Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
  • F23D14/34—Burners specially adapted for use with means for pressurising the gaseous fuel or the combustion air
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
  • F23C5/00—Disposition of burners with respect to the combustion chamber or to one another; Mounting of burners in combustion apparatus
  • F23C5/08—Disposition of burners
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
  • F23D14/02—Premix gas burners, i.e. in which gaseous fuel is mixed with combustion air upstream of the combustion zone
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
  • F24H1/00—Water heaters, e.g. boilers, continuous-flow heaters or water-storage heaters
  • F24H1/22—Water heaters other than continuous-flow or water-storage heaters, e.g. water heaters for central heating
  • F24H1/34—Water heaters other than continuous-flow or water-storage heaters, e.g. water heaters for central heating with water chamber arranged adjacent to the combustion chamber or chambers, e.g. above or at side
  • F24H1/36—Water heaters other than continuous-flow or water-storage heaters, e.g. water heaters for central heating with water chamber arranged adjacent to the combustion chamber or chambers, e.g. above or at side the water chamber including one or more fire tubes

Definitions

• the present invention relates generally to a free standing burner for general burner use as well as to the design of a water heater or boiler for residential, commercial and industrial use which utilizes such an improved burner to supply heat to such devices.
• Water heaters and boilers typically have a water heater tank, often of the vertical tube type which utilizes fire tubes located above a combustion chamber.
• a number of the typical prior art gas, oil or gas/oil fired water heaters feature a non-pressurized, external combustion chamber which was typically located on the bottom exterior of the water heater.
• Vertical shell or V-shell heat exchangers of the above type are well known in the industry.
• typical water heater construction has provided for the flow of hot gas through a series of tubes mounted in vertical fashion between top and bottom transverse wall sections or support plates within the water heater tank.
• the products of combustion from the combustion chamber pass vertically upward through the open interiors of the vertical tubes and out a flue outlet.
• Water was circulated into and out of a chamber in the prior art devices located between the transverse wall sections. The water contacted and circulated about the exterior of the vertical tubes to effect heat transfer to heat the water.
• a low pressure natural gas stream is being introduced into a forced draft air supply fed by a power blower at a higher pressure.
• One function of the typical burner design is to introduce the flow of relatively lower pressure natural gas into the relatively higher pressure forced air stream, the gas mixture being passed through some sort of restriction or orifice.
• water heaters and boilers form nitrogen oxides during combustion. Nitrogen oxide emissions are air pollutants. Various state and federal agencies regulate the amount of nitrogen oxides, or NO x , in vented gases. Tightening state and federal regulations for emissions requirements warrant the effort to find new ways to remove or prevent the formation of nitrogen oxides in combustion processes to avoid further harmful effects on the environment.
• a need also exists for an improved vertical tube water heater design having vertical tube components and an improved burner which increase the overall efficiency of the apparatus in heating water.
• a need exists for such an apparatus which is simple in design and relatively easy to manufacture.
• the present invention concerns an inwardly firing burner design for general burner use on gas burner applications where benefit is obtained from firing directly into a heat exchanger without the need for a separate combustion chamber, where combustion is largely completed within the burner or where low NOx operation is desired.
• the burner has an outer body assembly, the outer body having a transverse wall opening therein for communication with a blower, the outer body having an interior and one or more . end openings.
• An inner chamber assembly is mounted within the interior of the burner outer body, the inner chamber having largely opposing sidewalls.
• the inner chamber assembly forms a peripheral seal with respect to the openings of the outer body, thereby forming an open internal region which constitutes a combustion region for the burner and one or more end openings for exhausting the products of combustion.
• the burner also includes an intermediate chamber assembly having sidewalls which allow the assembly to be positioned about the inner chamber and within the interior of the outer body.
• the walls of the intermediate chamber assembly also have one or more openings which are located between the sealed region formed between the outer body and the inner chamber, whereby a distributed flow path is created for gases passing from the blower, between the interior of the outer body and the sidewalls of the inner chamber.
• An igniter element is operatively associated with the outer body for igniting air and fuel supplied to the interior of the inner chamber to thereby produce products of combustion for heating.
• the igniter element is at least one electrode mounted on the outer body assembly.
• the sidewalls of the inner chamber which is mounted within the interior of the burner outer body, are formed of a heat resistant material.
• Another distinguishing characteristic of the present burner design is the fact that the sidewalls of the inner chamber, which is mounted within the interior of the burner outer body, are in the majority facing inward, as will be explained more fully in the detailed description which follows.
