Bushing for a burner to reduce combustion byproducts and oil dripping

Abstract

A combustion head assembly for a burner that reduces combustion byproduct and oil pooling on a flame ring stabilizer or air diffuser element during normal operational cycling. The polymeric bushing directs away or prevents a non-combusted fuel in the fuel line interior portion from the nozzle end after a combustion cycle, and is fabricated from a polymeric material having thermal / electrical insulating properties, which is resistant to decomposition, dissolution, or breakdown when exposed to No. 2 fuel oil, biodiesel fuel oil, such as fluoropolymers, including PTFE (Teflon), fluorinated ethylene propylene (FEP), perfluoroalkoxy (PFA), ethylene-based fluoropolymers (ETFE / ECTFE), and / or polyvinylidene fluoride (PVDF), polyether ether ketones (PEEK), polyphenylene sulfide (PPS), and / or fluoroelastomers (FKM), or acrylonitrile butadiene styrene (ABS). The polymeric bushing is situated within a fuel line interior portion behind a nozzle element, having a channel or bore extending from end to end and in fluid communication with the nozzle element opening.

Description

BACKGROUND OF THE INVENTION1. Field of the Invention

[0001] The present invention relates to commercial and residential petrodiesel fuel burners, and more particularly, to petrodiesel fuel burners using biodiesel fuels and biodiesel blended fuels.2. Description of Related Art

[0002] Presently, millions of homes in the US are heated using petrodiesel fuel products such as No. 2 fuel oil. Heating systems utilizing this fuel source typically include petrodiesel fuel burners (“burners”) mounted on boilers, furnaces, and water heaters. During operation, a fuel is ignited within the burner of the appliance for the production of heat energy for the distribution into the apparatus (e.g., water heater) or living spaces by way of ductwork and / or piping within the home.

[0003] To combat the environmental concerns associated with petrodiesel, the residential and commercial oil heating industry has begun the implementation of biodiesel fuels, which often consist of long-chain fatty acid esters derived from plants and animals (“biofuel”). Advantageously, biodiesel fuel is compatible within existing petrodiesel fuel burners without modification if the biodiesel fuel is blended with petrodiesel fuel. Biodiesel blends of up to B20 (80% No. 2 fuel oil mixed with 20% biodiesel fuel) are now readily available. The oil heating industry plans to continue increasing the blend levels—with the ultimate goal of reaching B100 (100% biodiesel fuel).

[0004] Renewable diesel may also be implemented as an alternative fuel. Notably, renewable diesel and biodiesel are not the same type of fuel. Renewable diesel, previously known as green diesel, is a hydrocarbon produced most often by hydrotreating and also via gasification, pyrolysis, and other biochemical and thermochemical technologies. In contrast, biodiesel is a mono-alkyl ester produced via transesterification. It is possible that a blended form of renewable diesel and biofuel may be considered for implementation in a burner.

[0005] Biofuel is most commonly manufactured from soybeans or recycled restaurant grease, and other plant and animal fat, in lieu of petroleum. When heating a home, it produces less sulfur dioxide, hydrocarbons, and air toxins, making it a cleaner heating solution. It is renewable, sustainable, and provides for lower emissions.

[0006] Biofuel up to B20 and beyond generally do not require equipment changes or settings. Moreover, according to the National Oilheat Research Alliance (“NORA”), the use of biodiesel fuel reduces greenhouse gas emissions by 50% to 85% compared to petroleum diesel. Blends over B20 may require some minor burner upgrades or setting changes, where the costs of such changes are comparatively low with respect to the alternative appliance replacement normally required to resolve combustion byproduct mitigation.

[0007] While many modern burners are designed to manage lower biofuel blends, using higher blends or pure biodiesel (B100) may require more timely system inspections by a professional to ensure compatibility and address potential issues like filter clogging from system gunk, carbon deposits, and / or rubber seal degradation.

