KR20010057420A - Apparatus for supplying the back-up gas in fluidized bed reactor - Google Patents

Abstract

PURPOSE: A supplying apparatus for back-up gas of a flow type reduction furnace capable of solving defluidization simply and stably by detecting pressure difference and temperature change generated when a nozzle is clogged and back-up supplying nitrogen gas to the lower part of a reactor is provided, which can normalize operations quickly and makes it possible to stably perform long-term operations. CONSTITUTION: This supplying apparatus comprises: exhaust pipe differential pressure gauges(25)(35)(45) for detecting pressure difference and temperature gauges(26)(36)(46) for detecting reducing gas temperature placed at ore discharge pipes(23)(33)(43); furnace differential pressure gauges(27)(37)(47) for detecting pressure difference of the upper and lower part of distribution plates(24)(34)(44); and nitrogen gas lines(29)(39)(49) having on-off valves(28)(38)(48) to supply nitrogen gas to a preheating furnace(40), a preparatory reduction furnace(30) and a final reduction furnace.

Description

Back-up gas supply device for fluidized-reduction reactor {APPARATUS FOR SUPPLYING THE BACK-UP GAS IN FLUIDIZED BED REACTOR}

The present invention is to solve the abnormal operation of the fluidized bed reduction furnace in the molten reduction process of the multi-stage flow reduction furnace for manufacturing molten iron using a wide range of particle size ore to quickly switch to a stable normal operation to perform a long time operation In more detail, in the multi-stage flow reduction reactor, iron ore is charged to the side wall of each reactor in turn in the process of final charging of the ore into the melt gasification furnace while passing through the preheating furnace, the preliminary reduction reactor and the final reduction furnace. On the other hand, the reducing gas is generated in the molten gasifier and supplied to the lower part of each reactor through the gas discharge pipe connected to the final reduction, preliminary and preheating furnaces, and is reduced while interacting with the ore charged through the dispersion plate. After the reaction proceeds continuously, molten gas is produced by producing reduced iron, the final reduction product. In the process of charging the furnace, if the fluidized bed formation and the ore flow cannot be achieved in the normal reactor due to the increase of the differential plate pressure of each reactor, the solution is quickly solved and converted into the normal operation to enable long-term operation. The present invention relates to a back-up gas supply apparatus for a flow reduction reactor.

In general, a method of using a blast furnace has been mainly used as a method of producing molten iron by reducing iron ore. However, this blast furnace method is used to pre-process the raw material for the efficiency of the manufacturing process.

In other words, iron ore is charged into the blast furnace in the form of sintered ore produced through a sintering process to improve breathability and reducibility, and coke used as a heat source and a reducing agent is essential to coking strong coking coal.

Accordingly, the pretreatment of such raw materials not only has to have additional facilities requiring huge investment costs, but also faces many problems with environmental regulations that are being strengthened around the world. In addition, the effective utilization of fine iron ore, which accounts for more than 70% of the world's iron ore reserves, is required, and coking coking raw material coking coal is not only low in amount but also geopolitically distributed, so the supply and demand problems are increasing due to the increase in steel demand. have.

In order to overcome the problems of the blast furnace method and to use the molten iron ore and without the pre-treatment of ordinary coal directly melt melting method has emerged in recent years, a typical example is US Patent No. 4,978,378.

In the method described in US Patent No. 4,978,378, the use of raw iron ore and coal can be used to simplify the process and equipment by omitting the pretreatment of raw materials such as the sintering process and the coking process, compared to the existing blast furnace method.

As shown in FIG. 1, the indirect iron ore is indirectly formed using a melting gasifier 10 and a reducing gas generated in the molten gasifier 10 that are responsible for producing a reducing gas and melting a reduced ore by gasification of charged coal as shown in FIG. 1. It can be divided into a multi-stage flow reduction reactor (100) consisting of a preheating furnace 40, a preliminary reduction reactor (30) and a final reduction reactor (20) and its auxiliary facilities to reduce.

