JP3409968B2 - Furnace temperature control method for continuous heating furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a furnace temperature control for a continuous heating furnace.
More specifically, the furnace in the longitudinal direction of the continuous heating furnace
Continuous heating furnace capable of arbitrarily controlling internal temperature distribution
And a method for controlling the furnace temperature. [0002] 2. Description of the Related Art A continuous heating furnace has a plurality of longitudinal directions inside the furnace.
Zone, and the predetermined furnace temperature for each zone
To be heated, and the objects to be heated are continuously carried in from the entry side of each zone.
The heating object is transported at a constant speed in the furnace.
A device that heats to a temperature. As a heating source of this continuous heating furnace, a regenerative heating furnace is used.
It is known that a burner device is provided in a furnace. Thermal storage
The burner device is a burner in which the heat storage body and the burner are integrated.
Composed of two units as a pair, the combustion air for the burner
Air supply and exhaust of combustion gas from the burner
And burn the two burners alternately to raise the temperature inside the furnace
Device By the way, the conventional continuous heating furnace is a furnace in the downstream zone.
The internal temperature is the furnace temperature in the upstream zone or the upstream zone.
Furnace temperature affects downstream furnace temperature.
Therefore, the furnace temperature in each zone is controlled and maintained at a desired temperature.
It was difficult to hold. Also, the heating condition of the object to be heated
Items, for example, objects to be heated with different sizes and quantities (amounts to be delivered)
Heated objects with different heating temperatures during loading and extraction
When combining into a continuous heating furnace,
There were many restrictions. [0004] That is, a heated object (a large amount of
After the heated object, the object to be heated (a small amount of heated material)
), The quantity of combustion increases due to the large amount of heated objects.
In addition, the zone where the regenerative burner was burning
Heat is stored, and a small amount of
Even if the combustion of the regenerative burner device is stopped, a small amount of
It takes time to lower the temperature inside the furnace suitable for heating
Heating the low-temperature object to be heated at a predetermined temperature in a short time
And prevented improvement of work efficiency. [0005] The object to be heated which needs to be heated at a high temperature
(Hot object to be heated)
Even when a hot object (low-temperature object to be heated) is carried in,
A regenerative burner system with increased combustion for warm objects
In the zone where gas was burning, heat was stored in the furnace,
Combustion of a regenerative burner device in a zone for a heated object
Even if the temperature is stopped, a predetermined furnace temperature suitable for heating the low-temperature heated object
It takes time for the temperature to drop to
Since the heated object cannot be heated at the predetermined temperature,
In this way, the work efficiency was hindered. Therefore, the above problem can be solved.
As technology, for example, Japanese Patent Application Laid-Open No.
Hereinafter, this is referred to as Conventional Technology 1. ), JP-A-7-97719
What is described in the gazette (hereinafter, referred to as prior art 2)
is there. In the prior art 1, the furnace is divided into a plurality of zones.
In each of these zones, fuel is burned to the burner through the heat storage.
Supply combustion air and discharge combustion gas from burners
One or more regenerative alternating combustion burner systems
It has a heating furnace provided above, and the temperature in the furnace length direction of this heating furnace is
By temperature detection means provided at least one in each zone
And responds based on the detection result of the temperature detection means.
The combustion of the regenerative alternating combustion burner system in the zone
Method when the furnace temperature is lower than the set temperature.
The fuel supplied to the regenerative alternating combustion burner system
If the furnace temperature is higher than the set temperature,
The fuel supplied to the combustion burner system has been reduced. According to the prior art 1, a plurality of zones
At least one regenerative alternating combustion burner system
The temperature in the furnace length direction of the heating furnace equipped with
The furnace temperature is detected by the provided temperature detecting means,
Based on the detection result, the furnace temperature of each zone is independently set
By adjusting the temperature pattern inside the furnace,
It can be set arbitrarily. [0009] Further, the prior art 2 discloses that the combustion air is
The supply of air and the exhaust of combustion gas alternately pass through the regenerator.
Furnace with regenerative alternating combustion burner system
Off the supply of combustion gas to one or more unit furnaces or zones.
Passed the heat storage unit of another unit furnace or zone through a valve
A heating furnace equipped with a combustion gas supply system for supplying fuel gas
You. [0010] According to the prior art 2, a high-temperature heated product is drawn.
When heating the low-temperature heating object continuously, supply the combustion gas.
