JPH0674851U - Gas burner pilot gas supply device - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent blowout of the pilot burner due to temporary pressure drop when the main gas supply passage is opened. [Structure] In a pilot gas supply passage 4 branched from a main gas supply passage 3 for supplying a fuel gas to all primary premixed gas burners, a pressure control is provided upstream of a pilot gas control valve 8 in the pilot gas supply passage 4. Gas tank 7
The configuration provided with.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a pilot gas supply device branched from a main gas supply passage for supplying fuel gas to all primary premixed gas burners.

[0002]

[Prior art]

 In recent years, even in heat utilization equipment such as boilers, due to environmental problems such as air pollution, combustion equipment using gas fuel such as city gas and LPG, which have extremely few harmful components in the fuel gas, that is, those using gas burners Is increasing.

In the ignition operation of such a gas burner, the burner is not directly ignited, but a small-capacity pilot burner is ignited once, and the flame of the pilot burner (hereinafter, referred to as pilot flame) is applied to the main burner. It's ignited. Therefore, in addition to the main burner, the pilot burner for ignition as described above is required, and it is also necessary to provide an independent fuel supply path for each burner. Therefore, in order to simplify the structure, there is conventionally known a configuration in which a pilot gas supply passage 24 branched from the main gas supply passage 23 is provided as shown in FIG. The premixed gas burner shown in FIG. 4 is provided with a burner element 22 at one end side of an elongated burner duct 21, and a fuel gas is supplied from a main gas supply passage 23 inserted in the burner duct 21 for combustion which flows in the burner duct 21. A premixed gas is formed together with air, and this premixed gas is ejected from the burner element 22 into the combustion chamber 25, and is ignited and burned by a pilot flame in the vicinity of the burner element 22.

By the way, the premixing type gas burner has a narrow combustion range. For example, in premixing, an air ratio of 2 gives an ignitable concentration, but in premixing, ignition is possible until the state reaches 1.3. Absent. Therefore, if the gas flows out in the same way and the mixture concentration increases in the same way, in the case of premixing, the ignition time until the air ratio 2 becomes 1.3 is delayed compared with premixing, during which the furnace It will be subject to ignition shock, etc. due to the gas flowing out. Therefore, since it is necessary to supply fuel in a short time and ignite, a so-called quick open type main gas control valve 26 is used in the main gas supply passage 23. The main gas control valve 26 is a solenoid valve, a governor (pressure regulator), and a solenoid valve that are integrally incorporated in the same case in that order, and the solenoid valve operates at a high speed. Therefore, when the main gas control valve 26 is opened when the fuel gas is supplied, a phenomenon occurs in which the gas pressure on the upstream side of the main gas control valve instantaneously drops. This is because the gas flow cannot keep up with the speed of pressure propagation, and the pressure is reduced and expanded instantaneously. Due to such a decrease in gas pressure, the amount of gas in the pilot gas supply passage 24, which originally has a small gas flow rate, decreases further at the same time as the pressure decreases, and depending on the piping conditions up to the pilot burner 28, before the main burner is ignited. The pilot flame may be blown out, resulting in misfire. In the figure, 27 is a pilot gas control valve provided in the pilot gas supply passage 24. 28 is a pilot burner.

[0005]

[Problems to be solved by the device]

 It is an object of the present invention to provide a pilot gas supply device that can mitigate the reduced pressure expansion state (gas pressure drop) of the pilot gas supply passage when the main gas control valve of the main gas supply passage is opened. Is.

[0006]

[Means for Solving the Problems]

 That is, this invention is directed to a pilot gas supply passage branched from a main gas supply passage for supplying fuel gas to an all-primary premixed gas burner, in which a pressure control gas tank is provided at a position upstream of the pilot gas control valve in the pilot gas supply passage. Is provided, and the second aspect is characterized in that an orifice mechanism is provided on the upstream side of the pressure adjusting gas tank.

[0007]

[Action]

 According to the present invention, by providing the pressure adjusting gas tank provided in the pilot gas supply passage, it is possible to prevent a temporary gas pressure drop when the main gas control valve in the main gas supply passage is opened. The gas can be supplied to alleviate the reduced pressure expansion state.

[0008]

【Example】

 Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a pilot gas supply device provided in a main gas supply passage 3 for supplying a fuel gas and a pilot gas supply passage 4 branched from the main gas supply passage 3 in a premixed gas burner embodying the present invention. It is explanatory drawing which shows the structure of.

In FIG. 1, reference numeral 1 denotes an elongated burner duct, which blows combustion air from a blower (not shown). Reference numeral 2 denotes a burner element provided on one end side of the burner duct 1, which supplies a fuel gas from the main gas supply passage 3 inserted in the burner duct 1 and preheats it together with combustion air flowing in the burner duct 1. A premixed air-fuel mixture is ejected from the burner element 2 into the combustion chamber 5 for combustion. The main gas supply path 3 is connected to a gas supply source (not shown), and a quick open type main gas control valve 6 is inserted in the middle of the main gas supply path 3 from a predetermined position on the upstream side of the main gas control valve 6. The pilot gas supply path 4 is branched.

