JP5398685B2 - Combustion control method of regenerative burner in heating furnace - Google Patents

Description

  The present invention supplies a burner unit provided with a fuel gas supply pipe, a heat storage chamber containing a heat storage material, and combustion air to the heat storage chamber on both sides in the transfer direction of the material to be processed that is transferred inside the heating furnace. The present invention relates to a combustion control method for a regenerative burner in a heating furnace provided with a pair of a regenerative burner having an air supply pipe and an exhaust gas discharge pipe for discharging combustion exhaust gas from a heat storage chamber. In particular, in the above heating furnace, when heat-treating a material to be treated such as a long slab, so as to have a sufficient thermal gradient from one end side to the other end side of the material to be treated such as a long slab, It is characterized in that the material to be treated can be appropriately heated.

  Conventionally, when heat-treating a material to be treated, from a burner portion provided with a fuel gas supply pipe, a heat storage chamber containing a heat storage material, an air supply pipe for supplying combustion air to the heat storage chamber, and a heat storage chamber A regenerative burner having an exhaust gas discharge pipe for discharging combustion exhaust gas is used as a pair and a heating furnace provided on both sides in the conveying direction of the material to be treated is used. In one regenerative burner, from the air supply pipe through the heat storage chamber The combustion air is guided to the burner section, and the fuel gas is injected from the fuel gas supply pipe in the burner section to perform the combustion operation. In the other heat storage type burner, the combustion exhaust gas is guided to the heat storage chamber and burned. A heat storage operation is performed in which the heat of the exhaust gas is stored in the heat storage material and discharged from the exhaust gas discharge pipe, and in the paired heat storage burner, the combustion operation and the heat storage operation can be switched alternately. Are we.

  In the heating furnace as described above, when the combustion operation and the heat storage operation in the paired heat storage type burner are alternately switched in the same manner, the material to be treated is uniformly heated in the heating furnace. Become so.

  Here, when the material to be treated such as a long slab is uniformly heat-treated using the heating furnace as described above, and the material to be heated is guided to a hot rolling apparatus and hot rolled, Because it takes time to hot-roll a material to be processed such as a long slab, a large temperature difference between the leading end of the material to be initially guided to the hot rolling device and the rear end to be finally guided. As a result, the temperature at the time of rolling becomes non-uniform so that a uniform material cannot be obtained, and rolling at the rear end becomes difficult when the temperature is low.

  For this reason, conventionally, as shown in Patent Document 1, in the heating furnace as described above, the combustion operation time in each regenerative burner provided in a pair is made different so that the heat storage time is long. In the type burner, while increasing the suction ratio of the combustion exhaust gas during the heat storage operation, in the heat storage type burner with a short combustion operation time, the combustion air ratio is increased during the combustion operation so as to increase the amount of heat extracted from the heat storage material. In addition, a heating method is proposed in which a thermal gradient is provided so that the temperature of the rear end portion is increased in advance.

  However, in recent years, for the purpose of increasing production efficiency, the thickness of a material to be processed such as a long slab may be increased, and the time required to hot-roll the material to be processed becomes even longer. Even in the case shown in Document 1, it is difficult to heat the material to be processed so as to have a sufficient thermal gradient from one end side to the other end side of the material to be processed such as a long slab. In addition, for the purpose of increasing the heating efficiency, even when the thickness of the material to be processed is reduced, the material to be processed easily dissipates heat, which causes the same problem.

Japanese Patent No. 3356595

  The present invention supplies a burner unit provided with a fuel gas supply pipe, a heat storage chamber containing a heat storage material, and combustion air to the heat storage chamber on both sides in the transfer direction of the material to be processed that is transferred inside the heating furnace. In a heating furnace provided with a pair of a heat storage burner having an air supply pipe and an exhaust gas exhaust pipe for discharging combustion exhaust gas from the heat storage chamber, the above-mentioned in the case of heat-treating a material to be treated such as a long slab The problem is to solve such problems.

  In other words, in the present invention, a long slab or the like to be processed using a heating furnace provided with a pair of regenerative burners on both sides in the transfer direction of the material to be processed to be transferred in the heating furnace as described above. When heat-treating a material, the material to be treated can be appropriately heated by having a sufficient thermal gradient from one end side to the other end side of the material to be treated, such as a long slab. Therefore, it is an object of the present invention to appropriately hot-roll a material to be treated even when the thickness of the material to be treated is increased or decreased.

