US20070154856A1 - Dual fuel boiler with backflow-preventing valve arrangement - Google Patents
Dual fuel boiler with backflow-preventing valve arrangement Download PDFInfo
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- US20070154856A1 US20070154856A1 US11/324,430 US32443006A US2007154856A1 US 20070154856 A1 US20070154856 A1 US 20070154856A1 US 32443006 A US32443006 A US 32443006A US 2007154856 A1 US2007154856 A1 US 2007154856A1
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- Prior art keywords
- fuel
- burner
- heating appliance
- fired heating
- pressure regulator
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23K—FEEDING FUEL TO COMBUSTION APPARATUS
- F23K5/00—Feeding or distributing other fuel to combustion apparatus
- F23K5/002—Gaseous fuel
- F23K5/005—Gaseous fuel from a central source to a plurality of burners
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N1/00—Regulating fuel supply
- F23N1/002—Regulating fuel supply using electronic means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N2237/00—Controlling
- F23N2237/08—Controlling two or more different types of fuel simultaneously
Definitions
- the present invention generally relates to combustion apparatus and, in a preferred embodiment thereof, more particularly relates to a specially designed dual fuel burner system for a fuel-fired heating appliance such as, for example, a boiler.
- Dual fuel boilers have been supplied, primarily by power burner type boiler manufacturers, for many years.
- the ability to selectively operate a boiler, or other type of fuel-fired heating appliance, with one or the other of two different fuels is desirable to provide operation if and when the primary fuel source is interrupted.
- the pricing of the primary fuel source can be discounted if the customer agrees to accept interruption of the fuel supply by the supplier when so requested. In this event, the customer simply switches to the secondary or “backup” fuel source until the source of primary fuel is re-established by the supplier.
- a specially designed dual fuel heating appliance is provided.
- the heating appliance is representatively a dual fuel boiler and comprises fuel burner apparatus having an inlet portion, and fuel delivery apparatus operative to deliver to the fuel burner apparatus a selectively variable one of a first fuel (representatively natural gas) from a source thereof, and a second fuel (representatively propane) from a source thereof.
- a first fuel representedatively natural gas
- a second fuel representedatively propane
- the fuel delivery apparatus includes a main fuel supply line connected to the inlet portion of the fuel burner apparatus, a first fuel supply branch line connected to the main fuel supply line and connectable to the first fuel source, first valve apparatus connected in the first fuel supply branch line and being openable and closable to selectively permit and preclude flow of the first fuel therethrough, a second fuel supply branch line connected to the main fuel supply line and connectable to the second fuel source, and second valve apparatus connected in the second fuel supply branch line and being openable and closable to selectively permit and preclude flow of the second fuel therethrough.
- the first valve apparatus includes first and second electromechanical two position, two-way valves connected in series, and in opposite normal flow orientations, in the first fuel supply branch line.
- first and second electromechanical two position, two-way valves connected in series, and in opposite normal flow orientations, in the first fuel supply branch line.
- the dual fuel heating appliance which is illustrated in both single and multiple burner embodiments, additionally incorporates therein the relative first and second fuel pressure control technique disclosed in U.S. Pat. No. 6,904,873 which permits the use of either the first fuel or the second fuel, the first and second fuels having different Wobbe indexes, without modifying the supply orifice structure of the burner apparatus.
- the fuel delivery system further includes a first pressure regulator through which both of the first and second fuels must flow to reach the burner apparatus, and a second pressure regulator through which only the higher Wobbe index fuel must flow to reach the burner apparatus, the pressure regulation setting of the first pressure regulator being higher than the pressure regulation setting of the second pressure regulator.
- FIG. 1 is a schematic diagram of a representative dual fuel-fired boiler embodying principles of the present invention
- FIG. 2 is a schematic diagram of a specially designed dual fuel delivery system utilized in the boiler
- FIG. 3 is a schematic diagram of a multi-burner version of the FIG. 2 fuel delivery system.
- FIGS. 4A and 4B are enlarged scale schematic cross-sectional views of the dashed area “ 4 ” in FIG. 2 and respectively illustrate one of the electromechanical valves in FIG. 2 in its de-energized, normally closed orientation and its energized, opened position.
- FIG. 1 Schematically illustrated in FIG. 1 is a fuel-fired heating appliance which embodies principles of the present invention and is representatively a dual fuel boiler 10 . While a fuel-fired boiler is representatively illustrated, the heating appliance could be a variety of other types of dual fuel heating appliances such as, for example, a pool heater or other type of fuel-fired water heater, and principles of the present invention are not limited to boiler applications.
- the dual fuel boiler 10 includes fuel burner apparatus 12 which is representatively of a non-aspirating type, and a combustion air blower 14 used to supply the fuel burner apparatus 12 with combustion air 16 .
- the dual fuel boiler 10 is provided with a specially designed fuel delivery system 18 which is operatively associated with the burner apparatus 12 and may be utilized to selectively supply to the burner apparatus 12 either a primary first fuel 20 (representatively natural gas) or a secondary fuel 22 (representatively propane) having a Wobbe index higher than that of the first fuel 20 .
- First fuel 20 is supplied to the boiler 10 via a branch fuel supply line 24
- the second fuel 22 is supplied to the boiler 10 via a branch fuel supply line 26 .
- FIG. 2 there is schematically shown a representative single burner version of the burner apparatus 12 and the fuel delivery system 18 .
- the burner apparatus 12 is a single, non-aspirating type fuel burner 28 having incorporated therein, in an inlet head portion thereof, a fuel discharge orifice 30 .
- the fuel delivery system 18 compared to the fuel delivery system incorporated in the dual fuel boiler systems illustrated and described in U.S. Pat. No. 6,904,873, has an improved valving arrangement, later described herein, that more effectively prevents secondary fuel back pressure from potentially contaminating the primary fuel source with secondary fuel.
- the fuel delivery system 18 includes a main fuel supply line 32 coupled as shown to the branch fuel supply lines 24 , 26 and extending from its juncture therewith to the burner inlet fuel orifice 30 .
- a manual shutoff valve 34 and a pressure regulator apparatus 36 are connected as shown in the main fuel supply line 32 between the branch supply lines 24 , 26 and the fuel discharge orifice 30 .
- the pressure regulator apparatus 36 is a combination pressure regulator and safety or operating valve.
- the pressure regulator apparatus 36 may comprise separate pressure regulator and valve structures operatively connected in the main fuel supply line 32 upstream from the manual shutoff valve 34 without departing from principles of the present invention.
- a pressure regulator 38 is installed as shown in the second branch fuel supply line 26 .
- the pressure regulator 38 is a “lock-up” type regulator, of a conventional construction, which incorporates therein a check valve structure that prevents leftward fluid backflow through the regulator 38 .
- the improved valving arrangement of the fuel delivery system 18 also includes three electromechanical normally closed, two position, two-way, gas valves 40 , 42 , 44 of the solenoid/diaphragm type utilizing a linear motor output motion as later described herein.
- Valve 40 is connected in the branch fuel supply line 26 downstream of the pressure regulator 38 , and valves 42 , 44 are connected in series in the branch fuel supply line 24 , with valve 42 being upstream of the valve 44 .
