JP2018128199A - Manifold for gas supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable breakthrough of water sealing at a nozzle part of a manifold for gas supply, in a state of suppressing pressure of fuel gas applied to the nozzle part.SOLUTION: At a tip of a nozzle part 31 projecting toward a burner of a combustor, a flat surface 31b is formed, and on the flat surface 31b, a nozzle hole 31a for jetting out fuel gas is protrusively provided. A value of an area ratio obtained by dividing an area of the flat surface 31b by an opening area of a nozzle hole 31a is set to be equal to or less than 10. Consequently, with pressure of fuel gas controlled to pressure (about 0.8 kPa) not causing explosive ignition at the burner, a maximum amount of water droplets adhering to the flat surface 31b can be controlled so that the water droplets are blown out with jetting force of fuel gas. As the result, with explosive ignition prevented at the burner, water sealing at the nozzle part 31 can be broken through.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a gas supply manifold that has a plurality of nozzle portions protruding toward a plurality of burners of a combustion apparatus and distributes fuel gas to the plurality of nozzle portions.

  Some combustion devices mounted on a water heater or the like have a plurality of burners, and the amount of generated heat (hot water supply capacity) can be changed by switching the number of burners for burning fuel gas. Such a combustion apparatus has a plurality of nozzle portions projecting toward a plurality of burners, and a gas supply manifold that distributes fuel gas to the plurality of nozzle portions. A flat surface is formed at the tip of the nozzle portion of the gas supply manifold, and fuel gas is ejected from a nozzle hole drilled in the flat surface toward the burner (for example, Patent Documents). 1).

  In such a gas supply manifold, condensation may occur due to the backflow of warm and humid combustion exhaust gas after the fire extinguishing in the burner, and in particular, condensation occurs on the flat surface of the nozzle portion and the nozzle hole is blocked by water droplets. When a water seal occurs, the fuel gas does not blow out at the next ignition, which causes an ignition failure. Therefore, in order to blow the water droplets that block the nozzle hole with the pressure of the fuel gas and break through the water seal, the pressure of the fuel gas applied to the nozzle portion at the time of ignition is made higher than the pressure of the fuel gas necessary for combustion. It has been broken.

JP 2004-197971 A

  However, when the pressure of the fuel gas at the time of ignition becomes high, excessive fuel gas is ejected from the nozzle hole, so that there is a problem that a loud noise may be generated due to explosive ignition by the burner.

  The present invention has been made in response to the above-described problems in the prior art, and is a gas supply manifold capable of breaking through the water seal of the nozzle portion while suppressing the pressure of fuel gas applied to the nozzle portion during ignition. The purpose is to provide.

In order to solve the above-described problems, the first gas supply manifold of the present invention employs the following configuration. That is,
In a gas supply manifold that has a plurality of nozzle portions protruding toward a plurality of burners of a combustion device and distributes fuel gas to the plurality of nozzle portions,
The nozzle portion has a flat surface formed at the tip, and a nozzle hole through which the fuel gas is ejected toward the burner is formed in the flat surface.
The area ratio value obtained by dividing the area of the flat surface by the opening area of the nozzle hole is set to 10 or less.

  The larger the area of the flat surface, the larger the maximum amount of water droplets that can adhere to the flat surface. Therefore, in order to break through the water seal with the fuel gas jet power, it is necessary to increase the pressure of the fuel gas. In addition, since the fuel gas jet power is proportional to the fuel gas pressure and the opening area of the nozzle hole, in order to ensure the jet power, the fuel gas pressure needs to be increased as the nozzle hole opening area decreases. There is. In the first gas supply manifold of the present invention, the area of the flat surface of the nozzle part is set to be small so that the value of the area ratio is 10 or less in relation to the opening area of the nozzle part. The maximum amount of water droplets adhering to the flat surface can be kept to a level that can be blown off by the fuel gas jet power while suppressing the pressure of the gas to a pressure (about 0.8 kPa) that does not cause explosive ignition with the burner. As a result, it is possible to break through the water seal of the nozzle part while preventing explosive ignition in the burner.