Supply of low-temperature combustion gas into unit furnace or zone by system
The temperature in the unit furnace or zone in a short time
Reduce to a temperature suitable for heating, or lower the furnace temperature
Adjust the temperature pattern to suit the heating of the heating object.
As a result, work efficiency is greatly improved. [0011] However, the prior art
In operation 1, the temperature distribution in the furnace length direction of the heating furnace was increased to the set temperature.
A regenerative alternator installed in each zone to approximate the accuracy
Control to increase or decrease the fuel supply to the combustion burner system
So many fuel measuring devices and fuel flow control valves
Is necessary, and the piping system is complicated.
There is a possibility that the cost may increase. [0012] Further, the prior art 2 is based on a predetermined unit furnace or zonal furnace.
Through a combustion gas supply switching valve to another unit furnace or zone.
Gas supply to supply fuel gas that has passed through the heat storage
The heating furnace is brought close to the set temperature by installing a system.
As a result, it becomes a complicated piping system and equipment costs increase.
There is it. Accordingly, the present invention has been made to solve the above-mentioned prior art problems.
Inexpensive system
To improve control responsiveness and to provide highly accurate temperature in the furnace length direction.
Furnace temperature control method of continuous heating furnace that can provide distribution
It is intended to provide. [0014] Means for Solving the Problems To achieve the above object,
For example, the furnace temperature control method for a continuous heating furnace according to claim 1 is as follows.
The temperature in the furnace is raised to a predetermined temperature in the furnace, and from the inlet side in the furnace.
The object to be heated that has been continuously carried in is directed toward the furnace length in the furnace.
A heater that heats while moving at a predetermined speed to the exit side
In a continuous heating furnace, a pair of burners and
A regenerative burner device having a regenerator to be connected to the furnace.
Multiple sets are installed at predetermined intervals in the furnace length direction within
For the pair of burners of the regenerative burner device, the heat storage
Combustion by supplying combustion air that has passed through
Burner and heat storage by passing exhaust gas in the furnace through the heat storage body
Switching to non-combustion burner to operate alternately every predetermined time
Combustion control, and the pair of burners alternately
Real combustion per unit time to switch and perform combustion operation
The time is set for each pair of burners in each set, and
Switching combustion of each pair of burners based on the actual combustion time
By performing baking control, the inside of the furnace is heated in the furnace length direction.
With a temperature distribution,Each pair of burners
Change from combustion operation to heat storage operation and from heat storage operation to combustion operation.
Combustion and heat storage during one cycle
An operation pause time to pause all operations is provided.
By setting the time between long and short times,
A method of setting the effective combustion time for each pair of burners.
You. Here, the actual burning time per unit time and
In this case, a pair of burners alternately switch between combustion operation and heat storage operation.
In other words, when performing switching combustion,
Time when one burner performs a combustion operation and the other burner
It is the total time with the time for performing the operation. The furnace temperature control of the continuous heating furnace according to claim 1.
According to the control method, when keeping the furnace temperature constant,
The pair of burners of all sets of regenerative burners
A state in which the actual combustion time per interval is set to the same time
To switch combustion. This allows the furnace to be positioned in the furnace length direction.
All regenerative burners installed at regular intervals
Since the heating amount is the same, the furnace
Length from the inlet side of the furnace to the outlet side of the furnace where the object to be heated is carried out
The temperature distribution in the direction becomes uniform. Further, the furnace temperature on the inlet side of the furnace is set high.
When setting the furnace temperature at the outlet side of the furnace low,
Of the regenerative burner installed on the entrance side
Set the burner to a long burn time and set the burner on the outlet side of the furnace.
The pair of burners of the regenerative burner installed is actually
Switching combustion is performed by setting the combustion time to a short time. this
Increases the heating capacity of the regenerative burner device on the inlet side in the furnace
And the heating amount of the regenerative burner device on the outlet side in the furnace decreases.
Therefore, the temperature in the furnace length direction from the entrance side in the furnace to the exit side in the furnace
The distribution has a downward slope. Furthermore, the furnace temperature on the inlet side of the furnace is set low.
If the furnace temperature at the outlet side of the furnace is set high,
Of the regenerative burner installed on the entrance side
The burner is set to a short effective burn time, and
The pair of burners of the regenerative burner installed is actually
Switching combustion is performed by setting the combustion time to a long time. this
Reduces the amount of heat in the regenerative burner unit on the inlet side in the furnace
And the heating amount of the regenerative burner on the outlet side in the furnace increases.