That is, in this multi-stage flow reduction path 100, the ore in the charging bin 60 is preheated through the ore loading pipe 63, the first and second ore and the third ore discharge pipes 23, 33, 43. In addition, the flow is reduced through the preliminary reduction path 30 and the final reduction path 20 and charged into the melt gasifier 10, the reducing gas generated in the melt gasifier 10 is the rising pipe (11), The first and second gas discharge pipes 22 and 32 are introduced into the final reduction path 20, the preliminary reduction path 30, and the preheating path 40, respectively, so that the first reactors 20, 30, and 40 are first. Gas is supplied to the fluidized bed through the 2 and 3 dispersion plates 24, 34 and 44 to produce molten iron, and the finished gas is gas discharge pipe 42, wet damper 50, exhaust gas pipe 51 and It is discharged to the outside through a flare stack.

The reduction process using the flow reduction reactor 100 can be divided into a moving bed and a fluidized bed type according to the contact state of the iron ore and reducing gas, the iron ore having a wide particle size distribution is charged into the flow reduction reactor and the reducing gas is each reactor (20). A fluidized bed equation, which is sent through the dispersion plates 44, 34 and 24 underneath (30) and (40) to reduce the flow of iron ore, is known as a suitable method for reducing such iron ore.

In order to effectively reduce the iron ore having such a large particle size distribution and then charge it into the melting gasifier 10, a plurality of conical flow reduction furnaces, including a preheating furnace 40, a preliminary reduction reactor 30, and a final reduction reactor 20, may be used. Mainly used.

However, the reducing gas generated in the melt gasifier 10 contains a large amount of dust to pass through the dispersion plates 44, 34, 24 of each reactor 40, 30, 20. In addition, dust is accumulated in the nozzles formed in the dispersion plates 44, 34, and 24 in the process of being supplied into each of the reactors 40, 30, and 20. In the extreme case, normal gas flow was not possible due to the clogging of the nozzles of the dispersion plates 44, 34 and 24. In extreme cases, the operation had to be stopped.

In order to solve such a problem, Japanese Unexamined Patent Publication No. 9-157719 installed a dropping tank to handle falling falls caused by unstable operation.

However, in the multi-stage flow reduction reactor, ore loading and discharge due to unstable operation and ore flow problems in each reactor could not only reduce the stability and efficiency of the operation but also cause the operation to stop.

Accordingly, the present invention has been made to solve the above problems, the object of the present invention is to detect the differential pressure and temperature change generated when the nozzle clogged so that the normal fluidized bed formation and ore flow is made, back-up supply of nitrogen gas to the bottom of the reactor By providing a simple and stable solution to the non-fluidization phenomena, it is intended to provide a back-up gas supply device for a flow reduction path that can perform normal operation and stable long-term operation.

1 is a schematic diagram showing a general flow reduction path,

Figure 2 is a block diagram showing a flow reduction path employing a backup gas supply apparatus according to the present invention.

* Explanation of symbols for the main parts of the drawings *

10 .... Melt Gasification Furnace 20 ..... Final Reduction Furnace

30 .... preliminary reduction furnace 40 ..... preheating furnace

50 .... Wet vibration damper 60 ..... ore loading bin

11 .... reducing gas riser 51 ..... flue gas

21, 31, 41 .... 1st, 2nd and 3rd control valves 22, 32 ..... 1st, 2nd gas exhaust pipe

23, 33, 43 .... 1,2, and 3 ore discharge pipes 24, 34, 44 .... 1,2, and 3 dispersion plates

25, 35, 45 .... 1,2,3 discharge pipe differential pressure gauge 26,36,46 .... 1,2,3,3 Thermometer

27,37,47 .... 1st, 2nd and 3rd differential pressure gauges 29,39,49 .... 1st, 2nd and 3rd nitrogen gas lines

The present invention as a technical configuration for achieving the above object,

The ore in the charging bin is flow-reduced through the preheating, preliminary and final reduction paths through the ore charge pipes, the first and second ore discharge pipes, charged into the melt gasifier, and the reducing gas produced in the melt gasifier. Is fed into the bottom of the final reduction, preliminary and preheating furnaces through the riser, the first and second gas discharge pipes and supplied to the fluidized bed through the first, second and third dispersion plates of each reactor to produce molten iron. The finished gas is discharged through the wet vibration suppressor in the

