It is known to provide a heating apparatus that is capable of using more than one fuel to produce heat. These prior art devices, which may include vent-free gas heaters and vented gas heaters, must be connected to an alternating current (AC) power supply in order to function as intended.
Due to the large thermal value different between different types of fuels, these prior art devices generally have two different, separate or independent systems, one to utilize each fuel type. Prior art heating devices include a manually operable gas conversion valve, which allows or requires a user to switch between the two systems dependent upon the fuel being burned. If the gas conversion valve is incorrectly configured or adjusted, these prior art devices may not function as intended or in an efficient matter.
It would be desirable to overcome the above and other deficiencies of conventional heating devices. The system and method of the present disclosure provide such benefits.
In one embodiment, the present disclosure relates generally to a heating system capable of generating heat when supplied with either a first fuel or a second fuel. The system can include at least one main burner configured to generate heat. The at least one main burner can receive the fuel through at least one of a first inlet and a second inlet. A first pilot burner can include at least one thermocouple, and a second pilot burner can include at least one thermocouple. A supply piping assembly can be configured to supply either the first fuel or the second fuel to the at least one main burner, the first pilot burner and the second pilot burner. First and second electromagnetic valves can be operatively connected to an electrical power supply and at least one of the thermocouples. The first and second electromagnetic valves can be configured to permit and prevent the fuel from reaching at least one of the first pilot burner, the second pilot burner and the at least one main burner depending upon thermoelectric potential received from the at least one of the thermocouples.
The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings various illustrative embodiments. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:
Certain terminology is used in the following description for convenience only and is not limiting. Certain words used herein designate directions in the drawings to which reference is made. Unless specifically set forth herein, the terms “a,” “an” and “the” are not limited to one element, but instead should be read as meaning “at least one.” The terminology includes the words noted above, derivatives thereof and words of similar import.
Referring to the drawings in detail, wherein like reference numerals indicate like elements throughout,
The first fuel can be of a different type or form than the second fuel, such that a difference in thermal or heating values exists between the two fuels. In one embodiment, the second fuel has a higher thermal value than the first fuel. For example, the first fuel can be natural gas and the second fuel can be propane, such as liquid propane. But the present disclosure is not limited to these two fuels. For example, the fuels can include any combination of liquid butane, liquefied petroleum gas (LPG), liquid gasoline, hydrogen, propane, carbon monoxide (CO) and the like. In at least one embodiment, the difference in thermal values can be relatively large, such as approximately 83,000 Btu/ft3. However, such a large different in thermo values between the two fuels is not required. Alternatively, the difference in thermo values between the two fuels can be greater than 83,000 Btu/ft3 or even significantly less.
The heating system 100 includes at least one main burner 1 configured to generate heat. A bracket 19 (
In operation, and as described in detail below, the first inlet 8 alone is sized, shaped and/or configured to provide the main burner 1 with a sufficient amount of fuel to generate a desired heat production when the second fuel is supplied. Thus, in at least one embodiment, the second inlet 7 does not provide, or is prevented from providing, any or an appreciable amount of fuel to the main burner 1 when the second fuel is burned. However, the second inlet 7 is configured to provide the main burner 1 with additional amount of fuel when the first fuel is burned, so that the heat output of the heating system 100 is able to reach the required or expected level.
As shown in
At least a portion of the first and second thermocouples 15, 14 are positioned within a flame sensible area of the first burner 12 when the first pilot burner 11 is burning the first fuel (e.g., natural gas). The term “flame sensible area” is broadly defined herein as the range, reach or coverage of a flame. The third thermocouple 16 is located at least slightly further away from the first burner 12, as compared to the first and second thermocouples 15, 14. More particularly, the entire third thermocouple 16 is located at least slightly outside of the flame sensible area of the first burner 12 when the first burner 12 is burning the first fuel. However, at least a portion of the third thermocouple 16 is located within the flame sensible area of the first burner 12 when the first burner 12 is burning the second fuel (e.g., liquid propane).
As shown in
A diameter of an orifice of the first burner 12 of the first pilot burner 11 can be larger than a diameter of an orifice of the second burner 20 of the second pilot burner 37. As a result of the smaller size of the second burner 20 and/or the lower thermal values of the first fuel, when the second burner 20 burns the first fuel, a flame produced by the second burner 20 cannot reach or affect either the fourth or fifth thermocouples 22, 21 of the second pilot burner 37. In other words, the fourth and fifth thermocouples 22, 21 are outside of the flame sensible area of the second burner 20 when the first fuel is burned. The first pilot burner 11 can be located on a first side of the main burner 1, while the second pilot burner 37 can be located on an opposite side of the main burner 1.
