KR100362678B1 - Device for preventing material flow blockage of fluidized bed reactor in ironmaking process using non-coking coal and fine ore - Google Patents

Abstract

In the present invention, the ore flow between the multi-stage flow reduction reactors is caused by the fluctuation of the flow rate of the high temperature reducing gas discharged from the melting gasification furnace and supplied to the flow reduction path installed in the multistage due to the change of operating conditions in the melting gasifier. The present invention relates to an apparatus for preventing stagnation of ore flow in a flow reducing furnace in an improved molten iron manufacturing process to prevent excessive stagnation.

First and second connection pipes 11 and 12 and the first and second connection pipes 2 and 3 respectively connecting between the first and second conduits 11 and 12; First and second open / close valves (4) (5) for opening and closing the gas flow through the first and second connection pipes (2) and (3); First and second nitrogen purging conduits (6a) (6b) (7a) (7b) connected to the front and rear ends of the first and second open / close valves (4) and (5), respectively; The first and second conduits 11 and 12 adjacent to the preliminary reduction path C and the final reduction path D so that pressure fluctuations imposed on the first and second conduits 11 and 12 can be detected at any time. First and second pressure gauges 8 and 9 provided at each end portion; A controller for controlling the first and second open / close valves (4) and (5) based on values detected by the first and second pressure gauges (8) and (9); Provided is an apparatus for preventing stagnation of ore flow in a flow reduction furnace in a process.

Description

DEVICE FOR PREVENTING MATERIAL FLOW BLOCKAGE OF FLUIDIZED BED REACTOR IN IRONMAKING PROCESS USING NON-COKING COAL AND FINE ORE}

The present invention relates to an apparatus capable of preventing stagnation and backflow of ore flow in a fluid reduction furnace in a molten iron manufacturing process using ordinary coal and fine iron ore. More specifically, the present invention relates to a molten gasification furnace. Improved molten iron production to prevent excessive stagnation of ore flow between the multi-stage flow reduction reactors in the event of rapid fluctuations in the flow rate of high-temperature reducing gas discharged from the gasifier to the multistage flow reduction reactor. The present invention relates to a device for preventing ore flow stagnation in a flow reduction furnace.

In general, the blast furnace method, which constitutes a large scale of molten iron production equipment, has a certain strength or higher due to the characteristics of the reactor, and requires a raw material having a particle size to ensure the ventilation of the furnace. As a carbon source used as a fuel and a reducing agent, It relies on coke processed specific raw coal, and as an iron source, it mainly depends on sintered ore which has undergone a series of bulking processes.

Accordingly, the current blast furnace method necessarily involves preliminary processing of raw materials such as coke manufacturing facilities and sintering facilities. The competitiveness of the current blast furnace law is rapidly being encroached by the enormous investment costs for environ- mental pollution prevention facilities to overcome the regulations.

In order to cope with the above situation, countries around the world directly use general coal as fuel and reducing agent, and as a source of iron, develop new steelmaking process to manufacture molten iron by using ferrous ore, which occupies more than 80% of the world's ore production. Spurs on

In the molten iron manufacturing equipment which uses the conventional general coal and spectroscopy directly related to this technique, AT2092 / 92 etc. which are patent-pending in Austria are known.

According to the known technique, as shown in FIG. 1, a three-stage flow reduction reactor such as a preheating furnace (B), a preliminary reduction reactor (C), and a final reduction reactor (D) and a coal packed bed are formed. It consists of a molten gasifier (A), the spectroscopy at room temperature continuously charged into the preliminary reduction reactor (C) of the upper stage while passing through the three-stage flow reduction reactor (B) (C) (D) By contacting with a high temperature reducing air stream supplied from a melt gasifier (A), it is converted into a high temperature reducing spectrometer which is heated up and reduced by more than 90%, and discharged, while the reduced reducing spectroscopy is formed with the coal packed layer. The molten gasifier A is continuously charged into the molten gasifier A through the reducing light supply line 24 and melted in the coal packed bed to be turned into molten iron and discharged to the outside of the molten gasifier A.

