JPH0531486Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to improving the durability of the fixing fittings of a forced air gas combustion device (combustion plate burner).

[Prior Art] Water heaters, bathtubs, and other water heaters use a heat exchanger in which both ends of plate fins are welded to the inner wall of a combustion box, the interior of which is a combustion chamber. A boiler usually has a gas burner fixed with a fixture below a heat exchanger. Conventionally, in this water heater, there was little risk that the fixing fittings would be exposed to flames, and therefore there was little need to consider heat resistance and durability.

[Problems to be solved by the invention] However, in recent years, in order to make equipment more compact, there has been a demand for water heaters that perform high-load combustion using forced-air burners that forcefully blow air using blowers. In this case, the fixing fitting usually has a part exposed inside the combustion chamber, and the exposed part is exposed to the flame as the flame expands due to high-load combustion and heats up to 1500℃.
Even when heat-resistant metals such as stainless steel are used, sufficient durability cannot be achieved due to the relatively high temperatures. In particular, when using a combustion plate burner made of a heat-resistant material board with many small holes for complete combustion using only primary air, the elongation of the flame becomes large and the combustion plate itself becomes hot, so it must be fixed. The durability of the metal fittings becomes an issue.

An object of the present invention is to provide a burner fixing structure that provides redundant durability of the holding fittings even in water heaters that perform such high-load combustion.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a mixing box that has a flange around the upper end and forcibly mixes fuel gas and air, and a flange around the lower end of the mixing box. a combustion box connected to the mixing box with a flange attached to the flange of the mixing box; a combustion box located on the combustion box side;
A combustion plate made of refractory material with many small holes, a locking plate portion that locks the top surface of the combustion plate, and a side plate portion whose inner wall is in close contact with the side surface of the combustion plate and whose outer wall is in close contact with the inner wall of the combustion box. , a fixing fitting having a flange portion extending outward from the lower end of the side plate portion and sandwiched by the flange; and a group of fins disposed in contact with an inner wall of the combustion box, and provided above the combustion plate. A configuration with a heat exchanger was adopted.

[Operation and effect of the invention] The side plate of the fixing metal fitting that fixes the combustion plate is in close contact with the inner wall surface of the combustion box, and even if the heat of the combustion plate is transferred to the fixing metal fitting, the combustion box is not fixed. Since the heat is quickly transmitted to the fins of the heat exchanger through the heat exchanger, the fixing metal fittings do not become extremely hot and can be used redundantly.

[Example] Figures 1 to 3 show an instantaneous gas water heater using the forced air burner of the present invention.

This water boiler is an all-primary air combustion type that completely burns only with primary air and a combustion box 10 whose inside is a combustion chamber. A heat exchanger 2 comprising a plate fin group 21 and a water conduit 22 arranged on the upper part of the combustion box 10 and having both ends welded to the inner wall of the combustion box; It includes a water heater case 3 which is housed and has an outside air inlet 31 provided at the lower part of the side plate, and a control device 5 for the burner 1.

The combustion box 10 has a rectangular cross section, has an exhaust port 10A connected to the exhaust pipe 11 at the upper end, is open at the lower end, and has a mixing box 14 inside which is a mixing chamber 1A for fuel gas and air. It is provided to close the bottom opening. The flange 12 provided around the upper end of the mixing box 14 is provided with a group of small holes, for example, in a matrix, consisting of small holes penetrating the front and back sides, and is made of a fire-resistant insulating material such as an electrically insulating ceramic sintered body. The prepared combustion plate 4 is placed thereon, and the mixing box 14 is equipped with a blower 13 for supplying air.
and a gas supply pipe 17 having an injection port 15 are attached near the outlet of the blower 13 to constitute the burner 1.

The small crater group of the combustion plate 4 consists of various small holes 4a, 4b, 4c, etc. whose ventilation resistance is varied by means such as providing a difference in cross-sectional area, and the frequency of the flame generated at each small crater is adjusted. Appropriately dispersed combustion box 10
Alternatively, generation of noise due to resonance with the exhaust stack 11 is prevented.

