JP4839921B2 - Cooling method for hot stove - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a method for cooling a hot stove furnace, and more particularly, a method for cooling the inside of a hot stove furnace in order to perform repair work such as cracks in an iron skin or damage to bricks in the furnace due to deterioration over time. About.

When producing pig iron by melting and reducing iron ore in a blast furnace, hot air generated in the hot blast furnace is blown into the furnace from the tuyere provided in the blast furnace, and smelting reduction is performed.
As a hot stove, what is shown, for example in patent document 1 is known. 3 to 4 hot blast furnaces are installed for one blast furnace, a combustion furnace body having an internal space as a combustion chamber, a heat storage furnace body having an internal space as a heat storage chamber and a built-in heat storage body, and a combustion chamber And a connected furnace provided between the combustion furnace body and the heat storage furnace body so that the upper space of the heat storage chamber communicates, and the combustion gas generated in the combustion chamber is transferred to the heat storage chamber via the connection furnace. Supply for a certain period of time, store the thermal energy held by the combustion gas in the heat storage body located in the heat storage chamber, stop supplying the combustion gas to the heat storage chamber, and supply heating air to the stored heat storage chamber for a certain period of time Then, the heating air is heated by the heat energy stored in the heat storage body, and the process of generating hot air is repeated alternately to generate hot air from the cold air.
JP 2004-68136 A

By the way, the furnace walls of the combustion furnace body, the heat storage furnace body, and the connected furnace are composed of an iron skin and an in-furnace brick provided inside the iron skin. Due to deterioration, many cracks of the iron skin and damaged parts of the bricks in the furnace occur, so the hot blast furnace is stopped and the furnace wall is repaired.
When refurbishing the furnace wall, it is necessary to cool the inside of the hot stove furnace to a temperature at which workers can enter the inside (the brick temperature inside the furnace in the upper part of the heat storage chamber is about 40 ° C.). The method of cooling the inside of the hot stove furnace is to forcibly supply cooling air from the lower part to the upper part of the heat storage chamber and flow the cooling air that has reached the upper part of the heat storage chamber to the combustion chamber through the connected furnace. After that, a method of releasing to the atmosphere from an exhaust bleeder provided with a combustion furnace body is performed.

However, in this cooling method, the pressure loss until the cooling air passing from the heat storage chamber to the combustion chamber reaches the exhaust bleeder increases, and only a small amount of cooling air can be discharged from the exhaust bleeder to the atmosphere, and circulates in the furnace. Since there is a limit to the amount of cooling air, a long cooling period of about 1 to 2 months is required until the cooling in the furnace of the hot stove is completed.
The present invention has been made to eliminate such inconveniences, and provides a cooling method for a hot stove that can cool the inside of the furnace in a short period of time and can greatly improve the cooling efficiency. Objective.

  In order to solve the above-mentioned problems, a cooling method for a hot stove according to the present invention comprises a heat storage furnace body filled with a heat storage body with the internal space as a heat storage chamber, a combustion chamber as the internal space, and a burner at the bottom of the combustion chamber And a connected furnace communicating between the regenerator body and the upper part of the combustion furnace body and communicating between the heat storage chamber and the combustion chamber is cooled. In this method, the upper outer wall of the regenerative furnace body is removed to provide an exhaust hole for communication between the heat storage chamber and the atmosphere, and the lower side where the burner of the combustion furnace body is disposed is communicated with the atmosphere. , Forcibly supplying the atmosphere from the lower part of the heat storage furnace body into the heat storage chamber, and generating a flow of the heat storage chamber cooling air flowing from the lower part to the upper part of the heat storage chamber and discharged to the outside air from the exhaust hole And the draft effect due to the flow of cooling air in the heat storage chamber. The combustion chamber cooling air that flows into the lower part of the combustion chamber flows upward, passes through the connected furnace, flows to the upper part of the heat storage chamber, and is discharged from the exhaust hole to the outside air. This is a method for cooling a hot stove so as to generate a flow.

  According to the cooling method for a hot stove of the present invention, a heat storage chamber having a large heat retention amount is generated by generating a flow of the heat storage chamber cooling air that flows from the lower part to the upper part of the heat storage room and is discharged from the exhaust hole to the outside air. It can be cooled in a short period of time. In addition, due to the draft effect of the heat storage chamber cooling air flow, the atmosphere that has entered the lower part of the combustion chamber flows upward, and the flow of the combustion chamber cooling air that passes through the connected furnace and is released from the exhaust holes to the outside air is reduced. By generating it, the combustion chamber can also be cooled in a short period of time. Therefore, the present invention can greatly improve the efficiency in cooling the hot stove.