In order to solve the above-mentioned problem, the second gas supply manifold of the present invention employs the following configuration. That is,
In a gas supply manifold that has a plurality of nozzle portions protruding toward a plurality of burners of a combustion device and distributes fuel gas to the plurality of nozzle portions,
The nozzle portion has a flat surface formed at the tip, and a nozzle hole through which the fuel gas is ejected toward the burner is formed in the flat surface.
The nozzle portion is connected to the flat surface, and is provided with a guide portion that guides water droplets adhering to the flat surface to the outer periphery of the nozzle portion.

  In such a second gas supply manifold of the present invention, the amount of water droplets blocking the nozzle holes on the flat surface can be reduced by guiding the water droplets adhering to the flat surface to the outer periphery of the nozzle portion by the guiding portion. Therefore, it becomes possible to break through the water seal of the nozzle portion with the jet power of the fuel gas while suppressing the pressure of the fuel gas applied to the nozzle portion.

  In the above-described second gas supply manifold of the present invention, the nozzle portion protrudes in a substantially horizontal direction, and the flat surface is formed substantially perpendicular to the protrusion direction of the nozzle portion. You may connect a guidance part to the side.

  In this way, when the amount of water droplets adhering to the flat surface increases, the water droplets on the flat surface move to the lower guiding portion by the action of gravity, so that the water droplets can be guided to the outer periphery of the nozzle portion.

  Further, the guide part of the above-described second gas supply manifold of the present invention may be a ridge extending from the front end of the nozzle part toward the rear end in a state of protruding in the radial direction of the nozzle part. .

  If it does in this way, the water droplet which moved to the downward protrusion from the flat surface by the action of gravity will flow along the protrusion. The flow once generated pulls the water droplets on the flat surface, whereby the water droplets can be guided from the flat surface to the outer periphery of the nozzle portion.

  Further, the guide part of the above-described second gas supply manifold of the present invention may be a groove extending from the front end to the rear end of the nozzle part in a state of being recessed in the outer peripheral surface of the nozzle part.

  In this way, since the water droplets adhering to the flat surface try to penetrate into the groove by capillary action, the water droplet can be guided from the flat surface to the outer periphery of the nozzle portion through the groove.

It is explanatory drawing which showed the structure of the combustion apparatus 10 by making the water heater 1 into an example. It is explanatory drawing which showed the structure of the manifold 30 and the burner 20 of a present Example. It is explanatory drawing which expanded and showed the shape of the nozzle part 31 of 1st Example. It is explanatory drawing which showed the state in which the water seal produced in the nozzle part. 5 is a graph showing the relationship between the shape of the tip of the nozzle part 31 and the pressure of fuel gas that can break through the water seal of the nozzle part 31. It is sectional drawing which shows the example which made the shape of the front-end | tip of the nozzle part 31 a hemispherical surface or a conical surface. It is explanatory drawing which expanded and showed the shape of the nozzle part 31 of 2nd Example. It is explanatory drawing which expanded and showed the shape of the nozzle part 31 of 3rd Example.

  FIG. 1 is an explanatory diagram showing the configuration of a combustion apparatus 10 by taking the water heater 1 as an example. As shown in the figure, the combustion apparatus 10 of the present embodiment has a plurality of (15 in the illustrated example) burners 20 accommodated in the combustion chamber 11. Further, the combustion chamber 11 includes a manifold 30 that distributes fuel gas to a plurality of nozzle portions 31 protruding toward the burner 20, a combustion fan 12 that supplies combustion air to the burner 20 from below, and a high voltage. A spark plug 13 and the like are provided to discharge a spark by the discharge. The manifold 30 of this embodiment corresponds to a “gas supply manifold” of the present invention.

  The gas passage 40 for supplying the fuel gas to the manifold 30 includes a main valve 41 for opening and closing the gas passage 40, and a proportional valve 42 for adjusting the flow rate of the fuel gas supplied to the manifold 30 on the downstream side of the main valve 41. Is provided. Further, in the illustrated example, in correspondence with the fact that a plurality of (15) burners 20 are divided into three burner groups, the gas passage 40 is branched into three on the downstream side of the proportional valve 42, A first switching valve 43a that opens and closes a branch corresponding to a first burner group constituted by three burners 20, and a second switching that opens and closes a branch corresponding to a second burner group constituted by five burners 20. The valve 43b and the 3rd switching valve 43c which opens and closes the branch corresponding to the 3rd burner group comprised by the seven burners 20 are provided.

