JP6675280B2 - Pilot burner, gas combustion device - Google Patents

Description

  The present invention relates to a pilot burner and a gas combustion device provided with the pilot burner and a main burner.

  When the burner is ignited, usually, the discharge from the igniter electrode is started simultaneously with or before the start of the supply of the combustion gas. This is to prevent explosion ignition that occurs when the mixed gas precedes. Further, in order to obtain reliable ignition, the discharge from the igniter electrode is continued for a certain period of time after the ignition (post-ignition).

  Generally, whether or not the burner ignites normally is confirmed using a flame rod electrode and a flame detection circuit. The frame rod electrode is arranged so that its tip is located in the flame to be detected. The flame detection circuit applies a voltage between the flame rod electrode and the burner, and detects the presence or absence of a flame based on the current detected at that time. The principle is that when there is no flame, there is air between the flame rod electrode and the burner and there is high resistance, but when ignited, there is ions in the flame and the resistance value drops, causing current to flow. Things.

  In the case of a normal burner having a large number of burners, the igniter electrode is provided at one end of the burner, and the frame rod electrode is provided at the other end of the burner to confirm that all the burners have been ignited. Therefore, the discharge from the igniter electrode does not fly to the frame rod electrode.

  In the case of a pilot burner, the flame port is usually small, and the distance between the igniter electrode and the frame rod electrode is short. However, the distance between the igniter electrode and the frame rod electrode is larger than the distance from the igniter electrode to the target electrode (the position where the discharge reaches) of the pilot burner so that the discharge from the igniter electrode does not fly to the frame rod electrode. Set long.

  FIG. 12 shows an arrangement example of the pilot burner 111, the igniter electrode 112, and the frame rod electrode 113. The tip of the igniter electrode 112 is positioned almost directly above the target electrode 114 of the pilot burner 111, and the frame rod electrode 113 is positioned so that the tip is located in the flame generated when the combustion gas is burned by the pilot burner 111. Are located. The distance L2 (eg, 12 mm) from the tip of the igniter electrode 112 to the frame rod electrode 113 is set longer than the distance L1 (eg, 4 mm) from the tip of the igniter electrode 112 to the target electrode 114.

  Even when the pilot burner 111 is ignited, in order to prevent the above explosion ignition and obtain reliable ignition, usually, the combustion gas supply is started (opening the gas cock 117) or the combustion gas supply is started. The igniter drive circuit 115 is first driven to start the discharge from the igniter electrode 112, and after the flame is detected by the flame rod electrode 113 and the flame detection circuit 116, for a while (for example, 5 to 7 seconds). The ignition operation is performed in such a flow that the discharge from the igniter electrode 112 is continued to perform post-ignition. As described above, since L2> L1, discharge from the igniter electrode 112 normally goes to the target electrode 114 of the pilot burner 111 and does not fly to the frame rod electrode 113.

  In addition, in order to prevent explosion ignition from occurring after mis-ignition has occurred many times, Japanese Patent Application Laid-Open No. H11-157210 accumulates the discharge time of unburned raw gas due to mis-ignition. However, there is disclosed a gas combustion device that prohibits an ignition operation until a predetermined ignition prohibition time elapses when the integrated value exceeds a threshold value. Patent Document 2 below discloses a burner unit provided with a rectifying plate having a large number of openings below the flame port so that gas flows uniformly to the flame port.

JP 2011-247540 A JP-A-61-213410

  After the combustion of the pilot burner 111 is stopped, the combustion gas in the gas pipe 118 and the inside of the pilot burner from the gas cock 117 is gradually replaced with air as time passes. Therefore, when the pilot burner 111 is to be ignited after a long time has elapsed since the combustion was stopped, the gas concentration coming out of the flame opening of the pilot burner 111 becomes extremely low for a while after the gas cock 117 is opened, and thereafter, the original gas concentration transiently returns to the original value. It changes to reach the gas concentration.