- Manual shutoff valves (not shown) are connected in the branch fuel supply lines 24 and 26 , respectively upstream of the pressure regulator 38 and the electromechanical valve 42 .
- the manual shutoff valve 34 may be optionally installed, where shown, in addition to these non-illustrated manual shutoff valves.
- Each of the valves 40 , 42 , 44 has a normal or intended internal flow direction as indicated by the arrow 46 thereon.
- the electromechanical valve 40 When it is desired to supply natural gas to the boiler 10 , the electromechanical valve 40 is left closed, and the electromechanical valves 42 and 44 are electrically opened to permit natural gas to flow to the burner 12 via the lines 24 and 32 .
- the electromechanical valves 42 and 44 When it is desired to supply propane to the boiler 10 , the electromechanical valves 42 and 44 are closed and the electromechanical valve 40 is electrically opened to permit propane to flow to the burner 12 via the lines 26 and 32 .
- FIG. 4A cross-sectionally depicts the electromechanical valve 42 (which is configured similarly to the valves 40 and 44 ) in its de-energized normally closed orientation
- FIG. 4B cross-sectionally depicts the valve 42 in its energized or opened configuration
- valve 42 has an inlet end 48 , an outlet end 50 , and an internal flow passage 52 extending therethrough between the ends 48 and 50 .
- Internal flow passage 52 extends through an orifice 54 .
- the orifice 54 is blocked by a closure diaphragm 56 which is coupled to the vertically movable core 58 of the solenoid portion of the valve and spring-driven downwardly against the top side of the orifice 54 to close it against gas flow therethrough.
- the solenoid core 58 is electrically driven upwardly to thereby open the orifice 54 and permit gas flow in either direction through the internal passage 52 between the valve's inlet and outlet ends 48 , 50 .
- the electromechanical valves 42 , 44 connected in series in the natural gas branch supply line 24 are “oppositely” connected therein such that their normal flow arrows 46 are oppositely directed. Because of this unique opposite normal flow orientations of the electromechanical valves 42 , 44 in the branch line 24 , when propane is being delivered to the boiler 10 via the branch supply line 26 , propane back pressure on the natural gas valve 44 adds to the spring pressure on its diaphragm 56 so that such propane back pressure cannot lift the diaphragm off the orifice of valve 44 and permit propane backflow through the valve 44 .
- valves 42 , 44 With the valves 42 , 44 in such opposite normal flow orientations in the line 24 , natural gas flowing rightwardly through the (opened) valves 42 , 44 sequentially passes through the normal inlet 48 of the valve 42 , the normal outlet 50 of the valve 42 , the normal outlet 50 of valve 44 , and the normal inlet 48 of valve 44 . Note that if valve 44 were omitted, the propane back pressure exerted on the diaphragm 56 of valve 42 would be exerted thereon in a direction opposite to that of its diaphragm closure spring, thereby potentially lifting the diaphragm and permitting undesirable propane backflow through the single electromechanical valve 42 .
- Natural gas pressure on valve 42 in its normally closed position adds to the closure force on the diaphragm of valve 42 to thereby more positively preclude natural gas flow rightwardly through the branch line 24 .
- Natural gas backflow through the propane branch supply line 26 when the valve 40 is in its normally closed position is prevented by the check valve structure in the pressure regulator 38 , and by the diaphragm spring closure force within the valve 40 .
- either the first fuel 20 or the second fuel 22 may be supplied to the burner 28 during firing thereof.
- the first fuel 20 is delivered to the pressure regulator apparatus 36 at a pressure higher than its pressure regulation setting
- the second fuel 22 is being supplied to the burner 28 the second fuel 22 is delivered to the pressure regulator apparatus 36 at a pressure lower than its pressure regulation setting.
- the pressures of the first and second fuels 20 , 22 as they reach the burner 28 are related to one another in a manner such that the firing rate of the burner 28 is essentially the same regardless of which of the fuels 20 , 22 is being delivered thereto. This advantageously eliminates the necessity of changing out the burner orifice 30 each time a switch is made from either of the fuels 20 , 22 to the other fuel.
- the setting of the pressure regulator apparatus 36 is nominally 3.5′′ W.C.
- the first fuel (by virtue of a non-illustrated upstream pressure regulator) is delivered to the oppositely connected electromechanical valves 42 , 44 at a pressure within the range of from about 7′′ to about 14′′ W.C.
- the pressure regulator 38 is set to reduce the pressure of the second fuel 22 delivered to the electromechanical valve 40 to about 2.0′′ W.C.
- the pressure regulator apparatus 36 when the first fuel 20 is being supplied to the burner 28 the pressure regulator apparatus 36 reduces the pressure of the first fuel 20 that it receives to nominally 3.5′′ W.C. for supply to the burner 28 .
- the pressure regulator apparatus 36 does not regulate the pressure of the second fuel downwardly (since the second fuel is delivered to the pressure regulator apparatus 36 at a pressure lower than its setting), and the second fuel 22 is supplied to the burner 28 at a pressure of about 1.3′′ W.C. due to the inherent valve and supply line pressure drops.
- the pressure of the first fuel 20 being supplied to the burner orifice 30 will be a function of the setting of the pressure regulator apparatus 36
- the pressure of the second fuel 22 being supplied to the burner orifice 30 will be a function of the pressure of the second fuel 22 upstream of the pressure regulator apparatus 36 and the inherent valve and supply line pressure drops.
- the fuel delivery system 18 can be correspondingly adjusted to maintain the firing rate of the burner 28 at a substantially constant level when other combinations of fuels are coupled to the fuel delivery system for use with the burner 28 .
- FIG. 3 schematically illustrates modified burner apparatus 12 a and an associated modified fuel delivery system 18 a which may be alternatively incorporated in the dual fuel boiler 10 or other fuel-fired heating appliance.
- the modified burner apparatus 12 a depicted in FIG. 3 comprises two pluralities of burners 28 a (representatively two groups of three burners 28 a ).
- the modified fuel delivery system 18 a includes two branch fuel supply lines 32 a , each of which couples the main fuel supply line 32 to one of the two burner groups as shown.
- the modified fuel delivery system 18 a also includes two pressure regulating apparatuses 36 a , each of which is installed in one of the branch lines 32 a .
- each of the two pressure regulator apparatuses 36 a has a setting equal to that of the single pressure regulator apparatus 36 shown in FIG. 2 .
- the modified fuel delivery system 18 a is identical in construction and operation to the previously described fuel delivery system 18 shown in FIG. 2 .
- the pressure regulators 36 a are representatively set at nominally 3.5′′ W.C.
- the second fuel pressure regulator 38 is set to about 2.0′′ W.C.
- the multiple burners 28 a may be operated at substantially equal firing rates using either of the two fuels 20 and 22 without the necessity of changing out any of the burner orifices 30 a.