  In the combustion apparatus 10, the amount of generated heat (hot water supply capacity) can be switched depending on which burner group burns fuel gas by controlling the opening and closing of the three switching valves 43a to 43c. For example, when the amount of heat required is the minimum, only the first switching valve 43a is opened. On the other hand, when the required amount of heat is maximum, all the three switching valves 43a to 43c are opened. When the amount of heat during that time is required, one or two of the three switching valves 43a to 43c are appropriately selected and opened.

  A heat exchanger 50 is provided above the combustion chamber 11. A water supply passage 51 is connected to one end of the heat exchanger 50, and a hot water supply passage 52 is connected to the other end of the heat exchanger 50. The clean water supplied through the water supply passage 51 is heated by heat exchange with the combustion exhaust of the burner 20 in the heat exchanger 50 and then flows into the hot water supply passage 52 as hot water. The water supply passage 51 is provided with a water flow sensor 53 that detects the flow of water in the water supply passage 51, and the user of the water heater 1 opens the currant 54 provided in the hot water supply passage 52. When water is supplied to 50, the water flow sensor 53 detects the flow of water, and combustion is started in the burner 20.

  Further, an exhaust port 60 is provided above the heat exchanger 50. The combustion exhaust from the burner 20 is sent upward by the blow of the combustion fan 12 and passes through the heat exchanger 50 and is discharged from the exhaust port 60 to the outside of the water heater 1.

  FIG. 2 is an explanatory view showing the structure of the manifold 30 and the burner 20 of this embodiment. First, FIG. 2A shows a perspective view of the manifold 30 viewed from the burner 20 side. The manifold 30 of the present embodiment is configured by combining a plate-like main body 32 formed by die casting using an aluminum alloy and a lid plate 33 formed by sheet metal. The main body 32 is provided with the same number of sets (15 sets in the present embodiment) as the burner 20 in a pair of upper and lower nozzle portions 31 protruding from the surface opposite to the surface covered with the cover plate 33 toward the burner 20. Yes. At the tips of these nozzle portions 31, nozzle holes 31a are opened. The detailed shape of the nozzle portion 31 will be described later with reference to another drawing. Further, below the nozzle portion 31, the above-described three switching valves 43a to 43c that open and close the three branches of the gas passage 40 are provided.

  Moreover, the burner 20 of a present Example is comprised combining a pair of plate-shaped member formed with the sheet metal, and has a flat shape. The burner 20 is provided with a plurality of flame ports 21 at the upper end and a pair of upper and lower gas inlets 22 at the end on the manifold 30 side, and is formed between the pair of plate-like members. The gas inlet 22 and the flame outlet 21 are connected by the mixing passage 23. In a state where the manifold 30 and the burner 20 are installed in the combustion apparatus 10, the pair of upper and lower nozzle portions 31 of the manifold 30 and the pair of upper and lower gas inlets 22 of the burner 20 are arranged to face each other. In FIG. 2A, only one burner 20 is illustrated, but the burner 20 is provided in each pair of the upper and lower pair of nozzle portions 31.

  FIG. 2B shows a cross-sectional view of the manifold 30 cut along a plane parallel to the burner 20. The main body 32 and the lid plate 33 of the manifold 30 are kept airtight by interposing a packing 34 formed of an elastic member such as rubber, and are fixed with screws or the like. A distribution passage 35 is formed between the main body 32 and the cover plate 33 thus combined. In the manifold 30 of this embodiment, three distribution passages 35 are formed corresponding to the three burner groups described above. ing. Each distribution passage 35 communicates with the gas passage 40 via the gas flow hole 36, and the three switching valves 43 a to 43 c described above open and close the corresponding gas flow hole 36. Therefore, the distribution passage 35 for supplying the fuel gas can be switched by controlling the opening and closing of the three switching valves 43a to 43c.