[0008] A long-standing issue of burners using No. 2 fuel oil relates to oil drips and combustion byproduct build-up on the combustion head assembly and within the air tube following burner run cycles, and onto the flame ring burner stabilizer (air diffuser). It has been known in the industry that such oil drips can accumulate over time, forming deposits of combustion byproducts on the flame ring burner stabilizer. Oil drips from the nozzle have been a source of carbon build-up and combustion byproducts. If not properly maintained, the accumulation can inhibit proper combustion within the burner which can result in burner malfunction. It has been found that biodiesel blends can be particularly problematic with this issue, as deposits are able to accumulate more immediately than burners using pure No. 2 fuel oil.

[0009] Generally, it is recommended to service burners and the associated appliances annually. This service interval is a critical aspect to the acceptance of biofuel within the industry, as most oil dealers are not staffed to conduct burner service multiple times a year. While one way to address this issue is to run a post purge cycle (keeping the burner fan on at the end of a burner run cycle), there are limits to how long a post purge cycle can run, as it pushes latent heat to the housing exterior that would otherwise stay within the building's envelope. Thus, a need exists in the art to develop an apparatus to stop or minimize the accumulation of combustion by-products on the components of the burner, including the retention ring assembly, air tube, air diffuser, and combustion head. There further exists a need to extend the service life of a burner that utilizes biofuel, such that the normal service interval for burners utilizing No. 2 oil can be adapted for burners using biofuel.SUMMARY OF THE INVENTION

[0010] Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide a combustion head assembly for a burner that reduces combustion byproduct and oil pooling in the air tube and on a flame ring stabilizer or air diffuser element during normal operational cycling.

[0011] Another object of the present invention is to reduce oil pooling and combustion byproduct, and ultimately service cycles, on a burner system that is using biofuel.

[0012] A further object of the invention is to provide a polymeric bushing situated within the fuel line interior portion behind a nozzle element, where the polymeric bushing comprises a channel or bore extending from end to end and in fluid communication with a nozzle element opening, such that the polymeric bushing deters and reduces thermal transfer of heat energy through the fuel line, thereby reducing or eliminating accumulation of oil and combustion byproducts on the flame ring stabilizer or air diffuser element, and reducing or eliminating oil pooling within the air tube.

[0013] Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

[0014] The above and other objects, which will be apparent to those skilled in the art, are achieved in the present invention which is directed to a combustion head assembly for a burner, comprising: a fuel line having a nozzle end and an interior portion; a nozzle element for coupling engagement with the nozzle end, the nozzle element including an opening; a flame ring stabilizer or air diffuser element proximate the nozzle end and in airflow communication with the burner via an air tube; at least one electrode for the ignition of a fuel egressing the nozzle element; and a polymeric bushing situated within the fuel line interior portion behind the nozzle element, the polymeric bushing comprising a channel or bore extending from end to end and in fluid communication with the nozzle element opening; wherein the polymeric bushing deters and reduces thermal transfer of heat energy through the fuel line, thereby reducing or eliminating accumulation of oil and combustion byproducts on the flame ring stabilizer, air tube and / or air diffuser element, and reducing or eliminating oil pooling within the air tube.

[0015] The polymeric bushing may direct away and / or prevent a non-combusted fuel in the fuel line interior portion from the nozzle end after a combustion cycle.

[0016] The polymeric bushing may comprise a polymeric material having thermal insulating properties, which is resistant to decomposition, dissolution, or breakdown when exposed to No. 2 fuel oil, biodiesel fuel oil, and / or combinations thereof.

[0017] The polymeric bushing may comprise fluoropolymers, including PTFE (Teflon), fluorinated ethylene propylene (FEP), perfluoroalkoxy (PFA), ethylene-based fluoropolymers (ETFE / ECTFE), and / or polyvinylidene fluoride (PVDF).

[0018] The polymeric bushing may comprise polyether ether ketones (PEEK), polyphenylene sulfide (PPS), and / or fluoroelastomers (FKM).

[0019] The polymeric bushing may comprise acrylonitrile butadiene styrene (ABS).

