JPH1073206A - Catalyst combustion apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the glowing starting time in a catalyst combustion apparatus for burning a gas fuel or a liquid fuel. SOLUTION: This apparatus is provided with a gas nozzle 13 to jet out a fuel gas, a mixing part 14 at which the fuel gas jetted out of the gas nozzle is mixed with air to make a mixed gas, a combustion chamber 15 which has a main catalyst body 16 inside to burn the mixed gas and an exhaust port 20 provided on the downstream side of the combustion chamber 15. An auxiliary catalyst body 21 having a metal wire as base body is provided between the main catalyst body 16 and the exhaust port 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalytic combustion device for burning gaseous fuel or liquid fuel.

[0002]

2. Description of the Related Art A conventional catalytic combustion apparatus will be described with reference to FIG. The gas tank 1 stores a liquefied fuel gas such as propane or butane. Fuel gas in the gas tank 1 is ejected from a gas nozzle 3 through a gas flow path 2. The fuel gas ejected from the gas nozzle 3 sucks the surrounding air by the attraction of the gas flow, is uniformly mixed in the mixing chamber 4, and is supplied to the combustion chamber 5. The combustion chamber 5 has a catalyst body 6 inside,
The mixed gas is burned on the surface of the catalyst body 6 to generate combustion heat.

[0003] An ignition device 7 is provided on the opposite side of the air-fuel mixture inlet of the combustion chamber 5, and the mixed gas is ignited by blowing a spark from a plug 8 at the tip of the ignition device 7. The catalyst 6 is heated by the flame formed downstream of the catalyst 6,
When the temperature of the catalyst body 6 reaches the activation temperature, catalytic combustion starts on the surface of the catalyst body 6, the mixed gas is not supplied to the flame, and the flame is extinguished.

[0004] Thereafter, the mixed gas supplied into the combustion chamber 5 performs catalytic combustion on the entire catalyst body 6 in the combustion chamber 5, and the combustion gas is discharged from the exhaust port 9 to the atmosphere.

[0005]

However, such a conventional catalytic combustion apparatus has the following problems.

[0006] In order to completely burn the fuel that has come into contact with the surface of the catalyst, the catalyst temperature must be maintained at a temperature higher than the specific activation temperature in advance. For this reason, a method is employed in which the catalyst is heated by a flame at the time of startup, the catalyst temperature is raised to an activation temperature or higher, and then fuel is supplied to the catalyst to start catalytic combustion.

In practice, however, a time lag occurs when the temperature of the catalyst reaches the activation temperature, the mixed gas is no longer supplied to the flame, and the flame extinguishes, and between when the catalyst starts to burn and the catalyst glows red. There is a problem that the time lag is long in the conventional catalytic combustion device.

Accordingly, an object of the present invention is to provide a catalytic combustion device having a short red heat start time in consideration of the above-mentioned problems of the conventional catalytic combustion device.

[0009]

According to a first aspect of the present invention, there is provided a gas nozzle for ejecting a fuel gas, and a mixture of the fuel gas and the air ejected from the gas nozzle to form a mixed gas. And a combustion chamber having a main catalyst body inside for burning the mixed gas, and an exhaust port provided downstream of the combustion chamber, and a metal wire as a base between the main catalyst body and the exhaust port. A catalytic combustion device comprising an auxiliary catalyst body.

[0010] The main catalyst body wall surface and the auxiliary catalyst body having a metal wire as a base may be thermally connected.

The main catalyst body has a communication hole therein, and a heat conductor is inserted so as to close all or a part of the communication hole of the main catalyst body. A configuration may be employed in which an auxiliary catalyst body having a wire as a base is thermally connected.