  The plurality of nozzle portions 31 are in communication with the distribution passage 35, and when the switching valve 43 is opened, the fuel gas flowing in from the gas circulation holes 36 is supplied to the nozzle portion 31 through the distribution passage 35. The fuel gas ejected from the nozzle portion 31 flows into the gas inlet 22 of the burner 20 while sucking combustion air from the surroundings by the ejector effect, and the fuel gas passing through the mixing passage 23 and the combustion air are mixed. The mixed gas is burned at the flame port 21 at the upper end of the burner 20.

  FIG. 3 is an explanatory view showing an enlarged shape of the nozzle portion 31 of the first embodiment. FIG. 3A shows a perspective view of the nozzle portion 31 as viewed from the burner 20 side, and FIG. 3B shows the nozzle portion 31 cut along a plane including the central axis of the nozzle portion 31. A cross-sectional view is shown. The nozzle portion 31 protrudes in a substantially horizontal direction toward the burner 20 in a state where the manifold 30 is installed in the combustion device 10, and the outer peripheral surface of the nozzle portion 31 decreases in outer diameter toward the tip. It is formed in a taper shape. Further, the inner peripheral surface of the nozzle portion 31 through which the fuel gas flows is also formed in a tapered shape whose inner diameter decreases toward the tip. A flat surface 31b is formed at the tip of the nozzle portion 31 substantially perpendicular to the protruding direction of the nozzle portion 31, and the nozzle hole 31a extends in the protruding direction of the nozzle portion 31 on the flat surface 31b. It is provided through.

  The main body 32 of the manifold 30 of the present embodiment is formed by die casting as described above, and the shape of the outer peripheral surface and inner peripheral surface of the nozzle portion 31 is also formed integrally with the main body 32 by die casting. However, since the nozzle hole 31a from which the fuel gas is ejected is required to be precise, it is formed later by drilling with a drill or the like. In this case, by making the tip of the nozzle portion 31 in which the nozzle hole 31a is drilled a flat surface 31b, drilling is easier than when the tip of the nozzle portion 31 is a spherical surface or a conical surface, and the nozzle hole The positional deviation of 31a can be reduced.

  In the manifold 30 having such a nozzle portion 31, dew condensation may occur when the warm and humid combustion exhaust gas flows back from the heat exchanger 50 side to the manifold 30 side after the fire extinguishing in the burner 20. In particular, when a water seal occurs in which condensation occurs on the flat surface 31b of the nozzle portion 31 and the nozzle hole 31a is blocked by water droplets, the corresponding burner 20 is prevented from ejecting fuel gas from the nozzle hole 31a at the next ignition. Then, it becomes an ignition failure.

  FIG. 4 is an explanatory view showing a state in which a water seal has occurred in the nozzle portion 31. In the drawing, a cross section obtained by cutting the nozzle portion 31 along a plane including the central axis of the nozzle portion 31 is shown. When dew condensation occurs on the flat surface 31b of the nozzle portion 31, water droplets adhering to the flat surface 31b become hemispherical due to surface tension to cover the nozzle holes 31a, and some of the water droplets penetrate into the nozzle holes 31a.

  At this time, if the amount of water droplets adhering to the flat surface 31b is small, it is possible to blow through the water seal by blowing off the water droplets with the jet power of the fuel gas ejected from the nozzle hole 31a when the burner 20 is ignited. However, as the amount of water drops increases, it becomes difficult to break through the water seal, and as the area of the flat surface 31b increases, the maximum amount of water drops that can adhere to the flat surface 31b also increases. It is necessary to increase the fuel gas jet power. Therefore, in the combustion apparatus 10 equipped with the manifold 30 of the conventional example, when the burner 20 is ignited, the valve opening of the proportional valve 42 is increased to increase the flow rate of the fuel gas supplied to the manifold 30 to be applied to the nozzle portion 31. Increasing the pressure of the fuel gas has been performed. However, when the pressure of the fuel gas at the time of ignition becomes high, a loud noise may be generated due to explosive ignition by the burner 20.