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- Engineering & Computer Science (AREA)
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- General Engineering & Computer Science (AREA)
- Feeding And Controlling Fuel (AREA)
Abstract
A dual fuel boiler has fuel delivery apparatus coupled to its burner section through a pressure regulator and operative to deliver to the burner section, from sources thereof, a selectively variable one of (1) a first fuel at a pressure greater than the pressure regulation setting of the pressure regulator, and (2) a second fuel at a pressure less than the pressure regulation setting, the second fuel having a Wobbe index greater that that of the first fuel. The first fuel is flowed to the burner section via a branch supply line in which first and second electromechanical two position, two-way, two position valves are installed in series in opposite normal flow orientations to thereby prevent backflow of the second fuel into the source of the first fuel.
Description
- The present invention generally relates to combustion apparatus and, in a preferred embodiment thereof, more particularly relates to a specially designed dual fuel burner system for a fuel-fired heating appliance such as, for example, a boiler.
- Dual fuel boilers have been supplied, primarily by power burner type boiler manufacturers, for many years. The ability to selectively operate a boiler, or other type of fuel-fired heating appliance, with one or the other of two different fuels (such as, for example, natural gas or propane) is desirable to provide operation if and when the primary fuel source is interrupted. Often the pricing of the primary fuel source can be discounted if the customer agrees to accept interruption of the fuel supply by the supplier when so requested. In this event, the customer simply switches to the secondary or “backup” fuel source until the source of primary fuel is re-established by the supplier.
- Conventional power burner practices are (1) to have two separate burner heads that can be interchanged to accommodate the switch back and forth between the two different types of fuel, or (2) to have back-up fuels with essentially the same Wobbe indexes such as propane-air to back up natural gas. The first listed conventional design, of course, requires a mechanical modification to the overall burner structure each time that a different fuel is to be used to fire the boiler.
- A desirably simplified technique for switching back and forth between two alternative fuel sources (a primary fuel source and an alternate or secondary fuel source) in a dual fuel boiler is illustrated and described in U.S. Pat. No. 6,904,873 to Ashton which is assigned to the same assignee as the assignee of this application, and which is hereby incorporated in its entirety herein by this reference.
- In further developing the dual fuel boiler illustrated and described in U.S. Pat. No. 6,904,873 a goal was established to provide it with a modified primary fuel/secondary fuel switching system having a valving arrangement that even more effectively prevents secondary fuel back pressure from potentially contaminating the primary fuel source with secondary fuel.
- In carrying out principles of the present invention, in accordance with a preferred embodiment thereof, a specially designed dual fuel heating appliance is provided. The heating appliance is representatively a dual fuel boiler and comprises fuel burner apparatus having an inlet portion, and fuel delivery apparatus operative to deliver to the fuel burner apparatus a selectively variable one of a first fuel (representatively natural gas) from a source thereof, and a second fuel (representatively propane) from a source thereof.
- The fuel delivery apparatus includes a main fuel supply line connected to the inlet portion of the fuel burner apparatus, a first fuel supply branch line connected to the main fuel supply line and connectable to the first fuel source, first valve apparatus connected in the first fuel supply branch line and being openable and closable to selectively permit and preclude flow of the first fuel therethrough, a second fuel supply branch line connected to the main fuel supply line and connectable to the second fuel source, and second valve apparatus connected in the second fuel supply branch line and being openable and closable to selectively permit and preclude flow of the second fuel therethrough.
- According to a key aspect of the invention, the first valve apparatus includes first and second electromechanical two position, two-way valves connected in series, and in opposite normal flow orientations, in the first fuel supply branch line. When these two valves are closed, second fuel backpressure on one of the valves is added to the diaphragm closing spring force thereof to more positively preclude the pressurized second fuel from backflowing into and contaminating the first fuel source.
- Preferably, the dual fuel heating appliance, which is illustrated in both single and multiple burner embodiments, additionally incorporates therein the relative first and second fuel pressure control technique disclosed in U.S. Pat. No. 6,904,873 which permits the use of either the first fuel or the second fuel, the first and second fuels having different Wobbe indexes, without modifying the supply orifice structure of the burner apparatus. To accomplish this, the fuel delivery system further includes a first pressure regulator through which both of the first and second fuels must flow to reach the burner apparatus, and a second pressure regulator through which only the higher Wobbe index fuel must flow to reach the burner apparatus, the pressure regulation setting of the first pressure regulator being higher than the pressure regulation setting of the second pressure regulator.
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FIG. 1 is a schematic diagram of a representative dual fuel-fired boiler embodying principles of the present invention; -
FIG. 2 is a schematic diagram of a specially designed dual fuel delivery system utilized in the boiler; -
FIG. 3 is a schematic diagram of a multi-burner version of theFIG. 2 fuel delivery system; and -
FIGS. 4A and 4B are enlarged scale schematic cross-sectional views of the dashed area “4” inFIG. 2 and respectively illustrate one of the electromechanical valves inFIG. 2 in its de-energized, normally closed orientation and its energized, opened position. - Schematically illustrated in
FIG. 1 is a fuel-fired heating appliance which embodies principles of the present invention and is representatively adual fuel boiler 10. While a fuel-fired boiler is representatively illustrated, the heating appliance could be a variety of other types of dual fuel heating appliances such as, for example, a pool heater or other type of fuel-fired water heater, and principles of the present invention are not limited to boiler applications. - The
dual fuel boiler 10 includesfuel burner apparatus 12 which is representatively of a non-aspirating type, and acombustion air blower 14 used to supply thefuel burner apparatus 12 withcombustion air 16. According to a key aspect of the present invention, thedual fuel boiler 10 is provided with a specially designedfuel delivery system 18 which is operatively associated with theburner apparatus 12 and may be utilized to selectively supply to theburner apparatus 12 either a primary first fuel 20 (representatively natural gas) or a secondary fuel 22 (representatively propane) having a Wobbe index higher than that of thefirst fuel 20.First fuel 20 is supplied to theboiler 10 via a branchfuel supply line 24, and thesecond fuel 22 is supplied to theboiler 10 via a branchfuel supply line 26. - In
FIG. 2 there is schematically shown a representative single burner version of theburner apparatus 12 and thefuel delivery system 18. Theburner apparatus 12 is a single, non-aspiratingtype fuel burner 28 having incorporated therein, in an inlet head portion thereof, afuel discharge orifice 30. According to a key aspect of the present invention, thefuel delivery system 18, compared to the fuel delivery system incorporated in the dual fuel boiler systems illustrated and described in U.S. Pat. No. 6,904,873, has an improved valving arrangement, later described herein, that more effectively prevents secondary fuel back pressure from potentially contaminating the primary fuel source with secondary fuel. - In addition to the branch
fuel supply lines fuel delivery system 18 includes a mainfuel supply line 32 coupled as shown to the branchfuel supply lines inlet fuel orifice 30. Amanual shutoff valve 34 and apressure regulator apparatus 36 are connected as shown in the mainfuel supply line 32 between thebranch supply lines fuel discharge orifice 30. - As schematically and representatively illustrated, the
