JPH0216108Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Purpose of the invention] (Industrial application field) This invention relates to the air intake structure of a total primary premix burner, and it supplies the entire amount of air necessary for complete combustion to the burner. In burners that use the all-primary premixing system, in which gas is forcibly taken in and mixed in advance by a centrifugal blower when gas is supplied, a small device is used to reliably mix air and fuel gas, resulting in a short flame in the burner. The present invention relates to an air intake structure of an all-primary premix burner that is both compact and compact.

(Prior Art) Burners that use gas as fuel can be broadly classified into a diffusion combustion type and a premix combustion type.

Among the diffusion combustion type devices, there is a so-called Bunsen burner, which is commonly used in home water heaters.

This Bunsen burner uses some combustion air,
For example, approximately half of the required amount of air is mixed in beforehand when supplying fuel gas to the burner, but this is insufficient for combustion, so the remaining combustion air is used as secondary air. This is a method in which fuel gas is supplied near the flame opening, and the turbulent flow created by the vortices at that time causes it to diffuse and mix with a sufficient amount of air to completely burn the fuel gas.

In addition, the premix combustion method, for example,
There is a gas instantaneous water heater proposed in Publication No. 60-146250.

When supplying fuel gas to the burner, this gas instantaneous water heater has a blower outlet located near the gas supply nozzle of the gas supply pipe, which forcibly sends in combustion air to meet the needs of combustion. This is an all-primary premixing system in which all the air is taken in during gas supply and sent to the flame port through a narrow mixer.

(Problems to be solved by the invention) <Problems with conventional technology> However, in the case of the diffusion combustion method, about half of the primary air is sucked in in advance and mixed in the ventilate section, and then the secondary air is mixed. Since it is supplied near the flame opening, the ventilate area must be sufficiently wide, and the mixture of secondary air is dominated by natural diffusion, which inevitably results in a long flame during combustion. Therefore, there is a problem in that it is not possible to achieve a short flame, etc., and it is not possible to achieve miniaturization and high-load combustion at the same time.

In addition, in the case of a premix combustion method, especially in the case of the type of gas instantaneous water heater mentioned above, the distance between the gas supply nozzle and the flame opening is short, and the mixing of combustion air and fuel gas in the mixer is not very easy. Since a complete mixing state cannot be obtained without this process, there is a problem in flame stability and uniformity.

On the other hand, even if the mixer part is made larger to ensure sufficient mixing, in reality, sufficient mixing will not be achieved unless a stirring device or the like is built-in, and the problem is that the mixer becomes relatively large. The dot was hot.

<Technical Issues> Therefore, in view of the above-mentioned problems, this invention was developed to enable sufficient mixing of combustion air and fuel gas in a burner of the all-primary premixing method using a small-sized burner. Ensure complete mixing,
As a result, it was devised to provide a burner with a shorter flame and a smaller overall size at a lower cost.

[Structure of the device] (Means for solving the problem) This device uses a centrifugal blower to forcibly take in and mix all the air necessary for complete combustion in advance when supplying fuel gas. In the air intake section of the all-primary premix burner for combustion, a fuel gas supply nozzle is disposed close to the suction port of the impeller of the centrifugal blower, and the driving force of the centrifugal blower causes the impeller of the centrifugal blower to A gas mixing device having a gas mixing blade that rotates concentrically between the suction port and the fuel gas supply nozzle and rotates and stirs in a direction substantially perpendicular to the suction direction is provided on the burner side with respect to the supply nozzle. This solves the above-mentioned problems.

(Function) When supplying fuel gas, this air intake is used in the air intake part of the primary premix burner, which uses a centrifugal blower to forcibly take in all the air necessary for complete combustion in advance, mix it, and burn it. When injecting fuel gas into the inlet from the nozzle, the gas mixing device is operated by the driving force of the centrifugal blower.

In this case, when using a centrifugal blower alone, the air and fuel gas are not mixed well and often flow as a laminar flow, but at the time of suction, the gas mixing blade rotates in a direction approximately perpendicular to the suction direction. Since the combustion air is stirred, the combustion air and the fuel gas are completely stirred and mixed when the fuel gas is supplied.

