KR102176353B1 - Apparatus and method for dust recyle - Google Patents

Abstract

The dust recycling apparatus of the melting furnace includes a weighing unit, a dust feeder, and an oxygen supply unit. The weight measuring unit is installed in the dust bin and measures the weight of dust accumulated in the dust bin. The dust feeder is installed in the conveying pipe connecting the exit of the dust bin and the burner, and controls the amount of dust discharged in conjunction with the increase in dust per unit time of the dust bin. The oxygen supply unit is connected to the burner's oxygen inlet and controls the amount of oxygen intake of the burner in conjunction with the dust discharge per unit time of the dust feeder.

Description

Dust recycling apparatus and method of melting furnace {APPARATUS AND METHOD FOR DUST RECYLE}

The present invention relates to a technology for manufacturing molten iron, and more particularly, to a dust recycling apparatus and method for recovering dust in a reducing gas discharged from a melting furnace and re-injecting it into the melting furnace.

In the FINEX process, coal briquettes formed from powdered coal into lumps and high-temperature compressed iron formed by compressing reduced iron ore into lumps are charged into the melting furnace, and pure oxygen is injected to create a high-temperature reducing atmosphere. Then, the high-temperature compression molded iron is melt-reduced inside the melting furnace to form molten iron.

Since coal briquettes manufactured at room temperature have lower strength at high temperatures than coke manufactured at high temperatures, coal briquettes charged in the melting furnace are differentiated to generate dust, and the dust is discharged to the outside of the melting furnace together with the reducing gas. The high-temperature compression molding railway is partially differentiated inside the melting furnace and discharged to the outside of the melting furnace along with the reducing gas. Therefore, the dust in the reducing gas discharged from the melting furnace has high iron and carbon components.

The cyclone connected to the melting furnace separates the reducing gas and dust, and the dust separated from the cyclone is fed back into the melting furnace through a transfer pipe. At this time, a burner that reacts dust and oxygen is installed in the transfer pipe. The dust melts by reaction with oxygen and is agglomerated by sticking to each other, and it is possible to be recycled by being settled on the furnace bed only when the particle size is increased by agglomeration.

The burner must be heated to a minimum level to allow dust to aggregate. If the dust heating temperature of the burner is excessively low, the dust cannot be aggregated, and the dust injected into the melting furnace is discharged together with the reducing gas, thereby increasing the amount of dust in the reducing gas, thereby causing clogging of the conveying pipe. Conversely, if the dust heating temperature of the burner is excessively high, it may cause a problem that the molten dust adheres to the inner wall of the conveying pipe or the wall of the melting furnace.

An object of the present invention is to provide an apparatus and method for recycling dust in a melting furnace capable of increasing dust recycling efficiency and melting furnace efficiency by properly maintaining a dust heating temperature of a burner.

The dust recycling apparatus of the melting furnace according to an embodiment of the present invention includes a weighing unit, a dust feeder, and an oxygen supply unit. The weight measuring unit is installed in a dust bin that receives and stores dust from the cyclone, and measures the weight of the dust accumulated in the dust bin. The dust feeder is installed in the conveying pipe connecting the exit of the dust bin and the burner, and controls the amount of dust discharged in conjunction with the increase in dust per unit time of the dust bin. The oxygen supply unit is connected to the burner's oxygen inlet and controls the amount of oxygen intake of the burner in conjunction with the dust discharge per unit time of the dust feeder.

The dust discharge per unit time of the dust feeder may be the same as the dust increase per unit time of the dust bin, and the oxygen injection amount of the oxygen supply unit may be proportional to the dust discharge per unit time of the dust feeder.

The weight measurement unit may be composed of either a load cell or a strain gauge. Flexible hoses can be installed at the inlet and outlet of the dust bin respectively. The dust feeder can be composed of either a rotary feeder or a screw feeder.

The weight measurement unit, the dust feeder, and the supply unit may be electrically connected to the control unit, and the control unit may control the operation of the dust feeder and the oxygen supply unit according to the measurement result of the weight measurement unit.

When the weight of the dust measured by the weight measurement unit is greater than or equal to the reference weight, the control unit can operate the dust feeder. The dust discharge per unit time of the dust feeder may be equal to the increase in dust per unit time of the dust bin.

