WO2010031174A2

WO2010031174A2 - Burner

Info

Publication number: WO2010031174A2
Application number: PCT/CA2009/001308
Authority: WO
Inventors: Darsell Karringten; William Kelly
Original assignee: Darsell Karringten; William Kelly
Priority date: 2008-09-22
Filing date: 2009-09-22
Publication date: 2010-03-25
Also published as: EP2334985A2; RU2011115779A; US20100154771A1; RU2011115778A; RU2507447C2; EP2334985A4; AU2009295221A1; CN104197331A; CN102224379B; RU2509955C2; WO2010031174A3; EP2338000A4; US20100167222A1; WO2010031175A1; AU2009295222A1; CN102224378B; CN104197331B; CN102224379A; CN102224378A; WO2010031176A1

Abstract

A fuel nozzle for use in a burner comprises a main body having an inlet end and an outlet end and defining a longitudinal axis. A fuel passageway has a fuel receiving inlet, and a fuel emitting outlet for delivering fuel to a mixing chamber of the burner. A first air flow channel having an inlet, and an outlet disposed adjacent the fuel emitting outlet for delivering air to the mixing chamber. The portion of the first air flow channel adjacent the outlet is oriented obliquely to the longitudinal axis. A second air flow channel has an in let, and an outlet disposed adjacent the fuel emitting outlet for delivering air to the mixing chamber. The first air flow channel and the second air flow channel generally surround the fuel passageway, and are disposed on the exterior of the main body.

Description

BURNER

FIELD OF THE INVENTION

[0001 ] This application is a non-provisional application claiming priority to United States provisional patent application Serial No, 61/099,200 filed on September 22, 2008.

FIELD OF THE INVENTION

[0002] The present invention relates to burners, and more particularly to burners that mix air or oxygen with a gaseous or evaporated fuel.

BACKGROUND OF THE INVENTION

[0003] Burners that use gaseous fuel or liquid fuel are used in many applications including boilers, line heaters, furnaces, other gas fired appliances, and in many others. Basically, these burners introduce a gaseous fuel or liquid fuel into a stream of air or oxygen. If liquid fuel is used, it must be vapourized or atomized first. The resulting flow of fuel and air or oxygen is ignited and exits the nozzle of the burner either as a visible flame or as a stream of an extremely hot gaseous mixture.

[0004] Tn an att empt to improve the state of the art units in various applications, such as boilers, line heaters, furnaces, and other gas fired appliances, a detailed study was conducted to qualify and quantify the state of the art in each of these above stated fields. The study indicated that without exception, improvements could be made in each of these areas, especially in terms of reduction of operational costs, and reduction or elimination of emissions. In present world markets, operational costs and environmental concerns, such as reduction or elimination of emissions, are typically two of the most significant issues, if not the most significant issues faced by most businesses. [0005] Interestingly, it is readily apparent in the prior art that the possible improvements that could be made to these various types of devices utilizing burners to produce heat, would not lead to a significantly improved end result. It is also readily apparent that, without exception, the fundamental problem in these various types of devices was that of burner inefficiency. Most prior art burners are only about 60% to 70% efficient. Inefficient combustion of fuel was the main problem inherent with all of these devices. Moreover, this problem of inefficiency of combustion is the major cause of the two above mentioned significant costs in business, namely operational costs and environmental concerns,

[0006| Accordingly, in order to fundamentally improve devices such as boilers, line heaters, furnaces, and other gas fired appliances, it has been found that it is necessary to make significant and primary advances to the design of the burners technology. More specifically, in order to maximize the design of boilers, line heaters, furnaces, and other gas fired appliances, in terms of cost, efficiency, and so on, it is necessary to fundamentally re-design the burners that power them. There is no sense in improving boiler technology, line heater technology, furnace technology, and so on, if the burners used in them are prohibitively inefficient.

[0007] It is interesting to note that such improvements to various types of burners have been attempted for many years in various areas without significant success. Accordingly, other types of improvements to burner systems and devices that employ burners are commonly used.

[0008| The most common design improvement used to overcome the environmental problem of emissions is to recirculate exhaust gases In general, it has been found that recirculation of the exhaust gases can be used to decrease the overall emissions of a burner system. There are, however, problems associated with such recirculation of the exhaust gases. The most significant problem is that the recirculation of exhaust gases substantially increases the energy required for passing the mixture flow of combustion air and added exhaust gas through the system. For example, an increase often percent (10%) of exhaust gas recirculation from the exhaust back to the burner typically results in about a 40% to 45% increase in the required power of the fan that forces air into the burner system. Obviously, this is an attempt at a solution that is less than acceptable in terms of efficiency, and therefore cost. This is especially true considering most exhaust gases are passed through the burner system several times. [0009] There are also burner systems that use energy from high velocity combustion air jets to promote recirculation within the burner system. The effectiveness of this technique depends on many factors, and typically it is more difficult to return a substantial portion of combustion products back to the burner if this technique is used, thus making it difficult to employ in many situations.

[00010| It is clear that recirculating exhaust gases in order to improve emissions is not a viable solution to improving the design of burner systems. Burning fuel as efficiently as possible with one pass through the burner system is the only sensible solution; however, desirably efficient burners do not exist.

[00011 ] Only a fundamental re-design of burners and burner technology will produce an efficient burner that produces low emissions. The fundamental technology of burners has not changed significantly in the last several decades. A search of the prior art has revealed two examples of burners that are known to be relatively effective in terms of efficiency and emissions, but not as efficient as the subsequently discussed present invention.

[00012| United States Patent No. 7,484,956 issued February 3, 2009, to Kobayashi et al., discloses Low NOx combustion using cogenerated oxygen and nitrogen streams. The combustion of hydrocarbon fuel is achieved with less formation of NOx by feeding the fuel into a slightly oxygen-enriched atmosphere, and separating air into oxygen-rich and nitrogen-rich streams which are fed separately into the combustion device.

[00013] United States Patent No. 7,429, 173 issued September 30, 2008, to Lanary et aL, discloses a gas burner for use in a furnace and a method of burning gas in a furnace, especially but not exclusively a process furnace used in an oil cracking or refining process. The gas burner comprises two passageways with adjacent outlets. The first passageway is in fluid communication with a source of pressurised fuel gas and has an aperture through which recirculated flue gas can eater the first passageway and the second passageway is in fluid communication with a source of air. In operation, fuel gas is injected into the first passageway and recirculated flue gas is thereby drawn into the first passageway so that it mixes with the fuel gas. Fuel gas is partially combusted and a mixture of partially combusted fuel gas and recirculated flue gas flows up the first passageway and comes into contact with air from the second passageway and combusts. The use of recirculated flue gas keeps down the level of NOx emissions and as the recirculated flue gas is sucked into the first passageway by the pressurised fuel gas flow, it is not necessary to provide complex pumping mechanisms.

[00014] United States Patent No. 7,422,427 Issued September 9, 200S, to Lifshits, discloses an Energy Efficient

Low NOX Burner and Method of Operating Same. The burner is for installation in a furnace having a mixing chamber defined by at least a furnace front wall, two side walls, a top wall and a bottom wall as well as heat transfer pipes through which a heat transfer medium flows and which are arranged on at least one of the top, bottom and side walls. The burner assembly is mounted to the furnace front wall and has a tubular member with an open distal end that is located inside the mixing chamber. The other end of the tubular member is attached to the furnace front wall. Several combustion air ports extend into the tubular member from the other proximal end thereof, and are coupled to a source of combustion air. Several fuel gas discharge; nozzles also extend into the tubular member from the other end thereof and are coupled to a fuel source. Furnace gas openings formed in the tubular member are spaced apart from the distal end, are arranged about the tubular member's periphery, and are located relative to the mixing chamber so that furnace gases circulate past some of the heat transfer pipes before they reach the furnace gas openings to thereby form a mixture of combustion air, fuel gas and furnace gas. A spinner at the distal end of the tubular member creates a recirculation zone fbr the mixture downstream of the spinner and the tubular member.

[0001 5] United States Patent No.6,485,289 issued November 26, 2002, to Kelly, etal., discloses an Ultra Reduced NOx Burner System and Process. Fuel Modification Fuel Rich Reactor (FMFRR) zone gases are brought together with products from a Fuel Lean Reactor (FMR) zone in a low temperature burnout and NOx reduction reactor zone. The fuel modification fuel rich reactor stabilizes combustion through recirculation of hot gases to the reactants. Nitrogenous species decay reactions in the fuel rich zone controls the production ofNOx. The nitrogenous species from the fuel rich zone and the MOx from the fuel lean zone then react in the burnout zone at an. optimal temperature and nitrogenous species mix where NOx is minimized. Temperature Ln all zones, and in particular the burnout zone, can be controlled by furnace gas entrainment, induced flue gas recirculation, forced flue gas recirculation and active cooling by radiative and/or convective heat transfer. NOx can be even further reduced by introducing ammonia, or a like ammo species, into the low temperature burnout zone. By balancing combustion and emissions control reactions over several zones, low emissions can be achieved under good flame stability, turndown, heat transfer and noise characteristics. [00016] It is an object of the present invention to provide a fuel nozzle for use in a burner, wherein the fuel nozzle causes the burner Io burn fuel very efficiently.

[00017] It is another object of the present invention to provide a fuel nozzle for use in a burner, wherein the fuel nozzle causes the burner to produce minimal unwanted emissions.

1000181 It is a further object of the present invention to provide a fuel nozzle for use in a burner, wherein the fuel nozzle and burner can be used with various types of gaseous and liquid fuels.

[00019] It is a further object of the present invention to provide a fuel nozzle for use in a burner, wherein the fuel nozzle and burner are cost effective.

