US20140212821A1 - Ignition system for flame emitting apparatus - Google Patents
Ignition system for flame emitting apparatus Download PDFInfo
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- US20140212821A1 US20140212821A1 US14/229,512 US201414229512A US2014212821A1 US 20140212821 A1 US20140212821 A1 US 20140212821A1 US 201414229512 A US201414229512 A US 201414229512A US 2014212821 A1 US2014212821 A1 US 2014212821A1
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- Prior art keywords
- temperature
- flame
- controller
- burner
- temperature sensor
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N5/00—Systems for controlling combustion
- F23N5/24—Preventing development of abnormal or undesired conditions, i.e. safety arrangements
- F23N5/242—Preventing development of abnormal or undesired conditions, i.e. safety arrangements using electronic means
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N5/00—Systems for controlling combustion
- F23N5/02—Systems for controlling combustion using devices responsive to thermal changes or to thermal expansion of a medium
- F23N5/10—Systems for controlling combustion using devices responsive to thermal changes or to thermal expansion of a medium using thermocouples
- F23N5/102—Systems for controlling combustion using devices responsive to thermal changes or to thermal expansion of a medium using thermocouples using electronic means
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N5/00—Systems for controlling combustion
- F23N5/20—Systems for controlling combustion with a time programme acting through electrical means, e.g. using time-delay relays
- F23N5/203—Systems for controlling combustion with a time programme acting through electrical means, e.g. using time-delay relays using electronic means
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24C—DOMESTIC STOVES OR RANGES ; DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION
- F24C3/00—Stoves or ranges for gaseous fuels
- F24C3/08—Arrangement or mounting of burners
- F24C3/085—Arrangement or mounting of burners on ranges
- F24C3/087—Arrangement or mounting of burners on ranges in baking ovens
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24C—DOMESTIC STOVES OR RANGES ; DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION
- F24C3/00—Stoves or ranges for gaseous fuels
- F24C3/10—Arrangement or mounting of ignition devices
- F24C3/103—Arrangement or mounting of ignition devices of electric ignition devices
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N2227/00—Ignition or checking
- F23N2227/02—Starting or ignition cycles
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N2229/00—Flame sensors
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N2241/00—Applications
- F23N2241/08—Household apparatus
Definitions
- the present invention generally relates to an ignition system for a flame-emitting apparatus and more particularly to an ignition system for a cooking apparatus such as a rotisserie oven that confirms the presence of a flame.
- a flame is ignited from a fuel source such as propane or natural gas.
- a fuel source such as propane or natural gas.
- One type of cooking apparatus is a rotisserie oven.
- Rotisserie ovens are well known in the art.
- the ovens typically have a carousel mechanism or rotating member that rotates food items during cooking.
- the food items are supported by skewers that are removably connected to the rotating member.
- the rotisserie oven typically has a burner in communication with a fuel source.
- the ovens further have an ignition system used to initially ignite the burner.
- the flame-emitting apparatuses may have a flame detecting system as part of an ignition system or a separate system that may use a flame sensor to detect the presence of a flame. The flame sensor can become fouled and rendered inoperable.
- Flame-emitting apparatuses may also use flame rectification systems that pass a current through a flame to detect a flame and other systems may employ optical methods in detecting a flame. Because of limitations in the structure and methods of such prior art systems, false readings can occur or the system can experience the inability to obtain a reading to confirm the presence of a flame.
- the present invention provides a system for detecting a presence of a flame in a flame-emitting apparatus.
- the system may be part of an ignition system for the flame-emitting apparatus that confirms the presence of a flame.
- the ignition system is used in a cooking apparatus.
- a system detects the presence of a flame in a flame-emitting apparatus.
- the flame-emitting apparatus has a burner and the burner is in communication with a fuel source. The burner emits a flame when the burner is fully ignited.
- the system has a temperature sensor configured to be positioned in the apparatus and is adjacent the burner wherein the sensor is configured to be positioned within the flame of the burner.
- a controller is operably connected to the temperature sensor and the burner wherein the controller receives temperature data from the temperature sensor. The controller determines whether a flame is present based on the temperature data received, and when determining that a flame is not present, the controller is configured to interrupt the supply of fuel to the burner.
- a rotisserie oven has a housing defining a cavity.
- a rotating member is positioned within the cavity and is configured to support and rotate a plurality of food items within the cavity.
- a burner is positioned within the housing and has an inlet configured to be in fluid communication with a fuel source. The burner further has an outlet allowing a flame member to extend therefrom into the cavity as a product of combusting fuel supplied to the burner.
- An ignition system is operably coupled to the housing and has an igniter positioned adjacent the burner.
- the system further has a temperature sensor positioned adjacent the burner wherein the sensor is positioned to be within an outer periphery of the flame.
- the system has an ignition controller operably coupled to the igniter and thermocouple and configured to control the delivery of fuel to the burner.
- the controller of the ignition system utilizes an algorithm to detect temperature changes within a predetermined range and controls the delivery of fuel in response thereto.
- a cooking apparatus has a housing defining an interior cavity configured for cooking a food item.
- a support member is configured for supporting the food item.
- a burner is configured to burn a fuel to emit a cooking flame to heat the food item.
