WO2006019279A1

WO2006019279A1 - Gas burner

Info

Publication number: WO2006019279A1
Application number: PCT/KR2005/002733
Authority: WO
Inventors: Hee Suck Sun; Hyun Jin Lee; Sung Geun Kim
Original assignee: Kyung Dong Boiler Co Ltd
Current assignee: Kyung Dong Boiler Co Ltd
Priority date: 2004-08-19
Filing date: 2005-08-19
Publication date: 2006-02-23
Anticipated expiration: 2007-02-19

Abstract

A gas burner is provided, which includes a burner assembly, a burner portion having fire hole units, and a manifold. The fire hole units are formed in the form of a module in which fire hole plates formed of a plate shape where a number of fire holes are formed are connected in parallel with each other. When the fire hole units are mounted in the burner portion, the total fire hole units are separated into a number of pieces. Several fire hole units each having an identical burner output range are disposed in parallel with each other, to thereby perform a combustion operation by changing the number of fire hole units according to the amount of heat. The fire hole units are formed of fire hole plates and thus are simple in their structures and the fire hole units are separated into several pieces, to accordingly prevent deformation due to a thermal stress. Also, the size and quantity of fire holes can be easily changed, to thus easily alter a burner heat capacity. Also, partitions are used in order to constitute fire hole units of a burner module having an identical burner output range, and thus the position alteration of the partitions is easily performed to accordingly make it easy to change the total output of the burner and to adjust the combustion surface area.

Description

GAS BURNER

Technical Field

[1] The present invention relates to a gas combustion burner, that is, a gas burner, and more particularly, to a gas burner where fire hole units are formed of fire hole plates only of a plate shape and thus the size and quantity of fire holes can be easily changed, to accordingly easily alter a burner heat capacity, and where partitions are used in order to constitute fire hole units of a burner module having an identical burner output range, and thus the position alteration of the partitions is easily performed, to ac¬ cordingly make it easy to change the total output of the burner and to adjust the combustion surface area. Background Art

[2] As is well-known, a boiler for heating water and supplying hot water for use in a general home, is divided into an oil boiler and a gas boiler, according to a fuel used. The oil boiler or the gas boiler uses a burner for burning oil or gas which is used in the boiler.

[3] That is, a general burner is equipment which obtains heat by burning fuel in safety and with good efficiency. According to the kind of fuel used, the burner is classified into a gas burner for combustion of gas, an oil burner for combustion of liquid fuel such as kerosene or diesel oil, and a powdered coal burner for combustion of coal.

[4] Also, the burner is divided into a premixed combustion burner and a diffusion combustion burner according to a method for mixing fuel and air.

[5] Here, the premixed combustion burner burns fuel and air which have been mixed in advance and the diffusion combustion burner burns mixed fuel and air in which fuel and air are separately supplied to a burner and mixed therein.

[6] At present, a Bunsen gas burner which is mostly a diffusion combustion gas burner is used as a home-use gas boiler.

[7] Here, the Bunsen gas burner is chiefly used in the gas fuel boiler for supplying air agitato and heightening the temperature of flame in order to raise an instantaneous agitato temperature.

[8] The Bunsen gas burner includes a main burner which oversupplies gas and an auxiliary burner which oversupplies air, in order to easily heighten an instantaneous temperature. Accordingly, the Bunsen gas burner can adjust the intensity and length of flame.

[9] In the Bunsen gas burner, the main burner is set so that an air surplus ratio is greater than 1.2, and the auxiliary burner is set so that an air surplus ratio is smaller than 0.8. [10] In this case, nitrogen oxide (NOx) of 40 through 60ppm is discharged, in comparison with the case that nitrogen oxide (NOX) of 120ppm or so is discharged when the Bunsen gas burner is operated for combustion at a constant air-to-fuel ratio.

[11] FlG. 1 is a perspective view showing a conventional Bunsen gas burner which is in operation.

[12] As shown in FlG. 1, the Bunsen gas burner 50 mixes gas with primary air 46 supplied by an air blower 42, and burns the mixed gas in a combustion chamber 45. When secondary air 47 is taken into the combustion chamber 45 in order to assist the combustion, diffusion combustion occurs.

[13] In the case of the diffusion combustion, oxygen gas lacks and fuel gas is surplus at the center of each flame, and fuel gas lacks and oxygen gas is surplus at the edge of flame. Here, diffusion of fuel gas and oxygen gas occurs continuously toward the middle point between the center and edge of each flame due to the difference in con¬ centration of the fuel gas and oxygen gas, to thus make a combustion operation continue.

[14] Here, part of carbon monooxide which is generated from the center of each flame and is not oxidized into carbon dioxide in the process of a diffusion combustion process is discharged out as it is.

[15] Meanwhile, as described above, a premixed gas burner is known in which fuel gas is mixed with primary air which is compulsively supplied by an air blower fan, at a predetermined ratio, to thus make a premixed gas, and the premixed gas is primarily burnt in a burner.

[16] The premixed gas burner includes a plurality of burners, in which an overall combustion operation for burning the premixed gas at the total burners and a partial combustion operation for burning the premixed gas at the partial burners are exchanged at a user's will.

[17] FlG. 2 is a cross-sectional view showing an example where a conventional premixed gas burner is used in a boiler device.

[18] The boiler device shown in FlG. 2 includes a premixed gas burner 42 located at the lower portion of a combustion chamber 41 and a heat exchanger 45 which heats water supplied via a water supply tube 43 into the hot water obtained by the gas burner 42 and supplies the hot water to a kitchen or bathroom via a hot water supply tube 44.

[19] The internal structure of a combustion chamber 46 in the premixed gas burner 42 is divided by partition walls 47, which includes a central mixing portion 48a, and two lateral mixing portions 48b located at either side of the central mixing portion 48a, in which a central combustion plate 49a is installed in the central mixing portion 48a, and two lateral mixing plates 49b are installed in the lateral mixing portions 48b as a burner portion. [20] Here, the mixing portions 48a and 48b mix fuel gas supplied from a gas tube 50 with primary air for combustion compulsively supplied by an air blower fan 51, to thus produce premixed gas. The premixed gas is supplied to the combustion plates 49a and 49b, respectively so as to be burnt.

