JP2547701Y2 - Forced combustion device - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The invention relates to a forced combustion device in which a crack in an insulator such as a spark plug is prevented.

(Prior Art) Conventionally, this kind of forced combustion device is capable of performing high-load combustion, and thus has been widely used for equipment such as a water heater in which miniaturization is desired.

An example will be described using a water heater. A heat exchanger is mounted on a frame. An air supply fan for forcibly supplying combustion air is provided in the frame, and a burner having a combustion chamber formed in a space above the flame port is accommodated therein. Here, when the premixed gas blows out from the flame outlet, it is ignited by spark discharge from a spark plug inserted into the combustion chamber, and further,
Secondary air gushes from the air supply plates arranged on both sides of the burner. Therefore, a short-flame flame that promotes combustion is formed, thereby heating the heat exchanger efficiently.

(Problems to be Solved by the Invention) By the way, the above-mentioned flame has a high temperature, and in addition, the outer surface has a property of fluttering in the direction of the wall plate of the combustion chamber and burning in a very close state. Therefore, the insulator of the ignition plug penetrating the wall plate is heated to a remarkably high temperature, causing excessive thermal stress and cracking. In this case, the high pressure leaks and the ignition performance is deteriorated. .

The present invention has been made to solve the above-mentioned drawbacks, and has as its object to provide a forced combustion device capable of preventing an insulator crack of an ignition plug due to thermal stress.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention is directed to a burner in which premixed gas is ejected from a flame port plate, a partition plate, and an air supply plate provided with a large number of air ejection holes. Are arranged in a vertical posture, a spark plug is provided in which an insulator penetrates one of the partition plates and an electrode tip is located immediately above the flame port plate, and the combustion chamber is surrounded. A secondary air passage, and an air chamber formed in communication with the secondary air passage,
A forced-combustion device having an air supply fan hanging down from a bottom plate forming an air chamber, wherein at least a lower part of a partition plate through which the insulator penetrates, a vent hole for discharging a part of the secondary air into the combustion chamber. And a drift plate is disposed on the flame plate at a position facing the vent hole at a slight distance.

(Operation) With the above configuration, the combustion air from the air supply fan flows into the secondary air passage via the air chamber. A part of the gas blows out from the vent hole into the combustion chamber and collides with the drift plate.
It rises after drifting. Therefore, since an air layer is interposed between the flame and the partition plate to cool the insulator, cracking of the insulator can be prevented.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS.

Reference numeral 1 denotes a frame on which the heat exchanger 2 is placed. The frame 1 is provided with an air supply fan 3 hanging down from its bottom plate. A partition plate 4 is provided on the blowout side of the air supply fan 3 to form an air chamber 5. The air supply fan 3 and the mixing pipe opening 7 of the burner 6 communicate with each other through the air chamber 5. A large number of flame ports 9 are formed in the flame port plate 8 of the burner 6, and a partition plate 10 and an air supply plate 11 are connected to each other in a vertical position above the flame port 9 to form a combustion chamber 12. In the air supply plate 11, here, bulging portions 13 formed so as to protrude outward are arranged in a horizontal direction, and further, a large number of air blowing holes 14 are formed so as to surround each bulging portion 13. . The partition plate 10 has a plurality of ventilation holes 15 formed in a lower portion, and an insulator 17 of a spark plug 16 penetrates one of the ventilation holes 15. The vent hole 15 may have any shape such as a slit or a square hole. In order to prevent the occurrence of electric discharge between the insulator 17 and the partition plate 10, the insulator 1 is so formed as to protrude somewhat into the combustion chamber 12.
At this time, the tip of the electrode 18 is located several mm above the flame plate 8. Numeral 19 denotes a drift plate provided on the flame plate 8, and its vertical surface is opposed to the vent hole 15 with a small distance. Reference numeral 20 denotes a secondary air passage formed so as to surround the combustion chamber 12 and communicates with the air chamber 5 through a large number of communication holes 21 formed in the partition plate 4.