The first, second and third ore discharge pipes having the first, second and third control valves for controlling the supply flow of the ore include first and second discharge pipe pressure gauges for detecting a pressure difference between an inlet end and an outlet end; The first, second, and third thermometers for detecting the reversed gas temperature at the time of backflow are mounted, respectively, and the first, second, and third furnace pressure gauges for detecting the upper and lower pressure differentials of the first, second, and third dispersion plates, respectively. And the first and second gas discharge pipes of the first, second and third thermometers, the first and the second and third discharge pipe pressure gauges, and the first and second and third furnace pressure gauges that detect abnormal temperature rises and pressure differences. The first, second and third nitrogen gas lines having first, second and third opening and closing valves for connecting nitrogen gas to the preheating, preliminary and final reduction paths by the detection signal. By providing a back-up gas supply device for the flow reduction path.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

2 is a block diagram showing a backup gas supply apparatus for a flow reduction path according to the present invention, the backup gas supply device 1 of the present invention is the first, second and third dispersion plates 24, 34, 44 Preheating furnace constituting the nitrogen gas flow reducing reactor 100 to suppress the clogging of the nozzle, the reverse flow of the reducing gas through the first, second and third ore discharge pipes (23, 33, 43) and non-fluidization ( 40), backup supply to the lower side of the preliminary reduction path 30 and the final reduction path 20 to prevent defluidization. That is, the first supply of the ore supplied from the ore charging bin 60 into which the ore is loaded is continuously supplied to the preheating furnace 40, the preliminary reduction reactor 30, the final reduction reactor 20, and the melt gasifier 10. , 2 and 3 ore discharge pipes 23, 33, 43 in the preheating furnace 40 to the preliminary reduction path 30 side, from the preliminary reduction path 30 to the final reduction path 20 side, the final reduction First, second and third control valves 21, 31 and 41 are mounted to properly control the ore flow from the furnace 20 to the molten gasifier 10 side.

In addition, the first, second and third ore discharge pipes 23, 33 and 43 have first, second and third discharge pipe pressure gauges 25 (to detect the pressure difference between the inlet and outlet ends of the respective inner tubes. 35 and 45, nozzles formed in the first, second and third dispersion plates 24, 34 and 34 at the front end of the first, second and third regulating valves 21, 31 and 41. When clogged reducing gas flows back through the first, second, and third ore discharge pipes 23, 33, 43, the first, second, and third thermometers 26 may detect a sudden change in temperature of the reducing gas that flows back therethrough. 36 and 46 are respectively mounted.

In addition, when the non-fluidization occurs in the preheating furnace 40, the preliminary reduction path 30 and the final reduction path 20 due to the nozzle clogging, the first, second and third dispersion plates 24, 34 ( The first, second, and third low-pressure manometers 27, 37, 47 are provided so as to be able to detect the pressure difference in the upper and lower parts of 44.

Meanwhile, the first, second and third thermometers 26 and 36 (the first and the third gas discharge pipes 22 and 32 to which the reducing gas of the molten gasifier 10 is supplied) are provided. 46 and the first, second, and third discharge pipe pressure gauges 25, 35, 45 detect abnormal temperature rises in the first, second, and third ore discharge pipes 23, 33, 43; The pressure difference is detected, and the pressure difference greater than or equal to the set value is detected in the first, second, and third dispersion plates 24, 34, 44 by the first, second, and third road pressure gauges 27, 37, 47. First, second, and third nitrogen gas lines 29, 39, 49 having first, second, and third open / close valves 28, 38, and 48 that are opened by a detection signal generated at the time. do.

Accordingly, the nitrogen gas in the opening operation of the open / close valves 28, 38, and 48 is backed up to the lower side of the preheating furnace 40, the preliminary reduction passage 30, and the final reduction passage 20. Through the nozzle holes of the first, second, and third dispersion plates 24, 34, and 44 blocked while being supplied, the fluidization in the furnace is solved to enable normal operation.

The operation and effects of the present invention having the above-described configuration will be described below.

