JP5398686B2 - heating furnace - Google Patents

Description

  The present invention includes a burner section having 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 exhausting combustion exhaust gas in the heating furnace through the heat storage chamber. A regenerative burner having an exhaust gas discharge pipe is provided in pairs, and in the regenerative burner paired, the combustion air is guided from the air supply pipe through the heat storage chamber to the burner section, and the fuel gas in the burner section A combustion operation in which fuel gas is injected from the supply pipe and burned, and a heat storage operation in which the combustion exhaust gas in the heating furnace is guided to the heat storage chamber and the heat of the combustion exhaust gas is stored in the heat storage material and discharged from the exhaust gas discharge pipe. The present invention relates to a heating furnace that performs alternately. In particular, the present invention is characterized in that the heat of the combustion exhaust gas generated in the heating furnace is used more effectively.

  Conventionally, in order to perform efficient combustion using the heat of combustion exhaust gas, a burner portion provided with a fuel gas supply pipe, a heat storage chamber containing a heat storage material, and supply of combustion air to the heat storage chamber A heat storage burner having an air supply pipe and an exhaust gas discharge pipe for discharging the combustion exhaust gas in the heating furnace through the heat storage chamber is provided in pairs, and in the paired heat storage burner, the air supply pipe passes through the heat storage chamber. The combustion air is guided to the burner section, and the combustion operation in which fuel gas is injected from the fuel gas supply pipe in the burner section and burned, and the combustion exhaust gas in the heating furnace is guided to the heat storage chamber to reduce the heat of the combustion exhaust gas. There is used a heating furnace that alternately performs a heat storage operation in which heat is stored in a heat storage material and discharged from an exhaust gas discharge pipe.

  Here, in the heating furnace as described above, the temperature of the combustion exhaust gas guided to the exhaust gas exhaust pipe through the heat storage chamber is still a high temperature of about 200 ° C.

  Therefore, in recent years, as shown in Patent Documents 1 and 2, etc., in one livestock burner performing a heat storage operation, a part of the combustion exhaust gas led to the exhaust gas exhaust pipe through the heat storage chamber is burned. Supply the combustion air to the heat storage chamber of the other regenerative burner that is operating, supply the combustion air to the heat storage chamber through this air supply tube, and preheat the combustion air from the exhaust gas discharge pipe. It has been proposed to effectively use the heat of the exhaust gas discharged.

  Here, a part of the combustion exhaust gas guided to the exhaust gas exhaust pipe through the heat storage chamber is supplied to the air supply pipe for supplying combustion air to the heat storage chamber, and the combustion air guided to the heat storage chamber is preheated. In this case, the temperature of the combustion exhaust gas led to the heat storage chamber together with the combustion air by this air supply pipe becomes lower than about 110 ° C. which is the dew point of the combustion exhaust gas, and the combustion exhaust gas is condensed in this air supply pipe. As a result, the liquid becomes a liquid containing nitric acid, and the air supply pipe is eroded and damaged by the liquid.

Japanese Patent No. 3462394 Japanese Patent No. 3958942

  The present invention includes a burner section having 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 exhausting combustion exhaust gas in the heating furnace through the heat storage chamber. In a heating furnace provided with a pair of regenerative burners having an exhaust gas discharge pipe to be used, one heat storage type performing a heat storage operation in order to effectively use the heat of the combustion exhaust gas discharged from the exhaust gas discharge pipe In the burner, a part of the combustion exhaust gas led to the exhaust gas exhaust pipe through the heat storage chamber is supplied to an air supply pipe for supplying combustion air to the heat storage chamber of the other heat storage type burner performing the combustion operation. An object of the present invention is to solve the above-described problems in the case where combustion air guided to a heat storage chamber by a tube is heated in advance.

