Burner System And A Method Of Control

Abstract

A burner system and a method of control. The system includes a supply unit that provides a gas/air mixture to a burner assembly. The burner assembly includes a distribution outlet having a plurality of openings and an electrode. The electrode provides an electrical arc to ignite the gas/air mixture for a predetermined period of time.

Description

BACKGROUND

[0001] 1. Technical Field

[0002] The present invention relates to a burner system and a method of control.

[0003] 2. Background Art

[0004] An example of a flame torch is disclosed in U.S. Pat. No. 7,371,992.

SUMMARY

[0005] In at least one embodiment a burner system is provided. The burner system includes a burner assembly that has a distribution outlet having a plurality of openings and an electrode spaced apart from the distribution outlet. The supply unit is configured to provide a gas/air mixture to the burner assembly via a hose. The electrode provides an electrical arc to ignite the gas/air mixture for a predetermined period of time.

[0006] In at least one embodiment a method of controlling a burner system is provided. The method includes providing a gas/air mixture to a burner assembly, energizing an electrode, determining whether the gas/air mixture ignites within a predetermined period of time, determining whether a fault is detected, and providing a warning signal if a fault is detected.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 is a perspective view of an embodiment of a burner system having a burner assembly and a supply unit.

[0008] FIG. 2 is a fragmentary side view of the supply unit.

[0009] FIG. 3 is a perspective view of the burner assembly.

[0010] FIG. 4 is a perspective view of another embodiment of a burner system.

[0011] FIG. 5 is a flowchart of a method of control of the burner system.

DETAILED DESCRIPTION

[0012] Detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale, some features may be exaggerated or minimized to show details of particular components. In addition, any or all features from one embodiment may be combined with any other embodiment. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for the claims and/or as a representative basis for teaching one skilled in the art to variously employ the present invention.

[0013] Referring to FIG. 1, an embodiment of a burner system 10 is shown. The system 10 may be used to flame treat and/or remove excess material or flashing from a workpiece 12, such as a molded workpiece made of one or more polymeric materials like a thermoplastic olefin (TPO).

[0014] The system 10 may include a supply unit 14 and a burner assembly 16.

[0015] Referring to FIGS. 1 and 2, the supply unit 14 may include a mixture subsystem 20 and a control subsystem 22. The control subsystem 22 may monitor and/or control operation of the system 10.

[0016] The mixture subsystem 20 may be configured to receive, mix, and provide an air/gas mixture to the burner assembly 16. More specifically, the mixture subsystem 20 may receive and combine air and a flammable gas to yield an air/gas mixture. Air may be provided by an air source 24, such as a pressurized or compressed air system. A flammable gas, such as natural gas, may be provided by a gas source 26, such as a natural gas tank or supply system. The mixture subsystem 20 may generally be provided in a cabinet or housing 28 that may be accessible via a door. In addition, the mixture subsystem 20 may include a plurality of components described below that may be fluidly connected with pipes, fittings, and the like in a manner known by those skilled in the art.

[0017] The mixture subsystem 20 may be fluidly connected to the air source 24 via an air supply conduit 30. The air supply conduit 30 may have any suitable configuration, such as pipe, hose, or the like. The air supply conduit 30 may extend from the housing 28 to facilitate connection to the air source 24.

[0018] An air pressure regulator valve 32 may be fluidly connected to the air supply conduit 30. The air pressure regulator valve 32 may facilitate adjustment and/or regulation of the air pressure in the mixture subsystem 20. The air pressure regulator valve 32 may have any suitable configuration and may include a knob for adjusting the pressure of air provided at an outlet of the air pressure regulator valve 32.

[0019] An air pressure gage 34 may fluidly connected to the output of the air pressure regulator valve 32 to provide information regarding the air pressure provided by the air pressure regulator valve 32.

[0020] An air solenoid valve 36 may also be fluidly connected to the outlet of the air pressure regulator valve 32. The air solenoid valve 36 may include a solenoid that actuates a valve or similar device between an open position and a closed position. In the open position, air is permitted to flow through the air solenoid valve 36. In the closed position, air may be inhibited from flowing through the air solenoid valve 36. The air solenoid valve 36 may be configured such that it is normally open when power is provided to the system 10. The air solenoid valve 36 may communicate with or be controlled by the control subsystem 22 as represented by connection point A.

