JPH0532645B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a high-load combustion device (gas burner) used in gas appliances such as gas instantaneous water heaters.

[Prior art and its problems]

Bunsen gas burners, which are often used in gas appliances, require secondary air to complete combustion and have a relatively long flame length. Therefore, a large combustion space is required in the upper part of the gas burner, resulting in an increase in the size of the appliance.

Therefore, the use of a premixed gas burner has been proposed as a means to improve these drawbacks.
However, even in the case of a premixed gas burner, a certain amount of combustion space is required above the burner, and the size of the burner itself is not much different from a Bunsen type, so there is a limit to the miniaturization of gas appliances.

Furthermore, as a means of downsizing gas appliances, there is a proposal (high-load combustion method) to use a ceramic gas burner and increase the amount of combustion per unit area, thereby downsizing the gas burner accordingly.

However, even with this method, if the combustion amount is increased, the flame becomes unstable, and if the amount is increased beyond a certain point, oscillatory combustion will occur, so there is still a limit to miniaturization. In addition, the diameter of the flame holes is small, about 1 mm, and many of these are provided on the flame hole surface, and the flame is stabilized by the glowing action of the flame hole surface, so the lift phenomenon is likely to occur in this case as well. Therefore, there is a limit to the increase in combustion amount.

Furthermore, if the flame hole surface is made red hot to stabilize the flame as described above, a large amount of residual heat is produced, and in the case of a gas instantaneous water heater, there is a drawback that the so-called after-boiling phenomenon becomes noticeable.

Also, if the flame hole surface is made red hot as described above,
The flame formed in each flame hole is not independent, but the flame spans multiple flame holes, and the flame length becomes long, making it impossible to maintain an appropriate distance from the heat exchanger. be.

The object of the present invention is to propose a high-load combustion device that does not have the above-mentioned drawbacks.

[Configuration of the present invention]

The present invention employs the following configuration as a means for achieving the above object.

A flame-holding wall is formed around the rectangular flame hole surface, and a pressure regulating space is formed by inserting a rectifying plate with openings on the back side of the flame hole surface, and premixed gas is supplied into this pressure regulating space by a blower. In a high-load combustion device configured to
The distance between the centers of each flame hole must be in the range of 3 to 5 mm, the distance between the outer periphery of each flame hole and the flame holding wall around the flame hole surface must be within 2 mm, and the height of the flame holding wall is in the range of 8 to 15 mm, the opening of the rectifying plate inserted into the pressure regulating space is approximately the same as the total area of the burner flame hole, and the distance between the rectifying plate and the flame hole surface is in the range of 3 to 10 mm. A high-load combustion device characterized by:

In the above configuration, it is essential that the flame stabilizing walls do not come into close contact with each other at the corners, that is, the four corners, and the determination of this spacing depends on the coefficient of thermal expansion.

Ceramic is suitable as the material for the flame-holding wall.

Next, if the diameter of the flame hole of the burner exceeds approximately 2 mm, flashback may occur in gases with a high combustion rate, and if it is smaller than 1.2 mm, there will be a gap between each flame hole as described below. Due to distance constraints, the total area of the flame holes becomes too small, making it impossible to increase the amount of combustion per unit area of the burner.

Next, the distance between the centers of each flame hole should be 3 mm or more and 5 mm.
The following are good. If it is less than 3 mm, the burner surface tends to become red hot, and if it is less than 2 mm, the flames in each flame hole may be connected to form a single sheet-like flame. Further, if the thickness is 5 mm or more, the mutual stabilizing effect of adjacent flames is reduced, and lift is likely to occur.

Next, flame lift can be prevented by providing a flame-holding wall with a height of 8 mm or more and 15 mm or less around the burner surface. If the height is less than 8 mm, the flame holding ability will decrease, and if it is more than 15 mm, the upper part of the flame holding wall will become red hot from the flames.

Next, the position and arrangement of the flame hole provided closest to the flame-holding wall is extremely important for preventing lift. The distance between the outer periphery of the flame hole closest to the flame-holding wall and the flame-holding wall must be 2 mm or less; if it is 2 mm or more, the flame above the flame hole is likely to lift, and as a result, the flame over the flame hole surface is likely to be lifted. The inflammation goes out. Also,
Lift can be effectively prevented by arranging the flame holes in a grid pattern and by arranging all the flame hole rows adjacent to the flame-holding wall at equal distances from the flame-holding wall.

Next, in order to prevent oscillatory combustion, it is necessary to
It is effective to place a current plate with an opening area comparable to the total area of the burner flame holes at a position of mm or more and 10 mm or less. The opening of the current plate may be a large number of flame holes of an appropriate size, but if the distance from the bottom of the burner flame hole surface is 3 mm or less, the flames on the flame holes facing the openings on the current plate will be connected to each other. The flame becomes long, and an independent flame cannot be formed in each flame hole, resulting in a long flame.

On the other hand, if it is 10 mm or more, the volume of the space between the rectifying plate and the burner flame hole surface becomes large, and the vibration combustion suppressing effect decreases. The total area of the openings on the current plate may be approximately the same as the total area of the flame holes, and a plurality of openings may be installed.