• the improved burner of the invention mixes air and gas in the presence of a flame to create products of combustion, and wherein the inwardly firing design of the burner contains a majority of the flame within the burner itself, thereby eliminating the need for a separate refractory lined combustion chamber.
• the inwardly firing burner allows combustion to be established and largely completed within an envelope defined by the outer body of the burner itself, thereby resulting in a self-chambered burner design.
• the burner of the present invention meets the previously described needs by providing a burner design for a water heater in which combustion is established and completed within the envelope of the burner itself.
• a combustion chamber-less burner which is needed to complete combustion prior to the heat exchange tubes is eliminated.
• the concept might also be expressed as providing a combustion chamber-less burner or a self-chambered burner.
• a water heating tank is provided having generally cylindrical sidewalls with opposing closed ends which define a closed tank interior.
• a plurality of fire tubes are located within the closed tank interior, each fire tube having an open interior for conducting products of combustion.
• a blower/burner assembly is mounted at a selected one of the opposing tank ends for igniting a gas, oil, or gas/oil fuel mixture and producing products of combustion which travel within the open interiors of the fire tubes for heating water which surrounds the fire tubes within the tank interior.
• a flue collector chamber is located on a selected end of the tank for collecting and exhausting the products of combustion from the fire tubes.
• the burner which is used with the water heater tank is a specially designed burner which features the previously described inwardly firing design which eliminates the need for an external combustion chamber mounted on the exterior of the water heater tank, as in the prior art designs.
• the inwardly firing design of the burner contains a majority of the flame within the burner itself, thereby eliminating the need for refractory materials and a separate refractory lined combustion chamber.
• the inwardly firing burner when incorporated into an improved water heater or boiler design, allows combustion to be established and completed within an envelope defined by the outer body of the burner itself, thereby resulting in a combustion chamber-less or self-chambered burner design.
• the burner of the burner/blower assembly of the invention has a cylindrical outer body, the outer body having a transverse wall opening therein for communication with the blower, the outer body having an interior and first and second oppositely arranged, end openings, the first end of the burner being mounted on the water heater tank in communication with the interior of the fire tubes.
• An inner cylindrical chamber is mounted within the interior of the burner outer body, the inner cylindrical chamber forming a peripheral sealed end region at the first end opening of the outer body.
• the inner cylindrical chamber has sidewalls which form an open internal region which constitutes a combustion region for the burner and an end opening for exhausting the products of combustion to the fire tubes of the associated water heating tank.
• the preferred burner assembly of the invention further comprises an ignition cap assembly.
• the ignition cap assembly includes a cylindrical body portion having cylindrical sidewalls. The sidewalls have a selected external diameter which allows the cylindrical body portion to be received about the inner cylindrical chamber and within the interior of the cylindrical outer body.
• the sidewalls of the cap assembly also have a predetermined depth which is less than a corresponding depth of the cylindrical sidewalls of the outer body, thereby creating a gap with respect to the sealed peripheral region formed at the first end opening of the burner.
• the cap assembly also has a lid portion which seats upon and seals with the second end opening of the cylindrical outer body, whereby a serpentine flow path is created for gases passing from the blower, between the interior of the outer body and the cylindrical body portion of the cap assembly and between the sidewalls of the cap assembly and the sidewalls of the inner cylindrical chamber.
• An igniter element operatively associated with the cap assembly, is provided for igniting air and fuel supplied to the interior of the inner cylindrical chamber to thereby produce products of combustion for heating water contained within the associated water heater tank.
• the igniter element comprises a pair of electrodes mounted on the lid region of the cap assembly.
• the lid portion of the cap assembly can conveniently comprise a planar member which is of a greater relative outer diameter than that of the outer body, whereby the lid portion forms an outwardly extending flange region which seats upon and seals with the second end opening of the cylindrical outer body.
• Figure 1 is a simplified, side view of a vertical tube water heater having the improved burner of the invention mounted thereon.
• Figure 2 is an isolated, side view of the blower/burner assembly of Figure 1 , portions of the burner sidewalls having been broken away for ease of illustration.
• FIG 3 is a close-up view of the burner of Figure 2, showing the flow of gases through the burner in greater detail.
• Figure 4 is an exploded perspective view of the burner of the invention.
• Figure 5 is a view of a prior art water heater having an externally mounted burner on the combustion chamber located on the bottom of the tube assembly.