  As described above, when the pilot burner 11 is ignited, the discharge from the igniter electrode 112 is started at the same time as the gas supply is started or prior to the start of the gas supply. Sometimes. As shown in FIG. 12, the flame generated when the gas concentration is low is in a state in which the root of the flame is lifted from the flame opening of the pilot burner 111 (lifting state).

  In the presence of such a lifted flame, if post-ignition is performed to continue the discharge from the igniter electrode 112 in order to obtain reliable ignition, the part that has risen from the flame outlet will be Therefore, the electrical resistance between the igniter electrode 112 and the target electrode 114 is larger than the electrical resistance between the igniter electrode 112 and the frame rod electrode 113, and the discharge from the igniter electrode 112 It jumps to the electrode 113. As a result, a high voltage is applied to the flame detection circuit 116, which may destroy internal elements, particularly transistors and the like.

  The technique of Patent Document 1 prevents explosion ignition after repeated mis-ignition, and cannot cope with the above problem. In addition, the straightening van disclosed in Patent Document 2 allows the gas to flow uniformly to the flame outlet. Therefore, when lifting occurs, a mixed gas having a low gas concentration is used for the flame burner of the pilot burner 111. It acts to flow uniformly throughout. Therefore, when the ignition is performed in a state where the flame is lifted, the lifting of the flame occurs in the entire pilot burner 111, and the above problem cannot be solved.

  SUMMARY OF THE INVENTION The present invention has been made to solve the above problem, and has as its object to provide a pilot burner and a gas combustion device that can prevent erroneous discharge from an igniter electrode to a frame rod electrode.

  The gist of the present invention to achieve this object lies in the inventions in the following items.

[1] an inlet into which a gas nozzle is inserted, and into which gas and air from the gas nozzle flow;
An outlet in which a plurality of flame outlets are arranged,
A gas passage from the inlet to the outlet,
A target electrode provided near the first flame port of the plurality of flame ports arranged at the outlet portion, and receiving a discharge from the igniter electrode;
Having a flame rod electrode for detecting a flame is a pilot burner installed near a second flame port of the plurality of flame ports arranged in the outlet portion,
A partition wall is provided inside the gas passage so that the gas flowing from the inlet portion makes a detour toward the first flame port, and a passage length from the inlet portion to the first flame port is equal to the entrance portion. To be longer than a predetermined length from the path length to the second flame outlet,
A pilot burner characterized in that:

  In the above invention, a partition wall is provided inside the gas passage so that the gas flowing from the inlet portion makes a circuit and heads toward the first flame port near the target electrode, and the path length from the entrance to the first flame port is provided. Is longer than a passage length from the inlet to the second flame port 6 near the frame rod electrode by a predetermined length or more. Thus, when a thin gas is ignited at the first flame, the dense gas already reaches the second flame, the flame does not lift at the second flame, and an erroneous discharge to the frame rod electrode occurs. Is prevented.

[2] When the gas is sent from the gas nozzle in a state where the inside of the gas passage is entirely in the air state, when the mixed gas having the ignition lower limit gas concentration reaches the first flame port, the gas flowing out of the second flame port The difference between the path length from the inlet to the first flame port and the path length from the inlet to the second flame port is set so that the gas concentration is equal to or higher than the lift lower limit gas concentration. The pilot burner according to [1].

  In the above invention, when the mixed gas having the ignition lower limit gas concentration reaches the first burner port, the gas concentration of the gas exiting from the second burner port is set to be equal to or higher than the lift lower limit gas concentration.

[3] The second flame port is a flame port that is closest to the inlet part among a plurality of flame ports arranged in the outlet part,
The first flame port is a flame port adjacent to the second flame port,
The partition wall partitions the first flame port and the second flame port in the gas passage, and allows the gas flowing from the inlet to reach the first flame port from the side opposite to the second flame port. The pilot burner according to [1] or [2], wherein the pilot burner is formed.

  In the above invention, the first flame port and the second flame port are adjacent to each other, so that the fire can be easily transferred. The length can be significantly longer than the length of the passage to the flame outlet.