[21] An air blow fan 51 is connected at the inhalation portion of the mixing portions 48a and 48b in the premixed gas burner 42.

[22] Also, the gas tube 50 is branched into a first gas tube 53 and a second gas tube 54 at the following stage of a main gas valve 52. The first gas tube 53 communicates with an air inhalation unit 51a in the air blow fan 51 via a first electronic valve 55 and the second gas tube 54 communicates with the inhalation portion of the mixing portion 48a via a second electronic valve 56.

[23] Thus, in the case of the premixed gas burner 42, the fuel gas supplied from the first gas tube 53 is mixed with primary air for combustion supplied from the air blower fan 51 at the mixing portions 48a and 48b, at the state where the main gas valve 52 and the first electronic valve 55 are open and the second electronic valve 56 is closed, to then become premixed gas. The premixed gas is supplied to the combustion plate 49a and 49b, respectively to then make an overall combustion operation proceed.

[24] Also, the fuel gas supplied from the second gas tube 54 is mixed with primary air for combustion supplied from the air blower fan 51 at the mixing portion 48a, at the state where the main gas valve 52 and the second electronic valve 56 are open and the first electronic valve 55 is closed, to then become premixed gas. The premixed gas is supplied to the combustion plate 49a, to then make a partial combustion operation proceed only by the combustion plate 49a. Also, only air is supplied to the combustion plates 49b by the air blower fan 51 via the mixing portions 48b.

[25] In the above-described premixed gas burner 42, the combustion chamber 46 is integrally formed of the mixing portions 48a and 48b which are partitioned by partitions 47 which are made of aluminum casting.

[26] However, when a plurality of mixing portions are integrally formed as described above, a mixing portion should be installed according to the kind of the premixed gas burner, in correspondence to the number of the burner portions or differences in firing forces at the time of an overall combustion or partial combustion in the burner portions. As a result, the structure of the premixed gas burner is complicated and thus casting molds should be separately fabricated, to thereby increase production cost.

[27] Also, in addition to the premixed gas burner, it is impossible to change a boiler output, in the case that each stage is fixedly partitioned in a burner assembly and a manifold in a conventional multi-step control gas burner.

[28] Also, even in the case that the output of the already-partitioned burner is reduced only by regulating a gas inhalation amount and an air blowing amount, a flowing velocity in a mixer is reduced since a combustion surface area is fixed. As a result, possibilities of incomplete combustion and backfiring are heightened to thus cause a burner combustion feature to become bad.

[29] Meanwhile, in the premixed gas burner which is used for a combustion device such as a gas boiler or hot water supply device, to perform a premixed gas combustion operation, fire hole surfaces having fire holes through which flames are formed are made of ceramic plates, heat-resistant stainless steel plates, or metal fiber mats.

[30] That is, the conventional premixed gas burner includes a fire hole unit where fire holes are formed on a single plate-shaped or cylindrical member, or on a metal fiber mat or ceramic plate member which is fabricated by a knitting or sintering method.

[31] By the way, in the case of the fire hole unit that fire holes are disposed on the single plate-shaped or cylindrical member, the burner combustion surface can be deformed or twisted due to a thermal stress. In severe cases, the fire holes are damaged by a fire to thus cause incomplete combustion and backfiring.

[32] Also, since the ceramic plate and the heat-resistant stainless steel plate has a constant hardness or rigidity in view of their structure, rectification plates can be easily assembled in the burner. However, in the case that the ceramic plate is used as a fire hole unit by a sintering method, condensed water generated in the heat exchanger may fall down to the combustion surface during performing an upward combustion operation. In this case, the surface of the fire hole unit is damaged by water, and fire holes having irregular shapes are formed, to thus cause incomplete combustion to take place.

[33] Also, even in the case that a metal fiber mat fabricated by a knitting method is used as a fire hole unit, a user should pull and assemble metal fibers during assembly of a burner. As a result, fire holes which become large locally or wholly are formed on the metal fiber mat. Accordingly, incomplete combustion or backfiring can occur due to non-uniformity of flames.

[34] In particular, since the metal fiber mat is made of metal fibers by a knitting method, it has flexibility.

[35] Thus, the metal fiber mat should maintain air-tightness so that mixed gas can be burnt only on the surface of the metal fiber mat in the burner. Accordingly, the metal fiber mat relies on welding of edge surfaces assembled with rectification plates in the burner, to thus make a fabrication work complicated.

[36] That is, since the flexible metal fiber mat is put on a mat support guide in the burner and then assembled by welding, the fabrication work becomes complicated and a fabrication precision level is lowered. Also, the flexible metal fiber mat causes sagging.

[37] In the case of the conventional premixed gas burner, burner flames may be un- stabilized when a flame temperature is low. Also, a production cost is increased and difficulties of production of the gas burner are caused. In the case of a home-use gas burner which is designed in a simple structure, a stable control of premixed gas combustion may be difficult somewhat.

[38] Also, in the case that ceramic materials, stainless steel materials, or porous plates of a metal fiber knitted structure are used as the combustion surface material of the premixed gas combustion slits, a premixer for mixing fuel gas and air becomes large in its structure and complicated somewhat, an air blowing resistance is not only increased due to an increase in a pressure loss in the premixer, but also abnormal noise is generated at a high-load area during burning or a main flame the gas burner becomes unstable.

[39] In particular, in the existing premixed gas burner having a tubular shape, it is difficult to prevent deformation such as buckling from occurring due to a thermal stress at the time of excessively running the burner. Also, it is difficult to prevent damage of the burner surface by an overheat and excessive production of nitrogen oxide (NOx) due to heat.

[40] Also, in the case of the conventional premixed gas burner, it is difficult to separately attach a device such as a cooling water tube for cooling a burner at the time of overheating the burner.

[41] Accordingly, a new gas burner improving the above-described problems has been proposed by the same applicant as that of this application.

[42] That is, the same applicant as that of this application proposed a gas burner in a

Korea patent application No. 2002-64496 (its laid-open publication No. 2004-35370 published on April 29, 2004) filed on October 22, 2002, entitled "Premixed gas burner having a cooling water pipe."