• Figure 6 is a view of another prior art water heater design, again featuring an externally mounted burner, where the combustion chamber is located on the top of the tube assembly, rather than on the bottom.
• the improved burner assembly of the invention can conceivably be incorporated into a large variety of end applications for gas burners in both the general consumer and commercial and industrial settings.
• the improved device of the invention could be used, for example, in such diverse applications as cooking ovens, grills, gas freestanding stoves, cook-tops, rotisseries and outdoor grills, to name a few.
• one end application or appliance which could advantageously incorporate a burner of the general type under consideration is in the area of water heaters and boilers.
• the discussion which follows largely uses the example of a commercial water heater to illustrate the principles of the invention.
• FIG. 5 shows a prior art water heater assembly, which in this case is a vertical tube water heater apparatus, designated generally as 11.
• the water heater apparatus 11 includes a water heating tank 13 having generally cylindrical sidewalls with upper and lower transverse wall sections or support plates 15, 17.
• a combustion chamber or fire box 19 is located on the bottom of the apparatus and includes a power blower/burner 21 for creating products of combustion within the fire box 19.
• the blower/burner 21 could be, for example, a gas fired, "FIREPOWER" forced draft burner commercially available from PVI Industries, Inc., of Fort Worth, Tex.
• a plurality of vertically arranged fire tubes 23 are located within a closed tank interior 25.
• Each fire tube 23 has an open interior for conducting products of combustion from the fire box 19 upwardly toward a flue collector (not shown) for exhausting the products of combustion from the device.
• Water is circulated within the tank interior 25 between a water inlet and a water outlet (not shown). The water contacts the exterior surfaces of the fire tubes 23 to effect heat transfer.
• FIG 6 is a side, partial sectional view of a prior art water heater having a top mounted combustion chamber, designated generally as 27.
• the water heater apparatus 27 again includes a water heating tank 29 having generally cylindrical sidewalls with upper and lower ends 31 , 33. Each of the initially open upper and lower ends 31 , 33 is closed by an upper and lower transverse wall section 35, 37, respectively, to define a closed interior 39 for the tank.
• the upper and lower transverse wall sections 35, 37 are parallel in the embodiment of the invention of Figure 2.
• the tank 29 also has a water inlet (shown in dotted lines as 41 in Figure 2) which admits water to the lower region of the tank interior and a water outlet 43 which allows water to flow out of the tank interior from the upper region thereof.
• a plurality of vertically arranged fire tubes 45 are located within the tank closed interior 39. Each fire tube has an open interior and an upper end 47 and a lower end 49. There may be, for example, thirty-six such fire tubes within the closed tank interior arranged in concentric circles.
• the upper and lower tube ends 47, 49 are supported by means of the upper and lower transverse wall sections 35, 37, the tubes being welded within appropriate openings provided in the transverse wall sections.
• a combustion chamber (53 in Figure 6) is mounted on the upper end 31 of the water heating tank 29 for providing products of combustion to the open interiors of the fire tubes 45.
• the combustion chamber 53 includes insulation 55 which can be, for example, of a suitable refractory material.
• a blower/burner 57 is mounted on a sidewall of the combustion chamber 53 and communicates with the chamber interior 59 for supplying products of combustion thereto.
• the tank 29 is also insulated by a suitable insulating material 61 and includes a flue collector chamber 63 which is located at the bottom end 33 of the water heating tank for collecting and exhausting the products of combustion from the vertically arranged fire tubes 45.
• a condensate drain 64 can be used to remove any collected condensate from the flue collector chamber 63.
• a draft inducing means such as induction blower 65, driven by blower motor 67, pulls the products of combustion from the chamber interior 59 through the open interior of the vertical fire tubes 45 and through the flue collector chamber 63 for exhaustion from the apparatus.
• the exhausted flue gases may be passed to the atmosphere or may be conveyed through an exhaust pipe to another location.
• FIG. 1 there is shown a water heater assembly 71 with a tank arrangement which generally corresponds to the tank arrangement described in Figures 5 and 6 of the drawings.
• a water heating tank 73 has generally cylindrical sidewalls with upper and lower ends 75, 77, respectively. Each of the tank ends 75, 77 is closed by means of a transverse wall section 79, 81 to define a closed tank interior 83.
• a plurality of fire tubes such as tubes 85, 87, are, in this case, vertically arranged to connect between the upper and lower transverse wall section 79, 81.
• Each fire tube e.g., fire tube 87, has an open interior 89 for conducting products of combustion. While the invention is illustrated with respect to a vertical tube water heater, it will be appreciated from the discussion which follows that other orientations, such as a horizontal tank configuration, would work as well.
• a blower and burner assembly designated generally as 91 , is mounted on a selected one of the upper and lower ends 75, 77, respectively, of the water heating tank for providing products of combustion to the open interiors of the fire tubes.
• a flue collector chamber 93 is typically located on the respective end of the tank opposite the burner assembly 91 for collecting and exhausting the products of combustion from the vertically arranged fire tubes 85, 87.
• the flue collector could be on the same end of the tank as the burner assembly.
• FIGS 2-4 illustrate the improved burner assembly of the invention in greater detail.
• the burner assembly is an inwardly firing burner which illuminates the need for a separate, external combustion chamber (such as the combustion chamber 53 in Figure 6) mounted on the exterior or the water heater tank.
• the blower/burner assembly 91 shown in Figure 2, ignites an air-fuel mixture in the presence of a spark or flame to create products of combustion.
• benefit is obtained from the firing directly into a heat exchanger without the need for a separate combustion chamber, where combustion is largely completed within the burner, or where low NO x operation is desired.
• the illustrated burner 95 has a cylindrical outer body 97 formed of a suitable metal.
• the outer body has a transverse wall opening 99 for communication with a conventional power blower 101.
• the outer body 97 has an interior 103 and one or more, in this case, first and second oppositely arranged, end openings 105, 107.
• the first end 105 of the burner 95 is mounted on the water heater tank in communication with the interior of the fire tubes, as shown in Figure 1.
• the illustrated burner is shown as having a cylindrical outer body, it will be appreciated that the outer body could assume a variety of shapes, depending upon the end application. For example, the outer body could be rectangular, conical, hemispherical, etc. and still serve the necessary air/fuel capturing function.
• an inner cylindrical chamber 109 is mounted within the interior 103 of the burner outer body 97.
• the inner cylindrical chamber 109 has cylindrical sidewalls 111 which form an open internal region 113 (see Figure 4) which constitutes a combustion region for the burner.
• the inner cylindrical chamber 109 also has an end opening 115 ( Figure 3) for exhausting the products of combustion to the fire tubes of the associated water heating tank.
• the inner cylindrical chamber 109 is preferably formed of a heat resistant material. It will also be evident that, depending upon the end application, it may be possible to maintain the same burner performance and basic benefits of the inwardly firing burner even when the inner combustion region or chamber has a shape other than cylindrical.
• the illustrated water heater assembly further includes an ignition cap assembly.
• the cap assembly comprises a cylindrical body portion 117 formed of a suitable metal and having cylindrical sidewalls (119 in Figure 4).
• the sidewalls 119 are of a selected external diameter which allows the cylindrical body portion 117 to be received about the inner cylindrical chamber 109 and within the interior 103 of the cylindrical outer body 97.
• the sidewalls 119 of the cap assembly also have a predetermined depth, illustrated as "d” in Figure 4.
• the depth "d” is less than a corresponding depth of the cylindrical sidewalls of the outer body 97, thereby creating a gap ("g” in Figure 3) with respect to the sealed peripheral region formed at the first end opening 105 of the burner.
• the "sealed peripheral region” is indicated generally at 121 in Figure 3 and is formed between a flange region on the inner cylindrical chamber 109 and a mating flange region formed on the cylindrical outer body 97.
• the cap assembly also has a lid portion 123 which seats upon and seals with the second end opening 107 all the cylindrical outer body.
• the gap (g" in Figure 3) together with the concentric spacing of the ignition cap assembly and the inner cylindrical chamber sidewalls, forms a serpentine flow path through the burner.
• the flow path which is created allows gas to pass from the blower/burner, between the interior 103 of the outer body and the cylindrical body portion 119 of the cap assembly, and between the sidewalls of the cap assembly and the sidewalls 11 of the inner cylindrical chamber as the gas passes through the burner interior.
• the "serpentine" flow path for the hot gases is illustrated by the arrows in Figure 3.
• the sidewalls 119 of the cap assembly are a type of "baffle" which creates an intermediate chamber having sidewalls which allow the assembly to be positioned about the inner chamber and within the interior of the outer body.
• the walls of the intermediate chamber then have one or more openings (such as the openings 122, 124 in Figure 3) between the sealed region formed between the outer body and the inner chamber, whereby a distributed flow path is created for gases passing from the blower, between the interior of the outer body and the sidewalls of the inner chamber.
• An igniter element 125 is operatively associated with the outer body and cap assembly for igniting air and fuel supply to the interior of the inner cylindrical chamber 109 to thereby produce products of combustion for heating water contained within the associated water heater tank.
• the igniter element 125 comprises a pair of electrodes 127 mounted on the lid region or portion of the cap assembly.
• the lid portion 123 of the cap assembly is a planar member which is of greater relative outer diameter than that of the outer body 97, whereby the lid portion forms an outwardly extending flange region (129 in Figure 3) which seats upon and seals with the second end opening 107 of the cylindrical outer body 97.
• the electrodes shown in Figure 3, will typically be connected to conventional circuitry for producing a timed spark on the interior surface of the cap assembly for igniting the fuel and air mixture to produce products of combustion.
• the electrodes themselves and the accompanying electrical circuitry used to provide a timed spark are conventional in the industry and will be familiar to those skilled in the art. While the invention is described in terms of a flame being lit by a spark igniter, other types of hot surface or other igniter systems could be utilized.
• the lid portion 123 of the cap assembly is, in this case, lined with a refractory material 126.
• a refractory material 126 While the inwardly firing design of the present burner contains a significant portion of the flame within the burner itself, the portion of the flame within the burner varies by end application and the available back pressure. While the illustrated burner includes the refractory material 126, other variations of the design may eliminate the need for a refractory, such as in the case of a conical inner combustion chamber, for example.
• the igniter element While the igniter element is shown as being installed within the lid portion of the cap assembly, it could also enter from the outer body to the inner combustion chamber at almost any location within or adjacent that chamber. Thus, the igniter element could enter through the side of the burner and the sidewall of the inner combustion chamber, if that arrangement provided a more convenient design. If the illustrated, cylindrical burner was altered to have two heat outlets or openings instead of one, as described above, the ignition source might be located outside one of these openings. While such a design might not be practical where the burner outlet is placed against the sidewall of an appliance heat exchanger, it might well be desirable in a two heat outlet design. Also, if a differently shaped combustion chamber is utilized, the end cap may be eliminated.
• the blower/burner assembly 91 ( Figure 1 ) provides a fuel/air mixture within the interior of the inner cylindrical chamber 109.
• a timed spark is provided by the electrodes 127 to produce combustion of fossil fuel, such as a natural gas, within the interior of the inner chamber 109.
• the air/fuel mixture path is from the blower nozzle (131 in Figure 3) through the transverse wall opening 99 and about the serpentine flow path illustrated by the arrows in Figure 3 to the interior of the inner cylindrical chamber 109.
• a timed spark is provided to the burner by means of the electrodes 127 to produce combustion of fossil fuel, such as a natural gas, within the combustion region.
• the burner of the invention has an inwardly firing design which eliminates the need for an external combustion chamber mounted on the exterior of the water heater tank.
• the inwardly firing design of the burner contains a majority of the flame within the burner itself, thereby eliminating the need for refractory materials and a separate refractory lined combustion chamber.
• the inwardly firing nature of the burner allows combustion to be established and completed within an envelope defined by the outer body of the burner itself, thereby resulting in a self-chambered design.
• the self-chambered burner of the invention overcomes problems associated with the prior art designs in which the nozzles of the prior art burners tended to be destroyed relatively quickly because of the high temperatures which they encountered within the refractory lined combustion chambers.
• the new burner design is relatively simple and economical to manufacture and can readily be adapted to a number of existing water tank installations.
• the burner design is simple in nature, as compared to the relative complexity and cost of presently available burners and stack devices that produce equivalent NO x levels.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Gas Burners (AREA)
• Spray-Type Burners (AREA)
• Instantaneous Water Boilers, Portable Hot-Water Supply Apparatuses, And Control Of Portable Hot-Water Supply Apparatuses (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=40796591

Family Applications (1)

Country Status (5)

Families Citing this family (17)

Family Cites Families (35)

• 2007
  • 2007-12-26 US US12/005,181 patent/US20090165733A1/en not_active Abandoned
• 2008
  • 2008-04-10 CA CA2629127A patent/CA2629127C/en not_active Expired - Fee Related
  • 2008-07-17 WO PCT/US2008/008753 patent/WO2009082415A1/en active Application Filing
  • 2008-07-17 EP EP08794563A patent/EP2235447A1/en not_active Withdrawn
  • 2008-09-18 MX MX2008011917A patent/MX2008011917A/es unknown

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events