[4] Main burner,
A pilot burner according to any one of [1] to [3] for igniting the main burner;
An igniter electrode for igniting the pilot burner;
An igniter drive circuit that generates a discharge by applying a high voltage between the igniter electrode and the target electrode,
A frame rod electrode in which the distance to the igniter electrode is longer than the distance between the igniter electrode and the target electrode and the tip is located in a flame generated in the second flame port;
A flame detection circuit that applies a voltage between the frame rod electrode and the pilot burner, and detects the flame according to a current-carrying state at that time,
A gas combustion device comprising:

  ADVANTAGE OF THE INVENTION According to the pilot burner and gas combustion apparatus which concern on this invention, erroneous discharge from an igniter electrode to a flame rod electrode can be prevented, and damage of a flame detection circuit can be prevented.

It is a figure showing the schematic structure of the gas combustion device concerning an embodiment of the invention. It is a figure showing an example of the igniter drive circuit with which the gas combustion device concerning an embodiment of the invention is provided. It is a figure showing an example of the flame detection circuit with which the gas combustion device concerning an embodiment of the invention is provided. It is a perspective view showing appearance of a pilot burner concerning an embodiment of the invention. FIG. 2 is an exploded perspective view of the pilot burner according to the embodiment of the present invention. It is a figure showing an internal structure of a pilot burner concerning an embodiment of the invention. It is a figure showing the internal structure of the conventional pilot burner. FIG. 7 is a diagram showing a temporal change in the concentration of gas flowing out of a flame outlet of a conventional pilot burner. It is a figure which shows the time change of the gas concentration in the 1st flame mouth and the 2nd flame mouth of the pilot burner which concerns on embodiment of this invention. It is an exploded perspective view of the conventional target electrode and pilot burner. FIG. 4 is an exploded perspective view showing a metal piece that functions as a target electrode and a partition wall in the pilot burner according to the embodiment of the present invention. FIG. 10 is a diagram showing an arrangement relationship of an igniter electrode and a frame rod electrode in a conventional pilot burner. It is a figure showing the state where the flame was lifted.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a view showing a part related to ignition of a pilot burner 11 in a gas combustion device 10 according to an embodiment of the present invention. Here, the gas combustion device 10 is a balanced bath kettle. The gas combustion device 10 includes a main burner (not shown) and a pilot burner (ignition burner) 11 for igniting the main burner. The pilot burner 11 is arranged near the main burner.

  The pilot burner 11 has a plurality (small) of flame ports, and a target electrode 14 is provided so as to protrude upward from a substantially central flame port portion. Above the target electrode 14, the tip of the igniter electrode 12 is arranged. The tip of the igniter electrode 12 has a height located in a flame generated when the combustion gas is burned at a flame outlet immediately below the igniter electrode 12.

  The end of the frame rod electrode 13 is located just above the flame port at one end of the pilot burner 11. The frame rod electrode 13 is also arranged so that the tip is located in a flame generated when the combustion gas is burned at a flame outlet immediately below the frame rod electrode 13.

  The distance L2 from the tip of the igniter electrode 12 to the frame rod electrode 13 is set longer than the distance L1 from the tip of the igniter electrode 12 to the tip of the target electrode 14. For example, L1 is 4 mm and L2 is 12 mm, which is a large difference.

  The igniter drive circuit 15 applies a high voltage (for example, 12 to 15 KV) between the igniter electrode 12 and the target electrode 14 of the pilot burner 11 to generate a discharge from the tip of the igniter electrode 12 to the target electrode 14. Perform the function.

  The flame detection circuit 16 applies a voltage (for example, 100 to 200 V) between the frame rod electrode 13 and the pilot burner 11, and detects the presence or absence of a flame according to the current detected at that time. That is, when there is no flame due to no ignition, there is air between the frame rod electrode 12 and the pilot burner 11 due to high resistance, so that a voltage is applied between the flame rod electrode 13 and the pilot burner 11 by the flame detection circuit 16. However, no current flows during that time. On the other hand, when the flame is ignited, ions are present in the flame, so that the resistance between the frame rod electrode 12 and the pilot burner 11 decreases, and a current flows. The flame detection circuit 16 detects the presence or absence of a flame in the pilot burner 11 (whether or not it is ignited) based on the state of the current when the voltage is applied.