The control unit may include a memory storing information on a temperature condition capable of coagulating dust to an appropriate size according to a composition of dust and an amount of discharge per unit time and an oxygen injection amount for implementing the temperature condition.

The control unit loads information on the oxygen injection amount from the memory according to the composition of the dust and the discharge amount per unit time of the dust feeder, and controls the operation of the oxygen supply unit so that oxygen is injected into the burner as much as the loaded oxygen injection amount.

The dust recycling method of the melting furnace according to an embodiment of the present invention includes the steps of measuring the weight of dust accumulated in the dust bin by the weight measuring unit, discharging the dust from the dust feeder toward the burner, and the oxygen supply unit And supplying oxygen to the oxygen inlet of the. The dust discharge per unit time of the dust feeder is the same as the increase of dust per unit time of the dust bin, and the oxygen injection amount of the oxygen supply part is proportional to the dust discharge per unit time of the dust feeder.

The weight measurement unit, the dust feeder, and the oxygen supply unit may be electrically connected to the control unit, and the control unit may operate the dust feeder when the weight of the dust measured by the weight measurement unit is more than the reference weight.

The control unit may include a memory storing information on a temperature condition capable of coagulating dust to an appropriate size according to a composition of dust and an amount of discharge per unit time and an oxygen injection amount for implementing the temperature condition.

The control unit loads information on the oxygen injection amount from the memory according to the composition of the dust and the discharge amount per unit time of the dust feeder, and controls the operation of the oxygen supply unit so that oxygen is injected into the burner as much as the loaded oxygen injection amount.

According to the present invention, a certain amount of dust can be uniformly injected into the melting furnace, and the amount of oxygen capable of generating a flame of an appropriate temperature according to the input amount of the dust can be automatically injected into the burner. Therefore, the dust injected into the melting furnace may be aggregated to an appropriate particle size by the flame of the burner and settled on the melting furnace bed, and the recycling efficiency and the melting furnace efficiency of the dust may be improved.

1 is a block diagram of a chartered iron manufacturing facility equipped with a dust recycling device according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a burner in the molten iron manufacturing facility shown in FIG. 1.
FIG. 3 is a right side view of a burner in the molten iron manufacturing facility shown in FIG. 1.
4 is a block diagram showing a phenomenon of agglomeration of dust by a burner in the molten iron manufacturing facility shown in FIG.
5 is a graph showing a change in weight of dust accumulated in a dust bin and a dust discharge amount of a dust feeder.
6 is a graph showing the amount of dust discharged from the dust feeder and the oxygen injection amount of the oxygen supply unit.
7 is a flow chart showing a dust recycling method in a melting furnace according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the present invention. The present invention may be implemented in various different forms, and is not limited to the embodiments described herein.

1 is a block diagram of a chartered iron manufacturing facility equipped with a dust recycling device according to an embodiment of the present invention.

Referring to FIG. 1, the molten iron manufacturing facility receives and stores the smelting furnace 10, the cyclone 20 separating the dust from the reducing gas discharged from the melting furnace 10, and the dust separated from the cyclone 20. It includes a dust bin 30, a transfer pipe 40 connecting the outlet of the dust bin 30 and the melting furnace 10, and a burner 50 installed at the end of the transfer pipe 40. .

The molten iron manufacturing facility is a FINEX facility, in which coal briquettes are charged instead of coke in the melting furnace 10, and high-temperature compression molded iron is charged instead of the sintering ore. In addition, pure oxygen is blown into the melting furnace 10 through the air blower to make the inside of the melting furnace 10 a high-temperature reducing atmosphere. The melting furnace 10 produces molten iron by melting and reducing the high-temperature compression molded iron.

The reducing gas discharged from the melting furnace 10 contains dust, and the dust contains a large amount of iron and carbon components. In order to recycle dust, the cyclone 20 separates the reducing gas and the dust, the dust bin 30 receives and stores the dust from the cyclone 20, and the dust discharged from the dust bin 30 is transported. It is introduced into the melting furnace 10 through the pipe 40. At this time, the dust introduced into the melting furnace 10 is heated by the burner 50 to melt and become tangled and aggregated.

2 and 3 are a cross-sectional view and a right side view of a burner in the molten iron manufacturing facility shown in FIG. 1, respectively.

1 to 3, the burner 50 has a pipe shape made of metal, and dust is blown into the melting furnace 10 through the central hole 51. The dust is carried by a carrier gas, for example nitrogen gas. Inside the burner 50, a cylinder-shaped oxygen inlet 52 surrounding the central hole 51 in a concentric circle shape is located.

The oxygen inlet 52 has a diameter that gradually decreases at the end of the burner 50 located inside the melting furnace 10 while maintaining a constant diameter. As a result, a flame is generated by combustion of oxygen and furnace gas inside the melting furnace 10, and the flame is overlapped with the blown dust to heat the dust.

4 is a block diagram showing a phenomenon of agglomeration of dust by a burner in the molten iron manufacturing facility shown in FIG. 1.

Referring to FIG. 4, dust passing through the burner 50 is agglomerated by a flame, and dust agglomerated above a certain size is seated on the furnace bed 11 and recycled. On the other hand, dust that has not been aggregated to a certain size or more cannot be settled on the furnace bed 11 and is blown away and discharged to the outside of the furnace together with the reducing gas. The higher the ratio of the dust aggregated to an appropriate size and settled on the furnace bed 11, the higher the efficiency of the melting furnace 10.

Oxygen is responsible for the supply of heat for heating the dust in the burner 50, and in order for the burner 50 to maintain an appropriate heating temperature, the ratio of the amount of dust and the blown oxygen must be constant. Referring to FIG. 1 again, the dust recycling device 60 discharges the dust into the transfer pipe 40 according to the increase in dust per unit time of the dust bin 30, and adjusts the oxygen injection amount in proportion to the dust discharge per unit time. It consists of a composition.

Specifically, the dust recycling device 60 includes a weight measuring unit 61 installed in the dust bin 30 to measure the weight of the dust, and a dust feeder installed in the transfer pipe 40 to control the discharge of dust. It includes a feeder (62) and an oxygen supply unit (63) connected to the burner (50) to control the oxygen injection amount of the burner (50).

The weight measurement unit 61, the dust feeder 62, and the oxygen supply unit 63 are electrically connected to the control unit 70, and the control unit 70 is the dust feeder 62 according to the measurement result of the weight measurement unit 61. And control the operation of the oxygen supply unit (63).

The weight measurement unit 61 may be composed of a load cell or a strain gauge, and measures the weight of the dust accumulated in the dust bin 30 in real time. At this time, a flexible hose may be installed at the inlet and outlet of the dust bin 30 so that a structural load is applied to the weight measurement unit 61 so that an error does not occur in measurement.

The flexible hose is a first flexible hose 81 connecting the dust outlet of the cyclone 20 and the inlet of the dust bin 30, and a first flexible hose 81 connecting the outlet of the dust bin 30 and the transfer pipe 40. It consists of 2 flexible hoses (82). As flexible flexible hoses 81 and 82 are installed instead of metal pipes at the inlet and outlet of the dust bin 30, the structural load can be excluded from the load applied to the weight measurement unit 61, so that the weight measurement unit 61 ) Can increase the accuracy.

The transfer pipe 40 is composed of a first transfer pipe 41 extending downward from the second flexible hose 82 and a second transfer pipe 42 connected to the first transfer pipe 41 and extending in a horizontal direction. Can be. The second transfer pipe 42 may have an inclined height that decreases toward the melting furnace 10 for efficient dust transfer. The dust feeder 62 is installed in the first conveying pipe 41 and may be installed at an end of the first conveying pipe 41 facing the second flexible hose 82.

The dust feeder 62 may be composed of any one of a rotary feeder having a rotating plate or a rotating drum, and a screw feeder having a transfer screw. The rotary feeder can control the discharge of dust by adjusting the rotational speed of the rotating plate or the rotating drum, and the screw feeder can control the rotational speed of the conveying screw.

When the weight of the dust measured by the weight measurement unit 61 is greater than or equal to the reference weight, the control unit 70 operates the dust feeder 62 by outputting a control signal to the dust feeder 62. 5 is a graph showing a change in weight of dust accumulated in a dust bin and a dust discharge amount of a dust feeder.