A supply piping assembly, generally designated 31, is configured to supply a either the first fuel or the second fuel to the main burner 1, the first pilot burner 11 and the second pilot burner. 37. The supply piping assembly 31 can include a fuel fitting 24, a fuel regulator 65 and a main gas supply pipe 66. The supply piping assembly 31 can be removably attachable to a source of fuel, such as a tank or fuel line, such that that heating system 100 can be portable.
User controls can be located at or near a top of the outer housing 32 of the heating system 100 to allow a user to initiate and/or control heating. For example, in one embodiment, a control valve 25 is operatively connected to at least one thermocouple of the first pilot burner 11 and to at least one thermocouple of the second pilot burner 37. In one embodiment, the control valve 25 is movable to and/or between an OFF position, a PILOT or IGNITION position, and an ON position or range. In the OFF position, fuel is prevented from reaching the main burner 1, the first pilot burner 11 and the second pilot burner 37. In the PILOT position, fuel is allowed to reach the first pilot burner 11 and the second pilot burner 37, but can be prevented from reaching the main burner 1 (such as by a position or configuration of a thermostat 33, described in more detail below). In the ON position, fuel can be permitted to flow to the main burner 1, the first pilot burner 11 and the second pilot burner 37. The control valve 25 can be biased to the OFF position, as described in detail below. A cover 67 enclosing a printed circuit board (PCB) may be operatively connected to the control valve 25 and other components of the heating system 100 via electrical wiring or cables.
According to one embodiment, only after the control valve 25 is depressed a predetermined distance in the PILOT position is fuel permitted to flow to the first and second pilot burners 11, 37. In addition, it can be desirable to depress the control valve 25 for a predetermined amount of time (e.g., 5-30 seconds) in the PILOT position even after the first and second burners 12, 20 are ignited. This allows for the thermocouples to generate sufficient thermoelectric potential for the system 100 to function as intended.
An ignition button 35, which alternatively can be a switch, can be operatively connected to an electrical power supply and the first and second ignition electrodes 13, 23 via electrical wiring or cables. The ignition button 35 can be operable by a user to cause the first ignition electrode 13 and the second ignition electrode 23 to produce a spark when the control valve 25 is in the PILOT position. In such a configuration, the control valve 25 is movable from the IGNITION position to the ON position after the heating system 100 is ignited, as described in detail below.
A main burner pipe 27 operatively connects the control valve 25 to the first and second inlets 8, 7 of the main burner 1. The main burner pipe 27 can include a first T-joint 28b, which allows the main burner pipe 27 to be divided between the first inlet 8 and the second inlet 7. The thermostat 33 can be located in or attached to the main burner pipe 27. The thermostat 33 may be separate and spaced-apart from the control valve 25 (see
A pilot burner pipe 26 operatively connects the control valve 25 to the first and second pilot burners 11, 37. The pilot burner pipe 26 can include a second T-joint 28a, which allows the pilot burner pipe 26 to be divided between the first pilot burner 11 and the second pilot burner 37. In particular, a first gas manifold 29 connects the second T-joint 28a to the first pilot burner 11, and a second gas manifold 30 connects the second T-joint 28a to the second pilot burner 37.
Electrical power can be supplied to the heating system 100 by the electrical power supply 36. In one embodiment, the electrical power supply 36 can be a battery pack. The battery pack can be removably attachable to the outer housing 32, and can be rechargeable. The battery pack 36 can include sufficient electrical potential to be usable for at least one season (e.g., winter) before needing to be replaced or recharged. Alternatively, the electrical power supply 36 can be a power cord configured to operatively connect to an electrical wall socket.
A first electromagnetic valve 38 is positioned in or attached to the pilot burner pipe 26 between the second T-joint 28a and the first pilot burner 11. The first electromagnetic valve 38 can be operatively connected to the electrical power supply 36, the ignition button 35 and at least one thermocouple of the first pilot burner 11, such as via electrical wiring or cable 34c, 34d. The first electromagnetic valve 38 is configured to permit or prevent fuel from reaching the first pilot burner 11 depending upon thermoelectric potential received or transferred from the at least one thermocouple of the first pilot burner 11. More particularly, the first electromagnetic valve 38 is operatively connected to both the second and third thermocouples 14, 16 of the first pilot burner 11.
