontal multi-chamber fluidized bed pre-reduction reactor according to the present invention

Figure 2 is a schematic diagram showing a fluid bed cold model for testing the effect of the present invention.

* Explanation of symbols for main parts of the drawings

1: melt reduction furnace

2: Horizontal multi-stage preliminary reduction reactor

3: ore entrance

4: reduced iron outlet

5: dispersion plate

6: high temperature cyclone

8 gas booster

9: charge hopper

10: charging machine

11,12,13: reduction chamber

14,14a: dividing wall

15,15a: outlet

As a technical configuration for achieving the above object, iron ore is received from a charging hopper equipped with a charging machine to reduce the iron ore by contact with a reducing gas supplied to the upper through a distribution plate installed in the lower inner, the reduced In a fluidized bed pre-reduction furnace with a high temperature cyclone that sends iron to the melting reduction furnace and recovers dust in the flue gas, a plurality of reduction chambers are connected in a horizontal manner, and iron ore can be supplied from the charging hopper to the reduction chamber at one edge. By forming an ore loading inlet, and reducing iron outlet to allow the reduced iron to be discharged to the molten reduction furnace in the reduction chamber of the other side by providing a horizontal multi-chamber fluidized bed pre-reduction path.

Hereinafter, the present invention will be described in more detail.

Figure 1 is a schematic view showing a horizontal multi-chamber fluidized bed pre-reduction reactor according to the present invention, the molten iron production apparatus according to the molten reduction iron method of the melt reduction reactor (1) and the horizontal multi-chamber fluidized bed pre-reduction according to the present invention It consists of the furnace (2).

The horizontal multi-chamber fluidized bed preliminary reduction reactor (2) is located above the molten reduction reactor (1) of the molten iron making apparatus according to the molten reduction steel production method, consisting of two or two reduction chambers, one located at both ends In the reducing chamber of the ore hopper (9) to form the ore entrance (3) to receive the ore and the reduced iron discharge port (4) is formed to discharge the reduced iron.

And the lower part of each reduction chamber is equipped with the dispersion plate 5 for achieving uniform dispersion | distribution of gas.

In addition, the horizontal multi-chamber fluidized bed preliminary reactor (2) of the present invention reduces the high temperature cyclone (6) for recovering the dust of the exhaust gas and the pressure regulating valve (7) for regulating the pressure in the preliminary reactor (2) and some of the exhaust gas. And a gas booster 8 for recycling to gas.

Figure 1 shows an example of a horizontal tri-chamber pre-reduction furnace composed of three reduction chambers for convenience of explanation. It consists of a first reduction chamber 11, a second reduction chamber 12, and a third reduction chamber 13, and the first reduction chamber 11 and the second reduction chamber 12 are connected to the separation wall 14a. The second, third and third reduction chambers 12 and 13 are connected to each other by the separating walls 14, thereby allowing the first, second and third reduction chambers 11, 12, 13 to be connected to each other. The separation walls 14 and 14a are horizontally connected. The ore enters the ore entrance 3 formed in the third reduction chamber 13 through the charging device 10 attached to the lower portion of the charging hopper 9, and thus the ore dropped into the third reduction chamber 13 The heat transfer and reduction reaction takes place in flow contact with the gas supplied to the bottom and rising to the top.

When the fluidized bed rises above the outlet port 15 formed on the upper side of the separation wall 14 by this reaction, it moves to the second reduction chamber 12 through the outlet port 15, and the second reduction chamber The ore entering (12) is also supplied with the lower portion and comes to the upper side, and the reduction reaction occurs continuously in contact with the lower gas.

Similarly, when the fluidized bed rises above the outlet port 15a formed on the upper side of the partition wall 14a by the reaction, the reduced ore moves to the first reduction chamber 11 through the outlet port 15a to further oxidize. The reduction reaction takes place in flow contact with the low gas. The ore that reaches the target reduction rate is discharged through the reduced iron discharge port 4 in the first reduction chamber 11 is charged in the molten reduction reactor (1).

On the other hand, the high temperature reducing gas generated in the melt reduction reactor 1 enters the first reduction chamber 11 requiring the gas having a low oxidation degree, and part of the gas enters the adjacent second reduction chamber 12. This gas is mixed with a part of the gas which is boosted again by the gas booster 8 to return some of the exhaust gas to the second reduction path 12 and the other enters the third reduction path 13.