As shown in FIG. 1, the pilot gas supply device according to the present invention comprises a pressure control gas tank 7 and a pilot gas control gas from an upstream side of a pilot gas supply path 4 branched from the main gas supply path 3. Each valve 8 is provided, a pilot burner 9 is provided at the tip, and this bilot burner 9 is inserted into the combustion chamber 5 near the burner element 2. The pressure adjusting gas tank 7 is a gas tank having a flow passage cross sectional area larger than that of the pilot gas supply passage 4 and capable of storing a predetermined amount of gas, and functions as a kind of accumulator. Have. The gas tank 7 is used for the pilot gas even if the gas pressure in the main gas supply passage 3 is momentarily lowered when the main gas control valve 6 provided in the main gas supply passage 3 is opened. It is possible to supply the gas stored in the gas tank 7 to the control valve 8 and to damp the pressure propagation from the main gas side.

Next, the experimental data conducted by the embodiment of the present invention will be described. In the first embodiment of FIG. 1, the pilot gas supply passage 4 has a flow passage cross-sectional area of 70 mm. ² (SGP1 / 4B pipe) and the pilot gas input amount from the main gas supply path 3 is 160,000 mm³/ Sec, the pilot gas supply passage 4 has a cross-sectional area of 5120 mm.²(SGP3B) with a capacity of 770,000 mm³ (SGP3B 150 mm) is provided with a pressure adjusting gas tank 7. When the main gas control valve 6 of the main gas supply passage 3 is opened, the gas pressure drop on the inlet side of the pilot gas control valve 8 is As shown in FIG. 3, it was able to be greatly relaxed compared with the case where the conventional gas tank 7 was not provided. That is, 300 mmH without the conventional gas tank₂O → -50mmH₂The pressure dropped to O, but 300mmH when the gas tank of this invention was installed.₂O → 100 mmH₂It becomes O, and the pilot flame is not blown out due to the gas pressure drop compared to the conventional one.

Next, a second embodiment for further blunting the pressure propagation from the main gas supply passage 3 will be described in comparison with the first embodiment. The second embodiment shown in FIG. 2 is provided with an orifice mechanism 10 on the upstream side of the pressure adjusting gas tank 7 shown in the first embodiment of FIG. The orifice mechanism 10 has a Φ4.5 mm orifice (flow passage cross-sectional area 16 mm ² ) that does not affect the pilot gas input amount from the main gas supply passage 3, and has the first portion shown in FIG. As shown in FIG. 3, it is possible to further alleviate the pressure drop of about 20 mmH ₂ O as compared with the case where only the gas tank 7 of the embodiment is taken. The same members as those of the first embodiment other than those described above are designated by the same reference numerals and the description thereof will be omitted.

[0013]

[Effect of device]

 As described above, in the present invention, since the gas tank for adjusting pressure and the orifice mechanism are provided in the pilot gas supply passage of the all-primary premixing type gas burner, the gas when the main gas control valve of the main gas supply passage is opened. The pressure propagation of the pressure drop can be dampened. Therefore, unlike the conventional case, the pilot flame is not blown out before the main burner is ignited due to a temporary gas pressure drop.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a pilot gas supply device for a gas burner showing a first embodiment of the present invention.

FIG. 2 is a schematic explanatory view of a pilot gas supply device of a gas burner showing a second embodiment replacing the first embodiment of FIG.

FIG. 3 is an explanatory view showing a pressure drop state on the pilot gas control valve inlet side of the pilot gas supply passage when the main gas supply passage is opened.

FIG. 4 is an explanatory diagram showing a relationship between a main gas supply passage and a pilot gas supply passage in a conventional gas burner.

[Explanation of symbols]

 3 ... Main gas supply passage 4 ... Pilot gas supply passage 7 ... Pressure adjusting gas tank 8 ... Pilot gas control valve 10 ... Orifice mechanism

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Creator Hideki Karigo 7 Horie-cho, Matsuyama-shi, Ehime Miura Industrial Co., Ltd.

Claims (2)

[Scope of utility model registration request] 1. In a pilot gas supply passage 4 branched from a main gas supply passage 3 for supplying fuel gas to all primary premixed gas burners, a pressure is provided at a position upstream of a pilot gas control valve 8 in the pilot gas supply passage 4. A pilot gas supply device for a gas burner, which is provided with an adjusting gas tank 7. 2. The pilot gas supply device for a gas burner according to claim 1, wherein an orifice mechanism 10 is provided at a position upstream of the pressure adjusting gas tank 7 provided in the pilot gas supply passage 4. Gas supply device.