Further, there is provided a flame-extinguishing net provided between the exhaust port and the combustion chamber, and an auxiliary catalyst having a metal wire as a base and provided between the main catalyst and the flame-extinguishing net. The configuration may be such that the auxiliary catalyst body is thermally connected. Next, according to a fifth aspect of the present invention, there is provided a gas nozzle for ejecting a fuel gas, a mixing section for mixing the fuel gas ejected from the gas nozzle with air to form a mixed gas, and an interior for burning the mixed gas. A catalytic combustion device comprising a combustion chamber having a medium and an exhaust port provided downstream of the combustion chamber, wherein a downstream portion of the catalyst body has an unsupported layer on which no catalyst is supported.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) A catalytic combustion apparatus according to a first embodiment of the present invention will be described with reference to FIG. The gas tank 11 stores a liquefied fuel gas such as propane or butane. The fuel gas in the gas tank 11 is
Through the gas nozzle 13. Gas tank 11
A gas flow control valve (not shown) may be provided between the gas nozzle 13 and the gas nozzle 13 so that the flow rate of the fuel gas supplied from the gas tank 11 can be controlled. The fuel gas ejected from the gas nozzle 13 sucks the surrounding air by the attraction of the gas flow, is uniformly mixed in the mixing chamber 14, and is supplied to the combustion chamber 15. The combustion chamber 15 has the main catalyst 1 therein.
6, which burns the mixed gas on the surface of the main catalyst 16 to generate combustion heat. As the catalyst supported on the main catalyst body 16, a platinum group metal and a metal oxide such as nickel, cobalt, iron, manganese, and chromium are used, and particularly preferred are platinum group metals such as platinum, palladium, and rhodium.

The fuel gas is supplied from the gas nozzle 13 to the mixing chamber 14.
Then, the air and the fuel gas, which are attracted to the fuel gas ejection power and are sucked, are mixed in the mixing chamber 14, and the mixed gas is supplied to the combustion chamber 15. An ignition device 17 is provided on the opposite side of the air-fuel mixture inlet of the combustion chamber 15.
By blowing the spark from the plug 18 at the tip, the mixed gas is ignited, and the flame 1 adhering to the downstream portion of the main catalyst 16 is
9 is formed.

Further, the combustion heat is transmitted from the base of the flame 19 to the main catalyst 16, and the main catalyst 16 is heated. When the temperature of the main catalyst 16 reaches the activation temperature, catalytic combustion starts from the downstream portion of the main catalyst 16, the mixed gas is not supplied to the flame 19, and the flame 19 is extinguished. Thereafter, the main catalyst body 16
The catalytic combustion spreads toward the upstream part of the
6, the catalytic combustion is performed on the whole, and the main catalyst 16
Glows red. The combustion gas burned in the combustion chamber 15 is discharged from the exhaust port 20 to the atmosphere.

In the conventional catalytic combustion apparatus, the only means for heating the main catalyst 16 at the time of starting is the flame 19 formed downstream of the main catalyst 16. For this reason, it is difficult to say that the main catalyst 16 is sufficiently heated, and the flame 1
There was a case where the time lag from the disappearance of 9 to the main catalyst 16 glowing was long.

However, in the present invention, the auxiliary catalyst 21 is disposed between the main catalyst 16 and the exhaust port 20 provided in the combustion chamber 15.
Is provided. For this reason, the flame 19 formed downstream of the main catalyst 16 heats the main catalyst 16 by supplying heat from the base of the flame 19, as well as the high-temperature combustion gas generated by the flame combustion. Or the auxiliary catalyst body 21 is directly heated by the flame tip. Here, since the auxiliary catalyst 21 is a catalyst based on a metal wire such as an expanded metal, the main catalyst 1
6 has a very small heat capacity.
At the point when the temperature of 6 reaches the activation temperature and the flame formed on the downstream side of the main catalyst 16 disappears, red heat has already started.

Generally, it is known that the radiation efficiency is high in catalytic combustion. Therefore, the catalyst itself has a property of absorbing radiant heat very well. Therefore, the radiant heat radiated from the red-heated auxiliary catalyst body 21 is very well absorbed by the main catalyst body 16, and greatly contributes to the temperature rise of the main catalyst body 16. Conventionally, the temperature rise of the main catalyst body 16 after the flame 19 was extinguished was only the reaction heat due to the catalytic combustion of the main catalyst body itself.
As described above, since the radiant heat from the auxiliary catalyst body 21 is added in addition to the reaction heat due to the catalytic combustion of the main catalyst body itself, the speed of the temperature rise of the main catalyst body 16 is significantly increased, and the flame 19 The time lag from the disappearance to the time when the main catalyst 16 glows red can be shortened.