[43] As shown in FlGs. 3 and 4, the gas burner disclosed in the above-described same applicant's patent application having separated fire hole units includes a tube-shaped burner 20 in which fire hole units 21 each having a number of fire holes formed at a predetermined distance from one another are disposed on the upper end face thereof, for burning gas and air which are supplied in a mixed state, and a plate-shaped burner 30 which is detachably disposed in loaders 22 formed between the fire hole units 21 formed on the upper end of the tube-shaped burner 20, in which fire hole units 31 having a number of fire holes are disposed.

[44] Also, the gas burner has a main casing 10 on the bottom surface of which an air blower 50 is mounted so that air can be supplied from the air blower 50 through an air inlet 11 formed on the lower portion of the gas burner.

[45] Here, a partition 13 partitioning between the air blower 50 mounted on the bottom of the main casing 10 and the tube-shaped burner 20 is formed at a distance from the bottom surface of the main casing 10. Also, the tube-shaped burner 20 is loaded over the partition 13.

[46] That is, as described above, the premixed combustion gas burner including the tube- shaped burner 20 and the plate-shaped burner 30 is disposed in parallel with each other on the partition 13 provided in the main casing 10.

[47] Also, a number of mixture supply tubes 40 which are inserted into the tube-shaped burner 20 and disposed at a distance from each other are provided in the front surface of the main casing 10 so that gas and air can be mixed and supplied to the tube-shaped burner 20 and the plate-shaped burner 30. Also, Venturi tubes 60 playing a role of mixing gas and air and distributing the mixed flow amount which are needed for combustion of the burner and independently supplied to each burner are installed on the front surface of the mixture supply tubes 40.

[48] The mixture supply tubes 40 play a role of mixing gas and air and supplying the mixture to the burner in a mixture state of gas and air.

[49] Also, manifolders 90 through which air and gas can be supplied are provided in front of each of the Venturi tubes 60. Accordingly a separate unit for mixing air and gas is not needed. Gas is supplied from nozzles closely installed in front of the Venturi tubes 60.

[50] Here, as shown in FlG. 3, in the tube-shaped burner 20 whose front face is opened and inner portion is of a hollow tubular shape, fire hole units 21 each having a number of fire holes formed with a uniform size at a predetermined distance from one another are disposed in both edge lines and the inner portion on the upper end face thereof. Loaders 22 are formed to mount the plate-shaped burner 30 between the fire hole units 21 in turn.

[51] Also, the tube-shaped burner 20 is formed of a number of tubular burners 20 connected in parallel with one another, in units of a single tubular shape.

[52] Here, a plurality of fitting holes 23 through which a cooling water tube 70 is fitted and which is fixedly connected with the plate-shaped burner 30 are formed at a pre¬ determined distance on the lateral surface of the tube-shaped burner 20.

[53] Also, the plate-shaped burner 30 is a burner made of a plate-shaped material on the bottom of which a protruding pin structure 32 is formed with a predetermined curvature.

[54] That is, the plate-shaped burner 30 has a structure that fire hole units 31 are disposed along both edge lines on the upper surface of the plate-shaped material, in which each fire hole unit has a number of fire holes at a predetermined distance in the form of a slit of a uniform size, like the tube-shaped burner 20.

[55] Also, fitting holes 33 formed on the pin-structure 32 formed on the bottom of the plate-shaped burner 30, through which a cooling water tube 70 can penetrate are formed in correspondence to the fitting holes 23 of the tube-shaped burner 20.

[56] That is, when the plate-shaped burner 30 is mounted in the tube-shaped burner 20, the tube-shaped burner 20 and the plate-shaped burner 30 are firmly fixed therebetween, and a cooling water tube 70 through which water circulates to cool the burner is provided, so that deformation such as buckling is prevented from occurring due to a thermal stress existing in the burner during an excessive running of the burner.

[57] That is, the plate-shaped burner 30 is simply fitted into the loader 22 of the tube- shaped burner 20. In this case, the water tube 70 penetrates the insertion hole 12 formed in the lateral surface of the main casing 10 and fitted into a fitting hole 23 formed in the lateral surface of the tube-shaped burner 20 and a fitting hole 33 formed in the pin structure 32 formed on the bottom surface of the plate-shaped burner 30 in correspondence to the fitting hole 23 formed in the tube-shaped burner 20, to thereby firmly fix the tube-shaped burner 20 and the plate-shaped burner 30. As a result, water circulating along the water tube 70 can cool the overheated burner simultaneously.

[58] The tube-shaped burner 20 and the plate-shaped burner 30 having the above- described structures constitute a single premixed combustion gas burner in which the plate-shaped burner 30 is mounted on the loaders 22 of the tube-shaped burner 20.

[59] Here, the fire hole unit 21 of the tube-shaped burner 20 is located in the middle of the plate-shaped burners 30, and the fire hole unit 21 of the tube-shaped burner 20 makes flames easily transmitted between the plate-shaped burners 30. When the tube- shaped burners 20 are connected in parallel with one another, the leftmost and rightmost fire hole units 21 play a role of easily transmitting flames between the tube- shaped burners 20.

[60] The gas burner according to the previous patent application having the above- described structure employs a structure of performing a multi-stage control of a burner in which premixed combustion gas burners each which includes several tube-shaped burners 20 and several plate-shaped burners 30 whose output capacity is identical are disposed in parallel with one another to thereby perform a combustion operation by varying the number of burners according to a desired heat capacity.

[61] In particular, the output of the burner is influenced by the number of the plates where the fire hole units are disposed. Thus, a burner capacity is easily changed according to the number of plates and the size of the fire holes.

[62] Also, since the fire hole units are separated into several pieces, a twisted degree due to thermal expansion is minimized although the burner surface is cumulatively heated, and maintenance of the running performance of the burner is more excellent in comparison with the conventional premixed combustion gas burners.

[63] In other words, since the cooling water tube 70 penetrates the pin structure 32 formed in the lower end of the plate-shaped burner 30, heat generated in the upper fire hole unit 31 is discharged through the pin structure 32 although the burner is overheated. In this case, water is supplied through the cooling water tube 70 to cool the burner. As a result, the gas burner has a merit that deformation such an buckling due to thermal tension caused by overrunning the burner can be prevented.