SUMMARY OF THE INVENTION

[00020] In accordance with one aspect of the present invention there is disclosed a novel fuel nozzle for use in a burner. The fuel nozzle comprises a main body having an inlet end and an outlet end and defining a longitudinal axis extending between the inlet end and the outlet end. A fuel passageway has a fuel receiving inlet, and a fuel emitting outlet for delivering fuel to a mixing chamber of the burner. A first air flow channel has an inlet, and an outlet disposed adjacent the fuel emitting outlet for delivering air to the mixing chamber. The portion of the first air flow channel adjacent the outlet is oriented obliquely to the longitudinal axis.

[00021 ] In accordance with another aspect of the present invention there is disclosed a novel fuel nozzle tor use in a burner. The fuel nozzle comprises a main body having an inlet end and an outlet end and defining a longitudinal axis extending between the inlet end and the outlet end. A fuel passageway has a fuel receiving inlet, and a fuel emitting outlet for delivering fuel to a mixing chamber of the burner. A first air flow channel is disposed on the exterior of the elongate main body, and has an inlet, and an outlet disposed adjacent the fuel emitting outlet for delivering air to the mixing chamber. [00022] In accordance with yet another aspect of the present invention there is disclosed a novel fuel nozzle for use in a burner. The fuel nozzle comprises a main body having an inlet end and an outlet end and defining a longitudinal axis extending between the inlet end and the outlet end A fuel passageway has a fuel receiving inlet, and a fuel emitting outlet for delivering fuel to a mixing chamber of the burner. A first air flow channel has an inlet, and an outlet disposed adjacent the fuel emitting outlet tor delivering air to the mixing chamber. A second air flow channel has an inlet, and an outlet disposed adjacent the fuel emitting outlet for delivering air to the mixing chamber. The first air flow channel and the second air flow channel generally surround the fuel passageway.

[00023] Other advantages, features and characteristics of the present invention, as well as methods of operation and functions of the related elements of the structure, and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following detailed description and the appended claims with reference to the accompanying drawings, the latter of which is briefly described herein below.

BRIEF DESCRIPTION OF THE DRAWINGS

[00024] The novel features which are believed to be characteristic of the burner according to the present invention, as to its structure, organization, use and method of operation, together with further objectives and advantages thereof, will be better understood from the following drawings in which a presently preferred embodiment of the invention will now be illustrated by way of example. It is expressly understood, however, that the drawings are for the purpose of illustration and description only, and are not intended as a definition of the limits of the invention. In the accompanying drawings:

[00025] Figure 1 is a perspective view of the first preferred embodiment of the burner according to the present invention;

[00026] Figure 2 is an exploded perspective view of the first preferred embodiment of the burner of Figure 1 ;

[00027] Figure 3 is a left side elevational view of the first preferred embodiment of the burner of Figure 1 ; [ 00028 ] Figure 4 is a right side elevationai view of the first preferred embodiment of the burner of Figure 1 ;

[00029] Figure 5 is a top plan view of the first preferred embodiment of the burner of Figure 1 ;

[00030] Figure 6 is a bottom plan view of the first preferred embodiment of the burner of Figure I ;

[00031 ] Figure 7 is a front elevationai view of the first preferred embodiment of the burner of Figure 1 ;

[00032] Figure 8 is a rear elevationai view of the first preferred embodiment of the burner of Figure 1;

[00033] Figure 9 is a sectional side elevationai view of the first preferred embodiment of the burner of Figure 1 , taken along section line 9-9 of Figure 8;

[00034] Figure IV is a sectional top plan view of the first preferred embodiment of the burner of Figure 1, taken along section line 10-10 of Figure 8;

[00035] Figure 11 is a perspective view of the air-flow-controlling rear housing that is part of the first preferred embodiment burner of Figure I ;

[00036] Figure 12 is a side elevβtional view of the air-flow-conlrollϊng rear housing of Figure 11 ;

[00037] Figure 13 is a front elevationai view of the air-flow-controUing rear housing of Figure 1 1 ;

[00038] Figure 14 is a rear elevatiπnal view of the air-flow-controlling rear housing of Figure 11 ;

[00039] Figure 15 is a sectional side elevationai view of the air-flow-controlling rear housing of Figure 11, taken along section line 15-15 of Figure 13; [00040] Figure 16 is a sectional side elevational view of the air-flow-controlling rear housing of Figure 11 , taken along section line 16-16 of Figure 13;

[00041] Figure 17 is a sectional side elevational view of the air-flow-controlling rear housing of Figure 1 1, taken along section line 17-17 of Figure 13;

[00042] Figure 18 is a perspective view of the wider rear portion of the outer housing that is part of the first preferred embodiment burner of Figure 1 ;

[00043] Figure 19 is a side elevational view of the wider rear portion of the outer housing of Figure 18;

[00044] Figure 20 is a front elevational view of the wider rear portion of the outer housing of Figure 18;

[00045] Figure 21 is a rear elevational view of the wider rear portion of the outer housing of Figure ] 8;

[00046] Figure 22 is a sectional side elevational view of the wider rear portion of the outer housing of Figure 18, taken along section line 22-22 of Figure 20;

|00047] Figure 23 is a perspective view of the fuel nozzle that is part of the first preferred embodiment burner of Figure 1 ;

[00048] Figure 24 is a side elevational view of the fuel nozzle of Figure 23;

[00049] Figure 25 is a front elevational view of lhe fuel nozzle of Figure 23;

[00050] Figure 26 is a rear elevational view of the fuel nozzle of Figure 23; [00051 ] Figure 27 is a sectional side eJevational view of the fuel nozzle of Figure 23, taken along section line 27-27 of Figure 26;

[00052] Figure 28 is a perspective view of the narrower front portion of the outer housing that is part of the first preferred embodiment burner of Figure 1;

[00053] Figure 29 is an exploded perspective view of the narrower front portion of the outer housing of Figure 28;

[00054] Figure 30 is a left side elevational view of the narrower front portion of the outer housing of Figure 28;

[00055| Figure 31 is a right side elevational view of the narrower front portion of the outer housing of Figure 28;

[00056] Figure 32 is a top ptan view of the narrower front portion of the outer housing of Figure 28;

[00057 ] Figure 33 is a bottom plan view of the narrower front portion of the outer housing of Figure 28;

[00058] Figure 34 is a front elevational view of the narrower front portion of the outer housing of Figure 28;

[00059] Figure 35 is a rear elevational view of the narrower from portion of the outer housing of Figure 28;

[00060] Figure 36 is a sectional top plan view of the narrower front portion of the outer housing of Figure 28, taken along section line 36-36 of Figure 34;

[00061 ] Figure 37 is a sectional side elevational view of the narrower front portion of the outer housing of Figure 28, taken along section line 37-37 of Figure 34;

[00062 ] Figure 38 is a sectional side elevational view of the burner of Figure 1, with the combustion chamber in place, and in use;

|00063| Figqre 39 is a side elevational view of the second preferred embodiment of the burner according to the present invention;

[00064] Figure 40 is a sectional top plan view of the second preferred embodiment of the burner of Figure 39, taken along section line 40-40 of Figure 39;

|00065] Figure 41 is a side elevational view of the fuel nozzle that is part of the second preferred embodiment burner according to the present invention; and,

[00066] Figure 42 is a side elevational view similar to Figure 41 , but with the nozzle tip removed from the iuuzlc body.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[00067| Referring to Figures I through 42 of the drawings, it will be noted that Figures 1 through 38 are directed to a first preferred embodiment of the burner according to the present invention, and Figures 39 through 42 are directed to a second preferred embodiment of the fuel nozzle according to the present invention.

[00068] Reference will now be made to Figures 1 through 38, Reference will now be made to Figures 1 through 38, which show a first preferred embodiment of the burner according to the present invention, as indicated by general reference numeral 20. The preferred embodiment burner 20 comprises a main body 22 having a front end 24 and a back end 26. The main body 22 defines a longitudinal axis "L" extending between the front end 24 and the back end 26. It should be understood that although for some shapes of burners the determination of front end back and the back end might be somewhat arbitrary, the front end is generally defined as the flame is produced, and the back end is defined as the area where the air and the fuel have their inputs, and where the mixing of the air and the fuel begins.

[00069] It should be understood that for the sake of convenience, the term air is used to describe air received from a pressurized or compressed source ot air but that also oxygen from a pressurized or compressed source of oxygen could be used. If a source of air is used, the oxygen in the air is reacted with a fuel such as propane, natural gas, and so on. The nitrogen in the air is merely separated front the oxygen upon combustion. It is also contemplated that hydrogen could be used along with the oxygen.

[00070] In the preferred embodiment, as illustrated, but not necessarily, the main body 22 comprises an air-flow-contro!liπg rear housing 30 and an outer housing 40. The air-flow-controlling rear housing 30 is secured in removable and replaceable relation to the outer housing 40 by means of threaded fasteners 23. A substantially straight fuel nozzle SO resides within the air-flow-controlling rear housing 30 and the outer housing 40.

[00071 ] The outer housing 40 comprises a wider rear portion 42 and a narrower front portion 44. The wider rear portion 42 has a sloped outer surface 42a and throughpassage 43 with a sloped inner surface 43a and a fixed diameter portion 43b. The sloped inner surface 43a defines the outer wall of the wide air accumulator chamber 70. The fixed diameter portion 43b receives the substantially straight fuel nozzle 50 therein in close contacting relation.