[0020] The combustion head assembly may be incorporated within a burner system, wherein the burner system comprises: a burner housing including an air tube and an outlet; the combustion head assembly disposed within the burner air tube; a motor in communication with a fan; an ignitor in communication with the combustion head assembly at least one electrode; a controller in communication with the motor and the ignitor; and a fuel line member for the delivery of a fuel to the combustion head assembly.

[0021] The polymeric bushing may include one or a plurality of slots extending within an end of the polymeric bushing or any portion thereof, wherein the plurality of slots may form a peripherally slotted surface of the polymeric bushing.

[0022] The polymeric bushing may include an end having a crenellation-like design, including a plurality of merlons and embrasures to further prevent fuel clogging and facilitating fuel transfer to a side of the fuel line proximate a fuel line member.

[0023] In a third aspect, the present invention is directed to a burner system comprising: a burner housing including an air tube and an outlet; a combustion head assembly disposed within the burner air tube, the combustion head assembly including: a fuel line having a nozzle end and an interior portion; a nozzle element for coupling engagement with the nozzle end, the nozzle element including an opening; a flame ring stabilizer or air diffuser element proximate the nozzle end and in airflow communication with the air tube; at least one electrode for the combustion of a fuel egressing the nozzle element; and a polymeric bushing situated within the fuel line interior portion behind the nozzle element, the polymeric bushing comprising a channel or bore extending from end to end and in fluid communication with the nozzle element opening; wherein the polymeric bushing deters and reduces thermal transfer of heat energy through the fuel line, thereby reducing or eliminating accumulation of oil and combustion byproducts on the flame ring stabilizer or air diffuser element, and reducing or eliminating oil pooling within the air tube; a motor in communication with a fan; an ignitor in communication with the combustion head assembly at least one electrode; a controller in communication with the motor and the ignitor; and a fuel line member for the delivery of a fuel to the combustion head assembly.BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The features of the invention believed to be novel, and the elements characteristic of the invention are set forth with particularity in the appended claims. The figures are for illustration purposes only and are not drawn to scale. The invention itself, however, both as to organization and method of operation, may best be understood by reference to the detailed description which follows taken in conjunction with the accompanying drawings in which:

[0025] FIG. 1A depicts a perspective view of a burner according to one embodiment of the invention;

[0026] FIG. 1B depicts an exploded view of the burner of FIG. 1A;

[0027] FIG. 2 depicts a perspective view of a combustion head assembly according to one embodiment of the invention;

[0028] FIG. 3 depicts a perspective view of a portion of the burner according to one embodiment of the invention of the retention head or combustion head assembly with the burner flame retention head (flame ring burner stabilizer) removed;

[0029] FIG. 4 depicts a perspective view of a portion of the burner according to one embodiment of the invention, specifically, the combustion head assembly with the flame ring burner stabilizer (air diffuser) removed, indicating the placement of the polymeric bushing;

[0030] FIG. 5A depicts an image of combustion byproduct buildup on a burner under the conditions of Test #1, utilizing a fuel comprising biodiesel fuel oil, and biodiesel fuel oil blends without the polymeric bushing of the invention, resulting in significant buildup and deposition of combustion byproducts on flame ring burner stabilizer (air diffuser);

[0031] FIG. 5B depicts a disassembled flame ring burner stabilizer of FIG. 5A after going through the Test #1 cycling protocol;

[0032] FIG. 6A depicts the face of the flame ring burner stabilizer under Test #2 cycling protocol;

[0033] FIG. 6B is a close-up view of the face of the flame ring burner stabilizer of FIG. 6A;

[0034] FIG. 6C depicts oil leakage / residue 98 within the air tube of the combustion head assembly after the Test #2 cycling protocol;

[0035] FIGS. 6D and 6E depict oil drops and combustion byproduct on the support leg and backside of the ring of the flame ring burner stabilizer after the Test #2 cycling protocol;

[0036] FIGS. 7A and 7B depict the testing result after the end of the Test #3 cycle protocol, showing a clean flame ring stabilizer surface face; and

[0037] FIG. 7C indicates the absence of any oil pooling in the air tube after running the Test #3 cycle protocol.DETAILED DESCRIPTION OF THE INVENTION

[0038] Embodiments of the present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.

