JP2852597B2 - Ignition device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
By using an air-fuel mixture ejected from a flame hole portion in a mode in which a high gas concentration portion and a low gas concentration portion coexist, a gas burner of a so-called lean-burn type as a whole, and particularly relates to an ignition device thereof. is there.

[0002]

2. Description of the Related Art In recent water heaters and the like, the amount of combustion has increased, and the problem of NOX in gas burners has been highlighted. Therefore, in order to solve this problem, a method of performing lean combustion, that is, a method of performing combustion under a condition of low gas concentration, has recently been adopted. Usually, when the gas concentration is low, the flame formed in the flame hole is easily lifted. Therefore, in order to secure the stability of combustion by preventing this lifting, a gas burner having a configuration in which a flame hole having a high gas concentration and a flame hole having a low gas concentration coexist, that is, a so-called light and shade burner has been proposed. This is to secure the stability of combustion of the entire flame hole part by holding the unstable flame formed in the flame hole with low gas concentration by the stable flame formed in the flame hole with high gas concentration. is there.

On the other hand, recent ignition devices for gas burners include:
A direct ignition method using a spark is adopted. As a result, at the time of ignition, if the gas concentration is low, the ignition performance is extremely reduced. In the case of the above-mentioned light and dark burners for realizing the lean burn, sufficient ignition performance cannot be secured simply by making the discharge electrode of the spark ignition device correspond to the flame hole.

[0004] The present invention has been made in view of the above-mentioned point, and it is stated that a first flame hole (H ₁ ) having a high gas concentration and a second flame hole (H ₂ ) having a low gas concentration are formed in a flame hole portion. It is an object of the present invention to improve the ignition performance of the "ignition device for the gas burners alternately arranged in parallel".

[0005]

The technical means of the present invention for solving the above-mentioned problem is as follows: "The cathode portion (T) of the electrode plate (T) is formed along the outer edge of the first flame hole (H ₁ ) at the edge of the flame hole portion. T ₁₎ disposed in the first fire hole (the upper to the first fire hole of _{H 1)} (first distance from _{H 1)} (x), inside of the first fire hole _{(H 1)} electrode portion of the ignition plug (P) and _{(P 1)} provided from the second burner ports above the second burner ports _{(H 2) (H 2)} at a second distance (y),
The first distance (x) is smaller than the second distance (y), and the third distance (z) between the cathode part (T ₁ ) and the electrode part (P ₁ ) is the second distance (z). The distance (y) is smaller than the distance (y) to discharge from the electrode part (P ₁ ) to the cathode part (T ₁ ) ”.

[0006]

The above technical means operates as follows. A gas mixture having a high gas concentration is ejected from the first flame hole (H ₁ ) at the end of the flame hole portion, and a gas mixture having a low gas concentration is ejected from the second flame hole (H ₂ ) inside the first flame hole (H ₁ ). The electrode portion (P ₁ ) is located above the second flame hole (H ₂ ), and at the time of ignition, the discharge path for the gas mixture ejected from these flame hole groups has a low gas concentration. It is a path from a part to a high part. Therefore, at the time of ignition discharge, the discharge passes through an appropriate ignition concentration range which always exists in any of the paths, and good ignition is performed. The discharge distance (third distance (z)) from the electrode part (P ₁ ) to the cathode part (T ₁ ) is:
Since the distance is smaller than the second distance (y) from the electrode portion (P ₁ ) to the second flame hole (H ₂ ), discharge leakage from the electrode portion (P ₁ ) to the gas burner during discharge is prevented.

After ignition, the flame in the second flame hole (H ₂ ) is stably held by the stable flame formed in the first flame hole (H ₁ ), and the entire flame hole portion (B ₂ ) The flame that has spread to the above is maintained in a stable combustion state.

[0008]

[Effect] There is an appropriate ignition concentration range in any one of the ignition discharge paths, and a discharge leak from the electrode portion (P ₁ ) to the gas burner at the time of discharge is prevented, so that the ignition performance is improved. Since the gas concentration is high, the flame at the time of ignition is first formed in the stable first flame hole (H ₁ ), so that the flame formed in the entire flame hole immediately after ignition is also stable. That is, combustion immediately after ignition is stabilized.