  A combustion gas is supplied to the inlet side of the gas cock 17 from a gas supply source. One end of a gas pipe 18 is connected to the outlet side of the gas cock 17. The other end of the gas pipeline 18 is a gas nozzle 19, which is inserted into a gas inlet (inlet 61, see FIG. 6) of the pilot burner 11. The gas cock 17 switches between supplying and shutting off combustion gas to the pilot burner 11 downstream of the gas cock 17.

  The combustion gas injected from the gas nozzle 19 at the end of the gas pipe 18 and the air (primary air) flowing from around the gas nozzle are mixed while flowing through the gas passage 63 inside the pilot burner 11, and are mixed with the mixed gas. As a result, it flows out of the flame of the pilot burner 11. At this time, the air around the flame outlet (secondary air) is further mixed and burned (see FIG. 6).

  The control circuit 21 controls the driving of the igniter drive circuit 15 and determines the ignition status of the pilot burner 11 from the detection value of the flame detection circuit 16. The power supply of the control circuit 21, the igniter drive circuit 15, and the flame detection circuit 16 is a battery 25 (here, 3 V is supplied). The power supply from the battery 25 to the control circuit 21, the igniter drive circuit 15, and the flame detection circuit 16 is performed only during the operation of the gas combustion device 10, and after the fire is extinguished, the power supply to each part is cut off.

  Two switches 22 that are turned on and off according to the position of the appliance plug knob 24 are connected to the control circuit 21. The two switches 22 determine whether or not the user has turned the appliance plug knob 24 to perform the ignition operation. It is detected by a combination of the on / off state of the switch 22.

  The instrument plug knob 24 can be turned to three positions: "stop", "fire", and "burn". When turning from "stop" to the "fire" position, turn the appliance stopper knob 24 while pushing it in. When turning from the "fire" to "burning" and from the "fire" to the "stop" position, release without pushing. The instrument plug knob 24 is turned in the state in which it is set.

  The operation method for the ignition of the pilot burner 11, the combustion of the main burner, the fire extinguishing, etc. in the gas combustion device 10 is as follows.

  When the instrument plug knob 24 is pressed and turned from the "stop" to the "fire" position, the manual gas cock 17 is opened, the control circuit 21 drives the igniter drive circuit 15, and the pilot burner 11 is ignited. The control circuit 21 determines that the pilot burner 11 has ignited, and turns on the "ignition" lamp. When the user confirms that the lamp is turned on, the pushing of the device stopper 23 is stopped. If the instrument plug knob 24 is set to the “fire” position, the pilot burner 11 maintains the fire. Since the gas cock 17 is manual, it is opened and closed by the user's intention, and the control circuit 21 does not participate in opening and closing.

  When the instrument plug knob 24 is turned from the “fire” to the “burn” position, the combustion gas is supplied to the main burner, and the main burner is ignited from the pilot fire of the pilot burner 11. When the instrument plug knob 24 is returned from the “burning” to the “fire” position, the main burner extinguishes. When the instrument plug knob 24 is turned from the "open flame" to the "stop" position, the gas cock 17 closes and the pilot burner 11 extinguishes.

  In addition, the gas combustion device 10 is a balance-type bath pot or the like installed in a bathroom, and does not include a combustion fan that blows toward a burner like a normal water heater. The balanced bath kettle supplies and exhausts air using a natural draft force generated by heat of combustion. The dedicated air supply / exhaust pipe connected to the balanced bath kettle has the air supply / exhaust ports close to each other, and when wind blows on the air supply side, the same force is applied to the air exhaust ports as well, so that the air supply / exhaust is balanced, Air supply and exhaust are performed with only a small differential pressure of the draft force. That is, the structure is such that combustion is possible without having a blower fan for air supply and exhaust. Since it is installed in the bathroom, the electric power of the dry battery 25 is used instead of using commercial 100 V to prevent electric shock.