  Moreover, since the jet power of the fuel gas ejected from the nozzle hole 31a is proportional to the pressure of the fuel gas applied to the nozzle portion 31 and the opening area of the nozzle hole 31a, in order to ensure the fuel gas jet power, It is necessary to increase the pressure of the fuel gas as the opening area of the nozzle hole 31a is smaller.

  FIG. 5 is a graph showing the relationship between the shape of the tip of the nozzle portion 31 and the pressure of the fuel gas that can break through the water seal of the nozzle portion 31. In the graph of FIG. 5, the pressure of the fuel gas in the nozzle part 31 is taken on the horizontal axis, and the area ratio value obtained by dividing the area of the flat surface 31 b of the nozzle part 31 by the opening area of the nozzle hole 31 a is taken on the vertical axis. When the area of the flat surface 31b is varied while the opening area of the nozzle hole 31a is fixed, the fuel gas necessary for breaking through the water seal at the nozzle portion 31 to which the maximum amount of water droplets covering the entire flat surface 31b has adhered is attached. The result of experimentally determining the pressure is shown. As shown by the curve in the figure, as the area ratio value increases, the fuel gas pressure required to break through the water seal increases, and in the area to the lower right of the curve, the first pressurization is reliable. In contrast, the water seal can be broken through, but in the region on the upper left side of the curve, the water seal may not be broken through, and it is necessary to repeat pressurization (repeat the ignition process).

  For example, in the case of the conventional manifold 30 in which the diameter of the flat surface 31b of the nozzle portion 31 is 4.5 mm and the diameter of the nozzle hole 31a is 1.05 mm, the area ratio value is 18.4. In order to reliably break through the water seal with the first pressurization at the time of ignition of 20, it is necessary to set the pressure of the fuel gas applied to the nozzle portion 31 to be higher than 1.1 kPa. A loud noise may be generated due to explosive ignition caused by the supply. Experience has shown that such explosive ignition can be prevented by reducing the pressure of the fuel gas to 0.8 kPa.

  Therefore, in the manifold 30 of the first embodiment, the area of the flat surface 31b of the nozzle portion 31 is set to be small so that the area ratio value is 10 or less in relation to the opening area of the nozzle hole 31a. As a result, the maximum amount of water droplets adhering to the flat surface 31b can be limited to such an extent that the fuel gas can be blown off while the pressure of the fuel gas is suppressed to 0.8 kPa. Therefore, it is possible to break through the water seal of the nozzle portion 31 without causing explosive ignition by the burner 20.

  Further, as the area of the flat surface 31b is reduced, the maximum amount of water droplets adhering to the flat surface 31b is reduced and the water seal is easily broken. Therefore, the outer edge of the nozzle hole 31a is substantially eliminated by eliminating the flat surface 31b. May be a hemispherical surface as shown in FIG. 6 (a) or a conical surface as shown in FIG. 6 (b). In this case, it can be considered that the nozzle hole 31a is formed on the entire flat surface 31b, and the area of the flat surface 31b matches the opening area of the nozzle hole 31a, so the value of the area ratio is 1. In this way, there is no room for water droplets to adhere to the tip of the nozzle portion 31 so as to cover the nozzle hole 31a, so that the fuel gas is ejected by water sealing regardless of the pressure of the fuel gas applied to the nozzle portion 31. It can prevent itself from being disturbed.

  Further, as shown in FIG. 5, not only when the opening area of the nozzle hole 31a is fixed and the area of the flat surface 31b is changed, but the illustration is omitted, the area of the flat surface 31b is fixed. Even when the opening areas of the nozzle holes 31a are made different, the same tendency as in FIG. 5 is observed in the relationship between the area ratio value and the pressure of the fuel gas necessary for breaking the water seal of the nozzle portion 31. Therefore, the opening area of the nozzle hole 31a may be set large so that the value of the area ratio is 10 or less in relation to the area of the flat surface 31b. As a result, it is possible to ensure the fuel gas jetting power that blows away the maximum amount of water droplets adhering to the flat surface 31b while suppressing the pressure of the fuel gas to 0.8 kPa, so that it is possible to break through the water seal of the nozzle portion 31. Become.