(Embodiments) Hereinafter, embodiments of this invention will be described with reference to the drawings.

That is, the reference numeral 1 shown in the figure is an all-primary premix burner, which is disposed in front of the centrifugal blower 2 and the air outlet 7 of the centrifugal blower 2, and is formed so as to uniformly send the mixed gas to the entire burner face plate 4 described later. It consists of a dispersion plate 3, a flame face plate 4 disposed in front of the dispersion plate 3, and a casing 8 surrounding these.

The centrifugal blower 2 has a motor 9 arranged approximately in the center.
This fan has an impeller 10 that rotates around the impeller 10 by the driving force of the motor 9, and a suction port 11 arranged on the side of the rotation of the impeller 10.

The dispersion plate 3 is formed by stacking one or more perforated plates with small holes as appropriate, and the flame face plate 4 has a thickness of about 2 mm to 5 mm and has a large number of small holes. It is formed from a perforated plate, and the open end of the small hole serves as the flame port 12.

The impeller 10 has blades 1 attached to a blade support 14 fixed to the drive rotation shaft 13 of the motor 9.
5 is attached and rotated. or,
A suction port 11 is opened approximately at the center of the rotating side surface of the impeller 10, through which fuel gas and combustion air can be taken in.

On the other hand, a gas supply nozzle 6 for injecting fuel gas from the gas supply pipe 5 into the suction port 11 is disposed at a position close to the outside facing the suction port 11. The fuel gas is sucked into the centrifugal blower 2 together with air and sent to the flame face plate 4.

Then, inside the suction port 11, actually the suction port 11
A gas mixing blade 16 serving as a gas mixing device is disposed at a position facing the gas supply nozzle 6 between the gas supply nozzle 6 and the gas supply nozzle 6 so as to rotate and stir the gas in a direction substantially perpendicular to the suction direction to the suction port 11. The gas mixing blade 16 is fixed to the drive rotation shaft 13 of the motor 9 and is formed to rotate concentrically with the impeller 10.

The shape of the gas mixing vane 16 is a cross star shape in the illustration, but it is designed so that the fuel gas and combustion air to be sucked in are stirred and mixed in a direction substantially perpendicular to the suction direction. The gas supply nozzle 6 may be in any shape as long as it operates, and the position of the gas supply nozzle 6 may be at the center of the gas mixing vane 16 or may be offset therefrom. In short, the fuel gas and the combustion air may be stirred and mixed at the position of the suction port 11.

In addition, as another embodiment, as shown in FIG.
The gas mixing blade 16 is attached to the blade support 14 and formed to rotate, and in this case, the centrifugal blower 2 is used so that the blade support 14 takes in the fuel gas from the gas supply nozzle 6. As is clear from a comparison of FIGS. 2 and 3, a centrifugal blower 2 with an impeller 10 having a slightly different structure from that used in the above-described embodiment of FIG. 2 is used.

All primary premix burner 1 formed in this way
is used for domestic water heater B. That is,
A heat exchanger 19 consisting of a water pipe 17 and heat exchange fins 18 is used by disposing a flame outlet face plate 4 to face the heat exchanger 19.

Then, since the fuel gas and the combustion air are stirred and mixed by the gas mixing blade 16 at the suction port 11, they are sufficiently mixed at the stage of suction by the centrifugal blower 2, so that during combustion at the flame port 12, In addition, unstable combustion due to insufficient mixing of combustion air is eliminated, and uniform combustion and short flame length are achieved. As a result, the distance between the heat exchanger 19 and the burner face plate 4 can be extremely reduced, and since the fuel gas is mixed with a sufficient amount of air necessary for combustion in advance, the burner 19 Even if the interval between the burners is very narrow, there will be no adverse effect on combustion, high-load combustion can be performed in a small space, and the all-primary premix burner 1 can be downsized.