- a temperature sensor has a portion positioned proximate the burner to detect a temperature of the cooking flame.
- a controller is in communication with the temperature sensor, and the controller is configured for analyzing output from the temperature sensor to determine if the cooking flame is present, based on a change in temperature detected by the temperature sensor.
- a cooking apparatus has a housing defining an interior cavity configured for cooking a food item.
- a support member is configured for supporting the food item.
- a burner has an aperture, and the burner is configured to burn a fuel to emit a cooking flame from the aperture to heat the food item when the burner is ignited.
- a temperature sensor has a portion positioned proximate the aperture to detect a temperature of the cooking flame, wherein the portion of the temperature sensor is configured to be positioned within the cooking flame when the burner is ignited.
- a control system is in communication with the temperature sensor, and the control system is configured for analyzing output from the temperature sensor to determine if the cooking flame is present.
- FIG. 1 is a perspective view of a flame-emitting apparatus in the form of a cooking apparatus such as a rotisserie oven utilizing an ignition system according to the present invention
- FIG. 2 is a front elevation view of the cooking apparatus utilizing the ignition system according to the present invention
- FIG. 3 is a side perspective view of the cooking apparatus showing additional control components associated with the apparatus;
- FIG. 4 is a partial perspective view of a temperature sensor of the ignition system and a burner of the rotisserie oven;
- FIG. 5 is a schematic view of a thermocouple used in the ignition system of the present invention including a partial enlarged portion;
- FIG. 6 is a flow chart disclosing operational features of the ignition system according to the present invention.
- FIG. 7 is a flow chart disclosing an exemplary embodiment of certain operational features of the ignition system according to the present invention.
- FIGS. 8-10 are flow charts disclosing another exemplary embodiment of certain operational features of the ignition system according to the present invention.
- FIGS. 11 and 12 are flow charts disclosing safety interlocks associated with the embodiment of the ignition system of FIGS. 8-10 ;
- FIG. 13 is a flow chart of an igniter selection subroutine associated with the embodiment of the ignition system of FIGS. 8-10 ;
- FIG. 14 is a perspective view of a gas lighting lamp utilizing the ignition system of the present invention.
- FIG. 15 is a perspective view of a heating lamp utilizing the ignition system of the present invention.
- FIG. 16 is a schematic diagram illustrating various control components according to an embodiment of the present invention.
- the present invention relates generally to a variety of flame-emitting apparatuses including cooking apparatuses.
- a flame-emitting apparatus typically has some form of burner connected to a fuel source.
- the apparatus also may have an ignition system for initially igniting the fuel supplied to the burner.
- the present invention includes structures and methods that confirm the presence of a flame upon igniting the burner to assure proper operation. Such structures and methods may be an integral part of the ignition system or operably interact with the ignition system, and may be generally referred to as flame detecting systems, flame confirmation systems, flame proving systems, or flame rectification systems.
- the present invention applies to a wide variety of apparatuses including any type of cooking cavities as well as outdoor cooking devices, gas lamps used for lighting purposes, outdoor heat lamps, outdoor decorative appliances, hot water heaters, boilers or other devices connected to a fuel source wherein the device emits a flame.
- the device is a rotisserie oven and a detailed discussion is provided regarding the rotisserie oven. It is understood that the device could also be other types of cooking devices that have a burner positioned either in a cooking cavity or adjacent to the cooking cavity as an external heat source. It is further understood that the structures and methods described herein in detail apply to and can be utilized in any type of flame-emitting apparatus. The invention will now be described as utilized in one exemplary embodiment of a rotisserie oven.
- FIG. 1 discloses a rotisserie oven that can incorporate the present invention, the oven generally designated with the reference numeral 10 .
- FIG. 1 illustrates the oven 10 that is configured to cook a plurality of food items.
- the food items may oftentimes be chickens or other types of birds although it is understood that various other food items can be cooked in the oven 10 .
- the oven 10 generally includes a housing 14 , a rotating or rotatable member 16 , and a heating assembly 18 .
- the housing 14 can be of any shape generally known in the art.
- the housing 14 has a plurality of walls defining an interior cavity 20 .
- the interior cavity 20 is generally defined by a top wall, a bottom wall, a rear wall, a front wall and a pair of sidewalls.
- the housing 14 has an access door 22 in the front wall for placing the food item into the housing 14 .
- the rotating member 16 may be in the form of a carousel mechanism and has a plate 24 rotatably mounted on each sidewall of the housing 14 . It is understood the rotating member 16 has a drive mechanism for rotating the rotating member 16 .
- the rotating member 16 includes a plurality of support members or skewers 26 and may be considered a movable skewer assembly. A respective end of each skewer 26 is removably mounted on the plates 24 of the rotating member 16 .
- food items loaded onto the skewers 26 such that at least one skewer 26 extends at least partially through the food item and the skewers 26 are rotated within the housing 14 during cooking.
- the heating assembly 18 is operably associated with the housing 14 and provides a heat source for heating the interior cavity 20 and cooking the food item.
- the heating assembly 18 typically has a heating element that in one exemplary embodiment is a burner 28 that is in fluid communication with a fuel source such as propane or natural gas.
- a fuel source such as propane or natural gas.
- the burner 28 is generally positioned within the cavity 20 and generally at a bottom portion of the housing 14 . It is understood that the burner 28 can be positioned in other areas of the housing 14 .