First, the molten iron manufacturing process in the flow reduction path 100 is the ore preheating furnace 40, the preliminary reduction path 30 and the ore through the ore charging pipe 63 from the charging bin 60 as shown in FIG. The flow is reduced while passing through the final reduction path 20 and charged into the melt gasifier 10, the reducing gas generated in the melt gasifier 10 is the final reduction path 20, preliminary through the rising pipe (11) It is introduced into the lower part of the reduction furnace 30 and the preheating furnace 40 to form a fluidized bed through the first, second, and third dispersion plates 24, 34, 44 installed in each reactor 20, 30, 40. The ore charged while being evenly distributed from the bottom to the top is to be reduced by the reducing gas.

When the ore loading starts to the preheating furnace 40 side, the third opening and closing valve 41 of the third ore discharge pipe 43 is open, so that the flow of reducing gas is transferred to the preheating furnace through the second gas discharge pipe 32. At the same time as being supplied to the lower portion, a large amount of gas flows through the third ore discharge pipe 43.

Accordingly, in the preheating furnace 40, the charged ore does not flow smoothly, and the ore sinks on the third dispersion plate 44 to block the nozzle of the third dispersion plate 44, and thus the third dispersion. The non-fluidization phenomenon in which the differential pressure increases in the plate 44 occurs, so that the effective preheating of the ore is impossible, and further, the increase in the differential pressure of the dispersion plate 44 means an increase in the ore density therein. Due to this, the exit of the ore charge tube 63, which injects the ore from the ore charge bin 60 to the preheating furnace 40 side, is blocked, so that no more ore charges can be made, thereby making it impossible to proceed with the operation. Cause.

Therefore, when initially filling the ore in the preheating furnace 40, the third control valve of the third ore discharge pipe 43 so that the reducing gas flows only to the lower portion of the third dispersion plate 44 of the preheating furnace 40 ( 41) the ore is charged into the preheating furnace 40 in a closed state, so that a smooth fluidized bed is formed, and the height of the fluidized bed in the preheating furnace 40 gradually increases to rise to the inlet end of the third ore discharge pipe 43. When the third control valve 41 is gradually opened to discharge the ore through the third ore discharge pipe 43 to secure the fluidized bed of the preliminary reduction path (30).

And, if the fluidized bed height is formed higher than the outlet end of the third ore discharge pipe 43, the ore smoothly through the third ore discharge pipe 43 in the preheating furnace 40 even when the third control valve 41 is opened. Since the reducing gas does not flow back while being discharged, thereafter, the third control valve 41 is continuously opened to continuously discharge and charge the ore from the preheating furnace 40 to the preliminary reduction reactor 3. do.

By performing the operation as described above, if the height of the fluidized bed of the preliminary reduction path 30 increases to the inlet end height of the second ore discharge pipe 33, the second control valve 31 is gradually opened to the preliminary reduction path 30. A fluidized bed is formed, and the height of the fluidized bed of the preliminary reduction path 20 is increased to be higher than that of the outlet of the second ore discharge pipe 33 so that the second control valve 31 is opened to pass through the second ore discharge pipe 33. When the ore discharge is continuously possible without the backflow of the maid reducing gas, the second control valve 31 is opened to continuously discharge or charge the ore continuously.

By performing the operation as described above, when the fluidized bed height of the final reduction path 20 increases to the inlet end height of the first ore discharge pipe 21 and the fluidized bed is formed to the inlet end of the first ore discharge pipe 23, the first control valve 21 is formed. In the process of discharging the ore to the molten gasifier 10 by periodically opening the), the height of the fluidized bed of the final reduction path 20 is increased to be higher than the exit end of the first ore discharge pipe 23 and the first control valve 21. Even if it is open, if the discharge is possible continuously without the discharge of ore and the backflow of gas to open the first control valve 21 to ensure a smooth ore discharge continuously.