[0039] It will be understood that, although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Also, as used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms “include” and / or “including”, “comprise” and / or “comprising” when used herein, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0040] It will be further understood that when an element is referred to as being “on” or extending “onto” another element, it can be directly on or extend directly onto the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” or extending “directly onto” another element, there are no intervening elements present. It will also be understood that when an element is referred to as being “connected,”“coupled”, “operatively coupled”, or the like to another element, it can be directly connected, coupled, or operatively coupled to the other element or intervening elements may be present. Moreover, it can be removable or integral with the other element and / or intervening elements. In contrast, when an element is referred to as being “directly connected”, “directly coupled”, or “directly operatively coupled” to another element, there are no intervening elements present.

[0041] Relative terms such as “below,”“above,”“upper,”“lower,”“horizontal,”“vertical,”“top,”“bottom,”“rear,”“front,”“side,” or the like may be used herein to describe a relationship of one element or component to another element or component as illustrated in the figures. It will be understood that these terms are intended to encompass different orientations of the device in addition to the orientation depicted in the figures.

[0042] Additionally, in the subject description, the words “exemplary,”“illustrative,” or the like are used to mean serving as an example, instance or illustration. Any aspect or design described herein as “exemplary” or “illustrative” is not necessarily intended to be construed as preferred or advantageous over other aspects or design. Rather, use of the words “exemplary” or “illustrative” is merely intended to present concepts in a concrete fashion.

[0043] In describing the embodiment of the present invention, reference will be made herein to FIGS. 1-7 of the drawings in which like numerals refer to like features of the invention.

[0044] FIGS. 1A and 1B depict perspective and exploded views of a burner 100 according to one embodiment of the invention. Burner 100 comprises a motor 2, for communication with a fan 4 within the burner housing 14. A controller 6 is in electrical communication with an ignitor 12 for the combustion of fuel within the burner, which is delivered via a fuel line member 7. A combustion head assembly or retention ring assembly 30 is disposed extending within an air tube 50 of the outlet 8, attached to burner 14. Outlet 8 is connected to an appliance with a ductwork or piping system for the distribution of heat energy produced by the burner 100 to an apparatus or building interior.

[0045] With additional reference to FIGS. 1B and 2, combustion head assembly 30 includes one or more electrodes 38 in communication with the ignitor 12 for the combustion of fuel fed through the fuel line 32. A nozzle element 36 fits within and engages a nozzle adaptor 33 of the fuel line 32. Nozzle element 36 includes an opening 39, such as a cylindrically shaped bore hole or aperture, in communication with the fuel line interior 31. During a burner cycle, fuel within the fuel line 32 will be carried to the nozzle element opening 39 for the combustion of the fuel via electrode(s) 38. A flame ring burner stabilizer (burner flame retention head) 34 ensures proper mixing of oxygen to ensure the complete combustion of the fuel during a burner cycle.

[0046] Under typical operating conditions, oil in fuel line 32 is under temperature and pressure that will cause the oil to expand and exit nozzle element opening 39.

[0047] The majority of combustion heads in the field today are flame retention heads or flame ring stabilizers or air diffusers. These heads differ from the non-flame retention heads in that the flame is held very close to the face of the head. The flame is smaller and more compact and usually is 300° F. to 500° F. hotter than with non-flame retention heads.

[0048] The flame ring burner stabilizer or air diffuser incorporates three basic elements: (1) a center opening; (2) primary slots; and (3) a secondary opening. The center opening is an orifice in the center of the head which allows clearance for the oil spray and the electrode spark to pass through the head without interfering with the head. The primary slots are slots that radiate out from the center opening towards the outside of the head. The secondary opening is a slot which is concentric to the center opening and follows the circumference of the combustion head. All three openings affect the way air is delivered to the oil spray.