- the burner 28 is a tubular structure having a proximate end 30 and a distal end 32 .
- the burner 28 has a plurality of apertures 34 along a length of the burner 28 .
- the burner 28 is in fluid communication with a gas supply 36 ( FIG. 3 ) and a gas valve 38 ( FIG. 3 ) is mounted between the proximate end 30 and the gas supply 36 .
- a flame 40 is emitted and extends from the apertures 34 in the burner 28 .
- the flame 40 has an outer zone 41 that defines an outer periphery 42 of the flame 40 and which generally may represent the hottest part of the flame 40 .
- the flame 40 further has a middle zone 44 and an inner zone 46 that has little combustion due to lack of oxygen.
- the rotisserie oven 10 has a master controller 48 ( FIG. 2 ) that controls the heating assembly 16 as well as other operational features of the oven 10 .
- the rotisserie oven 10 further has an ignition system 50 .
- the ignition system 50 generally includes an igniter 52 , a temperature sensor 54 and an ignition controller 56 . It is understood that a power supply, breakers, switches etc. are in operable communication with the ignition controller 56 . It is understood that the ignition controller 56 may be considered a part of the master controller 48 but is otherwise in operable communication with the master controller 48 . As explained in greater detail below, the ignition system 50 may also be considered a flame proving system or flame confirmation system.
- the igniter 52 is positioned generally at the proximate end 30 of the burner 28 and generally at a first aperture 34 of the burner 28 .
- the igniter 52 may include a plurality of igniters 52 .
- the temperature sensor 54 is a highly sensitive thermocouple 54 in an exemplary embodiment.
- the thermocouple 54 is a fast-acting thermal probe capable of reading temperatures in a very fast manner and at extreme temperatures.
- the thermocouple 54 is mounted to the housing 14 and is positioned proximate the distal end 32 of the burner 28 .
- the thermocouple 54 is further positioned slightly above the apertures 34 of the burner 28 . As can be appreciated from FIG.
- thermocouple 54 is positioned such that when the burner 28 is in operation and the flame 40 extends from the aperture 34 , at least a portion of the thermocouple 54 is positioned directly within the flame 40 wherein the thermocouple 54 is positioned within the outer periphery 42 of the flame 40 .
- the thermocouple 54 may extend through a plurality of the flames 40 extending from the burner 28 .
- the igniter 52 and the thermocouple 54 are each operably connected to the ignition controller 56 .
- FIG. 5 discloses the thermocouple 54 in greater detail.
- the thermocouple 54 is designed to sense extreme temperatures as well as rapid temperature changes including increasing temperatures and decreasing temperatures.
- the thermocouple 54 is considered a dual-probe unit having a first sensor 55 and a second sensor 57 .
- the first sensor 55 and second sensor 57 both sense the temperature from the burner 28 .
- the first sensor 55 may be considered to be the main sensor associated with the controller 56 for operation in the pre-ignition, ignition and operation phases.
- the second sensor 57 is a type of witness sensor that senses temperature.
- the multi-sensor design is used in a safety interlock as described below.
- the first sensor 55 and the second sensor 57 are housed within a sheath 59 of the thermocouple 54 and are insulated from one another.
- a powder may be compacted in the sheath 59 at a distal end of the sensors 55 , 57 .
- the sheath 59 may have a cap fastened at the end of the sheath 59 enclosing the sensors.
- the gas valve 38 is opened to supply gas to the burner 28 .
- the igniter 52 is activated to provide a spark, start-up flame or incandescence to light the fuel or gas supplied to the burner 28 . If properly ignited, flames 40 should be present at the proximate end 30 and quickly migrate along the burner 28 to the distal end 32 and extend from each aperture 34 as shown in FIG. 2 .
- the thermocouple 54 will be positioned directly within the flame 40 , and the thermocouple 54 will sense a temperature change from an initial state prior to ignition.
- thermocouple 54 will not sense an appropriate temperature change as a flame will not be present at the burner 28 . Temperature readings from the thermocouple 54 are communicated to the ignition controller 56 wherein the controller 56 recognizes a “flame not detected” condition and sends a signal to shut the gas valve 38 to prevent non-combusted fuel from continuing to be supplied into the oven 10 . Supplying un-burnt fuel into the oven 10 can create a hazard. The ignition sequence can be then be re-initiated after a predetermined amount of time or after suitable troubleshooting is performed if necessary.
- the ignition controller 56 also has software utilizing algorithms to further enhance the operation of the ignition system 50 and confirm the presence of the flame 40 during and after ignition.
- the algorithms are generally used by the system 50 to perform certain steps in sensing whether a rate of temperature change as sensed by the thermocouple 54 is sufficient.
- the system 50 may include a plurality of different starting temperature windows that have a rate of temperature change value assigned to the particular window to aid in properly determining the presence of a flame.
- FIG. 16 illustrates an example embodiment of the master controller 48 and the ignition system 50 .
- the master controller 48 in this example may be a general purpose or specialized computer device, and may include typical computer components, including a processor or processing system 110 (e.g., one or more microprocessors), a memory or memory system 112 , which may include RAM, ROM, storage memory, etc., and an interface or interface system 114 .