pressure regulator apparatus 36 is a combination pressure regulator and safety or operating valve. Alternatively, thepressure regulator apparatus 36 may comprise separate pressure regulator and valve structures operatively connected in the mainfuel supply line 32 upstream from themanual shutoff valve 34 without departing from principles of the present invention. Apressure regulator 38 is installed as shown in the second branchfuel supply line 26. Preferably, thepressure regulator 38 is a “lock-up” type regulator, of a conventional construction, which incorporates therein a check valve structure that prevents leftward fluid backflow through theregulator 38. - The improved valving arrangement of the
fuel delivery system 18 also includes three electromechanical normally closed, two position, two-way,gas valves fuel supply line 26 downstream of thepressure regulator 38, andvalves fuel supply line 24, withvalve 42 being upstream of thevalve 44. - Manual shutoff valves (not shown) are connected in the branch
fuel supply lines pressure regulator 38 and theelectromechanical valve 42. Themanual shutoff valve 34 may be optionally installed, where shown, in addition to these non-illustrated manual shutoff valves. - Each of the
valves arrow 46 thereon. When it is desired to supply natural gas to theboiler 10, theelectromechanical valve 40 is left closed, and theelectromechanical valves burner 12 via thelines boiler 10, theelectromechanical valves electromechanical valve 40 is electrically opened to permit propane to flow to theburner 12 via thelines -
FIG. 4A cross-sectionally depicts the electromechanical valve 42 (which is configured similarly to thevalves 40 and 44) in its de-energized normally closed orientation, andFIG. 4B cross-sectionally depicts thevalve 42 in its energized or opened configuration. Likevalves valve 42 has aninlet end 48, anoutlet end 50, and aninternal flow passage 52 extending therethrough between theends Internal flow passage 52 extends through anorifice 54. When thevalve 42 is in its normally closedFIG. 4A orientation, theorifice 54 is blocked by aclosure diaphragm 56 which is coupled to the verticallymovable core 58 of the solenoid portion of the valve and spring-driven downwardly against the top side of theorifice 54 to close it against gas flow therethrough. When thevalve 42 is electrically energized to open it (seeFIG. 4B ), thesolenoid core 58 is electrically driven upwardly to thereby open theorifice 54 and permit gas flow in either direction through theinternal passage 52 between the valve's inlet andoutlet ends - According to a key aspect of the present invention, the
electromechanical valves branch supply line 24 are “oppositely” connected therein such that theirnormal flow arrows 46 are oppositely directed. Because of this unique opposite normal flow orientations of theelectromechanical valves branch line 24, when propane is being delivered to theboiler 10 via thebranch supply line 26, propane back pressure on thenatural gas valve 44 adds to the spring pressure on itsdiaphragm 56 so that such propane back pressure cannot lift the diaphragm off the orifice ofvalve 44 and permit propane backflow through thevalve 44. With thevalves line 24, natural gas flowing rightwardly through the (opened)valves normal inlet 48 of thevalve 42, thenormal outlet 50 of thevalve 42, thenormal outlet 50 ofvalve 44, and thenormal inlet 48 ofvalve 44. Note that ifvalve 44 were omitted, the propane back pressure exerted on thediaphragm 56 ofvalve 42 would be exerted thereon in a direction opposite to that of its diaphragm closure spring, thereby potentially lifting the diaphragm and permitting undesirable propane backflow through the singleelectromechanical valve 42. - Natural gas pressure on
valve 42 in its normally closed position (for example, when propane is being supplied to the boiler 10), adds to the closure force on the diaphragm ofvalve 42 to thereby more positively preclude natural gas flow rightwardly through thebranch line 24. Natural gas backflow through the propanebranch supply line 26 when thevalve 40 is in its normally closed position, is prevented by the check valve structure in thepressure regulator 38, and by the diaphragm spring closure force within thevalve 40. - By appropriately opening or closing the
electromechanical valve 40, or theelectromechanical valves first fuel 20 or thesecond fuel 22 may be supplied to theburner 28 during firing thereof. AS in the case of the dual fuel boiler apparatus illustrated and described in U.S. Pat. No. 6,904,873, when thefirst fuel 20 is being supplied to theburner 28 thefirst fuel 20 is delivered to thepressure regulator apparatus 36 at a pressure higher than its pressure regulation setting, and when thesecond fuel 22 is being supplied to theburner 28 thesecond fuel 22 is delivered to thepressure regulator apparatus 36 at a pressure lower than its pressure regulation setting. Further, the pressures of the first andsecond fuels burner 28 are related to one another in a manner such that the firing rate of theburner 28 is essentially the same regardless of which of thefuels burner orifice 30 each time a switch is made from either of thefuels - Representatively, but not by way of limitation, the setting of the
pressure regulator apparatus 36 is nominally 3.5″ W.C., the first fuel (by virtue of a non-illustrated upstream pressure regulator) is delivered to the oppositely connectedelectromechanical valves pressure regulator 38 is set to reduce the pressure of thesecond fuel 22 delivered to theelectromechanical valve 40 to about 2.0″ W.C. Accordingly, for thefuel delivery system 18 illustratively depicted inFIG. 2 , when thefirst fuel 20 is being supplied to theburner 28 thepressure regulator apparatus 36 reduces the pressure of thefirst fuel 20 that it receives to nominally 3.5″ W.C. for supply to theburner 28. - However, when the
second fuel 22 is being supplied to theburner 28, thepressure regulator apparatus 36 does not regulate the pressure of the second fuel downwardly (since the second fuel is delivered to thepressure regulator apparatus 36 at a pressure lower than its setting), and thesecond fuel 22 is supplied to theburner 28 at a pressure of about 1.3″ W.C. due to the inherent valve and supply line pressure drops. Thus, the pressure of thefirst fuel 20 being supplied to theburner orifice 30 will be a function of the setting of thepressure regulator apparatus 36, while the pressure of thesecond fuel 22 being supplied to theburner orifice 30 will be a function of the pressure of thesecond fuel 22 upstream of thepressure regulator apparatus 36 and the inherent valve and supply line pressure drops. - AS can be seen, by simply adjusting the settings of the
pressure regulating devices fuel delivery system 18 can be correspondingly adjusted to maintain the firing rate of theburner 28 at a substantially constant level when other combinations of fuels are coupled to the fuel delivery system for use with theburner 28. -
FIG. 3 schematically illustrates modifiedburner apparatus 12 a and an associated modifiedfuel delivery system 18 a which may be alternatively incorporated in thedual fuel boiler 10 or other fuel-fired heating appliance. Instead of thesingle burner 28 defining theburner apparatus 12 shown inFIG. 2 , the modifiedburner apparatus 12 a depicted inFIG. 3 comprises two pluralities ofburners 28 a (representatively two groups of threeburners 28 a). The modifiedfuel delivery system 18 a includes two branchfuel supply lines 32 a, each of which couples the mainfuel supply line 32 to one of the two burner groups as shown. The modifiedfuel delivery system 18 a also includes twopressure regulating apparatuses 36 a, each of which is installed in one of thebranch lines 32 a. Representatively, each of the twopressure regulator apparatuses 36 a has a setting equal to that of the singlepressure regulator apparatus 36 shown inFIG. 2 . In all other regards, the modifiedfuel delivery system 18 a is identical in construction and operation to the previously describedfuel delivery system 18 shown inFIG. 2 . AS in the case of thefuel delivery system 18, thepressure regulators 36 a are representatively set at nominally 3.5″ W.C., and the secondfuel pressure regulator 38 is set to about 2.0″ W.C. Thus, by simply opening thevalve 40, or thevalves multiple burners 28 a may be operated at substantially equal firing rates using either of the twofuels burner orifices 30 a. - The foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims.