Initially or prior to operation of the system 100, the first electromagnetic valve 38 can be biased to a closed position. During or by ignition of the system 100, the first electromagnetic valve 38 can be moved to an open position. In addition, a position (e.g., open or closed) of the first electromagnetic valve 38 can depend upon the existence and/or amount of thermoelectric potential received from at least one thermocouple of the first pilot burner 11. More particularly, in one embodiment, a position of the first electromagnetic valve 38 depends upon the thermoelectric potential received or transferred from the second and third thermocouples 14, 16 of the first pilot burner 11.
In operation, the first electromagnetic valve 38 can be maintained in an open position during operation of the heating system 100 when the first fuel is supplied by the supply piping assembly 31. The first electromagnetic valve 38 can be moved to the closed position during operation of the heating system 100 when the second fuel is supplied by the supply piping assembly 31. More particularly, by engagement of the ignition button 35, the first electromagnetic valve 38 can be closed. Following ignition, the first electromagnetic valve 38 can be opened or closed automatically according to thermoelectric potential received or transferred from the second and third thermocouples 14, 16. In other words, the first electromagnetic valve 38 is only powered by the battery pack 36 during an ignition period, which allows for a relatively long service or operational life of the battery pack 36.
The second and third thermocouples 14, 16 can be connected such that their individual thermoelectric potential will cancel each other out. For example, when the first pilot burner 11 is burning the first fuel (e.g., natural gas), at least a portion of the second thermocouple 14 can be within the flame sensible area, while the entire third thermocouple 16 can be at least slightly outside of the flame sensible area. In that situation, the second thermocouple 14 will generate thermoelectric potential, but the third thermocouple 16 will not. The combined thermoelectric potential transferred to or received by the first electromagnetic valve 38 will maintain the control valve 25 in the ON position after the ignition button 35 is released.
Similarly, when the first pilot burner 11 is burning the second fuel (e.g., liquid propane), the pilot flame of the first pilot burner 11 will be longer or greater at least in part because of the higher thermal value of the second fuel. In that situation, at least a portion of both the second and third thermocouples 14, 16 will be within the flame sensible area and, thereby, generate thermoelectric potential. However, the thermoelectric potential of the third or inverse thermocouple 16 can cancel that of the second thermocouple 14. Thus, the combined thermoelectric potential received by or transferred to the first electromagnetic valve 38 will be dramatically reduced or even approach zero, such that first electromagnetic valve 38 cannot be maintained in the open position. In this situation, after the ignition button 35 is released, the first electromagnetic valve 38 will immediately shut off the fuel supply to the first burner 12.
In one embodiment, as shown in
A second electromagnetic valve 64 is positioned in or attached to the main burner pipe 27 between the first T-joint 28b and the second inlet 7 of the main burner 1. The second electromagnetic valve 64 can be operatively connected to the electrical power supply 36, the ignition button 35 and at least one thermocouple of the second pilot burner 37. More particularly, the second electromagnetic valve 64 is operatively connected to the fifth thermocouple 21 of the second pilot burner 37. The second electromagnetic valve 64 can include the same or similar components as the first electromagnetic valve 38 shown and described herein.
The second electromagnetic valve 64 can be biased to an open position. A position of the second electromagnetic valve 64 can depend upon the existence and/or amount of thermoelectric potential received from the at least one thermocouple (e.g., the fifth thermocouple 21) of the second pilot burner 37. The second electromagnetic valve 64 can be configured to permit or prevent fuel from reaching the second nozzle 7 depending upon thermoelectric potential received from the at least one thermocouple (e.g., the fifth thermocouple 21) of the second pilot burner 37. For example, the second electromagnetic valve 64 can initially be in an open position, and then moved to a closed position during or by ignition of the system 100.
More particularly, in one embodiment, by engagement of the ignition button 35, the second electromagnetic valve 64 is moved or reconfigured to a closed position. Following ignition, the second electromagnetic valve 64 will be maintained in an open position or closed position, automatically, according to the existence and/or amount of thermoelectric potential received or transferred from the fifth thermocouple 21. In other words, the second electromagnetic valve 64 is only powered by the battery pack 36 during an ignition period, which allows for the relatively long service life of the battery pack 36.