[64] Also, if the temperature of flames is lowered through a cooling function of the cooling water circulating through the water tube 70, a more amount of nitrogen oxide generated can be reduced and damage by a fire due to heat cumulated on the burner surface can be prevented.

[65] In particular, the cooling water tube 70 plays a role of fixing the tube-shaped burner

20 and the plate-shaped burner 30 when the plate-shaped burner 30 is mounted in the loaders 22 of the tube-shaped burner 20, as well. Disclosure of Invention Technical Problem

[66] However, since the tube-shaped burner 20 and the plate-shaped burner 30 are combined in the previous gas burner, the structure of the fire hole units is complicated. Also, since the separated water tube 70 is used in order to prevent deformation such as buckling from occurring due to thermal stress, an assembly work and a layout structure become complicated. Technical Solution

[67] To solve the above problems, it is an object of the present invention to provide a gas burner of a new structure in which fire hole units in a burner portion are formed of only fire hole plates of a plate shape and thus are simple in their structures and the fire hole units are separated into several pieces, to accordingly prevent deformation due to a thermal stress, and also the size and quantity of fire holes can be easily changed, to thus easily alter a burner heat capacity.

[68] It is another object of the present invention to provide a gas burner in which partitions are used in order to constitute fire hole units of a burner module having an identical burner output range, and thus the position alteration of the partitions is easily performed to accordingly make it easy to change the total output of the burner and to adjust the combustion surface area. Advantageous Effects

[69] As described above, the present invention provides a gas burner in which several fire hole units each having an identical burner output range are disposed in parallel with one another and the number of the fire hole units can be altered according to a required calory, to thereby perform a combustion operation, and the total output alteration is easily performed through change in the position and the number of the partitions and the combustion surface area is easily performed, to thereby allow a multi-stage control of the gas burner.

[70] Also, the fire hole units in the burner portion are formed of only fire hole plates of a plate-shaped material. Accordingly, the structure is simple and the fire hole units are separated into several pieces, to thereby prevent deformation due to a thermal stress. Also, the size and number of the fire holes can be easily changed, and thus the burner capacity can be easily changed.

[71] In particular, several fire hole units each having an identical burner output range are disposed in parallel with one another, and thus the number of burners can be varied according to a required calory. As a result, since the number of unit burners can be changed according to a target calory of a full load, the present invention provides a gas burner capable of a multi-stage control on which a design can be easily altered.

[72] Also, the gas burner according to the present invention has a structure of the typical premixed gas burner, and thus includes the same merits as those of the existing premixed gas burner.

[73] In other words, the total length of the flames is reduced and simultaneously the temperature of the flames is lowered. Thus, a load with respect to an identical area is reduced, and thus production of polluted materials such as carbon monooxide and nitrogen oxide can be minimized.

[74] Also, the gas burner according to the present invention can be easily fabricated into a high-load burner assembly whose size is relatively small than that of the con¬ ventional Bunsen burner, and increase and decrease the number of the unit burners according to a target calory of a total load, to accordingly have a structural feature that alteration of a design can be easily performed. Brief Description of the Drawings

[75] The above and other objects and advantages of the present invention will become more apparent by describing the preferred embodiments thereof in detail with reference to the accompanying drawings in which:

[76] FlG. 1 is a schematic view explaining a conventional Bunsen gas burner which is in use;

[77] FlG. 2 is a cross-sectional view showing an example where a conventional premixed gas burner is used in a boiler device;

[78] FlG. 3 is an exploded perspective view showing a total structure of a conventional premixed gas burner according to a previous patent application;

[79] FlG. 4 is a cross-sectional view showing an assembly state of the premixed gas burner shown in FlG. 3;

[80] FlG. 5 is an exploded perspective view showing a total structure of a gas burner according to the present invention; [81] FlG. 6 is a perspective view showing an assembly state of the gas burner shown in

FIG. 5;

[82] FIG. 7 is a perspective view showing a burner assembly of a gas burner according to the present invention;

[83] FIG. 8 is an exploded perspective view showing essential portions of one fire hole unit according to the present invention;

[84] FIG. 9 is a cross-sectional view showing the internal structure of a burner assembly in a gas burner according to the present invention;

[85] FIG. 10 is a perspective view showing the air discharging mechanism of an air blower according to the present invention;

[86] FIG. 11 is a cross-sectional view showing an example of changing installation angles of partitions according to the air discharging pattern of the air blower shown in FIG. 10 according to the present invention;

[87] FIG. 12 is an exploded perspective view showing a gas burner according to another embodiment of the present invention;

[88] FIG. 13 is a perspective view showing an assembly state of the gas burner shown in

FIG. 12; and

[89] FIG. 14 is a cross-sectional view showing the internal structure of a burner assembly in the gas burner of FlG. 13. Best Mode for Carrying Out the Invention

[90] To accomplish the above object of the present invention, according to an aspect of the present invention, there is provided a gas burner comprising: a burner assembly having an air inhalation unit supplying air for combustion located in the lower portion of the burner assembly in which an air blower is mounted in association with the air inhalation unit; a burner portion which is mounted on the upper combustion surface of the burner assembly in which a number of fire hole units each having a number of fire holes formed at a certain interval burn a mixture of gas and air when the gas mixed with air is supplied; a manifold which is installed in one side of the burner assembly in which a gas nozzle for supplying gas supplied via a gas supply tube is installed; and first and second rectification plates installed between the air inhalation unit and the combustion surface in the burner assembly, wherein the fire hole units are formed in the form of a module in which fire hole plates formed of a plate shape where a number of fire holes are formed are connected in parallel with each other, wherein when the fire hole units are mounted in the burner portion, the total fire hole units are separated into a number of pieces, and wherein several fire hole units each having an identical burner output range are disposed in parallel with each other, to thereby perform a combustion operation by changing the number of fire hole units according to a desired heat capacity. [91] Here, the fire hole plates constituting the fire hole units each have a structure that fire holes are uniformly formed on the upper end surface of a π

-shaped plate member and simultaneously a number of grooves are formed at a certain interval on the left and right side surfaces excluding the upper end surface on which the fire holes are formed, to thereby easily vary size of the fire hole and the number of fire hole plates constituting the fire hole units.