In addition, in the molten gasifier (A), the bulky coal is continuously supplied from the upper part of the furnace to form a coal filling layer having a constant height inside the furnace, and a plurality of air holes formed at the bottom of the outer wall into the coal filling layer. Oxygen is blown in through the coal in the coal packed bed, and the combustion gas rises through the bed and is converted to a high temperature reducing air and then discharged to the outside of the molten gasifier (A). It is fed to the flow reduction reactor.

In addition, the movement between the preheating furnace (B), the preliminary reduction reactor (C), and the final reduction reactor (D) of the ore passing through the three-stage flow reduction reactor is the first and second ore flow conduits connecting the adjacent furnaces (hereinafter, It is made through (11) (12), the high temperature reduction formed in the flow reduction path of the lower flow path from the lower flow reduction path by the upper and lower pressure difference in the conduit (11, 12) Ore flows formed from the flow reduction path at the top to the flow reduction path at the bottom by the flow of gas and gravity are formed to cross each other.

On the other hand, the high temperature is supplied to the three-stage flow reduction path (B) (C) (D) through the first, second, third gas supply lines 21, 22, 23 from the melt gasifier (A) The reducing gas is produced by combustion and gasification of ordinary coal, and the amount of generation may vary considerably depending on the characteristics of raw coal and operation abnormalities. According to the results of the operation so far, the high temperature in the molten gasifier A In the severe case, the fluctuation range of the reducing gas amount is about 20 to 30% of the average amount produced, and the above extreme fluctuation occurs within a short time of about a few minutes.

This phenomenon is commonly referred to as a pressure peak, and as the amount of the hot reducing gas supplied to the preheating furnace (B) and the preliminary reduction reactor (C) side is increased rapidly in a short time. The first and second gas supply lines 21 and 22 connecting the same, the amount of supply of reducing gas to the preheating furnace (B) and the preliminary reduction reactor (C) side increases, and the spectroscopic discharge is the first flow , The amount of reducing gas rising from the bottom through the second conduit (11, 12) is also rapidly increased.

The rapid formation of the gas flow rate in the first and second conduits 11 and 12 as the amount of the high temperature reducing gas rising through the first and second conduits 11 and 12 is increased Ore flow is formed to intersect with the gas flow, and in excessive cases, the flow of the ore flow is reversed.

In addition, the stagnation of the ore flow may continue for a considerable time even after the pressure peak is extinguished, and not only inhibits the smooth operation of the three-stage flow reduction reactor, but also severely preheats (B), preliminary Fully blocking the ore flow between the reduction furnace (C) and the final reduction furnace (D) caused a serious plant accident that would shut down the operation.

Accordingly, the present invention has been made to solve the above problems, the object of which is to detect when the pressure peak occurs, by opening the branch line which can branch the reducing gas to the exhaust side of the ore flow in the conduit through which the ore flows. In the molten iron manufacturing process using ordinary coal and iron ore that can prevent the congestion in advance to provide a device for preventing stagnation of ore flow in the flow reduction furnace.

1 is an overall configuration diagram showing an ore flow stagnation prevention device of a flow reducing furnace in a molten iron manufacturing process using a coal and a powdered iron ore according to the present invention,

FIG. 2 is a graph showing the correlation between time difference and differential pressure causing congestion and backflow of ore flow in the second ore flow conduit during pressure peak occurrence; FIG.

Figure 3 is a graph showing the correlation between the differential pressure change and the time in the second ore flow conduit at the time of the pressure peak employing the present invention.

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

2 ..... 1st connector 3 ..... 2nd connector

4 ..... 1st Opening Valve 5 ..... 2nd Opening Valve

6a, 6b ... first nitrogen purging conduit 7a, 7b ... second nitrogen purging conduit

8 ..... 1st pressure gauge 9 ... 2nd pressure gauge

11 .... First Conduit 12 ..... Second Conduit

A ..... Melt Gasifier B ... Preheating Furnace

C ..... Preliminary Reduction C ...

