JP2004271042A - Gas combustion equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the gas ignition performance and the gas combustion performance, and to reduce the concentration of CO. <P>SOLUTION: This combustion equipment 1 comprises a combustor 7 for burning the supplied combustion gas, an ejector 3 having a primary air hole part for sucking the primary air to the combustor 7 by ejector effect, and an ignition device 5 for igniting a mixture gas ejected from a wick 25 mounted in front of the ejector 3. The combustor 7 is composed of a primary combustion chamber 11 for igniting and burning the mixture gas ejected from the wick 25, a secondary air hole part 33 for supplying the secondary air to the burning gas after the ignition in the primary combustion chamber 11, a secondary combustion chamber 13 for further burning the gas burning in the primary combustion chamber 11, and a tertiary air hole part 35 for supplying the tertiary air to the gas burning in the secondary combustion chamber 13. The gas combustion performance can be improved, as the secondary air is supplied to the gas after ignition in the primary combustion chamber 11, even when the amount of primary air is reduced to improve the ignition performance of the mixture gas. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention particularly relates to a gas combustion device that generates completely burned hot air or hot air having high combustion efficiency by using a combustion flame of liquefied petroleum gas (hereinafter, referred to as “LPG”) as a heat source.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a gas combustion device has been used by being incorporated in a device such as a hair dryer or a heat gun using an LPG which is considered to be portable.
[0003]
Referring to FIG. 5 to FIG. 7, for example, in a gas combustion device 101 incorporated in a hair dryer, a combustor 103 for burning gas is provided in a tubular casing 105 of the hair dryer. Burns combustion gas supplied from a gas tank as a gas supply source, and the air heated by the combustor 103 flows out to the outlet side by a blower (not shown) provided at the inlet side of the casing 105. .
[0004]
An ejector 111 having a suction port 109 for sucking outside air due to a negative pressure generated by a flow rate of the combustion gas supplied to the combustor 103 is provided in a gas passage 107 extending from the gas tank to the combustor 103. Is provided. In the ejector 111, for example, the supplied LPG is injected at a high speed from the nozzle 113 in the ejector 111 as shown in FIG. 6, and a negative pressure is generated by the ejector effect due to the injection speed of the gas, so that the combustion is performed. The outside air required for the air is sucked and flows through the suction port 109, so that a mixed gas of gas and air is generated.
[0005]
This mixed gas is ejected from a wick 115 (wire mesh) provided inside the combustor 103 on the inlet side, and sparks are blown from the spark plug 117 (ignition device) to the wick 115 by a high voltage. Ignite mixed gas.
[0006]
The combustor 103 is disposed between the blower and the outlet of the casing 105. The combustor 103 has a wick 115 at the center as shown in FIG. It is a non-circular cylindrical body provided with eight radially grooved combustion chambers 119 in the shape of an eight-segment star-shaped projection around 115 (see Patent Document 1).
[0007]
[Patent Document 1]
JP-A-2002-233416
[0008]
[Problems to be solved by the invention]
By the way, in the conventional gas combustion device 101, since the ejector 111 is provided to supply the combustion gas to the combustor 103, the ejector effect by the injection speed of the gas injected at a higher speed than the nozzle 113 in the ejector 111 is provided. As a result, the outside air is automatically sucked from the suction port 109, so that a mixed gas of gas and air capable of promoting complete combustion is generated and is ejected from the surface of the wick 115.
[0009]
However, the ignition performance of the mixed gas and the combustion performance of the combustion gas after ignition have an opposite relationship. In other words, in order to improve the ignition performance of gas, it is necessary to increase the gas ratio than the air mixture ratio of the mixture gas of air and gas, which originally has good combustion efficiency, but if the combustion is performed in a state where the gas ratio is high, In addition, there is a problem that a large amount of incomplete combustion gas is generated and the combustion performance deteriorates. As a result, the CO concentration increases.
[0010]
Conversely, if the gas ratio is reduced by increasing the amount of air to improve the combustion performance, there is a problem in that when the gas ratio is low, even if the combustion performance is improved, it becomes difficult to ignite and the combustion cannot be performed. Was.
