Single-stage gas valve

Abstract

A combustion assembly includes a single stage gas valve, a burner member having a flame end, a spark generating member, a flame sensing member, and a controller. The spark generating member generates a spark in response to a spark signal and is positioned adjacent to the flame end of the burner member. The flame sensing member senses the presence of a flame and is also positioned adjacent to the flame end. The controller provides a valve open signal to the valve to control a flow of gas to the burner member, provides a spark signal to the spark generating member to generate a spark that ignites the flow of gas, receives a flame sense signal from the flame sensing member related to the state of the flame, and provides a valve closed signal to stop the flow of gas when the flame sense signal indicates no flame is present.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to gas valves and burner assemblies, and more specifically relates to a single stage gas valve that is regulated based on flame conditions at the burner assembly.

2. Related Art

Gas burners are used in a variety of applications including, for example, fireplaces, boilers, hot water heaters, furnaces, gas grills, cooking stoves and ovens, lanterns, etc. In each application, the gas burner must meet specifications related to, for example, available power, efficiency ratings, safety, etc. that are often unique to that application. Most gas burners are used in combination with an ignition system and a gas valve that controls the flow of gas fuel to the burner for ignition into a flame by the ignition system.

One important safety concern related to gas burners is the inadvertent release of unburned gas via the burner. This situation may occur if, for example, the ignition system fails to properly ignite the flame and the gas valve remains open, resulting in the release of gas through the burner. If the ignition then engages, that can cause dangerous ignition of the gas. This is sometimes called delayed ignition. Some ignition systems and related burner control systems include sensors that monitor a flame condition at the burner to ensure that a flame is present within a predetermined time period of the gas valve being open and the ignition system generating a spark to ignite a flame.

Other systems include a pilot light that provides a constant spark/flame at the burner to ensure that any gas flow that is provided to the burner will result in the generation of a flame that burns the gas flow. The addition of a pilot light can add additional cost, complexity, and inefficiency to a gas burner and its related gas valve, ignition and control systems.

Gas burner systems used with light fixtures such as gas lanterns have historically been at least partially manually operable. In one configuration, such manual systems include a manual valve that must be turned on and off, and a separate igniter that must be activated to ignite the gas into a flame. In other configurations, the igniter, gas valve, or other features may at least partially automatically function. However, no known configurations provide automated features that provide both safety and efficiency required to meet some types of certifications, such as CSA certificates of compliance. As a Nationally Recognized Testing Laboratory (NRTL) accredited by OSHA, CSA International can test and certify products following standardized test protocols in laboratories across the United States. CSA International tests to applicable U.S. standards, including ANSI, UL, CSA, NSF, and many others.

A gas burner that can operate without a pilot light while addressing the safety and efficiency issues noted above would be an advance in the art.

SUMMARY OF THE INVENTION

The present invention relates to gas valves and burner assemblies that are functional without the use of a pilot light. One objective of the present invention is to provide a gas valve, wherein an electromagnetic valve is used to control the output of gas to a gas burner. The electromagnetic valve is regulated based on sensor feedback at the gas burner. The electromagnetic valve is closed if a flame is not sensed at the burner when the flame is intended to be present, and maintains an open position if the flame is sensed when intended to be present.

One aspect of the invention relates to a combustion assembly that includes a single stage gas valve, a burner member having a flame end, a spark generating member, a flame sensing member, and a controller. The spark generating member generates a spark in response to a spark signal and is positioned adjacent to the flame end of the burner member. The flame sensing member senses the presence of a flame and is also positioned adjacent to the flame end. The controller provides a valve open signal to the valve to control a flow of gas to the burner member, provides a spark signal to the spark generating member to generate a spark that ignites the flow of gas, receives a flame sense signal from the flame sensing member related to the state of the flame, and provides a valve closed signal to stop the flow of gas when the flame sense signal indicates no flame is present.

Another aspect of the invention relates to a gas burner assembly that includes a single stage gas valve, a burner device, a flame sense device, and an ignition device. The burner device of the combination includes a gas outlet at a flame end of the burner device and is configured to generate a flame that extends from the flame end. The gas valve of the combination is a single stage gas valve that is movable between a closed position wherein no gas flow is provided to the burner device and an open position wherein a gas flow is provided to the gas outlet of the burner device. The flame sense device of the combination is positioned adjacent to the flame end of the burner device and is configured to provide a flame signal indicative of the presence of the flame. The ignition device of the combination is also positioned adjacent to the flame end of the burner device and is configured to provide a spark when the gas valve is open, the spark igniting the flow of gas out of the gas outlet of the burner device to generate the flame. The gas valve closes when the flame signal indicates that no flame is present.