- the memory 112 may include software including computer executable instructions for use by the processor 110 , such as an operating system, applications, databases, etc.
- the interface 114 may include various types of interfaces, including input/output interfaces for user input and user-readable output, as well as communication interfaces, such as a modem, LAN interface, cellular or other wireless interface, connection port (USB, Firewire, etc.), or other types of interfaces.
- the master controller 48 may include further components in some embodiments, such as a power supply (e.g., a battery or other power source).
- the master controller 48 is in communication with the ignition controller 56 of the ignition system 50 .
- the ignition controller 56 may include any of the components described above, including a processor 110 , memory 112 , interface 114 , etc. Additionally, as indicated by the broken lines in FIG. 16 , the ignition controller 56 may be considered part of the master controller 48 in one embodiment, and likewise, the master controller 48 may be considered part of the ignition system 50 .
- the ignition controller 56 is in communication with the igniter 52 , the sensor 54 , and the burner 28 in this embodiment, and can transmit to and/or receive signals from the igniter 52 , the sensor 54 , and/or the burner 28 .
- the ignition controller 56 may transmit a signal to activate the igniter 52 or the burner 28 (e.g. the gas valve(s)).
- the ignition controller 56 may receive a signal indicative of the current in the igniter 52 or the temperature data from the sensor 54 .
- the ignition controller 56 may transmit at least some signals received from the igniter 52 , the sensor 54 , and/or the burner 28 to the master controller. Likewise, in this configuration, some of the signals transmitted by the ignition controller 56 to the igniter 52 , the sensor 54 , and/or the burner 28 may be transmitted in response to a signal from the master controller 48 . Further, if the ignition controller 56 is separate from the master controller 48 , the igniter 52 , the sensor 54 , and/or the burner 28 may additionally or alternately be in communication with the master controller 48 , as indicated by the broken-line connectors in FIG. 16 .
- the ignition controller 56 may be in communication with each of the multiple igniters 52 , sensors 54 , and/or burners 28 .
- aspects of the processes, communications, algorithms/routines, calculations, analysis, etc. described herein may take the form of a computer program product stored by one or more computer-readable storage media having computer-readable program code, or instructions, embodied in or on the storage media (e.g., in the memory 112 ).
- the computer-readable storage media may be tangible and/or non-transitory. Any suitable computer readable storage media may be utilized, including hard disks, CD-ROMs, optical storage devices, magnetic storage devices, microchips, and/or any combination thereof. Additionally, signals transmitted as described herein may be transmitted wirelessly or through a wire or other tangible conducting medium.
- FIG. 6 discloses the general operation of one exemplary embodiment of the ignition system 50 utilizing certain algorithms in greater detail for detecting the presence of a flame.
- FIG. 7 discloses more specific examples of the operation of the ignition system 50 .
- the gas valve 38 is opened and gas is supplied to the burner 28 .
- the ignition controller 56 activates the igniter 52 to provide a spark, start-up flame or incandescence to ignite the burner 28 .
- the thermocouple 54 senses an initial temperature immediately following ignition and communicates such reading to the ignition controller 56 .
- the ignition controller 56 determines an initial rate of temperature change from the initial temperature and the temperature sensed immediately following ignition (such temperature will be considered the maximum value the temperature rose to upon this initial temperature change determination, and designated as sensed temperature TS) to determine if such change is sufficient. If a sufficient rate of temperature change is not detected, the system 50 determines that a “flame not detected” condition exists and the burner 28 has failed to ignite. The ignition controller 56 shuts off the gas valve 38 and the ignition process is stopped. After a purge time is completed to allow gas to sufficiently diffuse, the process can be re-initiated a predetermined number of times. If the trials exceed the predetermined number of times, the ignition process terminates and transmits a signal to the alarm output identifying there has been a safety lock.
- thermocouple 54 senses temperatures resulting in a rate of temperature change that the ignition controller 56 recognizes as being sufficient, the ignition controller 56 recognizes that the flame 40 is detected from the burner 28 .
- the ignition controller 56 also has a plurality of different temperature windows covering certain operating temperature ranges of the oven 10 .
- a first window W 1 may be designated for a temperature range equal to or lower than a lowest oven temperature.
- a second window W 2 may be designated for a second temperature range covering an intermediate range.
- Other windows W having other temperature ranges can also be designated including a final window Wn that represents the highest temperature range for the oven 10 .
- the ignition controller 56 recognizes the sensed temperature TS corresponding to the highest temperature sensed at the initial inquiry as described above.
- the ignition controller 56 uses this initial highest sensed temperature TS and determines the corresponding window W to be used to further confirm the presence of a flame.
- each window W corresponds to a temperature range of the oven 10 .
- Each window W has a predetermined acceptable rate of temperature change (or threshold amount) that would indicate a flame is present.
- the ignition controller takes the first sensed temperature TS as discussed above and determines which window W the sensed temperature TS falls into.
- the thermocouple 54 continues to sense temperature values that are communicated to the ignition controller 56 .
- the ignition controller 56 determines the rate of temperature change from the temperatures sensed by the thermocouple 54 and then determines if the rate of temperature change is sufficient for the given temperature window W.