[92] Also, in the case that the fire hole units are applied in a premixed gas burner im¬ plementing a multi-stage control, performance of each stage in the burner is uniformly implemented using the uniformly formed fire holes.

[93] In particular, a number of fixing units are installed on the combustion surface of the burner assembly at a certain interval according to the number of fire hole units and the mounting positions, and when partitions are installed via the fixing units, the partitions partitioning each stage over from the lower air inhalation unit to the upper combustion surface in the burner assembly are detachably installed.

[94] Here, when each stage is partitioned by installing the partitions according to the number of the fire hole units, an installation angle of each partition is adjusted to control a cross-sectional area of the air inhalation unit of each stage, to thereby supply a uniform amount of air.

[95] Also, when an output of the burner is altered by reducing the number of the fire hole units, the number of the partitions is reduced according to the number of the reduced number of the fire hole units, and simultaneously part of the combustion surface of the fire hole units is closed using a plate member on which fire holes are not formed, to thereby maintain a fire hole load per a unit area in each fire hole unit to be consistent. Mode for the Invention

[96] Hereinbelow, a gas burner according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings. Like reference numerals denote like elements through the following embodiments.

[97] FlG. 5 is an exploded perspective view showing a total structure of a gas burner according to the present invention. FlG. 6 is a perspective view showing an assembly state of the gas burner shown in FlG. 5. FlG. 7 is a perspective view showing a burner assembly of a gas burner according to the present invention. FlG. 8 is an exploded perspective view showing essential portions of one fire hole unit according to the prese nt invention. FlG. 9 is a cross-sectional view showing the internal structure of a burner assembly in a gas burner according to the present invention. [98] FlG. 10 is a perspective view showing the air discharging mechanism of an air blower according to the present invention. FlG. 11 is a cross-sectional view showing an example of changing installation angles of partitions according to the air discharging pattern of the air blower shown in FlG. 10 according to the present invention.

[99] Referring to FlGs. 5 through 7, a gas burner according to the present invention includes a burner assembly 100 supplying air for combustion in which an air blower 130 is mounted in the lower portion of the burner assembly 100, and a burner portion 110 which is mounted on the upper combustion surface of the burner assembly 100 in which a number of fire hole units 120 each having a number of fire holes 122 disposed at a certain interval burn a mixture of gas and air when the gas mixed with air is supplied.

[100] The gas burner is a kind of a premixed gas burner that mixes fuel gas supplied from a gas supply tube 150 with primary air for combustion compulsively supplied by an air blower 130, to thereby form premixed gas, and supplies the premixed gas to the burner portion 110 in which a number of fire hole units 120 each having a number of fire holes 122 are disposed at a certain interval, to thereby burn the premixed gas.

[101] Also, the burner portion 110 having a number of separated fire hole units 120 and a number of gas supply units 142 are provided. Accordingly, the present invention provides a gas burner that executes an overall combustion operation and a partial combustion operation to thereby perform a multi-stage control.

[102] In other words, the gas burner according to the present invention includes the burner portion 110 in which a number of fire hole units 120 each having a number of fire hole plates 121 are disposed in parallel with each other in the upper end of the burner assembly 100. The air blower 130 is mounted in the lower end of the burner assembly 100, so that combustion air can be supplied linearly. An integral manifold 140 is installed in front of the burner assembly 100 in which gas supply units 142 connected with a gas supply tube 150 are provided.

[103] Here, the burner portion 110 has a structure of burning gas mixed with air when the mixture of gas and air is supplied, in which a set of fire hole units 120 each having a number of fire holes 122 are disposed at a certain distance on the combustion surface of the burner assembly 100 so that the entire fire hole units 120 can be separated in¬ dividually.

[104] Here, referring to FlG. 8, the fire hole units 120 are formed of a set of several fire hole plates 121 each having a π

-shaped plate, in which a number of fire hole plates 121 each having a number of fire holes 122 at a certain interval along the upper inner surface, and each formed into a uniform size are disposed in parallel with each other.

[105] That is, the burner portion 110 has a structure that a number of fire hole units 120 having a plate-shaped unit are connected and disposed in parallel with each other.

[106] In particular, a number of fire holes 122 constituting the fire hole units 120 are formed uniformly on the fire hole plates 121, to thereby provide a uniform performance of a unit of a burner.

[107] Of course, size of each of the fire holes 122 can be formed on the fire hole plates

121 in various forms according to a desired design.

[108] Accordingly, the fire hole plates 121 are disposed in combination according to size of each of the fire holes 122, to thereby constitute the fire hole units 120 having a variety of fire hole loads.

[109] Also, a number of grooves 121a are formed at a certain interval on the left and right side surfaces excluding the upper end surface on which the fire holes 122 are formed in the fire hole plates 121, to thereby minimize a degree of twist due to a thermal stress.

[110] In particular, the fire hole units 120 are constituted in the form of a single module including several fire hole plates 121 having the above-described structure, to thereby cause the entire fire hole units 120 to be disposed in a structure that the whole fire hole units 120 are separated into a number of pieces in the gas burner. This functions as a factor that can minimize a degree of twist due to a thermal stress even in the case that the surfaces of the fire hole units 120 are cumulatively heated due to an abnormal combustion operation in the fire hole units 120.

[Ill] Thus, in comparison with the existing premixed gas burner which is well known and used, the gas burner according to the present invention has a relatively remarkable effect of maintaining a uniform running performance of the burner.

[112] Also, since the fire hole units 120 are fabricated into a module and separated in¬ dividually, the number of fire hole units 120 can be mounted in combination considering the maximum output capacity of a gas burner according to a desired design.

[113] This means that the maximum output capacity of a gas burner is determined according to the number of the fire hole units 120 which are mounted in the gas burner.

[114] As described above, the fire hole units 120 each have a structure that size of the fire holes 122 and the number of the fire hole plates 121 in the fire hole units 120 are easily changed according to a required output range, that is, a capacity alteration, to thereby allow the stage adjustment as well as the capacity alteration to be easily performed.