In the combustion control method of the regenerative burner in the heating furnace according to the present invention, in order to solve the above-described problems, fuel gas supply pipes are provided on both sides in the conveying direction of the material to be processed to be conveyed in the heating furnace. A heat storage type burner having a burner section, a heat storage chamber containing a heat storage material, an air supply pipe for supplying combustion air to the heat storage chamber, and an exhaust gas discharge pipe for discharging combustion exhaust gas from the heat storage chamber is provided as a pair. In one heat storage type burner, the combustion air is guided from the air supply pipe through the heat storage chamber to the burner part, and the fuel gas is injected from the fuel gas supply pipe in the burner part to perform the combustion operation, while the other heat storage type In the burner, the combustion exhaust gas is guided to the heat storage chamber, the heat of the combustion exhaust gas is stored in the heat storage material, and is discharged from the exhaust gas discharge pipe. The combustion control method for regenerative burners in the heating furnace in which the combustion operation of the heat storage operation is switched alternately, heating the treated material so that the temperature rises toward the opposite side from one side of said workpiece In this case, during the heat storage operation of the one-side regenerative burner, the amount of the combustion exhaust gas discharged from the exhaust gas exhaust pipe through the heat storage chamber is reduced compared to the normal heat storage operation or the exhaust of the combustion exhaust gas is stopped . During the combustion operation of the regenerative burner, the amount of fuel gas supplied from the fuel gas supply pipe to the burner section is reduced or stopped from being supplied during the normal combustion operation, while the one-side regenerative burner during combustion operation, the regenerative burner opposite, the amount of the combustion exhaust gas guided to the exhaust gas discharge pipe through the regenerator than normal thermal storage operation and to reduce

When the amount of the combustion exhaust gas discharged from the exhaust gas exhaust pipe through the heat storage chamber is reduced or the exhaust of the combustion exhaust gas is stopped during the heat storage operation of the heat storage burner on one side in this way, The heat storage material housed in the heat storage chamber of the heat storage burner is not sufficiently heated by the combustion exhaust gas, and the combustion air supplied to the heat storage chamber is not sufficiently heated during the combustion operation of this one side heat storage burner, Combustion air is guided to the burner part in a low temperature state and used for combustion, and the temperature during combustion is lowered. For this reason, the heating temperature in the part of the to-be-processed material close to the heat storage type burner on one side is lower than the heating temperature in the part of the to-be-processed material close to the heat storage type burner on the opposite side.

Also, if the amount of fuel gas supplied from the fuel gas supply pipe to the burner section is reduced compared to that during normal combustion operation or the supply of fuel gas is stopped during the combustion operation of the above-mentioned one-side regenerative burner, The temperature at the time of combustion of the regenerative burner further decreases, and the heating temperature in the portion of the material to be treated close to the regenerative burner on one side is further higher than the heating temperature in the portion of the material to be treated close to the regenerative burner on the other side. descend.

In addition, when performing the combustion operation of the regenerative burner on one side as described above, the amount of the combustion exhaust gas guided to the exhaust gas exhaust pipe through the heat storage chamber in the opposite regenerative burner is less than that in the normal heat storage operation. The temperature of the heat storage material housed in the heat storage chamber of the opposite heat storage burner is suppressed from being led to the heat storage chamber of the heat storage burner on the opposite side. Is suppressed from decreasing.

In addition, during the heat storage operation of the regenerative burner on one side as described above, the amount of combustion exhaust gas discharged from the exhaust gas exhaust pipe through the heat storage chamber is reduced compared to the normal heat storage operation , or the exhaust of combustion exhaust gas is stopped. If the amount of combustion exhaust gas led to the exhaust gas exhaust pipe through the heat storage chamber is reduced in the opposite side of the regenerative burner during the combustion operation of one side of the regenerative burner, Since the amount of combustion exhaust gas discharged through the pipe decreases and the pressure in the heating furnace fluctuates, it is preferable to discharge excess combustion exhaust gas through a flue provided in the heating furnace.

  In addition, when providing a pair of regenerative burners on both sides in the conveying direction of the workpiece to be conveyed in the heating furnace, a plurality of paired regenerative burners are provided, and the entire regenerative burner on one side and the opposite side As described above, it is also possible to control only a part of the regenerative burners on one side and the opposite side as described above.