[0011]
Therefore, in practice, in order to maintain a certain degree of ignitability, even if the size of the suction port 109 of the ejector 111 is reduced to reduce the amount of sucked air, the original combustion efficiency is maintained for the reason described above. However, there is a problem that the air mixture ratio is lower than that of the mixed gas having a good air content, so that the air becomes slightly insufficient and the CO concentration becomes high.
[0012]
The inventor has already developed a device for preventing incomplete combustion, and filed an application in Japanese Patent Application No. 2002-249347. The inside of the combustor of this device burns a mixed gas ejected from a wick. It consists of a primary combustion chamber and a secondary combustion chamber that supplies secondary air from the outside air to the gas burned in the primary combustion chamber and burns it, and promotes complete combustion of the combustion gas in the secondary combustion chamber Have been successful in doing so. However, since incomplete combustion occurs slightly in the primary combustion chamber for the above-described reason, there is room for improvement in that the CO concentration is higher than that in the case where the mixed gas having the original high combustion efficiency is burned. Was left.
[0013]
The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a gas combustion device capable of improving the ignitability of a gas, improving the combustion performance of the gas, and reducing the CO concentration. To provide.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, a gas combustion apparatus according to the present invention according to claim 1 includes a combustor for burning a combustion gas supplied from a gas supply source, and a gas passage from the gas supply source to the combustor. An ejector having a primary air hole for sucking primary air due to a negative pressure generated by a flow rate of combustion gas supplied to the combustor, and a mixed gas injected from a wick provided in front of the ejector An ignition device for igniting a gas combustion device,
The combustor has a primary combustion chamber that ignites and burns the mixed gas ejected from the wick, a secondary air hole that supplies secondary air to the gas that burns after the ignition in the primary combustion chamber, and a primary combustion chamber. It is characterized by comprising a secondary combustion chamber for further burning the burned gas, and a tertiary air hole for supplying tertiary air to the gas burning in the secondary combustion chamber.
[0015]
Therefore, even if the ignitability of the mixed gas coming out of the wick is increased by reducing the amount of the primary air, the secondary air is supplied to the ignited gas in the primary combustion chamber, so that the combustion efficiency of the combustion gas in the primary combustion chamber is increased. And combustion performance is improved. Furthermore, in the secondary combustion chamber, tertiary air is introduced from the tertiary air hole, so that the combustion reaction is further promoted, the combustion performance is improved, complete combustion is facilitated, and the CO concentration is reduced.
[0016]
According to a second aspect of the present invention, in the gas combustion apparatus according to the first aspect, the primary air hole portion is provided with a small diameter so as to enhance the ignitability of the mixed gas injected from the wick. It is assumed that.
[0017]
Therefore, by reducing the size of the primary air hole, the amount of primary air is reduced and the gas ratio is increased, so that the ignitability of the mixed gas discharged from the wick is improved.
[0018]
According to a third aspect of the present invention, in the gas combustion apparatus according to the first or second aspect, the secondary air hole is provided at a position where secondary air is supplied to a combustion gas other than an ignition portion. It is characterized by the following.
[0019]
Therefore, in the primary combustion chamber, since the secondary air holes are provided in places other than the ignition section, the amount of air other than the ignition section increases without impairing the ignitability of the ignition section in the primary combustion chamber, and the CO concentration is reduced. Decrease.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0021]
Referring to FIG. 1, a gas combustion apparatus 1 according to the present embodiment includes an ejector 3 for generating a mixed gas by mixing, for example, LPG as a combustion gas and air, and an ejector 3 generated by the ejector 3. For example, an electrode 5 as an ignition device for igniting the mixed gas and a combustor 7 for burning the mixed gas ignited by the electrode 5 are provided.
[0022]
Referring to FIG. 2 to FIG. 4 together, the above-described combustor 7 will be described in more detail. The chamber 9 of the combustor 7 is made of a material of aluminum (die-cat). The left and right side surfaces are substantially circular cylindrical bodies as shown in FIGS. The interior thereof is composed of a primary combustion chamber 11 located on the right side in FIG. 1 and a secondary combustion chamber 13 located in front of this primary combustion chamber 11 (left side in FIG. 1). It is mounted on the gas introduction side behind (to the right in FIG. 1) the combustion chamber 11.