[0009]

Next, an embodiment of the present invention will be described in detail with reference to the drawings. In this embodiment, the present invention is applied to a combustion device of a water heater, and this water heater has a heat exchanger above a burner box (1) having a combustion chamber as shown in FIG. It has a configuration in which cans (K) with built-in vessels are connected.

This can body (K) has a well-known structure, and a heat exchange section having a structure in which a heat absorbing tube having a number of fins is meandering is arranged near an open end of a cylindrical can body. An exhaust device (not shown) is connected to the upper end of the body. Burner box (1)
A gas burner (B) is built in a cylindrical air chamber, and a gas supply pipe (N) arranged on a side of the gas burner (B) and a combustion air to the gas burner (B) are supplied. fan
Incorporate air supply devices for forced air supply from (F).

[0011] The burner box (1) is formed as a whole with a bottomed rectangular tube, and has a rear wall and both side walls integrated into a box body (1a).
And a front plate (1b) for closing the front opening, and a bottom plate (1c) for closing the lower end of the cylindrical body constituted by these. As shown in FIG. 3, the box main body (1a) has a configuration in which flange portions (10a) and (10b) having upright pieces (11) are protruded around the upper and lower edges. The subject (1a)
Once, as shown in FIG. 2, flange-equivalent portions (La) (L) corresponding to the flange portions (10a) (10b) from both upper and lower sides of the metal rectangular plate.
a) is a dish-like body having an upright piece (11), which is manufactured by bending the dish into a U-shape, and the upper flange portion (10a) is formed by the flange equivalent portion (La) bent in this manner. Flange front (1
9) are connected to form a rectangular annular flange portion (10a) as a whole.

When the rectangular plate having the flange-equivalent portions (La) and (Lb) is bent in a U-shape, depending on the bending curvature, the bent-equivalent portion becomes an obstacle in any case. . Therefore, the flange portion of the lower become the flange corresponding portion (10b) in (Lb), a range corresponding to the bent portion is a notch (L _1), a flange corresponding portion corresponding to the upper flange portion (10a)
In (La), a tongue piece (L ₂ ) is left at the center of a range corresponding to the bent portion, and both sides thereof are cutout portions (L ₁ ). The tongue piece (L ₂ ) is set to have a shape in which a band-like member having a constant width is provided with an upright piece (11) similarly to the cross section of the flange equivalent part (La).

The flange equivalent part (La) and the flange front part (1)
9) is joined by means such as spot welding or the like, but in the continuous state, the upper surface of the flange equivalent portion (La) and the upper surface of the flange front portion (19) are flush with each other in FIG. As shown in the figure, the front end of the flange (19)
A step (19a) corresponding to the thickness of (La) is provided. The burner box (1) thus constructed has a can body (K) above it.
A mounting flange (K ₁ ) is provided around the lower end of the can body (K), and the mounting flange (K ₁ ) is set to a size that can be just fitted into the upright piece (11). Then, the can body (K) pre-assembled into a predetermined configuration is heat-resistant packing (G
₁ ) is interposed between the flange portion (10a) and the flange (K ₁ ) and connected by caulking, screwing, or the like.

Since the upper surface of the flange portion (10a) is formed as a uniform plane, the can body (K) and the burner box
The confidentiality of the connection with (1) is ensured. The secret may be a seal that blocks combustion exhaust, but heat resistance is required. For example, glass wool or asbestos is used as the heat-resistant packing (G ₁ ). These materials are very brittle.