The process of charging or discharging ore into each reactor 20, 30 and 40 at the beginning of the operation and the first, second and third control valves 21 of the ore discharge pipes 23, 33 and 43 (31) (41) in the course of performing normal operation by the large amount of dust contained in the reducing gas or the flow phenomenon of the ore charged in the reactor 20, 30, 40 is unstable due to the falling light generated at this time When the nozzles formed in the first, second, and third dispersion plates 24, 34, 44 of each of the reactors 20, 30, and 40 are gradually closed, the first, second, and third dispersion plates 24 are closed. The first, second, and third pressure gauges 27, 37, and 47 detect the increase in the differential pressure, which is the pressure difference between the upper and lower portions, at the boundary between (34) and (44).

As described above, when the differential pressure value detected by the first, second, and third pressure gauges 27, 37, 47 increases to a predetermined value or more, the first, second, and third dispersion plates 24, 34 ( 44) Normal operation is impossible because the ore flow phenomenon in the upper part is unstable and the discharge and charging of ore through the first, second and third ore discharge pipes 23, 33 and 3 is also very unstable, and in severe cases, reduction The flow of gas is introduced into the lower portion of each reactor 20, 30, 40, and is not supplied to the fluidized bed through the first, second, and third dispersion plates 24, 34, 44, and each ore discharge pipe 23 ( 33) (43) flow of reducing gas occurs so that the reducing gas necessary for the discharge and charging of ore as well as the flow in the upper fluidized bed does not pass through the first, second and third dispersion plates 24, 34, 44. As it is supplied, non-fluidization phenomenon occurs.

Eventually, a fluidized bed is formed only directly above the first, second, and third dispersion plates 24, 34, 44, which are lower portions of each reactor 20, 30, 30, thereby accelerating nozzle clogging of the dispersion plate. In severe cases, the ore flows through the first, second, and third ore discharge pipes 23, 33, and 34 back into the upper ore charge bin 60 and the reactor 20, 30 in the same manner as the reducing gas, and then the lower reactor 20 While the fluidized bed of (30) (40) is extinguished, the fluidized bed volume of the upper reactor (20) (30) (40) is rapidly increasing, but the ore flow is not smooth, and normal operation is impossible, and the serious situation of operation stoppage If you develop until it happens.

Therefore, when a flow of reducing gas is generated in each of the ore discharge pipes 23, 33 and 43 during operation, the first and second control valves 21, 31 and 41 mounted thereon are closed to reduce the gas. And it is possible to prevent the reverse flow of the ore, but in general, if the reducing gas backflow to the first, second and third ore discharge pipes (23) (33) (43) occurs, the reducing gas is a high temperature, accompanied by a sudden increase in temperature, Accordingly, the operation of the first, second, and third control valves 21, 31, 41 may not be performed smoothly, and thus, the reverse flow of the reducing gas may not be blocked, and the operation may be left as it is.

As described above, the nozzles of the first, second and third dispersion plates 24, 34 and 44 are blocked by dust and falling clouds, and the first, second and third dispersion plates 24 and 34 during normal operation. When the pressure difference in the upper and lower portions of the upper and lower parts of 44 is increased to 300 mmbar or more rapidly, this is detected by the first, second and third pressure gauges 27, 37, 47, and the detection. The first, second, and third ore discharge pipes 23, 33, 43, in which the first, second, and third control valves 21, 31, 41 are closed and the ore is loaded by the detected detection signals, As it is closed, ore loading and gas supply through it are not made.

At the same time, the first, second and third nitrogen gas lines 29, 39, 49 are detected by detection signals of the first, second, and third pressure gauges 27, 37, 47 that detect abnormality of the set pressure difference. Since the first, second, and third open / close valves 28, 38, and 48 mounted on the valves are opened, nitrogen gas is discharged through the open first, second, and third nitrogen gas lines 29, 39, and 49. The differential pressure is lowered while purging the first, second and third dispersion plates 24, 34, 44 by back-up supply to each reactor 20, 30, 40 side. At this time, the gas required for the flow is supplied to block the clogging phenomenon of the first, second and third dispersion plates 24, 34, 44, and after the minimum flow state is maintained, the corresponding first, second, and third Close the control valve (21) (31) (41), and stops the nitrogen supply to perform normal operation again while maintaining the normal reducing gas flow.