[00072| The narrower front portion 44 comprises a cylindrical tube 44a, a rear flange 44b welded to the back end of the cylindrical tube 44a, and front plate 44c welded lo the front end of the cylindrical tube 44a. The narrower front portion 44 is secured to the wider rear portion 42 by means of threaded fasteners 41. The front plate 44c abuts against three support flanges 44d welded to the cylindrical tube 44, and is retained in place by threaded fasteners 44i The front plate 44c also has an annular flange 44e that abuts against an annular shoulder 44f located at the back end of a reduced diameter front end portion 44g of the narrower front portion 44. Further, the front plate 44c has a circular recess 44h for receiving the back end 45b of a combustion chamber tube 45 therein. The back end 45b of the combustion chamber tube 45 has a malc-thrcadcd portion 45c that threadibly engages a co-operating female-threaded portion 44h on the front plate 44c. The combustion chamber tube 45 forms a chamber wherein the flame produced by the burner 20 of the present invention is encapsulated. The length and internal diameter of the combustion chamber tube 45 can be selected to maximize the projection of the flame, as desired, and can also be selected to create specific reasonances related to the output (the flame) of the burner 20.

[00073 ] The aii-flow-controlling rear housing 30 comprises a main body 32 having a front end 33 and a back end 34. The longitudinal axis "L" extends between the front end 33 and the back end 34. Preferably, the main body 32 is made from metal, but may be made from any other suitable material.

[00074] The air-flow-controlling rear housing 30 further comprises a nozzle receiving passageway 36 in the main body 32. The nozzle receiving passageway 36 is generally centrally disposed in the main body 32 and oriented along longitudinal axis "L". The air-flow-controlling rear housing 30 also comprises an annular cone portion 37 extending forwardly from the main body 32. The nozzle receiving passageway 36 extends through the annular cone portion 37.

J00075I There is at least one air inlet in the main body 32, and in the preferred embodiment, as illustrated, there is a first air inlet 38 and a second air inlet 39 in the main body 32, specifically in the rear housing 32. The first air inlet 38 and the second air inlet 39 are spaced one hundred eighty degrees (180°) apart in order to effectively maximize the subsequent mixing of air flow The first air inlet 38 and the second air inlet 39 are each oriented generally along the longitudinal axis "L", as shown, but could alternatively be oriented at another angle. It is contemplated that there may also be additional air inlets in said main body 32 to accommodate the need for additional air input

[00076] It should also be noted that in an alternative embodiment, there could be additional inlets for introducing a secondary type of fuel, such as hydrogen and even including the un-burnt emissions from other types of burners, and the like.

[00077] The air-Ωow-controlling rear housing 30 comprises a substantially annular air gathering chamber 29 in the main body portion 32. The substantially annular air gathering chamber 29 is in fluid communication with the first air inlet 38 and the second air inlet 39. The substantially annular flow passage is substantially circular in shape.

[00078] There is also a substantially annular air-flow mixing chamber 100 within the main body portion 32. The substantially annular air-flow mixing chamber 100 is also substantially circular in shape. [00079] A substantially annular wall 1 10 generally divides the substantially annular air gathering chamber 29 and the substantially annular air-flow mixing chamber 100. The substantially annular wall 110 is substantially circular in shape.

[00080] The substantially annular air gathering chamber 29 generally surrounds the substantially annular air-flow mixing chamber 100. The height of the substantially annular air gathering chamber 29 and the height of the substantially annular air gathering chamber 100 are similar one to the other. Further, the substantially annular air gathering chamber 29 and the substantially annular air-flow mixing chamber 100 are substantially longitudinally aligned one with the other along the longitudinal axis "L".

[00081 ] The first air inlet 38 and the second air inlet 39 are disposed rearwardly of the substantially annular air gathering chamber 29 in order to cause properly directed forward flow of air into the air gathering chamber 29. Further, in this manner, the fittings that connect the air line. Lo the first air inlet 38 and the second air inlet 39 do not project laterally outwardly, which might be unsafe.

[00082] A first air flow opening 101 extends between the substantially annular air gathering chamber 29 and the substantially annular air-flow mixing chamber 100. The first air flow opening 101 has a first height that is a portion ofthe height of the substantially annular wall 1 10. There is also a second air flow opening 102 that extends between the substantially annular air gathering chamber 29 and the substantially annular air-flow mixing chamber 100. The second air flow opening 102 has a second height that is a portion of the height of the substantially annular wall 1 10. The height of the first air flow opening 101 is greater than the height of the second air flow opening 102.

[00083] The burner 20 further comprises a third air flow opening 103 extending between the substantially annular air gathering chamber 29 and the substantially annular air-flow mϊxing chamber 100. The third air flow opening 103 has a third height that is a portion of the height of the substantially annular wall 110. The height ofthe first air flow opening 101 is greater than the height of the third air flow opening 103, and the height of the second air flow opening 102 is greater than the height ofthe third air flow opening 103. [00094] The burner 20 also further comprises a fourth air flow opening 104 extending between the substantially annular air gathering chamber 29 and ihe substantially annular air-flow mixing chamber 100. The fourth air flow opening 104 has a fourth height that is a portion of the height of the substantially annular wall 110. The height of the first air flow opening 101 is greater than the height ofthe fourth air flow opening 104. The height of the second air flow opening 102 is greater than the height of the fourth air flow opening 104. The height of the third air flow opening 103 is greater than the height of the fourth air flow opening 104.

[00085] It has been found that having different heights of the first air flow opening 101, the second air flow opening 102, the third air flow opening 103 and the fourth air flow opening 104 produces an effective dynamic flow mixture of the air entering the substantially annular air-flow mixing chamber 100.

[00086] It is further contemplated that in another embodiment of the present invention, the first, second, third and fourth air flow openings could be oriented at an angle such that air flowing therethrough enters the substantially annular air-flow mixing chamber 100 obliquely, thereby helping to create annularly swirling flow patterns in the substantially annular air-flow mixing chamber 100.

[00087] The substantially straight fuel nozzle 50 comprises an elongate main body 55 having an inlet end 56 and an outlet end 57, and is substantially circular in cross-section. The main body 55 defines a longitudinal axis "L" extending between the inlet end 56 and the outlet end 57.

[00088] The fuel nozzle 50 has a substantially straight fuel passageway 58 centrally disposed in the elongate main body 55. The substantially straight fuel passageway 58 has a fuel receiving inlet 53 and a fuel emitting outlet 54 for delivering fuel to a mixing chamber 80 of the burner 20, by passing a flow of fuel from the fuel receiving inlet 53 to the fuel emitting outlet

54. Tn the first preferred embodiment, as illustrated, the fuel emitting outlet 54 actually comprises a first fuel emitting outlet

54a, a second fuel emitting outlet 54b, a third fuel emitting outlet 54c, a fourth fuel emitting outlet 54d, a fifth fuel emitting outlet 54e, and a sixth fuel emitting outlet 54f. The first fuel emitting outlet 54a, the second fuel emitting outlet 54b, the third fuel emitting outlet 54c, the fourth fuel emitting outlet 54d, the fifth fuel emitting outlet 54c, and the sixth fuel emitting outlet 54f are each oriented at an angle of about ten degrees with respect to the longitudinal axis "L", which has been found to disperse the fuel fully for ready evaporation by the air. Any other suitable angle may alternatively be used.

[00089] Preferably, the elongate main body 55 comprises a narrow back portion 55ahavinga circular cross-section, a wider front portion 55b having a circular cross-section, and a sloped portion 55c interconnecting the narrow back portion 55a and the wider front portion 55b, The fuel receiving inlet 53 is disposed at the inlet end 56 and the fuel emitting outlet 54 is disposed at the outlet end 57. The sloped portion 55c of the fuel nozzle 50 engages in scaling contact with a co-operating receiving surface 21 on the main body of the burner 20. There is also a stepped nozzle fitting portion 59 on the fuel passageway

58 at the inlet end 56 of the main body 55.

[00090] The fuel nozzle 50 also comprises an externa! rear portion 51 that projects rearwardly from the back end 26 of the main body 22 of the burner 20. Preferably, the external rear portion 51 of the fuel nozzle 50 is threaded to accept a co-operating nut 52 thereon, to thereby retain the fuel nozzle 50 Ln place in the main body 32.

[00091] In orderto permit air flow from a source of compressed air (not specifically shown) to the mixing chamber 80 of the burner 20, there is a first air flaw channel 90a, a second air flow channel 90b, a third air flow channel 90c, a fourth air flow channel 90d, and a fifth air flow channel 9Oe. It has been found that it is preferable to have this number of air flow channels for the purpose of even air flow and distribution there are two or more air flow channels 90. Any suitable number of air flow channels 90 could be used depending on the specific application of the burner 20, the size of the burner 20 and the fuel nozzle 50, and so on. Various fuel nozzles according to the present invention have been tried, including from two air flow channels 90 on up. It has been found that each specific number of air flow channels might have its own advantages and disadvantages.

[00092] Each of the first, second, third, fourth and fifth air flow channels 90a, 90b, 90c, 90d, 90e has an inlet 91 , and an outlet 92 disposed adjacent the fuel emitting outlet 54 for delivering air to the mixing chamber 80 of the burner 20. As can be readily seen in the figures, the portion 93 of each of the first air flow channel 90a, the second air flow channel 90b, the third air flow channel 90c, the fourth air flow channel 9Od, and the fifth air flow channel 9Oe adjacent the outlet that air flow channel is oriented obliquely to the longitudinal axis "L". More specifically, substantially all of the first air flow channel 90a, the second air flow channel 90b, the third air flow channel 90c, the fourth air flow channel 9Od, and the fifth air flow channel 90e is oriented obliquely to the longitudinal axis "L". Even more specifically, each of the first air flow channel 90a, the second air flow channel 90b, the third air flow channel 90c, the fourth air flow channel 90d, and the fifth air flow channel 90c is helically shaped. Each of the plurality of helically shaped air flow channels 90 is substantially parallel to adjacent helically shaped air flow channels 90. The helically shaped air flow channels 90 are preferably disposed on the exterior of the fuel nozzle

50.

[00093] The inlet 91 of the first air flow channel 90a has a cross-sectional area that is greater than the cross-sectional area of the outlet 92 of the same first air flow channel 90a; the inlet 91 of the second air flow channel 90b has a cross-sectional area that is greater than the cross-sectional area of the outlet 92 of the same second air flow channel 90b; the inlet 91 of the third air flow channel 90c has a cross-sectional area that is greater than the cross-sectional area of the outlet 92 of the same third air flow channel 90c; the inlet 91 of the fourth air flow channel 90d has a cross-sectional area that is greater than the cross-sectional area of the outlet 92 of the same fourth air flow channel 90d; the inlet 91 of the fifth air flow channel 90e has a cross-sectional area that is greater than the cross-sectional area of the outlet 92 of the same fift h air flow channel 90c. Preferably, the cross-sectional area of each of the inlets 91 are the same one as the other and cross-sectional area of each of the outlets 92 are the same one as the other.

[00094] Further, the ratio of the cross-sectional area of the inlet 91 of the first air flow channel 90a to the cross-sectional area of the outlet 92 of the same first air flow channel 90a is about 1.6 to 1 ; the ratio of the cross-sectional area of the inlet 91 of the second air flow channel 90b to the cross-sectional area of the outlet 92 of the same second air flow channel 90b is also about 1.6 to 1; the ratio of the cross-sectional area of the inlet 91 of the third air flow channel 90c to the cross-sectional area of the outlet 92 of the same third air flow channel 90c is also about 1.6 to 1 ; the ratio of the cross-sectional area of the inlet 91 of the fourth flow channel 9Od to the cross-sectional area of the outlet 92 of the same fourth air flow channel 90d is also about 1.6 to 1 ; and the ratio of the cross-sectional area of the inlet 91 of the fifth air flow channel 9Oe to the cross-sectional area of the outlet 92 of the same fifth air flow channel 90b is also about 1.6 to 1.

[000951 It has been found that the ratio of about 1.6 to 1 can be more accurately expressed as the golden ratio, also known as the golden number, which is often denoted by the Greek letter PHI (φ) and is determined by the mathematical expression ( 1 + which is approximately equal to 1.618033987.

[00096] Further, it is preferable that the cross-sectional area of each ofthe five air flow channels 90 decreases from the inlet 91 to the outlet 92. More specifically, it is also preferable that lhe width of each of the five air flow channels 90 decreases from the inlet 91 to the outlet 92, for ease of manufacturing, while the depth remains constant. It is quite perm issible for the depth of the five airflow channels 90 to also decrease from the inlet 91 to lhe outlet 92, either additionally to the decrease in width of the channels 90, or instead of the decrease in width of the channels 90.

[00097J As can be best seen in Figure 1, the wider front portion 55b of the fuel nozzle 50 contacts the constant cross-section front portion 24 of the burner 20 in sealed relation. Accordingly, air must pass through the helically shaped air flow channels 90 in order to reach the mixing chamber 80.

[00098] As can be seen in the Figures, the six fuel emitting outlets 54a, 54b, 54c, 54d, 54c, and 54f arc disposed slightly forwardly of the outlets of the five air flow channels 90a, 90b, 90c, 9Od, and 90e in order to permit air flowing from the five air flow channels 90a, 90b, 90c, 9Od, and 90e to carry forward and, in essence, "pick-up" and mix with the fuel from the six fuel emitting outlets 54a, 54b, 54c, 54d, 54e, and 54f of the fuel nozzle 50-

[00099] The burner 20 also has amixing chamber 80 that is fluid communication with the fuel emitt ing outlets 54a,

54b, 54c, 54d, 54e, and 54f and the outlets 92 of the five air flow channels 90a, 90b, 90c, 9Od, and 9Oe. The mixing chamber 80 is disposed forwardly of the fuel emitting oullets 54a, 54b, 54c, 54d, 54e, and 54f of the fuel nozzle 50 and the outlets 92 of the five air flow channels 90a, 90b, 90c, 9Od, and 9Oe, and is aligned along the longitudinal axis "L" with the fuel passageway

58.

[000100] The burner 20 further comprises a wide air accumulator chamber 70 interposed in fluid communication between both the first air inlet 38 and the second air inlet 39, and the five helical Iy shaped air flow channels 90a, 90b, 90c, 9Od, and 9Oe. Preferably, the wide air accumulator chamber 70 is annular in shape and tapers (narrows) from back to front. The wide air accumulator chamber 70 has a narrow air-receiving ingress 72 is in fluid communication with the first air inlet 38 and the second air inlet 39, through the air-flow-controlling rear housing30. Accordingly, the wide airaccutnulator chamber 70 receives air from the first air inlet 38 and the second air inlet 39. The wide air accumulator chamber 70 also has a narrow air egress 74. Accordingly, air from the first air inlet 38 and me second air inlet 39 is passed to the five helically shaped air flow channels 90a, 90b, 90c, 9Od, and 9Oe in the fuel nozzle 50.

[000101 ] It has been found that the wide air accumulator chamber 70 together with the air-receiving ingress 72 and the narrow air egress 74 tend to accelerate air traveling from the substantially annular air-flow mixing chamber 100 to the helically shaped air flow channels 90. The cross-sectional area of the air egress 74 is narrower than the cross-sectional area of the wide air accumulator chamber 70, as measured transversely with respect to the longitudinal axis "L".

[ 000102] In use, with reference to Figure 38, air enters the air-flow-controlling rear housing 30 through the at least one air inlet 38 and a second air inlet 39, and first gathers in the substantially annular air gathering chamber 29. The air passes from the substantially annular air gathering chamber 29 to the substantially annular air-flow mixing chamber 100 via the first air flow opening 101, the second air flow opening 102, the third air flow opening 103 and the fourth air flow opening 104, The offset depths of the first air flow opening 101, the second air flow opening 102, the third air flow opening 103 and the fourth air flow opening 104 cause the air to enter the substantially annular air-flow mixing chamber 100 at four distinct and separate "levels" (with respect to the longitudinal axis "L"), thus causing non-laminar flow of the air, In this manner, the air is as turbulent as possible in order to facilitate full mixing of the air downstream with fuel from the fuel nozzle tip 60. The air then passes through the wide air accumulator chamber 70, and exits through the narrow air egress 74, which accelerates the flow of the air.

[000103] Next, air from the wide air accumulator chamber 70 must enter and pass through the first air flow channel 90a, the second air flow channel 90b, the third air flow channel 90c, the fourth air flow channel 9Od, and the fifth air flow channel 9Oe immediately before being emitted to the mixing chamber 80 of the burner 20. The fast flow of air then passes by the outlet end 57 of the Elongate main body 55 of the substantially straight fuel nozzle 50 and past the fuel nozzle tip 60, to then mix with the fuel emanating from the fuel nozzle tip 60. Due to the decrease in cross-sectional area of the five air flow channels 90a, 90b, 90c, 90d, and 90e, from the inlets 91 to the outlets 92, the air exits the outlets 92 at a significantly higher rate of speed than the speed it enters the inlets 91.

[000104] Further, due to the fact that the first air Dow channel 90a, the second air flow channel 90b, the third air flow channel 90c, the fourth air flow channel 9Od, and the fifth air flow channel 9Oe are all helically shaped, the air exiting the outlets 92 of each of these five air flow channels 90 travels in a fast-swirling helical patt ern along the mixing chamber 80, as indicated by arrow "B", towards the combustion chamber 82, and then even in the combustion chamber 82. The swirling of the air in the combustion chamber 82 provides for a substantially lengthened path of travel for the air within the combustion chamber 82, as compared to the actual length of the combustion chamber 82. In this manner, there is a significantly longer dwell time for the air, and also the fuel that the air has "picked up". The fuel is widely dispersed, as indicated by arrows "A", into the swirling air. Due to the swirling of the air, there is a significantly lengthy time for combustion to occur, and therefore heat generation to occur, and therefore a significant amount of time for heat transfer to occur from the combustion chamber 82, through the combustion chamber tube 85, and to the ambient surroundings, where the heat is delivered to a desired destination. In tests, it has been found that flame temperature of the burner 20 of the present invention can readily be in excess of 2000 degrees, and produce a stack temperature of about 400 degrees Fahrenheit, which is a drop of 1600 degrees Fahrenheit that has gone into elevating the temperature of the object to be heated. Typically, in prior art burners, there is a flame temperature of about 1600 degrees Fahrenheit and a stack temperature of about 800 degrees Fahrenheit which transfer to only 800 degrees temperature difference that is used to heat an object.

[000105 ] Reference will now be made to Figures 39 through 42, which show a second preferred embodiment of the burner according to the present invention, as indicated by the general reference numeral 220. The second preferred embodiment burner 220 is similar to the first preferred embodiment of the burner 20 except that the outer housing 240 is much larger in terms of its wall thickness. Also, the substantially annular wall 210 in the rear housing 230 is substantially thicker. Further, the fuel nozzle 250 comprises a fuel nozzle tip 260 mounted in removable and replaceable relation in the front end 257 of the elongate main body 255 of the fiiel nozzle 250. Preferably, the threaded back portion 268 of the fuel nozzle tip 260 engages a co-operating threaded front end portion 259 in the fuel passageway 258. The fuel nozzle tip 260 is mounted in removable and replaceable relation as described, to permit ready replacement of the fuel nozzle tip 260 in the event of damage, and also to permit selection of an appropriate fuel nozzle tip 260 for an end application, such as placement in a boiler, line heater, or furnace. [000106] As can be understood from the above description and from the accompanying drawings, the present invention provides a fuel nozzle that causes a burner to bum fuel very efficiently, that produces minimal unwanted emissions, that can be used with various types of gaseous and liquid fuel, and that is cost effective, all of which features are unknown in the prior an.