Accordingly, in the portion corresponding to the notch (L ₁ ) of the corner portion of the flange portion (10a), the lower surface of the heat-resistant packing (G ₁ ) does not contact the flange portion (10a). The heat-resistant packing (G ₁ ) tends to come off and wins.
However, in the above-described embodiment, the corner portion of the flange portion (10a) has the notch portions (L ₁ ) and (L ₁ ) set relatively small, and the notch portions (L ₁ ) and (L ₁ ) There is a tongue piece (L ₂ ) in between, and the upright piece (11) at the tip of the tongue piece (L ₂ ) is in contact with the edge of the heat-resistant packing (G ₁ ), whereby the heat-resistant packing (G ₁ )
Is held, and the shift to the outside in the above situation can be prevented. The range of the notch (L ₁ ) is the flange (10
a) instead of being distributed over the entire width of
Since there is a small flange portion (L ₃ ) following the flange portion (10a) in the inner peripheral portion, the heat-resistant packing (G ₁ ) is clamped by the flange portion (10a) and the flange (K ₁ ) over the entire area.

A gas burner (B) is stored in the burner box (1).
The gas burner (B) is shown in FIGS. 5 and 6.
As shown, the elongated flame hole (B_Two), And a number of flat
Burner only (B₁) Are arranged side by side in the burner box (1).
Each burner alone (B₁) Is the so-called shade burner
I have. Therefore, the flame hole (B_Two) Indicates that the gas concentration is high.
The first flame hole (H₁) And gas concentration
The second flame port (H_Two) And left and right are parallel
The flame hole (B_Two)
Highly concentrated first flame hole (H₁) (H₁). In addition, this dark
For light burners, burner body with high gas concentration and gas concentration
Burner body configuration with a low burner body
, And each nozzle is separately inserted into the primary air port of each burner body.
(N₁) (N ₁). Gas from each nozzle
By setting the volume and the primary air suction ratio to predetermined values,
A separate gas-air mixture is created,
Flame hole (B_Two) Is the first flame hole (H
₁) And the second flame hole (H_Two).

The gas burner (B) is composed of a large number of burners (B ₁ ) and (B ₁ ) constructed as described above, and these burners are integrally assembled by a burner assembling frame. The frame body has a front plate (21) and a rear plate (22).
And a second dispersion plate (23) connecting the lower ends thereof and having a large number of through holes, wherein the front plate (21) and the rear plate (22) are provided.
Are connected to each other by side plates (24) and (24) to form a rectangular frame as a whole. In the assembled state, a burner block as shown in FIGS. 5 and 6 is obtained.

As shown in FIG. 1, the front plate (21)
Burner only (B₁The opening (25) matches the primary air port.
And housed in the burner box (1)
The gas supply housed in the burner box (1)
Numerous nozzle holes (N ₁) And the opening (25) are separate
Oppose. The gas burner is installed on the bottom plate (1c) of the burner box (1).
Air supply fan (F) is installed below (B).
Above the first dispersion plate at a predetermined interval.
(12) is arranged and fixed, and the burner is attached to the first dispersion plate (12).
The block is placed and fixed.

And a second dispersion plate of the burner block.
(23) is mounted and fixed at a predetermined interval with respect to the first dispersion plate (12). Therefore, as shown in FIGS. 1 and 7,
A skirt portion (13) hangs from a rear side and left and right sides of the first dispersion plate (12), and the skirt portion (13) is a burner box.
It comes into contact with the inner peripheral side wall of the box main body (1a) of (1). Therefore, the bottom plate
A predetermined space that opens forward is formed between (1c) and the first dispersion plate (12), and a part of the combustion air supplied from the air supply fan (F) is opened to the front. 13a) is supplied as primary air to the front empty space (14) of the burner block, and the other part is connected to the first dispersion plate (12) through a large number of through holes of the first dispersion plate (12). It is supplied to the space between the two dispersion plates (23),
The air is supplied as secondary air to the storage portion of the gas burner (B) through the through hole of the second dispersion plate (23).

As shown in FIGS. 1 and 7, the second dispersion plate
In (23), a hanging piece (23a) is formed to extend from both left and right sides and a rear side. On the other hand, a rising piece (12a) bent upward is continuously provided at the front end of the first dispersion plate (12). The left and right widths of the rising piece (12a) are set to predetermined lengths in relation to the left and right widths of the box main body (1a). Between the both side walls of the main body (1a), a gap is formed having a width through which the left and right hanging pieces (23a) can be inserted.

At the lower end of the front plate (21), a plate-like stopper (21a) is attached to the entire left and right area of the second dispersion plate (23), and is provided rearward from the lower end of the front plate (21). The hanging piece (23a) on the rear side of the second dispersion plate (23)
a) With the rising piece (12) facing the inner surface of the rear wall
a). When assembling the gas burner (B) into the burner box (1), before assembling the front plate (1b), the gas burner (B) comes into contact with the inner peripheral surface of the box main body (1a) and is placed on the bottom plate (1c). The first dispersion plate (1
A burner block is inserted into the upper surface of 2).

Therefore, the hanging piece (2) on the rear side of the second dispersion plate (23)
3a) and the back of the rising piece (12a) of the first dispersion plate (12).
And pass the left and right hanging pieces (23a) and (23a) through the gap.
Insert the burner block in the same way as
The stopper (21a) and the rising piece (12a) face each other
At the same time, the hanging piece (23a) on the rear side is the inner surface of the back wall (1a).
Is in contact with. As already mentioned, the burner block
Means a number of burners alone (B ₁), To which a frame etc.
Is equipped, the total weight is heavy and handling is troublesome
However, as described above, a part is placed on the first dispersion plate (12) and
Just push in while riding to position in place
Therefore, the assembling work of this is easy.

Further, the vacant space below the first dispersion plate (12) is brought into contact with the skirt portion (13) and the inner peripheral surface of the box main body (1a), so that the left and right side portions of the first dispersion plate (12) are formed. And air leakage from the rear side hardly occurs. Also, the space between the first dispersion plate (12) and the second dispersion plate (23) is also surrounded by a hanging piece (23) and a box.
(1a), the stopper (21a) and the rising piece (1
2a), the air is reliably surrounded, so that air leakage from the periphery of the second dispersion plate (23) hardly occurs. Accordingly, the degree of dispersion of the secondary air by the first distribution plate (12) and the second distribution plate (23) is made uniform, and the dispersion of the primary air distribution ratio to the front empty space (14) can be eliminated.

As described above, when the burner block is assembled, parts such as the gas supply pipe (N) are assembled in the front empty space (14), and the main body (1a) is formed by the front plate (1b). The front opening (1b) is closed by the gas burner.
Upper plate (15) for closing the front that coincides with the upper area of (B)
And a lower plate (16) for closing the front surface of the lower region, and the upper plate (15) has a discharge mechanism of an ignition device,
The detector (S) of the flame detector is attached.

The detector (S) is mounted such that the detector (S ₁ ) is located above the front of the flame hole (B ₂ ) of the second burner (B ₁ ) from the end, The other discharge mechanism section includes an electrode plate (T) and a spark plug (P), and corresponds to the flame hole section (B ₂ ) of the fourth burner unit (B ₁ ) from the end. The ignition plug (P)
An electrode portion (P ₁ ) obtained by bending a wire into an L-shape is provided, and the tip of the electrode portion (P ₁ ) is on the side of the flame hole portion (B ₂ ) as shown in FIGS. 5, 6 and 8. It is mounted so as to be located above the second gas hole (H ₂ ) having a low gas concentration inside the first gas hole (H ₁ ) at the edge. The electrode plate (T) facing the electrode portion (P ₁ ) is similarly attached to the upper plate (15), and the tip of the electrode plate (T) is made of the first burner (B ₁ ), that is, the first gas having a high gas concentration. It contacts the outer edge of the flame hole (H ₁ ). The cathode (T ₁ ) provided at the tip of the electrode plate (T) is located slightly above the side edge of the flame hole (B ₂ ). As is clear from FIG. 8, the cathode part (T ₁ ), the electrode part (P ₁ ), the first flame hole (H ₁ ), and the second flame hole (H ₂ )
Is as follows. That is, the first distance (x) from the first flame hole (H ₁ ) of the cathode portion (T ₁ )
Is smaller than a second distance (y) of the electrode portion (P ₁ ) from the second flame hole (H ₂ ), and the cathode portion (T ₁ ) and the electrode portion (P ₁ )
Is smaller than the second distance (y). Thereby, the discharge from the electrode portion (P ₁ ) to the cathode portion (T ₁ ) during the discharge is ensured, and the discharge leak to the gas burner does not occur.

As a result, the discharge spark from the electrode portion (P ₁ ) to the cathode portion (T ₁ ) is generated from the region where the gas mixture having a low gas concentration is ejected to the region where the gas mixture having a high gas concentration is ejected. Since the gas passes through the proper ignition concentration range existing in the ignition discharge path, reliable ignition performance can be obtained. In this embodiment, as shown in FIG. 1, a spark plug (P) on the inner surface of the upper plate (15) is provided.
Immediately above, when forming an insertion hole for the ignition plug (P) in the upper plate (15), cut and raise the part corresponding to this insertion hole,
A protection plate (17) bent obliquely upward is provided continuously. Therefore, dew water generated on the inner surface of the burner box (1)
Even if it flows down from above (P), it will be guided to the left and right of the spark plug (P) by the protective plate (17), exposing the spark plug (P) and the upper plate (15) as a mounting part for this. The inconvenience of a short circuit caused by running water is also eliminated. Further, since the protective plate (17) for this purpose is formed at the same time as the formation of the insertion hole for the ignition plug (P), there is no waste of material, no labor for assembly is required, and the insertion hole for the ignition plug is not required. There is no displacement of the protection plate.

This configuration is also employed in the mounting portion of the other detector (S). In this embodiment, the ignition plug (P) and the electrode plate (T) are connected to the upper plate (1) constituting the front plate (1b).
Although attached to 5), as shown in FIG. 9, it may be attached to the upper part of the component wall of the box main body (1a). Also in this case, as in the case described above, the protection plate (17) can be formed by cutting and raising.

[Brief description of the drawings]

FIG. 1 is a sectional view of a water heater according to an embodiment of the present invention.

FIG. 2 is an explanatory view of an intermediate product before forming a box main body (1a).

FIG. 3 is a perspective view of a box main body (1a).

FIG. 4 is a sectional view taken along the line YY of the box main body (1a).

FIG. 5 is a plan view of a burner block.

FIG. 6 is an explanatory view of a main part of the front of the burner block.

FIG. 7 is an exploded view of the bottom of the burner box (1).

FIG. 8 is a sectional view of a flame hole of a gas burner (B ₁ ).

FIG. 9 is an explanatory view of another example of mounting a spark plug (P) and the like.

[Explanation of symbols]

(H ₁ ) ・ ・ ・ First flame hole (H ₂ ) ・ ・ ・ Second flame hole (T) ・ ・ ・ Electrode plate (B ₂ ) ・ ・ ・ Flame hole part (P) ・ ・ ・ Spark plug (P ₁ ) ・ ・ ・ Electrode part

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F23Q 3/00 102 F23C 11/00 329 F23D 14/08

Claims (1)

(57) [Claims] An ignition device for a gas burner in which first flame holes (H ₁ ) having a high gas concentration and second flame holes (H ₂ ) having a low gas concentration are alternately arranged in parallel in a flame hole portion. The cathode portion (T ₁ ) of the electrode plate (T) is placed along the outer edge of the first flame hole (H ₁ ) disposed at the edge of the first flame above the first flame hole (H ₁ ). hole _{(H 1)} a first distance from and disposed in a (x), upwards in the second burner ports inside the second burner ports of the first fire hole _{(H 1) (H 2)} (H 2) A second distance (y) from the electrode portion (P ₁ ) of the spark plug (P), the first distance (x) is smaller than the second distance (y), and the cathode portion (P). A third distance (z) between T ₁ ) and the electrode portion (P ₁ ) is smaller than the second distance (y), and the electrode portion (P ₁ ) discharges to the cathode portion (T ₁ ). Ignition equipment .