In addition, the fluidization occurs due to nozzle clogging of the first, second and third dispersion plates 24, 34, 44 during operation, and the first, second, and third ore discharge pipes 23, 33, 34 When the reverse flow phenomenon of the reducing gas through () occurs, the pressure difference between the inlet end and the outlet end in the first, second and third ore discharge pipes 23, 33, 43 is generated by the reducing gas flowing back from the lower side reactor. Done. At this time, the inlet and outlet ends of the first, second, and third ore discharge pipes 23, 33, 43 are installed by the first, second, and third discharge pipe pressure gauges 25, 35, 45. When the pressure difference between the first and second and third discharge pressure gauges 25, 35 and 45 is detected, the pressure difference between the first and the second and third control valves 21 ( 31) (41) should be closed immediately, but if normal operation is not possible, the first, second and third opening and closing valves 28, 38, 38 will be opened to open the preheating furnace 40, the preliminary reduction passage 30 and the final reduction. Nitrogen gas is purged and supplied to the lower side of the furnace 20. Then, the gas required for the flow is supplied to the lower side of the reactor 20, 30, 40, the clogging phenomenon of the first, second and third dispersion plates 24, 34, 44 is eliminated, and the minimum flow state As described above, when the corresponding first, second, and third control valves 21, 31, and 41 are closed, the supply of nitrogen gas is stopped to maintain normal reducing gas flow to perform normal operation again.

In addition, the reverse flow of reducing gas through the first, second, and third ore discharge pipes 23, 33, 43 occurs during operation, and thus, in the first, second, and third ore discharge pipes 23, 33, 43. If it is detected that the gas temperature detected by the first, second, and third thermometers 26, 36, 46 is rapidly increased above a set temperature change value of 50 ° C, the first, second, and third thermometers that detect the gas temperature are detected. The corresponding first, second and third open / close valves 28, 38, 38 are opened by the detection signals of (26), (36), (46), and the preheating passage (40), the preliminary reduction passage (30) and Nitrogen gas is purged and supplied to the lower side of the final reduction path 20.

Then, the gas required for the flow is supplied to the lower side of the reactor 20, 30, 40, the clogging phenomenon of the first, second and third dispersion plates 24, 34, 44 is eliminated, and the minimum flow state After the maintenance, as described above, the corresponding first, second and third control valves 21, 31, and 41 are closed to stop the supply of nitrogen gas to perform normal operation again while maintaining a normal reducing gas flow.

As described above, a reducing gas flow is normally performed into each of the reactors 20, 30, and 40, and the differential pressure values at the upper and lower portions of the dispersion plates 24, 34 and 44, and the first, second and third ores. When the differential pressure value and the temperature change in the discharge pipes 23, 33, 43 are normally returned, and the fluidized bed height is normalized, the first and second ore ore discharge pipes 23, 33, 43 are installed in the Stable operation by opening the 1,2 and 3 control valves 21, 31 and 41 to continuously and smoothly normal ore charging and discharging to each reactor 10, 20, 30 and 40. It can be done with

<Example>

1) Specifications and conditions of the liquid return path

end. Preheating Furnace (40), Preliminary Reduction Furnace (30), Final Reduction Furnace (20)

-Reduction part (distribution plate 24, 34, 44) inner diameter: 0.3m

-Enlarged part inner diameter: 0.7m

-Conical bottom angle: 4 degrees

-Slope height (on the surface of the dispersion plate): 4.0m

-Cylindrical upper height: 2.5m

-Depth of dispersion plate: 3.0m

I. Raw material

a) iron ore (-8mm)

-Chemical composition: T. Fe: 62.17%, FeO: 0.51%, SiO2: 5.5%,

TiO2: 0.11%, Mn: 0.05%, S: 0.012%, P: 0.65%,

Decisions: 2.32%

-Particle size distribution: -0.05mm: 4.6%, 0.05 ~ 0.15mm: 5.4%,

0.15-0.5mm: 16.8%, 0.5-4.75mm: 59.4%,

4.75-8mm: 13.8%

b) gas

-Chemical composition: CO: 65%, H2: 25%, CO2: 5%, N2: 5%

-Temperature in the flow reduction furnace: Final reduction furnace (20): 850 ℃,

Preliminary reduction furnace (30): 800 ℃,

Preheating Furnace 40: 750 ℃

-Flow rate: Steady state: 1.7 m / s (distributed plate)