[000107] Other variations of the above principles will be apparent to those who are knowledgeable in the field of the invention, and such variations are considered to be within the scope of the present invention. Further, other modifications and alterations may be used in the design and manufacture of the fuel nozzle of the present invention without departing from the spirit and scope of die accompanying claims.

Claims

WE CLAIM:

1. A burner comprising:

a main body having a front end and a back end and defining a longitudinal axis extending between said front end and said back end;

at least one air inlet;

a mixing chamber;

a fiiel passageway having a fuel receiving inlet, and a fuel emitting outlet for delivering fuel to said mixing chamber, and,

a first air flow channel having an inlet in fluid communication with said at least one air inlet, and an outlet disposed adjacent said fuel emitting outlet, for delivering air to said mixing chamber;

wherein the portion of said first air flow channel adjacent said outlet is oriented obliquely to said longitudinal axis.

2. The burner of claim 1, further comprising an air accumulator chamber interposed in fluid communication between said at least one air inlet and said first air flow channel.

3. The burner of claim 2, wherein the cross-sectional area of said air egress is narrower than the cross-sectional area of said air accumulator chamber.

4. The burner of claim i, wherein substantially all of said first air flow channel is oriented obliquely to said longitudinal axis.

5. The burner of claim 4, wherein said first air flow channel is helically shaped.

6. The burner of claim 1, wherein said inlet of said first air flow channel has a cross-sectional area that is larger than the cross-sectional area of said outlet of said first air flow channel.

7. The burner of claim 6, wherein the ratio of the cross-sectional area of said inlet of said first air flow channel to the cross-sectional area of said outlet of said first air flow channel is about 1.6 to 1.

8. The burner of claim 6, wherein the cross-sectional area of said first air flow channel decreases from said inlet to said outlet,

9. The burner of claim 8, wherein the width of said first air flow channel decreases from said inlet to said outlet.

10. The burner of claim 9, wherein the depth of said first air flow channel decreases from said inlet to said outlet.

1 1. The burner of claim 1, further comprising a fuel nozzle disposed within said main body, said fuel nozzle having said fuel passageway, said fuel receiving inlet and said fuel emitting outlet.

12. The burner of claim 1 1, wherein said fuel nozzle has a front end and a back end and is substantially straight.

13. The burner of claim 12, wherein said fuel passageway is substantially straight.

14. The burner of claim 11 , wherein said first air flow channel is disposed on the exterior of said fuel nozzle.

15. The burner of claim 1 1, further comprising a second air flow channel.

16. The burner of claim 1 5, wherein said first air flow channel and said second air flow channel are substantially parallel one to another.

17. The burner of claim 16, wherein said first air flow channel and said second air flow channel are helically shaped.

18. The burner of claim 17, wherein said inlet of said second air flow channel has a cross-sectional area that is larger than the cross-sectional area of said outlet of said second air flow channel.

19. The burner of claim 18, wherein the ratio of the cross-sectional area of said inlet of said first air flow channel to the cross-sectional area of said outlet of said first air flow channel is about 1.6 to 1.

20. The burner of claim 18, wherein the cross-sectional area ofsaidfrrst air flow channel decreases from said inlet to said outlet.

21. The burner of claim 20, wherein the width of said first air flow channel decreases from said inlet to said outlet.

22. The burner of claim 21 , wherein the depth of said first air flow channel decreases from said inlet to said outlet.

23. The burner of claim 15, further comprising a third air flow channel, a fourth air flow channel and a fifth air flow channel.

24. The burner of claim 23, wherein said first air flow channel, said second air flow channel, said third air flow channel, said fourth air flow channel and said fift h air flow channel are substantially parallel one to another.

25. The burner of claim 24, wherein said third air flow channel, said fourth air flow channel and said fifth air flow channel are helically shaped.

26. The burner of claim 12, wherein said fuel nozzle comprises an elongate main body having an inlet end and an outlet end, and wherein said fuel receiving inlet is disposed at said inlet end and said fuel emitting outlet is disposed at said outlet end.

27. The burner of claim 26, wherein said elongate main body comprises a narrow back portion and a wider front portion.

28. The burner of claim 27, wherein said elongate main body of said fiiel nozzle further comprisesasloped portion interconnecting said narrow back portion and said wider front portion.

29. The burner of claim 28, wherein said sloped portion of said fuel nozzle engages in sealing contact with a co-operating receiving surface on said main body.

30. The burner of claim 29, wherein said fuel nozzle comprises a rear portion that is threaded to engage a co-operating nut to thereby retain said fuel nozzle Ln place in said main body.

31. The burner of claim 1, further comprising a second air inlet in said main body, and wherein said at least one helically shaped air flow channel is in fluid communication with said second air inlet

32. The burner of claim 1, further comprising a fuel nozzle tip mounted in removable and replaceable: relation in the front end of said elongate main body of said fuel nozzle.

33. The burner of claim 1, wherein said mixing chamber is aligned along said longitudinal axis with said fuel passageway.

34. The burner of claim 1 , further comprising a combustion chamber extension mounted on said main body so as to extend forwardly from the front end of said main body.

3 5. The burner of claim 34, wherein said combustion chamber extension is mounted in removable and replaceable relation on said outer housing.

36. The burner of claim 1, further comprising a substantially annular air gathering chamber in said main body and in fluid communication with said at least one air inlet, a substantially annular air-flow mixing chamber within said main body, a substantially annular wall generally dividing said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, a first air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a first height that is a portion of the height or said substantially annular wall, and a second air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a second height mat is a portion of the height of said substantially annular wall, and wherein the height of said first air flow opening is greater than the height of said second air flaw opening.

37. The burner of claim 36, further comprising a third air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a third height that is a portion of the height of said substantially annular wall, and wherein the height of said first air flow opening is greater than the height of said third air flow opening, and the height of said second air flow opening is greater than the height of said third air flow opening.

38. The burner of claim 37, further comprising a fourth air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a fourth height that is a portion of the height of said substantially annular wall, and wherein the height of said first air flow opening is greater than the height of said fourth air flow opening, the height of said second air flow opening is greater than the height of said fourth air flow Opening, and height of said third air flow opening is greater than the height of said fourth air flow opening.

39. The burner of claim 38, wherein said substantially annular flow passage is substantially circular in shape.

40. The burner of claim 39, wherein said substantially annular wall is substantially circular in shape.

41 The burner of claim 40, wherein said wherein the height of said substantially annular flow passage and the height of said air gathering chamber are similar one to the other.

42. The burner of claim 40, wherein said substantially annular air gathering chamber generally surrounds said substantially annular air-flow mixing chamber.

43. The burner of claim 42, wherein said substantially annular air gathering charmber and said substantially annular air-flow mixing chamber are substantially longitudinally aligned one with the other along said longitudinal axis.

44. The burner of claim 40, wherein said at least one air inlet is disposed rearwardly of said substantially annular air gathering chamber.

45. The burner of claim 1, wherein said main body comprises an air-flow-controlling rear homing and an outer housing.

46. A burner comprising:

an outer housing having a nozzle-receiving throughpassage;

a mixing chamber, and,

a fuel nozzle disposed in said nozzle-receiving throughpassage of said outer housing, and having a fuel passageway having a fuel receiving inlet, and a fuel emitting outlet for delivering fuel to said mixing chamber;

wherein said outer housing and said fuel nozzle together define a first air flow channel for delivering air to said mixing chamber.

47. The burner of claim 41 , wherein said main body comprises an air-flow-controlling rear housing and an outer housing.

48. The burner of claim 47, wherein said rear bousing and said outer housing are operatively secured one to the other such that said throughpassage of said rear housing and said throughpassage of said outer housing are in fluid communication one with the other.

49. The burner of claim 48, wherein said rear housing and said outer homing are operatively secured one to the other such that said outer housing is disposed generally forwardly of said rear housing.

50. The burner of claim 49, wherein said mixing chamber is disposed at said front end of said outer housing.

51. The burner of claim 46, further comprising an air accumulator chamber interposed in fluid communication between said at least one air inlet and said first air flow channel.

52. The burner of claim 46, wherein substantially all of said first air flow channel is oriented obliquely to said longitudinal axis.

53. The burner of claim 52, wherein said first air flow channel is helically shaped.

54. The burner of claim 46, wherein said inlet of said first air flow channel has a cross-sectional area that is larger than the cross-sectional area of said outlet of said first air flow channel.

55. The burner of claim 54, wherein the ratio of the cross-sectional area of said inlet of said first air flow channel Io the cross-sectional area of said outlet of said first air flow channel is about 1.6 to 1.

56. The burner ofclaim 54, wherein the cross-sectional area of said first air flow channel decreases from said inlet to said outlet.

57. The burner of claim 56, wherein the width of said first air flow channel decreases from said inlet to said outlet.

58. The burner of claim 57, wherein the depth of said first air flow channel decreases from said inlet to said outlet

59. The burner of claim 46, wherein said fuel nozzle has a front end and a back end and is substantially straight

60. The burner of claim 59, wherein said fuel passageway is substantially straight.

61. The burner of claim 46, wherein said first air flow channel is disposed on the exterior of said fuel nozzle.

62. The burner of claim 46, further comprising a second air flow channel.

63. The burner of claim 62, wherein said first air flow channel and said second air flow channel are substantially parallel one to another.