Therefore, the temperature in the furnace length direction from the entrance side in the furnace to the exit side in the furnace
The distribution is in a state of having an upward slope. As described above, a predetermined interval is set in the furnace length direction in the furnace.
The unit time per unit of multiple regenerative burner units
Control response by simply changing the actual combustion time
Temperature distribution along the furnace length with high accuracy
You. Also,A pair of burners from each set
One that alternately switches from the heat storage operation and the heat storage operation to the combustion operation
During one cycle, stop all combustion and heat storage operations
Operation pause time, and this operation pause time is extended for a long time or
Is a short time, so that each pair of burners
Set the substantial burning time, i.e. long or short
Only a short period of operation downtime, each pair of bars
Since the actual combustion time is set for each fuel,
No special adjustment valve or piping system is required for
Thus, an inexpensive furnace temperature control system can be provided. [0021] [0022] BRIEF DESCRIPTION OF THE DRAWINGS FIG.
It will be described based on the following. Fig. 1 shows the application of the present invention to a continuous heating furnace
It is a schematic structure figure showing the embodiment in the case of doing. In the figure, reference numeral 1 denotes a slab (conveyed object) which is continuously conveyed.
Is a continuous heating furnace that heats the slab
Carry in from the side, pre-tropical zone 2, first heating zone 3, second heating zone 4
And heated sequentially after passing through the tropics 5
The lab is unloaded from the right side and transported to the next process.
ing. In the first heating zone 3, as shown in FIG.
Two regenerative burner devices 6A to 6D are provided. This
Waste gas discharged from these regenerative burner devices 6A to 6D
Is sucked by the waste gas suction fan 8 and shown in FIG.
The chimney 9 releases the air to the atmosphere. Each of regenerative burner devices 6A to 6D
Is a pair arranged in the first heating zone 3 as shown in FIG.
Burner 10A₁, 10A_Two-10D₁, 10D_TwoWith
I do. The burner 10 of the regenerative burner device 6A
A₁, 10A_TwoFrom the fuel gas supply ports 11a and 11b
Combustion gas is supplied and combustion air is supplied
Primary air nozzle (not shown) and generated in the first heating zone 3
A secondary air nozzle (not shown) that sucks waste gas
The primary air nozzle and secondary air nozzle
The air nozzle communicates with the combustion air supply / discharge ports 18a, 18b.
I have. At the tip of the nozzle of the burners 10a and 10b,
Pilot burners 12a and 12b are provided. So
And burner 10A₁, 10A_TwoFuel gas supply port 11
a and 11b are further connected via fuel cutoff valves 13a and 13b.
Through the main shutoff valve 14 and the fuel control valve 15
Connected to a combustion gas supply source 16 that supplies M gas as
ing. The fuel control valve 15 is connected to the burner 10A.
₁, 10A_TwoCan supply a predetermined flow rate of M gas to
Thus, the flow rate can be adjusted. The pilot bar
The fuel tanks 12a and 12b are also fueled through the shutoff valves 17a and 17b.
Connected to a gas supply source 16. Furthermore, the burner 10A₁, 10A_TwoBurning of
The air supply / discharge ports 18a, 18b are connected to branch pipes 19a, 19b.
And store heat in the middle of these branch pipes 19a and 19b.
The bodies 20a, 20b are provided. These branch pipes 1
9a and 19b are connected via air shutoff valves 21a and 21b.
And air for pumping combustion air through the combustion air control valve 22.
Connected to the air blower 23 and the air shutoff valve 21
Waste gas shut-off valves 24a, 24b connected in parallel with a, 21b
Through the waste gas flow control valve 25 and through the waste gas flow control valve 25.
It is also connected to the draw fan 8. Further, each of the heat storage bodies 20a and 20b
Has a diameter of 20 mm as a heat storage medium along the gas flow passage.
mm of alumina balls
High temperature waste gas discharged from the first heating zone 3 to the ball
Heat is exchanged and stored, and this heat storage is
It is replaced and heat is dissipated. Further, the fuel cutoff valves 13a and 13b,
Shut-off valve 14, fuel control valve 15, air shut-off valve 21a, 2
1b, combustion air control valve 22, waste gas cutoff valve 24a, 24
b and the waste gas flow control valve 25 control the entire continuous heating furnace 1.