A further aspect of the invention relates to a method of generating and monitoring a flame with a combustion assembly, the combustion assembly including a gas valve, a burner device, an ignition system, and a flame sense member. The gas valve includes a regulator member that controls the flow of gas out of the gas valve. The burner device includes a gas outlet at a flame end of the burner device. The method includes opening the gas valve with the regulator to provide a flow of gas from the gas valve to the gas outlet of the burner device, generating a spark with the ignition system for igniting the flow of gas into a flame at the flame end of the burner device, sensing the state of the flame with the flame sense member, and closing the gas valve when the presence of the flame is not sensed by the flame sense member.

A still further aspect of the invention relates to a lantern single stage gas valve and burner assembly that includes a valve housing, a moveable plate, a mangnetoresistive member, a power source, and a burner assembly. The valve housing includes a gas inlet and a gas outlet and the moveable plate is positioned between the gas inlet and the gas outlet to control gas flow through the valve housing. The magnetoresistive member is configured to move the moveable plate upon activation by a power input. The power source provides the power input in the range of about 1 to 6 volts DC. The burner assembly is coupled to the housing and configured to produce a flame. The magnetoresistive member automatically moves the moveable plate to stop gas flow when no flame is present at the burner assembly.

The above summary of the present invention is not intended to describe each disclosed embodiment or every implementation of the present invention. The Figures and the detailed description that follow more particularly exemplify certain embodiments of the invention. While certain embodiments will be illustrated and describe embodiments of the invention, the invention is not limited to use in such embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which:

FIG. 1 is a perspective view of an assembly in a possible embodiment of the present invention;

FIG. 2 is an exploded perspective view of the assembly of FIG. 1;

FIG. 3 is a front view of the assembly of FIG. 1;

FIG. 4 is a side view of the assembly of FIG. 1;

FIG. 5 is a top view of the assembly of FIG. 1;

FIG. 6 is a cross-sectional view of the assembly shown in FIG. 5 taken along cross-sectional indicators 6-6;

FIG. 7 is a schematic circuit diagram for the assembly of FIG. 1;

FIG. 8 is an example gas lantern that includes the assembly of FIG. 1;

FIG. 9 is a cross-sectional view of the gas lantern shown in FIG. 8; and

FIG. 10 is a flow diagram illustrating steps of an example method of using the assembly shown in FIG. 1.

While the invention is amenable to various modifications and alternate forms, specifics thereof have been shown by way of example and the drawings, and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention generally relates to gas valve and burner assemblies and related sensing, ignition, and control systems. More specifically, the present invention relates to a combustion system or assembly that includes a single stage valve, a burner member having a flame end, a spark generating member, a flame sensing member, and a controller. The controller sends and receives signals related to the flow of gas from the gas valve to the burner member, the generation of a spark to ignite a flame at the flame end of the burner member, and a sensed state of the flame provided by the flame sensing member. This example configuration provides generation and monitoring of a flame without the use of a pilot flame or pilot valve, thus reducing the complexity and cost of the combustion system as compared to some known combustion systems. In some embodiments, this example configuration is operable using solely a DC power input, making it possible to operate the system use a low voltage battery pack rather than an AC power input.

As used herein, the terms “combustion system” and “combustion assembly” relate to a system or device that is configured to combust a combustible material such as natural gas or liquid propane in a controller manner. A “controller” as used herein may be any control device such as a microprocessor or assembly of circuit components that sends and receives signals. A “single stage valve” is defined as a valve having valve components that controls a single input and output flow of fluid through the valve.

Referring now to FIGS. 1-6, an example combustion assembly 10 is shown and described. Assembly 10 includes a single stage valve 12, a burner member 14, an ignition member 16, a flame sense member 18, a mounting bracket 20, a gas conduit 22, and a controller 24. The controller 24 controls the generation of a flame at the burner 14 in response to an open or closed position of the valve 12, sparks generated by the ignition member 16, and a state of the flame determined by the flame sense member 18.

The single stage valve 12 includes a base 30, a cover 32, a seal 34, a regulator 36, an electromagnetic member 50, a movable valve plate 52, a conduit 54, a shield 56, and a valve connector cable 58. The base 30 includes an inlet collar 40, an outlet collar 42, an inlet channel 44, and an outlet channel 46. The regulator 36 controls a position of the moveable valve plate 52 in response to open and close valve signals from the controller 24. The regulator 36 applies an electric charge to the electromagnetic member 50 that creates an axial force, which when applied to the plate 52 can move the plate 52 relative to an opening 55 into the conduit 54. The shield 56 provides both physical and electrical shielding of the plate 52 to ensure that the plate maintains the open or closed position. When the plate 52 is in the open position relative to opening 55, gas flows through the inlet channel 44, through the opening 55 into the conduit 54, and through the outlet channel 46 into the gas conduit 22 for combustion at the burner member 14.