64. The burner of claim 63, wherein said first air flow channel and said second air flow channel are helically shaped.

65. The burner of claim 64, further comprising a third air flow channel, a fourth air flow channel and a fifth air flow channel.

66- The burner of claim 65, wherein said first air flow channel, said second air flow channel, said third air flow channel, said fourth air flow channel, and said fifth air flow channel are substantially parallel one to another.

67. The burner of claim 66, wherein said third air flow channel, said fourth air flow channel and said fifth air flow channel are helically shaped.

68. The burner of claim 46, wherein said fuel nozzle comprises an elongate main body having an inlet end and an outlet end, and wherein said fuel receiving inlet is disposed at said inlet end and said fuel emitting outlet is disposed at said outlet end.

69. This burner of claim 68, wherein said elongate main body comprises a narrow back portion and a wider front portion.

70 The burner of claim 69, wherein said elongate main body of said fuel nozzle further comprises a sloped portion interconnecting said narrow back portion and said wider front portion.

71. The burner of claim 70, wherein said sloped portion of said fuel nozzle engages in sealing contact with a co-operating receiving surface on said main body.

72. The burner of claim 71, wherein said fuel nozzle comprises a rear portion that is threaded to engage a co-operating nut to thereby retain said fuel nozzle on place in said main body

73 The burner of claim 46, further comprising a second air inlet in said main body, and wherein said at least one helically shaped air flow channel is in fluid communication with said second air inlet.

74. The burner of claim 46, further comprising a fuel nozzle tip mounted in removable and replaceable relation in the front end of said elongate main body of said fuel nozzle.

75. The burner of claim 46, wherein said mixing chamber is aligned along said longitudinal axis with said fuel passageway.

76. The burner of claim 46, further comprising a combustion chamber extension mounted on said main body so as to extend forwardly from the front end of said main body,

77 The burner of claim 76, wherein said combustion chamber extension is mounted in removable and replaceable relation on said outer housing.

78. The burner of claim 46, further comprising a substantially annular air gathering chamber in said main body and in fluid communication with said at least one air inlet, a substantially annular air-flow mixing chamber within said main body, a substantially annular wall generally dividing said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, a first air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a first height that is a portion of the height of said substantially annular wall, and a second air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a second height that is a portion of (he height of said substantially annular wall, and wherein the height of said first air flow opening is greater than the height of said second air flow opening

79. The burner of claim 78, further comprising a third air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a third height that is a portion of the height of said substantially annular wall, and wherein the height of said first air flow opening is greater than the height of said third air flow opening, and the height of said second air flow opening is greater than the height of said third air flow opening

80. The burner of claim 79, further comprising a fourth air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, andhaving a fourth height that is a portion of the height of said substantially annular wall, and wherein the height of said first air flow opening is greater than the height of said fourth air flow opening, the height of said second air flow opening is greater than the height of said fourth air flow opening, and height of said third air flow opening is greater than the height of said fourth air flow opening.

81. The burner of claim 80, wherein said substantially annular flow passage is substantially circular in shape.

82 The burner of claim 81 , wherein said substantially annular wall is substantially circular in shape.

83. The burner of claim 80, wherein said wherein the height of said substantially annular flow passage and the height of said air gathering chamber are similar one to the other.

84. The burner of claim 80, wherein said substantially annular air gathering chamber generally surrounds said substantially annular air-flow mixing chamber.

85. The burner of claim 84, wherein said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber arc substantially longitudinally aligned one with the other along said longitudinal axis.

86. The burner of claim 80, wherein said at least one air inlet is disposed rearwardly of said substantially annular air gathering chamber.

87. A burner comprising:

a main body;

at least one air inlet;

a mixing chamber;

a fuel passageway having a fuel receiving inlet, and a fuel emitting outlet for delivering fuel to said mixing chamber;

a first air flow channel having an inlet in fluid communication with said at least one air inlet, and an outlet disposed adjacent said fuel emitting outlet, for delivering air to said mixing chamber, and,

an air accumulator chamber;

wherein the cross-sectional area of said air accumulator chamber is greater than the cross-sectional area of said first air flow channel adjacent at said inlet.

88. The burner of claim 87, wherein said wide air accumulator chamber is annular in shape.

89. The burner of claim 88, wherein said wide air accumulator chamber tapers from back to front.

90. The burner of claim 88, further comprising a widened annular portion in fluid communication with said air egress and disposed immediately forwardly of said air egress.

91. The burner of claim 87, wherein substantially all of said first air flow channel is oriented obliquely to said longitudinal axis.

92. The burner of claim 91, wherein said first air flow channel is helically shaped.

93. The burner of claim 87, wherein said inlet of said first air flow channel has a cross-sectional area that is greater than the cross-sectional area of said outlet of said first air flow channel.

94. The burner of claim 93, wherein the ratio of the cross-sectional area of said inlet of said first air flow channel to the cross-sectional area of said outlet of said first air flow channel is about 1.6 to 1.

95. The burner of claim 93, wherein the cross-sectional area of said first air flow channel decreases from said inlet to said outlet.

96. The burner of claim 95, wherein the width of said first air flow channel decreases from said inlet to said outlet.

97 The burner of claim 96, wherein the depth of said first air flow channel decreases from said inlet to said outlet.

98. The burner of claim 87, wherein said fuel nozzle has a fuel passageway for passing a flow of fuel from said fiiel receiving inlet to said fuel emitting outlet,

99. The burner of claim 87, wherein said fuel nozzle has a front end and a back end and is substantially straight.

100. The burner of claim 99, wherein said fuel passageway is substantially straight.

101. The burner of claim 99, wherein said first air flow channel is disposed on the exterior of said fuel nozzle.

102. The burner of claim 97, further comprising a second air flow channel.

103. The burner of claim 102, wherein said fust air flow channel and said second air flow channel are substantially parallel one to another.

104. The burner of claim 103, wherein said first air flow channel and said second air flow channel are helically shaped.

105. The burner of claim 104, further comprising a third air flow channel, a fourth air flow channel and a fifth air flow channel.

106. The burner of claim 105, wherein said first air flow channel, said second air flow channel, said third air flow channel, said fourth air flow channel and said fifth air flow channel are substantially parallel one to another.

107. The burner of claim 106, wherein said third air flow channel, said fourth air flow channel and said fifth air flow channel are helically shaped.

108. The burner of claim 87, wherein said fuel nozzle comprises an elongate main body having an inlet end and an outlet end, and wherein said fuel receiving inlet is disposed at said inlet end and said fuel emitting outlet is disposed at said outlet end.

109. The burner of claim 10S, wherein said elongate main body comprises a narrow back portion and a wider front portion.

1 10. The burner of claim 109, wherein said elongate main body of said fuel nozzle further comprises a sloped portion interconnecting said narrow back portion and said wider front portion.

111. The burner of claim Il 0, wherein said sloped portion of said fuel nozzle engages in sealing contact with a co-operating receiving surface on said main body.

1 12. The burner of claim 1 11, wherein said fuel nozzle comprises a rear portion that is threaded to engage a co-operating threaded female socket on said rear housing.

113. The burner of claim 112, further comprising a metallic washer disposed between the back end of said fuel nozzle and said rear housing.

1 14. The burner of claim 87, further comprising a second air inlet in said main body, and wherein said at least one helically shaped air flow channel is in fluid communication with said second air inlet.

1 15. The burner of claim 87, further comprising a fuel nozzle tip mounted be removable and replaceable relation in the front end of said elongate main body of said fuel nozzle.

116. The burner of claim 87, wherein said mixing chamber is aligned along said longitudinal axis with said fuel passageway.

117. The burner of claim 87, further comprising a combustion chamber extension mounted on said outer housing so as to extend forwardly from said outer housing.

118. The burner of claim 117, wherein said combustion chamber extension is mounted in removable and replaceable relation on said outer housing.

119. Th* burner of claim 87, further comprising a substantially annular air gathering chamber in said main body and in fluid communication with said at least one air inlet, a substantially annular air-flow mixing chamber within said main body, a substantially annular wall generally dividing said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, a first air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a first height that is a portion of the height of said substantially annular wall, and a second air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a second height that is a portion of the height of said substantially annular wall, and wherein the height of said first air flow opening is greater than the height of said second air flow opening.

120. The burner of claim 1 19, further comprising a third air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-tlow mixing chamber, and having a third height that is a portion of the height of said substantially annular wall, and wherein the height of said first air flow opening is greater than the height of said third air flow opening, and the height of said second air flow opening is greater than the height of said third air flow opening.

121. The burner of claim 120, further comprising a fourth air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a fourth height that is a portion of the height of said substantially annular wall, and wherein the height of said first air flow opening is greater than the height of said fourth air flow opening, the height of said second air flow opening is greater than the height of said fourth air flow opening, and height of said third air flow opening is greater than the height of said fourth air flow opening.

122. The burner of claim 121, wherein said substantially annular flow passage is substantially circular in shape.

123. The burner of claim 122, wherein said substantially annular wall is substantially circular in shape.

124. The burner of claim 121, wherein said wherein the height of said substantially annular flow passage and the height of said air gathering chamber are similar one to the other.

125. The burner of claim 121, wherein said substantial Iy annular air gathering chamber generally surrounds said substantially annular air-flow mixing chamber,

126. The burner of claim 12S, wherein said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber are substantially longitudinally aligned one with the other along said longitudinal axis

127. The burner of claim 12l, wherein said at least one air inlet is disposed rearwardly of said substantially annular air gathering chamber.

128. The burner of claim 127, wherein said at least one air inlet is oriented generally along said longitudinal axis.

129. The burner of claim 121, wherein said main body comprises an air-fiow-controlling rear housing and an outer housing.