Direct connected to the process computer 28
Digital controller (hereinafter referred to as DDC) 29
Is controlled by Further, the other regenerative burner devices 6B to 6D
Burner 10B₁, 10B_Two-10D ₁, 10D_TwoBefore
Burner 10A of regenerative burner device 6A described above₁, 10A
_TwoThe same piping system and valves are provided. The DDC 29 is used to determine the fuel flow rate, combustion air
Adjust the fuel so that the air flow rate and the waste gas flow rate are the specified values.
Valve 15, combustion air control valve 22, and waste gas flow control valve 25
Output a flow rate adjustment signal to the
Switching time of a pair of burners of the burner devices 6A to 6D is determined.
Accordingly, the fuel cutoff valves 13a, 13
b, air shutoff valves 21a, 21b and waste gas shutoff valve 24
a, 24b is controlled to open and close to perform the combustion operation
Of burners are switched to heat storage operation and are performing heat storage operation
The other burner is switched to the combustion operation. That is, a pair of the regenerative burner device 6A
Burner 10A₁, 10A_TwoBriefly explain the operation of
Then, one burner 10A₁Performs the combustion operation and the other
Burner 10A_TwoIs performing a heat storage operation,
Burner 10A₁From outside air to the air blower 23
Therefore, the combustion air in the cool air state fed by pressure is
Supply to the heat storage unit 20a via the valve 22 and the air cutoff valve 21a
The alumina board stored in the heat storage body 20a
The heat is exchanged with the heat and preheated to a predetermined temperature. And preheat
Burned air is burner 10A₁Combustion air supply / discharge port 18
a, and mixed with the fuel gas injected from the combustion nozzle.
The furnace is heated by joint combustion. At the same time, the other bar
10A_TwoThen, the secondary air nozzle is connected to the combustion air supply / discharge port 18.
b, heat storage body 20b, waste gas cutoff valve 24b, waste gas flow rate control
It communicates with the waste gas suction fan 8 via the drain valve 25,
Waste gas is sucked by the waste gas suction fan 8 to store heat
The heat storage body 20b is discharged through the body 20b.
The heat exchange between the alumina balls and waste gas in
The heat storage temperature of the heat storage body 20b is set so as to be suitable for preheating the air.
Gradually increase. FIG. 3 is a plan view of the inside of the first heating zone 3.
This is shown visually, and the scanning path is indicated by reference numeral 31 in the drawing.
The love S passes at a predetermined speed. And inside the first heating zone 3
The regenerative burner devices 6A to 6D of the section
The downstream side 3 in the traveling direction
1a is provided with a regenerative burner device 6A, and the upstream side 31b
Is provided with a regenerative burner device 6D.
Other regenerative burner devices 6B, 6 between the burner devices 6A, 6D.
C are arranged at predetermined intervals. In addition, heat storage type
Burner 10A of the burner device 6A₁Of the transport path 31
Disposed on one side and the other burner 10A_TwoIs the transport path 3
1 burner 10A disposed on the other side₁Facing
ing. And other regenerative burner devices 6B-6D also
One burner 10B is provided on one side of the conveyance path 31.₁-10D₁
And the other burner 10B on the other side._Two-10D_TwoTo
They are arranged and face each other. In this embodiment, the slab S is heated.
Furnace temperature in the first heating zone 3 required for
(Temperature).
I do. Here, the DDC 29 is loaded into the first heating zone 3.
For the size and capacity of the slab S to be heated and for heating the slab S
The required target temperature and the location of the slab S passing through the transport path 31
Slab information such as furnace time is stored in the process computer 28.
Has been entered from time to time. Also, a furnace is provided in the first heating zone 3.
A temperature sensor 30a is provided.
The temperature of the furnace in the first heating zone 3 is also input to the DDC 29 from time a.
Have been. The DDC 29 is the current
4 based on the furnace temperature and slab information in heating zone 3
Of the regenerative burner devices 6A to 6D as shown in FIG.
By performing the switching control, the first heating zone 3 in the furnace length direction is controlled.
Temperature distribution can be set in various patterns That is, FIG. 4 shows that the furnace length direction of the first heating zone 3 is a constant height.
Regenerative bar that sets the required furnace temperature to be in a hot state
FIG. 4 is a time chart showing combustion switching of the burner devices 6A to 6D.