[Effects of the invention] This invention configured as described above is a fully primary system in which, when supplying fuel gas, all the air necessary for complete combustion is forcibly taken in in advance by the centrifugal blower 2, mixed, and then combusted. In the air intake section of the premix burner 1, a fuel gas supply nozzle 6 is arranged close to the suction port 11 of the impeller 10 of the centrifugal blower 2, and the centrifugal blower 2 is driven by the driving force of the centrifugal blower 2. The supply nozzle 6 is a gas mixing device having a gas mixing blade 16 that rotates concentrically between the suction port 11 of the impeller 10 and the fuel gas supply nozzle 6 and rotates and stirs the gas in a direction substantially perpendicular to the suction direction. However, because the centrifugal blower 2 is installed on the burner 1 side, the sucked air and fuel gas often do not mix very well and flow as a laminar flow, but at the time of suction, there is a Since the gas mixing blades 16 rotate and stir in substantially orthogonal directions, the combustion air and the fuel gas are completely stirred and mixed when the fuel gas is supplied.

Therefore, the fuel gas and combustion air can be sufficiently stirred and mixed by the gas mixing device at the stage of air intake in the centrifugal blower 2, so even if the distance between the centrifugal blower 2 and the burner face plate 4 is short, the mixture can be maintained. The shortage is eliminated, and since a sufficient amount of combustion air necessary for combustion can be mixed into the fuel gas at that time, the flame can be stabilized and homogenized during combustion at the flame port 12 of the flame port face plate 4. At the same time, it is possible to achieve a shorter flame. As a result, the distance between the flame ports 12 can be made extremely small, and the distance between the heat exchanger 19 and the flame port face plate 4 can be made extremely small. , and the heat exchanger 19 can be made smaller.

As described above, according to this invention, it is possible to sufficiently mix the fuel gas and the combustion air using a small device to ensure a complete mixing state, and as a result, a short flame is achieved. It has become possible to promote high-load combustion, and has practical beneficial effects such as being able to provide a smaller, larger-capacity home water heater at a lower cost than conventional home water heaters. play.

[Brief explanation of the drawing]

The drawings show an embodiment of this invention; Fig. 1 is a partially cutaway front view when it is installed in a domestic water heater, Fig. 2 is a side sectional view, and Fig. 3 is a diagram of another embodiment. FIG. B...Home water heater, 1...All primary premix burner, 2...Centrifugal blower, 3...Dispersion plate, 4...
... Burner face plate, 5 ... Gas supply pipe, 6 ... Gas supply nozzle, 7 ... Air outlet, 8 ... Casing, 9
... Motor, 10 ... Impeller, 11 ... Suction port, 12 ... Flame port, 13 ... Drive rotation shaft, 14 ...
...Blade support, 15...Blade, 16...Gas mixing impeller, 17...Water pipe, 18...Fin, 19...
Heat exchanger.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. Air intake of a full primary premix burner that uses a centrifugal blower to forcibly take in all the air necessary for complete combustion in advance and mix it before combustion when supplying fuel gas. In the inlet section, a fuel gas supply nozzle is disposed close to the suction port of the impeller of the centrifugal blower, and the driving force of the centrifugal blower causes a flow between the suction port of the impeller of the centrifugal blower and the fuel gas supply nozzle. An all-primary premix burner characterized in that a gas mixing device having a gas mixing blade that rotates concentrically and rotates and stirs in a direction substantially perpendicular to the suction direction is provided on the burner side with respect to the supply nozzle. Air intake structure. 2. A centrifugal blower is a utility model consisting of a Shirotsko fan, which has a motor placed approximately in the center, an impeller that rotates around it due to the driving force of the motor, and a suction port placed on the side of the rotation of the impeller. An air intake structure of an all-primary premix burner as claimed in claim 1. 3. The gas mixing device is an all-in-one device as set forth in claim 1 or 2 of the utility model registration claim, in which a gas mixing blade that is attached to the drive shaft of a centrifugal blower and rotates is arranged to face a fuel gas supply nozzle. Premix burner air intake structure. 4. The gas mixing device is a registered utility model in which rotating gas mixing blades are attached to a blade support that supports the blades of the impeller of a centrifugal blower to rotate them, and are arranged to face a fuel gas supply nozzle. An air intake structure for an all-primary premix burner according to claim 1 or 2.