[0049] The primary width regulates the amount and the velocity of the air passing through the slot. This forces the air to move circularly with an axial forward motion. The slots can aid in ensuring the head surface accumulates less fuel burning byproduct. The secondary slot utilizes air pressure to enclose the flame, thus reducing extraneous oil spray. It may also regulate the air necessary to achieve the required firing rate by an adjustment of the slot width.

[0050] FIG. 3 depicts a view of the combustion head assembly with the flame ring burner stabilizer 34 removed. Nozzle 36 is shown attached to nozzle adapter 33.

[0051] FIG. 4 depicts a perspective view of a portion of the burner according to one embodiment of the invention, specifically, the combustion head assembly with the flame ring burner stabilizer 34 (air diffuser) removed. A polymeric bushing 40 is added to this assembly. This can be added to an assembly with no bushing. The substantially cylindrical polymeric bushing 40 comprises a channel or bore hole 42 extending from end to end for the delivery of a fuel to the nozzle element 36. The bushing 40 fits within and engages the fuel line interior 31 in a clearance or transition fit. Bushing 40 comprises a polymeric material having thermal / electrical insulating properties, which will resist degradation, decomposition, dissolution, or breakdown when exposed to No. 2 fuel oil, biodiesel fuel oil, and combinations thereof.

[0052] Exemplary bushing polymeric material may include, but is not limited to, fluoropolymers, such as PTFE (Teflon), which is essentially inert and will not swell or degrade in a petroleum or biofuel environment; fluorinated ethylene propylene (FEP), which is similar to PTFE, and is melt-processable (capable of being heated to a molten state and then formed into a solid object using processes like injection molding, blow molding, or extrusion); perfluoroalkoxy (PFA), which is generally of high purity, inert, and adequate for immersion; ethylene-based fluoropolymers (ETFE / ECTFE), which has adequate resistance to fuels, and is somewhat more robust than PTFE; and polyvinylidene fluoride (PVDF), which has excellent resistance to hydrocarbons and biofuel.

[0053] Other material that may be utilized include a) polyether ether ketones (PEEK), which are chemically resistant to both diesel fuels and biofuels, maintains strength where other fluropolymers can be softened, and reliable for immersion; b) polyphenylene sulfide (PPS), which has very good fuel resistance, handles biofuel well, and achieves good thermal stability; and c) fluoroelastomers (FKM), such as Viton™ brand fluoroelastomers, which are good for seals. Other plastic material may include acrylonitrile butadiene styrene (ABS) plastic, which is a widely used thermoplastic polymer known for its versatility, durability, and ease of processing.

[0054] During a burner cycle, bushing 40 deters and reduces the amount of non-combusted, excess fuel within the fuel line interior 31 under temperature and pressure from exiting nozzle 36. In addition, bushing 40 reduces heat transfer from fuel line interior 31 of fuel line 32. By minimizing the temperate increase following burner cycles and reducing the amount of oil within the nozzle and nozzle adapter, the amount of excess fuel deposits accumulating on the flame ring burner stabilizer 34 is significantly reduced or otherwise diminished, ensuring the proper function of the combustion head assembly 30, and reducing the need for premature service calls. Thus, proper working operations of the burner are ensured, particularly if the fuel comprises biodiesel fuel oil, and biodiesel fuel oil blends.

[0055] The bushing deters and reduces thermal transfer of heat energy from the combustion chamber to the fuel line, which generally causes the accumulation of combustion byproducts on the flame ring stabilizer or air diffuser element. The polymeric bushing facilitates directing and / or preventing a non-combusted fuel in the fuel line interior portion away from the nozzle end after a combustion cycle.

[0056] While bushing 40 comprises a substantially cylindrical polymeric bushing, in alternate embodiments of the invention bushing 40 may include one or a plurality of slots extending within the bushing end or any portion thereof, or forming a peripherally slotted surface. Furthermore, the bushing may include ends having a crenellation-like design, including a plurality of merlons and embrasures on a bushing end to further prevent fuel clogging and facilitating fuel transfer to the side of the fuel line interior 31 proximate fuel line member 7.

[0057] Comparative empirical data has shown that a spacer or bushing fabricated of a polymeric material and situated behind the nozzle can greatly decrease the combustion byproduct buildup on the flame ring burner stabilizer 34. These results were unexpected in comparison to the performance of a burner system without a bushing, and to the performance of a brass bushing situated in a similar location. Performance tests on the impact of carbon build-up over time have shown the unexpected advantages of a polymeric bushing over a standard brass bushing or over the absence of any bushing.Test #1 (No Bushing Incorporated)

[0058] A Bock 32E water heater (standard off-the-shelf EZ-1 burner) was used as a test apparatus operating with pure biofuel (B100). A standard 0.60 60A Delavan® nozzle was inserted into the assembly having an operating supply pressure of 150 psi. No bushing was incorporated in this test run.

[0059] The test apparatus was operated for 51 hours 50 minutes of run time through 634 cycles (cycle time 5 minutes ON / 2 minutes OFF). Next, a water heater T-T closed condition was held. A “water heater T-T closed” message usually means the thermostat is calling for heat (T-T closed), but a limit switch is open, preventing the burner from igniting due to safety concerns like overheating. Under this condition, the water heater burner was operated continuously for over 29 hours. Subsequently, a 34 hour 30 minute run time was performed (cycle time 2 minutes ON / 2 minutes OFF), culminating in a total run time of 115 hours 50 mins through 1690 cycles. The pre-purge cycle was a standard 3 seconds. The Trial-for-Ignition (“TFI”) period was 15 seconds, followed by a 5 second flame stabilizing period. These values represent standard safety features managed by the oil primary control or ignition module that regulate the lighting of the main burner.

[0060] FIG. 5A depicts an image of combustion byproduct buildup on a burner under the aforementioned conditions of Test #1, utilizing a fuel comprising biodiesel fuel oil, and biodiesel fuel oil blends without the polymeric bushing of the invention incorporated into the burner system, resulting in appreciable buildup and deposition of combustion byproducts 90 on flame ring burner stabilizer (air diffuser) 34 after only 116 hours and 1690 cycles. Further combustion byproduct 92 is evident on the circumferential periphery of the flame ring burner stabilizer 34, showing heavy deposits at the 4 o'clock (120° clockwise from the top) and 8 o'clock (120° counterclockwise from the top) positions. A result of the accumulation of combustion byproducts 90, 92 on the flame ring burner stabilizer 34 is known to cause an increase of incomplete combustion, clogging up flue passages within the appliance, and detrimentally affecting efficiency and combustion, as well as the malfunction of the burner, and require more frequent service calls.

[0061] FIG. 5B depicts a disassembled flame ring burner stabilizer 34 after going through the Test #1 cycling protocol. Combustion byproducts 94 are also shown on the underside of the circumferential outer portion of the flame ring burner stabilizer, and on a portion of the support legs 100.Test #2 (Brass Head Bushing Incorporated)

[0062] A Bock 32E water heater (standard off-the-shelf EZ-1 burner) was used as a test apparatus operating with pure biofuel (B100). A standard 0.60 60A Delavan® nozzle was inserted into the assembly having a supply operating pressure of 150 psi. A brass bushing was incorporated in this test run with a 59 mil bore hole (0.059 inches) built therein.

[0063] The test apparatus was operated for 116 hours 16 minutes of run time through 3587 cycles (cycle time 2 minutes ON / 2 minutes OFF). The pre-purge cycle was a standard 3 seconds. The Trial-for-Ignition (“TFI”) period was 15 seconds, followed by a 5 second flame stabilizing period.

[0064] FIG. 6A depicts the face of the flame ring burner stabilizer 34 under Test #2 cycling protocol. After cycling, oil was located in the tube approximately one-half the length down. At the 4 o'clock position, there was visible combustion byproduct 96 on the face of the flame ring stabilizer. Combustion byproduct 98 was also evident on the circumferential periphery of the flame ring burner stabilizer 34, showing heavy deposits at the 4 o'clock (120° clockwise from the top).

[0065] FIG. 6B is a close-up view of the face of the flame ring burner stabilizer of FIG. 6A. As indicated, at the 4 o'clock position, significant combustion byproduct build-up is evident.

[0066] FIG. 6C depicts oil pooling 102 within the air tube of the burner after the Test #2 cycling protocol. FIGS. 6D and 6E depict oil drops and combustion byproduct 104 on the support leg 102 and backside of the ring of the flame ring burner stabilizer after the Test #2 cycling protocol.Test #3 (Polymer Material Bushing Incorporated)

[0067] An embodiment of the invention was evaluated in a similar testing protocol as Tests #1 and #2. A Bock 32E water heater (standard off-the-shelf EZ-1 burner) was again used as a test apparatus operating with pure biofuel (Westmore B100). A standard 0.60 60A Delavan® nozzle was inserted into the assembly having a supply operating pressure of 150 psi. A polymeric bushing (PTFE spacer bushing) was incorporated behind, and was used in this test run, having a 59 mil bore hole (0.059 inches) built therein. It is noted that other polymeric / plastic materials having characteristically similar thermal properties and resistance to degradation under biofuel environments are substitutable for the particular PTFE spacer bushing material and will perform similar functions under these test protocols.

[0068] The Test #3 apparatus was operated for 116 hours 15 minutes of run time through 3585 cycles (cycle time 2 minutes on / 2 minutes off). The pre-purge cycle was a standard 3 seconds. The Trial-for-Ignition (“TFI”) period was 15 seconds, followed by a 5 second stabilizing period.

[0069] There was no evidence of any combustion byproduct on the face of the flame ring stabilizer (air diffuser) 34. This is crucial to maintaining proper air flow and air current through the stabilizer. The absence of any combustion byproduct on the face of the stabilizer is indicative of a cleaner, more efficient operation.

[0070] FIGS. 7A and 7B depict the testing result after the end of the Test #3 cycle protocol, showing a clean flame ring stabilizer surface face. (Carbon build-up 106 is evident at the periphery outside the flame ring stabilizer, but not on the stabilizer face.)

[0071] FIG. 7C indicates the absence of any oil pooling in the air tube 50 after running the Test #3 cycle protocol.

[0072] Furthermore, the backside of the flame ring stabilizer was substantially free from any carbon build-up or combustion byproduct or oil droplets.

[0073] In addition to improved combustion rates of the fuel, it was revealed that the polymeric bushing significantly decreased the accumulation of combustion byproducts on the flame ring stabilizer (air diffuser) 34, allowing consumers to enjoy servicing intervals akin to that of burners utilizing No. 2 fuel oils exclusively.

Claims

1. A combustion head assembly for a burner, comprising:a fuel line having a nozzle end and an interior portion;a nozzle element for coupling engagement with the nozzle end, the nozzle element including an opening;a flame ring stabilizer or air diffuser element proximate the nozzle end and in airflow communication with the burner via an air tube;at least one electrode for the ignition of a fuel egressing the nozzle element; anda polymeric bushing situated within the fuel line interior portion behind said nozzle element, the polymeric bushing comprising a channel or bore extending from end to end and in fluid communication with said nozzle element opening;wherein said polymeric bushing deters and reduces thermal transfer of heat energy through the fuel line, thereby reducing or eliminating accumulation of oil and combustion byproducts on said flame ring stabilizer and / or air diffuser element, and / or reducing or eliminating oil pooling within said air tube.

2. The combustion head assembly of claim 1, wherein the polymeric bushing directs away and / or prevents an un-combusted fuel in the fuel line interior portion from the nozzle end after a combustion cycle.

3. The combustion head assembly of claim 1 wherein said polymeric bushing comprises a polymeric material having thermal / electrical insulating properties, which is resistant to decomposition, dissolution, or breakdown when exposed to No. 2 fuel oil, biodiesel fuel oil, and / or combinations thereof.

4. The combustion head assembly of claim 1 wherein said polymeric bushing comprises fluoropolymers, including PTFE (Teflon), fluorinated ethylene propylene (FEP), perfluoroalkoxy (PFA), ethylene-based fluoropolymers (ETFE / ECTFE), and / or polyvinylidene fluoride (PVDF).

5. The combustion head assembly of claim 1 wherein said polymeric bushing comprises polyether ether ketones (PEEK), polyphenylene sulfide (PPS), and / or fluoroelastomers (FKM).

6. The combustion head assembly of claim 1 wherein said polymeric bushing comprises acrylonitrile butadiene styrene (ABS).

7. The combustion head assembly of claim 1 wherein said combustion head assembly is incorporated within a burner system, wherein said burner system comprises:a burner housing including an air tube and an outlet;said combustion head assembly disposed within the burner air tube;a motor in communication with a fan;an ignitor in communication with the combustion head assembly at least one electrode;a controller in communication with the motor and the ignitor; anda fuel line member for the delivery of a fuel to the combustion head assembly.

8. The combustion head assembly of claim 1 wherein said polymeric bushing fits within and engages the fuel line interior portion in a clearance or transition fit.

9. The combustion head assembly of claim 1 wherein said polymeric bushing includes one or a plurality of slots extending within an end of said polymeric bushing or any portion thereof.

10. The combustion head assembly of claim 9 wherein said plurality of slots forms a peripherally slotted surface of said polymeric bushing.

11. The combustion head assembly of claim 1 wherein said polymeric bushing includes an end having a crenellation-like design, including a plurality of merlons and embrasures to further prevent fuel clogging and facilitating fuel transfer to a side of the fuel line.

12. A burner system comprising:a burner housing including an air tube and an outlet;a combustion head assembly disposed within the burner air tube, said combustion head assembly including:a fuel line having a nozzle end and an interior portion;a nozzle element for coupling engagement with the nozzle end, the nozzle element including an opening;a flame ring stabilizer or air diffuser element proximate the nozzle end and in airflow communication with said air tube;at least one electrode for the ignition of a fuel egressing the nozzle element; anda polymeric bushing situated within the fuel line interior portion behind said nozzle element, the polymeric bushing comprising a channel or bore extending from end to end and in fluid communication with said nozzle element opening;wherein said polymeric bushing deters and reduces thermal transfer of heat energy through the fuel line, thereby reducing or eliminating accumulation of oil and combustion byproducts on said flame ring stabilizer or air diffuser element, and reducing or eliminating oil pooling within said air tube;a motor in communication with a fan;an ignitor in communication with the combustion head assembly at least one electrode;a controller in communication with the motor and the ignitor; anda fuel line member for the delivery of the fuel to the combustion head assembly.

13. The burner system of claim 12 wherein said polymeric bushing comprises a polymeric material having thermal / electrical insulating properties, which is resistant to decomposition, dissolution, or breakdown when exposed to No. 2 fuel oil, biodiesel fuel oil, and / or combinations thereof.

14. The burner system of claim 12 wherein said polymeric bushing comprises fluoropolymers, including PTFE (Teflon), fluorinated ethylene propylene (FEP), perfluoroalkoxy (PFA), ethylene-based fluoropolymers (ETFE / ECTFE), and / or polyvinylidene fluoride (PVDF).

15. The burner system of claim 12 wherein said polymeric bushing comprises polyether ether ketones (PEEK), polyphenylene sulfide (PPS), and / or fluoroelastomers (FKM).

16. The burner system of claim 12 wherein said polymeric bushing comprises acrylonitrile butadiene styrene (ABS).

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