In operation, at ignition when burning the first fuel (e.g., natural gas), the first electromagnetic valve 38 can be moved to an open position such that both the first and second pilot burners 11, 37 are supplied with the first fuel. In this configuration, the first burner 12 of the first pilot burner 11 produces an average or normal size flame, while the second burner 20 of the second pilot burner 37 produces a flame having a smaller size than that of the first burner 12. After ignition, the first electromagnetic valve 38 remains open, the first burner 12 of the first pilot burner 11 maintains the average or normal size flame, and the second burner 20 of the second pilot burner 37 maintains the smaller size flame. In addition, after ignition, the second electromagnetic valve 64 returns to its initial open position, such that the first fuel can continue to flow to the main burner 1 through the first and second inlets 8, 7.
At ignition when burning the second fuel (e.g., liquid propane), the first electromagnetic valve 38 can moved to an open position such that both the first and second pilot burners 11, 37 are supplied with the second fuel. In this configuration, the first burner 12 of the first pilot burner 11 produces a flame having a relatively large size, while the second burner 20 of the second pilot burner 37 produces an average or normal size flame. After ignition, the first electromagnetic valve 38 returns to its initial closed position, the flame produced by the first burner 12 of the first pilot burner 11 is extinguished, and the second burner 20 of the second pilot burner 37 produces an average or normal size flame. In addition, after ignition, the second electromagnetic valve 64 is maintained in the closed position, such that second fuel flows to the main burner 1 only through the first inlet 8, and not through the second inlet 7.
When the second pilot burner 37 is burning the second fuel (e.g., liquid propane), at least a portion of the fifth thermocouple 21 is located within the flame sensible area of the second burner 20. As a result, the fifth thermocouple 21 will generate thermoelectric potential, which will cause the second electromagnetic valve 64 to be maintained in a closed position to prevent fuel from reaching the second inlet 7 connected to the main burner 1. In contrast, when the second pilot burner 37 is burning the first fuel (e.g., natural gas), the pilot flame of the second burner 20 will be shorter or smaller due to the lower thermal valve of the first fuel (as compared to the second fuel). As a result, the entire fifth thermocouple 21 will be at least slightly outside of the flame sensible area, such that the pilot flame of the second burner 20 will not be able to reach the fifth thermocouple 21. After the ignition button 35 is released, the second electromagnetic valve 64 will be maintained in an open position to permit fuel to reach the second inlet 7 connected to the main burner 1.
In one embodiment, the first thermocouple 15 of the first pilot burner 11 and the fourth thermocouple 22 of the second pilot burner 37 are operatively connected to the control valve 25 by electrical wiring or cable 34a, 34b. In that embodiment, thermoelectric potential generated by the first thermocouple 15 or the fourth thermocouple 22 can maintain the control valve 25 in the ON position when the control valve 25 is released by a user. If either the first thermocouple 15 or the fourth thermocouple 22 does not create sufficient thermoelectric potential, in this embodiment the control valve 25 would be moved to the OFF position.
The present invention is not limited to inclusion of the separate ignition button 35, as shown and described herein. Instead, in one embodiment, the control valve 25 can be movable (e.g., rotatable), as described above between an OFF position and an ON position, and depressible. For example, when the control valve 25 is pressed downward, the battery pack 36 can be engaged such that power is provided to both the first and second electromagnetic valves 38, 64. When the control valve 25 is released and permitted to return to an “up” position, power will be cut from the battery pack 36 to the first and second electromagnetic valves 38, 64.
If the second fuel is provided to the heating system 100 instead of the first fuel, ignition of the second fuel (step 1404) causes thermoelectric potential to be created or produced from at least one of the thermocouples, such as the fifth thermocouple 21, of the second pilot burner 37 (step 1406b). This is because the entire fifth thermocouple 21 will be within the flame sensible area of the second burner 20. The second electromagnetic valve 64 is then maintained in a closed position based on the thermoelectric potential received from the thermocouples of the second pilot burner 37 (step 1408b). The first electromagnetic valve 38 is also to move to a closed position based on the absence or reduced amount of thermoelectric potential received from the thermocouple, such as the second thermocouple 14 of the first pilot burner 11 (step 1408b). This is because the entire second thermocouple 14 will be at least slightly outside of the flame sensible area of the first burner 12. As a result, the second fuel is prevented from flowing to the second inlet 7 of the main burner 1 and to the first pilot burner 11, but is permitted to flow to the first inlet 8 of the main burner 1 and to the second pilot burner 37.