[0023]
In the present embodiment, the ejector 3 is provided with a gas supply source such as a gas tank (not shown) that stores, for example, LPG as a combustion gas at the inlet side of an ejector body 15 having a substantially cylindrical shape. A nozzle 19 for injecting gas supplied through the gas supply pipe 17 is provided. The nozzle 19 has a pinhole injection hole (not shown) having a diameter of, for example, φ60 μm to φ200 μm at its tip, and this injection hole is formed as an orifice provided substantially at the center of a disk-shaped pinhole disk (not shown). Therefore, the LPG is discharged from the injection hole at a high speed at a speed close to the speed of sound. Further, a filter (not shown) for removing impurities and dust for closing the injection hole is built in the nozzle 19. As the filter, for example, a sintered metal having a pinhole having a diameter of 10 to 30 μm is used.
[0024]
Further, a mixer 21 for mixing LPG with primary air and introducing it into the combustor 7 is provided inside the ejector body 15 in front of the nozzle 19, and the primary air is supplied to a side wall of the mixer 21. A primary air hole 23 for suction is penetrated. Therefore, the pressure inside the mixer 21 becomes negative due to the combustion gas discharged from the nozzle 19, and the primary air is sucked and mixed with the combustion gas and sent to the front wick 25, for example, as a gas combustion unit. This is called the ejector effect. The proportion of the primary air can be adjusted by adjusting the area of the primary air hole 23.
[0025]
The wick 25 has a cylindrical shape made of, for example, a 50-150 mesh SUS wire mesh as a gas combustion portion, and is attached to the front end of the ejector body 15 by, for example, welding, and is a primary combustion chamber of the combustor 7. In FIG. 11 of FIG. 1, it is provided substantially at the center on the right side. Further, a wick holder 27 as a rectilinear restraining part is attached to the front end of the wick 25 by, for example, welding. The wick holder 27 suppresses the straight flow of the mixed gas discharged from the mixer 21, mainly promotes the outflow to the side, and discharges the mixed gas of LPG and air from the mesh of the wick 25. The flame after ignition is blue and circular.
[0026]
The above-mentioned electrode 5 is provided inside the combustor 7 at a position close to the front side surface of the wick 25. High voltage electricity generated by a piezoelectric element for ignition (not shown) is input to the electrode 5 through an electric wire 29, and a spark is blown from the tip of the electrode 5 to the wick 25. The spark ignites the mixed gas discharged from the wick 25, and the gas burns.
[0027]
On the inner wall of the primary combustion chamber 11, a plurality of grooves 31 extending in the front-rear direction are arranged radially around the wick 25 as shown in FIG. In FIG. 3, six groove portions 31 are formed.
[0028]
Further, a plurality of secondary air holes 33 for supplying secondary air from the outside to the primary combustion chamber 11 are provided in a rear wall (a right wall in FIG. 1) of the primary combustion chamber 11. The plurality of secondary air holes 33 are arranged so that secondary air is supplied at a position slightly away from the periphery of the wick 25. In other words, the secondary air is arranged so as to be supplied to the post-ignition gas at a position that does not affect the mixed gas immediately after exiting the wick 25, that is, at a position other than the ignition portion. The ignition portion is a range of a portion where a spark flies, and corresponds to the vicinity of the electrode 5 side around the wick 25 as shown by a range surrounded by a dotted line in FIG. In this embodiment, a total of five secondary air holes 33 are provided so that the secondary air is supplied from the rear side of each of the grooves 31 other than the groove 31 in which the electrode 5 is mounted. ing.
[0029]
Further, for example, a plurality of tertiary air pipes 35 as tertiary air holes for supplying tertiary air from the outside air to the secondary combustion chamber 13 are provided in the wall of the primary combustion chamber 11 between the plurality of grooves 31. In this embodiment, a total of six tertiary air conduits 35 are provided.
[0030]
In addition, since the ratio of the primary air can be adjusted by adjusting the area of the primary air hole portion 23 of the ejector 3, in order to improve the ignitability of the mixed gas ejected from the wick 25, this embodiment is performed. In the embodiment, the area of the primary air hole 23 is configured to be approximately half the area of the conventional case. For example, assuming that the diameter of the primary air hole of the ejector in the conventional case is D, the hole diameter of the primary air hole 23 of this embodiment is 0.73D.
