JP2008249280A - Gas burner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas burner capable of keeping a discharge amount of CO small irrespective of a temperature level in a heating furnace and forming a stable pilot flame. <P>SOLUTION: The gas burner 1 has a pilot air pipe 2, a pilot gas pipe 3, a main gas pipe 4, and a refractory body 7. A pilot air passage 71 is formed between a through hole 70 of the refractory body 7 and the pilot air pipe 2. The pilot air pipe 2 is formed with a pilot air ejecting hole 21 ejecting a part of an pilot air A2 passing through the pilot air pipe 2 into the pilot air passage 71. A mixture G of the pilot air A2 in the pilot air pipe 2 and a pilot gas F2 is ejected from a leading end of the pilot air pipe 2, and the pilot air A2 ejected from a leading end of the pilot air passage 71 is supplied to a pilot flame H formed by combustion of the mixture G. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a gas burner configured to burn a pilot gas with pilot air to form a pilot flame and to burn a main gas by the pilot flame to form a main flame.

  Conventionally, when the inside of a heating furnace is heated using a gas burner, the main gas is burned using a pilot flame. For example, in Patent Document 1, an inner cylinder through which pilot gas passes is inserted into an outer cylinder through which pilot air passes, and a main fuel pipe through which main fuel is injected is inserted into the inner cylinder. Thus, a triple-pipe fuel injection gun is constructed. According to this, it is not necessary to provide a pilot burner separately from the main burner, and the structure of the entire burner can be made compact and simple.

  By the way, when a regenerative burner or the like that performs alternating combustion using a pair of gas burners (repeating alternately combustion and exhaust) is formed in a heating furnace, a pilot flame is always formed to quickly ignite the main fuel. It is possible to do it stably. In the exhaust-side gas burner, the combustion gas forming the pilot flame may be exhausted together with the exhaust gas exhausted from the heating furnace. In this case, the exhaust amount of CO (carbon monoxide) in the exhaust gas increases.

Therefore, in order to reduce the amount of CO exhaust in the exhaust gas, it is conceivable to increase the air ratio of the pilot air to the pilot gas and sufficiently burn the pilot gas. If the air ratio of pilot air to pilot gas is increased, the amount of CO exhaust can be reduced after the heating furnace reaches a high temperature (for example, about 1000 to 1100 ° C.).
However, in a low temperature state before the heating furnace reaches a high temperature, the air ratio is large, the combustion of the pilot gas is not stable, and it becomes difficult to stably form the pilot flame.

JP-A-10-68510

  The present invention has been made in view of such conventional problems. A gas burner capable of stably forming a pilot flame while suppressing CO emission to a small extent regardless of the temperature in the heating furnace. It is something to be offered.

The present invention includes a pilot air pipe that allows pilot air to pass through, a pilot gas pipe that passes through the pilot air pipe and passes pilot gas, a main gas pipe that passes through the pilot gas pipe and passes main gas, and the periphery of the pilot air pipe And a fireproof body that covers
The tip of the pilot gas pipe is closed by the tip of the main gas pipe, and the pilot gas pipe has a pilot gas ejection hole for mixing the pilot gas into the pilot air pipe,
The pilot air pipe is disposed in an insertion hole formed in the fireproof body, and a pilot air passage is formed between an inner peripheral surface of the insertion hole and an outer peripheral surface of the pilot air pipe,
The pilot air pipe has a pilot air ejection hole for ejecting a portion of the pilot air that passes through the pilot air pipe into the pilot air passage.
From the tip of the pilot air pipe, an air-fuel mixture obtained by mixing the pilot gas into the pilot air in the pilot air pipe is ejected, and the pilot air that is formed by combustion of the air-fuel mixture is introduced into the pilot air. The gas burner is configured to supply the pilot air that is ejected from the front end portion of the passage (claim 1).

  According to the gas burner of the present invention, the formation of the pilot air passage and the pilot air injection hole suppresses the amount of CO (carbon monoxide) emission to be small and stabilizes regardless of the temperature in the heating furnace to which the gas burner is attached. Thus, a pilot flame can be formed.