The above-described components and processes allow the heating system 100 to utilize input received from one or more thermocouples to identify fuel type or source. The heating system 100 is able to automatically modify its configuration to account for the type of fuel being provided. Manual conversion of the heating system 100 is not required, as is common with prior art heating systems. As a result of these and other factors, the risk of malfunction is reduced and efficiency is increased.
One or more of the above-described systems and/or methods may be implemented with or involve software, for example modules executed on or more computing devices 1510 (see
Each computing device 1510 may include one or more processing devices 1511 designed to process instructions, for example computer readable instructions (i.e., code), stored in a non-transient manner on one or more storage devices 1513. By processing instructions, the processing device(s) 1511 can perform one or more of the steps and/or functions disclosed herein. Each processing device can be real or virtual. In a multi-processing system, multiple processing units can execute computer-executable instructions to increase processing power. The storage device(s) 1513 can be any type of non-transitory storage device (e.g., an optical storage device, a magnetic storage device, a solid state storage device, etc. The storage device(s) 1513 can be removable or non-removable, and include magnetic disks, magnetic tapes or cassettes, CD-ROMs, CD-RWs, DVDs, or any other medium which can be used to store information. Alternatively, instructions can be stored in one or more remote storage devices, for example storage devices accessed over a network or the internet.
Each computing device 1510 additionally can have memory 1512, one or more input controllers 1516, one or more output controllers 1515, and/or one or more communication connections 1540. The memory 1512 can be volatile memory (e.g., registers, cache, RAM, etc.), non-volatile memory (e.g., ROM, EEPROM, flash memory, etc.), or some combination thereof. In at least one embodiment, the memory 1512 can store software implementing described techniques.
An interconnection mechanism 1514, such as a bus, controller or network, can operatively couple components of the computing device 1510, including the processor(s) 1511, the memory 1512, the storage device(s) 1513, the input controller(s) 1516, the output controller(s) 1515, the communication connection(s) 1540, and any other devices (e.g., network controllers, sound controllers, etc.). The output controller(s) 1515 can be operatively coupled (e.g., via a wired or wireless connection) to one or more output devices 1520 (e.g., a monitor, a television, a mobile device screen, a touch-display, a printer, a speaker, etc.) in such a fashion that the output controller(s) 1515 can transform the display on the display device 1520 (e.g., in response to modules executed). The input controller(s) 1516 can be operatively coupled (e.g., via a wired or wireless connection) to an input device 1530 (e.g., a mouse, a keyboard, a touch-pad, a scroll-ball, a touch-display, a pen, a game controller, a voice input device, a scanning device, a digital camera, etc.) in such a fashion that input can be received from a user.
The communication connection(s) 1540 enable communication over a communication medium to another computing entity. The communication medium conveys information such as computer-executable instructions, audio or video information, or other data in a modulated data signal. A modulated data signal is a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media include wired or wireless techniques implemented with an electrical, optical, RF, infrared, acoustic, or other carrier.
One distinguishing feature of the embodiment of
The CFDV 68 can include a control knob 69 movable connected to a valve body 78. The valve body 78 having a first fluid channel 74a and a second fluid channel 74b spaced-part therefrom. An ignition switch 70 can be installed beneath the control knob 69 and can be operatively connected to the electrical power supply 36. The CFDV 68 can include first and second inlet interfaces 71a, 71b and first and second outlet interfaces 72a, 72b, which are fluidly connected by the first and second fluid channels 74a, 74b, respectively. The first and second inlet interfaces 71a, 71b are configured to receive fuel from first and second outlet interfaces 73a, 73b, respectively, of the control valve 25 through first and second T-joints 88a, 88b, respectively. The first and second outlet interfaces 72a, 72b are in fluid communication with the first burner 12 of the first pilot burner 11 and the main burner 1 through the second nozzle 5.
The CFDV 68 can also include a first electromagnetic valve 58a spaced-apart from a second electromagnetic valves 58b. The first and second electromagnetic valves 58a, 58b are attached and/or operatively connected to the first and second fluid channels 74a, 74b, respectively. More specifically, at least a portion of the first and second electromagnetic valves 58a, 58b can be attached to and/or located inside of the valve body 78 at an opposite end from the control knob 69. The first and second electromagnetic valves 58a, 58b can be operatively connected, via electrical wires, for example, to at least one of the thermocouples.