While the valve 12 is well suited for providing precise control of fluid flow through the valve in response to an incoming signal from the controller 24, other valve embodiments may be used. For example, a magnetic motor, a stepper motor, or a linear actuator could be used to control gas flow to the burner member 14.

The burner member 14 includes a flame opening 60 at a flame end 61, and a grounding member 62 having an end tip 64. The burner member 14 has a generally elongate body with a conduit 65 extending along the length of the burner member 14 (see FIG. 6). The conduit 65 is oriented substantially coaxially with the gas conduit 22 and the inlet and outlet collars 40, 42 of the valve 12. As a result, the combustion assembly 10 has a generally elongate configuration, which makes it possible for the combustion assembly 10 to fit within an elongate structure such as, for example, a cylinder having a diameter no smaller than a maximum width W (see FIG. 3) of the combustion assembly 10. One application for a combustion assembly having the elongate construction shown in FIGS. 1-6 is useful with a gas lantern, wherein the combustion assembly 10 is positioned within a cylindrical post that supports the lamp. An example lamp assembly is shown and described in U.S. patent application Ser. No. 10/803,535 filed on Mar. 17, 2004, and entitled Gas Light Systems and Methods of Operation, which application is incorporated herein by reference.

The ignition member 16 includes a sparking tip 70 and a connector cable 72. The ignition member 16 is structured and mounted to the mounting bracket 20 at a position so as to orient the spark tip 70 at a preferred distance from the flame opening 60 of the burner member 14. Due to the spacing between the spark tip 70 and the flame end 61 of the burner member 14 that is preferred for minimizing obstruction of the flame, the ignition member 16 may have difficulty generating a spark when using the flame end 61 as an electrical ground member. Typically, the burner member 14 provides the ground through which the spark tip 70 creates a spark. To reduce the distance between the grounding member and the spark tip 70, the grounding member 62 has been added to the burner member 14. The grounding member 62 may include a pointed end tip 64 that provides minimal interruption of the flame shape while still providing the desired grounding function. In some embodiments, grounding can be provided with a two-wire system that sends power and ground to the desired sight using two or more conductors. In some embodiments, the ignition member may function via a thermocouple-voltage response or via a thermopile-voltage generation.

The flame sense member 18 includes a sensor tip 80 and a conductor cable 82. The flame sense member 18 is also mounted to the bracket 20 and is shaped so as to position the sensor tip 80 at a desired distance from the flame end 61 of the burner member 14. The flame generated by the burner member 14 is an ionized flame and requires grounding in order for the flame sense member 18 to determine whether the flame is in existence. Therefore, the grounding member 62 has been included as an extension of the burner member 14 to provide a grounding member in contact with the flame so as to activate sensing of the flame by the flame sense member 18.

Both the spark tip 70 and sensor tip 80 are sized and positioned relative to the flame end 61 of the burner member 14 so as to provide minimal disruption of the flame generated by the burner member. This minimized obstruction of the flame is especially important when the combustion assembly 10 is used solely for generating light in a lantern application. In other applications, obstruction or disruption of the flame may be less important.

Referring now to FIG. 2, the bracket 20 may include first and second members 90, 92. The members 90, 92 are configured for mounting the valve 12 relative to the burner member 14, ignition member 16, and flame sense member 18, and for mounting the bracket 20 to a mounting surface to which the combustion assembly 10 is secured. In other embodiments, different bracket configurations or additional bracket members may be used for mounting various features of the assembly 10.

The valve 12, burner member 14, ignition member 16, flame sense member 18, and controller 24 are operable using a relatively low power input, and may function using a DC voltage input. A system that requires only DC power makes it possible to operate the system using a battery pack (e.g., battery pack 25 shown in FIG. 1) rather than an AC power source. A system that can operate using DC battery power may be particularly useful with a gas lantern, wherein the gas lantern can be positioned at any location around a living structure or yard without the need for an AC power connection. Positioning of such a gas lantern may be further unrestricted if the gas lantern uses a portable fuel source, such as described in U.S. patent application Ser. No. 10/803,535. Other embodiments may be configured for using AC power or may include a converter or other capabilities that permit the system to function using either AC or DC power.