[115] Meanwhile, as shown in FlGs. 7 and 9, the burner assembly 100 has an internal structure that an air flowing path is gradually widened in the front and rear direction and the left and right direction so that the air flowing path is formed in the vertically upward direction having no curved portions from the air inhalation unit 102 to the combustion surface 103.

[116] As described above, an eddy production structure and a flowing path curve are not formed in order to form a mixer in the burner assembly 100, to accordingly exclude a flow resistance and to thus minimize a pressure loss.

[117] Of course, a sufficient distance or space should be assumed between the air inhalation unit 102 and the combustion surface 103 so that gas and primary air for combustion can be sufficiently premixed.

[118] Also, first and second rectification plates 190 and 191 for uniformly mixing gas and combustion air are provided in the burner assembly 100. Also, partitions 200 are formed in the burner assembly 100 in order to uniformly distribute the premixed gas with air.

[119] Here, the first rectification plate 190 is installed toward the air inhalation unit 102 and has a plate shape, in which a number of throughholes 190a through which primary air passes are formed at the center of the first rectification plate 190.

[120] Also, the second rectification plate 191 is installed just below the fire hole units 120 and has a plate shape, in which a number of small throughholes 191a of which the sizes are relatively smaller than those of the throughholes 190 in the first rectification plate 190 are formed uniformly over the whole second rectification plate 191.

[121] Thus, the primary air for combustion which is input via the air inhalation unit 102 collides with the first rectification plate 190 and is mixed with gas supplied from the gas nozzle 170 to be described later at the state where the primary air is sufficiently rectified via the throughholes 190a.

[122] Also, the primary air for combustion and the gas having passed through the first rectification plate 190 are input into the second rectification plate 191 at the state where the primary air and the gas are premixed via a sufficient distance or space assumed on the flowing path in the burner assembly 100, and the premixed gas which has been sufficiently mixed via the first rectification plate 190 is uniformly distributed by the small holes 191a, so as to be guided to the fire hole plates 121 in the fire hole units 120.

[123] Meanwhile, the present invention is characterized in that partitions 200 are installed in the burner assembly 100 in order to uniformly the premixed gas as described above together with the first and second rectification plates 190 and 191.

[124] That is, as shown in FlGs. 7, 9 and 11, the partitions 200 are fitted or loaded into a number of fixing grooves 104 which are provided at a certain distance near the combustion surface 103 of the burner assembly 100, to thus play a role of partitioning the internal space of the burner assembly 100 into a number of compartments.

[125] In other words, the partitions 200 partitions the space in the burner assembly 100 between the air inhalation unit 102 and the combustion surface 103, considering the number of the fire hole units 120 mounted on the combustion surface 103 in the burner assembly 100, so that the internal space of the burner assembly 100 is partitioned in a multi-stage in correspondence to the number of the fire hole units 120. Accordingly, the premixed gas can be uniformly dispersed and supplied into the fire hole units 120 which have been respectively separated according to each partitioned stage.

[126] The partitions 200 can be supported and fixed to a number of the fixing grooves

104 which are formed on the combustion surface 103 at a certain interval, to thus make it easy to alter the positions of the partitions 200.

[127] Of course, the interval between the fixing grooves 104 are designed in advance according to the number of the fire hole units 120 mounted on the combustion surface 103 and the mounting position thereof.

[128] Thus, when the overall output of the gas burner is determined or the output alteration is requested, the number of the fire hole units 120 is determined. If the mounting positions of the fire hole units 120 are determined according to the number of the determined fire hole units 120, the installation numbers and installation positions of the partitions 200 partitioning each stage are determined.

[129] Meanwhile, when the primary air for combustion necessary for supplying premixed gas to the fire hole units 120, and the air blower 130 is used, which is installed below the burner assembly 100 for discharging air vertically upwards, as shown in FlG. 10, an amount of air discharged from the air blower 130 is not uniform all over the exit cross-sectional area due to the structural features of the air blower 130. Instead, the amount of too much air discharged from the air blower 130 is given to a particular area, for example, an area "A" of FlG. 10. Accordingly, an amount of air may not be uniformly supplied to each stage of the fire hole units 120 in the burner portion 110.

[130] Also, since a distance from the air discharging outlet of the air blower to the first rectification plate 190 attached to the lower end of the partitions 200 is approximately 25mm in the case of the gas burner according to the preferred embodiment of the present invention, an irregular amount of air discharged from the outlet of the air blower 130 is not sufficient to be supplied with an average value to each stage.

[131] Thus, an offset of an amount of air should be corrected according to an area where air is discharged from the air blower 130. Otherwise, a combustion performance of each stage differs from each other.

[132] In particular, an amount of gas of the gas and air forming the premixed gas is uniformly supplied through a valve control which can control an amount of gas when gas is ejected via a gas nozzle 170 to be described later via the gas supply tube 150. Accordingly, if an air ratio of each stage in the burner should be uniformly maintained, an amount of air supplied should be same, that is, should be uniformly supplied.

[133] Therefore, in the case of the gas burner according to the present invention which maintains the combustion performance of each stage identically, as shown in FlG. 11, it is preferable that the entrance cross-sectional area of each stage in the fire hole units 120 is adjusted so that an area "b" where a large amount of air is discharged from the air blower 130 becomes narrow and an area "a" where a small amount of air is discharged from the air blower 130 becomes wide through an installation structure of the partitions 200; 200a and 200b, to thereby supply a uniform amount of air to each stage in the burner.

[ 134] In particular, in addition to a method of adjusting the installation angles of the partitions 200a and 200b partitioning each stage in the burner, the number of throughholes 190a which are formed in uniform size in the first rectification plate 190 is adjusted, or a method of disposing throughholes 190a of different sizes can be used in order to adjust the cross-sectional area of the air inhalation unit 102. Also, the above-described methods can be simultaneously used in parallel with one another.

[135] That is, in the case that the throughholes 190a of the first rectification plate 190 are uniformly formed, a relatively small number of the throughholes 190a are formed in an area "b" where a large amount of air is discharged from the air blower 130 in comparison with an area "a" where a small amount of air is discharged from the air blower 130. Otherwise, in the case that a different size of the throughholes 190a of the first rectification plate 190 are disposed, a relatively small size of the throughholes 190a are formed in an area "b" where a large amount of air is discharged from the air blower 130 in comparison with an area "a" where a small amount of air is discharged from the air blower 130.

