JP2016142442A - Alternate combustion burner device and heating furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an alternate combustion burner device capable of elongating a combustion time of actual combustion of burners, shortening a time necessary for heating in a furnace, and suppressing early failure of mechanical components operated in switching the burners, such as a selector valve and a spark rod used in ignition of the burners by reducing the number of times of switching of the burners.SOLUTION: An alternate combustion burner device constituted by disposing heat storage chambers provided with heat storage bodies respectively on a pair of burners 1a, 1b constituted to form flame, alternately burning the pair of burners 1a, 1b by every switching time, and recovering exhaust heat to the heat storage chamber disposed on one of the burners during the combustion of the other burner, further includes an exhaust temperature sensor for measuring a temperature Tpe of a combustion exhaust gas after recovering exhaust heat, and a control portion for burning the same burner until the temperature Tpe measured by the exhaust temperature sensor reaches a predetermined threshold value Tp0, and switching the burner to be burned at a timing of reaching the threshold value.SELECTED DRAWING: Figure 3

Description

  The present invention provides a heat storage chamber in which a heat storage body is provided in each of a pair of burners configured to form a flame, and alternately burns the pair of burners for each switching time, and during combustion of one of the burners The present invention relates to an alternating combustion burner apparatus configured to recover exhaust heat in the heat storage chamber provided in the other burner, and a heating furnace using the apparatus.

  A regenerative burner system (alternate combustion burner device) that realizes energy saving and cost saving by alternately burning a pair of burners integrated with a heat storage body is known. In the regenerative burner system, when one burner is burning, the exhaust gas passes through the heat storage body of the other burner and is heated. Thereby, when the burner integrated with the heated heat storage body burns, the combustion air is preheated by the heat storage body. In other words, combustion can be performed with high efficiency by recovering the energy of the exhaust gas that has been discarded in the past by the heat storage body.

  Conventionally, as a burner combustion control method in such a regenerative burner system, the burner to be burned is switched every predetermined switching time from the time of ignition of the burner until the temperature of the furnace is increased to a target temperature. If this switching time becomes longer, the exhaust temperature to the burner on the non-combustion side rises, and there is a possibility of failure such as burning of the burner, piping, and heat storage body, so it cannot be made unnecessarily long. As shown in paragraph 0032, it was customarily set to about 30 seconds.

JP 2013-210169 A

  However, in the regenerative burner system, the burner switching operation itself takes about 3 to 5 seconds. That is, the time when the burner is not burned occurs. For this reason, when the switching time is set to 30 seconds and the switching operation of the burner requires 3 seconds, the burner combustion time in the system operating time is about 30 / 33≈91%. Therefore, compared with the output when the burner is burned for 100% (rated output), the output is reduced, and the time required for the temperature rise of the furnace is increased. Furthermore, when the switching time is set short, the number of times of switching of the burner is larger than when the switching time is set long, so the number of times of driving of the mechanical parts such as the switching valve related to the switching of the burner is increased, resulting in early failure. There is a problem of inviting.

  Accordingly, an object of the present invention is to increase the combustion time that the burner can actually burn, shorten the time required for heating in the furnace, and reduce the number of times the burner is switched, thereby reducing the spark used for switching valve and burner ignition. An object of the present invention is to realize an alternating combustion burner device that can suppress early failure of mechanical parts that are operated when the burner is switched, such as a rod.

A characteristic configuration of the alternating combustion burner device according to the present invention is that a pair of burners configured to form a flame is provided with a heat storage chamber provided with a heat storage body, and the pair of burners are alternately burned for each switching time. In addition, during combustion of one of the burners, in the alternating combustion burner device configured to recover exhaust heat in the heat storage chamber provided in the other burner,
An exhaust temperature sensor for measuring the temperature of the combustion exhaust gas after the exhaust heat is recovered;
A control unit that burns the same burner until the temperature measured by the exhaust temperature sensor reaches a predetermined threshold, and switches the burner to be burned when the threshold is reached.