In the present invention, in the regenerative burner provided in pairs on both sides in the conveyance direction of the material to be treated to be conveyed in the heating furnace as described above, the combustion operation and the heat accumulation operation are alternately switched to be treated. per to heat the workpiece so that the temperature rises toward the one side of the timber on the opposite side, when the heat storage operation of the one side of the regenerative burners, the usual heat storage amount of the combustion exhaust gas to be discharged from the exhaust gas discharge pipe through regenerator Since it has been reduced from the time of operation or emission of combustion exhaust gas is stopped, the heat storage material housed in the heat storage chamber of this one-side heat storage burner is not sufficiently heated by the combustion exhaust gas, and this one-side heat storage The combustion air supplied to the heat storage chamber is not sufficiently heated during the combustion operation of the burner, and the combustion air is led to the burner section at a low temperature and used for combustion. Kicking temperature is lowered.

  As a result, the heating temperature in the portion of the material to be treated close to the heat storage burner on one side is lower than the heating temperature in the portion of the material to be treated close to the heat storage burner on the opposite side, and the material to be treated such as a long slab It becomes possible to heat the material to be treated by having a larger thermal gradient from the one end side to the other end side, and the thickness of the material to be treated such as a long slab becomes larger or smaller. In such a case, the material to be treated can be appropriately hot-rolled.

It is the schematic sectional drawing which showed the internal state of the heating furnace used for the combustion control method of the regenerative burner in the heating furnace which concerns on one Embodiment of this invention. It is a schematic plan view of said heating furnace in the same embodiment. In the embodiment, it is the schematic explanatory drawing which showed the state which performs a combustion operation | movement with one heat storage type burner in the paired heat storage type burner, and performs a heat storage operation with the other heat storage type burner. In the same embodiment, it is the schematic explanatory view which showed the state which decreased the quantity of the combustion exhaust gas discharged | emitted from an exhaust gas exhaust pipe through a thermal storage chamber, or stopped the discharge of combustion exhaust gas at the time of the thermal storage operation | movement of the one-side heat storage type burner. In the same embodiment, it is the schematic explanatory drawing which showed the state which decreased the quantity of the fuel gas supplied to a burner part from a fuel gas supply pipe | tube, or stopped supply of a fuel gas at the time of combustion operation | movement of the one-side regenerative burner.

  Hereinafter, a combustion control method for a regenerative burner in a heating furnace according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings. In addition, the combustion control method of the regenerative burner in the heating furnace according to the present invention is not particularly limited to the one shown in the following embodiment, and can be implemented with appropriate modifications within a range not changing the gist of the invention. .

  Here, in this embodiment, as shown in FIGS. 1 and 2, the workpiece 1 such as a long slab guided from the inlet 11 of the heating furnace 10 into the heating furnace 10 is heated by the walking beam 2. The material to be treated 1 is conveyed and heated in the furnace 10, and the material 1 thus heated is taken out of the heating furnace 10 through the outlet 12 of the heating furnace 10.

  And in said heating furnace 10, the regenerative burner 20 which became the pair which has the burner part 21 and the thermal storage chamber 22 has opposed to the part of the both sides of the conveyance direction of the to-be-processed material 1 conveyed in the heating furnace 10. In this manner, a plurality of regenerative burners 20 that are paired are provided in the conveying direction of the material 1 to be processed with a necessary interval.

  Here, in the regenerative burner 20 in the above pair, as shown in FIG. 3, when performing a combustion operation in one regenerative burner 20a, combustion air is stored in the regenerator 22a in which the regenerator material 23a is accommodated. Open the air supply valve 25a provided in the air supply pipe 24a, and close the gas discharge valve 27a provided in the exhaust gas discharge pipe 26a for discharging the combustion exhaust gas through the heat storage chamber 22a. The combustion air led into the heat storage chamber 22a through 24a is heated by the heat storage material 23a accommodated in the heat storage chamber 22a.

  Then, the combustion air heated in this way is supplied to the burner part 21a, and a gas supply valve 29a for introducing the fuel gas to the fuel gas supply pipe 28a provided at the center of the burner part 21a is opened, and the fuel gas Is injected from the fuel gas supply pipe 28 a so that the fuel gas is burned in the heating furnace 10.

  On the other hand, when performing the heat storage operation in the other heat storage burner 20b, the gas supply valve 29b for supplying the fuel gas to the fuel gas supply pipe 28b and the air supply valve 25b provided in the air supply pipe 24b are closed to perform combustion. On the other hand, the gas discharge valve 27b provided in the exhaust gas discharge pipe 26b for discharging the combustion exhaust gas through the heat storage chamber 22b is opened.

  Then, the combustion exhaust gas after being burned in the heating furnace 10 as described above is guided to the heat storage chamber 22b, the heat storage material 23b accommodated in the heat storage chamber 22b is used to store the heat of the combustion exhaust gas, and then the combustion exhaust gas. Is discharged to the outside through the exhaust gas discharge pipe 26b.