  When the pilot flame is formed in the gas burner of the present invention, the pilot gas passes through the pilot gas pipe and the pilot air passes through the pilot air pipe. At this time, part of the pilot air that passes through the pilot air pipe is jetted into the pilot air passage from the pilot air jet hole, passes through the pilot air passage, and is jetted from the tip portion thereof.

On the other hand, the pilot gas passing through the pilot gas pipe is ejected from the pilot gas ejection hole into the pilot air pipe and mixed with the pilot air in the pilot air pipe. The air-fuel mixture created by this mixed flow is ejected from the tip of the pilot air pipe, and the formation of the pilot flame is started by the combustion of the air-fuel mixture.
The pilot air ejected from the tip of the pilot air passage is supplied to the pilot flame.

  Thereby, formation of the pilot flame can be started by the first air ratio as the flow rate of the pilot air ejected from the tip of the pilot air pipe with respect to the flow rate of the pilot gas ejected from the pilot gas ejection hole. Therefore, the first air ratio when starting formation of the pilot flame (starting combustion of the pilot gas) can be reduced. For example, even when the temperature in the heating furnace is low, the pilot gas is stably ignited. Thus, the formation of the pilot flame can be started stably.

  Also, pilot air that is ejected from the tip of the pilot air passage is supplied to the pilot flame, so that the pilot flame as a whole has a flow rate of pilot air that is ejected from the tip of the pilot air pipe and the tip of the pilot air passage. The second air ratio as a sum of the flow rate of the pilot air ejected from the air can be formed. Therefore, the second air ratio at the time of forming the entire pilot flame can be maintained large, for example, when the temperature in the heating furnace is low and high, the pilot gas is sufficiently burned, The amount of CO (carbon monoxide) exhaust can be reduced.

  Therefore, according to the gas burner of the present invention, the amount of CO emission can be suppressed to a small level and a pilot flame can be formed stably regardless of the temperature inside the heating furnace.

A preferred embodiment of the present invention described above will be described.
In the present invention, the flow rate of the pilot air ejected from the front end portion of the pilot air pipe is larger than the flow rate of the pilot air ejected from the front end portion of the pilot air passage, and is ejected from the pilot gas ejection hole. With respect to the flow rate of the pilot gas, the air ratio (the value obtained by dividing the actually supplied air amount by the amount of air required for complete combustion of the fuel gas) is 0.6 to 1.4. It is preferable to set (Claim 2).

In this case, the formation of the pilot flame can be started more stably, and the amount of CO exhaust can be suppressed to a smaller level. In addition, it is more preferable that the air ratio of the pilot air ejected from the tip of the pilot air pipe is 1 to 1.2.
The flow rate of the pilot air ejected from the tip of the pilot air passage is set to a flow rate at which the air ratio is 0.1 to 0.6 with respect to the pilot gas ejected from the pilot gas ejection hole. Is preferred. In addition, the total flow rate of the pilot air ejected from the tip of the pilot air pipe and the tip of the pilot air passage is 1 or more with respect to the pilot gas ejected from the pilot gas ejection hole. It is preferable to set the flow rate.

Further, a flange portion projecting radially outward in the pilot air pipe is formed at a tip portion of the pilot gas pipe, and an air-fuel mixture ejection groove for ejecting the air-fuel mixture is circumferentially formed in the flange portion. It is preferable that the pilot flame is started to be formed in the vicinity of the downstream side of the position where the air-fuel mixture ejection groove is formed (Claim 3).
In this case, a plurality of pilot flames can be formed by combustion of the air-fuel mixture ejected from the plurality of air-fuel mixture ejection grooves, and this pilot flame can be formed more stably.

The fireproof body is formed with a main air passage through which combustion air is ejected, and the main gas ejected from the front end portion of the main gas pipe is ignited by the pilot flame, and from the front end portion of the main air passage. It is preferable to combust with the combustion air to be ejected (claim 4).
In this case, the main gas can be stably ignited by the pilot flame, and the main gas can be stably combusted with the combustion air.

Hereinafter, embodiments of the gas burner of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the gas burner 1 of this example includes a pilot air pipe 2 that allows pilot air A2 to pass through, a pilot gas pipe 3 that passes through the pilot air pipe 2 and passes pilot gas F2, and a pilot gas pipe 3 that passes through the main. A main gas pipe 4 through which the gas F1 passes and a fireproof body (burner tile) 7 covering the periphery of the pilot air pipe 2 are provided.

  As shown in FIGS. 2 to 4, the tip of the pilot gas pipe 3 is closed by the tip of the main gas pipe 4, and the pilot gas pipe 3 has a pilot gas for mixing the pilot gas F <b> 2 into the pilot air pipe 2. An ejection hole 31 is formed. The pilot air pipe 2 is disposed in an insertion hole 70 formed in the fireproof body 7, and a pilot air passage 71 is formed between the inner peripheral surface of the insertion hole 70 and the outer peripheral surface of the pilot air pipe 2. .

  The pilot air pipe 2 is formed with a pilot air ejection hole 21 through which a part of the pilot air A2 passing through the pilot air pipe 2 is ejected into the pilot air passage 71. The gas burner 1 of this example is formed by jetting an air-fuel mixture G in which the pilot gas F2 is mixed into the pilot air A2 in the pilot air pipe 2 from the tip of the pilot air pipe 2 and burning the air-fuel mixture G. The pilot air A2 ejected from the tip of the pilot air passage 71 is supplied to the pilot flame H to be started.

Hereinafter, the gas burner 1 of this example will be described in detail with reference to FIGS.
The gas burner 1 of the present example has a pilot air passage 71 and a pilot air injection hole 21 so that the amount of CO (carbon monoxide) emission can be reduced and the pilot can be stably controlled regardless of the temperature inside the heating furnace. A flame H can be formed.
The gas burner 1 of this example is disposed as a pair with respect to the heating furnace and used as a regeneration burner configured to alternately perform combustion and exhaust.

As shown in FIG. 1, the rear end portion of the pilot air pipe 2, the rear end portion of the pilot gas pipe 3, and the rear end portion of the main gas pipe 4 of this example are attached to a burner body 6 disposed outside the heating furnace. The burner body 6 includes a pilot air introduction part 61 for introducing pilot air A 2 into the pilot air pipe 2, a pilot gas introduction part 62 for introducing pilot gas F 2 into the pilot gas pipe 3, and the inside of the main gas pipe 4. A main gas introduction part 63 for introducing the main gas F1 is formed.
In addition, the pilot air A2 and the combustion air A1 in this example are fresh air (air), and the main gas F1 and the pilot gas F2 in this example are city gas (13A and the like), LPG, and the like.
In this example, the front end side refers to the inside of the heating furnace, and the rear end side refers to the outside of the heating furnace.

  The refractory body 7 is formed with a main air passage 72 through which the combustion air A1 is ejected. In the main air passage 72, the exhaust heat of the exhaust gas after heating the inside of the heating furnace is recovered. A heat storage body 73 is disposed. The refractory body 7 is configured by disposing a heat-resistant material such as heat-resistant ceramics in a metal body. An annular projecting wall 74 is formed on the tip side surface of the refractory body 7 around the portion where the insertion hole 70 is formed.

  As shown in FIG. 2, a main gas nozzle 41 for ejecting the main gas F <b> 1 passing through the main gas pipe 4 is formed at the tip of the pilot gas pipe 3. A main gas outlet 411 formed in the main gas nozzle 41 is formed in parallel to the axial direction L of the main gas pipe 4. Further, the main gas outlet 411 may be formed to be inclined with respect to the axial direction L of the main gas pipe 4 so that the main gas F <b> 1 is ejected in the direction of the main air passage 72.

  Further, as shown in FIG. 3, the pilot air ejection holes 21 are formed at a plurality of locations in the circumferential direction C in the vicinity of the rear end portion of the pilot air pipe 2. As shown in FIG. 4, the pilot gas ejection holes 31 are formed at a plurality of locations in the circumferential direction C in the vicinity of the tip of the pilot gas pipe 3.

As shown in FIGS. 2 and 4, a flange portion 32 that protrudes radially outward in the pilot air pipe 2 and contacts the inner peripheral surface of the pilot air pipe 2 is formed at the tip of the pilot gas pipe 3. A plurality of air-fuel mixture ejection grooves 321 for ejecting an air-fuel mixture G formed by mixing pilot air A2 and pilot gas F2 are formed in the flange portion 32 in the circumferential direction C. The air-fuel mixture ejection groove 321 is formed so as to be inclined in the circumferential direction C of the flange portion 32, and the air-fuel mixture G ejected from the air-fuel mixture ejection groove 321 is swirled.
In addition, a spark rod 15 that generates sparks is disposed in the pilot air pipe 2, and the front end portion of the spark rod 15 protrudes from the front end surface of the flange portion 32 of the pilot gas pipe 3.

  The passage of the pilot gas F <b> 2 in the pilot gas pipe 3 is formed in an annular shape between the inner peripheral surface of the pilot gas pipe 3 and the outer peripheral surface of the main gas pipe 4. The pilot air A 2 passage in the pilot air pipe 2 is formed in an annular shape between the inner peripheral surface of the pilot air pipe 2 and the outer peripheral surface of the pilot gas pipe 3. The pilot air passage 71 is formed in an annular shape between the inner peripheral surface of the insertion hole 70 in the fireproof body 7 and the outer peripheral surface of the pilot air pipe 2.

The cross-sectional area of the pilot air A2 passage in the pilot air pipe 2 is larger than the cross-sectional area of the pilot air passage 71, and the flow rate of the pilot air A2 ejected from the tip of the pilot air pipe 2 is the pilot air The flow rate of the pilot air A2 ejected from the tip of the passage 71 is increased.
In this example, the flow rate of the pilot air A2 ejected from the tip end portion of the pilot air pipe 2 is the air ratio (the amount of air actually supplied is calculated theoretically with respect to the flow rate of the pilot gas F2 ejected from the pilot gas ejection hole 31. The value obtained by dividing the amount of air required for complete combustion of the fuel gas is approximately 1.1. The flow rate of the pilot air A2 ejected from the tip of the pilot air passage 71 is set to a flow rate at which the air ratio is about 0.3 with respect to the flow rate of the pilot gas F2 ejected from the pilot gas ejection hole 31. is there. The air ratio of the entire pilot air A2 to the pilot gas F2 is set to about 1.4.

  When the pilot flame H is formed in the gas burner 1 of this example, the pilot gas F2 passes through the pilot gas pipe 3, and the pilot air A2 passes through the pilot air pipe 2. At this time, a part of the pilot air A2 that passes through the pilot air pipe 2 is jetted into the pilot air passage 71 from the plurality of pilot air ejection holes 21, passes through the pilot air passage 71, and from the tip thereof. Erupted.

On the other hand, the pilot gas F2 passing through the pilot gas pipe 3 is ejected into the pilot air pipe 2 from the plurality of pilot gas ejection holes 31 and mixed with the pilot air A2 in the pilot air pipe 2. The mixture G created by this mixed flow is ejected from a plurality of mixture ejection grooves 321 in the flange portion 32 of the pilot air pipe 2, and the combustion of the mixture G corresponds to the formation position of the mixture ejection grooves 321. The formation of the pilot flame H is started near the downstream side of the air-fuel mixture ejection groove 321.
Pilot air A <b> 2 ejected from the tip of the pilot air passage 71 is supplied to the pilot flame H.

  Thereby, formation of the pilot flame H is started by the first air ratio as the flow rate of the pilot air A2 ejected from the tip of the pilot air pipe 2 with respect to the flow rate of the pilot gas F2 ejected from the pilot gas ejection hole 31. be able to. Therefore, the first air ratio when starting formation of the pilot flame H (starting combustion of the pilot gas F2) can be reduced. For example, even when the temperature in the heating furnace is low, the pilot gas F2 is stable. Thus, the pilot flame H can be stably started.

  Further, the pilot flame A is supplied to the pilot flame H from the front end portion of the pilot air passage 71, so that the pilot flame H as a whole has a flow rate of the pilot air A2 ejected from the front end portion of the pilot air pipe 2, and It can be formed by the second air ratio as the sum of the flow rate of the pilot air A2 ejected from the tip of the pilot air passage 71. Therefore, the second air ratio at the time of forming the entire pilot flame H can be maintained large. For example, the pilot gas F2 can be sufficiently burned even when the temperature in the heating furnace is low or high. Thus, the amount of CO (carbon monoxide) exhaust can be reduced.

  Therefore, according to the gas burner 1 of the present example, it is possible to suppress the CO emission amount to a small level and to stably form the pilot flame H regardless of the temperature in the heating furnace.

  Further, when performing alternating combustion with the pair of gas burners 1, in the combustion-side gas burner 1, the main gas F1 ejected from the main gas outlet 411 of the main gas nozzle 41 is ignited by the plurality of pilot flames H, Combustion can be performed together with combustion air A <b> 1 ejected from the tip of the main air passage 72. And the main gas F1 can be stably burned using the exhaust heat collected by the heat storage body 73 in the main air passage 72, and a main flame by this combustion can be formed. Moreover, when performing the said alternating combustion, the pilot flame H can always be formed in both the combustion side and the gas burner 1 of an exhaust side.

Cross-sectional explanatory drawing which shows the gas burner in an Example. Cross-sectional explanatory drawing which expands and shows a part of gas burner in an Example. It is a figure which shows a part of gas burner in an Example, and is AA arrow directional cross-sectional explanatory drawing in FIG. It is a figure which shows a part of gas burner in an Example, and is B line arrow directional cross-sectional explanatory drawing in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas burner 2 Pilot air pipe 21 Pilot air ejection hole 3 Pilot gas pipe 31 Pilot gas ejection hole 32 Flange part 321 Mixture ejection groove 4 Main gas pipe 41 Main gas nozzle 411 Main gas ejection port 6 Burner body 7 Fireproof body 70 Insertion hole 71 Pilot air passage 72 Main air passage 73 Heat storage body A1 Combustion air A2 Pilot air F1 Main gas F2 Pilot gas G Mixture H Pilot flame

Claims (4)

A pilot air pipe that allows pilot air to pass through, a pilot gas pipe that passes through the pilot air pipe and allows pilot gas to pass therethrough, a main gas pipe that passes through the pilot gas pipe and allows the main gas to pass therethrough, and a fireproof body that covers the periphery of the pilot air pipe And
The tip of the pilot gas pipe is closed by the tip of the main gas pipe, and the pilot gas pipe has a pilot gas ejection hole for mixing the pilot gas into the pilot air pipe,
The pilot air pipe is disposed in an insertion hole formed in the fireproof body, and a pilot air passage is formed between an inner peripheral surface of the insertion hole and an outer peripheral surface of the pilot air pipe,
The pilot air pipe has a pilot air ejection hole for ejecting a portion of the pilot air that passes through the pilot air pipe into the pilot air passage.
From the tip of the pilot air pipe, an air-fuel mixture formed by mixing the pilot gas into the pilot air in the pilot air pipe is ejected, and a pilot flame that starts to form by combustion of the air-fuel mixture is injected into the pilot air. A gas burner characterized in that it is configured to supply the pilot air that is ejected from the tip of the passage.   In Claim 1, the flow rate of the pilot air ejected from the front end portion of the pilot air pipe is larger than the flow rate of the pilot air ejected from the front end portion of the pilot air passage, and is ejected from the pilot gas ejection hole. A gas burner characterized in that the air ratio is set to a flow rate of 0.6 to 1.4 with respect to the flow rate of the pilot gas. In Claim 1 or 2, the front-end | tip part of the said pilot gas pipe is formed with the flange part protruded radially outward in the said pilot air pipe, and this flange part is for ejecting the said air-fuel mixture A plurality of gas mixture ejection grooves are formed in the circumferential direction,
A gas burner configured to start the formation of the pilot flame from the vicinity of the downstream side of the formation position of the mixture gas ejection groove.   4. The main fire passage according to claim 1, wherein a main air passage through which combustion air is ejected is formed in the refractory body, and the main gas to be ejected from a tip end portion of the main gas pipe is supplied to the pilot flame. A gas burner configured to be ignited by the combustion air and combusted together with the combustion air ejected from the front end portion of the main air passage.

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