But at time T₁, All regenerative burners
One of the burners 10A of the units 6A to 6D₁-10D₁Fuel
The shutoff valve 13a and the air shutoff valve 21a are opened, and the waste gas is shut off.
The valve 24a is closed and the other burner 10A is closed._Two-10
D_TwoClosed the fuel cutoff valve 13b and air cutoff valve 21b
State, the waste gas cutoff valve 24b is opened, and one burner
10A₁-10D₁In the combustion state, the other burner 10A_Two
-10D_TwoIs in a heat storage state. Next, at time T_TwoIn one burner
10A₁-10D₁Fuel cutoff valve 13a and air cutoff valve
21a is closed, and the other burner 10A_Two-10D_Two
Closed the waste gas shut-off valve 24b of all the burners.
The combustion state and the heat storage state are stopped. Then, a short pause time RT₁Has passed
Time T_ThreeIn all the regenerative burner devices 6A to 6
One burner 10A of D₁-10D₁Waste gas shut-off valve 2
4a is opened and the other burner 10A_Two-10D_Twoof
Open the fuel cutoff valve 13b and the air cutoff valve 21b.
And one burner 10A₁-10D₁The heat storage state, the other
Burner 10A_Two-10D_TwoIs set to a combustion state. Next, a predetermined combustion time CT₁Has passed
Later, time T_Four, One burner 10A₁-10D
₁Of the other burner 1 is closed.
0A _Two-10D_TwoFuel cutoff valve 13b and air cutoff valve 2
With 1b closed, the combustion state and heat storage of all burners
Stop the state. Then, a short break similar to the above-mentioned time is performed.
Stop time RT₁At the time T_FiveIn one of the ba
10A₁-10D₁In the combustion state, the other burner 10
A_Two-10D_TwoIs switched to the heat storage state. And the predetermined
Combustion time CT₁After a lapse of time T₆At all
The combustion state and heat storage state of the burner are stopped. The same applies hereinafter
At time T_ThreeThe same cycle is repeated thereafter. The above-described combustion switching time chart of FIG.
Then, all the regenerative burner devices 6A to 6D have the same pause.
Time (operation pause time) RT₁And combustion time
Interval) CT₁To switch combustion, and one cycle
Le YT₁Pause time RT during₁Is set short and all heat storage
Time CT of the burners 6A to 6D₁Set longer
Therefore, as shown by the solid line in FIG.
Transport path position L₁, Transport path position L on the upstream side 31b_FourAnd more
Has their position L₁, L_TwoL between_Two, L_ThreeTransport path
Even at the position, the furnace temperature is substantially the same. this
The temperature distribution in the furnace length direction must be uniform and high temperature
The furnace temperature can be set. FIG. 5 shows the downstream side 31 of the first heating zone 3.
a must be in a high temperature state and the upstream side must be in a low temperature state.
The fuel of the regenerative burner devices 6A to 6D for setting the furnace required temperature
FIG. 3 is a time chart showing a changeover time of a sintering operation._TenTo
Then, one burner 10A ₁-10D₁The combustion state and
And the other burner 10A_Two-10D_TwoIn the heat storage state
You. Next, at time T₁₁In, all burners
10A₁-10D₁To stop combustion and heat storage
You. And a short pause RT_TwoTime T
₁₂, One bar of the regenerative burner devices 6A, 6B
10A₁, 10B₁In the heat storage state, the other burner 10A
_Two, 10B_TwoIs set to a combustion state. Then, at the time of predetermined combustion
CT between_TwoAfter a lapse of time T₁₃In the burner 10
A₁, 10A_Two, 10B₁, 10B_TwoCombustion state and storage
Stop the thermal condition. And just like the time mentioned earlier,
Pause time RT between_TwoAt the time T₁₄In, one
Burner 10A₁, 10B₁The combustion state, the other 10
A_Two, 10B_TwoIs switched to the heat storage state. And the predetermined
Combustion time CT_TwoAfter a lapse of time T_FifteenAt all
The combustion state and heat storage state of the burner are stopped. The same applies hereinafter
And a short pause RT_TwoTime T₁₆smell
At time T₁₂The same cycle is repeated thereafter. On the other hand, the regenerative burner devices 6C and 6D
Point T₁₁Relatively long pause time RT _ThreeTime T
₁₇At one burner 10C₁, 10D₁The heat storage
State, the other burner 10C_Two, 10D_TwoTo the combustion state
You. Next, the combustion time C of the regenerative burner devices 6A and 6B
T_TwoShorter predetermined combustion time CT_ThreeAfter the time elapses,
T₁₈In the burner 10C₁, 10C_Two, 10D₁,
10D_TwoThe combustion state and the heat storage state are stopped. And
Relatively long pause time RT similar to the time described above_ThreeProvided
After time T₁₉At one burner 10C₁, 10
C₁The combustion state, the other 10C_Two, 10C_TwoThe heat storage state
Switch to. Then, a predetermined combustion time CT _ThreeHas passed
Later, time T₂₀State and heat storage of all burners
Stop the state. Hereinafter, similarly, the relatively long pause time R
T_ThreeTime T_{twenty one}At time T₁₇As above
Is repeated. The above-described combustion switching time chart of FIG.
