US20110053105A1

US20110053105A1 - Bunsen burner using lean-rich combustion type

Info

Publication number: US20110053105A1
Application number: US12/812,755
Authority: US
Inventors: Ho-keun Kim
Original assignee: Kyungdong Navien Co Ltd
Current assignee: Kyungdong Navien Co Ltd
Priority date: 2008-01-16
Filing date: 2008-11-24
Publication date: 2011-03-03
Also published as: KR100883796B1; WO2009091115A3; EP2232140A2; CN101910725B; WO2009091115A2; CN101910725A

Abstract

A Bunsen burner which reduces pollutant materials generated during combustion by adopting a lean combustion, enhancing combustion stability. The Bunsen burner includes burner bodies, each including: a venturi plate having a venturi hole through which a gas mixture is introduced, wherein air supplied from a fan is mixed with fuel jetted from a nozzle unit, a guide plate for guiding the gas mixture upward, an inclined portion having first flame holes for jetting the gas mixture at an oblique angle with respect to the vertical direction, a side portion that extends downward from a lower side of the inclined portion and includes through-holes through which some of the gas mixture passes, and a connection plate having opposed ends connected to the side portions of the burner bodies, respectively, and having second flame holes in which the gas mixture passing through the through-holes and secondary air, introduced by the fan and supplied along outer surfaces of the burner bodies, are mixed so that lean combustion occurs.

Description

TECHNICAL FIELD

The present invention relates to a Bunsen burner using a lean-rich combustion type, and more specifically, to a Bunsen burner which can reduce pollutant materials generated during combustion by adopting a lean-rich combustion type, thereby enhancing combustion stability.

BACKGROUND ART

In general, combustion types for gas fuel are divided into a premixed combustion type, a diffusion combustion type, and a partial premixed combustion type. In the premixed combustion type, gas fuel and combustion air are premixed and are then supplied to a combustion chamber. In the diffusion combustion type, fuel and air are separately supplied. In the partial premixed combustion type, the premixed combustion type and the diffusion combustion type are mixed.
The partial premixed combustion is performed by a Bunsen burner. The Bunsen burner premixes fuel and some of the air required for combustion as primary air, and then supplies the gas mixture. Apart from the primary air, the Bunsen burner supplies secondary air to portions where flames are formed, thereby inducing perfect combustion.
The diffusion combustion has excellent flame stability, but generates a large quantity of pollutant materials such as CO, NOx, and so on. In the case of the premixed combustion type, a small quantity of pollutant materials such as CO, NOx, and so on is generated. However, when the combustion is performed in a low-load region, back fire may occur. Further, when a load is increased, the airflow velocity of the gas mixture increases, forming unstable flames.
The Bunsen burner, which has adopted advantages of the diffusion combustion and the premixed combustion, can not only reduce the generation of pollutant materials, but can also enhance flame stability.
Meanwhile, a lean-rich burner is known as a burner obtained by modifying the structure of the Bunsen burner.
In the lean-rich burner, rich combustion and lean combustion simultaneously occur. In the rich combustion, a gas mixture in which an amount of fuel is larger than an amount of required air is burned. In the lean combustion, a gas mixture in which an amount of fuel is smaller than an amount of required air is burned.
That is, the lean-rich burner adopts a structure that supplies secondary air separately from a gas mixture in which primary air and rich fuel are mixed, and simultaneously, mixes lean fuel with the secondary air so as to burn the gas mixture.
Such a lean-rich burner has advantages in that a small quantity of pollutant materials is generated, the flame stability is excellent, and the length of flames decreases. Therefore, the lean-rich burner has been adapted to and used in gas boilers.

DISCLOSURE

Technical Problem

The present invention is directed to a Bunsen burner which can reduce pollutant materials generated during combustion by adopting a lean-rich combustion type, thereby enhancing combustion stability.