- the system 50 continues to loop through these inquiries wherein the thermocouple 54 continues to sense temperature TS wherein the appropriate window W is determined as well as the rate of temperature change which is compared to the acceptable rate of temperature change for that window W. If the ignition controller 56 does not sense a rate of temperature change that is sufficient for the particular window W, then a flame failure condition is detected by the ignition controller 56 and the controller 56 shuts off the gas valve 38 . It is understood that each window can be programmed for different rates of change.
- the oven 10 continues to operate in normal fashion. It is understood that the ignition system 50 continues to monitor the oven temperature continuously during operation. If, for example, the flame 40 from the burner 28 was unexpectedly extinguished during operation, the thermocouple 54 senses falling temperatures that are communicated to the ignition controller 56 . In response, the ignition controller 56 shuts off the gas valve 38 to interrupt fuel supply to the burner 28 . It is further understood that the master oven controller 48 has a thermostat associated therewith. The master oven controller 48 may also shut-off the burner 28 based on cavity temperature readings associated with the thermostat and according to desired cooking parameters for the particular food items being cooked.
- the burner may be shut-off and then when the cavity temperature falls to a certain level, the master controller 48 sends a signal for the burner 28 to again be ignited.
- the ignition system 50 is used to ignite the burner 28 according the description above.
- FIG. 7 discloses a set of operational parameters for the ignition system 50 in accordance with another exemplary embodiment of the invention.
- the system 50 determines several temperature differences during operation represented by the reference numeral DT 4 , wherein DT 4 represents a temperature difference in any four seconds.
- the gas valve 38 is opened and gas is supplied to the burner 28 .
- the ignition controller 56 activates the igniter 52 to provide a start-up spark, start-up flame or incandescence to the burner 28 and ignite the burner 28 .
- the thermocouple 54 senses temperature and communicates such temperature values to the ignition controller 56 .
- the ignition controller 56 determines whether a temperature difference exists that is greater than or equal to 30° C. as shown in FIG. 7 .
- the ignition controller 56 concludes that the burner 28 failed to ignite. In response, the ignition controller 56 shuts off the gas valve 38 . After a preprogrammed purge time to allow the gas in the oven 10 to sufficiently diffuse, the ignition process can again be initiated as described above.
- the ignition system 50 may also be pre-programmed allowing re-initiation of the ignition process a set number of times. For example, the system 50 can be programmed to allow 5 ignition trials. If the burner 28 is not properly ignited after the fifth try, the operator must perform more detailed troubleshooting prior to re-initiating the ignition process.
- the ignition controller 56 receives sensed temperature data from the thermocouple 54 and determines a temperature difference exists and is greater than or equal to 30° C., a “flame detected” condition is recognized.
- the upper limit of the initial sensed temperature is designated as TS.
- the oven 10 continues to a normal operation condition.
- a plurality of windows W are designated in the ignition controller 56 .
- the system 50 has a first window W 1 , a second window W 2 and a third window W 3 .
- the first window W 1 is set for a temperature range of temperatures equal to or less than 600° C.
- the designated rate of temperature change for the first window W 1 is a change of less than or equal to 5° C.
- the second window W 2 is set for an initial temperature range between 600° C. to 900° C.
- the designated rate of temperature change for the second window W 2 is a change of less than ⁇ 25° C., e.g. a temperature drop of 25° C.
- a third window W 3 is set for an initial temperature range of 900° C. or greater.
- the designated rate of temperature change for the third window W 3 is a change of less than ⁇ 35° C., e.g. a temperature drop of 35° C.
- the ignition controller 56 recognizes the initial sensed temperature value TS corresponding to the highest value sensed at the initial inquiry and determines which window W the temperature TS is assigned.
- the first window W 1 is designated and the ignition controller 56 continues to receive sensed temperature values from the thermocouple 54 .
- the ignition controller 56 determines if a temperature difference exists that is less than or equal to 5° C. If the determined temperature difference is less than or equal to 5° C., a “flame failure” condition is detected wherein the ignition controller 56 shuts off the gas valve. The condition can then be troubleshot and the ignition sequence re-initiated when appropriate. If the determined temperature difference is not less than or equal to 5° C., a normal operation condition is detected wherein ignition controller 56 continues to loop through sensed temperature values received from the thermocouple 54 .
- the ignition controller 56 again determines which window is designated. For example, as temperature rises, the TS value may rise to a value between 600° C. and 900° C. wherein the second window W 2 is designated. The ignition controller 56 then determines if a temperature difference exists that is less than ⁇ 25° C., e.g., whether a temperature drop of 25° C. exists. If this condition does exist, a “flame failure” is detected and the ignition controller 56 shuts off the gas valve. If the determined temperature difference is not less than ⁇ 25° C., e.g., a temperature drop of 25° C.
- a normal operation condition continues to be detected wherein the ignition controller 56 continues to loop through sensed temperature values received from the thermocouple 54 . As the sensed temperature TS continues to rise due to the normal operation of the oven 10 , the ignition controller 56 again determines which window is designated. For example, as temperature rises, the TS value may rise to a value greater than 900° C. wherein the third window W 3 is designated. The ignition controller 56 then determines if a temperature difference exists that is less than ⁇ 35° C., e.g., whether a temperature drop of 35° C. exists. If this condition does exist, a “flame failure” is detected and the ignition controller 56 shuts off the fuel valve.
- the hardware and software/algorithms cooperate to provide a more reliable system to detect a flame appropriately and determine the burner 28 is operating properly.
- the sensed temperature TS may be at a value wherein the certain windows may be skipped in the above described process.
- the oven 10 may have been operating and warm and is then re-ignited after a short period of down time.
- the sensed temperature TS may initially be at a level of over 600° C. wherein the ignition controller 56 proceeds directly to the second window W 2 in the process.
- the process can also start directly in the third window W 3 depending on the value of the sensed temperature TS.
- FIGS. 8-13 disclose further exemplary embodiments regarding the ignition system and additional various algorithms used by the master controller to ignite and monitor operation of the apparatus. Similar elements of prior exemplary embodiments of the ignition system will be designated with like reference numerals.
- the ignition system 50 includes various stages including a pre-ignition phase, an ignition phase and an operating phase. The system further includes safety interlocks and an igniter selection subroutine to be described. It is understood that specific temperatures, temperature ranges and temperature changes are designated for the exemplary embodiment described and can be altered without departing from the invention.
- the controller associated with the ignition system 50 analyzes output from the temperature sensor to determine if the cooking flame is present. In one exemplary embodiment, the analysis is based on a change in temperature detected by the temperature sensor.
- the ignition system 50 may be employed in a rotisserie oven 10 in an exemplary embodiment, but can also be used in other cooking apparatuses or other types of flame-emitting apparatuses.
- a pre-ignition phase is set in the apparatus 10 prior to the ignition phase.
- certain settings associated with the controller 56 are initiated including a timer associated with the controller 56 being initiated to be set at “zero.” The timer is relied upon throughout the different phases of operation of the ignition system 50 and apparatus 10 .
- the ignition system 50 further has lockout cycles C and start cycles S.
- the lockout cycles C are set to a predetermined value (such as 5 in an exemplary embodiment), and the start cycles S are set to a predetermined value (such as 5 in an exemplary embodiment).
- a start temperature is initiated, which is the initial temperature reading of the thermocouple 54 in the apparatus 10 .
- the system 50 provides a pre-purge period set at a predetermined time T1 such as 30 seconds in an exemplary embodiment. During a purge period it is understood that no gas is being supplied to the burner 28 and there should be no temperature readings showing a positive temperature change.
- the controller 56 reads the instant temperature sensed from the thermocouple 54 .
- the instant temperature sensed is greater than a set flame presence at start temperature limit F4, e.g., 650 degrees C. in an exemplary embodiment, a “flame detected at start” condition is determined. This can be an indication that a flame is already present in the apparatus 10 , the apparatus 10 is too hot to be ignited, or a possible electrical short is present in the apparatus. It is understood that the flame presence at start temperature limit F4 could be set at other values.
- the controller 56 determines a flame detected at start condition, the gas valve is shut off and the igniter is shut off.
- the controller 56 is configured to transmit a signal to shut down the burner. It is understood that shutting off the gas valve to interrupt the gas/fuel supply shuts down the burner.
- the gas valve 38 is associated with a pair of gas valve output relays K 3 , K 4 . The two relays are in serial activating the gas valve 38 .
- An alarm e.g., visual, audible, sensory perceptible etc.
- the start cycles S value previously initiated is also reduced by a value of 1. In such case, an ignition retry can be prepared ( FIG. 10 .) as explained below.
- the controller 56 determines if an increasing temperature condition is present. In particular, the controller 56 determines if the temperature sensed from the thermocouple 54 is greater than the initiated start temperature by a predetermined threshold value designated as Delta 5, e.g. 16° C. in an exemplary embodiment. If the temperature sensed is more than 16 degrees greater than the start temperature determined at initiation, a “flame detected at start” condition is determined. If the controller 56 determines a flame detected at start condition, the gas valve is shut off and the igniter is shut off. An alarm may also be signaled. The start cycles S value previously initiated is also reduced by a value of 1. In such case, an ignition retry can be prepared ( FIG. 10 .) as explained below.
- Delta 5 e.g. 16° C.
- a “flame detected at start” condition is not present, (e.g., the sensed temperature is not greater than 650° C. or the temperature is not increasing greater than 16° C. from the initiation start temperature), then the system 50 proceeds to the ignition phase. As further shown in FIG. 8 , at this phase, the igniter 52 is energized and the timer is again initiated. The alarm is not energized.
- the system 50 provides an igniter preheat, or warm-up period for a predetermined period of time T2, such as for 8 seconds. This allows the igniter 52 to attain an appropriate temperature condition to light the burner 28 .
- the gas valve 38 is opened and the timer is again initiated.
- the igniter 52 provides the necessary spark/energy to light the burner 28 and establish a flame.
- the controller 56 is now in a condition to determine if the igniter 52 has properly lit the burner 28 wherein a flame has been established.
- the controller 56 determines whether a threshold temperature difference exists from temperatures sensed by the thermocouple 54 .
- the controller 56 determines from the sensed temperatures if there is a temperature difference TPD2 of greater than or equal to 5° C. over any consecutive predetermined time period, such as 2 seconds.
- the timer is set for a trial for ignition period T3 for a predetermined time such as 14 seconds.
- the controller 56 operates in a loop to determine if the sensed temperature has increased by 5° C. over any 2 seconds of the 14 second trial for ignition period T3. If the timer reads a time that is greater than or equal to the trial for ignition period T3 and the controller 56 has determined that the required temperature increase TPD2 is not present, a sensing failure condition is determined by the controller 56 . In response to this condition, the gas valve 38 is shut off and the igniter 52 is shut off. This condition is also considered a lockout cycle occurrence wherein the initiated lockout cycle value C is reduced by 1. In such case, an ignition retry can be prepared ( FIG. 10 ) as explained below.
- the controller 56 determines a flame detected at start condition, or an ignition sensing failure, the controller 56 enters a prepare for ignition retry condition. In such condition as shown in FIG. 10 , the controller 56 first determines the countdown values of start cycles S and lockout cycles C. As discussed above, at initiation, the start cycle S and lockout cycles C were initiated to an initial value, such as 5. If the controller 56 determines that the start cycle S value is less than or equal to zero, an alarm is activated. The start cycle S value reading 0 may indicate a determination that the flame is present prior to commencement of the ignition phase where the igniter 52 is energized as shown in FIG. 8 .
- An operator can then troubleshoot the alarm, solve the problem and prepare the apparatus 10 and ignition system 50 to be re-initiated.
- the controller 56 determines that the lockout cycle C value is less than or equal to zero, an alarm is activated.
- the lockout value C value reading 0 may indicate that the flame is not present subsequent to a specified number of ignition attempts.
- the alarm may be perceptively different from the alarm generated regarding the start cycle S value.
- An operator can troubleshoot the alarm, solve the problem, and then prepare the apparatus 10 and ignition system 50 to be re-initiated. If the start cycle S value or the lockout cycle C value is greater than zero, the controller 56 proceeds to prepare for an ignition retry.
- the timer is initiated and an inter-purge period T4 is set, such as for 15 seconds.
- the timer is again initiated and the start temperature is again initiated at the current sensed temperature.
- the controller 56 then proceeds to the pre-purge period T1 wherein the timer is set for 30 seconds.
- the actual inter-purge period may be considered to be the combination of T1+T4.
- the controller 56 then again proceeds through the steps in FIG. 8 to ignite the burner 28 as described above.
- the controller 56 determines from the sensed temperatures that the temperature difference in any 2 consecutive seconds TPD2 meets the condition of being greater than or equal to the threshold temperature change of 5° C. (Delta 2), a flame detected condition is determined wherein the controller 56 concludes that the burner 28 has been properly lit and a flame exists at the burner 28 .
- a cooking flame is determined to be present based on the change in temperature detected by the temperature sensor is greater than the designated threshold temperature change and over a predetermined time period (e.g., in this instance Delta 2 and TPD2).
- the apparatus 10 is considered to be in a normal operation condition representing the operation phase, and the igniter is shut off. The timer is again initiated.
- a flame failure period T5 is set at a predetermined period, such as 14 seconds in an exemplary embodiment.
- the controller 56 monitors sensed temperatures to determine if there is a threshold temperature decrease TPD1 of 1° C. in any predetermined time period, such as 1 second. If such condition is not sensed, the timer is re-initiated. If the controller 56 determines from the sensed temperatures that there has been a temperature decrease of 1° C. but operation is still within the flame failure period T5, the controller 56 continues to monitor the temperature difference in any one second TPD 1 . If the controller 56 determines from the sensed temperatures that there has been a temperature decrease of 1° C.
- a flame failure condition is determined wherein the gas valve 38 is shut off and a visible alarm may be indicated.
- the apparatus can be re-initiated at Step 1.
- the flame failure is determined if the temperature decreases more than 1° C. over a 1 second time period and the condition has not been rectified in 14 seconds. This determination operates in a continuous loop through normal operation.
- the controller 56 determines if the sensed (instant) temperature is less than or equal to a minimum stage 1 temperature F2, such as 500° C. in an exemplary embodiment. If the minimum stage 1 temperature F2 is less than or equal to 500° C., the controller 56 determines if there is any negative temperature difference in any 2 consecutive seconds TPD2, unless or until the temperature returns to 500° C. or greater. Accordingly, the controller 56 continuously monitors if there is any drop in temperature in any 2 second period. If there is not such a temperature drop, the controller 56 operates in this loop and continuously monitors for a negative temperature difference in any 2 consecutive seconds TPD2, unless or until the temperature returns to 500° C. or greater. If the controller 56 does determine that the sensed temperature has dropped in any 2 consecutive seconds, a flame failure condition is determined wherein the gas valve 38 is shut off and a visible alarm may be indicated. In such case, the apparatus can be re-initiated at Step 1.
- a minimum stage 1 temperature F2 such as 500° C. in an exemplary embodiment. If the
- the controller 56 determines if the sensed temperature is greater than the minimum stage 1 temperature F2, e.g. 500° C., the controller 56 then determines if an additional predetermined temperature difference condition is present. In particular, the controller 56 monitors the sensed temperatures and determines whether there is a threshold negative temperature difference of 16° C. in any predetermined time period, such as 4 consecutive seconds TPD4. If the controller 56 determines that there has been a temperature drop of more than 16° C., a flame failure condition is determined wherein the gas valve 38 is shut off and a visible alarm may be indicated. In such case, the apparatus 10 can be re-initiated at Step 1. If the controller 56 determines that there has not been a temperature drop of more than 16° C., the controller 56 operates in a loop and continues to monitor temperature in the above fashion, which indicates that the apparatus 10 continues in the operation phase and operating normally.