[0021] A gas/air mixer 38 may be fluidly connected to the outlet of the air solenoid valve 36. Operation of the gas/air mixer 38 will be discussed in more detail below.

[0022] The mixture subsystem 20 may be fluidly connected to the gas source 26 via a gas supply conduit 40, such as a pipe or hose. The gas supply conduit 40 may extend from the housing 28 to facilitate connection to the gas source 26.

[0023] A gas supply pressure gage 42 may be fluidly connected to the gas supply conduit 40 to provide information regarding the gas pressure provided by the gas source 26.

[0024] A gas regulator 44 may also be fluidly connected to the gas supply conduit 40. The gas regulator 44 may regulate the pressure of gas provided at an outlet of the gas regulator 44. The gas regulator 44 may be of any suitable type and may include an adjustment bladder or diaphragm. The gas regulator 44 may include a vent pipe 46 that facilitates the release of gas when gas pressure exceeds a predetermined pressure level.

[0025] A gas regulator pressure gage 48 may be fluidly connected to the gas regulator 44 to provide information regarding the gas pressure provided by the gas regulator 44.

[0026] A gas solenoid valve 50 may also be fluidly coupled to the outlet of the gas regulator 44. The gas solenoid valve 50 may include a solenoid that actuates a valve or similar device between an open position and a closed position. In the open position, gas is permitted to flow through the gas solenoid valve 50. In the closed position, gas may be inhibited from flowing through the gas solenoid valve 50. The gas solenoid valve 50 may be configured such that it is normally closed when power is provided to the system 10. The gas solenoid valve 50 may communicate with or be controlled by the control subsystem 22 as represented by connection point B.

[0027] The gas/air mixer 38 may receive air and gas and mix them to provide a gas/air mixture. More specifically, the gas/air mixer 38 may include an air inlet that is fluidly connected to the outlet of the air solenoid valve 36 and a gas inlet that is fluidly connected to the outlet of the gas solenoid valve 50. The air and gas mix in the gas/air mixer to yield a gas/air mixture that may be expelled at an outlet. The gas/air mixer 38 may be of any suitable type, such as a Venturi-type mixer.

[0028] A gas/air mixture pressure gage 52 may be fluidly connected to the outlet of the gas/air mixer 38 to provide information regarding the pressure of the gas/air mixture provided by the gas/air mixer 38.

[0029] A gas control valve 54 may be fluidly connected to the outlet of the gas/air mixer 38. The gas control valve 54 may have any suitable configuration and may include a knob for adjusting the pressure of the gas/air pressure provided at an outlet of the gas control valve 54.

[0030] A conduit 56, such as hose, may be fluidly connected the outlet of the gas control valve 54. The conduit 56 may fluidly connect the mixture subsystem 20 to the burner assembly 16.

[0031] Referring to FIG. 3, the burner assembly 16 is shown in more detail. In at least one embodiment, the burner assembly 16 may include a handle portion 60 and a burner portion 62.

[0032] The handle portion 60 may include a supply tube 70, a handle 72, a trigger 74, a trigger guard 76, and a switch 78.

[0033] The supply tube 70 may fluidly connect the conduit 56 to the burner portion 62. The supply tube 70 may extend through the handle 72 and may include fittings at opposing ends that facilitate coupling to the conduit 56 and burner portion 62, respectively. The supply tube 70 may be made of any suitable material, such as a metal like stainless steel.

[0034] The handle 72 may facilitate grasping of the burner assembly 16 by a user. As such, the burner assembly 16 may be handheld. In addition, the present invention contemplates embodiments that may not be handheld. As such, the handle 72 and other components like the trigger 74, trigger guard 76, and switch 78 may be deleted or relocated. The handle 72 may be made of any suitable material, such as a polymeric material to reduce weight.

[0035] The trigger 74 may be moveably disposed on the handle 72 and be configured to actuate the switch 78. In the embodiment shown, the trigger 74 is configured to pivot about a pivot pin. A spring may be provided that exerts a biasing force that actuates the trigger 74 away from the switch 78 when sufficient force is not provided by a user. Alternatively, the trigger 74 may be omitted in one or more embodiments and the switch 78 may be directly actuated by a user.