Technical Solution

According to an aspect of the present invention, a Bunsen burner using a lean-rich combustion type includes a plurality of burner bodies including: a venturi plate having a venturi hole formed therein such that a gas mixture in which a portion of air supplied from a fan as primary air is mixed with fuel jetted from a nozzle unit is introduced; a guide plate for guiding the introduced gas mixture upward; an inclined portion having a plurality of first flame holes for jetting the gas mixture at a predetermined angle with respect to the vertical direction; and a side portion that extends downward from a lower side of the inclined portion and has a plurality of through-holes formed therein such that some of the gas mixture passes; and a connection plate having both ends connected to the side portions of the burner bodies, respectively, and having a plurality of second flame holes in which the gas mixture passing through the through-holes and secondary air introduced by the fan and supplied along outer surfaces of the burner bodies are mixed so that lean combustion occurs.
The connection plate may be coupled to the uppermost end of the side portion of the burner body.
Each of the burner bodies may include a burner upper plate including a first horizontal portion which is provided at the upper end of the burner upper plate and is formed of a plane having a predetermined width, a first inclined portion which extends from the first horizontal portion so as to be inclined downward and has the first flame holes formed therein, and a first side portion which extends from the first inclined portion and has the through-holes formed therein; and a burner lower plate installed symmetrically with the burner upper plate in the vertical direction.

Advantageous Effects

In a Bunsen burner according to the present invention, flame holes are formed in an inclined manner such that a flame stabilizing function is enhanced, the entire width of the burner body can be reduced, and secondary air can be easily supplied. Therefore, combustion performance is enhanced. Further, as the lean-rich combustion type is applied to the Bunsen burner, generation of pollutant materials is reduced, and flame stability is enhanced.

DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional side view of a burner according to the present invention.

FIG. 2 is an assembled perspective view of burner bodies and connection plates according to the present invention.

FIG. 3 is an exploded perspective view of the burner bodies and the connection plates shown in FIG. 2.

FIG. 4 is a schematic view showing an operation state of the burner according to the present invention.

FIG. 5 is a schematic view showing a state in which a gas mixture is supplied through a nozzle unit and a venturi hole according to the present invention.

FIG. 6 is a schematic view showing a state in which rich combustion and lean combustion occur in the burner according to the present invention.

