JP2001173906A - Catalytic combustion unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve combustibility of a catalytic combustion unit, used as a hand-held heater as a portable small heat source burning gas fuel or liquid fuel, without deteriorating the burning characteristic of steady burning. SOLUTION: A catalytic combustion unit is provided with a gas nozzle 16 jetting fuel gas, a mixing part 20 forming a mixed gas mixing the fuel gas jet from a gas nozzle 16 and air, an air suction tube 18 feeding the air, a variable air flow means 17 changing the air flow path area arranged at the meddle of the air suction tube 18 and a combustion chamber 21, where there are provided catalyst 22 for combustion the mixed gas, where the air flow control means 17 being operated from the outside and the air path area can be changed, before and after ignition.

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 has, for example, a configuration as shown in FIG. Reference numeral 1 denotes a gas tank for storing liquefied petroleum gas such as butane and propane. Fuel gas in the gas tank 1 is ejected from a gas nozzle 4 through a gas flow path 2 and an on-off valve 3. The gas ejected from the gas nozzle 4 is
The air is sucked from the intake port 5 by the effect of the gas flow, mixed with the air in the mixing section 6 and supplied to the combustion chamber 7 as a mixed gas. A catalyst 8 is provided inside the combustion chamber 7, and when the mixed gas passes through the catalyst 8, the mixed gas is combusted by a catalytic action to generate combustion heat.

[0003] Reference numeral 9 denotes an ignition device comprising a piezoelectric element or the like, which is connected to an ignition plug 10 provided on a surface 7b of the combustion chamber 7 opposite to the mixed gas inlet 7a. At startup, the ignition device 9
Is operated to ignite the mixed gas by the sparks blown from the spark plug 10. This ignition forms a flame at the downstream end of the catalyst body 8, and the flame heats the catalyst body 8. When the temperature of the catalyst 8 rises and reaches the activation temperature, catalytic combustion starts on the surface of the catalyst 8. When the catalytic combustion starts, the flame is extinguished because no gas is supplied downstream of the catalytic body 8. And combustion chamber 7
Is burned catalytically by the entire catalytic body 8, and the combustion gas is discharged from the exhaust port 11.

[0004] Such a catalytic combustion device is applied to a portable iron, a heater in clothes, a thermal treatment device, and the like as a portable small heat source.

[0005]

However, such a conventional catalytic combustion apparatus has a problem that the ignition performance at the time of starting is not sufficient.

That is, in the conventional catalytic combustion device, the air-fuel ratio between the gas ejected from the gas nozzle 4 and the air sucked from the intake port 5 is fixed. Then, the ignitability at the time of starting is inferior, and the ignition may occur unless the ignition device 9 is operated many times. In particular, when the outside temperature is low, the gas does not easily ignite, and once ignited, the gas sometimes disappears.

The stoichiometric air-fuel ratio at which the gas is completely burned is assumed to be 1,
When the actual amount of air is represented by the excess air ratio m, it is generally said that the ignitability is most excellent in the range of m = 0.8 to 0.9. However, if steady combustion is performed in this state, unburned gas and carbon monoxide are generated, so that fuel consumption is large and economic efficiency is poor, and it is not preferable for the human body. Therefore, it is usual to perform steady combustion in a range exceeding m = 1.0 (m = 1.1 to 1.2).

In order to solve this problem, for example, an air valve having a thermally responsive body such as a bimetal is provided at the inlet of the intake port 5, and when the temperature of the combustion chamber 7 at the time of starting is low, the amount of air is reduced by the valve. When the temperature rises after the start of combustion, a valve is automatically opened to increase the amount of air. However, since it is necessary to guide heat to the heat responsive body, there are great restrictions on the configuration.
In addition, the air valve with a thermally responsive element has a problem that the amount of air during steady-state combustion is not very stable with a slow-acting type, and it takes time to switch to the amount of air during steady-state combustion with an inverting type. There was also.

[0009]

SUMMARY OF THE INVENTION The present invention relates to an intake pipe for supplying air to a mixing section for mixing a fuel gas and air into a mixed gas, and an air provided in the middle of the intake pipe and having a variable air passage area. A catalytic combustion device is provided which includes an amount variable means, and the air amount variable means is operable from the outside, and also has a variable air passage area at the time of ignition and after ignition.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first 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 and air into a mixed gas, and supplying the air. An intake pipe, an air amount variable means provided in the middle of the intake pipe and varying an air passage area, and a combustion chamber having a catalyst body therein and burning the mixed gas, wherein the air amount variable means is provided. In addition to being operable from the outside, the air passage area is variable at the time of ignition and after ignition,
A catalytic combustion device with improved ignition performance at startup.

According to a second aspect of the present invention, the air amount changing means comprises a movable valve, a valve seat which is opened and closed by the movable valve, and an urging means for urging the movable valve in an opening direction. Sometimes, the area of the air passage is narrowed by a predetermined ratio from when the valve is opened, and the ignitability at the time of starting is improved by operating the movable valve at the time of ignition.

According to a third aspect of the present invention, there is provided a catalytic combustion apparatus in which a throttle hole is provided on the valve seat side, the valve seat is closed by a movable valve when the valve is closed, and an air amount variable means having high operation reliability is provided. And

According to a fourth aspect of the present invention, there is provided a catalytic combustion apparatus having an air amount variable means which is provided with an elastic body on at least one of the contact surfaces of the movable valve and the valve seat and operates reliably even with a small operating force. .

According to a fifth aspect of the present invention, there is provided a catalytic combustion device having excellent operability, wherein an ignition means for igniting the mixed gas is provided, and an air amount variable means is operated in conjunction with the ignition operation of the ignition means. .

According to a sixth aspect of the present invention, there is provided a shut-off valve for shutting off the supply of fuel gas in the event of an abnormality, wherein the air amount variable means is operated in conjunction with the opening operation of opening the shut-off valve. The catalytic combustion device has excellent operability.

[0016]

(Embodiment 1) A first embodiment of the present invention will be described below. FIG. 1 is a sectional view showing the configuration of the catalytic combustion device of the present embodiment. Reference numeral 12 denotes a gas tank for storing liquefied petroleum gas such as butane and propane. The fuel gas in the gas tank 12 is ejected from a gas nozzle 16 of a combustor 15 through an on-off valve 14 through a gas passage 13. Reference numeral 17 denotes an air amount changing means connected to an intake pipe 18 of the combustor 15.

Reference numeral 19 denotes an intake port provided at one end of the air amount variable means 17 for taking in outside air, and communicates with an intake pipe 18 via a valve mechanism described later. 20 is a gas nozzle 16
A mixing unit 21 for mixing the fuel gas ejected from the air and the air sucked from the intake port 19, and 21 is a combustion chamber having a catalyst body 22 therein. Reference numeral 23 denotes an ignition device including a piezoelectric element and the like.
It is connected to a spark plug 24 provided in the combustion chamber 21.
The ignition device 23 and the ignition plug 24 constitute ignition means. An exhaust port 25 discharges the combustion gas to the outside.

FIG. 2 shows the structure of the air amount changing means 17.
Reference numeral 26 denotes a movable valve attached to one end of a sliding shaft 27, which moves in the left-right direction in the figure by sliding the sliding shaft 27 through a hole provided in a valve case. The movable valve 26 moves to the left, contacts the valve seat 29 and closes it to close the valve. An elastic body 30 made of rubber or the like is provided on the valve surface of the movable valve 26 to improve the hermeticity with the valve seat 29 and securely seal with a small operating force.

The movable valve 26 is urged in the opening direction by an urging means 31 composed of a spring.
The valve is in an open state as shown in FIG. 2A, but is in a closed state when the sliding shaft 27 is pushed from outside the valve case 28 as shown in FIG. 2B. On the side surface of the valve seat 29, a throttle hole 32 is provided, which communicates the inlet side (the intake port 19) of the air amount variable means 17 with the outlet 33 side and has an opening area relatively smaller than the opening area of the valve seat 29. ing. Therefore, when the valve is in the open state, the intake air is supplied to the intake port 1 as shown by arrow A.
9 and exits through the outlet 33 through the space between the movable valve 26 and the valve seat 29 as shown by the arrow B. When the valve is closed, the arrow C
As described above, the air exits to the outlet 33 through the throttle hole 32, the area of the air passage is reduced, and the intake air flow rate is reduced by the flow path resistance.

The operation of the catalytic combustion device configured as described above will be described below. When starting the catalytic combustion device, first, the on-off valve 14 is opened to eject the fuel gas from the gas nozzle 16, and at the same time, the sliding shaft 27 of the air amount variable means 17 is pushed to close the valve. Gas nozzle 1
The fuel gas ejected from 6 sucks air from the intake port 19 by the effect of the gas flow, but the intake air flow rate is reduced because the air amount variable means 17 is closed.

In this state, the ignition device 23 is operated to ignite the mixed gas supplied from the mixing section 20 to the combustion chamber 21 by the sparks emitted from the ignition plug 24. At this time, since the intake air flow rate is reduced and the excess air ratio m is suppressed to 1.0 or less, ignition can be easily performed even at a low temperature. If a flame is formed at the downstream end of the catalyst body 22 after ignition, when the sliding shaft 27 of the air amount variable means 17 is released and the valve is opened, the intake air flow rate increases and the excess air ratio m exceeds 1.0, so Steady combustion can be performed without generating gas or carbon monoxide.

FIG. 3 shows the fuel gas flow rate and excess air ratio when the valve is opened and closed when the diameter of the intake port 19 is 6 mm and the diameter of the throttle hole 32 is 1.4 mm (air passage area ratio is about 1/20). It is the graph which measured the relationship with m. It can be seen that even when the flow rate of the fuel gas changes, m = 0.8-0.9 when the valve is closed and m = 1.05-1.2 when the valve is open.

As described above, by providing the air amount varying means 17 capable of varying the air passage area by an external operation and operating it at the time of ignition, it is possible to improve both the ignitability and the exhaust gas characteristics during steady combustion. Become.

Further, since the area of the air passage of the valve mechanism of the air amount changing means 17 is changed by switching the air passage, the area can always be changed at a stable ratio, and the area of the throttle hole 32 provided on the valve seat 29 side can be changed. The area ratio can be easily set only by determining the diameter.

In this embodiment, the air amount varying means 17 is used.
Are arranged right beside the combustion chamber 15, but depending on the device to be installed, there is no need to consider heat transfer or the like simply by extending the intake pipe 18, and it can be arranged at a position that is easy to operate. .

(Embodiment 2) Next, a second embodiment of the present invention will be described. FIG. 4 is a cross-sectional view illustrating the configuration of the catalytic combustion device of the present embodiment. In the figure, the gas tank 12,
Gas flow path 13, open / close valve 14, combustor 15, gas nozzle 1
6. Air volume variable means 17, intake pipe 18, intake port 19, mixing section 20, combustion chamber 21, catalyst body 22, ignition device 23, spark plug 24, exhaust port 25, sliding shaft 27 are the same as those in the first embodiment. It has exactly the same configuration.

In this embodiment, the push button 34 of the ignition device 23 constituting the ignition means is pushed by operating the start button 35, and at the same time, the air is transmitted through the valve link 36 in conjunction with the start button 35. Variable amount means 17
Is pressed. 37 is the combustion chamber 1
5 is a view window made of glass or the like provided on the outer shell of 5 so that the inside of the combustion chamber 21 can be seen from the outside.

With the above configuration, when starting the catalytic combustion device, the on-off valve 14 must be opened before the start button 35
Is pressed, the push button 34 of the ignition device 23 is pressed, and the spark is emitted from the ignition plug 24. At the same time, the sliding shaft 27 of the air amount variable means 17 is pushed by the valve link 36, the valve of the air amount variable means 17 is closed, and the intake air flow rate is reduced. Then, the spark ignites the mixed gas supplied from the mixing section 20 to the combustion chamber 21. At this time, since the intake air flow rate is reduced and the excess air ratio m is suppressed to 1.0 or less, the ignition is easily performed even at a low temperature. can do.

When the ignition button 34 is released when the ignition is confirmed while looking through the viewing window 37, the sliding shaft 27 of the air amount varying means 17 returns to the original position by the urging means 31, so that the valve is opened. As a result, the intake air flow rate increases and the excess air ratio m exceeds 1.0, so that steady combustion can be performed without generating unburned gas or carbon monoxide.

As described above, in this embodiment, the start button 34
By simply operating, the operation of the ignition device 23 and the operation of the air amount variable means 17 can be performed at the same time, and starting can be easily performed,
Since the operation is performed while confirming the ignition through the viewing window 37, it is possible to burn cleanly at m = 1.0 or more immediately after the ignition.

(Embodiment 3) Next, a third embodiment of the present invention will be described with reference to FIG. In the figure, a gas tank 12, a gas passage 13, a combustor 15, a gas nozzle 16,
Air amount variable means 17, intake pipe 18, intake port 19, mixing section 20, combustion chamber 21, catalyst body 22, igniter 23, spark plug 24, exhaust port 25, sliding shaft 27, push button 34,
The start button 35, the valve link 36, and the viewing window 37 have the same configuration as in the second embodiment. The output of the thermoelectric element 40 made of a thermocouple or a thermoelectric power generation semiconductor attached to the combustor 15 instead of the on-off valve 14. A gas shut-off device 41 is provided for detecting the abnormality of the fuel gas and shutting off the supply of the fuel gas.

The gas shutoff device 41 includes an electromagnet 42, a shutoff valve 4
3, a spring 44, a push rod 45, and an electromagnet 4
When power is not supplied to the fuel cell 2, the shutoff valve 43 is pressed by the spring 44 and is in a closed state, so that the fuel gas in the gas tank 12 is not supplied to the gas nozzle 16. When the start button 35 is operated while power is being supplied to the electromagnet 42, the push rod 45 is pushed and the shut-off valve 43 is opened against the urging force of the spring 44, and the open state is maintained by the attraction force of the electromagnet 42. The fuel gas is supplied to the gas nozzle 16.

In this embodiment, power is supplied to the electromagnet 42 by the thermo-electromotive force of the thermoelectric element 40 during normal combustion. However, for example, in the event of an abnormality such as extinguishing during operation or misfiring at start-up, the combustor 15 is activated. Since the temperature drops, the thermoelectric element 40
Cannot supply sufficient electric power to the electromagnet 42, the shut-off valve 43 is closed by the urging force of the spring 44, and the supply of fuel gas is stopped.

In this embodiment, the push rod 45 of the gas shut-off device 41 and the sliding shaft 27 of the air amount variable means 17 are connected by a link 46. By operating a start button 35, the ignition device 23 is operated. The push button 34, the sliding shaft 27 of the air amount variable means 17, and the push rod 45 are simultaneously pressed.

With the above configuration, when the catalytic combustion device is started, when the start button 35 is pressed, the shut-off valve 4
3 is opened and the supply of gas is started, and after a short delay, the sliding shaft 27 of the air amount variable means 17 is pushed by the valve link 36, the valve of the air amount variable means 17 is closed, and the intake air flow is reduced. At the same time, the push button 34 of the ignition device 23
Is pressed, and a spark flies from the spark plug 24. Then, the spark ignites the mixed gas supplied from the mixing section 20 to the combustion chamber 21. At this time, since the intake air flow rate is reduced and the excess air ratio m is suppressed to 1.0 or less, the ignition is easily performed even at a low temperature. can do. Then, if the ignition is performed normally, the temperature of the combustor 15 rises and the shutoff valve 43 is held by the electromotive force of the thermoelectric element 40, and the gas supply is continued.

Accordingly, when the ignition button 34 is released when the ignition is confirmed while looking through the viewing window 37, the sliding shaft 27 of the air amount varying means 17 is returned to its original position by the urging means 31 in a state where gas is supplied. Then, the valve is opened, the intake air flow rate increases, and the excess air ratio m exceeds 1.0, so that steady combustion can be performed without generating unburned gas or carbon monoxide.

As described above, in the catalytic combustion device having the shut-off valve 43 for shutting off the gas supply in the event of an abnormality, the sliding shaft 27 of the air amount variable means 17 is linked to the opening operation of the shut-off valve 43. For example, the operation can be started only by operating the start button 34, and it is not necessary to pay particular attention to the operation of the air amount varying means 17.

In this embodiment, the gas interrupting device 41 is described as a system in which the gas interrupting device 41 is held by the electromotive force of the thermoelectric element 40. It goes without saying that the same effect can be obtained even if it is held.

[0039]

According to the first 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 intake for supplying the air. A pipe, an air amount variable means provided in the middle of the intake pipe and varying an air passage area, and a combustion chamber having a catalyst body therein and burning the mixed gas, wherein the air amount variable means is provided from outside. Operable,
An object of the present invention is to realize a catalytic combustion device in which the air passage area is made variable between ignition and after ignition to improve ignitability at the time of starting.

According to a second aspect of the present invention, the air amount changing means comprises a movable valve, a valve seat opened and closed by the movable valve, and an urging means for urging the movable valve in an opening direction. An object of the present invention is to realize a catalytic combustion device in which the air passage area is sometimes narrowed by a predetermined ratio from when the valve is opened, and the movable valve is operated at the time of ignition, thereby improving the ignitability at the start.

According to a third aspect of the present invention, there is provided a catalytic combustion device having a throttle hole provided on a valve seat side, a valve seat being hermetically closed by a movable valve when the valve is closed, and air amount variable means having high operation reliability. Is realized.

According to a fourth aspect of the present invention, there is provided a catalytic combustion apparatus having an air amount variable means which operates reliably even with a small operating force by providing an elastic body on at least one of the contact surfaces of the movable valve and the valve seat. Is what you do.

According to a fifth aspect of the present invention, an ignition means for igniting the mixed gas is provided, and the air amount varying means is operated in conjunction with the ignition operation of the ignition means, thereby improving operability and improving ignitability at the time of starting. It is to realize an improved catalytic combustion device.

The invention described in claim 6 has a shut-off valve for shutting off the supply of fuel gas in the event of an abnormality, and operates the air amount variable means in conjunction with the opening operation of opening the shut-off valve. It is an object of the present invention to realize a catalytic combustion device having excellent ignitability and improved ignition performance at the time of starting.

[Brief description of the drawings]

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

FIG. 2A is a cross-sectional view of the variable air amount means of the catalytic combustion device. FIG. 2B is a cross-sectional view of the variable air amount means (when the movable valve 26 operates).

FIG. 3 is a characteristic diagram showing a relationship between a gas flow rate and an excess air ratio of the catalytic combustion device.

FIG. 4 is a sectional view of a catalytic combustion device according to a second embodiment of the present invention.

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

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Gas tank 15 Combustor 16 Gas nozzle 17 Air amount variable means 18 Intake pipe 20 Mixing part 21 Combustion chamber 22 Catalyst 23 Ignition device

Continuation of the front page (72) Inventor Hiroshi Uno 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F term (reference) 3K065 TA13 TC05 TD05 TE01 TK02

Claims (6)

[Claims] 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, an intake pipe for supplying the air,
An air amount variable means provided in the middle of the intake pipe and varying an air passage area, and a combustion chamber having a catalyst body therein and burning the mixed gas are provided, so that the air amount variable means can be operated from outside. A catalytic combustion device that makes the air passage area variable at the time of ignition and after ignition. 2. The air amount varying means comprises a movable valve, a valve seat opened and closed by the movable valve, and a biasing means for biasing the movable valve in an opening direction. 2. The catalytic combustion device according to claim 1, wherein the catalyst is throttled by a predetermined ratio. 3. The catalytic combustion device according to claim 2, wherein a throttle hole is provided on the valve seat side, and the valve seat is closed by the movable valve when the valve is closed. 4. The catalytic combustion device according to claim 2, wherein an elastic body is provided on at least one contact surface between the movable valve and the valve seat. 5. The catalytic combustion apparatus according to claim 1, further comprising an ignition unit for igniting the mixed gas, wherein the air amount changing unit is operated in conjunction with the ignition operation of the ignition unit. 6. The catalytic combustion device according to claim 1, further comprising a shut-off valve for shutting off the supply of the fuel gas in the event of an abnormality, and wherein the air amount variable means is operated in conjunction with an opening operation of opening the shut-off valve.