JPH0713530B2 - Burning plate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a combustion plate applied to a water heater, a hot water heater, and other combustion appliances.

(Prior Art) A combustion chamber is provided with a premixed gas burner to which a mixture of air and fuel gas is supplied by a fan and a heat exchanger heated by the premixed gas burner, and the premixed gas burner is a mixing chamber of a burner body. It is known to have a combustion plate with a number of flame holes closing the front opening.

(Problems to be Solved by the Invention) However, in the premixed gas burner like the above-mentioned conventional one, there is a disadvantage that the combustion plate is easily heated, and for example, a flashback phenomenon is likely to occur, and the excess air ratio cannot be increased. There was an inconvenience.

The diameter of the flame holes in the combustion plate is about 1 mm, but depending on the type of gas, it may be 1.1 mm or conversely 0.9 mm.

Further, since the dimensions shrink during combustion in the manufacturing process of the combustion plate, the flame hole diameter before sintering is set to a value considering the reduction.

In this way, the flame hole diameter of the combustion plate is very small, and even a slight dimensional difference has a great effect on the combustibility, so the design is made in consideration of the gas species and the reduction of the diameter during the manufacturing process.

However, combustion plates are often piled up and handled at the time of manufacturing, transportation, etc., so that the peripheral edge of the exit of the flame hole from which gas is ejected is chipped. Therefore, it was required that the outlet of the flame hole would not be chipped during handling during manufacturing and transportation, and cushioning materials were used, and careful handling was performed.

(Means for Solving the Problems) The present invention is proposed in order to eliminate the above inconvenience, and is a combustion plate that closes the front opening of the mixing chamber of the burner body of the gas burner, the combustion plate from the back surface. In a device having a large number of flame holes penetrating the surface thereof, an air flow passage for flowing air in the combustion plate and a projection protruding from the surface of the combustion plate are formed, and the air flow passage is formed on an upper surface of the projection. A jet port for jetting the air from the above is provided, and in the second aspect, the projection has a bank shape extending in the longitudinal direction on the surface of the combustion plate.

(Operation) The present invention has the above-described configuration. In the combustion plate according to claim 1, an air flow passage and a combustion passage through which air used for cooling the combustion plate and for diluting the combustion gas in the combustion casing are provided. Since the ejection port that communicates with the combustion chamber in the housing is provided on the upper surface of the protrusion that is higher than the flame hole, the stack can be stacked by the protrusion when stacking during manufacturing or transportation of the combustion plate. Since the outlet does not contact the back surface of the upper combustion plate, it does not damage the flame holes. The jet port from which air is jetted contacts the back surface of the upper combustion plate, but even if the jet port is chipped, the air will only jet from here, so no inconvenience will occur.

In the combustion plate according to the second aspect of the present invention, since the protrusion is in the shape of a bank extending in the longitudinal direction, the flame in the outermost flame hole of the combustion surface is subjected to a flame holding action over a long distance at the protrusion to ensure stable combustion. can get.

(Example) Next, the Example of this invention is described based on drawing.

FIG. 1 shows an example in which the combustion plate according to the first embodiment of the present invention is used in a water heater, and 1 shows a combustion casing of the water heater. In the combustion casing 1, a heat exchanger 2 and a heat exchanger 2 are provided. And a premixed gas burner 3 for heating the.

The burner 3 is composed of a burner body 3d having a mixing chamber 3e and a combustion plate 3a closing a front opening of the mixing chamber 3e, and a mixture of air and gas is fed into the mixing chamber 3e by a fan 4a.
It is configured to be forced to be insufflated by.

The heat exchanger 2 comprises a first heat exchanger 2a in the lower stage and a second heat exchanger 2b in the upper stage, and the water fed from a water supply pipe 5 connected to the upstream end of the first heat exchanger 2a is made into hot water. The structure is such that the two heat exchangers 2b are fed to the hot water discharge pipe 6 connected to the downstream end thereof.

The combustion exhaust gas is discharged to the outside from the exhaust port 1a in the upper part of the combustion casing 1.

Reference numeral 7 denotes a gas supply path in which the nozzle 7a at the tip is faced to the suction port 4a of the fan 4.

The combustion plate 3a has a large number of flame holes 3b penetrating from the back surface to the front surface, and the flame holes 3b are provided inside the combustion plate 3a.
An air flow passage 8 is formed so as to avoid. 9 is a fan for supplying air to the air flow passage 8. Further, the combustion plate 3a is formed with a protrusion 13 protruding from the surface thereof. Reference numeral 14 denotes an ejection port provided on the upper surface of the protrusion 13, and the ejection port 14 is connected to the air flow passage 8 to supply air to the combustion chamber 10.