The controller may be a separate controller that is positioned remotely from the valve 12, burner 14, ignition member 16, and flame sense member 18 as shown in FIGS. 1, 4 and 5. However, other embodiments may include the controller mounted directly to the valve (e.g., adjacent to the regulator 36 on the cover 32 of the valve), or to the mounting bracket 20 or other space interposed between various features of the combustion assembly 10. Example devices for use as the controller include a micro-based controller and a series of amplifying transistors.

FIGS. 8 and 9 illustrate an example gas lantern 100 that includes the example combustion assembly 10. Some portions of the assembly 10 (e.g., the valve 12) may be positioned within a cylindrical post 102 of the lantern 100 while other portions of the assembly 10 (e.g., the burner member 14, the ignition member 16, and the flame sense member 16) may be positioned within a light housing 104 of the lantern 100. The lantern 100 includes an on/off switch 106 that is coupled to the controller 24 of the combustion assembly 10.

Referring now to FIG. 7, a schematic circuit diagram representing the control functions of the combustion assembly 10 is shown. The specific values for the various components can vary depending on the system requirements. Further, the schematic of FIG. 7 is only one of many configurations possible for providing the desired control of the combustion assembly 10. The diagram shown in FIG. 7 functions generally to provide the method steps described with reference to FIG. 10 given the inputs and outputs shown.

According to a first step of the example method shown in FIG. 9, a gas valve is opened with a regulator to provide a flow of gas from the gas valve to the gas outlet for the burner device. As discussed above, the regulator of the gas valve is controlled by an open valve control signal provided by the controller. In some embodiments, the open valve control signal may come directly from a user input such as, for example, by a manual activation of the valve into an open position. As noted above, the gas valve may include an electromagnetic member, a moveable valve plate, and a plurality of conduits and openings that provide for gas flow through the gas valve and to the outlet of the burner device for combustion into a flame.

Another method step includes generating a spark within an ignition system for igniting the flow of gas into a flame at a flame end of the burner device. The ignition system may generate a spark between a spark tip of an ignition member of the ignition system and a grounding member that extends from the flame end of the burner member.

Another method step includes sensing the state of the flame with a flame sensing member. The flame sensing member may include a sensor tip that is spaced apart from a flame end of the burner member. The grounding member that extends from the flame end of the burner member may provide the necessary grounding required for the ionized flame to be sensed by the sensor tip of the flame sensing member. In the event that a flame has not been ignited after the gas valve has been opened and a spark has been generated, the flame sensing member will provide a flame sense signal that indicates that a flame is not present. In response to such a flame sense signal, the gas valve is automatically closed.

In all of the above-described steps, the controller may be used to send and receive the various signals related to opening and closing of the gas valve, generating a spark, and sensing the state of the flame. The controller may also be used to generate the sequence of events related to the method steps. The controller may also be used to interpose predetermined time periods in between the various method steps. For example, after the controller sends a valve open signal to open the valve, the controller may wait a predetermined time period (e.g., about 1 to 2 seconds) before sending a spark signal to the ignition system for generating a spark. After sending the spark signal, the controller may wait another predetermined time period before activating the sensing member at which time the sensing member senses the state of the flame. If a controller does not immediately receive a sensing signal from the flame sense member that a flame exists, the controller may again activate the flame sense member to sense for the state of the flame, or may first send another spark signal to the ignition system for generation of a spark prior to activating the sensing member again. The controller may also wait a predetermined time period between the time at which the controller determines that a flame is not in existence and when the gas valve is closed, although it is preferable for the gas valve to be closed immediately upon the controller determining that the flame is not in existence.

According to the above description, the system can be fully automated during the process of igniting the flame once activated (typically by a user) to start the ignition sequence) and ensuring that the flame is present when intended to be present. This automated system provides a relatively high level of safety for the system with respect to minimizing the occurrence of an inadvertent release of unburned gas from the burner. Furthermore, this automated system makes it possible to generate a controlled flame without the need for a pilot light, thus increasing the fuel efficiency and minimizing the complexity and cost of the system.

The present invention should not be considered limited to the particular examples or materials described above, but rather should be understood to cover all aspects of the invention as fairly set out in the attached claims. Various modifications, equivalent processes, as well as numerous structures to which the present invention may be applicable will be readily apparent to those of skill in the art to which the present invention is directed upon review of the instant specification.

Claims

1. A combustion assembly, comprising:

a single stage gas valve;

a burner member having a flame end;

a spark generating member configured to generate a spark in response to a spark signal, the spark generating member being positioned adjacent to the flame end of the burner member;

a flame sensing member configured to sense the presence of a flame, the flame sensing member being positioned adjacent to the flame end of the burner member; and

a controller configured to control the valve, spark generating member, and flame sensing member for the generation of a flame at the flame end of the burner member.