[0031]
Furthermore, the hole diameter of each of the five secondary air holes 33 is set to 0.4 D, and the hole diameter of each of the six tertiary air pipes 35 (tertiary air holes) is set to D. ing.
[0032]
A plurality of fins 37 for heat exchange are provided on the outer peripheral side of the chamber 9. The fins 37 have an effect of releasing the heat generated when the mixed gas is burned in the chamber 9 to cool the chamber 9, that is, have an effect of exchanging heat.
[0033]
With the above configuration, when LPG is supplied into the nozzle 19 of the ejector 3 via the gas supply pipe 17, the LPG passes through a filter in the nozzle 19 and is ejected from the injection hole as an orifice to the mixer 21 at a speed close to the speed of sound. Therefore, the primary air (corresponding to the air-fuel ratio) required for combustion is sucked from the primary air hole 23 and flows into the mixer 21 due to the negative pressure generated by the ejector effect in the mixer 21 and flows into the mixer 21. The primary air and LPG are mixed to form a mixed gas, which is ejected to the front wick 25.
[0034]
In the mixer 21, primary air required for combustion is automatically sucked in proportion to the increase or decrease of LPG. However, by reducing the diameter of the primary air hole 23 to reduce the amount of primary air, a mixed gas having good ignitability is injected into the front wick 25.
[0035]
In the wick 25, the wick holder 27 is provided on the front end face, so that the combustion gas (mixed gas) is mainly injected from the SUS wire mesh of the side mesh.
[0036]
Next, high-voltage electricity from the ignition piezoelectric element is supplied via the electric wire 29, sparks are generated from the electrodes 5 in the combustor 7, and the mixed gas having good ignitability that has come out of the wick 25 is reliably ignited. Most of the combustion flame spreads outward from the side surface of the wick 25 in a circular shape, the length of the combustion flame stays at about ten and several mm from the wick 25, and the warm air flows into the inside of the primary combustion chamber 11 and The power is transmitted to the front secondary combustion chamber 13 along the eight grooves 31 of the inner wall.
[0037]
At this time, the mixed gas discharged from the wick 25 has good ignitability due to the high gas ratio, but the CO concentration is increased and the combustion performance is reduced. However, since the secondary air holes 33 are provided in places other than the ignition section, the amount of air in the primary combustion chamber 11 other than the ignition section increases, and the CO concentration decreases. That is, since the secondary air is supplied to the combustion gas after ignition in the primary combustion chamber 11, the combustion efficiency of the gas in the primary combustion chamber 11 is improved, and the combustion performance is improved. Therefore, in the primary combustion chamber 11, the mixed gas from the wick 25 is reliably ignited, and the combustibility of the combustion gas after ignition is promoted, so that the CO concentration is reduced.
[0038]
Further, the tertiary air from the outside air passes through the six tertiary air pipes 35 (tertiary air holes), so that the temperature of the wall of the primary combustion chamber 11 is efficiently reduced and the tertiary air pipes 35 pass through. Then, the tertiary air heated to a high temperature is introduced into the secondary combustion chamber 13, so that the gas in the secondary combustion chamber 13 further promotes the combustion reaction, and the combustion performance is improved. In other words, since the gas that has finished burning in the primary combustion chamber 11 and the high-temperature tertiary air are mixed, the combustion reaction is facilitated, and there is an effect that the complete combustion is facilitated. This improves the combustion performance. As described above, the tertiary air has the effect of lowering the temperature of the primary combustion chamber 11 and the effect of improving the combustion performance in the secondary combustion chamber 13. The number of the tertiary air pipes 35 is desirably eight in order to achieve both combustion performance and heat exchange.
[0039]
As described above, in the gas combustion apparatus 1 according to the embodiment of the present invention, most of the end combustion gas is burned in the secondary combustion chamber 13, so that the flame is hardly generated outside the chamber 9.