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

A preheating furnace connected to the melt gasifier and the first, second and third gas supply lines, a three-stage flow reducing furnace consisting of a preliminary reduction path and a final reduction path, and a collecting device connected to the preheating furnace and an exhaust pipe; In the facility for manufacturing molten iron having a first ore flow conduit connecting between the preheating furnace and the preliminary reduction path and the second ore flow conduit connecting between the preliminary reduction path and the final reduction path,

First and second connection pipes connecting between the first and second conduits and the exhaust pipe, respectively; First and second open / close valves for opening and closing a gas flow through the first and second connection pipes; First and second nitrogen purging conduits respectively connected to the front and rear ends of the first and second open / close valves; First and second pressure gauges installed at each end of the first and second conduits close to the final reduction path so as to detect pressure fluctuations imposed on the first and second conduits from time to time; And a controller for controlling the opening and closing of the first and second opening / closing valves based on the values detected by the first and second pressure gauges. By providing a device for preventing ore flow stagnation.

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

1 is an overall configuration diagram showing an ore flow stagnation prevention device of a flow reducing furnace in a molten iron manufacturing process using ordinary coal and powdered iron ore according to the present invention, as shown in FIG. The first conduit 11 is installed between the preheating furnace (B) and the preliminary reduction path (C) at the time of peak occurrence, and the second conduit (12) is installed between the preliminary reduction path (C) and the final reduction path (D). It is to prevent ore flow from stagnation or backflow within.

That is, the first connecting pipe (2) having one end connected to the first conduit (11) has an exhaust pipe (13) and the other end for guiding the reducing gas passed through the preheating furnace (B) to the collecting device (E). Is connected in communication, the middle of the length of the first connecting pipe (2) is equipped with a first opening and closing valve (4) so as to properly open and close the gas flow therethrough, the front and rear of the first opening and closing valve (4) is closed In operation, a first nitrogen purging conduit 6a for injecting nitrogen gas into the first connecting pipe 2 connected to the exhaust pipe 13 and a first conduit for supplying ferrous iron ore to the preliminary reduction path C. Another first nitrogen purging conduit 6b for injecting purge nitrogen gas to the preliminary reduction path C side to prevent the inflow of fine ore into the first connecting pipe 2 connected to (11), respectively. On the other hand, the first nitrogen purging conduits 6a and 6b are provided with control valves 16a and 16b to properly control the supply of nitrogen gas. Respectively, it is mounted.

The first pressure gauge 8, which detects the pressure applied to the first conduit 11 from time to time and measures the pressure inside the tube, is located near the distal end of the first conduit 11 close to the preliminary reduction path C. And a controller in which the pressure value measured by the first pressure gauge 8 is transmitted and received, and the controller calculates a state in which the pressure fluctuates in the first conduit 11 and based on the occurrence of the pressure peak. By determining whether the first opening and closing valve 4 is opened or closed to control it.

On the other hand, between the preliminary reduction path (C) and the final reduction path (D) to form a second connecting pipe 3 in the same manner as above, one end of the second connecting pipe (3) is the exhaust pipe (13) And, the other end is in communication with the second conduit 22, respectively, and the second opening and closing valve (5) for opening and closing the gas flow through the middle of the length of the second connecting pipe (3) is mounted, the second opening and closing The second nitrogen purging conduit 7a so as to inject purging nitrogen gas to the side connected to the exhaust pipe 13 and to the side connected to the final reduction path D during the closing operation before and after the valve 5, respectively. Each of 7b is connected to each other, and the second nitrogen purging conduits 7a and 7b are respectively provided with control valves 17a and 17b for controlling the supply of nitrogen gas.

Then, the second pressure gauge (9) for detecting the pressure applied to the second conduit (12) from time to time to measure the pressure inside the tube near the end of the second conduit (12) close to the final reduction path (D) And a controller in which the pressure value measured by the second pressure gauge 9 is transmitted and received, and the controller calculates a state in which the pressure fluctuates in the first conduit 11 and based on the occurrence of the pressure peak. The first and second pressure gauges (8) and (9) are connected to the first and second open / close valves (4) and (5). It is electrically connected to each other, and is electrically connected to a controller for controlling opening and closing of the first and second open / close valves 4 and 5, respectively.

Here, the first and second connection pipes (2) (3) and the first and second connection pipes (11, 12) are connected to each other (T1) (T2) when the pressure peak occurs in the first connection pipe (2) In order to prevent the introduction of the iron ore into the) it is preferable to be provided at the same position or higher than the maximum height of the ore flow formed in the preliminary reduction path (C).