Since the projection 13 is provided on the surface of the combustion plate 3a in this way, even if the combustion plates 3a are stacked during manufacturing, transportation, etc. of the combustion plate, since the projections 13 overlap each other, the exit of the flame hole 3b is Since the combustion plate 3a does not come into contact with the back surface of the upper combustion plate, the combustion plate 3a does not come into contact with another combustion plate 3a and the outlet of the flame hole 3b is not chipped and enlarged. Therefore, no combustion failure or the like will occur during actual combustion. Further, since the air ejection port 14 is higher than the outlet of the flame hole 3b, the air from the air ejection port 14 does not directly contact the outlet of the flame hole 3b and the combustion is not unstable.
Then, the ejection port 14 contacts the back surface of the upper combustion plate when stacked, but even if the ejection port 14 is chipped due to this, the ejection port 14 is an air ejection port, so that no inconvenience occurs during combustion.

FIG. 2 shows the use in another water heater of the present invention, which differs from the embodiment shown in FIG. 1 except that the tip of the gas supply passage 7 is exposed inside the fan casing 4b of the fan 4. It's not particularly different.

In the combustion plates of the above two use examples, as shown in FIG. 3, a truncated cone-shaped projection 13 is provided between the flame holes 3b, 3b, and each projection 13
A spout 14 was provided for each. However, as shown in FIG. 4, it is also possible to form the projection 13 in the longitudinal direction, to arrange the ejection ports 14 in this row, and to provide the flame holes 3b group between the projections 13 by blocking. Also in this embodiment, since the projection 13 is formed on the surface of the combustion plate 3a and the jet port 14 is provided on the upper surface of the projection 13, the same operation and effect as the previous embodiment can be obtained.

FIG. 5 shows still another embodiment of the present invention, in which the air flow passage 8 penetrates through the portion provided with the protrusion 13 provided on the front surface of the combustion plate 3a and the portion provided with the protrusion 3c provided on the back surface. It was composed of holes, and its upper end was used as the jet port 14.

The fan 4 supplies the premixed gas to the premixed gas burner 3 and also supplies the air to the air flow passage 8. To explain this, the fan casing 4b of the fan 4
Each of the two compartments inside is equipped with a rotor 4c, and both rotors
4 c, 4 c are configured to be of a type in which one motor 4 d is commonly used, and the inside of the duct 15 that connects each of the two compartments of the fan 4 and the back surface of the combustion plate 3 a with the partition plate A It was partitioned by to form an air passage and an air-fuel mixture passage.

Then, the nozzle 7a is exposed to the suction port 4a of the one chamber of the fan 4, and the mixture of the air blown from the one chamber of the fan 4 and the gas from the nozzle 7a is sent to the flame hole 3b, and The flow passage 8 is connected to the air passage so that the air blown from the other chamber of the fan 4 is jetted into the combustion chamber 10 from the jet port 14 at the upper end of the air flow passage 8.

In this example of use, the ratio of the amount of air to the amount of air-fuel mixture is constant, but as shown in FIG. 6, the tip 7a of the gas supply passage 7 is faced inside the fan casing 4b, and the suction port 4a is exposed. Bellmouth
It is more preferable to face 11 and move the bell mouth 11 as shown by the arrow, because the ratio of the amount of air to the amount of air-fuel mixture can be varied.

FIG. 7 shows another embodiment of the present invention. In this embodiment, the air flow passage 8 is constituted by a through hole that vertically penetrates the protrusion 13 portion provided on the surface of the combustion plate 3a, The upper end of the through hole serves as the jet port 14 and the lower end has the same height as the back surface of the flame hole 3b. The lower end of the air flow passage 8 is closed by a groove plate-shaped partition plate A, and the fan 4 is connected to the back surface of the combustion plate 3a of the burner 3, and the second surface connected to the air flow passage 8 is connected to the back surface of the combustion plate 3a. A branch wall 12 for branching into a passage 4b-2 and a first passage 4b-1 connected to the flame hole 3b is provided, and a gas nozzle 7a is made to face the first passage 4b-1 so that a mixture of gas and air is formed in the flame hole. It was supplied to 3b.

The air flow passage 8 is communicated with the second passage 4b-2 through the upper portion of the partition plate A so that the air from the fan 4 is ejected.
Then, air was ejected from the ejection port 14 to the combustion chamber 10. As a result, it is possible to supply a mixture of gas and air to the flame holes 3b by the single common fan 4 and to eject air from the ejection port 14 to the combustion chamber 10 via the air flow passage 8.

Since the peripheral wall of the protrusion 13 serves as a flame retaining wall, the combustion of the burner 3 is further improved.

FIG. 8 shows still another embodiment. In this embodiment, a projection 13 surrounding the surface of the combustion plate 3a and a long projection 13 provided inside the surface of the combustion plate 3a are provided. A through hole is provided in the combustion plate 3a where the protrusion 13 is provided so as to vertically penetrate the combustion plate 3a along the protrusion 13, and the through hole serves as the air flow passage 8 and the upper end thereof is jetted. Exit 14
Moreover, the recessed groove 8a is provided on the back surface of the combustion plate 3a at a position facing each protrusion 13 thereof. Also in this case, even if the combustion plates are stacked, a gap is formed between the protrusions 13 and 13 by using the protrusion 13 as a spacer, and the outlet of the flame hole 3b faces the gap, so that the outlet of the flame hole 3b is protected.

Further, since the ejection port 14 is higher than the outlet of the flame hole 3b, the air from the ejection port 14 does not directly contact the outlet of the flame hole 3b, and the protrusion 13 is further in the form of a bank extending longitudinally to form a combustion surface. Among the flames of many flame holes, the flame of the outermost flame hole is subjected to a flame holding action over a long distance by this protrusion, and stable combustion can be obtained.

Reference numeral 8b is a lid body that covers the concave groove 8a from the back surface, thereby forming a passage connecting the air flow passages 8.

According to each of the above-described embodiments, (1) even if the combustion plates 3a are stacked at the time of manufacturing or transportation, the protrusions 13 are formed on the surface of the combustion plates 3a. Since there is a gap in the hole, and the outlet of the flame hole 3b faces the gap, the outlet of the flame hole 3b is chipped and the outlet of the flame hole does not become large, so a stable combustion plate can be obtained. .

(2) In addition, if a burner using this combustion plate is incorporated into a water heater and burned, the jet port 14 is formed on the upper surface of the projection 13 and is at a high position not flush with the outlet of the flame hole 3b. Therefore, the air from the ejection port 14 does not directly reach the outlet of the flame hole 3b and does not adversely affect the combustion. Further, when the protrusion 13 is particularly long, it also acts as a flame retaining wall.

(B) The combustion plate 3a is cooled by the air in the air flow passage 8, and the combustion plate 3a is prevented from being heated. As a result, the flashback phenomenon can be prevented.

After boiling is prevented.

The excess air ratio λ of the primary air can be made constant.

The material of the combustion plate 3a is not limited.

(3) Further, air is introduced into the combustion chamber 10 via the air flow passage 8, and a large excess air ratio λ in the combustion chamber 10 can be obtained.

As a result, the combustion gas is not diluted and the heat exchanger 2 or the like is not drained.

When the fire of the burner 3 is reduced, the thermal efficiency can be lowered as compared with the conventional one, and the hot water discharge capacity can be adjusted over a wide range for use.

White smoke can be prevented.

The combustion plate is manufactured by the following two methods, for example.

The first method is to embed a plurality of perpendicular thermoplastic core materials in the raw material or to embed the heat-soluble core material in the raw material in a meandering manner, mold it, and after forming the flame holes 3b. , Sintering is performed. In this case, since the core material melts and flows out during sintering, the space formed after the core material flows out is used as the air flow passage 8.

The second method is to bond a plate-like body of the same quality having a jetting tool 14 formed so as to cover the groove to the upper surface of the plate-shaped body having the groove and the flame hole 3b, and sinter this. Let me do it. In this case, the groove is used as the air flow passage 8.

(Effect of the invention) As described above, according to the combustion plate of the first aspect, the projection is formed on the surface of the combustion plate having a large number of flame holes, and the combustion plate is cooled on the upper surface of the projection. Since the ejection port of the air flow passage through which the device used for diluting the combustion gas in the combustion casing is provided, (1) the protrusion higher than the outlet of the flame hole serves as a spacer when stacking the combustion plates. In addition, the outlet of the flame hole is protected, and the effect of not causing inconvenience such as chipping of the outlet of the flame hole is produced, and (2) since air is ejected from the ejection port higher than the outlet of the flame hole, It is possible to obtain a combustion plate capable of stable combustion without air directly hitting the outlet of the flame hole.

According to the combustion plate of claim 2, since the protrusion has a bank shape extending in the longitudinal direction, the flame of the outermost peripheral flame hole of the flame holes forming the combustion surface has a longer distance by the protrusion. A stable fuel is obtained by being subjected to a flame holding effect over a period.

[Brief description of drawings]

FIG. 1 is a sectional front view showing an embodiment when the fuel plate of the present invention is applied to a water heater, FIG. 2 is a sectional front view when applied to another water heater, and FIGS. Is a cutaway front view and a perspective view showing a main part of the embodiment shown in FIG. 1 and FIG.
FIG. 5 is a perspective view of a main part of another embodiment, FIG. 5 is a cutaway front view of another embodiment, FIG. 6 is a cutaway front view of a modification of the fan portion of FIG. 5, and FIG. 8 is a cutaway front view of the embodiment of FIG.
The figure is a perspective view of still another embodiment. 3a ... Combustion plate, 3b ... Flame hole 8 ... Air flow passage, 13 ... Projection 14 ... Jet port

Claims (2)

[Claims] 1. A combustion plate for closing a front opening of a mixing chamber of a burner body of a gas burner, wherein the combustion plate has a large number of flame holes penetrating from the rear surface to the front surface, and the air is supplied to the combustion plate. A combustion plate, characterized in that an air flow passage for flowing and a projection protruding from a surface of the combustion plate are formed, and an ejection port for ejecting air from the air flow passage is provided on an upper surface of the projection. 2. The combustion plate according to claim 1, wherein the protrusion has a bank shape extending longitudinally on the surface of the combustion plate.