[0036] The trigger guard 76 may be disposed on the handle 72. In the embodiment shown, the trigger guard 76 is generally U-shaped and is spaced apart the trigger 74 to provide space for the hand of a user to grip the handle 72 and trigger 74. The trigger guard 76 may generally extend around the trigger 74 to help inhibit inadvertent actuation of the trigger 74, such as may otherwise occur if the burner assembly 16 was dropped and the trigger 74 was inadvertently actuated.

[0037] The switch 78 may facilitate the flow and/or ignition of the gas/air mixture. The switch 78 may be disposed on the handle 72 and may be electrically connected to the control subsystem in any suitable manner as represented by connection point C. The switch 78 may have an on position and an off position. In the on position, the flow and/or ignition of the gas/air mixture to the burner portion 60 may be enabled. In the off position, the flow and/or ignition of the gas/air mixture to the burner portion 60 may be disabled.

[0038] The burner portion 62 may be spaced apart from the handle 72. In at least one embodiment, the burner portion 62 may include a burner unit 80, electrode assembly 82, and one or more sensors 84.

[0039] The burner unit 80 may be configured to receive and distribute the gas/air mixture. The burner unit 80 may include an inlet that is fluidly connected to the supply tube 70, a manifold cavity 86, and a distribution outlet 88.

[0040] The manifold cavity 86 may distribute the gas/air mixture to the distribution outlet 88. In at least one embodiment, the manifold cavity 86 may be a channel that extends between opposing ends or end plates of the burner unit 80. In an embodiment having one or more end plates, a gasket may be provided between the end plate and the body of burner unit 80 to inhibit leakage of the gas/air mixture.

[0041] The distribution outlet 88 may be disposed adjacent to the manifold cavity 86 and may include a plurality of openings through which the gas/air mixture may pass. The openings may be provided with a screen, ribbon pack, or structure that at least partially defines the openings. For instance, a ribbon pack may include a plurality of ribbon-shaped members having a serpentine configuration. The distribution outlet 88 may cooperate with the manifold cavity 86 to help distribute the gas/air mixture in a predetermined manner. For example, the manifold cavity 86 and distribution outlet 88 may distribute the gas/air mixture at a substantially even pressure and/or flow rate through the distribution outlet 88 which may help provide laminar flow of the gas/air mixture. Moreover, the distribution and/or flow of the gas/air mixture may help provide visible flame cones that help a user position the burner assembly 16 with respect to the workpiece 12.

[0042] The electrode assembly 82 may be disposed proximate the burner unit 80. In the embodiment shown, the electrode assembly 82 is disposed on a mounting bracket 90 that is mounted to the burner unit 80. The electrode assembly 82 may also be disposed in the burner unit 80 in one or more embodiments.

[0043] The electrode assembly 82 may be configured to receive electrical current and provide a spark or arc that ignites the gas/air mixture. The electrode assembly 82 may include an output end that may include or be coupled to a flame rod 92. The flame rod 92 may be made of an electrically conductive material, such as stainless steel. The flame rod 92 may have a distal end that may be located near but spaced apart from the burner unit 80 and/or distribution outlet 88. A spark or arc may be created between the distal end and the burner unit 80 and/or distribution outlet upon application of sufficient electrical current.

[0044] The electrode assembly 82 may also include an input end disposed opposite the flame rod 92 that may be coupled to an electrical cable. The cable may also facilitate communication with or control by the control subsystem 22 as represented by connection point D.

[0045] The electrode assembly 92 may provide feedback regarding whether a flame has ignited. Flame ignition may be detected by detecting a change in current flow. For instance, a higher current level may be indicative of flame ignition while a lower current level may be indicative of the absence of ignition.

[0046] The electrode current level may be displayed on a current gage 94 to provide feedback to a user. The current gage 94 may be located in any suitable location, such as on the housing 28 and may be in communication with the control subsystem 22 as represented by connection point E.

[0047] One or more sensors 84 may be provided to detect one or more attributes associated with the operation of the burner assembly 16. For example, the sensor 84 may be configured to detect the temperature of the workpiece. A temperature sensor may be positioned such that it is disposed proximate a region of the workpiece 12 after flame treatment. In addition, the sensor 84 may be configured to detect the proximity of the burner unit 80 to the workpiece. The sensor 84 may also be configured to detect the speed or velocity at which the burner unit 80 moves with respect to the workpiece 12. For simplicity, the sensor 84 shown in FIG. 3 may represent one or more of the sensors discussed above. The sensor or sensors 84 may be of any suitable type and may communicate with or be controlled by the control subsystem 22 as represented by connection point F.