[136] Meanwhile, referring to FlG. 5 showing the first preferred embodiment of the present invention, three gas supply unit 142 are formed in parallel. A gas supply tube 150 is connected with the central gas supply unit 142, and the left and right gas supply units 142 are connected with solenoid valves 160 in association with the gas nozzles 170 via an opened portion, respectively

[137] The three gas supply units 142 communicate with one another via lateral connection holes 143 which are formed on the lateral walls adjacent in the gas supply units 142. Accordingly, if gas is supplied from the gas supply tube 150 connected with the central gas supply unit 142, gas is also distributed to the left and right gas supply units 142.

[138] The gas supply from the central gas supply unit 142 to both the lateral gas supply units 142 is selectively performed via opening and closing of the solenoid valves 160.

[139] An opening and closing hole 161 formed in the body of the solenoid valve 160 and lateral connection holes 143 formed in the lateral walls of the gas supply units 142 are correspondingly opposed to one another. As a result, when the opening and closing hole 161 formed in the body of the solenoid valve 160 is opened and closed by the function of the solenoid valve 160, to thereby determine whether or not gas is supplied. [140] When a multi-stage control is executed using the gas burner according to the present invention, a function of adjusting an amount of gas supplied is provided in the present invention.

[141] The gas nozzle 170 is connected with the solenoid valve 160, so that gas can be supplied. At the state where the gas nozzle 170 is connected to the solenoid valve 160, the gas nozzle 170 is extensively installed so that it is placed on the air supply path of the air blower 130 via the gas supply units 142. Accordingly, the combustion air discharged from the air blower 130 and the gas supplied via the gas nozzles 170 are mixed in the burner assembly 100 and the premixed gas is supplied to the fire hole units 120.

[142] In particular, when the gas supply units 142 are connected with the gas supply tube

150, gas and air for combustion are premixed in the process of passing though the internal air inhalation unit to the combustion surface in the burner assembly 100, at the state where the gas supply units 142 take the independent shapes from the air supply path of air for combustion supplied via the air blower 130.

[143] Meanwhile, an orifice 180 which can control an amount of flowing gas is installed between the solenoid valves 160 and the gas nozzles 170 which are installed in the manifold 140. In this case, only the orifice 180 can be replaced without replacement of the gas nozzles 170 in the case that a calorie change is needed from LNG to LPG and vice versa according to the kind of gas used, to thereby make it possible to perform a calorie change.

[144] Here, an O-ring 162 for use in a valve and a packing 163 for use in a valve seat are intermediated between the solenoid valve 160 and the orifice 180.

[145] As described above, a manifold 140 is provided in the present invention so that air and gas can be supplied separately via the independent paths in the gas burner according to the present invention. The gas nozzles 170 playing a role of distributing gas necessary for combustion can be mounted in the manifold 140.

[146] Here, gas is supplied from the gas supply tube 150 connected toward the gas supply units 142 installed in the body of the manifold 140.

[147] That is, gas supplied from the gas supply tube 150 via the gas supply units 142 is distributed into the internal space of the burner assembly 100 via the gas nozzles 170, in the manifold 140. The air supplied from the air blower 130 is supplied into the burner assembly 100 and passes through the internal space of the burner assembly 100. At this process, the air passes through the first and second rectification plates 190 and 191 and thus air and gas is mixed and thus premixed gas is supplied to the burner portion 110 in the form of a mixture.

[148] Here, when a set of fire hole units 120 constituting the burner portion 110 which are supported and loaded via the fixing grooves 101 formed on the combustion surface 103 in the burner assembly 100 are installed in the present invention, a gap between the fire hole units 120 which can occur due to a working clearance and an assembly clearance is minimized, to thereby prevent a leakage of the mixture of gas and air. Also, fire hole unit supporting guides 125 are supported at the left and right sides of the fire hole units 120 in order to minimize deformation of the fire hole units 120 which can occur during performing abnormal combustion in the fire hole units 120.

[149] Here, the fire hole unit supporting guides 125 are provided to have lengths cor¬ responding to those of the fire hole plates 121 of the fire hole units 120, and disposed in parallel with each other at both the sides of the fire hole plates 121.

[150] In particular, as shown in FlGs. 8 and 9, the fire hole unit supporting guides 125 which are installed at the left and right sides of the fire hole units 120 are installed with a sufficient gap "h" so as to assume a space of absorbing an expansion amount in the case that the fire hole units 120 are thermally expanded to the left and right sides.

[151] Also, the fire hole units 120 are firmly fixed together with the fire hole unit supporting guides 125, in order to prevent a leakage of the mixture of gas and air, and fire hole unit fixing covers 123 are provided at the left and right sides of the fire hole units 120, respectively.

[152] That is, both the sides of the fire hole units 120 which is implemented into a single set of the fire hole plates 121 are fixed using fire hole unit fixing covers 123 each formed of a thin plate and bolts 124.

[153] Here, the fire hole unit fixing covers 123 each have a substantially D-shaped member, on which bolt holes 123a are formed through which bolts are tightened.

[154] The fire hole unit fixing covers 123 are separately fixed respectively according to the set of fire hole units 120, to thereby minimize deformation due to a thermal stress.

[155] Also, the fire hole fixing covers 123 can minimize the gap between the fire hole units 120 which can occur due to a fabrication clearance or an assembly clearance when the fire hole units 120 constituted by a number of fire hole plates 121, to thereby prevent a leakage of the mixture of gas and air.

[156] Meanwhile, referring to FlGs. 5 and 6 showing an embodiment of the gas burner according to the present invention, three fire hole units 120 are disposed in parallel with one another. However, the present invention is not limited thereto, but it is apparent to one skilled in the art that the number of fire hole units is changed according to a desired thermal energy, to thereby perform a burning operation differently.

[157] That is, FlG. 12 is an exploded perspective view showing a gas burner according to another embodiment of the present invention. FlG. 13 is a perspective view showing an assembly state of the gas burner shown in FlG. 12. FlG. 14 is a cross-sectional view showing the internal structure of a burner assembly in the gas burner of FlG. 13.