Further, as shown in FIG. 2, a configuration may be employed in which the wall surface of the main catalyst 16 and the auxiliary catalyst 21 are thermally connected. 2A is a side view, and FIG. 2B is a front view. With this configuration, when the main catalyst 16 is heated, in addition to the radiant heat from the auxiliary catalyst 21, the combustion heat in the auxiliary catalyst 21 is supplied to the main catalyst 16 by direct heat conduction from the auxiliary catalyst 21. As a result, the time lag until further glowing can be reduced.

In FIG. 2, the shape of the auxiliary catalyst body 21 is convex, but the same effect can be obtained by using a cylindrical or flat plate.

As shown in FIG. 3, the main catalyst body 16 has a communication hole therein, and a heat conductor 22 is inserted so as to close a part or all of the communication hole. The configuration may be such that the auxiliary catalyst body 21 and the heat conductor 22 are thermally connected. With such a configuration, the heating by the direct heat conduction from the auxiliary catalyst body 21 is performed not only from the wall surface of the main catalyst body 16 but also from the inside of the main catalyst body 16, so that the time lag until further glowing is reduced. be able to.

When the mixed gas is ignited by the igniter 17, the flame may propagate to the downstream side of the combustion chamber 15.
In order to prevent this, in general, in the catalytic combustor, as shown in FIG. 4, a flame-extinguishing net 23 made of a metal mesh, a panning metal or the like is provided near the exhaust port 20. When the propagated flame passes through the flame-extinguishing net 23, heat is taken away by the flame-extinguishing net 23, so that the flame is extinguished. On the other hand, if a misfire or the like occurs, the catalyst is not heated at the time of start, and catalytic combustion does not start even if the fuel gas is supplied to the catalyst, if a flame such as a lighter is brought close to the exhaust port 20, the exhaust Flame may adhere to the flame-extinguishing net 22 provided near the mouth.

However, in the present embodiment, the main catalyst 16
An auxiliary catalyst 24 having a metal wire as a base is provided between the flame quenching net 23 and the auxiliary catalyzer 24.
And are thermally connected. When the flame 25 adheres to the flame extinguishing net 23, heat is transmitted from the base of the flame 25 to the auxiliary catalyst 24 via the flame extinguishing net 23, the auxiliary catalyst 24 reaches the activation temperature, and the auxiliary catalyst 24 starts catalytic combustion. When the auxiliary catalyst 24 starts catalytic combustion, the mixed gas is not supplied to the flame 25, and the flame 25 is extinguished. On the other hand, radiant heat is radiated from the auxiliary catalyst 24 performing catalytic combustion, and the radiant heat heats the main catalyst 16. For this reason, the temperature of the main catalyst 16 rises, reaches the activation temperature, and the main catalyst 16 starts catalytic combustion. Therefore, by providing the auxiliary catalyst 24, even if a flame adheres to the flame extinguishing net 23, the flame is extinguished, and the effect that the main catalyst 16 can start catalytic combustion normally is added. (Embodiment 2) A catalytic combustion apparatus according to a second embodiment of the present invention will be described with reference to FIG. The gas tank 31 stores a liquefied fuel gas such as propane or butane. The fuel gas in the gas tank 31 is
Through the gas nozzle 33. Gas tank 31
A gas flow control valve (not shown) may be provided between the gas tank 33 and the gas nozzle 33 so that the flow rate of the fuel gas supplied from the gas tank 31 can be controlled. The fuel gas ejected from the gas nozzle 33 sucks the surrounding air by the attraction of the gas flow, is uniformly mixed in the mixing chamber 34, and is supplied to the combustion chamber 35. The combustion chamber 35 contains the main catalyst 3
6 to burn the mixed gas on the surface of the main catalyst body 36 to generate combustion heat. As the catalyst supported on the main catalyst body 36, a platinum group metal and a metal oxide such as nickel, cobalt, iron, manganese and chromium are used, and particularly preferred are platinum group metals such as platinum, palladium and rhodium.