[0040]
By the way, an apparatus (comparative example) developed by the present inventor and filed in Japanese Patent Application No. 2002-249347 and a gas combustion apparatus 1 (example of the present application) according to the embodiment of the present invention have the same condition as the CO2 after combustion. When the concentration was measured, in the case of Condition 1, it was 94 ppm in the comparative example, but was 41 ppm in the example of the present application. In the case of the condition 2, it was 119 ppm in the comparative example, but was 49 ppm in the example of the present application. Obviously, in the example of the present application, not only the supply of the tertiary air into the secondary combustion chamber 13 but also the supply of the secondary air into the primary combustion chamber 11 is effective. Note that the above comparative example is an apparatus that supplies tertiary air into the secondary combustion chamber 13 of the combustor 7 corresponding to the example of the present application, but does not supply secondary air into the primary combustion chamber 11. is there.
[0041]
The present invention is not limited to the above-described embodiment, but can be embodied in other modes by making appropriate changes. The gas combustion apparatus 1 according to this embodiment includes a gas dryer such as a hair dryer, a heat gun used for shrinkage work of a heat-shrinkable tube, drying, bonding, melting, soldering, and the like, or gas combustion of other equipment. It can be used as a device.
[0042]
【The invention's effect】
As can be understood from the above description of the embodiment of the invention, according to the invention of claim 1, even if the ignitability of the mixed gas discharged from the wick is increased by reducing the amount of primary air, the primary combustion chamber Thus, secondary air can be supplied to the gas after ignition to improve the combustion efficiency of the combustion gas in the primary combustion chamber, thereby improving the combustion performance. Furthermore, in the secondary combustion chamber, tertiary air is introduced from the tertiary air hole, so that the combustion reaction can be further promoted and the combustion performance can be improved. Therefore, complete combustion can be easily performed, and the CO concentration can be reduced.
[0043]
According to the second aspect of the present invention, by reducing the diameter of the primary air hole, the amount of primary air can be reduced and the gas ratio can be increased, so that the ignitability of the mixed gas discharged from the wick can be improved.
[0044]
According to the third aspect of the present invention, since the secondary air holes are provided in places other than the ignition section in the primary combustion chamber, the amount of air other than the ignition section is increased without impairing the ignitability of the ignition section in the primary combustion chamber. As a result, the combustibility of the gas can be improved, and the CO concentration can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a gas combustion apparatus according to an embodiment of the present invention, which is a cross-sectional view taken along line II of FIG.
FIG. 2 is a side view of the gas combustion device according to the embodiment of the present invention.
FIG. 3 is a front view of the gas combustion device as viewed from the left side of FIG. 2;
FIG. 4 is a rear view of the gas combustion device as viewed from the right side of FIG. 2;
FIG. 5 is a side view of a gas combustion apparatus showing a conventional example.
FIG. 6 is a partial sectional view of the ejector of FIG. 5;
FIG. 7 is a front view of the gas combustion device as viewed from the left side of FIG.
[Explanation of symbols]
1 Gas combustion device 3 Ejector 5 Electrode (ignition device)
7 Combustor 9 Chamber 11 Primary combustion chamber 13 Secondary combustion chamber 15 Ejector body 17 Gas supply pipe (gas flow path)
19 Nozzle 21 Mixer 23 Primary air hole 25 Wick (gas burning part)
27 Wick holder 31 Groove 33 Secondary air hole 35 Tertiary air line (tertiary air hole)

Claims (3)

A combustor for burning the combustion gas supplied from the gas supply source, and a negative pressure generated in the gas flow path from the gas supply source to the combustor due to the flow rate of the combustion gas supplied to the combustor. An ejector having a primary air hole for sucking primary air, and an ignition device for igniting a mixed gas injected from a wick provided in front of the ejector, a gas combustion device comprising:
The combustor has a primary combustion chamber that ignites and burns the mixed gas ejected from the wick, a secondary air hole that supplies secondary air to the gas that burns after the ignition in the primary combustion chamber, and a primary combustion chamber. A gas combustion device, comprising: a secondary combustion chamber for further burning the burned gas; and a tertiary air hole for supplying tertiary air to the gas burning in the secondary combustion chamber. 2. The gas combustion apparatus according to claim 1, wherein the primary air hole is provided with a small diameter so as to enhance the ignitability of the mixed gas injected from the wick. The gas combustion device according to claim 1, wherein the secondary air hole is provided at a position where secondary air is supplied to a combustion gas other than an ignition portion.

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