As shown in FIG. 3, in this embodiment, the combustion plate 4 is fixed by being formed separately from the combustion plate 4 and having a "shaped cross section".
A peripheral edge 4A of the upper surface of the combustion plate 4 and an outer peripheral side surface 4
A refractory frame 43 made of ceramic that holds B is fitted onto the combustion plate 4, and a side plate portion 45A formed of stainless steel sheet metal and tightly fitted onto the outer peripheral side plate of the refractory frame 43; The fireproof frame 45 is constructed of a locking plate part 45B extending inward from the upper end of the fireproof frame 45A and locking the upper surface of the fireproof frame 43, and a flange 45C extending outward from the lower end of the side plate part 45A. The upper surface and side surfaces of the frame 43 are held, and the side plate portion 45A is fitted to the lower end portion of the combustion box 10, and the flange 45C
is a flange 1 provided at the lower end of the combustion box 10.
It is sandwiched between 0B and the flange 12 of the mixing box 14 and fastened with bolts 19. Although the refractory frame 43 may be formed integrally with the combustion plate 4, it is preferable to form it separately as in this embodiment in order to improve thermal shock resistance.

The control device 5 includes a flame rod 6 consisting of a pair of electrodes provided on the upper surface of the combustion plate 4 to detect the presence or absence of a flame in the burner 1, a safety (electromagnetic) valve 51 provided in the gas supply pipe 17, and The safety valve 51, the flow rate control valve 53, the two-pole sparkers 55, 57, which are igniters provided on the upper surface of the combustion plate 4, and the two-pole sparkers 55, 57, which are igniters provided on the upper surface of the combustion plate 4, are activated in accordance with the operation of the operating means (not shown). Parker 55,
57 and the motor M of the blower 13, and a control circuit 50 that generates an output that automatically closes the safety valve 51 when the flame rod 6 detects a misfire or ignition error.

In this water heater, the flame goes around during high-load combustion in the burner 1, and the locking plate part 45B of the fixing metal fitting 45 is exposed to the flame, and the inner surface 43A of the fireproof frame 43 also becomes red hot, but the side plate part 45A→ Since heat is transferred smoothly in the order of combustion box 10 → plate fin group 21 → water conduit pipe 22 of heat exchanger 2, the locking plate portion 45B does not reach a very high temperature and has a sufficiently long durability for practical use. can get.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of a forced air instantaneous gas water heater, FIG. 2 is a perspective view of its main parts, and FIG. 3 is a perspective view of combustion plate fixing means. In the diagram, 1... Forced air gas combustion device (forced air burner), 2... Heat exchanger, 4... Combustion plate, 4
a, 4b, 4c...Small hole, 10...Combustion box, 10
B, 12...flange, 14...mixing box, 21...
...Plate fin group (fin group), 43... Fireproof frame, 45... Frame-shaped fixing metal fitting (fixing metal fitting), 45A
... Side plate part, 45B... Locking plate part, 45C... Flange (flange part).

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A mixing box with a flange around the upper end for forcibly mixing fuel gas and air, a flange around the lower end, and this flange attached to the flange of the mixing box. A combustion box fixed to the mixing box, a combustion plate made of a fireproof material located on the side of the combustion box and provided with many small holes, a locking plate portion that locks the top surface of the combustion plate, and an inner wall. a side plate portion that is in close contact with the side surface of the combustion plate and whose outer wall is in close contact with the inner wall of the combustion box; a fixing fitting having a flange portion that extends outward from a lower end of the side plate portion and is held by the flange; and an inner wall of the combustion box. A water heater using a forced air burner, comprising a group of fins arranged in contact with the combustion plate, and a heat exchanger provided above the combustion plate. 2. A water boiler using a forced air burner according to claim 1 of the registered utility model, in which a fireproof frame made of ceramic is interposed between the combustion plate and the fixing metal fittings.