JP3962140B2 - Hot stove operation method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for operating a hot stove, and more particularly, to a novel improvement for increasing the heat storage amount of the hot stove by increasing the combustion time by speeding up the exhaust pressure and the charging time when the hot stove is switched.
[0002]
[Prior art]
In general, the method shown in FIGS. 10 and 11 is adopted as a method for operating a hot blast furnace for sending hot air to a blast furnace, and the configuration of the hot blast furnace is configured as shown in FIG.
That is, what is indicated by reference numeral 1 in FIG. 8 is a blower, and this blower 1 is connected to the first hot stove 3 via the first blower valve 2a and the first air-blowing valve 2b, and the second blower valve 2c. The second hot air furnace 4 is connected to the second hot air furnace 4 and the third hot air furnace 2 is connected to the third hot air furnace 5 via the third air blowing valve 2e and the third air blowing valve 2f.
First to third gas shutoff valves 7a to 7c are connected to the first to third hot stove 3 to 5 from a gas main pipe 6 that guides fuel gas, and first to third flue valves 9a to 9a are connected. It is connected to the chimney 10 via 9c, and further connected to the blast furnace 12 via the blower main pipe 13 via the first to third hot air valves 11a to 11c. The first to third flue valves 9a to 9c are connected in parallel to the first to third exhaust valves 8a to 8c.
In this case, as an example, the first hot stove 3 is used as a combustion furnace to store heat, the second hot stove 4 that has been stored so far is used as a blower furnace, and the third hot stove 5 is used as a combustion furnace. In this case, for example, it is assumed that the amount of heat is reduced as the blast furnace of the second hot stove 4, the first hot stove 3 is sufficiently stored, and the second hot stove 4 is switched from the blast furnace as the combustion furnace. The switching operation is performed so that the 1 hot stove 3 is used as the blower from the combustion furnace, and the third hot stove 5 is continued as the combustion furnace. At the present time, the first hot stove 3 operates as a combustion furnace, so that the first hot stove 3 burns gas and stores heat while the first gas shut-off valve 7a and the first flue valve 9a are open. However, when the brick in the heat storage chamber in the furnace reaches a predetermined temperature, a signal indicating that the heat storage is over is output from the arithmetic processing unit 34, and a switching operation signal is output to start switching.
That is, as shown in FIG. 8, first, the first gas shut-off valve 7a is closed in order to shut off the combustion, and then the first flue valve 9a is closed.
As shown in FIG. 9, the basic operation pattern of the hot stove operation is a furnace change cycle in which the air blowing time is constant. When the No. 1 hot stove 3 finishes burning, a furnace change signal is issued, and at the same time, the No. 2 hot stove 4 is instructed to end the blowing, but only after the No. 1 hot stove 3 is changed. A furnace change signal for the No. 2 hot stove 4 is issued, and the operation starts from now on. Note that the furnace switching pattern of FIG. 9 is the same as that of the conventional and the present invention.
[0003]
When the first flue valve 9a is closed, the pressure in the furnace of the first hot stove 3 becomes equal to the atmospheric pressure, and Ls (limit switch) that monitors the opening / closing of the first charging valve 2b as preparation for blowing air shown in FIG. ) Is opened from the closed state, a signal for opening the first charge valve 2b is output from the arithmetic processing unit 34, and the first charge valve 2b is opened and Ls is opened. In addition, after the time T6 has elapsed in anticipation of safety, it is determined that the blowing pressure is equal to the pressure in the furnace, and a command signal for opening the first hot air valve 11a is issued. After a predetermined time has passed, the limit of the first hot air valve 11a is reached. When the switch Ls is turned on, it is confirmed that the first hot air valve 11a is fully opened, and further, the first blower valve 2a is opened, and cold air from the blower 1 passes through the first blower valve 2a to the bricks of the first hot stove 3 Heat exchange with stored heat 1st hot air valve 1 Hot air to the blast furnace 12 is supplied via a.
[0004]
On the other hand, as shown in FIGS. 10 and 11, the second hot air furnace 4 is connected to the second hot air valve 11b and the second air valve 2c from the time when a signal indicating that the first hot air furnace 3 has been switched from combustion to air blowing is issued. Close and get ready for heat storage.
That is, as shown in FIG. 10, a signal for opening the second exhaust valve 8b is issued to allow time required for the operation of the valve, and when the valve is opened all at once, the heat storage bricks stretched on the hot stove are separated. Therefore, the small valve opening is controlled so that the air blow is completed and the valve is closed by taking the timer times of the small timers T2 and T3.