  FIG. 2 is a circuit diagram showing details of the igniter drive circuit 15. The igniter drive circuit 15 converts DC 3 V supplied from the battery 25 to AC 100 to 200 V by the converter transformer 31, further boosts the voltage to 12 to 15 KV by the boost transformer 32, and converts the high voltage to the igniter electrode 12 and the pilot burner. 11 is applied. The igniter drive circuit 15 performs a discharging operation when the switch 33 is closed and power is supplied from the battery 25, and stops the discharging operation when the switch 33 is opened and power is supplied from the battery 25. The control circuit 21 controls whether the igniter drive circuit 15 is driven by controlling the opening and closing of the switch 33.

  FIG. 3 is a circuit diagram showing an example of the details of the flame detection circuit 16. The flame detection circuit 16 switches DC3V supplied from the battery 25 by the transistor 41 and boosts the DC3V to 100 to 200V by the transformer 42 and applies it between the flame rod electrode 13 and the pilot burner 11. Further, a current flowing between the frame rod electrode 13 and the pilot burner 11 is detected by the current detection circuit 43, and the detection result is output to the control circuit 21.

  When the igniter driving circuit 15 is driven to discharge from the igniter electrode 12, if the flame is lifted, a phenomenon that the discharge from the igniter electrode 12 flies to the frame rod electrode 13 may occur. The discharge energy that has entered the frame rod electrode 13 is guided from the secondary side of the transformer 42 of the flame detection circuit 16 to the primary side. Since the transistor 41 is connected to the primary side of the transformer 42, the discharge energy that has entered appears as a voltage at the collector of the transistor 41.

  The voltage generated at that time exceeds the absolute maximum rated voltage of the transistor 41 (for example, 50 V). When discharge energy repeatedly enters the flame detection circuit 16 due to discharge from the igniter electrode 12 to the frame rod electrode 13, a voltage exceeding the absolute maximum rating is applied to the collector of the transistor 41 each time, and the deterioration of the transistor 41 proceeds. Eventually, the transistor 41 is damaged, and the flame cannot be detected.

  When the igniter driving circuit 15 is actually discharged in a state where the pilot burner 11 has a flame with a slight lift, the voltage generated at the collector of the transistor 41 of the flame detection circuit 16 is measured. Was. This is twice the absolute maximum rated voltage of 50 V of the transistor 41, and immediately after confirming the voltage, the transistor 41 was damaged.

  Incidentally, whether or not the flame is lifted from the opening of the pilot burner 11 depends on the gas concentration of the mixed gas coming out of the opening.

  For example, when the gas combustion device 10 is installed and first ignited, the portion downstream from the gas cock 17 is all air. Further, when a long time has elapsed since the last combustion stop, the combustion gas inside the pilot burner 11 and the gas line 18 is almost replaced by air. When the gas cock 17 is opened in such a state, the concentration of the mixed gas flowing out of the flame opening of the pilot burner 11 becomes very low for a while, and then the gas concentration transiently increases, and the original combustion that can obtain normal combustion is obtained. Gas concentration is reached. When the igniter electrode 12 is discharged in a state where the gas concentration is low, the flame is lifted at the beginning of ignition, which leads to the damage of the transistor 41 as described above.

  The gas combustion device 10 of the present invention has solved the above-mentioned problem by improving the internal structure of the pilot burner 11. Hereinafter, this point will be described.

  FIG. 4 is a perspective view showing an appearance of the pilot burner 11 according to the embodiment of the present invention. FIG. 5 is an exploded perspective view of the pilot burner 11. FIG. 6 is an explanatory diagram showing the internal structure of the pilot burner 11.

  As shown in FIG. 5, the pilot burner 11 includes two metal plates 51 and 52 in which gas passages and a flame port are recessed by press working so that the inner surfaces of the recesses face each other. The target electrode 14 and a metal piece 53 that functions as a partition wall 64 to be described later are sandwiched and bonded.