  That is, in the present invention, in one heat storage type burner performing a heat storage operation, a part of the combustion exhaust gas guided to the exhaust gas exhaust pipe through the heat storage chamber is used for the heat storage chamber of the other heat storage type burner performing the combustion operation. When the combustion air supplied to the heat storage chamber is supplied through the air supply pipe to the heat storage chamber in advance, the combustion air and the combustion exhaust gas guided to the heat storage chamber through the air supply pipe are supplied. Is appropriately heated to prevent the temperature of the combustion exhaust gas from becoming lower than the dew point of the combustion exhaust gas, and to suppress condensation of the combustion exhaust gas into a liquid containing nitric acid or the like in the air supply pipe. An object of the present invention is to appropriately prevent the supply pipe from being damaged by the liquid.

In the present invention, in order to solve the above-described problems, 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, A regenerative burner having a flue gas exhaust pipe for discharging the flue gas in the heating furnace through the heat storage chamber is provided as a pair, and an exhaust gas pipe for directly discharging a part of the flue gas in the heating furnace is provided. In the regenerative 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 burn, In a heating furnace that alternately conducts a heat storage operation in which 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 discharged from the exhaust gas discharge pipe, the exhaust gas is discharged from the exhaust gas discharge pipe. At least a portion of the combustion exhaust gas provided with an exhaust gas supply pipe leading to the air supply pipe of the being, the heat of the combustion exhaust gas in the exhaust gas pipe, provided with a waste heat transmission means for transmitting the combustion exhaust gas in the exhaust gas supply pipe.

In the heating furnace of the present invention, at least a part of the combustion exhaust gas discharged from the exhaust gas discharge pipe is guided to the air supply pipe by the exhaust gas supply pipe, and the combustion exhaust gas in the exhaust pipe is exhausted by the exhaust heat transfer means. This heat is transferred to the combustion exhaust gas in the exhaust gas supply pipe. In this case, the combustion exhaust gas guided from the exhaust gas exhaust pipe to the air supply pipe through the exhaust gas supply pipe is heated by the heat of the combustion exhaust gas in the exhaust gas pipe transmitted by the exhaust heat transfer means, and is burned by the air supply pipe. The temperature of the combustion exhaust gas guided to the heat storage chamber together with air is prevented from becoming lower than the dew point of the combustion exhaust gas.

Here, the heat of the combustion exhaust gas in the exhaust gas pipe, when providing the exhaust heat transmission means for transmitting the combustion exhaust gas in the exhaust gas supply pipe, for example, at least a part of the combustion exhaust gas discharged from the exhaust gas pipe, the exhaust gas supply pipe An exhaust gas introduction pipe to be introduced can be provided, or a heated air introduction pipe for introducing the air heated by the heat of the combustion exhaust gas in the exhaust gas pipe into the exhaust gas supply pipe can be provided.

When at least a part of the combustion exhaust gas discharged from the exhaust gas exhaust pipe is led to the air supply pipe by the exhaust gas supply pipe as in the heating furnace in this invention, the combustion air guided to the heat storage chamber by the air supply pipe is the combustion exhaust gas. When the heat of the combustion exhaust gas in the exhaust gas pipe is transmitted to the combustion exhaust gas in the exhaust gas supply pipe by the exhaust heat transfer means as described above, the combustion guided from the exhaust gas exhaust pipe to the air supply pipe through the exhaust gas supply pipe The exhaust gas is sufficiently heated by the heat of the combustion exhaust gas in the exhaust gas pipe transmitted by the exhaust heat transfer means.

  As a result, in the heating furnace according to the present invention, the temperature of the combustion exhaust gas guided to the heat storage chamber together with the combustion air by the air supply pipe is prevented from becoming lower than the dew point of the combustion exhaust gas. Is prevented from condensing and becoming a liquid containing nitric acid or the like, and the air supply pipe is prevented from being damaged by the liquid.

It is the schematic explanatory drawing which showed the structure of the heating furnace which concerns on one Embodiment of this invention. In the heating furnace which concerns on said embodiment, it is a schematic explanatory drawing of the example which changed the exhaust heat transmission means to which the heat of the combustion exhaust gas in an exhaust gas pipe is transmitted to the combustion exhaust gas in an exhaust gas supply pipe.

  Hereinafter, a heating furnace according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings. In addition, the heating furnace which concerns on this invention is not limited to what was shown to the following embodiment, In the range which does not change the summary of invention, it can implement by changing suitably.

  In the heating furnace 1 of this embodiment, as shown in FIG. 1, a pair of regenerative burners 10 a and 10 b are provided so as to face the inside of the heating furnace 1. An exhaust gas pipe 2 for exhausting a part of the combustion exhaust gas in the heating furnace 1 directly to the outside is provided at the top of the furnace.

  Moreover, in each said heat storage type burner 10a, 10b, the burner part 12a, 12b provided with fuel gas supply pipe | tube 11a, 11b, the heat storage chamber 14a, 14b which accommodated the heat storage material 13a, 13b, and the heat storage chamber 14a. , 14b are provided with air supply pipes 15a, 15b for supplying combustion air, and exhaust gas exhaust pipes 16a, 16b for discharging the combustion exhaust gas in the heating furnace 1 to the outside through the heat storage chambers 14a, 14b.

  The fuel gas supply pipes 11a and 11b are provided with fuel gas switching valves 17a and 17b for switching between supply and stop of the fuel gas to the burner portions 12a and 12b, and the air supply pipes 15a. , 15b are provided with combustion air switching valves 18a, 18b for switching supply / stop of combustion air to the respective heat storage chambers 14a, 14b, and the exhaust gas exhaust pipes 16a, 16b are provided with the respective heat storage chambers. Exhaust gas switching valves 19a and 19b are provided for switching between discharge and stop of combustion exhaust gas guided through 14a and 14b.

  Also, blowers 22 and 23 are connected to the air supply pipe 15 before branching to the air supply pipes 15a and 15b and the exhaust gas discharge pipe 16 where the exhaust gas discharge pipes 16a and 16b join, respectively. Air is supplied and combustion exhaust gas is discharged.

  In this embodiment, the above-described air supply pipe before the combustion exhaust gas guided to the exhaust gas exhaust pipe 16 joined by the exhaust gas exhaust pipes 16a and 16b is branched to the air supply pipes 15a and 15b. The exhaust gas supply pipe 20 led to the portion 15 is provided, and the exhaust gas supply adjustment valve 21 is provided in the exhaust gas supply pipe 20, and the exhaust gas supplied to the air supply pipe 15 through the exhaust gas supply pipe 20 by the exhaust gas supply adjustment valve 21 I am trying to adjust the amount.

Furthermore, in this embodiment, the heat of the combustion exhaust gas discharged from the exhaust gas pipe 2 is led from the heating furnace 1 to the exhaust gas pipe 2 as the exhaust heat transfer means 30 for transmitting the heat of the combustion exhaust gas to the combustion exhaust gas in the exhaust gas supply pipe 20. In addition, an exhaust gas introduction pipe 31 that guides high-temperature combustion exhaust gas of about 750 ° C. to the exhaust gas supply pipe 20 is provided, and an exhaust gas introduction adjustment valve 32 is provided in the exhaust gas introduction pipe 31. The amount of high-temperature combustion exhaust gas led from the exhaust gas pipe 2 to the exhaust gas supply pipe 20 through the exhaust gas introduction pipe 31 is adjusted.

  Next, a case where the combustion operation and the heat storage operation are alternately performed in the paired heat storage burners 10a and 10b provided in the heating furnace 1 of this embodiment will be described.