2. The assembly of claim 1, further comprising a grounding member extending from the flame end of the burner assembly, the grounding member providing a grounding function for the generation of a spark by the spark generating member and a grounding function for the flame sensing member.

3. The assembly of claim 2, wherein the controller is configured to provide a valve open signal to the single stage valve to provide a flow of gas to the burner member, to provide a spark signal to the spark generating member generates a spark to ignite the flow of gas, to receive a flame sense signal from the flame sensing member related to the state of the flame, and to provide a valve closed signal to stop the flow of gas when the flame sense signal indicates no flame is present.

4. The assembly of claim 1, wherein the single stage valve includes a regulator, the regulator including a magnetic member and a moveable valve member, the magnetic member being configured to move the moveable valve member between opened and closed positions in respond to a change in polarization of the magnetic member.

5. The assembly of claim 1, wherein the gas valve includes an electromagnetic member, a gas conduit, and a moveable plate moveable in response to magnetic forces provided by the electromagnetic member to open or close the gas conduit to provide the flow of gas.

6. The assembly of claim 1, wherein the vent assembly does not include a pilot valve or a pilot flame.

7. A gas burner assembly, comprising:

a burner device having a gas outlet at a flame end of the burner device, the burner device being configured to generate a flame that extends from the flame end;

a single stage gas valve including a single valve member movable between a closed position obstructing a gas flow path through the valve wherein no gas flow is provided to the burner device and an open position removed from the gas path wherein a gas flow is provided to the gas outlet of the burner device;

a flame sensing device positioned adjacent to the flame end of the burner device and configured to provide a flame signal indicative of the presence of the flame; and

an ignition device positioned adjacent to the flame end of the burner device and configured to provide a spark when the gas valve is open, the spark igniting the flow of gas out of the gas outlet of the burner device to generate the flame;

wherein the gas valve automatically moves to the closed position when the flame signal indicates that no flame is present.

8. The gas burner assembly of claim 7, further comprising a grounding member extending from the flame end of the burner assembly, wherein the grounding member provides a grounding function for the generation of a spark by the ignition device and provides a grounding function for the flame sensing device.

9. The gas burner assembly of claim 7, wherein the burner has an elongate structure and defines a conduit that extends along a length of the burner, and an axis of the conduit is aligned in a vertical orientation in alignment with an outlet conduit of the gas valve.

10. A gas lantern, comprising:

a support stand;

a lamp housing supported by the support stand; and

the gas burner assembly of claim 7 positioned at least partially within the support stand and the lamp housing.

11. A method of generating and monitoring a flame with a combustion assembly, the combustion assembly including a gas valve, a burner device, an ignition system, and a flame sense member, the gas valve including a regulator member that control the flow of gas out of the gas valve, the burner device including a gas outlet at a flame end of the burner device, the method comprising the steps of:

opening the gas valve with the regulator to provide a flow of gas from the gas valve to the gas outlet of the burner device;

generating a spark with the ignition system for igniting the flow of gas into a flame at the flame end of the burner device, the flame providing light generated by the combustion assembly;

sensing the state of the flame with the flame sense member; and

closing the gas valve when the presence of the flame is not sensed by the flame sense member.

12. The method of claim 11, coupling a grounding member to the burner device at the flame end, the grounding member extending into a path of the flame, wherein the grounding member provides grounding for generation of a spark by the ignition system and grounding for the flame sense member.

13. The method of claim 1 1, further comprising repeating the opening, generating and sensing steps after the closing step until a flame is sensed by the flame sense device.

14. The method of claim 11, wherein the combination further includes a controller, wherein the controller provides a valve signal for opening and closing the gas valve, provides an ignition signal for control of the ignition system, and receives flame signals from the flame sense member related to the state of the flame.

15. The method of claim 1 1, further comprising waiting a first predetermined time period between the opening and generating steps and a second predetermined time period between the generating and sensing steps.

16. The method of claim 1 1, wherein after the flame sense member senses that no flame is present, repeating the generating and sensing steps before the closing step.

17. A lantern single stage gas valve and burner assembly, comprising:

a valve housing having a gas inlet and a gas outlet;

a moveable plate positioned between the gas inlet and the gas outlet to control gas flow through the valve housing;

a magnetoresistive member configured to move the moveable plate upon activation by a power input;

a power source that provides the power input in the range of about 1 to 6 volts DC;

a burner assembly coupled to the housing and configured to produce a flame;

wherein the magnetoresistive member automatically moves the moveable plate to stop gas flow when no flame is present at the burner assembly.

18. The assembly of claim 17, wherein the power input is about 3 volts DC.

19. The assembly of claim 17, wherein the power input is provided in the form of AC or DC power.