130. A burner comprising:

a main body;

at least one air inlet;

a mixing chamber;

a fuel passageway having a fuel receiving inlet, and a fuel emitting outlet for delivering fuel to said mixing chamber; and,

a first air flow channel having an inlet Ln fluid communication with said at least one air inlet, and an outlet disposed adjacent said fuel emitting outlet, for delivering air to said mixing chamber, wherein said inlet of said first air flow channel has a cross-sectional area that is larger than the cross-sectional area of said outlet of said first air flow channel.

131. The burner of claim 130, further comprising an air accumulator chamber interposed in fluid communication between said at least one air inlet and said first air flow channel.

132. The burner of claim 131, wherein the cross-sectional area of said air egress is narrower than the cross-sectional area of said air accumulator chamber.

133. The burner of claim 130, wherein substantially all of said first air flow channel is oriented obliquely to said longitudinal axis.

134. The burner of claim 133, wherein said first air flow channel is helically shaped.

135. The burner of claim 134, wherein the ratio of the cross-sectional area of said inlet of said first air flow channel to the cross-sectional area of said outlet of said first air flow channel is about 1.6 to 1.

136. The burner of claim 134, wherein the cross-sectional area of said first air flow channel decreases from said inlet to said outlet.

137. The burner of claim 136, wherein the width of said first air flow channel decreases from said inlet to said outlet.

138. The burner of claim 137, wherein the depth of said first air flow channel decreases from said inlet to said outlet.

139. The burner of claim 130, further comprising a fuel nozzle disposed within said main body, said fuel nozzle having said fuel passageway, said fuel receiving inlet and said fuel emitting outlet.

140. The burner of claim 139, wherein said fuel nozzle has a front end and a back end and is substantially straight

141 The burner of claim 140, wherein said fuel passageway is substantially straight

142. The burner of claim 139, wherein said first air flow channel is disposed on the exterior of said fuel nozzle.

143. The burner of claim 139, further comprising a second air flow channel.

144. The burner of claim 143, wherein said first air flow channel and said second air flow channel are substantially parallel one to another.

145. The burner of claim 144, wherein said first air flow channel and said second air flow channel are helically shaped.

146. The burner of claim 145, wherein said inlet of said second air flow channel has a cross-sectional area that is larger than the cross-sectional area of said outlet of said second air flow channel.

147. The burner of claim 146, wherein the ratio of the cross-sectional area of said inlet of said first air flow channel to the cross-sectional area of said outlet of said first air flow channel is about 1.6 to 1.

148. The burner of claim 147, wherein the eross-sertiona! area of said first air flow channel decreases from said inlet to said outlet.

149. The burner of claim 148, wherein the width of said first air flow channel decreases from said inlet to said outlet.

1 50. The burner of claim 149, wherein the depth of said first air flow channel decreases from said inlet to said outlet.

151. The burner of claim 143, further comprising a third air flow channel, a fourth air flow channel and a fifth air flow channel.

1 52. The burner of claim 151, wherein said first air flow channel, said second air flow channel, said third air flow channel, said fourth air flow channel and said fifth air flow channel are substantially parallel one to another.

I S3. The burner of claim 1 52, wherein said third air flow channel, said fourth air flow channel and said fifth air flow channel are helically shaped.

1 54. The burner of claim 140, wherein said fuel nozzle comprises an elongate main body having an inlet end and an outlet end, and wherein said fuel receiving inlet is disposed at said inlet end and said fuel emitting outlet is disposed at said outlet end.

1 55. The burner of claim 1 54, wherein said elongate main body comprises a narrow back portion and a wider front portion.

156. The burner of claim 155, wherein said elongate main body of said fuel nozzle further comprises a sloped portion interconnecting said narrow back portion and said wider front portion.

157. The burner of claim 156, wherein said sloped portion of said fuel nozzle engages in sealing contact with a co-operating receiving surface on said main body.

158. The burner of claim 157, wherein said fuel nozzle comprises a rear portion that is threaded to engage a co-operating nut to thereby retain said fuel nozzle on place in said main body.

1 59. The bυmer of claim 1, further comprising a second air inlet in said main body, and wherein said at least one helically shaped air flow channel is in fluid communication with said second air inlet.

160. The burner of claim I , further comprising a fuel nozzle tip mounted in removable and replaceable relation in the front end of said elongate main body of said fuel nozzle.

161. The burner of claim 1 , wherein said mixing chamber is aligned along said longitudinal axis with said fuel passageway.

162. The burner of claim 1 , further comprising a combustion chamber extension mounted on said main body sι> as to extend forwardly from the front end of said main body.

163. The burner of claim 162, wherein said combustion chamber extension is mounted in removable and replaceable relation on said outer housing.

164. The burner of claim 1 , further comprising a substantially annular air gathering chamber in said main body and in fluid communication with said at least one air inlet, a substantially annular air-flow mixing chamber within said main body, a substantially annular wall generally dividing said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, a first air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a first height that is a portion of the height of said substantially annular wall, and a second air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flόw mixing chamber, and having a second height that is a portion of the height of said substantially annular wall, and wherein the height of said first air flow opening is greater than the height of said second air flow opening.

165. The bumer of claim 164, further comprising a third air flow opening extending between said substantially annular air gathering chamber and Said substantially annular air-flow mixing chamber, and having a third height that is a portion of the height of said substantially annular wall, and wherein the height of said first air flow opening is greater than the height of said third air flow opening, and the height of said second air flow opening is greater than the height of said third air flow opening.

166. The burner of claim 165, further comprising a fourth air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a fourth height that is a portion of the height of said substantially annular wall, and wherein the height of said first air flow opening is greater than the height of said fourth air flow opening, the height of said second air flow opening is greater than the height of said fourth air flow opening, and height of said third air flow opening is greater than the height of said fourth air flow opening.

167. The burner of claim 166, wherein said substantially annular flow passage is substantially circular in shape.

168. The burner of claim 167, wherein said substantially annular wall is substantially circular in shape.

169. The burner of claim 168, wherein said wherein the height of said substantially annular flow passage and the height of said air gathering chamber are similar one to the other.

170. The burner of claim 168, wherein said substantially annular air gathering chamber generally surrounds said substantially annular air-flow mixing chamber.

171. The burner of claim 170, wherein said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber are substantially longitudinally aligned one with the other along said longitudinal axis.

172. The burner of claim 168, wherein said at least one air inlet is disposed rearwardly of said substantially annular air gathering chamber.

173. The burner of claim 1 , wherein said main body comprises an air-flow-controlling rear housing and an outer housing.

174. A burner comprising:

a main body; at least one air inlet;

a mixing chamber;

a fuel passageway having a fiiel receiving inlet, and a fuel emitting outlet for delivering fuel to said mixing chamber;

a first air flow channel having an inlet in fluid communication with said at least one air inlet, and an outlet disposed adjacent said fuel emitting outlet, for delivering air to said mixing chamber; and,

a substantially annular air gathering chamber in fluid communication with said at least one air inlet, a substantially annular air-flow mixing chamber, a substantially annular wall generally dividing said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, a first air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a first height that is a portion of the height of said substantially annular wall.

175. The burner of claim 174, further comprising an air accumulator chamber interposed in fluid communication between said at least one air inlet and said first air flow channel,

176. The burner of claim 175, wherein the cross-sectional area of said air egress is narrower than the cross-sectional area of said air accumulator chamber.

177. The burner of claim 174, wherein substantially all of said first air flow channel is oriented obliquely to said longitudinal axis.

178. The burner of claim 177, wherein said first air flow channel is helically shaped.

179. The burner of claim 174, wherein the ratio of the cross-sectionαl area of said inlet of said first air flow channel to the cross-sectional area of said outlet of said first air flow channel is about 1.6 to 1.

180. The burner of claim 174, wherein the cross-sectional area of said first air flow channel decreases from said inlet to said outlet.

181. The burner of claim 180, wherein the width of said first air flow channel decreases from said inlet to said outlet.

182. The burner of claim 181, wherein me depth of said first air flow channel decreases from said inlet to said outlet

183. The burner of claim 174, further comprising a fuel nozzle disposed within said main body, said fuel nozzle having said fuel passageway, said fuel receiving inlet and said fuel emitting outlet.

184. The burner of claim 183, wherein said fuel nozzle has a front end and a back end and is substantially straight.

185. The burner of claim 184, wherein said fuel passageway is substantially straight.

186. The burner of claim 183 , wherein said first air flow channel is disposed on the exterior of said fuel nozzle.

187. The burner of claim 183, further comprising a second air flow channel.

188. The burner of claim 187, wherein said first airflow channel and said second air flow channel are substantially parallel one to another.

189. The burner of claim 188, wherein said first air flow channel and said second air flow channel are helically shaped.

190. The burner of claim 189, wherein said inlet of said second air flow channel has a cross-sectional area that is larger than the cross-sectional area of said outlet of said second air flow channel.

191. The burner of claim 190, wherein the ratio of the cross-sectional area of said inlet of said first air flow channel to the cross-sectional area of said outlet of said first air flow channel is about 1.6 to 1.

192. The burner of claim 190, wherein the cross-sectional area of said first air flow channel decreases from said inlet to said outlet.

193. The burner of claim 192, wherein the width of said first air flow channel decreases from said inlet to said outlet.

194. The burner of claim 193, wherein the depth of said first air flow channel decreases from said inlet to said outlet.

195. The burner of claim 187, further comprising a third air flow channel, a fourth air flow channel and a fifth air flow channel.

196. The burner of claim 195, wherein said first air flow channel, said second air flow channel, said third air flow channel, said fourth air flow channel and said fifth air flow channel are substantially parallel one to another.

