WO1982004303A1

WO1982004303A1 - Combustion device for suppressing exhaust of nitrogen oxide and preventing incomplete combustion

Info

Publication number: WO1982004303A1
Application number: PCT/JP1982/000202
Authority: WO
Inventors: Electric Industrial Co Ltd Matsushita
Original assignee: Kinpara Nobuyuki; Moriya Yoshifumi; Ohashi Tokuyoshi; Hara Masaichi; Ishikura Naoki
Priority date: 1981-05-27
Filing date: 1982-05-27
Publication date: 1982-12-09
Also published as: AU550281B2; GB2111181A; AU8459782A; GB2111181B; GB8301979D0

Abstract

Combustion device which has a premixture surface combustion burner (2) in a sealed structure provided in a combustion chamber (10) preventing secondary air from flowing to the combustion surface to suppress the production of NO2? due to the oxidation of NO in combustion, a catalyst (11) of a transition metal series provided in the rear exhaust gas passage of the combustion chamber (10) to reduce the quantity of NO2? by reducing the NO2? in the exhaust gas into NO, and an oxygen density sensor (22) provided in the combustion chamber (10) of the sealed structure preventing secondary air from flowing thereinto, thereby stopping the combustion by accurately detecting an incomplete combustion state.

Description

Title: Combustion device for controlling emission of nitrogen oxides and preventing incomplete combustion

5 The present invention relates to a combustion device such as a so-called indoor open-type combustor that uses indoor air for combustion and discharges exhaust gas into a room], while improving combustion safety and reducing exhaust gas. It is to clean the

Background art

ブン The conventional burner for household combustion appliances had the drawback of high 窒素 (nitrogen oxide) value because a Bunsen burner was used. Therefore, for equipment that is used for a long time, such as a heating equipment, a mixing burner such as a shuffle burner is used to reduce the temperature. .5 However, because the heat capacity of the ceramic plate, which forms the flame opening, is large in the Shewknowner, it takes a long time to reach stable combustion during spot ignition, This has the disadvantage of adversely affecting air conditioning, and many open-air warm air heaters use a Bunsen burner.

A wire mesh burner shown in FIG. 2 can be considered as a means for compensating for the drawbacks of the above-mentioned Sheubunk burner and further reducing the temperature. In the wire mesh nozzle 23, the fuel jetted from the gas nozzle 24 and the primary air sucked by the effect of the gas are mixed, and as a premixed gas, it passes through the gas mixture chamber 25 to the wire mesh. Surface combustion is performed at the flame outlet 26. In order to keep the temperature of the wire mesh 5 flame outlet 2 6 at a high temperature and maintain stable combustion, An outer metal rod 2 is provided inside the wire mesh opening 26, and the outer periphery of the wire mesh burner 23 is provided so as to effectively take radiant heat from the red-hot wire mesh opening 26 to the outer periphery. It is composed of 28 glass tubes. The wire mesh burner 23 has a smaller heat capacity at the flame opening compared to the Siban Knokna, so that the load can be reduced. It is possible to achieve low and low temperature. 29 is a combustion chamber, 30 is an auxiliary air port to compensate for primary air shortage when the primary air port is clogged, and 31 is a spark plug. However, the influence of the air flow with a large ratio occupied NO ² wire mesh burner also affect the push from server down Kuba Ichina like the human body to perform the surface combustion on NOx, the inflow of air into the combustion chamber If the combustion load is too high, the temperature of the wire mesh is too high to cause backfire, and if the combustion load is too low, the generation of G0 increases. However, there is a disadvantage that it is difficult to change the combustion amount.

Furthermore, to enhance the stability of the premixed surface combustion compensate for air when ^{the primary} air inlet is packed primary air amount is decreased combustion, had led to secondary air to the combustion surface, the secondary air There is a difference between the point at which combustion deteriorates and the oxygen concentration in the combustion exhaust gas detected by the oxygen concentration sensor.9) It is difficult to reliably detect the point at which combustion deteriorates. Had disadvantages.

Disclosure of the invention

The present invention relates to a combustion device such as an open-air type hot-air heater, which aims to reduce NOx and also to reduce N02, which has a large adverse effect on the human body. Et al is a decrease in atmospheric oxygen concentration by poor ventilation, as well as ^primary air inlet packed]? In addition, a combustion device such as a hot-air heater with a highly safe function that can reliably detect an incomplete combustion state due to a blocked hot air outlet and control combustion before the indoor air is contaminated. 5 to provide.

Furthermore, it enables low-load combustion by premixed surface combustion, and makes it possible to vary the amount of combustion as a combustion device such as a warm air heater.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a side sectional view of a combustion device such as a hot-air heater in one embodiment of the present invention, and FIG. 2 is a sectional view showing a conventional burner.

Best mode for carrying out the invention

FIG. 1 is a side sectional view showing the principle of a hot air heater using the combustion device of the present invention.

In the figure, 1 is a casing for a hot-air heater, ² is a burner j, a primary air port 4 provided opposite a gas nozzle 3, a mixing pipe 5, a mixed-air chamber ⁶ , and a combustion cylinder. It is composed of a flame port 8 composed of a wire mesh inside, an outer cylinder ⁹ of a combustion cylinder formed of a metal plate, and a combustion chamber ¹ O having a closed structure for preventing inflow of secondary air. . Combustion chamber

In the exhaust gas passage downstream of 1 o, a transition metal-based catalyst body ¹¹ composed of a glass net, a wire net, etc. is provided.

The air sucked from the suction port 13 by the blower 12 sucks the combustion gas by the guide plate 14 and passes through the air passage ¹⁵ through the temperature 5 around the outer periphery of the combustion cylinder. It is blown from the air outlet ¹ 6. 1 is the first gas ^, 18 is the governor, 19 is the second gas valve, which is ignited from the spark plug 21 by the control circuit 20.

It detects the output of the combustion detection element 22 from a transition metal oxygen concentration sensor such as 102, Sn02, etc., and controls the combustion. _{C In the} above configuration, the gas ejected from the gas nozzle ³ The air required for combustion is sucked from the primary air port 4 as primary air through the primary air port 4, and is guided into the air-fuel mixture chamber 6 while being mixed by the mixing pipe 5. The air-fuel mixture is injected into the combustion chamber 1 O from the flame port 8 composed of a wire mesh, and at the same time, discharges and ignites with the spark plug 21, and performs surface combustion in the flame port 8. Since the flame opening 8 is formed of a wire mesh, its heat capacity is small, and the outer cylinder 9 of the combustion cylinder 9 is made of a metal plate with little radiant heat, so that the flame maintains good combustion even at low load combustion. Mouth temperature is maintained. High. During load combustion, the outer circumference of the outer cylinder ¹ O of the combustion cylinder 7 is a mixed air passage “! 5”, so even if radiant heat is captured, it is cooled and the flame outlet S becomes abnormally hot. No backfire will occur.

In addition, a transition metal-based metal mesh such as stainless steel, molybdenum steel, iron-chromium steel, or a metal mesh in the exhaust gas passage downstream of the combustion chamber 1 o Since the medium 11 is provided in a high-temperature atmosphere of about 5 OO ° (up to OO), the catalyst 11 is reduced to NO 2 in the reduction catalyst and the exhaust gas to NO.

The catalyst body 11 prevents the air flow in the combustion chamber 1 O from being disturbed by the blower blower 12, and prevents the increase in the generation of G 0 gas, which is a problem particularly at low load combustion. .

The combustion chamber 1 O has a closed structure that does not allow air to flow in.

, OMPI To prevent the influence of the air flow in the combustion chamber 1 in 0 by the blower ¹ 2, with and prevents deterioration of the combustibility, since no auxiliary air from entering the bus Ipa scan air, in contact with the catalyst body 1 1 exhaust Since the concentration of O 2 in the gas is reduced, oxidation to N 0 —NO ² is small, and the reduction efficiency is also improved, so that lower NO ² is achieved.

Furthermore, as described above, the combustion chamber 10 has a sealed structure that prevents the inflow of secondary air.], Since the air required for combustion is performed only with premixed air, Since the oxygen concentration in the combustion exhaust gas and the flammability in the combustion chamber have a completely constant relationship, the transitional oxygen concentration sensor, such as Sn02, Ti02, has a low oxygen concentration in the combustion detection element. Primary air clogging. 罈 Wind blowout It is possible to detect deterioration of combustion state due to blockage of air outlet.

As is clear from the above description, according to the 'invention', the combustion chamber is made to be a closed structure, the air flow is small, and the combustion is not affected by the air flow. the NOx accounted NO ² component in the combustion gas can rather small ¾, and the oxygen concentration cell detected accurately incomplete combustion state in the combustion sensing element capacitors', before the indoor air is Okisome will stop burning It is possible to introduce a combustion device such as a hot air heater with high safety to stop the combustion.

Furthermore, by providing a catalyst body in the exhaust gas passage downstream of the combustion chamber, it is possible to prevent turbulence in the air flow in the combustion chamber and achieve low load uniform combustion. ¾] 9 Low NOx and combustion By reducing NO ² in the exhaust gas to N 0, N2 can be further reduced.

In addition, the outer cylinder of the combustion cylinder of the surface combustion burner is made of a metal plate, which is cost-effective compared to conventional glass cylinders. Q

Done.

By providing the catalyst body in the exhaust gas passage downstream of the combustion chamber, and by forming the outer cylinder of the combustion cylinder with a metal plate, it is possible to reduce the load that could not be achieved by conventional surface combustion.] As a combustion device such as a heating appliance, it has become possible to cope with a variable amount of combustion.

Industrial applicability

As described above, according to the present invention, since the premixed surface combustion burner is provided in the closed combustion chamber and the transition metal catalyst is provided downstream of the combustion chamber, NOx, particularly N02, can be reduced. A clean combustion condition is obtained for the human body, and an oxygen concentration sensor is provided in the combustion chamber. J. Incomplete combustion is quickly and reliably detected and combustion is stopped to prevent accidents. Can be.

O PI _

Claims

The scope of the claims

(1) A burner that performs premixed surface combustion is composed of a flame port having a number of small holes such as a wire mesh and a combustion chamber, and the combustion chamber has prevented secondary air from flowing into the combustion surface. A combustion apparatus having a sealed configuration, wherein a transition metal-based catalyst is provided in a combustion gas passage downstream of the combustion chamber.

(≥) The combustion device according to claim ¹ , wherein the inside of the cylindrical combustion cylinder is formed of a wire mesh, and the outer cylinder of the combustion cylinder is formed of a burner formed of a metal plate.

(3) The combustion device according to claim 1, wherein an oxygen concentration sensor is provided in a combustion chamber having a closed structure for preventing inflow of secondary air. -

NAT