  As shown in FIG. 6, the pilot burner 11 has an inlet 61 into which the gas nozzle 19 is inserted, into which gas and air from the gas nozzle 19 flow, an outlet 62 in which a plurality of flame ports are arranged, and an inlet 61. The gas passage 63 reaching the outlet 62, the target electrode 14, and a partition wall 64 that partitions the inside of the gas passage 63 are provided. The target electrode 14 is provided near the first flame port 65 of the plurality of flame ports of the outlet 62. Further, the frame rod electrode 13 is disposed right above the second flame port 66 among the plurality of flame ports of the outlet portion 62.

  The second flame port 66 is a flame port having the shortest passage length to the inlet section 61 among a plurality of flame ports arranged in the outlet section 62. The first flame port 65 is a flame port adjacent to the second flame port 66. The partition wall 64 partitions the first flame port 65 and the second flame port 66 in the gas passage 63, and the gas flowing in from the inlet portion 61 makes a detour, so that the first flame port from the opposite side of the second flame port 66. It is formed so as to reach the mouth 65. Specifically, the partition wall 64 slightly extends downward from the boundary between the second flame port 66 and the first flame port 65, and then bends to the opposite side of the second flame port 66 to be below the first flame port 65. Is a substantially L-shaped member extending so as to surround.

  The partition wall 64 guides the gas such that the gas flowing from the inlet 61 goes round and travels toward the first flame port 65, and the path length from the inlet section 61 to the first flame port 65 (the moving distance of the gas). Increases from the length of the passage from the inlet portion 11 to the second flame port 66 to be longer than a predetermined length. In the pilot burner 11, the path length from the inlet 61 to the second flame port 66 is the shortest L3, and the path length from the inlet 61 to the first flame port 65 is such that the gas detours due to the presence of the partition wall 64. Therefore, it is the longest L4. L4 is longer than the passage length L5 from the inlet 61 to the third flame port 67 which is the farthest in a straight line distance.

  Here, the operation of the partition wall 64 in the pilot burner 11 according to the embodiment of the present invention will be described in comparison with a conventional pilot burner having no partition wall 64.

  FIG. 7 shows an example of a conventional pilot burner 131 having no partition wall 64. The pilot burner 131 is obtained by removing the partition wall 64 from the pilot burner 11 according to the present embodiment, and the other configuration is the same as the pilot burner 11 according to the present embodiment. In FIG. 7, the same portions as those of the pilot burner 11 according to the present embodiment are denoted by the same reference numerals.

  FIG. 8 shows a change in gas concentration at the first flame port 65 when the conventional pilot burner 131 is ignited. The vertical axis represents the gas concentration, and the horizontal axis represents the time after the gas starts flowing from the gas nozzle 19. In the initial state, it is assumed that the entire inside of the pilot burner 131 is filled with air.

  When gas is started to be fed from the gas nozzle 19 into the inlet portion 61, the gas concentration at the first flame port 65 gradually increases with time. At first, since the gas concentration in the first flame port 65 is lower than the lower limit gas concentration of ignition, even if there is a discharge from the igniter electrode 12, the ignition is not performed. This period is defined as a misfire zone.

  Eventually, when the gas concentration at the first flame port 65 exceeds the ignition lower limit gas concentration, ignition occurs. However, since the gas concentration at that time is still low, lifting of the flame occurs. Some time after the ignition, the gas concentration at the first flame port 65 exceeds the lower limit gas concentration of the lift, and the lifting of the flame does not occur. A period in which the gas concentration exceeds the ignition lower limit gas concentration and is lower than the lift lower limit gas concentration is defined as a lift flame zone, and a period after the gas concentration becomes equal to or higher than the lift lower limit gas concentration is defined as a safe flame zone.