According to the above characteristic configuration, when the temperature measured by the exhaust temperature sensor is low, the time (switching time) during which one of the burners is burned becomes longer. Therefore, when the temperature in the furnace is low (for example, from when the burner is ignited until the temperature in the furnace is increased to the target temperature), the measured temperature continues to be low, and the operation of the alternating combustion burner device is continued. In time, the time to actually burn the burner increases. Thereby, the actual burner combustion time becomes longer than the time required for the burner switching operation, and the time required for heating in the furnace can be shortened.
Furthermore, since the burner switching time is lengthened, the number of burner switchings per unit time can be reduced.
In addition, when the temperature in the furnace is low, the exhaust temperature of the other burner (burned burner) is low, so even if the switching time is longer than when the temperature in the furnace is high, the burner and the heat storage body It is unlikely that burning will occur.
As described above, the burn time that the burner can actually burn is lengthened, the time required for heating in the furnace can be shortened, and the number of times the burner is switched is reduced, so that when the burner is switched, such as a spark rod used for ignition of the burner. An alternating combustion burner device that can suppress early failure of the machine parts to be operated can be realized.

A further characteristic configuration includes a blowing means for supplying combustion air into the furnace through the heat storage chamber of the burner,
Exhaust means for exhausting combustion exhaust gas from the furnace through the heat storage chamber of the burner;
A state in which the blower means is connected to one of the burners, and the exhaust means is connected to the other burner, and a state in which the exhaust means is connected to one of the burners and the blower means is connected to the other burner. And a switching valve for switching between.

  According to the above characteristic configuration, as described above, the combustion time that the burner can actually burn is lengthened, the time required for heating in the furnace can be shortened, and the number of times the burner is switched can be reduced. Thereby, the alternating combustion burner apparatus which can suppress the early failure of machine parts, such as a switching valve, is realizable.

  Moreover, the characteristic structure of the heating furnace which concerns on this invention exists in the point which is a batch type heating furnace provided with the above-mentioned alternating combustion burner apparatus.

  According to the above characteristic configuration, in the batch-type heating furnace, when an object to be heat-treated is put into the furnace, the temperature in the furnace decreases due to factors such as the outside air entering the furnace. Here, by providing the above-described alternating combustion burner device, the combustion time during which the burner can actually be burned is increased, and the time required for heating in the furnace can be shortened. Therefore, even when the temperature in the furnace decreases, the inside of the furnace can be quickly reheated. Therefore, the time required for the heat treatment of the heat treatment object can be shortened, and high production efficiency can be realized during batch processing.

Configuration diagram of alternating combustion burner Thermal storage combustion burner configuration diagram Diagram showing burner switching timing External view of heating furnace

1. Schematic configuration of alternating combustion burner apparatus Hereinafter, an example of an embodiment of an alternating combustion burner apparatus B according to the present invention will be described based on the drawings.

  As shown in FIG. 1, the alternating combustion burner device B includes a pair of regenerative combustion burners 1 (1a, 1b), a combustion mode in which one burner 1 is in a combustion state and the other burner 1 is in a heat storage state. Repeat alternately.

  In the present embodiment, the glass material is charged into the alternating combustion furnace F, and the glass material is melted by the pair of regenerative combustion burners 1. Here, “glass raw material” corresponds to the object to be heated, and “melting of the glass raw material” corresponds to the heat treatment. Further, as shown in FIG. 4, the side wall of the alternating combustion furnace F is provided with a door 9 for charging the glass raw material into the alternating combustion furnace F and taking out the molten glass from the furnace. The alternating combustion furnace F is configured as a so-called batch-type heating furnace.

  Here, the regenerative combustion burner 1 in the combustion state burns the supplied fuel gas G, and forms a flame in the alternating combustion furnace F. On the other hand, in the heat storage combustion burner 1 in the heat storage state, the supply of the fuel gas G is stopped, the combustion exhaust gas E generated by the flame formed by the heat storage combustion burner 1 in the combustion state is taken in, and the heat storage chamber 3c (see FIG. 2) The exhaust heat is recovered by the heat storage body provided in the.

  The heat storage body provided in the heat storage chamber 3c includes combustion air A supplied into the alternating combustion furnace F from the blower fan 2a and combustion exhaust gas E discharged from the alternating combustion furnace F into the exhaust fan 2b. It is configured to be able to exchange heat by passing and contacting. That is, the combustion air A is supplied into the alternating combustion furnace F in a preheated state by the heat storage body of the heat storage chamber 3c.

  As shown in FIG. 2, a pair of burners 1a and 1b in the alternating combustion burner apparatus B are installed on the furnace wall F1 of the alternating combustion furnace F, and the through-hole F2 is formed in the burner tile installed in the furnace wall F1. And a burner nozzle 1n provided with a supply / exhaust unit 3 and a fuel supply unit 4 is inserted. In addition, the installation location of the burners 1a and 1b may be provided on the facing furnace wall F1, or may be provided in parallel on the same furnace wall F1. The burner nozzle 1n is formed in a cylindrical shape, includes a fuel supply unit 4 at the center of the cylinder, and includes an air supply / exhaust unit 3 outside the fuel supply unit 4.

2. Thermal Storage Combustion Burner As shown in FIG. 2, the thermal storage combustion burner 1 includes a supply / exhaust unit 3 that functions as a combustion air supply unit through which combustion air A passes and a combustion exhaust gas exhaust unit through which combustion exhaust gas E passes. The alternating combustion burner device B is supplied with combustion air A in the alternating combustion furnace F and at the tip of the burner 1 via a supply / exhaust unit 3 as a combustion air supply unit, and a supply / exhaust unit as a combustion exhaust gas exhaust unit The combustion exhaust gas E in the alternating combustion furnace F is exhausted through 3.

  Furthermore, the regenerative combustion burner 1 includes a fuel supply unit 4 that supplies the fuel gas G into the alternating combustion furnace F. A heat storage chamber 3c is provided in communication with the air supply / exhaust section 3. The heat storage chamber 3c is provided from the air supply / exhaust section 3 to the tip of the burner 1, and is filled with a heat storage body. The fuel supply unit 4 is connected to the outside of the furnace wall F1 by providing a fuel valve (not shown).

  In the present embodiment, the alternating combustion burner device B includes an exhaust temperature sensor 8 that can measure the exhaust temperature Tpe of the combustion exhaust gas E after the exhaust heat is recovered. Specifically, the exhaust gas temperature sensor 8 measures the exhaust gas temperature Tpe of the combustion exhaust gas E discharged from the air supply / exhaust unit 3. FIG. 1 shows a case where the exhaust temperature sensor 8 is provided between the switching valve V and the exhaust fan 2b. It should be noted that the exhaust temperature sensor 8 may be provided on the downstream side of the air supply / exhaust unit 3, and more preferably on the downstream side of the switching valve V.

  As shown in FIG. 1, the pair of regenerative combustion burners 1 is configured such that a blower fan 2 a or an exhaust fan 2 b is connected to each air supply / exhaust unit 3 via a switching valve V. The blower fan 2a, the exhaust fan 2b, and the switching valve V are controlled by the control unit 6, and the blower fan 2a or the exhaust fan 2b is connected to which of the pair of regenerative combustion burners 1 by the operation of the switching valve V. It changes.

  That is, the combustion state and the heat storage state of the pair of heat storage combustion type burners 1 are switched by the switching valve V. Here, the supply / exhaust part 3 of the burner 1 to which the blower fan 2a is connected functions as a combustion air supply part, and the supply / exhaust part 3 of the regenerative combustion burner 1 to which the exhaust fan 2b is connected is the combustion exhaust gas exhaust part. Work as. With such a configuration, the recovery of the exhaust heat of the combustion exhaust gas E and the preheating of the combustion air A are performed simultaneously.

  Here, the blower fan 2a corresponds to “blower”, and the exhaust fan 2b corresponds to “exhaust”.

  The heat storage combustion type burner 1 is provided with a pilot burner 7 for igniting when shifting to the combustion state, and the pilot burner 7 includes the fuel gas G and the combustion gas regardless of the combustion state or the heat storage state. Air A is supplied and operated to form a fire.

3. Adjustment of Burner Switching Timing The control unit 6 controls the blower fan 2a, the exhaust fan 2b, and the switching valve V based on the exhaust temperature Tpe measured by the exhaust temperature sensor 8, and controls the pair of burners 1a and 1b. Adjust the timing for burning.

  A method for controlling the switching timing of the pair of regenerative combustion burners 1 will be described with reference to FIG. In the graph of FIG. 3, the horizontal axis indicates the elapsed time since the start of combustion in the alternating combustion furnace F, and the vertical axis indicates the exhaust temperature Tpe measured by the exhaust temperature sensor 8. Moreover, the burner 1 which burns in each time is shown in the upper part of the graph. More specifically, the temperature change in the alternating combustion furnace F in the initial stage until the temperature in the alternating combustion furnace F is heated to the target temperature is shown. That is, the temperature change at the initial stage where one batch process is started is shown.

  In the figure, “T, Tx” indicates the switching time during which any one of the pair of regenerative combustion burners 1 is burning, and “Ts” indicates the time required for the switching operation of the regenerative combustion burner 1. . The graph shown in FIG. 3 is not an actual measurement value but an image diagram for explaining the present invention.

  The control unit 6 burns the same burner 1 until the exhaust temperature Tpe measured by the exhaust temperature sensor 8 reaches a predetermined threshold value Tp0, and switches the burner 1 to be burned when the threshold value Tp0 is reached.

  Here, the threshold value Tp0 is set to 450 ° C., for example. Note that the temperature set as the threshold value Tp0 is as much as possible within a range in which the member does not burn out based on the heat resistance performance of the member through which the combustion exhaust gas E passes (such as the heat storage body provided in the heat storage chamber 3c or the switching valve V). A high temperature should be set.

  As shown in the example of FIG. 3, by performing such control, when the furnace temperature is low at the start of combustion of the burner 1 (particularly from when the burner is ignited until the temperature in the furnace is increased to a target temperature). In the meantime, the switching time T can be lengthened. That is, until the exhaust gas temperature Tpe reaches the threshold value Tp0, the furnace can be continuously heated without switching the burner 1, so that the burner burns at predetermined intervals as in the prior art. Compared with the case where 1 is switched, the time required for raising the temperature of the furnace can be shortened.

  In addition, since the pair of regenerative combustion burners 1 is not switched before the exhaust temperature Tpe reaches the threshold value Tp0, wear of the switching valve V that is operated when switching the burner 1 to be burned can be suppressed. .

  As described above, the combustion time that the regenerative combustion burner 1 can actually burn is lengthened, the time required for heating in the furnace can be shortened, and the switching valve V or An alternating combustion burner apparatus B that can suppress an early failure of a mechanical component that is operated when the burner 1 is switched can be realized.

[Another embodiment]
(1) In the said embodiment, although the example in the case of using a glass melting furnace as an alternating combustion burner apparatus B was shown, if it is a heating furnace which performs alternating combustion, other uses, such as a glass melting furnace and a metal melting furnace The furnace may be used.

(2) In the above-described embodiment, an example in which the regenerative combustion burner 1 includes the pilot burner 7 has been shown. Absent.

(3) In the above embodiment, an example in which the regenerative combustion burner 1 forms a flame in the alternating combustion furnace F has been shown. However, a pair of regenerative combustion burners 1 are radiant tubes in the alternating combustion furnace F. It is also possible to adopt a configuration (so-called regenerative radiant tube burner) that is connected in communication and forms a flame within the radiant tube.

  In this case, since the exhaust temperature Tpe is kept relatively low compared to the threshold value Tp0, the pair of regenerative combustion burners 1 are kept in contact with the combustion exhaust gas E in a state where they are connected by a radiant tube. Is also preferable because it is less likely to cause burnout of the burner 1.

1: Thermal storage combustion type burner 1a: Burner 1b: Burner 2a: Blower fan (blower means)
2b: Exhaust fan (exhaust means)
3c: Heat storage chamber 6: Control unit 8: Exhaust temperature sensor A: Combustion air B: Alternate combustion burner device E: Combustion exhaust gas F: Alternate combustion furnace Tp0: Threshold value Tpe: Exhaust temperature V: Switching valve

Claims (3)

Each of the pair of burners configured to form a flame is provided with a heat storage chamber provided with a heat storage body, and the pair of burners are alternately burned for each switching time, and during the combustion of one of the burners, the other In the alternating combustion burner device configured to recover exhaust heat in the heat storage chamber provided in the burner,
An exhaust temperature sensor for measuring the temperature of the combustion exhaust gas after the exhaust heat is recovered;
An alternating combustion burner apparatus comprising: a control unit that switches the burner to burn at the timing when the same burner is burned until the temperature measured by the exhaust temperature sensor reaches a predetermined threshold value . An air blowing means for supplying combustion air into the furnace through the heat storage chamber of the burner;
Exhaust means for exhausting combustion exhaust gas from the furnace through the heat storage chamber of the burner;
A state in which the blower means is connected to one of the burners, and the exhaust means is connected to the other burner, and a state in which the exhaust means is connected to one of the burners and the blower means is connected to the other burner. The alternating combustion burner device according to claim 1, further comprising: a switching valve that switches between the two.   A batch-type heating furnace using the alternating combustion burner device according to claim 1.

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