The first and second connection pipes 2 and 3 are made of heat resistant steel that can withstand high temperature reducing gas sufficiently, and the diameters of the first and second connection pipes 2 and 3 are first and second. It is preferred to be provided with a size 1/2 of the conduits 11 and 12.

Referring to the operation and effect of the present invention having the configuration as described above are as follows.

If the pressure peak does not occur due to the normal ore reduction process in the preheating furnace (B), preliminary reduction furnace (C) and final reduction furnace (D), the first and second connection pipes (2) and (3) are mounted. Since the first and second open / close valves 4 and 5 are kept closed, the high-temperature reducing gas supplied from the molten gasifier A is connected to the first and second gas supply lines 21 and 22. Through the final reduction path (C), the preliminary reduction path (C) and the preheating furnace (B) continuously to form a normal gas flow flowing to the exhaust pipe (13).

In the normal operation, the first and second nitrogen purging conduits 6a, 6b, 7a, and 7b open and close the control valves 16a, 16b, 17a, and 17b, respectively. Nitrogen gas is supplied into the first and second connection pipes (2) and (3) at the boundary between the on / off valves (4) and (5), respectively, so that the exhaust pipe (13) through which the exhaust gas containing pulverized coal flows and the first through which the iron-iron ore flows. The second conduit (11) (12) to prevent the inflow of foreign matter and fine ore into the interior of the first and second connection pipe (2) (3) connected between.

On the other hand, when excessive high temperature reducing gas flows into the first conduit 11 due to the pressure peak generated in the melt gasifier A, the first pressure gauge 8 mounted to the distal end of the first conduit 11 Detects this, and the detected pressure signal is transmitted to the controller side, and calculates the pressure fluctuation speed value at which the received pressure value changes for a predetermined time to determine whether the first opening / closing valve 4 is opened or closed. do.

Here, the first opening / closing valve 4 is opened when the pressure variation speed value measured by the first pressure gauge 8 is 0.05 bar / sec or more, which is a set reference value.

As described above, when the value of the pressure fluctuation velocity detected at the distal end of the first conduit 11 is greater than or equal to the set reference value, the first opening / closing valve 4 is opened to exhaust the exhaust pipe 13 and the first connecting pipe 2. ) And the first conduit 11 are in communication with each other, so that a large portion of the hot reducing gas flowing into the distal end of the first conduit 11 in a large amount is increased from the first conduit 11 to the first conduit 2. Branched to the exhaust pipe 13 through. As a result, it is possible to prevent the formation of an excessive flow velocity reducing gas flow that is opposed to the ore flow in the first conduit 11, so that it has flowed to the preliminary reduction path C in the first conduit 11. Ore flow is prevented from stagnation in the tube or backflow to the preheating furnace (B) side to ensure a stable operation.

As described above, when an excessive amount of high temperature reducing gas flows into the second conduit 12 side due to the pressure peak generated in the molten gasifier A, the second end of the second conduit 12 is mounted. The pressure gauge 9 detects this, and the detected signal is transmitted and calculated to the controller side to determine whether the second open / close valve 5 is opened or closed.

Here, the second open / close valve 5 is opened when the pressure variation speed value measured by the second pressure gauge 9 is 0.03 bar / sec or more, which is a set reference value.

As described above, when the value of the pressure fluctuation speed detected at the distal end of the second conduit 12 is formed to be greater than or equal to the set reference value, the second open / close valve 5 is opened to exhaust the exhaust pipe 13 and the second connection pipe 3. ) And the second conduit 12 are in communication with each other, a substantial portion of the hot reducing gas flowing into the distal end of the second conduit 12 through the second conduit 12 from the second conduit 12 Branched to the exhaust pipe (13). As a result, it is possible to prevent the formation of an excessive flow velocity reducing gas flow that is opposed to the ore flow in the second conduit 12, so that it has flowed to the final reduction path D in the second conduit 12. Ore flow is prevented from stagnation in the pipe or backflow to the preliminary reduction path (C) to ensure a stable operation.

FIG. 2 is a graph showing the correlation between the time difference and the differential pressure which causes congestion and backflow of ore flow in the second ore flow conduit upon pressure peak occurrence, which is caused by the congestion and backflow of ore flow. Shows that the pressure difference between the top and the end increases rapidly when the c) is blocked.

