WO1995006843A1

WO1995006843A1 - Air charging device for gas boiler using pre-mixing type gas burner

Info

Publication number: WO1995006843A1
Application number: PCT/KR1994/000033
Authority: WO
Inventors: Jin Min Choi
Original assignee: Jin Min Choi
Priority date: 1993-08-31
Filing date: 1994-04-15
Publication date: 1995-03-09
Also published as: AU6513694A; KR960009450Y1; KR950006840U

Abstract

An air charging device for a gas boiler using a pre-mixing type gas burner. Both the gas burner (4) and the gas nozzle (8) of this device are shielded from the closed room so that no room air is used for combustion of the gas but the atmospheric air is used as both the first combustion air and the secondary combustion air. The device includes an air charging case (3) receiving the gas burner (4) and the gaz nozzle (8) therein. The burner support plate (5) supporting the gas burner (4) thereon is detachably mounted on the base (2) so as to be separated along with the gas burner (4) from the air charging case (3). The air intake (6) is provided on the air charging case (3) and coupled to the air pipe (9) extending to the atmosphere, thus to supply atmospheric air into the air charging case (3). The diffuser (7) is mounted on a diffuser mount (15) of the air charging case (3) and tightly seats therein a bottom of the heat exchanger (10). The diffuser (7) has a perforated air diffusing plate (7a) section which achieves a uniform supply of secondary air from the air charging case (3) to the outside of the perforated upper section of the combustion cylinder (4a) and partially shields the air charging case (3) from the combustion chamber (11).

Description

AIR CHARGING DEVICE FOR GAS BOILER USING PRE-MIXING TYPE GAS BURNER

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates in general to an air charging device for a gas boiler and, more particularly, to a structural improvement of an air charging device for a gas boiler using a pre-mixing type gas burner.

Description of the Prior Art

Conventionally, small-sized gas burners for use in gas boilers are classified into two types, that is, Bunsen burners and pre-mixing type burners. A Bunsen burner ejects the gas under pressure through a gas nozzle so as to mix the gas with outside air and to burn the mixed gas as shown in Fig. 1. A pre-mixing type burner mixes the gas with the outside air prior to introduction of the mixed gas into a combustion cylinder 4'a through a Venturi tube 4'b as shown in Fig. 2. The mixed gas in the combustion cylinder 4'a of this pre-mixing type burner 4' is ejected from flame holes a' of the cylinder 4'a while being burnt. In a gas boiler including the pre-mixing type burner, an air cylinder 3' receives therein only the combustion cylinder 4'a and supplies the secondary air, used in combustion of mixed gas ejected from the combustion cylinder 4'a, from the outside, as shown in Fig. 3. In this regard, it is impossible to supply the first combustion air, which air is to be mixed with the gas ejected from a gas nozzle 8' directing to the gas intake of the Venturi tube 4'b, from the outside.

Hence, the pre-mixing type burner 4' should consume the room air, for example, air inside the kitchen where the boiler is installed and somewhat closed. Such a consumption of the room air causes shortage of oxygen of the first combustion air introduced into the combustion cylinder 'a through the Venturi tube 4'b of the burner 4' and, as a result, causes incomplete combustion of the gas. In addition, when there is generated flashback in the combustion chamber 11' of the combustion cylinder 4', the exhaust gas may be backed through the Venturi tube 4'b, thus to cause a danger of gas poisoning.

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide an air charging device for a gas boiler using a pre-mixing type gas burner in which the aforementioned problems can be overcome and a connection part of the Venturi tube and the gas nozzle at which the gas is first mixed with the air is shielded from the closed room so that the room air is prevented from introduction into the combustion cylinder and the first combustion air as well as the secondary combustion air is supplied from the atmosphere, which air charging device improves the combustion efficiency, prevents gas poisoning, facilitates the separation and engagement of the burner from and with the air cylinder, simplifies the inner structure of the boiler case by provision of the air intake on a side of a burner support plate and facilitates the installation of the boiler.