Then, the regenerative storage bar disposed on the downstream side 31a of the first heating zone 3
Storage devices 6A and 6B and a heat storage type disposed on the upstream side 31b
The burner devices 6C and 6D are different from each other in terms of downtime and combustion time.
Combustion switching cycle, and regenerative burner devices 6A, 6B
1 cycle of YT_TwoPause time during operation (operation pause time) RT
_TwoIs set short, and the combustion time (effective combustion time) CT_TwoThe length
And the regenerative burner devices 6C, 6D
1 cycle of YT_ThreePause time during operation (operation pause time) RT
_ThreeIs set longer and the combustion time (effective combustion time) CT_ThreeShort
As shown by the dashed line in FIG.
Transport path position L on the upstream side 31a₁The furnace temperature is high and
Conveyance path position L on the side 31b_FourFurnace temperature decreases
Going down. As a result, the temperature distribution in the furnace
Required furnace temperature with a downward slope in the direction of travel of bus S
Can be set. FIG. 6 shows the downstream side 31 of the first heating zone 3.
a must be in a low temperature state and the upstream side must be in a high temperature state.
The fuel of the regenerative burner devices 6A to 6D for setting the furnace required temperature
FIG. 3 is a time chart showing a changeover time of a sintering operation.₂₀To
In one of the regenerative burner devices 6A to 6D,
10A₁-10D₁Into the combustion state and the other burner
10A_Two-10D_TwoIs in a heat storage state. Next, at time T_{twenty one}In, all burners
10A₁-10D₁To stop combustion and heat storage
You. And a relatively long pause time RT_FourHas passed
T_{twenty two}In one of the heat storage burner devices 6A and 6B,
10A₁, 10B₁In the heat storage state, and the other burner 10
A_Two, 10B_TwoIs set to a combustion state. Then, the prescribed combustion
Time CT_FourAfter a lapse of time T_{twenty three}In, burner 1
0A₁, 10A_Two, 10B₁, 10B_TwoCombustion state and
Stop the heat storage state. And, like the time mentioned above,
Relatively long pause time RT_FourAt the time T_{twenty four}smell
And one burner 10A₁, 10B₁The combustion state, the other
10A_Two, 10B_TwoIs switched to the heat storage state. And
Predetermined combustion time CT_FourAfter a lapse of time T_{twenty five}At
The combustion state and the heat storage state of all the burners are stopped. Less than
Below, similarly, short pause time RT_FourTime T
₂₆At time T_{twenty two}Repeat the same cycle
Do. On the other hand, the regenerative burner devices 6C and 6D
Point T_{twenty one}Short pause RT from_FiveTime T₂₇
At one burner 10C₁, 10D₁The heat storage
State, the other burner 10C_Two, 10D_TwoTo the combustion state
You. Next, the combustion time C of the regenerative burner devices 6A and 6B
T_FourLonger predetermined combustion time CT_FiveAfter the time elapses,
T ₂₈In the burner 10C₁, 10C_Two, 10D₁,
10D_TwoThe combustion state and the heat storage state are stopped. And
Short pause time RT similar to the above-mentioned time_FiveEstablished
Later, time T₂₉At one burner 10C₁, 10C
₁The combustion state, the other 10C_Two, 10C_TwoTo heat storage
Switch. Then, a predetermined combustion time CT_FiveHas passed
Later, time T₃₀State and heat storage of all burners
Stop the state. Hereinafter, similarly, the short pause time RT
_FiveTime T₃₁At time T ₂₇Similar to the following
Repeat the cycle. The above-described combustion switching time chart of FIG.