  Then, in the heat storage burners 20a and 20b that are paired with each other, the combustion operation and the heat storage operation as described above are alternately switched.

  Here, if the combustion operation and the heat storage operation as described above are performed in the same manner in the pair of heat storage burners 20a and 20b, the workpiece 1 conveyed in the heating furnace 10 is disposed on both sides. The regenerative burners 20a and 20b are heated substantially uniformly.

  Next, in this embodiment, the workpiece 1 is heated so as to have a sufficient thermal gradient from one end side to the other end side of the workpiece 1 such as a long slab guided into the heating furnace 10. In doing so, the case where the heating temperature of the material to be treated 1 on the one heat storage burner 20a side is increased while the heating temperature of the material 1 on the other heat storage burner 20b side is lowered will be described.

  Here, when a combustion operation is performed in the regenerative burner 20a on the side where the heating temperature of the workpiece 1 is increased, a heat storage operation is performed in the regenerative burner 20b on the side where the heating temperature of the workpiece 1 is decreased, In the regenerative burner 20a on the side where the heating temperature of the treatment material 1 is increased, the normal combustion operation is performed as described above.

  On the other hand, during the heat storage operation of the regenerative burner 20b on the side of lowering the temperature at which the material to be treated 1 is heated, the gas discharge valve 27b is controlled to be opened and closed and discharged from the exhaust gas discharge pipe 26b through the heat storage chamber 22b. The amount of combustion exhaust gas to be reduced is reduced, or as shown in FIG. 4, the gas exhaust valve 27b is closed to stop the exhaust of combustion exhaust gas.

  If it does in this way, the heat storage material 23b accommodated in the heat storage chamber 22b in this heat storage type burner 20b will not fully be heated by combustion exhaust gas. If the amount of combustion exhaust gas discharged from the exhaust gas exhaust pipe 26b is reduced or the exhaust of combustion exhaust gas is stopped in this way, the amount of combustion exhaust gas in the heating furnace 10 increases and the pressure increases. In this embodiment, surplus combustion exhaust gas in the heating furnace 10 is discharged through the flue 13 provided in the heating furnace 10.

  Further, the operation of the heat storage burners 20a and 20b is switched to perform the combustion operation in the heat storage burner 20b on the side where the heating temperature of the material to be treated 1 is lowered, while the heating temperature of the material 1 to be raised is increased. When the heat storage operation is performed in the heat storage burner 20a, the heat storage burner 20b on the side where the heating temperature of the material to be processed 1 is lowered, as described above, the combustion air passes through the heat storage chamber 22b from the air supply pipe 24b. The gas supply valve 29b that guides the fuel gas to the fuel gas supply pipe 28b is controlled to be opened and closed to reduce the amount of fuel gas supplied from the fuel gas supply pipe 28b to the burner part 21b. As shown in FIG. 5, the gas supply valve 29b is closed so that the fuel gas is not supplied to the burner portion 21b.

  If it does in this way, since the thermal storage material 23b accommodated in the thermal storage chamber 22b in this thermal storage type burner 20b is not heated by combustion exhaust gas at the time of thermal storage operation as mentioned above, it supplies to the burner part 21b through this thermal storage chamber 22b. The temperature of the combustion air is lower than the temperature of the combustion air supplied to the burner portion 21a through the heat storage chamber 22a of the other heat storage burner 20a, and the fuel supplied to the burner portion 21b as described above. Since the amount of gas is reduced or fuel gas is not supplied to the burner portion 21b, the temperature in the vicinity of the regenerative burner 20b does not increase even during the combustion operation.

  On the other hand, during the heat storage operation of the regenerative burner 20a on the side where the heating temperature of the workpiece 1 is increased, the combustion exhaust gas in the heating furnace 10 is guided to the heat storage chamber 22a of the heat storage burner 20a, and the heat storage chamber 22a The heat storage material 23a accommodated in is stored in the heat storage material 23a to heat the combustion exhaust gas, thereby heating the heat storage material 23a. In the regenerative burner 20a, when the combustion operation is performed next, the combustion air heated by the heat storage material 23a thus heated is supplied to the burner portion 21a to burn the fuel gas.

If it does in this way, sufficient combustion will be performed in this heat storage type burner 20a, and the temperature near this heat storage type burner 20a will become higher than the temperature near the other heat storage type burner 20b. Further , during the heat storage operation of the heat storage burner 20a, the low-temperature combustion exhaust gas in the vicinity of the heat storage burner 20b on the opposite side is guided to the heat storage chamber 22a of the heat storage burner 20a and the heat of the heat storage material 23a is increased. In order to suppress the deprivation, the opening and closing of the gas discharge valve 27a is controlled to slightly reduce the amount of combustion exhaust gas guided to the heat storage chamber 22a . In this case, surplus combustion exhaust gas in the heating furnace 10 is discharged through the flue 13 provided in the heating furnace 10.

  Then, in the regenerative burner 20a on the side where the heating temperature of the material to be treated 1 is increased and the regenerative burner 20b on the side where the heating temperature of the material 1 is lowered, the combustion operation and the heat accumulation operation are performed as described above. If it repeats, the temperature near the regenerative burner 20a on the side where the heating temperature of the material to be treated 1 is increased will rise more than the temperature near the regenerative burner 20b on the side where the heating temperature of the material 1 will be lowered. The heating temperature of the portion of the workpiece 1 close to the heat storage burner 20a is increased, while the heating temperature of the portion of the workpiece 1 close to the heat storage burner 20b is lowered, so that a long slab or the like is heated. The treatment material 1 can be heated so as to have a sufficient thermal gradient from one end side to the other end side.

  Then, the workpiece 1 heated in such a manner as to have a sufficient thermal gradient from one end side to the other end side is led to a hot rolling device (not shown) from the side where the heating temperature is low, and heated. Even if it is the to-be-processed material 1 which takes time to hot-roll like a long slab when it is hot-rolled, it is between the front-end | tip part and rear-end part of the to-be-processed material 1 guide | induced to a hot rolling apparatus. Thus, the occurrence of a temperature difference during rolling is suppressed, and the workpiece 1 can be appropriately hot-rolled.

DESCRIPTION OF SYMBOLS 1 Material to be processed 2 Walking beam 10 Heating furnace 11 Inlet 12 Outlet 13 Flue 20, 20a, 20b Thermal storage type burner 21, 21a, 21b Burner part 22, 22a, 22b Thermal storage chamber 23a, 23b Thermal storage material 24a, 24b Air supply pipe 25a, 25b Air supply valve 26a, 26b Exhaust gas exhaust pipe 27a, 27b Gas exhaust valve 28a, 28b Fuel gas supply pipe 29a, 29b Gas supply valve

Claims (3)

A burner portion provided with fuel gas supply pipes on both sides in the conveying direction of the material to be processed to be conveyed in the heating furnace, a heat storage chamber containing the heat storage material, and an air supply pipe for supplying combustion air to the heat storage chamber The heat storage type burner having an exhaust gas discharge pipe for discharging combustion exhaust gas from the heat storage chamber is provided as a pair, and in one heat storage type burner, the combustion air is led from the air supply pipe through the heat storage chamber to the burner section. The fuel gas is injected from the fuel gas supply pipe in the section to perform the combustion operation, while in the other heat storage burner, the combustion exhaust gas is guided to the heat storage chamber, and the heat of the combustion exhaust gas is stored in the heat storage material, and the exhaust gas discharge pipe performs a heat storage operation for discharging from our combustion control method for regenerative burners in the heating furnace is switched alternately between combustion operation and the regenerative operation described above in regenerative burner paired Te, when to heat the workpiece so that the temperature toward the opposite side from one side of said material to be treated is increased, when the heat storage operation of the one side of the regenerative burner, the combustion exhaust gas is discharged from the exhaust gas discharge pipe through Regenerator amounts together than normal thermal storage operation to stop the discharge of the reduced or flue gas, upon combustion operation of the one side of the regenerative burner, usually the amount of fuel gas supplied from the fuel gas supply pipe to the burner unit The amount of combustion exhaust gas led to the exhaust gas exhaust pipe through the heat storage chamber in the heat storage type burner on the opposite side during the combustion operation of the one side heat storage type burner while reducing the fuel gas supply or stopping the supply of fuel gas The combustion control method for a regenerative burner in a heating furnace is characterized by reducing the amount of heat compared to the normal heat storage operation .   The regenerative burner in a heating furnace according to claim 1, wherein surplus combustion exhaust gas in the heating furnace is discharged through a flue provided in the heating furnace. Combustion control method. In the combustion control method of the regenerative burner in the heating furnace according to claim 1 or 2 , a plurality of paired regenerative burners are provided on both sides in the conveying direction of the material to be processed conveyed in the heating furnace. A combustion control method for a regenerative burner in a heating furnace.

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