Further, the second exhaust valve 8b is opened over a predetermined time of the timer time of the exhaust pressure holding timer T2 from the timer time of the exhaust air valve small timer T1. After the timer T2 has elapsed as the time required to open the valve from the timer T1, the exhaust valve open / close confirmation limit switch Ls outputs an open signal, and after the timer time of the timer T3 has elapsed, exhausting is complete. It is determined that the pressure has been reached, the second flue valve 9b and the second gas shut-off valve 7b are opened, and combustion gas is supplied to the second hot stove 4 to start combustion. The plurality of hot blast furnaces 3 to 5 thus supplied successively supply hot blast to the blast furnace 12 by sequentially repeating combustion and air blowing processes for storing heat. It should be noted that the extraction and processing of the signals of each control system described above are performed by the arithmetic processing unit 34.
[0005]
[Problems to be solved by the invention]
Since the conventional operation method of a hot stove was configured as described above, the following problems existed.
In other words, the pre-set time for both the air blow preparation (charging) and the combustion preparation (exhaust air) at the time of switching the hot air furnace is performed based on the timer operation.
Originally, the preparation for blowing is completed when the pressure in the furnace of the hot stove that is blowing ahead coincides with the pressure in the hot stove that tries to blow behind.
Furthermore, the completion of combustion preparation is when the furnace pressure of the hot stove that is blowing air is equal to the atmospheric pressure, but if the operation is performed with the timer set as described above, the operation is performed at the furnace pressure. Since management is not performed, a long time setting management is inevitably performed because it is necessary to perform safe operation with less trouble.
For this reason, it takes time to charge and exhaust the hot blast furnace at the time of switching, and the furnace replacement time becomes long. As a result, the combustion time for heat storage was shorter as the furnace change time was longer.
[0006]
The present invention has been made to solve the above-described problems. In particular, the time for changing the furnace at the time of changing the furnace of the hot blast furnace is changed to a pressure management method in the furnace to reduce the time for changing the furnace. An object of the present invention is to provide a method for operating a hot stove to increase the heat storage amount of the hot stove by extending the time.
[0007]
[Means for Solving the Problems]
The operation method of the hot stove according to the present invention is a first to first method for detecting the pressure in the furnace of each hot stove in the operation of the hot stove to control the hot air of the hot stove connected to a plurality of blast furnaces arranged. provided with a pressure sensor, using the switching signal for controlling the valve of each hot air furnace is al, and first to third pressure signal from the first one to three pressure sensors, a closing signal for controlling the valve of each hot air oven Is a method for performing a comparison operation and performing a comparison operation, and switching the hot blast furnace if the calculation result is equivalent to a preset setting condition, and also sending a hot air prior to the blast furnace. in hot air oven that is trailing the hot air oven to, and conditions GaNaru elevational represented by the following formula (1), when the trailing hot air furnace is in transition to the blower from the rest and, preceding a hot air oven and after Judging that the furnace pressure of the hot stove is equal, Open the hot air valve of the hot air furnace,
C-A ≦ 10 Kpa (1) Formula A: In-furnace pressure value of the following hot-air stove C: In-furnace pressure value of the preceding hot-air stove In a state where the blower valve and the hot-air valve of the preceding hot stove are closed This is a method in which the flue valve is opened when it is determined that the exhaust air has been exhausted when the in-furnace pressure of the preceding hot air furnace becomes 10 Kpa or less when the exhaust air valve is open.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a method for operating a hot stove according to the present invention will be described in detail with reference to the drawings.
In addition, the blower 1, each blower valve 2a, 2c, 2e, each charging valve 2b, 2d, 2f, each hot air furnace 3, 4, 5, each shut-off valve 7a, 7b, 7c, each exhaust valve 8a, 8b, 8c, each flue valve 9a, 9b, 9c, each hot air valve 11a, 11b, 11c, the gas main pipe 6, the chimney 10, the blast furnace 12, and the blower main pipe 13 are the same as the conventional structure shown in FIG. Since only the sensor is added to the part (indicated by a dotted line in FIG. 8), the configuration of FIG. 8 is applied to the embodiment of the present invention as it is, and the description thereof is omitted.
[0009]
That is, as the pressure sensors for detecting the pressures in the furnaces of the plurality of hot stoves, the first hot stove 3 has the first pressure sensor 30, the second hot stove 4 has the second pressure sensor 31, and the third hot stove 5 has A third pressure sensor 32 is provided, and a pressure value, which is a furnace pressure signal from each pressure sensor 30, 31, 32, is taken into the arithmetic processing unit 34. Further, a fourth pressure sensor 33 that detects the blowing pressure is also provided in the blowing main pipe 13 that sends hot air to the blast furnace, and the pressure signal of the fourth pressure sensor 33 is also taken into the arithmetic processing unit 34. Blow valves 2a, 2c, 2e, charge valves 2b, 2d, 2f, shut-off valves 7a, 7b, 7c, exhaust valves 8a, 8b, 8c, smoke provided in a plurality of hot air furnaces 3, 4, 5 An open / close signal of a well-known Ls (limit switch) (not shown) for monitoring the open / close state of the road valves 9a, 9b, 9c and the hot air valves 11a, 11b, 11c is also taken into the arithmetic processing unit 34.
[0010]
FIG. 1 shows a configuration in which the above-described signals according to the present invention are taken into the arithmetic processing unit 34, but an unillustrated opening / closing Ls (limit) provided for monitoring the opening / closing of the first to third hot air valves 11a to 11c. An open / close signal from the switch) is taken into the arithmetic processing unit 34, and further, the pressure values in the furnaces of the first to third hot stove furnaces 3 to 5 and the air pressure value for sending air to the blast furnace are taken in.
[0011]
FIG. 2 shows a situation where the arithmetic processing unit 34 performs an operation for performing a furnace replacement operation for stopping combustion and sending hot air to the blast furnace 12.
If the value obtained by subtracting the in-furnace pressure value of the subsequent hot stove from the in-furnace pressure value of the preceding hot stove is 10 Kpa or less, It is judged that the wind has been completed, and the opening / closing operation time of each hot stove valve is taken in, and a signal for opening the hot stove valve of the subsequent hot stove is issued.
At this time, the reason why the pressure threshold is set to 10 Kpa is that the blowing pressure to the blast furnace 12 is about 400 Kpa, and the control valve provided in the hot stove has a large differential pressure to open and close with the butterfly valve. This is because the load is large and cannot be mechanically opened and closed, and if it is about 3% or less of the blowing pressure, the operation is not hindered.
Note that the command to open the hot air valve of the subsequent hot stove after a predetermined time (by the timer) has elapsed after completion of the air charging is that the pressure ΔP at the time of air charging is 10 Kpa. In order to ensure safety, a timer is set to ensure time for pressure to drop.
[0012]
Next, FIG. 3 shows the control of the process of stopping the blowing and moving to combustion.
The blower valve of the preceding hot stove is closed, the hot air valve of the preceding hot stove is closed, the exhaust air valve is opened, and when the in-furnace pressure of the preceding hot stove is 10 Kpa or less, a signal for exhausting air is output. However, in anticipation of safety, a certain waiting time is set by a timer, and after the preset time has elapsed, the flue valve of the preceding hot stove furnace is opened to start combustion and perform heat storage.
[0013]
Next, the determination of the control signal shown in FIG. 2 will be described with reference to the flowchart of FIG. 6 (performed by the arithmetic processing unit 34).
When the preceding first hot stove 3 is currently switched to the second hot stove 4 at the end of the ventilation, the second hot stove 4 is switched from the first hot stove 3 to the second hot stove 4 at the end of the heat storage. If it is confirmed that the furnace switching notice signal has been turned on from OFF in the first step 100, a command signal for opening the second charging valve 2d of the second hot stove 4 is issued in the second step 101. . In the third step 102, it is confirmed whether or not the second charging valve 2d is opened. When the second charging valve 2d is fully opened, in the fourth step 103, the operation shown in FIG. 2 is preceded by the arithmetic processing unit 34 in the furnace pressure of the first hot air furnace 3 and the furnace of the hot air furnace 4 that follows. Calculate whether the difference in internal pressure is the same or less than 10 Kpa, and if the above condition is met, determine that charging is complete and open the second hot air valve 11b of the subsequent hot air furnace 4 to send hot air to the blast furnace 12 Become a wind furnace.
[0014]
Next, the furnace replacement process from the air suspension to the combustion heat storage shown in FIG. 3 is shown in FIG.
In the first step 200, it is confirmed whether the furnace switching notice signal has been turned off from on. If it is off, a command to open the exhaust valve is turned on in the second step 201, but when the exhaust valve is opened at once, Since there is a possibility that the brick constructed for the heat storage of the hot stove may be peeled off, the timer T1 that is opened after a certain period of time is started.