The fuel gas is supplied from the gas nozzle 33 to the mixing chamber 34.
The fuel gas is supplied to the fuel chamber, and the air and the fuel gas, which are attracted to the jet power of the fuel gas, are mixed in the mixing chamber 34, and the mixed gas is supplied to the combustion chamber 35. An ignition device 37 is provided on the opposite side of the air-fuel mixture inlet of the combustion chamber 35, and by blowing a spark from a plug 38 at the tip of the ignition device 37, the mixed gas is ignited and the flame attached to the downstream portion of the main catalyst body 36 39 are formed. Combustion heat is supplied to the main catalyst body 36 from the base of the flame 39, and the main catalyst body 16 is heated. When the temperature of the main catalyst body 36 reaches the activation temperature, catalytic combustion starts from the downstream portion of the main catalyst body 36, the mixed gas is not supplied to the flame 39, and the flame 39 is extinguished. Thereafter, the catalytic combustion spreads toward the upstream portion of the main catalyst body 36, and the entire main catalyst body 36 begins to perform catalytic combustion, and the main catalyst body 36 glows red. The combustion gas burned in the combustion chamber 35 is discharged from the exhaust port 40 to the atmosphere.

In the conventional catalytic combustion device, the main catalyst 36 is heated by the flame 39 formed at the downstream of the main catalyst 36 at the time of starting. On the other hand, the stability of the flame is affected by the state in which the flame base adheres to the flame opening. Therefore,
When the catalytic combustion starts at the flame base and the mixed gas is not supplied to the flame base stably, the flame 39 formed downstream of the main catalyst body 36 rises from the main catalyst body at the flame base.
The flame 39 is extinguished. For this reason, it is difficult to say that the main catalyst 36 is sufficiently heated, and the time lag from when the flame 39 is extinguished to when the main catalyst 36 glows red may be long.

However, in the present invention, an unsupported layer 41 on which no catalyst is supported is provided downstream of the main catalyst body 36. With such a configuration, the flame 39 formed at the downstream portion of the main catalyst body 36 at the time of start-up does not carry a catalyst at the flame base portion. The stability of the flame 39 formed in the downstream portion is improved, and the time until the flame extinguishes becomes longer. Therefore, the main catalyst 36 is sufficiently heated, and the time lag from when the flame 39 is extinguished until when the main catalyst 36 glows red can be reduced.

[0027]

As is apparent from the above description,
According to the present invention, it is possible to provide a catalytic combustion device having a short red heat start time.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a catalytic combustion device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a catalyst body according to the first embodiment of the present invention.

FIG. 3 is a configuration diagram of another example of the catalyst body according to the first embodiment of the present invention.

FIG. 4 is a vertical sectional view of another example of the catalytic combustion device according to the first embodiment of the present invention.

FIG. 5 is a vertical sectional view of a catalytic combustion device according to a second embodiment of the present invention.

FIG. 6 is a vertical sectional view of a conventional catalytic combustion device.

[Explanation of symbols]

 13, 33 Gas nozzle 14, 34 Mixing chamber 15, 35 Combustion chamber 16, 36 Main catalyst 20, 40 Exhaust port 21, 24 Auxiliary catalyst 22 Heat conductor 23 Flame extinguishing net 41 Unsupported layer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Motohiro Suzuki 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] A gas nozzle for jetting a fuel gas, a mixing section for mixing the fuel gas jetted from the gas nozzle with air to form a mixed gas, and burning the mixed gas;
An auxiliary catalyst body having a metal wire as a base is provided between the main catalyst body and the exhaust port, comprising a combustion chamber having a main catalyst body therein and an exhaust port provided downstream of the combustion chamber. A catalytic combustion device. 2. The catalytic combustion apparatus according to claim 1, wherein a wall surface of the main catalyst body and an auxiliary catalyst body having the metal wire as a base are thermally connected. 3. The main catalyst body has a communication hole inside, and a heat conductor is inserted so as to close all or a part of the communication hole of the main catalyst body, and a wall surface of the main catalyst body and the heat 3. The catalytic combustion device according to claim 1, wherein the conductor and the auxiliary catalyst having the metal wire as a base are thermally connected. 4. A flame-extinguishing net is provided between an exhaust port and a combustion chamber, and the auxiliary catalyst is provided between the main catalyst and the flame-extinguishing net. And 2 are thermally connected.
Or the catalytic combustion device according to 3. 5. A gas nozzle for ejecting a fuel gas, a mixing section for mixing the fuel gas ejected from the gas nozzle with air to form a mixed gas, and burning the mixed gas,
A catalyst comprising: a combustion chamber having a catalyst therein; and an exhaust port provided downstream of the combustion chamber, wherein a downstream portion of the catalyst has an unsupported layer on which no catalyst is supported. Combustion equipment.