197. The burner of claim 196, wherein said third air flow channel, said fourth air flow channel and said fifth air flow channel are helically shaped.

198. The burner of claim 184, wherein said fuel nozzle comprises an elongate main body having an inlet end and an outlet end, and wherein said fuel receiving inlet is disposed at said inlet end and said fuel emitting outlet is disposed at said outlet end.

199. The burner of claim 198, wherein said elongate main body comprises a narrow back ponton and a wider front portion.

200. The burner of claim 199, wherein said elongate main body of said fuel nozzle further comprises a sloped portion interconnecting said narrow back portion and said wider front portion.

201. The burner of claim 200, wherein said sloped portion of said fuel nozzle engages in sealing contact with a co-operating receiving surface on said main body.

202. The burner of claim 201, wherein said fuel nozzle comprises a rear portion that is threaded to engage a co-operating nut to thereby retain said fuel nozzle on place in said main body.

203. The burner of claim 174, further comprising a second air inlet in said main body, and wherein said at least one helically shaped air flow channel is in fluid communication with said second air inlet.

204. The burner of claim 174, further comprising a fuel nozzle tip mounted in removable and replaceable relation in the front end of said elongate main body of said fuel nozzle.

205. The burner of claim 174, wherein said mixing chamber is aligned along said longitudinal axis with said fuel passageway.

206. The burner of claim 174, further comprising a combustion chamber extension mounted on said main body so as to extend forwardiy from the front end of said main body.

207. The burner of claim 206, wherein said combustion chamber extension is mounted in removable and replaceable relation on said outer housing.

208. The burner of claim 174, further comprising a substantially annular air gathering chamber in said main body and in fluid communication with said at least one air inlet, a substantially annular air-flow mixing chamber within said main body, it substantially annular wall generally dividing said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, a first air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a first height that is a portion of the height of said substantially annular wall, and a second air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a second height that is a portion of the height of said substantially annular wall, and wherein the height of said first air flow opening is greater than the height of said second air flow opening.

209. The burner of claim 208, further comprising a third air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a third height that is a portion of the height of said substantially annular wall, and wherein the height of said first air flow opening is greater than the height of said third air flow opening, and the height of said second air flow opening is greater than the height of said third air flow opening.

210. The burner of claim 209, further comprising a fourth air flow opening extending between said substantially annularair gathering chamber and said substantially annular air-flow mixing chamber, and having a fourth height that is a portion of the height of said substantially annular wall, and wherein the height of said first air flow opening is greater than the height of said fourth air flow opening, the height of said second air flow opening is greater than the height of said fourth air flow opening, and height of said third air flow opening is greater than the height of said fourth air flow opening.

21 ! . The burner of claim 210, wherein said substantially annular flow passage is substantially circular in shape.

212. The burner of claim 211, wherein said substantially annular wall is substantially circular in shape.

213. The burner of claim 212, wherein said wherein the height of said substantially annular flow passage and the height of said air gathering chamber are similar one Io lhe other.

214. The burner of claim 212, wherein said substantially annular air gathering chamber generally surrounds said substantially annular air-flow mixing chamber.

215. The burner of claim 214, wherein said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber are substantially longitudinally aligned one with the other along said longitudinal axis.

216. The burner of claim 212, wherein said at least one air inlet is disposed rearwardly of said substantially annular air gathering chamber.

217. The burner of claim 174, wherein said main body comprises an air- flow-controlling rear housing and an outer housing.

218. A burner comprising:

a main body;

at least one air inlet;

a mixing chamber;

a second air flow channel having an inlet in fluid communication with said at least one air inlet, and an outlet disposed adjacent said fuel emitting outlet, for delivering air to said mixing chamber; wherein said first air flow channel and said second air flow channel generally surround said fuel passageway.

219. The burner of claim 218, further comprising an air accumulator chamber interposed in fluid communication between said at least one air inlet and said first air flow channel.

220. The burner of claim 219, wherein the cross-sectional area of said air egress is narrowerthan the cross-sectional area of said air accumulator chamber.

221. The burner of claim 218, wherein substantially all of said first air flow channel is oriented obliquely to said longitudinal axis.

222. The burner of claim 221, wherein said first air flow channel is helically shaped.

223. The burner of claim 218, wherein the ratio of the cross-sectional area of said inlet of said first air flow channel to the cross-sectional area of said outlet of said first air flow channel is about 1.6 to I.

224. The burner of claim 218, wherein the cross-sectional area of said first air flow channel decreases from said inlet to said outlet.

225. The burner of claim 224, wherein the width of said first air flow channel decreases from said inlet to said outlet.

226. The burner of claim 225, wherein the depth of said first air flow channel decreases from said inlet to said outlet.

227. The burner of claim 218, further comprising a fuel nozzle disposed within said main body, said fuel nozzle having said fuel passageway, said fuel receiving inlet and said fuel emitting outlet.

228. The burner of claim 227, wherein said fuel nozzle has a front end and a back end and is substantially straight.

229. The burner of claim 228, wherein said fuel passageway is substantially straight

230. The burner of claim 227, wherein said first air flow channel is disposed on the exterior of said fuel nozzle.

231. The burner of claim 227, fiuther comprising a second air flow channel.

232. The burner of claim 231 , wherein said first air flow channel and said second air flow channel arc substantially parallel one to another.

233. The burner of claim 232, wherein said first air flow channel and said second air flow channel are helically shaped.

234. The burner of claim 233, wherein said inlet of said second air flow channel has a cross-sectional area that is larger than the cross-sectional area of said outlet of said second air flow channel.

235. The burner of claim 234, wherein the ratio of the cross-sectional area of said inlet of said first airflow channel to the cross-sectional area of said outlet of said first air flow channel is about t .6 to 1.

236. The burner of claim 235, wherein the cross-sectional area of said first air flow channel decreases from said inlet to said outlet.

237. The burner of claim 236, wherein the width of said first air flow channel decreases from said inlet to said outlet.

238. The burner of claim 237, wherein the depth of said first air flow channel decreases from said inlet Io said outlet.

239. The burner of claim 231 , further comprising a third air flow channel, a fourth air flow channel and a fifth air flow channel.

240. The burner of claim 239, wherein said first air flow channel, said second air flow channel, said third air flow channel, said fourth air flow channel and said fifth air flow channel are substantially parallel one to another.

241. The burner of claim 240, wherein said third air flow channel, said fourth air flow channel and said fifth air flow channel are helically shaped.

242. The burner of claim 237, wherein said fuel nozzle comprises an elongate main body having an inlet end and an outlet end, and wherein said fuel receiving inlet is disposed at said inlet end and said fuel emitting outlet is disposed at said outlet end.

243. The burner of claim 242, wherein said elongate main body comprises a narrow back portion and a wider front portion.

244. The burner of claim 243, wherein said elongate main body of said fuel nozzle further comprises a sloped portion interconnecting said narrow back portion and said wider front portion.

245. The burner of claim 244, wherein said sloped portion of said fuel nozzle engages in sealing contact with a co-operating receiving surface on said main body.

246. The burner of claim 245, wherein said fuel nozzle comprises a rear portion that is threaded to engage a co-operating nut to thereby retain said fuel nozzle on place in said main body.

247. The burner of claim 218, further comprising a second air inlet in said main body, and wherein said at least one helically shaped air flow channel is in fluid communication with said second air inlet.

248. The burner of claim 21 S, further comprising a fuel nozzle tip mounted in removable and replaceable relation in the front end of said elongate main body of said fuel nozzle.

249. The burner of claim 218, wherein said mixing chamber is aligned along said longitudinal axis with said fuel passageway.

250. The burner of claim 218, further comprising a combustion chamber extension mounted on said main body no as to extend forwardly from the front end of said main body.

251. The burner of claim 250. wherein said combustion chamber extension is mounted in removable and replaceable relation on said outer housing.

252. The burner of claim 2 I S, further comprising a substantially annular air gathering chamber in said main body and in fluid communication with said at least one air inlet, a, substantially annular air-flow mixing chamber within said main body, a substantially annular wall generally dividing said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, a first air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a first height that is a portion of the height of said substantially annular wall, and a second air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a second height that is a portion of the height of said substantially annular wall, and wherein the height of said first air flow opening is greater than the height of said second air flow opening,

253. The burner of claim 252, further comprising a third air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a third height that is a portion of the height of said substantially annular wall, and wherein the height of said first air flow opening is greater than the height of said third air flow opening, and the height of said second air flow opening is greater than the height of said third air flow opening.

254. The burner of claim 253, further comprising a fourth air flow opening extending between said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber, and having a fourth height that is a portion of the height of said substantially annular wall, and wherein the height of said first air flow opening is greater than the height of said fourth air flow opening, the height of said second air flow opening is greater than the height of said fourth air flow opening, and height of said third air flow opening is greater than the height of said fourth air flow opening.

255. The burner of claim 254, wherein said substantially annular flow passage is substantially circular in shape.

256. The burner of claim 255, wherein said substantially annular wall is substantially circular in shape.

257. The burner of claim 256, wherein said wherein the height of said substantially annular flow passage and the height of said air gathering chamber are similar one to the other.

258. The burner of claim 256, wherein said substantially annular air gathering chamber generally surrounds said substantially annular air-flow mixing chamber.

259. The burner of claim 258, wherein said substantially annular air gathering chamber and said substantially annular air-flow mixing chamber are substantially longitudinally aligned one with the other along said longitudinal axis.

260. The burner of claim 256, wherein said at least one air inlet is disposed rearwardJy of said substantially annular air gathering chamber.

261. The burner of claim 218, wherein said main body comprises an air-flow-conttolling rear housing and an outer housing.