Reference numeral 22 denotes a nozzle. In this case, when the valve rod 23 slides and opens, a gaseous gas of kerosene is ejected, and at 24, an insulator 25 is provided through the partition plate 10 similarly to the ignition plug 16. Frame rod.

 Next, the operation in the above configuration will be described.

When a hot water tap (not shown) is opened and water flows into the heat exchanger 2, the air supply fan 3 is started to feed combustion air into the air chamber 5, and a part of the air is used as primary air as the mixing pipe opening 7.
It then flows into the burner 6. Further, since the nozzle 22 is also opened, the vaporized gas is jetted into the burner 6. Accordingly, when the primary air and the vaporized gas are mixed to form a pre-mixed gas and jetted into the combustion chamber 12, it is ignited and burned by a spark discharge formed between the tip of the electrode 18 and the flame port plate 8. Then, at the same time when the flame rod 24 detects the flame, the spark discharge stops.
On the other hand, the remaining combustion air in the air chamber 5 reaches the secondary air passage 20 through the communication hole 21 as secondary air, and gushes it from the air ejection hole 14 so as to be substantially orthogonal to the flame. Accordingly, combustion is promoted, and the heat exchanger 2 is heated by the high-temperature flame having a short fire foot, so that the inflow water becomes hot water and flows out.

In the above combustion, since the secondary air passage 20 surrounds the combustion chamber 12, a part of the secondary air also blows out from the ventilation hole 15 into the combustion chamber 12. The jet air collides with and drifts with the drift plate 19 immediately after the jet, and rises along the partition plate 10. Here, the upward flow flows in parallel with the direction of extension of the flame and is hardly used for combustion, so that an air layer is formed between the flame and the partition plate 10. Therefore, since the insulators 17 and 25 which receive the heat rays from the flame are efficiently cooled by the air layer, the thermal stress is small and the insulators can be completely prevented from being cracked.

In addition, since the partition plate 10 is also cooled by the air layer and is not deformed, there is no gap in the portion connected to the air supply plate 11 where the secondary air leaks to deteriorate combustion.

Further, the drift plate 19, as shown in FIG. 4, keeps the base of the flame formed adjacent thereto, so that the lifting combustion is difficult and the combustion noise is reduced.

In the above-described embodiment, kerosene is used as the fuel. However, it goes without saying that the present invention can be easily applied to fuels such as city gas and LP gas by slightly changing the fuel gas ejection mechanism.

(Effects of the Invention) As described above, the forced combustion device of the present invention has a ventilation hole for discharging a part of the secondary air into the combustion chamber below the partition plate through which an insulator such as a spark plug penetrates. Since the drift plate is disposed on the flame plate at a position facing the vent hole at a small distance, an air layer is interposed between the flame and the partition plate to efficiently cool the insulator. For this reason, the insulator can be completely prevented from being cracked, and the drift plate has many excellent effects, such as maintaining the base of the adjacent flame, suppressing lifting combustion and reducing combustion noise.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view of a forced combustion apparatus according to the present invention, FIG. 2 is a transverse sectional view thereof, FIG. 3 is a plan view of essential parts, and FIG. FIG. 3 ... air supply fan, 5 ... air chamber, 6 ... burner,
10 ... screen plate, 12 ... combustion chamber, 15 ... vent hole, 16 ... spark plug, 19 ... drift plate, 20 ... secondary air passage.

Claims (1)

(57) [Scope of request for utility model registration] 1. A burner from which a premixed gas is blown out from a flame port plate.
A partition plate, a combustion chamber formed by connecting each of the air supply plates with a number of air ejection holes in a vertical posture, an insulator penetrates one of the partition plates, and the electrode tip is a flame port A spark plug located immediately above the plate, a secondary air passage formed to surround the combustion chamber, an air chamber formed in communication with the secondary air passage, and a droop to a bottom plate forming the air chamber. In the forced combustion device provided with an air supply fan provided in the above manner, at least a lower part of a partition plate through which the insulator penetrates, is provided with a ventilation hole for discharging a part of the secondary air into the combustion chamber, A forced-combustion device, wherein a deflector plate is disposed on a flame port plate at a position opposed to a small distance.