MODE FOR INVENTION

Hereinafter, example embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a cross-sectional side view of a burner according to the present invention. FIG. 2 is an assembled perspective view of burner bodies and connection plates according to the present invention. FIG. 3 is an exploded perspective view of the burner bodies and the connection plates shown in FIG. 2.
Referring to FIG. 1, the burner includes a casing unit 10 having an installation region formed therein, in which components of the burner are to be installed, a fan 20 which is connected and installed under the casing unit 10 so as to provide external air into the casing unit 10, a nozzle unit 30 which is connected and installed in one side of the casing unit 10 and has a leading end portion positioned inside the casing unit 10 so as to jet gas, and a burner body 100 which is installed inside the casing unit 10 so as to form flames.
A heat exchanger 1 is installed above the burner body 100.
The burner body 100 is positioned in the upper portion of the casing unit 10 and includes a burner upper plate 110 and a burner lower plate 120 which are coupled so as to face each other in a vertical direction, thereby forming an octagonal shape.
The burner upper plate 110 includes a first horizontal portion 114 which is provided at the upper end of the burner upper plate 110 and is formed of a plane having a predetermined width, a first inclined portion 116 which is formed at either end of the first horizontal portion 114 so as to be inclined downward and has a plurality of first flame holes 112 spaced a predetermined distance from each other along the longitudinal direction of the burner upper plate 110, and a first side portion 118 which is formed to extend from the lower end of the first inclined portion 116 in the vertical direction and has a plurality of through-holes 113 spaced a predetermined distance from each other along the longitudinal direction of the burner upper plate 110.
As the first flame holes 112 formed in the first inclined portion 116 jet a gas mixture at a predetermined angle with respect to the vertical direction, it is possible to minimize lifting of flames (that is, to stabilize flames). In this case, the first inclined portion 116 may be inclined at various angles.
By minimizing the width of the first horizontal portion 114 of the burner upper plate 110, it is possible to prevent deterioration caused by flames formed from the first flame holes 112.
The burner lower plate 120 is installed so as to be connected to the lower side of the burner upper plate 110 and includes a second horizontal portion 124 which is provided at the lower end of the burner lower plate 120 and is formed of a plane having a predetermined width, a second inclined portion 126 which is formed at either end of the second horizontal portion 124 so as to be inclined upward, and a second side portion 128 which extends upward from the upper end of the second inclined portion 126.
The burner lower plate 120 has a venturi plate 200 installed in one side thereof. The venturi plate 200 is installed on one opened side surface of the burner body 100, the opened side surface being positioned in front of the nozzle unit 30. The venturi plate 200 has a venturi hole 210 formed therein such that a gas mixture in which gas jetted from the nozzle unit 30 and primary air supplied from the fan 20 are mixed can be introduced into the burner body 100 through the venturi hole 210.
The burner lower plate 120 has an end plate 300 installed in the other side thereof such that the end plate 300 faces the venturi plate 200.
The burner body 100 has a guide plate 400 which is horizontally installed inside the burner body 110. The gas mixture introduced through the nozzle unit 30 and the venturi hole 210 is guided by the guide plate 400 so as to be supplied to an upper portion of the burner body 100.
The guide plate 400 is installed in such a manner that one end thereof is closely attached to the venturi plate 200 and the other end thereof is separated from the end plate 300. Therefore, the gas mixture introduced through the venturi hole 210 is guided toward the end plate 300 by the guide plate 400 and is then supplied to the inside of the burner upper plate 110.
The burner upper and lower plates 110 and 120 are formed of metal. For example, the burner upper plate 110 may be formed of stainless steel, and the burner lower plate 120 may be formed of steel.
In this example embodiment, at least one burner body 100 is installed inside the casing unit 10. Preferably, three burner bodies 100 are installed in parallel so as to be spaced a predetermined distance from each other.
A connection plate 600 is installed in either side of each of the burner bodies 100. The connection plate 600 has a plurality of second flame holes 610 formed along the longitudinal direction thereof, the second flames holes 610 being spaced a predetermined distance from each other. The long side of the connection plate 600 formed in a rectangular shape is coupled to the first side portion 118 of the burner body 100.
In this case, the connection plate 600 may be coupled to the uppermost end of the first side portion 188 of the burner body 100 such that the air can be smoothly supplied to flames formed in the first flame holes 112.
The burner body 100 has a secondary-air diffusion plate 500 installed on the lower surface thereof. One end of the secondary-air diffusion plate 500 is connected to the casing unit 10 and the burner body 100 so as to extend horizontally toward the nozzle unit 30, and the other end thereof has a bent portion 510 which is bent upward.
The secondary-air diffusion plate 500 has secondary-air jetting holes 520 formed therein, and the bent portion 510 has a fixing hole 512 to which the venturi hole 210 of the venturi plate 200 is fixed.
Operation of the Bunsen burner constructed in such a manner will be described with reference to FIGS. 4 to 6.
FIG. 4 is a schematic view showing an operation state of the burner according to the present invention. FIG. 5 is a schematic view showing a state in which a gas mixture is supplied through the nozzle unit and the venturi hole according to the present invention. FIG. 6 is a schematic view showing a state in which rich combustion and lean combustion occur in the burner according to the present invention.
Fuel supplied through a fuel supply unit (not shown) is jetted from the nozzle unit 30 into the venturi hole 210 at high velocity.
Meanwhile, the air supplied from the lower side of the casing unit 10 through the fan 20 is divided into the primary air introduced into the venturi hole 210 and the secondary air jetted from the lower side to the upper side through the secondary-air jetting hole 520.
The fuel jetted from a nozzle end of the nozzle unit 30 is mixed with the primary air around the nozzle unit 30 when passing through the venturi hole 210 of the venturi plate 200, and is then supplied as a gas mixture into the burner body 100 so as to flow in an arrow direction.
The primary air and the fuel jetted from the nozzle unit 30 are sufficiently mixed by the guide plate 400 while the primary air moves from a position A to a position B, and the guide plate 400 stably guides the primary air mixed with the fuel to the inside of the burner upper plate 110.
The secondary air jetted upward through the secondary-air jetting holes 520 is supplied along the outer surfaces of the burner bodies 100. That is, the secondary air is guided upward along a space between the side portions 118 and 128 of two burner bodies 100 adjacent to each other.
The gas mixture supplied into the burner upper plate 110 via the guide plate 400 is ignited at the first flame holes 112 formed in the first inclined portion 116 so as to form flames. In this case, the gas mixture which has been mixed with the primary air so as to be supplied into the burner upper plate 110 is in a rich state, in which the amount of the fuel is larger than an amount of required air. Therefore, the rich combustion occurs in the first flame holes 112.
Further, some of the gas mixture supplied into the burner upper plate 110 is jetted through the through-holes 113 formed in the first side portion 118 so as to be supplied to a space between the first side portions 118 of two burner bodies 110.
The gas mixture jetted through the through-holes 113 is mixed with the secondary air jetted upward through the secondary-air jetting holes 520, and is then jetted through the second flame holes 610 formed in the connection plate 600 so as to form flames.
In this case, the gas mixture mixed with the secondary air is in a lean state, in which the amount of the fuel is smaller than an amount of required air. Therefore, the lean combustion occurs in the second flame holes 610.
Since the first flame holes 112 are formed in the inclined surface, they reduce the airflow velocity of the gas mixture jetted through the first flame holes 112, thereby preventing lifting of the flames. Therefore, the combustion state can be maintained stably.
Further, since the rich combustion occurs in the first flame holes 112 and the lean combustion occurs in the second flame holes 610, the burner according to the present invention has the same advantage as that of the conventional lean-rich burner in that a small quantity of pollutant materials is generated and flame stability is excellent.
The flames formed in the second flame holes 610 have an effect upon the flames formed in the first flame holes 112, thereby further reducing the generation of CO.
That is, an amount of CO increases in the rich combustion state. When the through-holes 113 are not formed in the first side portion 118 and the connection plate 600 is not provided, the burner according to the present invention has the same structure as the conventional Bunsen burner. In this case, the secondary air is not sufficiently supplied to the flames generated at the first flame holes 112, so that a large amount of CO is generated.
Therefore, as the through-holes 113 are formed in the first side portion 118 and the connection plate 600 is provided, that is, a structure in which the lean-rich burner is coupled to the Bunsen burner is adopted, the diffusion of air increases due to the flames formed in the second flame holes 610. Accordingly, the air is rapidly supplied toward the flames formed in the first flame holes 112, thereby reducing the generation of CO.
Further, as the connection plate 600 is positioned at the uppermost end of the first side portion 118 of the burner body 100 such that the first flame holes 112 are disposed closely to the second flame holes 610, a larger amount of air can be supplied to the flames formed at the first flame holes 112. Therefore, an effect of reducing the generation of CO increases.
While few exemplary embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes may be made to these embodiments without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.