  Here, as shown in FIG. 1, in one regenerative burner 10a that performs a combustion operation, the exhaust gas switching valve 19a provided in the exhaust gas discharge pipe 16a that discharges the combustion exhaust gas through the heat storage chamber 14a is closed, while the heat storage material The combustion air switching valve 18a provided in the air supply pipe 15a for supplying combustion air to the heat storage chamber 14a in which 13a is accommodated is opened, and the air supply pipe 15 before branching is led to the air supply pipe 15a. The combustion air is introduced into the heat storage chamber 14a, and the combustion air is heated by the heat storage material 13a accommodated in the heat storage chamber 14a.

  The combustion air thus heated is ejected from the heat storage chamber 14a to the burner portion 12a, and the fuel gas switching valve 17a for supplying the fuel gas to the fuel gas supply pipe 11a is opened, and the fuel gas is supplied to the fuel gas. The fuel gas is injected from the supply pipe 11a to the burner section 12a, and the fuel gas is brought into contact with the combustion air heated as described above in the burner section 12a so as to be burned in the heating furnace 1.

  On the other hand, when performing the heat storage operation in the other heat storage type burner 10b, the fuel gas switching valve 17b for supplying the fuel gas to the fuel gas supply pipe 11b and the combustion air switching valve 18b provided in the air supply pipe 15b are closed. Avoid burning. On the other hand, the exhaust gas switching valve 19b provided in the exhaust gas exhaust pipe 16b for discharging the combustion exhaust gas through the heat storage chamber 14b is opened, the combustion exhaust gas in the heating furnace 1 is led to the heat storage chamber 14b, and the heat storage accommodated in the heat storage chamber 14b. After the heat of the combustion exhaust gas is stored in the material 13b, the combustion exhaust gas is guided from the exhaust gas exhaust pipe 16b to the exhaust gas exhaust pipe 16 where the exhaust gas exhaust pipes 16a and 16b merge. Here, after the heat is stored in the heat storage material 13b in this way, the temperature of the combustion exhaust gas guided to the exhaust gas exhaust pipe 16 is about 200 ° C. as described above.

  In this embodiment, the amount of combustion exhaust gas supplied from the exhaust gas discharge pipe 16 to the exhaust gas supply pipe 20 is adjusted by adjusting the opening and closing of the exhaust gas supply adjustment valve 21 provided in the exhaust gas supply pipe 20. An appropriate amount of combustion exhaust gas is guided through the exhaust gas supply pipe 20 to the portion of the air supply pipe 15 before branching to the air supply pipes 15a and 15b, and is provided in the exhaust gas introduction pipe 31. The amount by which the high-temperature combustion exhaust gas of about 750 ° C. discharged directly from the heating furnace 1 to the exhaust gas pipe 2 is led from the exhaust gas pipe 2 to the exhaust gas introduction pipe 31 by adjusting the opening and closing of the exhaust gas introduction adjusting valve 32. And an appropriate amount of high-temperature combustion exhaust gas is supplied to the exhaust gas supply pipe 20 through the exhaust gas introduction pipe 31, and the combustion exhaust gas guided to the air supply pipe 15 through the exhaust gas supply pipe 20 is controlled. And so as to increase the temperature of the nest.

  In this way, the temperature of the combustion exhaust gas guided together with the combustion air to the heat storage chambers 14a and 14b through the air supply pipes 15, 15a and 15b is suppressed from being below the dew point of the combustion exhaust gas, and the above air In the supply pipes 15, 15a, 15b, the combustion exhaust gas is prevented from condensing and becoming liquid containing nitric acid, and the air supply pipes 15, 15a, 15b are reliably prevented from being damaged by the liquid. Will come to be.

Further, in this embodiment, the exhaust heat transfer means 30 for transferring the heat of the combustion exhaust gas discharged from the exhaust gas pipe 2 to the combustion exhaust gas in the exhaust gas supply pipe 20 is a high temperature led from the heating furnace 1 to the exhaust gas pipe 2. The exhaust gas introduction pipe 31 that guides the combustion exhaust gas to the exhaust gas supply pipe 20 and the exhaust gas introduction adjustment valve 32 are provided in the exhaust gas introduction pipe 31, but the exhaust heat transfer means 30 is not limited to this.