In one version, the CFDV 68 is biased to a closed position, such that the first and second gas channels 74a, 74b are closed (see
In a second version, the CFDV 68 is biased to an open position, such that at least the second gas channel 74b is open (see
In the embodiment in which the CFDV 68 is biased closed (see
At this point, if the control valve 25 is maintained in the depressed position and the control knob 69 of the CFDV 68 is also depressed at least a predetermined amount (thereby opening the CFDV 68), fuel will flow to the first burner 12 of the first pilot burner 11. Simultaneously, a contacting rod 75 (see
At ignition when burning the second fuel (e.g., liquid propane), the second burner 20 of the second pilot burner 37 will produce an average size flame. As a result, the fourth thermocouple 22, which will be within reach of the average size flame of the second burner 20, will generate thermoelectric potential to maintain the control valve 25 in an open position. Simultaneously, the first burner 12 of the first pilot burner 11 will produce a relatively large flame due, at least in part, to the larger orifice of the first burner 12. As a result, the flame produced by the first burner 12 will reach each of the first thermocouple 15, the second thermocouple 14 and the third thermocouple 16. Because the second thermocouple 14 is inversely connected to the third thermocouple 16, any combined thermoelectric potential transferred to the CFDV 68 will be negligible or zero, such that the first and second electromagnetic valves 58a, 58b will not be energized to maintain the CFDV 68 in the open. At this point, if or after the knob 69 of the CFDV 68 is released by the user, the first and second gas channels 74a, 74b of the CFDV 68 will be closed position and the flame of the first burner 12 of the first pilot burner 11 is immediately extinguished.
After ignition, when both the CFDV 68 and the control valve 25 are released by the user, the second burner 20 of the second pilot burner 37 continues to burn normally as the control valve 25 is in an open position and the CFDV 68 is closed. The control valve 25 can then be moved or rotated from the IGNITION position to the ON position, such that the fuel reaches the second T-joint 88b and is then divided in two ways. First, at least some of the fuel flows to the second gas channel 74b of the CFDV 68 and is stopped there because the second gas channel 74b is closed. Second, at least some of the fuel flows to the main burner 1 through the first nozzle 6.
At ignition when burning the first fuel (e.g., natural gas), the second burner 20 of the second pilot burner 37 will produce a relatively small flame due, at least in part, to the relatively small orifice of the second burner 20. However, the first burner 12 of the first pilot burner 11 will produce a relatively average size flame, which will reach the first thermocouple 15 and the second thermocouple 14. The third thermocouple 16 will be outside of the range of the flame produced by the first burner 12 and, therefore, will not and cannot generate inverse thermoelectric potential. As a result, thermoelectric potential generated by the second thermocouple 14 will maintain the control valve 25 in an open position, while the thermoelectric potential generated by the first thermocouple 15 will maintain the CFDV 68 in an open position.
After ignition, when both the CFDV 68 and the control valve 25 are released by the user, the first burner 12 of the first pilot burner 11 continues to burn with the average size flame and the second burner 20 of the second pilot burner 37 continues to burn with the relatively small flame. As a result, both the CFDV 68 and the control valve 25 are maintained in an open position. When the control valve 25 is moved or rotated from the IGNITION position to the ON position, fuel reaches the second T-joint 88b and then is divided in two ways. First, at least some of the fuel flows to the second gas channel 74b of the CFDV 68 and eventually reaches the main burner 1 through the second nozzle 5. Second, at least some of the fuel reaches the main burner 1 through the first nozzle 6. The first and second nozzles 6, 5 can be designed such that the first nozzle 6 will match or achieve the designed heat input when burning the second fuel (e.g., liquid propane) and the second nozzle 5 supplements the first nozzle 6 by helping to match or achieve the designed heat input when burning the first fuel (e.g., natural gas).
At ignition in the embodiment in which the CFDV 68 is biased open (see
When burning the first fuel (e.g., natural gas), the second burner 20 of the second pilot burner 37 produces a relatively small flame, which is unable to reach the fifth thermocouple 21 of the second pilot burner 37. As a result, the fifth thermocouple 21 does not generate sufficient thermoelectric potential to energize the second electromagnetic valve 58b, which will allow the second fluid channel 74b to move to an open position once the control knob 69 is released by the user. As a result, fuel flows to the main burner 1 through the second nozzle 5, as well as through the first nozzle 6.
It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. For example, the steps or order of operation of the above-described method could be rearranged or occur in a different series, as understood by those skilled in the art. It is understood, therefore, that this disclosure is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present disclosure as defined by the appended claims.