INDUSTRIAL APPLICABILITY

Since the Bunsen burner using a lean-rich combustion type according to the present invention adopts a structure in which a lean-rich burner is coupled to a Bunsen burner, a small quantity of pollutant materials is generated, and flame stability is enhanced. Therefore, the Bunsen burner has industrial applicability.

Claims

1. A Bunsen burner comprising:

a plurality of burner bodies, each burner body including:

a venturi plate having a venturi hole located in the venturi plate and through which a gas mixture is introduced, wherein air, supplied from a fan, as primary air, is mixed with fuel jetted from a nozzle unit into the burner body,

a guide plate for guiding the gas mixture upward,

an inclined portion having a plurality of first flame holes for jetting the gas mixture at a predetermined angle oblique to the vertical direction, and

a side portion that extends downward from a lower side of the inclined portion and includes a plurality of through-holes and through which some of the gas mixture passes; and

a connection plate having opposed ends connected to respective side portions of each of the burner bodies, and having a plurality of second flame holes, wherein the gas mixture passing through the through-holes and secondary air, introduced by the fan and supplied along outer surfaces of the burner bodies, are mixed so that lean combustion occurs.

2. The Bunsen burner according to claim 1, wherein the connection plate is coupled to an uppermost end of the side portions of the burner bodies.

3. The Bunsen burner according to claim 1, wherein each of the burner bodies includes:

a burner upper plate including

a first horizontal portion which is located at an upper end of the burner upper plate, is planar, and has a predetermined width,

a first inclined portion which extends from the first horizontal portion and inclines downward and includes the first flame holes, and

a first side portion which extends from the first inclined portion and includes the through-holes; and

a burner lower plate located symmetrically with respect to the burner upper plate, in the vertical direction.