In order to accomplish the above object, an air charging device for a gas boiler using a pre-mixing type gas burner in accordance with an embodiment of the present invention comprises: an air charging case butted on a base and placed under a combustion chamber of a heat exchanger, the air charging case having an opening on its top surface for forming a diffuser mount, the bottom of the air charging case being formed by the base; the gas burner received in the air charging case and comprising a combustion cylinder and a Venturi tube, an upper section of the combustion cylinder being perforated on its side surface and protruding into the combustion chamber of the heat exchanger; a gas nozzle for ejecting gas toward the Venturi tube, the gas nozzle received in the air charging case and spaced apart from a gas inlet end of the Venturi tube by a predetermined distance; a burner support plate supporting the gas burner thereon and detachably mounted on the base so as to be separated along with the gas burner from the air charging case; an air intake provided on the air charging case; an air pipe coupled to the air intake and extending to the atmosphere, thus to supply atmospheric air to the air charging case; and a diffuser mounted on the diffuser mount of the air charging case and tightly seating therein a bottom of the heat exchanger.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a schematic front view of a conventional

Bunsen burner;

Fig. 2 is a schematic front view of a conventional pre-mixing type burner having a Venturi tube; Fig. 3 is an air cylinder for the pre-mixing type burner for use in a gas boiler;

Fig. 4 is an exploded perspective view of an air charging device in accordance with a primary embodiment of the present invention; Fig. 5 is a sectional view of the air charging device of Fig. 4 after assembled;

Fig. 6 is an exploded perspective view of an air charging device in accordance with a second embodiment of the present invention; Fig. 7 is a sectional view of the air charging device of Fig. 6 after assembled;

Fig. 8 is a perspective view of an air charging device in accordance with a third embodiment of the present invention;

Fig. 9 is a sectional view of the air charging device of Fig. 8; and

Figs. 10 and 11 are perspective views of air charging devices in accordance with further embodiments of the present invention, respectively.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Figs. 4 and 5 are an exploded perspective view and a sectional view of an air charging device for a gas boiler using a pre-mixing type gas burner in accordance with a primary embodiment of the present invention, respectively. The air charging device is encased by a boiler case 1 and supported by a base 2. The device includes an air charging case 3 of which the bottom edge is butted to the base 2. Hence, the base 2 constitutes the bottom of the air charging case 3. The case 3 receives therein the pre-mixing type gas burner 4. An air diffuser 7 is seated and mounted on a diffuser mount 3a formed on the upper section of the air charging case 3. In the air charging device, a burner support plate 5 is detachably mounted, using bolts 13, on the bottom surface of the base 2 and supports thereon the gas burner 4 received in the air charging case 3. With the detachable burner support plate 5, it is facilitated to engage and separate the gas burner 4 with and from the air charging case 3. An air intake 6 for supplying the combustion air to the burner 4 from the outside downwardly extends from the burner support plate 5. Coupled to this air intake 6 is an air pipe 9 arranged at the outside of the boiler and extending to the atmosphere. In order to make the inside of the air charging case 3 communicating with the atmosphere through the air intake 6 and the air pipe 9, the base 2 is provided with an opening at a position corresponding to the air intake 6 of the plate 5.

The gas burner 4 seated on and mounted on the burner support plate 5 includes a combustion cylinder 4a. This cylinder 4a is mounted on the burner support plate 5 by a reverse U-shaped support 4c and protrudes into a combustion chamber of a heat exchanger 10 at its perforated upper section. A Venturi tube 4b is horizontally coupled to the lower section of the combustion cylinder 4a in the air charging case 3. The gas inlet end of the Venturi tube 4b is spaced apart from a gas nozzle 8 by a predetermined distance as shown in Figs. 4 and 5. The gas nozzle 8 is fitted to the side wall of the air cylinder 3. In placing the Venturi tube 4b in the air charging case 3, the tube 4b is stably suspended above the burner support plate 5 by a support column 4d and tightened to the column 4d by a tightening band 4e. The gas inlet end of the Venturi tube 4b is precisely centered with the gas nozzle 8.

As shown in Figs. 4 and 5, the diffuser 7 seated and mounted on the air charging case 3 has a double structure for supplying secondary air and supporting a heat exchanger 10 thereon as will be described later herein. The diffuser 7 is seated on the diffuser mount 3a formed on the upper section of the air charging case 3, which case 3 receives the combustion cylinder 4a therein. When seating the diffuser 7 on the diffuser mount 3a, a perforated air diffusing plate section 7a having a plurality of air diffusing holes "b" is deep depressed into the air charging case 3. With the deep depressed plate section 7a of the diffuser 7, sufficient secondary air is supplied from the air charging case 3 to the outer surface of the upper section of the combustion cylinder 4a protruding into the combustion chamber in the heat exchanger 10. The upper section of the cylinder 4a protruding into the combustion chamber is provided with a plurality of flame holes "a" formed on its side surface. On the other hand, the outer edge of the diffuser 7 upwardly extends and tightly seats therein the bottom of the heat exchanger 10 of a boiler body. Alternatively, the air diffusing section 7a of the diffuser 7 can not be depressed but flattened as shown in Figs. 6 and 7. In this case, the outer edge of the diffuser 7 upwardly extends and tightly seats therein the bottom of the heat exchanger 10.