Then, the regenerative storage bar disposed on the downstream side 31a of the first heating zone 3
Storage devices 6A and 6B and a heat storage type disposed on the upstream side 31b
The burner devices 6C and 6D are different from each other in terms of downtime and combustion time.
Combustion switching cycle, and regenerative burner devices 6A, 6B
1 cycle of YT_FourPause time during operation (operation pause time) RT
_FourIs set longer and the combustion time (effective combustion time) CT_FourShort
And the regenerative burner devices 6C, 6D
1 cycle of YT_FivePause time during operation (operation pause time) RT
_FiveIs set short, and the combustion time (effective combustion time) CT_FiveThe length
As shown by the two-dot chain line in FIG.
Transport path position L on the upstream side 31a₁The furnace temperature is low
Conveyance path position L on the side 31b_FourFurnace temperature rises toward
It is getting better. As a result, the temperature distribution in the furnace
The required furnace temperature, which was inclined upward in the traveling direction of the lab S
The degree can be set. Therefore, in the present embodiment, the transport path 31
Four regenerative burners installed at predetermined intervals along
6A to 6D, the pair of burners 10A₁, 10
A_Two-10D₁, 10D_TwoReal combustion per unit time
Just by changing the time, the loading amount of slab S, transport speed,
The longitudinal direction of the transport path 31 according to the heating amount of the slab S, etc.
Controlling the temperature distribution in the (furnace length direction) with high accuracy by improving the response
Can be attached. In this embodiment, a long time or
Short pause time RT₁~ RT_Five, Just provide
A pair of burners 10 of four regenerative burner devices 6A to 6D
A₁, 10A_Two-10D₁, 10D_TwoReal combustion time C
T₁~ CT_FiveSupply and stop of fuel
This eliminates the need for special adjustment valves and piping systems for
A cost-effective furnace temperature control system can be provided. In the above embodiment, the first heating
When four regenerative burner devices 6A to 6D are installed in zone 3
In the above description, the above-described DD is also applied to the second heating zone 4.
Installed multiple regenerative burners controlled by C29
However, the same operation and effect can be obtained. Also heat storage
The number of burners is limited to the above
Rather, the same effect can be obtained with a larger number of units.
Obtainable. The fuel supplied to the burners 10a and 10b is
The case where M gas is used as a charge has been described.
It is not limited to this, and other fuel gas, heavy oil, etc.
Liquid fuel can be applied. Further, the combustion switching control of this embodiment is performed by DDC.
Although the case where it was made to perform in 29 was explained,
Not limited to other programmable controllers or sequence systems
The sequence may be controlled by a control circuit or the like.
No. Further, the fuel for the burners 10a and 10b
Separate air shutoff valve 21 for supply of burning air and discharge of waste gas
a, 21b and waste gas shut-off valves 24a, 24b
However, the present invention is not limited to this.
A switching mechanism using a directional switching valve that switches the flow path
It may be configured. Further, in each of the above embodiments,
The case where the present invention is applied to a continuous heating furnace has been described.
However, the present invention is not limited to this.
It can be applied to a furnace or the like. [0056] As described above, according to the first aspect,
The furnace temperature control method for continuous heating furnaces maintains the furnace temperature constant.
In this case, a pair of regenerative burner units
To the same actual combustion time per unit time.
Switch combustion is performed in the set state. This allows the furnace
All heat storages installed at predetermined intervals in the furnace length direction
Since the heating amount of the burner unit is the same,
Out of the furnace where the object to be heated is carried out from the entrance side of the furnace
The temperature distribution in the furnace length direction up to the side can be made uniform.
You. Further, the furnace temperature on the inlet side of the furnace is set high.
When setting the furnace temperature at the outlet side of the furnace low,
Of the regenerative burner installed on the entrance side
Set the burner to a long burn time and set the burner on the outlet side of the furnace.
The pair of burners of the regenerative burner installed is actually
Switching combustion is performed by setting the combustion time to a short time. this
Increases the heating capacity of the regenerative burner device on the inlet side in the furnace
And the heating amount of the regenerative burner device on the outlet side in the furnace decreases.