Claims (18)
1. A fuel-fired heating appliance comprising:
fuel burner apparatus having an inlet portion;
pressure regulator apparatus having an outlet portion coupled to said inlet portion of said fuel burner apparatus, and a predetermined pressure regulation setting; and
fuel delivery apparatus coupled to said pressure regulator apparatus inlet portion and operative to deliver thereto a selectively variable one of (1) a first fuel, from a source thereof, at a pressure greater than said predetermined pressure regulation setting, and (2) a second fuel at a pressure lower than said predetermined pressure regulation setting,
said fuel delivery apparatus including a fuel supply line communicated with said inlet portion of said fuel burner apparatus and through which one of said first and second fuels may be flowed, and first and second electromechanical two position, two-way valves connected in series in said fuel supply line in opposite normal flow orientations,
said pressure regulator apparatus regulating the pressure of fuel discharged from its outlet portion only with respect to said first fuel, and
said pressure regulator apparatus and said fuel delivery apparatus being coupled in a manner precluding said pressure regulation setting from being affected by which of said first and second fuels is being delivered to said pressure regulator apparatus.
2. The fuel-fired heating appliance of claim 1 wherein:
said fuel burner apparatus is of a non-aspirating type, and
said fuel-fired heating appliance further comprises a blower operative to supply combustion air to said fuel burner apparatus.
3. The fuel-fired heating appliance of claim 1 wherein:
said fuel-fired heating appliance is a boiler.
4. The fuel-fired heating appliance of claim 1 wherein:
said first fuel is natural gas, and
said second fuel is propane.
5. The fuel-fired heating appliance of claim 1 wherein:
said fuel delivery apparatus further includes a pressure regulator operative to reduce the pressure of the second fuel when it is being flowed to said fuel delivery apparatus.
6. The fuel-fired heating appliance of claim 1 wherein:
said fuel burner apparatus comprises a plurality of fuel burners, and
said pressure regulator apparatus comprises a plurality of pressure regulators operatively coupled to said plurality of fuel burners.
7. A fuel-fired heating appliance comprising:
a fuel burner having an inlet orifice;
a fuel delivery system for alternately supplying first and second fuels having different wobbe indexes to said inlet orifice at different pressures related to said different Wobbe indexes in a predetermined manner such that the firing rate of said fuel burner remains substantially the same, without changing said inlet orifice, regardless of which one of said first and second fuels is being supplied to said fuel burner, said fuel delivery system including:
a fuel supply line communicated with said inlet orifice and through which one of said first and second fuels may be flowed,
first and second electromechanical two position, two-way valves connected in series in said fuel supply line in opposite normal flow orientations,
a first pressure regulator through which both of said first and second fuels must flow to reach said fuel burner, and
a second pressure regulator through which only the higher Wobbe index fuel must flow to reach said fuel burner.
8. The fuel-fired heating appliance of claim 7 wherein:
said fuel-fired heating appliance is a fuel-fired boiler.
9. The fuel-fired heating appliance of claim 7 wherein:
said fuel burner is a non-aspirating type burner, and
said fuel-fired heating appliance further comprises a blower operative to supply combustion air to said fuel burner.
10. The fuel-fired heating appliance of claim 7 wherein:
the pressure regulation setting of said first pressure regulator is higher than the pressure regulation setting of said second pressure regulator.
11. A fuel-fired heating appliance comprising:
non-aspirating type fuel burner apparatus having an orificed fuel inlet portion;
blower apparatus for supplying combustion air to said fuel burner apparatus;
a main fuel supply line structure coupled to said orificed fuel inlet portion;
first pressure regulator apparatus connected in said main fuel line structure and having an inlet portion and a first pressure regulation setting;
a first branch fuel supply line structure, coupled to said inlet portion of said first pressure regulator apparatus for receiving a pressurized first fuel;
a second branch fuel supply line structure, coupled to said inlet portion of said first pressure regulator apparatus, for receiving a pressurized second fuel having a wobbe index higher than that of said first fuel;
valve apparatus operable to permit flow of only a selectively variable one of said first and second fuels to said inlet portion of said first pressure regulator apparatus and thus to said orificed fuel inlet portion of said fuel burner apparatus, said valve apparatus including first and second electromechanical valves connected in series in said first branch fuel supply line structure in opposite normal flow orientations; and
second pressure regulator apparatus connected in said second branch fuel supply line structure and having a second pressure regulation setting,
said first and second pressure regulation settings being related to one another in a predetermined manner such that, without altering said orificed fuel inlet portion of said burner apparatus, the firing rate of said burner apparatus will remain essentially constant regardless of which of said first and second fuels is being supplied thereto.
12. The fuel-fired heating appliance of claim 11 wherein:
said fuel-fired heating appliance is a dual fuel boiler.
13. The fuel-fired heating apparatus of claim 11 wherein:
said burner apparatus comprises a plurality of non-aspirating type fuel burners each having an orificed inlet.
14. The fuel-fired heating appliance of claim 11 wherein:
said first pressure regulation apparatus comprises a plurality of pressure regulator devices.
15. The fuel-fired heating appliance of claim 11 wherein:
said first pressure regulation setting is greater than said second pressure regulation setting.
16. A fuel-fired heating appliance comprising:
fuel burner apparatus having an inlet portion; and
fuel delivery apparatus operative to deliver to said fuel burner apparatus a selectively variable one of a first fuel from a source thereof, and a second fuel from a source thereof,
said fuel delivery apparatus including a main fuel supply line connected to said inlet portion of said fuel burner apparatus, a first fuel supply branch line connected to said main fuel supply line and connectable to said first source, first valve apparatus connected in said first fuel supply branch line and being openable and closable to selectively permit and preclude flow of said first fuel therethrough, said first valve apparatus including first and second electromechanical two position, two-way valves connected in series, and in opposite normal flow orientations, in said first fuel supply branch line, a second fuel supply branch line connected to said main fuel supply line and connectable to said second source, and second valve apparatus connected in said second fuel supply branch line and being openable and closable to selectively permit and preclude flow of said second fuel therethrough.
17. The fuel-fired heating appliance of claim 16 wherein:
said fuel-fired heating appliance is a dual fuel boiler.
18. The fuel-fired heating appliance of claim 16 wherein:
said first fuel is natural gas, and said second fuel is propane.