The ferrous ore charged in this way is subjected to heat transfer and reduction while passing through the third reduction furnace 13, the second reduction furnace 12, and the first reduction furnace 11, and finally reach the target reduction rate. It is discharged from (2).

On the other hand, the exhaust gas exiting each reduction chamber is combined into one and exits through the high temperature cyclone (6). At this time, some of the gas is boosted through the gas booster 8 and returned to the second reduction chamber 12 and the third reduction chamber 13. The dust collected in the high temperature cyclone 6 may be returned to the preliminary reduction reactor or may be entered into the burner of the melting reduction reactor, such as US Pat. No. 4,978,387 or Japanese Patent Laid-Open No. 62-224620.

Hereinafter, an Example demonstrates this invention in detail.

EXAMPLE

In order to demonstrate the effect of the present invention, the present inventors have shown a cold model experimental apparatus composed of three reduction chambers 11 ', 12', 13 ', each having a cross-sectional area of 100 cm 3, as shown in FIG. The experiment was carried out using.

The cold model experiment apparatus is equipped with a charging hopper 9 'and a charging machine 10' for charging ore into the third reduction chamber 13 ', and reducing chambers 11', 12 'and 13'. Is equipped with a cyclone 6 'for treating the exhaust gas discharged from the exhaust gas, and is provided with a blower 41 for blowing air to the lower side of each of the reduction chambers 11', 12 ', 13'. A weighing device 42 for weighing reduced iron is provided.

The ore used in this experiment was a sample which was crushed after firing pure hemateate at 1000 ° C for 2 hours, and the particle size was in the range of 0.08-0.13 mm (average particle size: 1.01 mm), and the flow rate was the first reduction. 4Nm3 / hr in the chamber, 4Nm3 / hr in the second reduction chamber and 4Nm3 / hr in the third reduction chamber. The charging speeds were 1 kg / hr, 1.2 kg / hr and 1.4 kg / hr. Was set to 1 atmosphere.

As a result, it was confirmed that discharge started from about 150 minutes when charged at a charging speed of 1 kg / hr, enabling smooth continuous loading and discharge. In addition, the charging speed of 1.2 kg / hr and 1.4 kg / hr was confirmed to be discharged after 128 minutes and 105 minutes.

As described above, according to the horizontal multi-silicon fluidized bed preliminary reactor according to the present invention, a preliminary reduction reactor for producing molten iron by reducing iron ore using the molten iron reduction method has a configuration in which a plurality of reducing chambers are connected in a horizontal manner. As a result, the system configuration is simple and the overall height of the equipment decreases, and the quality of the reduced spectrometer discharged is uniform, and the surface area of the reactor is reduced, thereby reducing the overall heat loss.

Claims (3)

Iron ore is supplied from the charging hopper 9 having the charging machine 10 to reduce the iron ore by contact with the reducing gas supplied to the upper part through the distribution plate 5 installed at the lower inner side, and the reduced iron is melted. In a fluidized bed pre-reduction furnace having a high temperature cyclone (6) for sending to a reduction furnace and recovering dust in exhaust gas, A plurality of reducing chambers 11, 12, 13 are connected in a horizontal form, forming an ore charging hole 3 to receive iron ore from the charging hopper 9 in the reducing chamber 13 at one edge thereof. The horizontal multi-chamber fluidized bed preliminary reactor, characterized in that for forming a reduced iron outlet (4) for discharging the reduced iron in the reducing chamber (11) of the other side. The discharge chamber (15) (15a) according to claim 1, wherein the reducing chambers adjacent to each other are bounded by barrier walls (14) (14a) and through which reduced ore can pass through the barrier walls (14) (14a). Horizontal multi-chamber fluidized bed pre-reduction furnace, characterized in that each form (). 3. The gas booster (8) according to claim 1 or 2, having a gas booster (8) connected to the downstream side of the cyclone (6), and the gas booster (8) is connected to the lower side of the reduction chamber to boost a part of the exhaust gas to the reduction chamber. Horizontal multi-bed fluidized bed pre-reduction chamber characterized in that the supply.

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