Therefore, the temperature in the furnace length direction from the entrance side in the furnace to the exit side in the furnace
The distribution can be set to have a downward slope. Further, the furnace temperature on the inlet side of the furnace is set low.
If the furnace temperature at the outlet side of the furnace is set high,
Of the regenerative burner installed on the entrance side
The burner is set to a short effective burn time, and
The pair of burners of the regenerative burner installed is actually
Switching combustion is performed by setting the combustion time to a long time. this
Reduces the amount of heat in the regenerative burner unit on the inlet side in the furnace
And the heating amount of the regenerative burner on the outlet side in the furnace increases.
Therefore, the temperature in the furnace length direction from the entrance side in the furnace to the exit side in the furnace
The distribution can be set to a state with an upward slope. As described above, according to the present invention, in the furnace length direction in the furnace,
Multiple sets of regenerative burners installed at predetermined intervals
The real combustion per unit time of those pair of burners
Because it is a method that only changes the time, the amount of material to be heated
Depending on the transfer speed, heating amount of the object to be heated, etc.
Temperature distribution can be attached with high accuracy by improving control response.
Wear. [0060]Furthermore,Long or short time
Just by setting a pause, the actual operation of each pair of burners
Quality combustion time, so supply and stop fuel
Eliminates the need for special regulating valves and piping systems to perform
A simple furnace temperature control system can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram showing a continuous heating furnace according to the present invention. FIG. 2 is a schematic configuration diagram showing a plurality of regenerative burner devices according to the present invention. FIG. 3 is a plan view showing a pair of burners and a heat storage body of a plurality of sets of regenerative burners installed in a heating path. FIG. 4 is a time chart of a first example showing switching combustion timing of a plurality of sets of regenerative burners according to the present invention. FIG. 5 is a time chart of a second example showing switching combustion timings of a plurality of sets of regenerative burners according to the present invention. FIG. 6 is a time chart of a third example showing switching combustion timings of a plurality of sets of regenerative burners according to the present invention. FIG. 7 is a table showing the temperature distribution in the furnace length direction in the furnace set by the switching combustion timing shown in the first to third time charts. [EXPLANATION OF SYMBOLS] 1 continuous heating passage 3 first heating zone (furnace) 6A-6D regenerative burner device _{10A 1, 10A 2 ~10D 1,} 10D 2 burners 20a, 20b regenerator CT ₁ to CT ₅ burn time (real burn time) RT ₁ to RT ₅ rest time (operation pause time) S slab (object to be heated) YT ₁ ~YT ₅ switching the combustion cycle

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Jun Shimizu 1-chome, Mizushima-Kawasaki-dori, Kurashiki-shi, Okayama Pref. Chome (without address) Inside the Mizushima Works of Kawasaki Steel Corporation (56) References JP-A-6-193386 (JP, A) JP-A-8-226634 (JP, A) JP-A-6-241439 (JP, A (58) Field surveyed (Int.Cl. ⁷ , DB name) F23N 5/20 F23L 15/02

Claims (1)

(57) [Claims] [Claim 1] The inside of the furnace is heated to a predetermined furnace temperature, and the object to be heated continuously carried in from the inlet side of the furnace is moved in the furnace length direction. In a continuous heating furnace that heats while moving to a delivery side at a predetermined speed toward a discharge side, a regenerative burner device having a pair of burners and a heat storage body connected to these burners is provided in the furnace. A plurality of sets are installed at predetermined intervals in the furnace length direction, and a combustion burner that performs a combustion operation by supplying combustion air that has passed through the regenerator to a pair of burners of each regenerative burner device; Per unit time when the combustion control is performed by alternately switching the exhaust gas in the chamber to the non-burning burner performing the heat storage operation by passing the heat storage body at predetermined time intervals, and performing the combustion operation by switching the pair of burners alternately. For each pair of burners in each set. Each set, by performing the switching combustion control of each set of the pair of burners on the basis of the real burning time, while raising the temperature with a temperature distribution inside the furnace to the furnace length direction, each set of pair Burner changes from combustion operation to heat storage operation and heat storage operation
During one cycle of alternately switching from cropping to combustion operation,
Set an operation pause time to suspend all combustion operation and heat storage operation.
In this case, the operation pause time is set to a long time or a short time.
By the above, the actual combustion time for each pair of burners of each set
A method for controlling a furnace temperature of a continuous heating furnace, comprising setting the temperature.