In the primary and second embodiments shown in Figs. 4 and 6, the air charging case 3 comprises a cylinder section and a rectangular section which are cast as a single body as shown in Figs. 4 and 6. The cylinder section of the air charging case 3 supports both the diffuser 7 and the heat exchanger 10 and receives therein the lower section of the combustion cylinder 4a while the rectangular section of the air charging case 3 receives therein the Venturi tube 4b. However, the air charging case 3 may have a rectangular outer appearance which nearly covers the base 2 as shown in Fig. 8.

The air intake 6 for introducing the outside air into the air charging case 3 is preferably provided on the burner support plate 5 detachably mounted on the bottom surface of the base 2 as shown in Figs. 5 and 7. In this case, the air pipe 9 coupled to the air intake 6 is arranged at the outside of the boiler case and extends to the atmosphere. However, it should be understood that the air intake 6 may be provided on the top surface of the air charging case 3 as shown in Figs. 8 to 11. In this case, the air pipe 9 coupled to the air intake 6 is arranged in the boiler case and extends to the atmosphere.

In the drawings, the reference numerals 14 denotes a governor, 15 denotes a mount for mounting the heat exchanger 10 on the air charging case 3 and 16 denotes an exhaust port. As described above, all the elements of the pre- mixing type burner 4 as well as the gas nozzle 8 are received in the air charging case 3 such that they are shielded from the outside of the case 3. Therefore, the fresh air which has been introduced from the atmosphere to the air charging case 3 through the air pipe 9 is used as both the first combustion air, which air is to be mixed with the gas ejected from the gas nozzle 8 to the Venturi tube 4b, and the secondary combustion air for use in combustion of the mixed gas ejected from the flame holes "a" of the protruding upper section of the combustion cylinder 4a. In this regard, supply of sufficient oxygen for the mixed gas out of the combustion cylinder 4a is achieved, thus to improve the combustion efficiency of the burner 4. It will be thus noted that the air charging device of this invention uses no room air, which room air is, for example, air inside the kitchen where the boiler is installed and somewhat closed. With the fact that the device uses no room air, there is no danger of loss of lives caused by shortage of oxygen and gas poisoning.

When the gas is ejected from the gas nozzle 8 during operation of the boiler, the fresh air in the air charging case 3, which case 3 communicates with the atmosphere through the air pipe 9, is introduced into the Venturi tube 4b along with the gas so as to be mixed with the gas. Thus, the introduction of the first combustion air of the outside air into the Venturi tube 4b is achieved. The mixed gas resulting from mixing of the gas with the first combustion air is introduced into the combustion cylinder 4a and, thereafter, ejected from the flame holes "a" of the cylinder 4a and ignited to be burnt. At this time, sufficient secondary air is supplied ^→z.o the outer surface of the combustion cylinder throu . the air diffusing holes "b" of the diffuser 7 ated on the difruser mount 3a of the air charging case

, thus t achieve supply of sufficient amount of oxygen to the mixed gas ejected from the flame holes "a" of the combustion cylinder 4a and to achieve complete combustion of the mixed gas. In addition, the gas burner 4 received in the air charging case 3 is fixedly mounted on the burner support plate 5, which plate 5 is screwed to the base 2 using bolts 13. With such a mounting structure of the gas burner 4, the burner 4 can be easily separated from the air charging case 3 by simple loosening of the bolts 13 and separation of the burner support plate 5 from the base 2.