Hereinafter, an embodiment of a hot stove according to the present invention will be described with reference to the drawings.
First, one of the hot stoves installed in three to four blast furnaces will be described with reference to FIG.
The hot stove of this embodiment includes a regenerative furnace body 2, a combustion furnace body 4, and a communication furnace 6 that communicates the interior of the regenerative furnace body 2 and the combustion furnace body 4. The inside of the heat storage furnace body 2 is a heat storage chamber 2a, and the inside of the combustion furnace body 4 is a combustion chamber 4a. Domes 8 and 10 are formed on the upper part of the heat storage furnace body 2 and the combustion furnace body 4, and the dome parts 8 and 10 are connected via the communication furnace 6 so that the heat storage chamber 2a and the combustion chamber 4a are connected. The upper part of is in communication.

And the furnace wall of the thermal storage furnace body 2, the combustion furnace body 4, and the communication furnace 6 is comprised with the iron brick and the in-furnace brick provided inside the iron shell.
The heat storage chamber 2 a of the heat storage furnace body 2 is filled with the heat storage body 8, and a heating air intake 12 and a discharge opening 14 are provided at the lower part of the heat storage furnace body 2. 12 is connected to a pipe 18 through which cooling air is supplied via a valve 16, and the discharge port 14 is connected to a pipe 24 connected to an exhaust chimney 22 via a valve 20.

  A fuel gas supply port 26 and a combustion air supply port 28 are provided in the lower portion of the combustion furnace body 4. A fuel gas supply pipe 32 is connected to the fuel gas supply port 26 via a valve 30, and a combustion air pipe 36 for supplying combustion air via a valve 34 is connected to the combustion air supply port 28. ing. The fuel gas supply pipe 32 is connected via a damper 33 to a heat absorption pipe 35 that passes through the inside of the regenerative furnace body 2 and supplies fuel gas. A burner 38 for burning the fuel gas supplied from the fuel gas supply pipe 32 with the combustion air supplied from the combustion air pipe 36 is disposed below the combustion chamber 4a. Further, a hot air outlet 40 is provided in the vertical center of the combustion furnace body 4, and a hot air pipe 44 is connected to the hot air outlet 40 via a valve 42. Although not shown, the hot air pipe 44 is connected to tuyere provided in the blast furnace together with other hot air furnaces.

The hot stove configured as described above has the heat storage process in which the valves 16, 42 are closed and the valves 20, 26, 28 are opened, the valves 20, 26, 28 are closed, and the valves 16, 42 are opened. The hot air generation process is repeated alternately.
That is, in the heat storage process, the high-temperature combustion gas generated in the burner 38 at the lower part of the combustion chamber 4a passes through the communication furnace 6 from the upper part of the combustion chamber 4a and is supplied to the heat storage chamber 2a. By flowing from the upper part to the lower part, the heat storage 8 stores the thermal energy held by the combustion gas. The combustion gas that has released the thermal energy passes through the discharge port 14 and is discharged from the exhaust chimney 22 into the atmosphere.
In the hot air generating step, heating air is sent from the heating air intake 12 to the heat storage chamber 2a, and the heating air is heated by the heat energy held by the heat storage body 8 to generate hot air. Hot air generated in the heat storage chamber 2a flows from the upper part of the heat storage chamber 4a to the combustion chamber 4a through the communication furnace 6, passes through the hot air outlet 40, and is supplied to the blast furnace side.

Next, a characteristic method of the present embodiment for cooling the hot stove to perform the renovation work will be described with reference to FIG.
In the present embodiment, the valve 42 is closed, the valves 26 and 28 are opened, and the lower part of the combustion chamber 4 a is communicated with the atmosphere via the combustion air pipe 36 and the heat absorption pipe 35. Further, the valves 16 and 20 are closed.
Further, a blower fan 52 is connected to a furnace body opening 50 provided in the lower part of the heat storage furnace body 2 via a supply pipe 52. Furthermore, the outer wall of the dome portion 8 of the heat storage furnace body 2 is removed using a dismantling means such as a heavy machine, and an exhaust hole 48 is provided through which the upper portion of the heat storage chamber 2a communicates with the atmosphere.
And the ventilation fan 52 is driven, air | gas is forcedly supplied to the lower part of the thermal storage furnace body 2, and cooling of a hot stove is started.