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/324,430 US20070154856A1 (en) | 2006-01-03 | 2006-01-03 | Dual fuel boiler with backflow-preventing valve arrangement |
CA002538784A CA2538784C (en) | 2006-01-03 | 2006-03-07 | Dual fuel boiler with backflow-preventing valve arrangement |
AU2006201139A AU2006201139B2 (en) | 2006-01-03 | 2006-03-20 | Dual fuel boiler with backflow-preventing valve arrangement |
NZ546094A NZ546094A (en) | 2006-01-03 | 2006-03-24 | Dual fuel boiler with backflow-preventing valve arrangement |
MXPA06003629A MXPA06003629A (en) | 2006-01-03 | 2006-03-30 | Dual fuel boiler with backflow-preventing valve arrangement. |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/324,430 US20070154856A1 (en) | 2006-01-03 | 2006-01-03 | Dual fuel boiler with backflow-preventing valve arrangement |
Publications (1)
Publication Number | Publication Date |
---|---|
US20070154856A1 true US20070154856A1 (en) | 2007-07-05 |
Family
ID=38224868
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/324,430 Abandoned US20070154856A1 (en) | 2006-01-03 | 2006-01-03 | Dual fuel boiler with backflow-preventing valve arrangement |
Country Status (5)
Country | Link |
---|---|
US (1) | US20070154856A1 (en) |
AU (1) | AU2006201139B2 (en) |
CA (1) | CA2538784C (en) |
MX (1) | MXPA06003629A (en) |
NZ (1) | NZ546094A (en) |
Cited By (31)
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---|---|---|---|---|
US20080149872A1 (en) * | 2006-12-22 | 2008-06-26 | David Deng | Valve assemblies for heating devices |
US20080223465A1 (en) * | 2007-03-14 | 2008-09-18 | David Deng | Fuel selection valve assemblies |
US20080227045A1 (en) * | 2007-03-15 | 2008-09-18 | David Deng | Fuel selectable heating devices |
US20100037884A1 (en) * | 2006-05-17 | 2010-02-18 | David Deng | Dual fuel heater |
US20100170503A1 (en) * | 2006-05-17 | 2010-07-08 | David Deng | Heater configured to operate with a first or second fuel |
US8011920B2 (en) | 2006-12-22 | 2011-09-06 | David Deng | Valve assemblies for heating devices |
US8317511B2 (en) | 2006-12-22 | 2012-11-27 | Continental Appliances, Inc. | Control valves for heaters and fireplace devices |
US8465277B2 (en) | 2009-06-29 | 2013-06-18 | David Deng | Heat engine with nozzle |
US8516878B2 (en) | 2006-05-17 | 2013-08-27 | Continental Appliances, Inc. | Dual fuel heater |
US20140072920A1 (en) * | 2012-07-04 | 2014-03-13 | Continental Appliances, Inc. D.B.A. Procom | Dual fuel heater with selector valve |
WO2014042837A1 (en) * | 2012-09-13 | 2014-03-20 | David Deng | Dual fuel heating apparatus |
US8752541B2 (en) | 2010-06-07 | 2014-06-17 | David Deng | Heating system |
US8915239B2 (en) | 2011-10-20 | 2014-12-23 | David Deng | Dual fuel heater with selector valve |
US8985094B2 (en) | 2011-04-08 | 2015-03-24 | David Deng | Heating system |
US9022064B2 (en) | 2012-05-10 | 2015-05-05 | David Deng | Dual fuel control device with auxiliary backline pressure regulator |
US9091431B2 (en) | 2012-09-13 | 2015-07-28 | David Deng | Dual fuel valve with air shutter adjustment |
US9170016B2 (en) | 2012-08-22 | 2015-10-27 | David Deng | Dual fuel heater with selector valve |
US9175848B2 (en) | 2011-12-05 | 2015-11-03 | David Deng | Dual fuel heater with selector valve |
US9200802B2 (en) | 2011-04-08 | 2015-12-01 | David Deng | Dual fuel heater with selector valve |
US20150368921A1 (en) * | 2014-06-20 | 2015-12-24 | Pentair Water Pool And Spa, Inc. | Hybrid Heater |
US9222670B2 (en) | 2010-12-09 | 2015-12-29 | David Deng | Heating system with pressure regulator |
US9423123B2 (en) | 2013-03-02 | 2016-08-23 | David Deng | Safety pressure switch |
US9739389B2 (en) | 2011-04-08 | 2017-08-22 | David Deng | Heating system |
US9752779B2 (en) | 2013-03-02 | 2017-09-05 | David Deng | Heating assembly |
US9829195B2 (en) | 2009-12-14 | 2017-11-28 | David Deng | Dual fuel heating source with nozzle |
US10073071B2 (en) | 2010-06-07 | 2018-09-11 | David Deng | Heating system |
US10222057B2 (en) | 2011-04-08 | 2019-03-05 | David Deng | Dual fuel heater with selector valve |
US10240789B2 (en) | 2014-05-16 | 2019-03-26 | David Deng | Dual fuel heating assembly with reset switch |
USD859618S1 (en) | 2017-09-15 | 2019-09-10 | Pentair Water Pool And Spa, Inc. | Heating apparatus clip |
US10429074B2 (en) | 2014-05-16 | 2019-10-01 | David Deng | Dual fuel heating assembly with selector switch |
US20230062854A1 (en) * | 2021-08-25 | 2023-03-02 | Grand Mate Co., Ltd. | Gas appliance and a control method thereof |
Citations (28)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2389413A (en) * | 1941-09-26 | 1945-11-20 | Carlton Frank | Method of preventing backflow or back-siphonage in pressure systems |
US2646816A (en) * | 1944-10-05 | 1953-07-28 | Donald G Griswold | Backflow prevention device |
US3001541A (en) * | 1957-03-18 | 1961-09-26 | Weatherhead Co | Automatic regulator assembly |
US3556947A (en) * | 1967-11-09 | 1971-01-19 | Koppers Co Inc | Method for regulating the heating of coke ovens |
US3906987A (en) * | 1974-03-13 | 1975-09-23 | Watts Regulator Co | Swing open cross-connection valve |
USRE29481E (en) * | 1971-02-01 | 1977-11-29 | Fluid Devices, Ltd. | Multi-way directional fluid flow control valve arrangement |
US4138725A (en) * | 1976-07-30 | 1979-02-06 | Kawasaki Jukogyo Kabushiki Kaisha | Automatic fuel combustion control method and system |
US4217921A (en) * | 1978-06-16 | 1980-08-19 | Zurn Industries, Inc. | Back flow preventer valve |
US4231387A (en) * | 1979-01-11 | 1980-11-04 | Chas. M. Bailey Co., Inc. | Backflow preventing valve |
US4232704A (en) * | 1978-03-28 | 1980-11-11 | Amtrol Inc. | In line back flow preventer |
US4359284A (en) * | 1981-03-17 | 1982-11-16 | Honeywell Inc. | Method and apparatus for determining the Wobbe index of gaseous fuels |
US4489746A (en) * | 1982-05-28 | 1984-12-25 | Mueller Co. | Backflow preventer apparatus |
US4492207A (en) * | 1981-02-27 | 1985-01-08 | Petrosystems International, Inc. | Dual fuel system |