On the other hand, Figure 3 is a graph showing the relationship between the differential pressure change in the second ore flow conduit and the time when the pressure peak occurs by employing the present invention, which is a high temperature introduced into the second conduit 12 when the pressure peak occurs By branching and discharging the upper portion of the reducing gas from the second conduit 12 to the exhaust pipe 13 through the second connecting pipe 3, the differential pressure value is increased to some extent and then decreased again.

Therefore, it is a preheating furnace (B) and a preliminary reduction reactor (C), between the preliminary reduction reactor (C) and the final reduction reactor (D) in a three-stage flow reduction reactor for producing molten iron using ordinary coal and fine iron ore. It has been shown that effective ore flow can always be formed in the first and second conduits 11 and 12 by effectively preventing ore flow congestion and backflow.

According to the present invention as described above, in the process of manufacturing molten iron using ordinary coal and fine iron ore, the high temperature reduction discharged from the smelting furnace by the fluctuation of operating conditions in the molten gasifier and supplied to the three-stage flow reduction reactor side Detects and measures the pressure fluctuations in the first and second conduits connecting the preheating and preliminary reactors and between the preliminary and final reactors when pressure peaks occur. By controlling the opening and closing of the first and second connection pipes in communication with the exhaust pipe, it is possible to prevent congestion and reverse flow of the photosphere due to excessive reducing gas flow in the first and second conduits through which the ore flows. It is possible to secure smooth operation and maintain stable flow reduction operation.

Claims (4)

It consists of a preheating furnace (B), a preliminary reduction reactor (C) and a final reduction reactor (D) connected through the melt gasifier (A) and the first, second and third gas supply lines (21) (22) and (23). A three-stage flow reduction path, a collecting device (E) connected through the preheating furnace (B) and the exhaust pipe (13), and a first ore connecting between the preheating furnace (B) and the preliminary reduction passage (C) In the facility for manufacturing molten iron having a flow chart tube 11 and the second ore flow conduit 12 connecting between the preliminary reduction path (C) and the final reduction path (D), First and second connection pipes (2) and (3) connecting between the first and second conduits (11, 12) and the exhaust pipe (13), respectively; First and second open / close valves (4) (5) for opening and closing the gas flow through the first and second connection pipes (2) and (3); First and second nitrogen purging conduits (6a) (6b) (7a) (7b) connected to the front and rear ends of the first and second open / close valves (4) and (5), respectively; The first and second conduits 11 and 12 adjacent to the preliminary reduction path C and the final reduction path D so that pressure fluctuations imposed on the first and second conduits 11 and 12 can be detected at any time. First and second pressure gauges 8 and 9 provided at each end portion; And a controller for controlling the opening and closing of the first and second opening / closing valves (4) and (5) based on the values detected by the first and second pressure gauges (8) and (9). Preventing stagnation of ore flow in a fluid reduction furnace in molten iron manufacturing process using iron ore. The method of claim 1, The first and second connection pipes (2) (3) and the first and second conduits (11, 12) in communication with each other (T1) (T2) into the first connection pipe (2) when the pressure peak occurs Flow in the process of manufacturing molten iron using coal and iron ore, characterized in that provided in the same position or higher than the maximum height of the ore flow formed in the preliminary reduction path (C) to prevent the inflow of the iron ore Preventing ore flow stagnation in the reduction furnace. The method of claim 1, The first and second connection pipes (2) and (3) are made of heat-resistant steel that can withstand high temperature reducing gas sufficiently, and the diameter of the first and second connection pipes (2) and (3) is the first and second conduits ( 11) (12) A device for preventing stagnation of ore flow in a flow reducing furnace in a molten iron manufacturing process using plain coal and powdered iron ore, characterized in that the size of 1/2. The method of claim 1, The first open / close valve 4 is opened when the pressure change speed value measured by the first pressure gauge 8 is 0.05 bar / sec or more, which is a set reference value, and the second open / close valve 5 is operated by the second pressure gauge. An apparatus for preventing stagnation of ore flow in a flow reducing furnace in a molten iron manufacturing process using ordinary coal and ferrous ore, characterized in that the opening operation is performed when the pressure variation speed value measured in (9) is 0.03 bar / sec or more.