  According to the present embodiment, when the atmosphere is forcibly supplied from the lower part of the heat storage furnace body 2, the heat energy held in the heat storage body 8 is air by the flow of air (atmosphere) from the lower part to the upper part of the heat storage chamber 2a. The heated air is released from the exhaust hole 48 to the outside. As described above, the heat storage chamber 2a having a large heat retention amount is cooled in a short period of time by the air discharged from the exhaust hole 48 to the outside while moving from the lower portion to the upper portion as indicated by an arrow A1. In addition, the flow of arrow A1 is corresponded to the flow of the thermal storage chamber cooling air of this invention.

  Further, due to the draft effect of the flow of air (flow of arrow A1) discharged from the lower part to the upper part in the heat storage chamber 2a and to the outside from the exhaust hole 48, the combustion chamber 4a is connected to the furnace from the lower part to the upper part. 6, the natural flow of air (atmosphere) discharged from the exhaust hole 48 to the upper part of the heat storage chamber 2a is generated (flow of arrow A2), so that the combustion chamber 2a is also in a short period of time. To be cooled. Note that the flow of the arrow A2 corresponds to the flow of the combustion chamber cooling air of the present invention.

  Thus, the cooling method of the hot stove of the present embodiment generates a flow of air (atmosphere) from the lower part of the heat storage chamber 2a toward the upper part by forcibly supplying the atmosphere from the lower part of the heat storage furnace body 2, The amount of heat in the heat storage chamber 2a filled with the heat storage body 8 is discharged from the exhaust hole 48 to the outside in a short period of time, and due to the draft effect of the flow of air (atmosphere) from the lower portion to the upper portion of the heat storage chamber 2a, the combustion chamber 4a From the lower part of the gas, the natural flow of air (atmosphere) that passes through the connected furnace 6 and goes to the upper part of the heat storage chamber 2a is also generated, and the amount of heat in the combustion chamber 4 is discharged from the exhaust hole 48 to the outside in a short period of time. Therefore, the cooling efficiency can be greatly improved.

FIG. 2 shows a temperature change in the upper part of the heat storage chamber 2a (position indicated by T1) and a temperature change in the lower part of the heat storage chamber 2b (position indicated by T2) when the method for cooling the hot stove of the present embodiment is performed. This data is shown. Note that the completion of cooling of the hot stove is at least when the in-furnace brick temperature above the heat storage chamber a becomes constant at 40 ° C.
Conventional cooling method for hot stove (cooling air is forcibly supplied from the lower part to the upper part of the heat storage chamber, and the cooling air that has reached the upper part of the heat storage chamber flows into the combustion chamber through the connected furnace, and then burns. In the method of discharging to the atmosphere from the exhaust bleeder provided in the furnace body, a long cooling period of about 1 to 2 months is required until the cooling of the hot air furnace in the furnace is completed.
However, in the hot stove cooling method of this embodiment, the brick temperature in the furnace at the top of the heat storage chamber a can be lowered to about 40 ° C. in 15 days at the longest. It can be seen that the efficiency is greatly improved.

It is a figure which shows the structure of a hot stove, and the flow of the air at the time of cooling. It is a graph which shows the temperature change in the thermal storage chamber at the time of performing the cooling method of the hot stove of this invention.

Explanation of symbols

2 Heat storage furnace body 2a Heat storage chamber 4 Combustion furnace body 4a Combustion chamber 6 Linked furnace 8, 10 Dome part 26 Fuel gas supply port 28 Air supply port for inflammation 38 Burner 48 Exhaust hole 50 Furnace body opening 52 Cold air fan

Claims (1)

A heat storage furnace body in which an internal space is used as a heat storage chamber and filled with a heat storage body, a combustion furnace body in which the internal space is a combustion chamber, and a burner is disposed below the combustion chamber, and the heat storage furnace body and the combustion furnace body A method of cooling a hot stove provided with a connected furnace communicating between the heat storage chamber and the combustion chamber by communicating between the upper parts of
Removing the upper outer wall of the regenerative furnace body to provide an exhaust hole for communication between the heat storage chamber and the atmosphere, communicating the lower side where the burner of the combustion furnace body is disposed with the atmosphere,
While forcibly supplying air from the lower part of the heat storage furnace body into the heat storage chamber, and generating a flow of heat storage chamber cooling air that flows from the lower part of the heat storage chamber toward the upper part and is released from the exhaust hole to the outside air ,
Due to the draft effect caused by the flow of the heat storage chamber cooling air, the air that has entered the lower portion of the combustion chamber flows upward, and further passes through the connection furnace and flows to the upper portion of the heat storage chamber to form the exhaust hole. A method for cooling a hot stove characterized in that a flow of combustion chamber cooling air released from the atmosphere to the outside air is generated.

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