[0048] The system 10 may also include a feedback device 98 that may provide sensory feedback to an operator. The feedback device 98 may be disposed in any suitable location, such as on the supply unit 14, the burner assembly 16, or remotely from these components. The feedback device 98 may be of any suitable type. For instance, the feedback device 98 may provide an audible and/or a visual signal to an operator. The feedback device 98 may communicate with the control subsystem 22 wirelessly or via a cable as represented by connection point G.

[0049] Referring to FIG. 4, another embodiment of a burner system 10' is shown. The burner system 10' may have a configuration similar to the burner system 10 previously described. In this embodiment, the burner system 10' is disposed on a cart to facilitate transportation. Such a configuration may be suitable for use in car dealerships or garages which may receive more limited benefits from a stationary cabinet or system. The system 10' may include quick connect fittings to facilitate air and gas connections.

[0050] Referring to FIG. 5, a flowchart depicting a method of control is shown. The method may be implemented and/or controlled by the control system 22 in a manner known by those skilled in the art. The method steps are described below based on an initial condition in which power is turned off and the flow of air and gas is disabled.

[0051] At 100, the method begins when system power is turned on. Power may be turned on with a master power switch that may be disposed on the housing 28.

[0052] At 102, the flow of air is enabled. The flow of air may be enabled by the control subsystem 22, which may signal the air solenoid valve 36 to open. As such, air may flow through the mixture subsystem 20, conduit 56, and burner assembly 16.

[0053] At 104, the method determines whether the trigger is actuated. Determination of whether the trigger 74 is actuated may be based on a signal from the trigger switch 76. If the trigger 76 is actuated, the method continues at block 106. If the trigger 76 is not actuated, the method may return to block 102.

[0054] For simplicity, the steps that follow are described with the presumption that the trigger 74 has been and continues to be actuated. If the trigger 74 is no longer actuated, the method may return to block 102.

[0055] At 106, the flow of gas is enabled. The flow of gas may be enabled by the control subsystem 22, which may signal the gas solenoid valve 50 to open. As such, gas may flow through the mixture subsystem 20, mix with air in the gas/air mixer 38, and flow to the burner assembly 16 via conduit 56.

[0056] At 108, the electrode assembly 82 is energized to provide a spark or arc to ignite the gas/air mixture. The electrode assembly 82 may be energized by the control subsystem 22 which may provide a predetermined electrical current.

[0057] At 110, the method determines if a flame is detected. A flame may be detected by monitoring electrical attributes of the electrode assembly 82. For example, the presence of a flame may be indicated by a change in current flowing through the electrode assembly and/or a connection cable. In at least one embodiment, a current sensor may be provided with the control system 22 that detects the current level. The current level or change in current may be compared to a threshold value or range that may be indicative of the presence of a flame. For instance, a flame may not be present if the current level drops below a threshold current value. Flame detection may also be associated with a predetermined period of time. For instance, if a flame is detected within the predetermined period of time, the method may continue at block 112. If a flame is not detected within the predetermined period of time, the method continues at block 114.

[0058] At 112, the method determines if a fault is detected. Detection of a fault may be based on a signal from one or more sensors 84. For example, for a distance or proximity sensor, a distance fault may exist when the burner unit 80 is too close and/or too far from the workpiece 12. A speed fault may exist when the speed at which the burner unit 80 is moved relative to the workpiece 12 or a reference point is too slow and/or too fast. Slow movement may be indicative of localized workpiece overheating while fast movement may be indicative of insufficient heating. A temperature fault may exist when the temperature of the workpiece 12 exceeds a threshold value. If a fault is detected, the method may continue at block 116. If a fault is not detected, the method may return to block 110.

[0059] At 114, the flow of gas is disabled. Gas flow may be disabled by sending a signal to close the gas solenoid valve 50. As such, air may continue to flow through the mixture subsystem 20, conduit 56, and burner assembly 16 to help purge the gas/air mixture from the system 10.

[0060] At 116, a warning signal is provided. The warning signal may be of any suitable type, such as audible, visual, or combinations thereof. The warning signal may be provided by the feedback device 98.