Next, to suppress oscillating combustion and flashback,
It is effective to set the thickness of the burner flame hole surface to 8 mm or more.

[Effect]

The premixed gas is supplied to the pressure regulating space by a blower, and the premixed gas supplied to the pressure regulating space is further ejected from the flame hole through the opening of the baffle plate and combusted.

〔Example〕

Fig. 1 is a perspective view of a high-load combustion device (gas burner) according to the present invention, and Fig. 2 is a cross-sectional view taken along the line A-A'. Flame holes 2 with a diameter of 1.5 mm are provided in a grid pattern, and the distance between the centers of each flame hole 2 is 3 mm. The burner flame hole surface 1 is surrounded by a flame holding wall 3 with a height of 8 mm, and the distance between the outer periphery of the flame hole 2 closest to the flame holding wall 3 and the flame holding wall 3 is 2 mm,
They are all equidistant from the flame-holding wall 3. In addition, when the flame holes in the central part are arranged in a staggered manner, a new flame holding hole 2 is added approximately in the center of the flame holes 2'' that are close to the flame holding wall 3 and have an excessively large interval. The flame holding ability is improved by providing the distance between the wall 3 and the outer periphery of the flame holding flame hole 2 to be 2 mm or less.A rectifying plate 5 is inserted into the pressure regulating space 2a on the back side of the flame hole surface 1. The current plate 5 has an opening 4 formed therein.
The total area of the openings 4 is approximately the same as the total area of the flame holes 2. The diameter of the opening 4 may be larger than the diameter of the flame hole 2, but even in that case, an independent flame can be formed in each flame hole 2 by separating it from the back surface of the flame hole surface 1 by 3 mm or more. . Figure 4 shows the flame shape when the distance between the rectifying plate 5 and the back surface of the burner flame hole surface 1 is 1 mm.
The flames on the flame holes 2 opposing the flames are connected to each other to form one flame 6, which is longer than the flame 7 formed independently. On the other hand, when the distance is set to 3 mm or more, as shown in FIG. combustion is obtained.

The flame-holding wall 3 is composed of independent ceramics on each side around the rectangular flame hole surface 1, and is abutted at each joint, with some play.

8 in the figure is a blower for feeding the premixed gas into the pressure regulating space 2a, and as an example, when the premixed gas at the stoichiometric air ^ratio is
/min is being fed.

A metal fitting 9 fixes the flame-holding wall 3, and a heat-resistant gasket 10 is inserted between the flame-holding wall 3, the metal fitting 9, and the burner body 1a for gas sealing.

[Effects of the present invention]

As described above, the present invention forms a flame-holding wall around the flame hole surface to protect the flame formed in the flame hole, especially the base. Burns stably on the pore surface. As a result, there is no need to worry about lift even if the combustion amount is increased.

Next, the height of the above-mentioned flame-holding wall should be 8 mm or more, and 15 mm.
By setting the temperature below, the flame stabilizing effect is achieved and the upper part does not become red hot due to excessive heat, so when the combustion device according to the present invention is used in a gas instantaneous water heater, there is little after-boiling.

Next, by setting the distance between the flame-holding wall and the surrounding flame holes to 2 mm or less, the surrounding flame would normally become unstable due to the vortex of the surrounding air, but the distance between the flame-holding wall and the surrounding flame is small and the generation of vortices is suppressed, resulting in stability.

Next, by setting the thickness of the flame hole surface to 8 mm or more, the interval between the centers of each flame hole to 3 to 5 mm, and the interval to the pressure regulating space to 3 to 10 mm, lift and vibration are avoided even when the combustion amount is increased. This eliminates the occurrence of combustion, making it possible to perform even higher-load combustion. Therefore, gas burners and gas appliances can be made smaller.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a high-load combustion device (gas burner) according to the present invention, Fig. 2 is a sectional view taken along line A-A',
Figure 3 is a comparative plan view showing a part of the flame hole surface;
FIG. 5 is a partial sectional view of the flame hole surface showing the combustion state. 1... Flame hole surface, 2... Flame hole, 3... Flame holding wall, 4
...Opening, 5...Rectifier plate, 6, 7...Flame, 8...
...Blower, 9...Metal fittings, 10...Heat-resistant packing.

Claims (1)

[Claims] 1. A flame stabilizing wall is formed around the rectangular flame hole surface, and a pressure regulating space is formed by inserting a rectifying plate with openings on the back side of the flame hole surface, and the premixed gas is introduced into this pressure regulating space using a blower. In the high-load combustion equipment configured to supply the flame, the thickness of the flame hole surface must be 8 mm or more, the diameter of the flame hole must be in the range of 1.2 to 2.0 mm, and the distance between the centers of each flame hole must be 3 to 3 mm. The distance between the outer periphery of each flame hole and the flame holding wall that exists around the flame hole surface must be within 2 mm, and the height of the flame holding wall must be within the range of 8 to 15 mm. The opening of the rectifying plate inserted into the pressure regulating space is approximately the same as the total area of the burner flame hole, and the distance between the rectifying plate and the flame hole surface is 3 to 10 mm.
A high-load combustion device characterized by a range of