[158] As shown in FlGs. 12 through 14, a gas burner according to another embodiment of the present invention has a structure including two fire hole units 120.

[159] In the case that the gas burner includes two fire hole units 120, the maximum output thereof is smaller than that of the case that the gas burner includes three fire hole units 120.

[160] In particular, as shown in FlG. 13, part of the combustion surface is closed using fire hole plates 121 ' on which fire holes 122 are not formed because of reduction in an area of the combustion surface due to the output reduction.

[161] This is to maintain a fire hole load with respect to a unit area of the combustion surface consistently and thus exhibit an identical performance in different gas burners having respectively different outputs.

[162] As shown in FlGs. 12 and 13, only two gas supply units 142 are provided for the two fire hole units 120.

[163] That is, in the case of the gas burner having three fire hole units 120 according to an embodiment of the present invention, three gas supply units 142 are provided as described above, in which the gas supply tube 150 is connected with the central gas supply unit 142 and the left and right gas supply units 142 are selectively opened and closed using the solenoid valves 160. However, in the case of the gas burner having two fire hole units 120, the central gas supply unit 142 is closed, and the gas supply tube 150 and the solenoid valve 160 are connected with the left and right two gas supply units 142, respectively. Accordingly, gas supply can be selectively controlled.

[164] Also, as shown in FlG. 14, one partition 200 which plays a role of uniformly dis¬ tributing the mixture is installed between the two fire hole units 120 in the burner assembly 100.

[165] As described above, the gas burner according to the present invention has a con¬ figuration capable of a multi-stage control in the gas burner, in which several fire hole units 120 each having an identical burner output range are disposed in parallel with one another and the number of fire hole units 120 are altered according to a desired calory to thereby perform a different combustion operation.

[166] Also, since the gas burner according to the present invention has a structure of a typical premixed gas burner, the merits of the existing premixed gas burner are maintained as they are.

[167] In other words, the total length of the flames is reduced and simultaneously the temperature of the flames is lowered. Thus, a load with respect to an identical area is reduced, and thus production of polluted materials such as carbon monooxide and nitrogen oxide can be minimized.

[168] Also, the gas burner according to the present invention can be easily fabricated into a high-load burner assembly whose size is relatively small than that of the con¬ ventional Bunsen burner, and increase and decrease the number of the unit burners according to a target calory of a total load, to accordingly have a structural feature that alteration of a design can be easily performed.

[169] As described above, the fire hole units in the present invention are implemented so that the size of the fire holes and the number of the fire hole plates can be easily altered according to a required output range, that is, a capacity change. Thus, the present invention can easily alter the capacity of a burner and easily adjust a combustion stage to thereby easily implement a multi-stage control.

[170] As described above, the present invention has been described with respect to par¬ ticularly preferred embodiments. However, the present invention is not limited to the above embodiments, and it is possible for one who has an ordinary skill in the art to make various modifications and variations, without departing off the spirit of the present invention. Thus, the protective scope of the present invention is not defined within the detailed description thereof but is defined by the claims to be described later and the technical spirit of the present invention. Industrial Applicability

[171] As described above, a gas burner according to the present invention can be applied to a premixed gas burner which is used for a gas boiler.

[172]

Claims

[ 1 ] A gas burner comprising : a burner assembly having an air inhalation unit supplying air for combustion located in the lower portion of the burner assembly in which an air blower is mounted in association with the air inhalation unit; a burner portion which is mounted on the upper combustion surface of the burner assembly in which a number of fire hole units each having a number of fire holes formed at a certain interval burn a mixture of gas and air when the gas mixed with air is supplied; a manifold which is installed in one side of the burner assembly in which a gas nozzle for supplying gas supplied via a gas supply tube is installed; and first and second rectification plates installed between the air inhalation unit and the combustion surface in the burner assembly, wherein the fire hole units are formed in the form of a module in which fire hole plates formed of a plate shape where a number of fire holes are formed are connected in parallel with each other, wherein when the fire hole units are mounted in the burner portion, the total fire hole units are separated into a number of pieces, and wherein several fire hole units each having an identical burner output range are disposed in parallel with each other, to thereby perform a combustion operation by changing the number of fire hole units according to a desired heat capacity.

[2] The gas burner according to claim 1, wherein the fire hole plates constituting the fire hole units each have a structure that fire holes are uniformly formed on the upper end surface of a π

[3] The gas burner according to claim 1 or 2, wherein in the case that the fire hole units are applied in a premixed gas burner implementing a multi-stage control, performance of each stage in the burner is uniformly implemented using the uniformly formed fire holes.

[4] The gas burner according to claim 2, wherein a structure of grooves in the left and right surfaces in the fire hole plates plays a role of a cooling fin to minimize a structural damage such as thermal deformation due to a temperature rise and overheat of the fire hole units by combustion at high temperature.

[5] The gas burner according to claim 1, wherein a number of fixing units are installed on the combustion surface of the burner assembly at a certain interval according to the number of fire hole units and the mounting positions, and when partitions are installed via the fixing units, the partitions partitioning each stage over from the lower air inhalation unit to the upper combustion surface in the burner assembly are detachably installed.

[6] The gas burner according to claim 5, wherein when each stage is partitioned by installing the partitions according to the number of the fire hole units, an in¬ stallation angle of each partition is adjusted to control a cross-sectional area of the air inhalation unit of each stage, to thereby supply a uniform amount of air.

[7] The gas burner according to claim 5 or 6, wherein when an output of the burner is altered by reducing the number of the fire hole units, the number of the partitions is reduced according to the number of the reduced number of the fire hole units, and simultaneously part of the combustion surface of the fire hole units is closed using a plate member on which fire holes are not formed, to thereby maintain a fire hole load per a unit area in each fire hole unit to be consistent.

[8] The gas burner according to claim 6, wherein the number of holes which are formed in uniform size in the first rectification plate or holes each having different size are disposed in the first rectification plate, to thereby make a uniform amount of air supplied to each stage.

[9] The gas burner according to claim 7, wherein the number of stages of the burners is changed according to a user's necessity, to thereby make use of a one-stage burner without using any partitions.