[0061] At 118, the method determines if the fault continues to exist. Determination of whether a fault continues to exist may be based on time. For example, a fault timer may be started upon the detection of a fault and stopped and/or reset when a fault is no longer detected. If the fault timer exceeds a predetermined time value, the method may continue at block 114 where gas flow is disabled. If the fault timer does not exceed a predetermined time value, then the method continues at block 110.

[0062] The present invention may provide flexibility to flame treat parts having complex geometries, such as plastic bumper fascias. In addition, the present invention may help inhibit overheating or excessive flame treatment of a workpiece that may inhibit product quality. For instance, when a workpiece has complex contours or a high amount of flash an operator may tend to move the burner assembly slowly to more accurately direct the flame toward the workpiece. The thermal energy provided from the flame to the workpiece may result in localized melting. Such localized melting may not be easily detected by visual inspection. Localized melting may inhibit adhesion of coatings or paint subsequently applied to the workpiece. As a result, a coating or paint may chip or flake during normal transportation and handling. The system described above may help improve product quality by providing laminar flow that may provide visible flames and more even flame and heat distribution and/or feedback that may warn a user before localized melting occurs.

[0063] While the best mode for carrying out the invention has been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention as defined by the following claims.

Claims

1. A burner system comprising: a burner assembly including: a distribution outlet having a plurality of openings; and an electrode spaced apart from the distribution outlet; and a supply unit configured to provide a gas/air mixture to the burner assembly via a hose; wherein the electrode provides an electrical arc to ignite the gas/air mixture for a predetermined period of time.

2. The burner system of claim 1 wherein the gas/air mixture has substantially laminar flow through the plurality of openings.

3. The burner system of claim 1 wherein the supply unit and burner assembly are disposed on a mobile cart.

4. The burner system of claim 1 further comprising a sensor that detects temperature of a workpiece that has received thermal energy from an ignited gas/air mixture.

5. The burner system of claim 4 further comprising a feedback device that is activated when the temperature exceeds a predetermined temperature value.

6. The burner system of claim 1 further comprising a sensor that detects a speed at which the burner assembly moves relative to a workpiece.

7. The burner system of claim 6 further comprising a feedback device that is activated when the speed is less than a predetermined speed value.

8. The burner system of claim 1 further comprising a sensor that detects a distance at which the burner assembly is positioned relative to a workpiece.

9. The burner system of claim 8 further comprising a feedback device that is activated when the distance is less than a predetermined distance value.

10. The burner system of claim 1 wherein the gas/air mixture includes natural gas.

11. A method of controlling a burner system comprising: providing a gas/air mixture to a burner assembly; energizing an electrode; determining whether the gas/air mixture ignites within a predetermined period of time; determining whether a fault is detected; and providing a warning signal if a fault is detected.

12. The method of claim 11 further comprising not providing the gas/air mixture to the burner assembly if the gas/air mixture does not ignite within the predetermined period of time.

13. The method of claim 11 wherein the step of providing the gas/air mixture further comprises: providing air to a gas/air mixer and the burner assembly, the burner assembly including the electrode, a trigger, and a distribution outlet having a plurality of openings; determining whether the trigger is actuated; providing a flammable gas to a gas/air mixer when the trigger is actuated to produce the gas/air mixture; providing the gas/air mixture to the burner assembly via a flexible hose.

14. The method of claim 13 wherein the step of energizing the electrode further comprises providing an electric arc between a distal end of the electrode and the distribution outlet.

15. The method of claim 11 wherein the step of determining whether a fault is detected further comprises starting a fault timer upon the detection of the fault and stopping gas flow when the fault timer exceeds a predetermined time value.

16. The method of claim 11 further comprising detecting a temperature of a workpiece with a sensor provided with the burner assembly and stopping gas flow when the temperature exceeds a predetermined temperature value.

17. The method of claim 11 further comprising detecting a speed at which the burner assembly moves relative to a workpiece with a sensor and disabling gas flow when the speed is less than a predetermined speed value.

18. The method of claim 11 further comprising detecting a distance at which the burner assembly is positioned relative to a workpiece with a sensor and disabling gas flow when the distance is less than a predetermined distance value.

19. The method of claim 11 wherein the step of determining whether the gas/air mixture ignites within a predetermined period of time further comprises monitoring the current provided to the electrode and wherein the gas/air mixture is ignited if the current is less than a predetermined current value.