-Pressure: 2.5 ~ 3.0 bar, g

Experimental condition Average normal operation (hr) Normal restart time (hr) Experiment 1 Conventional 60 120 Experiment 2 The present invention 240 5

As a result of the reduction reaction of the powder ore according to the specifications, conditions and experimental conditions of the fluid reduction reactor 100 as described above, ore loading into each reactor and the fluidized bed height in each reactor were kept constant, the first and the second and The first, second and third dispersion plates 24 generated in the process of continuous charging / discharging by opening each control valve 21, 31, 41 of the three-ore discharge pipes 23, 33, 43. Increasing the differential pressure in (34) and (44) and backflow of reducing gas and ore through the first, second and third ore discharge pipes (23), (33) and (43) occur in the reactor (20) (30) (40). In the first and second and third ore discharge pipes 23, 33 and 43, when the non-fluidization occurs, the first and second and third thermometers 26 and 36 which detect the change in temperature and the differential pressure. 46) The first, second and third discharge pressure gauges 25, 35, 45 and the first, second, and third dispersion plates 24, 34, 44 detect the upper and lower differential pressure values. Of the nitrogen gas lines 29, 39 and 49 corresponding to the detection signals of the 1,2 and 3 road differential pressure gauges 27, 37 and 47. And by opening the waste valve 28, 38, 48, Backup supplying nitrogen gas to the lower side of each of the reactors 20, 30, 40, which will be resumed the normal operation while maintaining forms a continuous fluid bed.

Accordingly, as shown in Table 1 above, when the operation instability occurs, the operation duration is greatly extended, while the operation restart time is drastically reduced, and the overall operation is performed stably for a long time. It can greatly improve facility utilization rate and operation productivity.

In this case, the gas utilization rate is about 30 to 35%, the gas source unit is 1300 to 1500 Nm 3 / ton-ore, the reduction rate of iron ore charged from the preheating furnace 40 to the preliminary reduction reactor 30 is 10 to 15%, The reduction rate of iron ore discharged from the preliminary reduction reactor 30 and charged into the final reduction reactor 20 is 30 to 40%, and the reduction rate of the reduced iron charged into the melt gasification furnace 10 in the final reduction reactor 20 is It is 85 ~ 90%, and it is possible to deal with the temporary operation instability quickly and solve it, so that the flow reduction path can be stable and operate for a long time.

According to the present invention as described above, the iron ore is finally charged into the melt gasifier through the preheating, pre-reduction and final reduction in the ore charging bin of the upper, and reducing gas generated in the molten gasifier to the final reduction furnace Through the pre-reduction furnace and pre-heater distribution plates, continuously reacting with the charged ore and continuously proceed with the reduction reaction, and then produce the reduced iron, the final reduction product, and load it into the melt gasifier. If the differential pressure increases due to the blockage of the plate, and this causes the fluidized bed formation and the ore flow in the reactor to fail, the differential pressure in the upper and lower part of the blocking plate, the temperature in the ore discharge pipe, and the differential pressure change are applied to each reactor. Equipped with the appropriate low differential pressure gauge, discharge pipe differential pressure gauge and thermometer, and the corresponding nitrogen gas line when the differential pressure and temperature change over the set value By opening and backing up nitrogen gas to the lower side of each reactor, it is possible to quickly solve dispersion plate clogging, reverse flow and non-fluidization of reducing gas in each reactor, thereby effectively preventing unstable operation and It is possible to switch quickly to an operation and to enable a long time operation, thereby achieving an effect of remarkably improving work productivity.