US4523607A (en) * | 1982-05-28 | 1985-06-18 | Mueller Co. | Backflow preventer apparatus |
US4559785A (en) * | 1985-01-09 | 1985-12-24 | Phillips Petroleum Company | Boiler control |
US5254092A (en) * | 1992-09-15 | 1993-10-19 | American Medical Systems, Inc. | Fluid flow check valve |
US5709240A (en) * | 1995-08-11 | 1998-01-20 | Grinnell Corporation | Check valve and backflow preventer |
US5816792A (en) * | 1997-12-22 | 1998-10-06 | Roberts-Gordon, Inc. | Alternate gas fuel burning system |
US5947152A (en) * | 1995-08-11 | 1999-09-07 | Grinnell Corporation | Check valve and backflow preventer |
US5999888A (en) * | 1997-06-09 | 1999-12-07 | Alternate Energy Corporation | Automated control system for managing multiple energy sources |
US6135792A (en) * | 1998-12-28 | 2000-10-24 | Hon Hai Precision Ind. Co., Ltd. | Electrical card connector |
US20020096212A1 (en) * | 2001-01-09 | 2002-07-25 | Akira Yamada | High pressure gas supplying system |
US6520206B2 (en) * | 2000-09-01 | 2003-02-18 | Aisan Kogyo Kabushiki Kaisha | Bi-directional pilot type electromagnetic valves |
US6591817B2 (en) * | 2001-03-21 | 2003-07-15 | Motorola, Inc. | Dual fuel method and system |
US20030217555A1 (en) * | 2002-05-21 | 2003-11-27 | Gerhold Bruce W. | Dual fuel power generation system |
US20040106078A1 (en) * | 2001-03-23 | 2004-06-03 | Peter Goebel | Method and device for adjusting air ratio |
US6883344B2 (en) * | 2002-01-24 | 2005-04-26 | Chujun Gu | Air-conditioner with both cooling and warming functions |
US6904873B1 (en) * | 2004-01-20 | 2005-06-14 | Rheem Manufacturing Company | Dual fuel boiler |
-
2006
- 2006-01-03 US US11/324,430 patent/US20070154856A1/en not_active Abandoned
- 2006-03-07 CA CA002538784A patent/CA2538784C/en not_active Expired - Fee Related
- 2006-03-20 AU AU2006201139A patent/AU2006201139B2/en not_active Ceased
- 2006-03-24 NZ NZ546094A patent/NZ546094A/en unknown
- 2006-03-30 MX MXPA06003629A patent/MXPA06003629A/en not_active Application Discontinuation
Patent Citations (29)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2389413A (en) * | 1941-09-26 | 1945-11-20 | Carlton Frank | Method of preventing backflow or back-siphonage in pressure systems |
US2646816A (en) * | 1944-10-05 | 1953-07-28 | Donald G Griswold | Backflow prevention device |
US3001541A (en) * | 1957-03-18 | 1961-09-26 | Weatherhead Co | Automatic regulator assembly |
US3556947A (en) * | 1967-11-09 | 1971-01-19 | Koppers Co Inc | Method for regulating the heating of coke ovens |
USRE29481E (en) * | 1971-02-01 | 1977-11-29 | Fluid Devices, Ltd. | Multi-way directional fluid flow control valve arrangement |
US3906987A (en) * | 1974-03-13 | 1975-09-23 | Watts Regulator Co | Swing open cross-connection valve |
US4138725A (en) * | 1976-07-30 | 1979-02-06 | Kawasaki Jukogyo Kabushiki Kaisha | Automatic fuel combustion control method and system |
US4232704A (en) * | 1978-03-28 | 1980-11-11 | Amtrol Inc. | In line back flow preventer |
US4217921A (en) * | 1978-06-16 | 1980-08-19 | Zurn Industries, Inc. | Back flow preventer valve |
US4231387A (en) * | 1979-01-11 | 1980-11-04 | Chas. M. Bailey Co., Inc. | Backflow preventing valve |
US4492207A (en) * | 1981-02-27 | 1985-01-08 | Petrosystems International, Inc. | Dual fuel system |
US4359284A (en) * | 1981-03-17 | 1982-11-16 | Honeywell Inc. | Method and apparatus for determining the Wobbe index of gaseous fuels |
US4489746A (en) * | 1982-05-28 | 1984-12-25 | Mueller Co. | Backflow preventer apparatus |
US4523607A (en) * | 1982-05-28 | 1985-06-18 | Mueller Co. | Backflow preventer apparatus |
US4559785A (en) * | 1985-01-09 | 1985-12-24 | Phillips Petroleum Company | Boiler control |
US5254092A (en) * | 1992-09-15 | 1993-10-19 | American Medical Systems, Inc. | Fluid flow check valve |
US5709240A (en) * | 1995-08-11 | 1998-01-20 | Grinnell Corporation | Check valve and backflow preventer |
US5947152A (en) * | 1995-08-11 | 1999-09-07 | Grinnell Corporation | Check valve and backflow preventer |
US5999888A (en) * | 1997-06-09 | 1999-12-07 | Alternate Energy Corporation | Automated control system for managing multiple energy sources |
US5816792A (en) * | 1997-12-22 | 1998-10-06 | Roberts-Gordon, Inc. | Alternate gas fuel burning system |
US6135792A (en) * | 1998-12-28 | 2000-10-24 | Hon Hai Precision Ind. Co., Ltd. | Electrical card connector |
US6520206B2 (en) * | 2000-09-01 | 2003-02-18 | Aisan Kogyo Kabushiki Kaisha | Bi-directional pilot type electromagnetic valves |
US20020096212A1 (en) * | 2001-01-09 | 2002-07-25 | Akira Yamada | High pressure gas supplying system |
US6591817B2 (en) * | 2001-03-21 | 2003-07-15 | Motorola, Inc. | Dual fuel method and system |
US20040106078A1 (en) * | 2001-03-23 | 2004-06-03 | Peter Goebel | Method and device for adjusting air ratio |
US6883344B2 (en) * | 2002-01-24 | 2005-04-26 | Chujun Gu | Air-conditioner with both cooling and warming functions |
US20030217555A1 (en) * | 2002-05-21 | 2003-11-27 | Gerhold Bruce W. | Dual fuel power generation system |
US6779333B2 (en) * | 2002-05-21 | 2004-08-24 | Conocophillips Company | Dual fuel power generation system |
US6904873B1 (en) * | 2004-01-20 | 2005-06-14 | Rheem Manufacturing Company | Dual fuel boiler |
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US9416977B2 (en) | 2006-05-17 | 2016-08-16 | Procom Heating, Inc. | Heater configured to operate with a first or second fuel |
US8281781B2 (en) | 2006-05-17 | 2012-10-09 | Continental Appliances, Inc. | Dual fuel heater |
US8235708B2 (en) | 2006-05-17 | 2012-08-07 | Continental Appliances, Inc. | Heater configured to operate with a first or second fuel |
US8568136B2 (en) | 2006-05-17 | 2013-10-29 | Procom Heating, Inc. | Heater configured to operate with a first or second fuel |
US20100170503A1 (en) * | 2006-05-17 | 2010-07-08 | David Deng | Heater configured to operate with a first or second fuel |
US7967006B2 (en) | 2006-05-17 | 2011-06-28 | David Deng | Dual fuel heater |