  FIG. 7 is an explanatory diagram showing an enlarged shape of the nozzle portion 31 of the second embodiment. In the figure, the state which looked at the nozzle part 31 from the burner 20 side is represented with the perspective view. Similar to the first embodiment described above, the nozzle portion 31 of the second embodiment is also protruded in a substantially horizontal direction toward the burner 20 with the manifold 30 installed in the combustion device 10. A nozzle hole 31a is formed in a flat surface 31b substantially perpendicular to the installation direction. Further, as shown in the figure, on the lower end side of the nozzle portion 31 of the second embodiment, a protrusion 31d extending in the generatrix direction is provided in a state protruding from the outer peripheral surface formed in the conical surface. The protrusion 31d is connected to the flat surface 31b at the end surface 31e on the tip side of the nozzle portion 31, and the end surface 31e is disposed on the same plane as the flat surface 31b.

  In the nozzle portion 31 of the second embodiment, when the amount of water droplets adhering to the flat surface 31b increases, the water droplets that have moved from the flat surface 31b to the lower end surface 31e due to the action of gravity travel along the ridge 31d. It flows. The flow once generated pulls the water droplets on the flat surface 31 b, whereby the water droplets are guided from the flat surface 31 b to the outer periphery of the nozzle portion 31. The protrusion 31d of the second embodiment corresponds to the “guidance part” of the present invention.

  As described above, in the manifold 30 of the second embodiment, the protrusion 31d is provided on the nozzle portion 31, and water droplets adhering to the flat surface 31b are guided to the outer periphery of the nozzle portion 31 by the protrusion 31d. Therefore, it is possible to reduce the amount of water droplets that block the nozzle hole 31a, so that it is possible to break through the water seal of the nozzle portion 31 with the fuel gas jet output while suppressing the pressure of the fuel gas applied to the nozzle portion 31 at the time of ignition. Become.

  FIG. 8 is an explanatory view showing an enlarged shape of the nozzle portion 31 of the third embodiment. In the figure, the state which looked at the nozzle part 31 from the burner 20 side is represented with the perspective view. Similar to the first embodiment described above, the nozzle portion 31 of the third embodiment is also protruded in a substantially horizontal direction toward the burner 20 with the manifold 30 installed in the combustion device 10. A nozzle hole 31a is formed in a flat surface 31b substantially perpendicular to the installation direction. Further, as shown in the drawing, a groove 31g extending in the generatrix direction is provided on the lower end side of the nozzle portion 31 of the third embodiment while being recessed in the outer peripheral surface formed in the conical surface. The groove 31g is connected to the flat surface 31b.

  In such a nozzle part 31 of the third embodiment, water droplets adhering to the flat surface 31b try to penetrate into the groove 31g by capillary action. Therefore, water droplets are guided from the flat surface 31b to the outer periphery of the nozzle portion 31 through the groove 31g. Incidentally, the groove 31g of the third embodiment corresponds to the “guidance part” of the present invention.

  As described above, in the manifold 30 of the third embodiment, the groove 31g is provided in the nozzle portion 31, and water droplets adhering to the flat surface 31b are guided to the outer periphery of the nozzle portion 31 through the groove 31g. Since the amount of water droplets blocking the hole 31a can be reduced, it is possible to break through the water seal of the nozzle portion 31 with the fuel gas spray output while suppressing the pressure of the fuel gas applied to the nozzle portion 31 during ignition.

  In the manifold 30 of the third embodiment, the groove 31g is provided on the lower end side of the nozzle portion 31, but the position where the groove 31g is provided is not limited to the lower end side of the nozzle portion 31. For example, even if the groove 31g is provided on either the left or right side of the nozzle portion 31, if the groove 31g is connected to the flat surface 31b, water droplets on the flat surface 31b can be guided to the outer periphery of the nozzle portion 31 through the groove 31g by capillary action. it can. However, if the groove 31g is provided on the lower end side of the nozzle portion 31 as in the third embodiment, the action of gravity is also added, so that the flat surface is compared with the case where the groove 31g is provided on either the left or right side of the nozzle portion 31. The effect of guiding the water droplets 31b to the outer periphery of the nozzle portion 31 can be enhanced.

  Although the manifold 30 of various embodiments has been described above, the present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the gist thereof.

  For example, the protrusion of the second embodiment is applied to the nozzle portion 31 set so that the area ratio value obtained by dividing the area of the flat surface 31b by the opening area of the nozzle hole 31a as in the first embodiment is 10 or less. The groove 31d or the groove 31g of the third embodiment may be provided. In this way, in addition to the effects of the first embodiment described above, the effects of the second embodiment or the third embodiment can also be obtained, so that the water seal of the nozzle portion 31 can be more reliably broken through. It becomes possible.

  In the second embodiment, the protrusion 31d is provided on the nozzle portion 31 formed in a conical shape. However, the shape of the nozzle portion 31 is not limited to the conical shape, and is a pyramid shape such as a triangular pyramid or a quadrangular pyramid. May be. In the case of the pyramidal nozzle portion 31, the ridge line extending from the front end of the nozzle portion 31 toward the rear end in a state of protruding in the radial direction of the nozzle portion 31 corresponds to the protrusion 31 d of the second embodiment, and the guide portion Function as.

  In the third embodiment, the groove 31g is provided in the nozzle portion 31 formed in a conical shape. However, the shape of the nozzle portion 31 is not limited to the conical shape, and is a pyramid shape such as a triangular pyramid or a quadrangular pyramid. Also good. In the case of the pyramid-shaped nozzle portion 31, a groove 31g extending from the front end to the rear end of the nozzle portion 31 in a state of being depressed on any side surface of the pyramid may be provided.

DESCRIPTION OF SYMBOLS 1 ... Hot water heater, 10 ... Combustion apparatus, 11 ... Combustion chamber,
12 ... Combustion fan, 13 ... Spark plug, 20 ... Burner,
21 ... Flame port, 22 ... Gas inlet, 23 ... Mixing passage,
30 ... Manifold, 31 ... Nozzle part, 31a ... Nozzle hole,
31b ... flat surface, 31d ... ridge, 31e ... end face,
31g ... groove, 32 ... main body, 33 ... lid plate,
34 ... packing, 35 ... distribution passage, 36 ... gas flow hole,
40 ... gas passage, 41 ... main valve, 42 ... proportional valve,
43 ... switching valve, 50 ... heat exchanger, 51 ... water supply passage,
52 ... Hot water supply passage, 53 ... Water flow sensor, 54 ... Karan,
60: Exhaust port.

Claims (5)

In a gas supply manifold that has a plurality of nozzle portions protruding toward a plurality of burners of a combustion device and distributes fuel gas to the plurality of nozzle portions,
The nozzle portion has a flat surface formed at the tip, and a nozzle hole through which the fuel gas is ejected toward the burner is formed in the flat surface.
A gas supply manifold, wherein an area ratio value obtained by dividing an area of the flat surface by an opening area of the nozzle hole is set to 10 or less. In a gas supply manifold that has a plurality of nozzle portions protruding toward a plurality of burners of a combustion device and distributes fuel gas to the plurality of nozzle portions,
The nozzle portion has a flat surface formed at the tip, and a nozzle hole through which the fuel gas is ejected toward the burner is formed in the flat surface.
The gas supply manifold is characterized in that the nozzle portion is provided with a guide portion that is connected to the flat surface and guides water droplets adhering to the flat surface to the outer periphery of the nozzle portion. The gas supply manifold according to claim 2,
The nozzle portion protrudes in a substantially horizontal direction, and the flat surface is formed substantially perpendicular to the protruding direction of the nozzle portion,
The gas supply manifold, wherein the guide portion is connected to a lower end side of the flat surface. The manifold for gas supply according to claim 3,
The gas supply manifold according to claim 1, wherein the guide portion is a ridge extending from the front end of the nozzle portion toward the rear end in a state of protruding in the radial direction of the nozzle portion. In the manifold for gas supply according to claim 2 or 3,
The gas supply manifold, wherein the guide portion is a groove extending from the front end to the rear end of the nozzle portion in a state of being recessed in the outer peripheral surface of the nozzle portion.

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