1 and 5, the weight of the dust in the dust bin 30 gradually increases and then reaches the reference weight w0, and the time point t0 at which the reference weight w0 reaches the dust feeder 62 It becomes the reference point of operation.

At this time, the increase amount of dust per unit time (weight increase amount) is substantially constant, although there is a small difference, and the dust discharge amount per unit time of the dust feeder 62 is set to be equal to the dust increase amount per unit time of the dust bin 30. Therefore, after the dust feeder 62 starts to operate, the weight of the dust in the dust bin 30 is maintained equal to the reference weight w0.

Referring back to FIGS. 1 to 3, the oxygen supply unit 63 is connected to the oxygen inlet 52 of the burner 50 to supply oxygen to the oxygen inlet 52. The oxygen supply unit 63 may include an oxygen tank and a flow controller, and the amount of oxygen supplied to the burner 50 may be precisely adjusted by the operation of the flow controller. 6 is a graph showing the amount of dust discharged from the dust feeder and the oxygen injection amount of the oxygen supply unit.

1 and 6, the oxygen injection amount of the oxygen supply unit to the burner 50 is set to be proportional to the dust discharge amount per unit time of the dust feeder 62. In the memory of the control unit 70, information on a temperature condition capable of condensing the dust into an appropriate size according to various conditions such as the composition of dust and the amount of discharge per unit time, and information on the oxygen injection amount for realizing this temperature condition are stored in advance. .

The control unit 70 loads information on the corresponding oxygen injection amount in connection with the dust discharge amount per unit time of the dust feeder 62, and oxygen is injected into the burner 50 as much as the loaded oxygen injection amount q0. Controls the operation of the supply unit 63. When the dust discharge amount of the dust feeder 62 increases, the oxygen injection amount increases, and when the dust discharge amount of the dust feeder 62 decreases, the oxygen injection amount decreases.

As described above, the dust recycling device 60 of this embodiment discharges dust from the dust feeder 62 by the amount of dust accumulated in the dust bin 30, and controls the amount of oxygen supplied to the burner 50 in proportion to the dust discharge. It consists of a configuration. Therefore, the dust injected into the melting furnace 10 may be aggregated to an appropriate particle size by the flame generated from the burner 50 and settled on the melting furnace bed 11, thereby increasing the recycling efficiency of dust.

7 is a flow chart showing a dust recycling method in a melting furnace according to an embodiment of the present invention.

Referring to FIGS. 1 and 7, the dust recycling method of the melting furnace includes a first step (S10) of measuring the weight of the dust in the weighing unit 61, and the second step of discharging the dust by operating the dust feeder 62. And a third step (S30) of generating a flame for agglomerating dust by blowing oxygen from the oxygen supply unit 63 to the burner 50.

In the first step (S10), the weight measurement unit 61 may be composed of a load cell or a strain gauge, and measures the weight of the dust accumulated in the dust bin 30 in real time, and the measurement result to the control unit 70 Print. Flexible flexible hoses 81 and 82 are installed at the inlet and outlet of the dust bin 30 instead of a rigid metal tube, so that the accuracy of the weighing unit 61 can be improved.

In the second step (S20), the dust feeder 62 may be composed of any one of a rotary feeder and a screw feeder. The control unit 70 operates the dust feeder 62 when the weight of the dust measured by the weight measurement unit 61 is greater than or equal to the reference weight. The dust discharge amount per unit time of the dust feeder 62 is equal to the increase amount of dust per unit time of the dust bin 30. Therefore, when the dust feeder 62 is operated, the weight of the dust in the dust bin 30 is maintained equal to the reference weight.

In the third step (S30), the oxygen supply unit 63 may be composed of an oxygen tank and a flow rate controller, and supplies oxygen to the oxygen inlet 52 of the burner 50. The oxygen injection amount of the oxygen supply unit 63 to the burner 50 is proportional to the dust discharge amount per unit time of the dust feeder 62.

The memory of the control unit 70 stores information on a temperature condition capable of condensing dust into an appropriate size and an oxygen injection amount for implementing this temperature condition. The control unit 70 loads the oxygen injection amount corresponding to the dust discharge amount per unit time of the dust feeder 62, and controls the operation of the oxygen supply unit 63 so that oxygen is injected into the burner 50 by the loaded oxygen injection amount. .