For example, as shown in FIG. 2, air is guided from a blower 37 connected to an air introduction pipe 34 to a heat exchanger 33 provided around the exhaust pipe 2, and the air is exhausted in the heat exchanger 33. The heated air adjusting valve 36 can be provided in the heated air introduction pipe 35 that is heated by the heat of the combustion exhaust gas in the pipe 2 and guides the heated air to the exhaust gas supply pipe 20. Then, the amount of heated air led to the exhaust gas supply pipe 20 through the heated air introduction pipe 35 is adjusted by the heated air adjustment valve 36, and the above-described air is introduced into the exhaust gas supply pipe 20 and heated. The combustion exhaust gas guided to the air supply pipe 15 by the exhaust gas supply pipe 20 can be heated .

Further, in the exhaust heat transfer means 30 in the embodiment shown in FIGS. 1 and 2, the combustion exhaust gas discharged from the heating furnace 1 to the exhaust gas pipe 2 and the air heated by the heat of the combustion exhaust gas in the exhaust gas pipe 2 are used. The exhaust gas supply pipe 20 is directly supplied and heated. However, a heat exchanger (not shown) may be provided in the exhaust gas supply pipe 20 to indirectly heat it. .

DESCRIPTION OF SYMBOLS 1 Heating furnace 2 Exhaust gas pipe 10a, 10b Thermal storage type burner 11a, 11b Fuel gas supply pipe 12a, 12b Burner part 13a, 13b Thermal storage material 14a, 14b Thermal storage chamber 15, 15a, 15b Air supply pipe 16, 16a, 16b Exhaust gas exhaust pipe 17a, 17b Fuel gas switching valve 18a, 18b Combustion air switching valve 19a, 19b Exhaust gas switching valve 20 Exhaust gas supply pipe 21 Exhaust gas supply adjustment valve 22, 23 Blower 30 Exhaust heat transfer means 31 Exhaust gas introduction pipe 32 Exhaust gas introduction adjustment valve 33 Heat Exchanger 34 Air inlet pipe 35 Heated air inlet pipe 36 Heated air regulating valve 37 Blower

Claims (3)

A burner unit equipped 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 an exhaust gas exhaust pipe for discharging combustion exhaust gas in the heating furnace through the heat storage chamber And a heat storage burner having a pair, and an exhaust gas pipe for directly discharging a part of the combustion exhaust gas in the heating furnace is provided. In the paired heat storage burner, the air supply pipe passes through the heat storage chamber. The combustion air is guided to the burner section, and the combustion operation in which fuel gas is injected from the fuel gas supply pipe in the burner section and burned, and the combustion exhaust gas in the heating furnace is guided to the heat storage chamber to reduce the heat of the combustion exhaust gas. In a heating furnace that alternately performs a heat storage operation in which heat is stored in a heat storage material and discharged from an exhaust gas discharge pipe, at least a part of the combustion exhaust gas discharged from the exhaust gas discharge pipe is transferred to the air supply pipe Ku provided with an exhaust gas supply pipe, a heating furnace, characterized in that the heat of the combustion exhaust gas in the exhaust gas pipe, provided with a waste heat transmission means for transmitting the combustion exhaust gas in the exhaust gas supply pipe. The heating furnace according to claim 1, wherein an exhaust gas introduction pipe for introducing at least a part of the combustion exhaust gas discharged from the exhaust gas pipe into the exhaust gas supply pipe is provided as the exhaust heat transfer means. A heating furnace. The heating furnace according to claim 1, wherein a heating air introduction pipe for introducing air heated by heat of combustion exhaust gas in the exhaust gas pipe into the exhaust gas supply pipe is provided as the exhaust heat transfer means. A featured heating furnace.

Images