With the diffuser 7 for supply of the secondary air to the outer surface of the protruding upper section of the combustion cylinder 4a, the assembling ability of the heat exchanger 10 as well as the combustion efficiency of the burner 4 is remarkably improved. That is, the outer edge of the diffuser 7 upwardly extends and tightly seats therein the bottom of the heat exchanger 10 so that it is facilitated to assemble the heat exchanger 10. In addition, since the perforated diffusing section 7a having the plurality of air diffusing holes "b" is deep depressed, sufficient secondary air is supplied from the air charging case 3 to the outer surface of the perforated upper section of the combustion cylinder 4a through the air diffusing holes "b", thus to remarkably improve the combustion efficiency of the burner 4. A collateral advantage of mounting of the diffuser 7 on the diffuser mount 3a of the air charging case 3 is to partially shield the combustion chamber 11 of the heat exchanger 10 from the air charging case 3.

As described above, the gas burner of the air charging device for a gas boiler of the present invention can be easily separated from the air charging case, thus to provide a good convenience in exchange of the burner, in repair of troubled elements of the burner and in cleaning of the burner. The fresh outside air is used as the combustion air, that is, the first combustion air and the secondary combustion air which are to be supplied to the pre-mixing type burner, so that the combustion efficiency of the burner is improved. Since both the gas burner and the gas nor .e are received in the air charging case such that they are completely shielded from the outside of the boiler case, the atmospheric air is used in combustion of the gas. A collateral advantage of receiving both the gas burner and the gas nozzle in the air charging case is to prevent a danger of gas poisoning since the exhaust gas can be directly exhausted to the atmosphere through the air pipe 9 even when there is generated a flashback in the combustion cylinder. The outer edge of the diffuser upwardly extends and tightly seats therein the heat exchanger and the perforated diffusing section of the diffuser is preferably deep depressed into the air charging case when it is mounted on the air charging case. The diffuser thus improves the assembling ability of the heat exchanger and, furthermore, supplies sufficient secondary air to the outer surface of the perforated upper section of the combustion cylinder protruding into the combustion chamber, thus to achieve a desired combustion efficiency of the burner and improve the reliability of the boiler.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

WHAT IS CLAIMED IS:

1. An air charging device for a gas boiler using a pre-mixing type gas burner comprising: an air charging case butted on a base and placed under a combustion chamber of a heat exchanger, said air charging case having an opening on its top surface for forming a diffuser mount, the bottom of said air charging case being formed by said base; said gas burner received in said air charging case and comprising a combustion cylinder and a Venturi tube, an upper section of said combustion cylinder being perforated on its side surface and protruding into said combustion chamber of the heat exchanger; a gas nozzle for ejecting gas toward said Venturi tube, said gas nozzle received in said air charging case and spaced apart from a gas inlet end of said Venturi tube by a predetermined distance; a burner support plate supporting said gas burner thereon and detachably mounted on said base so as to be separated along with said gas burner from said air charging case; an air intake provided on said air charging case; an air pipe coupled to said air intake and extending to the atmosphere, thus to supply atmospheric air to said air charging case; and a diffuser mounted on said diffuser mount of the air charging case and having the bottom of said heat exchanger tightly seated therein.

2. The air charging device according to claim 1, wherein said air intake is provided on a side section of said top surface of the air charging case and said air pipe is arranged in a boiler case to extend to the atmosphere.

3. The air charging device according to claim 1, wherein said air intake is provided on a side section of said base constituting the bottom of said air charging case and said air pipe is arranged at the outside of a boiler case to extend to the atmosphere.

4. The air charging device according to claim 1, wherein said diffuser has a perforated air diffusing plate section provided with a plurality of air diffusing holes, said air diffusing plate section achieving a uniform supply of secondary air from the air charging case to the outside of the perforated upper section of said combustion cylinder and partially shielding said air charging case from said combustion chamber of the heat exchanger.

5. The air charging device according to claim 1, wherein said air charging case comprises; a cylinder section for supporting thereon said heat exchanger and receiving therein said combustion cylinder; and a rectangular section for receiving therein said Venturi tube.

6. The air charging device according to claim 1, wherein said air charging case comprises a rectangular case covering almost said base.

7. The air charging device according to claim 1, wherein the outer edge of said diffuser upwardly extends and seats therein said bottom of the heat exchanger.

8. The air charging device according to claim 4, wherein said perforated air diffusing plate section is deep depressed into said air charging case, thus to supply sufficient secondary air to the outside of said perforated upper section of the combustion cylinder.

9. The air charging device according to claim 1, wherein said combustion cylinder of the gas burner is mounted on said burner support plate by a reverse U- shaped support and said Venturi tube is supported on said burner support plate by both a support column and a tightening band such that its gas inlet end is precisely centered with said gas nozzle.