JPH02219901A - Burning device - Google Patents

Abstract

PURPOSE:To reduce the production of NOx to improve cleanness and safety by winding opening parts of both side faces of a burner port hole to enlarge the spread of a flame. CONSTITUTION:A primary burner port 4a extends a slit burner port more than the conventional primary burner port 4 and the openings of both side faces are widened as well as an upper opening. A premixed fuel is allowed to flow through a burner 1 and secondary air is taken in from the circumference to complete combustion as the fuel is diffused from the primary burner port 4 upward or sideward. At that time, a flame area is widened to the same combustion quantity because it is spreads sideward and a flame temperature lowers accordingly. As a result, the production of NOx is lessened. On the other hand, because jet force from the primary burner port 4 of the premixed gas is weak when the combustion is allowed to lessen further, the sideward spread of the flame can be controlled by the influence of draft.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to indoor open hot air heaters etc. using a combustion heat source (2).
The premix combustion burner used has two stages of combustion and improves the shape of the primary flame hole to reduce nitrogen oxides (hereinafter referred to as NOx).
The present invention relates to a combustion device that suppresses the occurrence of (denoted as ) and expands the combustion range.

BACKGROUND OF THE INVENTION In recent years, hot air heaters equipped with fans have rapidly become popular, and various types of combustion energy such as oil and gas are used as heat sources in addition to electricity. These heaters are required to be clean, safe, space-saving, and at the same time expand the combustion range, which is the original basic performance of a combustion-type heater, and technological development to meet these needs is progressing rapidly. There is.

Below, a conventional combustion device will be explained based on the drawings. 3(a) and (1)) are a plan view and a front view of a conventional combustion device using secondary combustion, and FIG. 4 is a longitudinal sectional view of the conventional combustion device. A nozzle 1 for ejecting gaseous fuel is provided at a position opposite to a mixing tube 3 of a burner 2, and at this time, the amount of primary air sucked by the jet of gaseous fuel ejected from the nozzle is adjusted so that the excess air ratio m is 0. Adjust the diameter of the mixing tube inlet 30 mm using a damper or the like so that the diameter is 6 to 0.9 mm.

The primary flame hole 4 of the burner 2 is provided to be covered by a vessel 7 forming a combustion chamber 5 as well as a secondary flame hole 6 consisting of a single opening.

In the combustion device configured as described above, the combustible gas in the mixing tube flows out onto the primary flame hole 4 in a state of fuel receding.
A second flame 8 is formed. The combustion gas released from the primary flame 8 contains NO as well as combustible gas that cannot be burned due to lack of oxygen. The combustible gas diffuses and mixes with the surrounding air at the secondary flame hole 6 to form a secondary flame 9 and complete two-stage combustion. In this way, in the two-stage combustion, the combustion temperature is kept lower than in the one-stage combustion and complete combustion is achieved, so the generation of NO8 can be suppressed.

However, when the amount of combustion decreases, it becomes difficult to perform two-stage combustion. The state of the flame at this time is as shown in Figures 2 (a) and (b), which show local cross-sections of the flame hole of a conventional burner. It is emitted from the slit flame hole 4 that spreads slowly to both sides, and combustion is completed while obtaining secondary air above the sulin I flame hole 4.

Problems to be Solved by the Invention However, with conventional slit flame holes, the flame surface formed (
As the surface area of the reaction zone becomes smaller, especially when the amount of combustion is small, it becomes one-stage combustion, which increases the combustion temperature and generates a large amount of nitrogen oxides such as nitrogen dioxide per unit amount of combustion. I had a problem.

The present invention solves these conventional problems,
By enlarging the openings on both sides of the slit flame hole and spreading the flame further, the flame surface actually formed is expanded, and the N
The purpose of this invention is to reduce the generation of OX and provide a cleaner indoor open combustion hot air heater.

Means for Solving the Problems In order to achieve the above objects, the combustion device such as the hot air heater of the present invention spreads the flame surface formed and lowers the temperature of the flame zone by rinsing on both sides of the flame. It has an elongated hole.

Effect The present invention has the above-described configuration, while ensuring a combustion range,
By spreading the flame surface to the top and both sides, the combustion temperature of the flame zone is lowered, making it possible to reduce the generation of N08.

Embodiment FIGS. 1(a) and 1(b) are a detailed sectional view and side view of a slit flame hole showing an embodiment of the present invention. Note that the only difference from the above conventional technique is the slit-shaped primary flame hole 4a, so only that portion will be illustrated and explained. That is,
The primary flame hole 4a has a longer slit flame hole than the conventional primary flame hole 4, and the openings on both sides are widened to the difference between the upper openings.

The principle of the above configuration will be explained. The premixed fuel passes through the burner 1 and diffuses upward and laterally from the primary flame hole 4 while taking in secondary air from the surroundings to complete combustion. At this time, the flame surface spreads laterally, so the flame area increases for the same amount of combustion, and the flame temperature also decreases accordingly. Therefore, the generation of NOx is suppressed. On the other hand, if the combustion amount is further reduced, the ejection force of the premixed gas from the primary flame hole 4 becomes weaker, so that the flame is prevented from spreading laterally due to the influence of draft. As a result, the flame surface returns to the flame state of the conventional example, and the combustion area is secured.

As described above, it is possible to reduce the generation of NOx while securing the combustion area, and it is possible to improve cleanliness and safety.

Effects of the Invention As is clear from the above examples, the present invention reduces the generation of NOx by enlarging the openings on both sides of the slit flame hole and increasing the spread of the flame. The cleanliness and safety of heaters, etc. can be improved.

[Brief explanation of the drawing]

FIGS. 1(a) and (b) are a vertical cross-sectional view and a side view showing a slit flame hole of a combustion device according to an embodiment of the present invention, and FIGS. 2(a) and (b) are a slit flame hole of a conventional example. 3A and 3C are a plan view and a front view of a conventional combustion device, and FIG. 4 is a longitudinal sectional view of a conventional combustion device. 2... Burner, 4a... Primary flame hole. Name of agent: Patent attorney Shigetaka Awano (1 person) Figure a) (α) 2--base 4α-=/Koen-7b cb) tb) Figure

Claims (1)

[Claims] The primary flame hole is formed by a plurality of slits that are opened across the horizontal plane and both sides of the burner for premix combustion, and the secondary flame hole is formed by a single opening on the upper surface and forms a combustion chamber. and one of the burners.
A combustion device characterized in that both sides of the secondary flame hole are lengthened.