Claims (5)

The ore in the charging bin 60 is preheated 40, preliminary reduction path 30 and the final reduction path through the ore charge pipe 63, the first, second and third ore discharge pipes 23, 33, 43 Flow-reduced while passing through the (20) is charged into the melt gasifier 10, the reducing gas generated in the melt gasifier 10 is the rising pipe (11), the first and second gas discharge pipe (22) (32) Through the final reduction path 20, the preliminary reduction path 30 and the preheating furnace 40 through the first through the first and second dispersion plates 24, 34 of each reactor 20, 30, 40 In the fluidized-bed reactor that is supplied to the fluidized bed through (44) to produce molten iron, the gas after the reduction process is discharged through the wet damper (50), Inlet and outlet ends of the first and second or third ore discharge pipes 23, 33 and 43 having first and second and third control valves 21, 31 and 41 to control the supply flow of the ore. First, second and third discharge tube pressure gauges 25, 35 and 45 for detecting the pressure difference between the first and third and third and third and third and third thermometers 26 and 36 for detecting the reducing gas temperature backflowed during gas backflow. The first, second, and third road differential pressure gauges 27, 37 (37), respectively, are mounted to detect upper and lower pressure differentials of the first, second, and third dispersion plates 24, 34, 44. 47, respectively, and the riser 11 and the first and second gas discharge pipes 22 and 32 each of the first, second, and third thermometers 26 and 36 that detect abnormal temperature rise changes and pressure differences. (46) and open operation by detection signals of the first, second and third discharge pipe pressure gauges 25, 35, 45 and the first, second, and third low pressure differential pressure gauges 27, 37, 47. The first, second, and third nitrogens having first, second, and third open / close valves (28, 38, 48) to be supplied into the preheating furnace (40), the preliminary reduction passage (30), and the final reduction passage (20). Gasra Back gas supply apparatus for the flow reduction reactor characterized in that the phosphorus (29) (39) (49) is connected. The method of claim 1, The first, second, and third low pressure differential pressure gauges 27, 37, and 47 are formed when the nozzles of the first, second, and third dispersion plates 24, 34, 44 are blocked by dust and falling clouds. When detecting that the pressure difference in the upper and lower portions of the first, second, and third dispersion plates 24, 34, 44 rapidly increases to 300 mmbar or more, the corresponding reactors 20, 30, 40 lower Open the first, second and third open / close valves 28, 38, and 48 to supply nitrogen gas through the first, second, and third nitrogen gas lines 29, 39, 49 to the side; A backup gas supply device for a flow reduction reactor, characterized in that for generating a detection signal for closing the first, second and third control valves (21) (31) (41). The method of claim 1, The first, second and third discharge pipe differential pressure gauges 25, 35 and 45 are pressures between the inlet and outlet ends of the first, second and third ore discharge pipes 23, 33 and 43 during the reducing gas backflow. When detecting that the difference sharply drops below 100 mmbar, nitrogen gas is supplied through the first, second, and third nitrogen gas lines 29, 39, 49 to the lower portions of the corresponding reactors 20, 30, 40. Open the first, second and third open / close valves 28, 38, and 48 so as to generate a detection signal for closing the first, second, and third control valves 21, 31, 41; Back-up gas supply apparatus for the fluidized reduction furnace, characterized in that. The method of claim 1, The first, second, and third thermometers 26, 36, and 46 are temperature change values at which gas temperatures detected by the first, second, and third ore discharge pipes 23, 33, 43 are set when the reducing gas flows back. When rapidly increasing above 50 DEG C, the first and second nitrogen gas lines 29, 39 and 49 are supplied to the lower side of each of the corresponding reactors 20, 30 and 40 to supply nitrogen gas. It is characterized by generating a detection signal for opening the first and second opening and closing valves 28, 38, and 48, and closing the first, second and third adjustment valves 21, 31, and 41. Back-up gas supply device for the flow reduction path. The method of claim 1 The first, second and third control valves 21, 31 and 21 are initially filled with ore gas in the preheating, preliminary and final reduction paths 20, 30 and 40 when filling the ore. The ore is kept closed so that only the bottoms of the first, second, and third dispersion plates 24, 34, 44 of the reactors 20, 30, 40 can flow. ), And the height of the fluidized bed in the preheating furnace, the preliminary reduction furnace, the final reduction passages 20, 30, and 40 is gradually increased, so as to form a smooth fluidized bed. (33) (43) As it rises up to the inlet end, it is gradually opened to discharge the ore to secure the fluidized bed of the preheating, preliminary and final reduction paths (20, 30, 40) Back-up gas supply device of the reduction furnace.