According to the above-described method, a certain amount of dust can be uniformly injected into the melting furnace 10, and an amount of oxygen capable of generating a flame at an appropriate temperature can be automatically injected into the burner 50 according to the input amount of the dust. . Therefore, the dust injected into the melting furnace 10 may be aggregated to an appropriate particle size by the flame of the burner 50 and settled on the melting furnace bed 11, thereby improving the recycling efficiency and melting furnace efficiency of the dust.

In the above, preferred embodiments of the present invention have been described, but the present invention is not limited thereto, and it is possible to implement various modifications within the scope of the claims, the detailed description of the invention, and the accompanying drawings. It is natural to fall within the scope of

10: melting furnace 20: cyclone
30: dust bin 40: transfer pipe
50: burner 60: dust recycling device
61: weight measuring unit 62: dust feeder
63: oxygen supply unit 70: control unit
81: first flexible hose 82: second flexible hose

Claims (12)

A weight measuring unit installed in a dust bin that receives and stores dust from a cyclone, and measures the weight of dust accumulated in the dust bin;
A dust feeder installed in a conveying pipe connecting the outlet of the dust bin and the burner, and adjusting the amount of dust discharged in connection with the increase in dust per unit time of the dust bin;
An oxygen supply unit connected to the oxygen inlet of the burner and configured to adjust an oxygen injection amount of the burner in connection with the amount of dust discharged per unit time of the dust feeder; And
It is electrically connected to the weight measurement unit, the dust feeder, and the oxygen supply unit, and controls the operation of the dust feeder and the oxygen supply unit according to the measurement result of the weight measurement unit, and controls the operation of the dust feeder and the oxygen supply unit. A control unit including a memory storing information on a temperature condition capable of coagulating to an appropriate size and an oxygen injection amount for realizing this temperature condition
Dust recycling device of the melting furnace comprising a. The method of claim 1,
The dust discharge per unit time of the dust feeder is equal to the increase in dust per unit time of the dust bin,
The dust recycling apparatus of the melting furnace in which the oxygen injection amount of the oxygen supply part is proportional to the dust discharge amount per unit time of the dust feeder. The method of claim 2,
The weight measurement unit is composed of any one of a load cell and a strain gauge,
Dust recycling apparatus of a melting furnace in which flexible hoses are respectively installed at the inlet and outlet of the dust bin. The method of claim 2,
The dust feeder is a dust recycling device of a melting furnace composed of any one of a rotary feeder and a screw feeder. delete The method of claim 1,
When the weight of the dust measured by the weight measuring unit is greater than or equal to the reference weight, the control unit operates the dust feeder,
Dust recycling apparatus of a melting furnace, wherein the dust discharge amount per unit time of the dust feeder is equal to the increase amount of dust per unit time of the dust bin. delete The method of claim 1,
The control unit loads information on the oxygen injection amount from the memory according to the composition of dust and the discharge amount per unit time of the dust feeder, and controls the operation of the oxygen supply unit so that oxygen is injected into the burner by the loaded oxygen injection amount. Dust recycling device in the melting furnace. In the dust recycling method using the dust recycling device of claim 1,
Measuring the weight of the dust accumulated in the dust bin by the weight measuring unit;
Discharging dust from the dust feeder toward the burner; And
The oxygen supply unit includes the step of supplying oxygen to the oxygen inlet of the burner,
The control unit controls the operation of the dust feeder and the oxygen supply unit according to the measurement result of the weight measurement unit,
The dust discharge rate per unit time of the dust feeder is the same as the increase amount of dust per unit time of the dust bin, and the oxygen injection amount of the oxygen supply unit is proportional to the dust discharge amount per unit time of the dust feeder. The method of claim 9,
The control unit is a dust recycling method of the melting furnace operating the dust feeder when the weight of the dust measured by the weight measuring unit is more than a reference weight. delete The method of claim 9,
The control unit loads information on the oxygen injection amount from the memory according to the composition of dust and the discharge amount per unit time of the dust feeder, and controls the operation of the oxygen supply unit so that oxygen is injected into the burner by the loaded oxygen injection amount. How to recycle dust in the furnace.

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