In the third step 202, it is confirmed whether or not the set timer time has elapsed since the timer T1 is started. When this timer time has elapsed, a stop signal for stopping the driving of the exhaust valve is output in the fourth step 203, and the exhaust time is also discharged. The timer T2 is started in order to secure time for holding the pressure. When the timer T2 confirms that the timer has elapsed in the fifth step 204, the sixth step 205 issues a command to open the exhaust valve and opens the exhaust valve. The exhaust valve is opened to calculate whether or not the pressure in the furnace has become 10 Kpa or less by the arithmetic processing unit 34 in the seventh step 206, and if it is 10 Kpa or less, it is determined that the exhaust has been completed in the eighth step 207. In order to ensure reliable operation, set the holding time for a few seconds and then open the preceding hot-blast furnace flue valve.
4 and 5 show the difference between the conventional operation method and the operation method according to the present invention, both of the time required for charging and exhausting can be shortened.
[0015]
【The invention's effect】
Since the operation method of the hot stove according to the present invention is configured as described above, the following effects can be obtained.
Using taken out a signal charge and wind completion and air exhaust complete the process pressure data values or we obtained furnace pressure force of the pressure sensor provided on each hot air oven, switch the furnace on the basis of the determination data obtained by the processing Therefore, it is possible to minimize the operation time by the time setting management by the conventional timer, shorten the time required for the furnace change, extend the heat storage combustion time, and greatly increase the heat storage amount. done. Further, if the heat storage amount is constant, the fuel consumption rate can be reduced by reducing the gas calorie of the fuel to be input by extending the time.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an explanatory view illustrating a method for operating a hot stove according to the present invention.
FIG. 2 is an explanatory diagram for explaining a charging signal processing of the present invention.
FIG. 3 is an explanatory diagram for explaining the exhaust signal processing of the present invention.
FIG. 4 is a characteristic diagram comparing the relationship between time and pressure related to the present invention and the conventional air charging.
FIG. 5 is a characteristic diagram comparing the relationship between time and pressure relating to the present invention and conventional exhaust air.
FIG. 6 is a flowchart for explaining air blowing (charging) from a pause according to the present invention.
FIG. 7 is a flowchart for explaining combustion (exhaust air) from a pause according to the present invention.
FIG. 8 is a configuration diagram illustrating the configuration of the present invention and a conventional hot stove.
FIG. 9 is an explanatory diagram showing an outline of the present invention and a conventional furnace switching state.
FIG. 10 is a characteristic diagram of an exhaust valve showing an operation with a conventional time setting.
FIG. 11 is a characteristic diagram of a rechargeable valve showing an operation with a conventional time setting.
[Explanation of symbols]
1 Blowers 2a, 2c, 2e Blower valves 2b, 2d, 2f Charging valve 3 First hot stove 4 Second hot stove 5 Third hot stove 6 Gas main pipes 7a, 7b, 7c Gas shut-off valves 8a, 8b, 8c Wind valve 9a, 9b, 9c Flue valve 10 Chimney 11a, 11b, 11c Hot air valve 12 Blast furnace 13 Blower main body 30, 31, 32 First to third pressure sensor 33 Fourth pressure sensor 34 Arithmetic processing unit

Claims (3)

In operation of a hot stove controlled to control hot air of a hot stove connected to a plurality of blast furnaces arranged, first to third pressure sensors (30 to 30) that detect the pressure in each hot stove (3 to 5) 32) provided with a, with a switching signal for controlling the valve of each hot-air furnace (3-5) to the al, the first to third pressure signal from the first one to three pressure sensors (30-32), each The open / close signal for controlling the valves of the hot stove (3-5) is taken into the arithmetic processing unit (34) and compared, and if the result is the same as the preset condition, the hot stove is switched. A method of operating a hot stove. In hot air oven that is trailing with hot air oven preceding is sending hot air prior to the blast furnace (12), a hot air oven to condition GaNaru elevational represented by the following formula (1), is trailing and has The hot air valve of the subsequent hot stove is opened when it is determined that the in-furnace pressure of the preceding hot stove and the subsequent hot stove are equal when the transition from the pause to the blow is in progress. How to operate the hot stove.
C−A ≦ 10 Kpa (1) Formula where A: pressure value in the furnace of the subsequent hot stove C: pressure value in the furnace of the preceding hot stove   When the blast valve (2a) and the hot blast valve (11a) of the preceding hot stove (3) are closed and the exhaust wind valve (8a) is open, the in-furnace pressure of the preceding hot stove becomes 10 Kpa or less. 3. A method for operating a hot stove according to claim 1 or 2, wherein the flue valve (9a) is opened when it is determined that exhaust air has been exhausted.

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