  In the conventional pilot burner 131, there is almost no difference between the passage length L3 from the inlet 61 to the second flame port 66 and the passage length L6 from the inlet 61 to the first flame port 65 (see FIG. 7). The change in the gas concentration at the second flame port 66 is substantially the same as the change in the gas concentration at the first flame port 65 shown in FIG. Therefore, when the gas is ignited at the first flame port 65 by receiving the discharge from the igniter electrode 12, the gas is immediately transferred to the gas coming out of the second flame port 66, and the flame of the first flame port 65 and the second flame port 66 are ignited. Flames are lifted together. As a result, discharge from the igniter electrode 12 jumps to the flame rod electrode 13 during post-ignition continued after ignition, and the element of the flame detection circuit 16 (particularly, the transistor 41 in FIG. 3) Will be damaged.

  FIG. 9 shows a change in gas concentration in the pilot burner 11 having the partition wall 64 according to the present embodiment. The vertical axis represents the gas concentration, and the horizontal axis represents the time after the gas starts flowing from the gas nozzle 19. In the initial state, the inside of the pilot burner 11 is assumed to be completely filled with air. The solid line graph in the figure shows the change in gas concentration at the second burner port 66, and the dashed line graph shows the gas concentration change at the first burner port 65.

  In the pilot burner 11 according to the present embodiment, the gas from the inlet portion 61 to the first flame port 65 makes a detour due to the presence of the partition wall 64, so that the ignition timing is delayed as compared with the conventional pilot burner 131. Therefore, when the concentration of gas exiting from the first outlet 65 exceeds the lower limit gas concentration and the gas is ignited at the first outlet 65, the concentration of the gas exiting from the second outlet 66 has already exceeded the lower limit concentration of lift. State. Therefore, when the gas is ignited at the first flame port 65 in response to the discharge from the igniter electrode 12, the flame of the first flame port 65 is lifted. Does not lift. As a result, the discharge from the igniter electrode 12 due to the post-ignition will fly to the metal portion of the pilot burner 11 near the second flame port 66 through the flame, and the situation of flying to the frame rod electrode 13 will be avoided.

  In the pilot burner 11, by providing the partition wall 64, when gas is sent from the gas nozzle 19 in a state where the gas passage 63 of the pilot burner 11 is entirely in the air state, the gas concentration of the gas exiting the first flame port 65 is reduced. At the time when the ignition lower limit gas concentration is reached, the passage length L3 from the inlet portion 61 to the first flame outlet 65 and the inlet portion are set so that the gas concentration of the gas exiting the second flame port 66 is already equal to or higher than the lift lower limit gas concentration. There is a difference from the passage length L4 from 11 to the second flame port 66.

  The partition wall 64 of the pilot burner 11 extends gas from the inlet 61 to the first flame port 65 to extend the length of the passage from the inlet 61 to the first flame port 65. The flow is not rectified by applying resistance to the gas flow so that the gas flow becomes uniform.

  A method for forming the partition wall 64 will be exemplified. In the conventional pilot burner 131, in order to form a target electrode, a metal piece 56 as shown in FIG. 10A is formed by pressing a gas passage or a flame port as shown in FIG. It was sandwiched between the two metal plates 51 and 52 that were recessed.

  Therefore, if the metal piece 56 is replaced with the metal piece 53 shown in FIG. 5, the partition wall 64 can be mounted in the pilot burner 11. FIG. 11 shows a configuration example of the metal piece 53 having the functions of the target electrode 14 and the partition wall 64. A metal strip 53b having the shape of the partition wall 64 is joined to both sides of a base plate 53a in which the lower portion of the conventional metal piece 56 is expanded corresponding to the area where the partition wall 64 is to be formed. 53 is formed. When the metal piece 53 is sandwiched between two metal plates 51 and 52 in which a portion to be a gas passage or a flame port is dented by press working, a portion of the edge piece 53b becomes two metal plates 51 and 52. And a partition wall 64 for partitioning the gas passage 63 by contacting the inside of the gas passage 63.

  If the partition wall 64 is provided by the above method, the pilot burner 11 according to the present embodiment can be manufactured using the same metal plates 51 and 52 as the conventional pilot burner 131, and the gas passage 63 There is no need to newly manufacture a metal plate in which a part to be the partition wall 64 is dented by press working in a part to be a flame outlet, and the cost for improvement can be reduced.

  As described above, according to the pilot burner 11 and the gas combustion device 10 according to the embodiment, by improving the internal structure of the pilot burner 11, the lifting of the flame occurs during the post-ignition, and the discharge from the igniter electrode 12 is reduced. The phenomenon that the flame detection circuit 16 is damaged by flying to the frame rod electrode 13 can be avoided.

  As described above, the embodiments of the present invention have been described with reference to the drawings. However, the specific configuration is not limited to those shown in the embodiments, but may be changed or added without departing from the gist of the present invention. Are also included in the present invention.

  In the embodiment, the gas combustion device 10 has been described as a balanced bath kettle, but is not limited to this. Any gas combustion device having the pilot burner 11 may be used. Further, the shape of the pilot burner 11 and the shape of the partition wall 64 are not limited to those illustrated in the embodiment. For example, a partition wall may be provided such that the gas traveling from the inlet 61 toward the first flame port 65 goes zigzag and goes around.

DESCRIPTION OF SYMBOLS 10 ... Gas combustion apparatus 11 ... Pilot burner 12 ... Igniter electrode 13 ... Flame rod electrode 14 ... Target electrode 15 ... Igniter drive circuit 16 ... Flame detection circuit 17 ... Gas cock 18 ... Gas pipeline 19 ... Gas nozzle 21 ... Control circuit 22 ... Switch Reference numeral 24: Device stopper knob 25: Battery 31 ... Converter transformer 32 ... Step-up transformer 33 ... Switch 41 ... Transistor 42 ... Transformer 43 ... Current detection circuit 53 ... Metal piece 53a ... Base plate 53b ... Edge piece 56 ... Metal piece 61 ... Inlet 62 outlet port 63 gas passage 64 partition wall 65 first flame port 66 second flame port 131 conventional pilot burner

Claims (4)

A gas nozzle is inserted, an inlet portion into which gas and air from the gas nozzle flow,
An outlet in which a plurality of flame outlets are arranged,
A gas passage from the inlet to the outlet,
A target electrode provided near the first flame port of the plurality of flame ports arranged at the outlet portion, and receiving a discharge from the igniter electrode;
Having a flame rod electrode for detecting a flame is a pilot burner installed near a second flame port of the plurality of flame ports arranged in the outlet portion,
A partition wall is provided inside the gas passage so that the gas flowing from the inlet portion makes a detour toward the first flame port, and a passage length from the inlet portion to the first flame port is equal to the entrance portion. To be longer than a predetermined length from the path length to the second flame outlet,
A pilot burner characterized in that: When the gas is fed from the gas nozzle in a state where the entire gas passage is in the air state, when the mixed gas having the ignition lower limit gas concentration reaches the first flame port, the gas concentration of the gas discharged from the second flame port is increased. The difference between the path length from the inlet to the first burner port and the path length from the inlet to the second burner port is set such that is equal to or higher than the lower limit gas concentration. Item 2. A pilot burner according to item 1. The second flame port is a flame port closest to the inlet portion among a plurality of flame ports arranged in the outlet portion,
The first flame port is a flame port adjacent to the second flame port,
The partition wall partitions the first flame port and the second flame port in the gas passage, and allows the gas flowing from the inlet to reach the first flame port from the side opposite to the second flame port. 3. The pilot burner according to claim 1, wherein the pilot burner is formed. Main burner,
A pilot burner according to any one of claims 1 to 3 for igniting the main burner,
An igniter electrode for igniting the pilot burner;
An igniter drive circuit that generates a discharge by applying a high voltage between the igniter electrode and the target electrode,
A frame rod electrode in which the distance to the igniter electrode is longer than the distance between the igniter electrode and the target electrode and the tip is located in a flame generated in the second flame port;
A flame detection circuit that applies a voltage between the frame rod electrode and the pilot burner, and detects the flame according to a current-carrying state at that time,
A gas combustion device comprising: