JPS6057112A - Combustion device - Google Patents

Abstract

PURPOSE:To perform stable combustion without deteriorating low NOX production properties and to improve the throttle efficiency of a combustion amount, by a method wherein a primary burner port is formed with a wire net and a punching plate or a ceramic plate having pores. CONSTITUTION:Primary combustion chambers 9 are formed in a casing 10 which rises from ends of primary burner ports 6 and 7 to the combustion exhaust gas downstream side, and are inclined inwardly from a proper position, and secondary burner ports 11 are formed at the ends of slanted surface. Where an equivalence ratio phi is less than 1, a total primary surface combustion flame, in which a flame is formed only on the primary burner ports 6 and 7, is formed, and the flame surface is protected by the primary combustion chambers 9. Thereby, a secondary air is prevented from flowing in, a uniform and low temperature flame is formed, and NOX is prevented from production. A secondary air is prevented from flowing in TDR, and a flame surface is inhibited against cooling. Various combustion of combustion amount ratios of a large burner 4 and a small burner 5 enables arbitrary TDR to be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an all-primary surface combustion burner whose primary flame holes are wire mesh, punched plates or ceramic plates.

Conventional configurations and their problems In recent years, gas and oil fan heaters have been increasingly used as home heating appliances due to their economical efficiency, rapid heating, and ease of use.

Since these fan heaters release the combustion exhaust gas 21' varnish into the room, the cleanliness of the combustion exhaust gas is one of the important issues imposed on the fan heaters. Based on this background, the hot air heating device disclosed in Japanese Patent Application Laid-Open No. 57-198946 exhibits extremely excellent characteristics in terms of cleanliness, and generates extremely little nitrogen oxides (hereinafter referred to as NOx). However, in such a hot air heating device, if the equivalence ratio is set close to 1 or 1 or more for some reason, the above-mentioned cleanliness deteriorates. We will explain this using Figure 1.

A primary flame hole 2 is formed with a wire mesh inside a cylindrical combustion tube 1, and a pressure equalizing plate 3 made of a lath mesh is provided on the downstream side of the combustion exhaust gas. In the normal combustion state (equivalence ratio z<1), this burner has
Extremely low NOx to form a uniform, low temperature surface combustion flame. However, if the equivalence ratio y≧1 occurs due to damper blockage, oxygen deficiency, etc., the flame will expand and touch the pressure equalizing plate 3, which will cool the flame and partially freeze the oxidation reaction, resulting in abnormal CO production. There was a problem of producing

From the economical point of view of heating equipment, it is better to have better combustion rate restriction performance (hereinafter referred to as 'rl)l (hereinafter referred to as 'rl). , TDR = 1/2 is the limit, and the economic efficiency is also sufficient (!: There is not much that can be said. ' The invention's ``1 misfire F! It is an object of the present invention to provide a burner that performs stable combustion by substituting diffusion combustion from primary combustion without impairing the low NOx properties of a primary surface combustion burner, and has excellent control over the amount of combustion. do.

Configuration of Ignition 1 In order to achieve this purpose, the unexploded IJI has a plurality of surface combustion burners arranged in parallel, each of which has a primary flame hole made of a wire mesh, a punched plate, or a ceramic plate with small holes.
The primary flame hole group constituted by the plurality of flame holes arranged side by side is isolated by a partition plate that stands from below each flame hole, and forms a secondary combustion chamber and a secondary flame. It is surrounded by a casing having holes.

According to this configuration, when the equivalence ratio O < 1, the flame is an all-primary surface combustion flame that is formed only by the flame or the primary flame hole group, and since the flame front is protected by the primary combustion chamber, There is no inflow of air, and the temperature is uniform and low (900-1200K)
flame, and the generation of NOx is suppressed. It's small, T.
DRu: Since there is no inflow of secondary air, the flame front is not cooled and becomes good. Furthermore, in order to increase the TDR, the required TDR can be secured by controlling the fuel supply of multiple surface combustion burners, and since each flame hole is separated by a partition plate, it is possible to secure the required TDR. Even if a burner is not firing and secondary air flows out through the mixing tube of the burner and from the flame hole, this secondary air will cool the flame surface of the burning burner. It can maintain a stable flame without saying a word. Next, considering the case where the current J■ ratio/≧1, in the configuration of the present invention, unburnt gas and intermediate products form a stable diffusion flame on the secondary flame hole through contact with the secondary air. Therefore, even under such combustion conditions, low NOx combustion can be achieved.

5''' In this way, not only can stable combustion be achieved in the diffusion combustion range from the primary combustion, but also low N O can be achieved throughout the entire combustion range.
x combustion can be achieved.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 2 and 3. There are two different types of combustion, Mugimenen and Akatsuki Burner, and a large combustion burner (hereinafter referred to as large burner).

) 4 and a burner with a small combustion amount (hereinafter referred to as a small burner).

) consists of 5 large burner 4 primary flame hole 6 and small burner 5
The primary flame hole 7 is -1 convex on one side, and is in pressure contact with a downwardly convex mixing tube 8 located below. -The next combustion chamber 9 is -
The secondary flame hole 1 is constructed inside the casing 10 which is formed by standing up from the end of the flame hole 6.7 on the downstream side of the combustion exhaust gas and tilting inward from an appropriate position.
1 is formed at the end of the inclined surface of the housing 10 described in iii. The partition plate 12 is connected at one end to the point where the ends of the flame holes 6 and 7 join, and at the other end is connected to the upper secondary flame hole 11.
It stands at the same height as the sword. The uncircumcised flame detection elements (here, a frame 6.'rond is used) 13a, 13b, and 13c are mounted on one side of the flame hole 6.7 and the secondary flame hole 11, respectively.
It is placed on one side.

According to the above configuration, when the equivalence ratio is <1, one flame is a primary surface combustion flame formed only in the primary flame hole 6.7''2, and the flame surface is protected by the primary combustion chamber 9. There is no inflow of secondary air, and the temperature is uniform and low (900-1200
K), and the generation of NOx is suppressed. Also,
TDR is good because there is no inflow of secondary air, so the flame front is not cooled. By combining various combustion ratios of the large burner 4 and the small burner 5, any TDR can be obtained. Specifically, if the flame hole loads are set so that the ratio of the combustion amount of the large burner and the small burner 5 is 5=1, the maximum combustion (large burner 4 and small burner 5
Both burn. ) It can be set to 6:1 compared to the minimum combustion (only the small burner 5 burns). Moreover, in this case, since each flame hole 6.7 is isolated by the partition plate 12, the adjacent burner is not burning, and the mixing tube of the same burner is separated by 7'°.
- Even if secondary air flows out from the flame hole, the flame surface of the burning burner is not cooled by this secondary air, and a stable flame can be maintained.

- Ion current value characteristics of Buba flame detection elements 13a, 13b, 13c, -Flame hole'' flame detection elements 13a, 1
The ion current value of 3b is always larger than the ion current value of flame detection element 13c of secondary flame hole -1-. Next, considering the case where the equivalence ratio y≧1, the burnout cannot be completed with a flame hole of 6.7''. Unburned, gas j.・In order to form a stable diffusion flame on the secondary flame hole by contact with the secondary air, the yonakamon product forms a stable diffusion flame on the secondary flame hole, so under conditions such that the equivalence ratio y≧1, This corresponds to missing/damper blockage, but
Even under such conditions, stable low NOx combustion can be achieved. In this way, from the total combustion of MsJt〆1,
Not only can stable combustion be performed up to the premix and diffusion combustion ranges where JtS≧1, but also low N throughout the entire combustion and boundary ranges.
Ox combustion can be achieved. Although the ion current value characteristics are related to -, under the condition of equivalence ratio G≧1, the ion current value of 1 flame detection element 13c - 1 flame detection element 13a, 1
The ion current value is almost different from or larger than that of 3b, which means that the ion current value characteristics are opposite to those under the condition of equivalence ratio 96<A. That is, due to the equivalence ratio /, the flame detection element 13a on the second flame hole.

By utilizing the phenomenon in which the ion current value of the secondary flame hole 13b and the ion current value of the flame detection element 13c of the second flame hole are reversed, oxygen deficiency detection and Gumpa blockage detection can be performed.

Effects of the invention (1) Stable combustion with suppressed NOx and Co generation can be performed over a very wide range from full-secondary combustion to diffusion combustion and waste acid 1.

(2) TDR can be set to any value.

(3) Even under conditions of low 02 concentration, combustion is performed on the secondary flame hole using secondary air, so combustion can be performed while suppressing the generation of CO.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a conventional low NOx burner, Fig. 2 is a front view of a part of a combustion device according to an embodiment of the present invention, cut away on page 9, and Fig. 3 is a cross-sectional view of a conventional low NOx burner. - It is a sectional view taken along the A line. 6.7...Primary flame hole, 9...Primary combustion chamber, 10...Casing, 11...Secondary flame hole, 12. ...Partition board. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure

Claims (1)

[Claims] A plurality of surface combustion burners constituting a primary flame hole are arranged in parallel using a wire mesh, a punched plate, or a ceramic plate having small holes, and a primary flame hole group constituted by the plurality of surface combustion burners is arranged in parallel with each other. A combustion device that is isolated from below by a partition plate raised in one direction, forms a secondary combustion chamber, and is surrounded by a casing having a secondary flame hole.