US7967007B2 (en) | 2006-05-17 | 2011-06-28 | David Deng | Heater configured to operate with a first or second fuel |
US8516878B2 (en) | 2006-05-17 | 2013-08-27 | Continental Appliances, Inc. | Dual fuel heater |
US20100037884A1 (en) * | 2006-05-17 | 2010-02-18 | David Deng | Dual fuel heater |
US10066838B2 (en) | 2006-05-30 | 2018-09-04 | David Deng | Dual fuel heating system |
US9140457B2 (en) | 2006-05-30 | 2015-09-22 | David Deng | Dual fuel heating system and air shutter |
US9328922B2 (en) | 2006-12-22 | 2016-05-03 | Procom Heating, Inc. | Valve assemblies for heating devices |
US8297968B2 (en) * | 2006-12-22 | 2012-10-30 | Continental Appliances, Inc. | Pilot assemblies for heating devices |
US8317511B2 (en) | 2006-12-22 | 2012-11-27 | Continental Appliances, Inc. | Control valves for heaters and fireplace devices |
US20080149872A1 (en) * | 2006-12-22 | 2008-06-26 | David Deng | Valve assemblies for heating devices |
US8545216B2 (en) | 2006-12-22 | 2013-10-01 | Continental Appliances, Inc. | Valve assemblies for heating devices |
US8011920B2 (en) | 2006-12-22 | 2011-09-06 | David Deng | Valve assemblies for heating devices |
US8764436B2 (en) | 2006-12-22 | 2014-07-01 | Procom Heating, Inc. | Valve assemblies for heating devices |
US9581329B2 (en) | 2007-03-14 | 2017-02-28 | Procom Heating, Inc. | Gas-fueled heater |
US8241034B2 (en) * | 2007-03-14 | 2012-08-14 | Continental Appliances Inc. | Fuel selection valve assemblies |
US9200801B2 (en) | 2007-03-14 | 2015-12-01 | Procom Heating, Inc. | Fuel selection valve assemblies |
US20080223465A1 (en) * | 2007-03-14 | 2008-09-18 | David Deng | Fuel selection valve assemblies |
US8152515B2 (en) * | 2007-03-15 | 2012-04-10 | Continental Appliances Inc | Fuel selectable heating devices |
US20080227045A1 (en) * | 2007-03-15 | 2008-09-18 | David Deng | Fuel selectable heating devices |
US8517718B2 (en) | 2009-06-29 | 2013-08-27 | David Deng | Dual fuel heating source |
US8465277B2 (en) | 2009-06-29 | 2013-06-18 | David Deng | Heat engine with nozzle |
US8757202B2 (en) | 2009-06-29 | 2014-06-24 | David Deng | Dual fuel heating source |
US8757139B2 (en) | 2009-06-29 | 2014-06-24 | David Deng | Dual fuel heating system and air shutter |
US9829195B2 (en) | 2009-12-14 | 2017-11-28 | David Deng | Dual fuel heating source with nozzle |
US9021859B2 (en) | 2010-06-07 | 2015-05-05 | David Deng | Heating system |
US8851065B2 (en) | 2010-06-07 | 2014-10-07 | David Deng | Dual fuel heating system with pressure sensitive nozzle |
US10073071B2 (en) | 2010-06-07 | 2018-09-11 | David Deng | Heating system |
US8752541B2 (en) | 2010-06-07 | 2014-06-17 | David Deng | Heating system |
US9222670B2 (en) | 2010-12-09 | 2015-12-29 | David Deng | Heating system with pressure regulator |
US9739389B2 (en) | 2011-04-08 | 2017-08-22 | David Deng | Heating system |
US9200802B2 (en) | 2011-04-08 | 2015-12-01 | David Deng | Dual fuel heater with selector valve |
US10222057B2 (en) | 2011-04-08 | 2019-03-05 | David Deng | Dual fuel heater with selector valve |
US8985094B2 (en) | 2011-04-08 | 2015-03-24 | David Deng | Heating system |
US9752782B2 (en) | 2011-10-20 | 2017-09-05 | David Deng | Dual fuel heater with selector valve |
US8915239B2 (en) | 2011-10-20 | 2014-12-23 | David Deng | Dual fuel heater with selector valve |
US9175848B2 (en) | 2011-12-05 | 2015-11-03 | David Deng | Dual fuel heater with selector valve |
US9022064B2 (en) | 2012-05-10 | 2015-05-05 | David Deng | Dual fuel control device with auxiliary backline pressure regulator |
US9523497B2 (en) * | 2012-07-04 | 2016-12-20 | David Deng | Dual fuel heater with selector valve |
US20140072920A1 (en) * | 2012-07-04 | 2014-03-13 | Continental Appliances, Inc. D.B.A. Procom | Dual fuel heater with selector valve |
US9170016B2 (en) | 2012-08-22 | 2015-10-27 | David Deng | Dual fuel heater with selector valve |
WO2014042837A1 (en) * | 2012-09-13 | 2014-03-20 | David Deng | Dual fuel heating apparatus |
US9091431B2 (en) | 2012-09-13 | 2015-07-28 | David Deng | Dual fuel valve with air shutter adjustment |
US9423123B2 (en) | 2013-03-02 | 2016-08-23 | David Deng | Safety pressure switch |
US9441833B2 (en) | 2013-03-02 | 2016-09-13 | David Deng | Heating assembly |
US9752779B2 (en) | 2013-03-02 | 2017-09-05 | David Deng | Heating assembly |
US20170074512A1 (en) * | 2013-03-02 | 2017-03-16 | David Deng | Safety pressure switch |
US9518732B2 (en) | 2013-03-02 | 2016-12-13 | David Deng | Heating assembly |
US10240789B2 (en) | 2014-05-16 | 2019-03-26 | David Deng | Dual fuel heating assembly with reset switch |
US10429074B2 (en) | 2014-05-16 | 2019-10-01 | David Deng | Dual fuel heating assembly with selector switch |
US20150368921A1 (en) * | 2014-06-20 | 2015-12-24 | Pentair Water Pool And Spa, Inc. | Hybrid Heater |
US9732536B2 (en) * | 2014-06-20 | 2017-08-15 | Pentair Water Pool And Spa, Inc. | Hybrid heater |
US10400466B2 (en) | 2014-06-20 | 2019-09-03 | Pentair Water Pool And Spa, Inc. | Hybrid heater |
US11142923B2 (en) | 2014-06-20 | 2021-10-12 | Pentair Water Pool And Spa, Inc. | Hybrid heater |
US11686118B2 (en) | 2014-06-20 | 2023-06-27 | Pentair Water Pool And Spa, Inc. | Hybrid heater |
USD859618S1 (en) | 2017-09-15 | 2019-09-10 | Pentair Water Pool And Spa, Inc. | Heating apparatus clip |
US20230062854A1 (en) * | 2021-08-25 | 2023-03-02 | Grand Mate Co., Ltd. | Gas appliance and a control method thereof |
Also Published As
Publication number | Publication date |
---|---|
AU2006201139A1 (en) | 2007-07-19 |
NZ546094A (en) | 2007-08-31 |
CA2538784A1 (en) | 2007-07-03 |
CA2538784C (en) | 2009-09-08 |
AU2006201139B2 (en) | 2008-01-10 |
MXPA06003629A (en) | 2007-07-02 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: RHEEM MANUFACTURING COMPANY, NEW YORK Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HALLIT, RAYMOND;GLASS, ROBERT S.;ASHTON, LARRY J.;REEL/FRAME:017130/0802 Effective date: 20051216 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |