All gas burners are susceptible to lint, dust or oil (LDO) accumulation in harsh environments. These gas burners must shut down before exceeding carbon monoxide (CO) limits. When there is an accumulation of lint, dust or oil, this can cause the gas burner flame to flatten out and increase the internal temperature of the gas appliance's combustion chamber. Therefore, it is desired to have a pilot burner that will shut down when there is an excessive amount of lint, dust or oil. An illustrative, but nonlimiting example, of a gas appliance that utilizes a gas burner is a water heater. Moreover, it is desirable to have a low NOx pilot burner. This is due to the fact that NOx is the generic term for a group of highly reactive gases, all of which contain nitrogen and oxygen in varying amounts.
There are now standards that dictate that a water heater must not produce flue gases that contain carbon monoxide in excess of 0.04 (%) percent on an air free basis when exposed to lint, dust or oil. These test standards are listed under ANSI Z21.10.1b-2004, CSA 4.1b-2004, Section 2.36 as “Resistance to Lint, Dust and Oil Accumulation.” This is also mandated by regulation such as the South Coast Air Quality Management District's Rule 1121 for “Control of Nitrogen Oxides from Residential Type, Natural Gas-Fired Water Heaters.” This Rule dictates the NOx emission level per joule of heat output.
The present invention is directed to overcoming one or more of the problems set forth above.
An aspect of the present invention is a pilot burner assembly. The pilot burner assembly includes a pilot burner having a top portion, middle portion and a bottom portion, wherein the top portion of the pilot burner includes a hood that is positioned adjacent to an igniter and a thermocouple. A middle portion of the pilot burner includes at least one opening providing an air inlet.
Another aspect of the present invention may optionally include a bracket assembly. The bracket assembly may be operatively attached to a pilot burner, a thermocouple assembly and an igniter assembly. Preferably, but not necessarily, a pilot burner is mounted at an angle with the thermocouple located lower than the pilot burner hood, e.g., 60°+/−15° in relationship to the bracket assembly. The bracket assembly may include a vertical portion with attachment holes as well as a u-shaped bracket with an upper opening and a lower opening for receiving a thermocouple. Optionally, the bracket assembly may include a first top plate and a second top plate connected together.
Still another aspect of the present invention may optionally include a hood. The hood may have at least one opening and preferably includes more than one opening to form a multiple-way hood, e.g., two-way hood. The at least one opening can include a wide variety of geometric shapes and sizes but is preferably triangular with an opening that can provide flame direction and pattern as well as a spark path between an igniter and a pilot burner.
Yet another aspect of the present invention may optionally include an insert. The insert may include an upper portion, a middle portion and a lower portion. Optionally, the middle portion can include a flange can be positioned on top of a bracket assembly and the lower portion can be threaded. The presence of lint, dust and/or oil will restrict at least one opening, e.g., four (4), created by a hole(s) or slot(s) forming at least one primary air intake orifice. A primary air intake orifice is located in the middle portion of the insert that extends from an inner chamber of the insert to an outer surface of the middle portion of the insert.
In still another aspect of the present invention may optionally include an orifice spud. The orifice spud controls the primary flow of gas in the pilot burner and restricts the flow of gas. The orifice spud may include a first sidewall, a second sidewall and a nozzle. The nozzle may include an opening. The opening may include a first slot and a second slot that are positioned transverse, e.g., perpendicular, to each other and in fluid communication.
Another aspect of the present invention may optionally include a ball sleeve. The ball sleeve may provide a compression seal between an orifice spud and a compression nut. Optionally, the ball sleeve may include a triangular portion.
Still another aspect of the present invention may optionally include a compression nut. The compression nut may provide connection to a gas valve and operate to compress a ball sleeve. The compression nut may be threadedly attached to a threaded end portion for an insert.
It is another aspect of the present invention includes an igniter. The igniter may include a protruding electrode that can be bent to extend adjacent to an opening in a hood. There may be an insulator that can secure the electrode. An illustrative, but nonlimiting insulator can include ceramic material. The electrode is preferably at least partially covered in an insulating material. The insulator may be secured in the bracket assembly with an upper ring and a combination electrode holder and retainer.
Yet another aspect of the present invention is a method of utilizing a pilot burner assembly. The method includes positioning a pilot burner, having a top portion, a middle portion and a bottom portion, near a thermocouple and an igniter so that when at least one opening providing an air inlet in the middle portion of the pilot burner is at least partially blocked with lint, oil or dust, then the flame to heat the thermocouple will shrink or lift to the point where it no longer can heat the thermocouple sufficiently to generate enough power to allow for a safety magnet valve to remain energized and will shut-off the associated gas-fired device.
These and other features and advantages of the present invention will become apparent from the following detailed description of a preferred embodiment which, taken in conjunction with the accompanying drawings, illustrates by way of example the principles of the present invention.
For a better understanding of the present invention, reference may be made to the accompanying drawings in which:
While the various features of this invention are hereinafter illustrated and described as being particularly adapted to provide a pilot burner construction for burning gaseous fuel, such as natural or synthetic gas, it is to be understood that the various features of this invention can be utilized singly or in various combinations thereof to provide a pilot burner construction for other types of apparatus as desired. A typical pilot burner is disclosed in U.S. Pat. No. 5,039,300, which issued to Riehl on Aug. 13, 1991, which is incorporated herein by reference. Another example of a pilot burner is disclosed in U.S. Patent Application No. 20030183177, published on Oct. 2, 2003 to Kobayashi et al, which is incorporated herein by reference as well as U.S. Patent Application No. 20010003274, published on Jun. 14, 2001, which is incorporated herein by reference.
Therefore, this invention is not to be limited to only the embodiment illustrated in the drawings because the drawings are merely utilized to illustrate one of the wide variety of uses of this invention. The valve of the present invention is especially suited for controlling the flow of a combustible gas to a gas-fired appliance such as a furnace, a water heater or a gas-burning fireplace.
As shown in
During situations where LDO (lint-dust-oil) build-up has occurred, the hood 12 will continue to provide flame to the main burner 2, but the flame to heat the thermocouple 20 will shrink or lift to the point where it no longer can heat the thermocouple 20 sufficiently to generate enough power to allow for the safety magnet valve (not shown) to remain energized. This will result in an associated gas-fired device shutting off. The thermocouple 20 is essentially a sensor that is utilized in a gas-fired device for detecting heat from the pilot burner 10. There is an igniter 22 for providing a spark to ignite the pilot burner 10 that is located adjacent to the hood 12 of the pilot burner 10.
Referring now to
There is also the pilot burner 10 that includes the hood 12 that is mounted on top of the bracket assembly 100 with extending flange members 101, e.g., four (4). There are holes or slots 112 creating primary air intake orifices located underneath the hood 12 and just above the bracket assembly 100. However, these holes or slots 112 are not limited to being positioned just above the bracket 100 and can be located along the length of the pilot burner 10 both above and below the bracket 100.
Referring now to
Referring now to
Referring now to
Positioned within the burner 10 is an orifice spud 220, as shown in
There is a ball sleeve 222 to provide a compression seal between the orifice spud 220 and a compression nut 224, as shown in
As shown in
Referring now to
A method of utilizing a pilot burner 10 is also contemplated with an embodiment of the invention. The method includes positioning a pilot burner 10 near a thermocouple 20 and an igniter 22 so that when at least one primary air intake orifice 112 to the pilot burner 10 is at least partially blocked with lint, oil or dust, then the flame to heat the thermocouple 20 will shrink or lift to the point where the pilot burner can no longer can heat the thermocouple 20 sufficiently to generate enough power to allow for a safety magnet valve (not shown) to remain energized and will shut the associated gas-fired device such as the main gas burner 2.
While a particular form of the invention has been illustrated and described, it will also be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention. Accordingly, it is not intended that the invention be limited except by the appended claims.
This application is related to and claims priority from U.S. provisional patent application Ser. No. 60/593,776 filed Feb. 11, 2005, having inventor Frederick D. Lyles, entitled “Low NOx Pilot Burner And Associated Method Of Use.”
Number | Date | Country | |
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60593776 | Feb 2005 | US |