- the ignition system 50 also has certain safety interlocks to shut down the apparatus 10 under certain conditions.
- the system has a high limit (maximum) temperature F MAX.
- F MAX is set at a threshold level or amount of 1023° C. If the controller 56 receives a sensed temperature greater than or equal to F MAX, the igniter 52 is shut off, the gas valve 38 is shut off and an alarm is activated.
- the system 50 has a low limit (minimum) temperature F MIN. In an exemplary embodiment, F MIN is set at a threshold level or amount of 0° C.
- the system 50 also has a maximum accepted delta temperature D MAX.
- D MAX is set at a threshold level or amount of 75° C. If the controller 56 receives sensed temperature readings of a threshold temperature difference greater than or equal to 75° C. in any 1 second TPD1 (e.g., a temperature rise), the igniter 52 is shut off, the gas valve 38 is shut off and an alarm is activated. Similarly, if the controller 56 receives sensed temperature readings of a threshold negative temperature difference greater than or equal to 75° C.
- any 1 second TPD1 e.g., a temperature drop
- the igniter 52 is shut off, the gas valve 38 is shut off and an alarm is activated. It is understood that all of the safety interlocks described herein can be analyzed over a predetermined period of time.
- the ignition system 50 also has thermocouple failure safety interlock.
- the thermocouple 52 utilizes the first sensor 55 and the second sensor 57 , which may also be considered two thermocouples in the sheath 59 .
- Each sensor 55 , 57 senses temperature in the apparatus. Under typical operation, the first sensor 55 and the second sensor 57 should have similar temperature readings. If the controller 56 determines that the sensed temperature readings between the first sensor 55 and the second sensor 57 are greater than or equal to a threshold amount, such as 100° C., the igniter 52 is shut off, the gas valve 38 is shut off and an alarm is activated.
- a threshold amount such as 100° C.
- the ignition system 50 has an igniter selection subroutine.
- the ignition system 50 utilizes a first igniter 52 and a second igniter 52 .
- the system 50 reads whether an acceptable minimum current is present in the first igniter 52 . If present, the system 50 operates in a loop wherein the first igniter 52 remains activated. If the first igniter 52 has a current that is less than the acceptable minimum current, a first igniter failure condition is determined and the system 50 switches to the second igniter 52 .
- a visible or audible alarm may be energized to indicate that the second igniter 52 is energized.
- An igniter timer delay is provided at a set time (e.g., 1300 milliseconds) wherein the system 50 also indicates that the first igniter is off.
- This igniter time delay provides an operator a short signal that the system 50 has changed from the first igniter 52 to the second igniter 52 . This provides an indication to the operator that the igniters 52 are in need of service.
- thermocouple 54 can be located at various locations. It has been determined that locating the thermocouple within the periphery of the flame 40 provides accurate data for use by the system 50 . It is further understood that the thermocouple 54 is positioned at the distal end 32 of the burner 28 in an exemplary embodiment. The thermocouple 54 could also be placed at other locations along the burner 28 .
- the ignition system 50 is used in a rotisserie oven 10 in one exemplary embodiment of the invention.
- the system is particularly suited for applications where fouling of a flame sensor from grease, surface contaminants or humidity is prevalent. It is understood that the ignition system or portions of the system used to confirm the presence of a flame, can be used in other types of flame-emitting apparatuses.
- FIG. 14 discloses a lighting application wherein a street lamp is connected to a fuel source to provide light.
- FIG. 15 discloses an outdoor heating lamp.
- FIG. 14 discloses a lighting application wherein a street lamp is connected to a fuel source to provide light.
- FIG. 15 discloses an outdoor heating lamp.
- Such cooking apparatuses include, but are not limited to, barbeque grills, boosters for heating water, fryers/donut fryers, salamander/cheesemelter, conventional ovens, accelerated cooking ovens, convection ovens, combi ovens, deck ovens, proofers, full size bakery ovens, char broilers (standard or upright), griddles, stove top/hot plates, rotisseries, pizza ovens (conveyor, deck, wood-gas combination), hot food tables (buffet style)/steam tables, ranges (multiple burners), waffle/crepe machines, stock pots, skillets/braising pans, pasta cookers, hot dog steamers, pannini machines, toasters, coffee roasters, wok ranges, Chinese pork roasters, vertical broilers, Mongolian barbeque grills, rethermalisers, rice cookers and soup kettles.
- the system can also include other non-cooking apparatuses including, but not limited to, gas lamps used for lighting purposes, outdoor heat lamps, outdoor decorative appliances, hot water heaters, boilers, dishwashers, commercial water heaters, commercial patio heaters, or other devices connected to a fuel source wherein the device emits a flame.
- gas lamps used for lighting purposes outdoor heat lamps, outdoor decorative appliances, hot water heaters, boilers, dishwashers, commercial water heaters, commercial patio heaters, or other devices connected to a fuel source wherein the device emits a flame.
- the ignition system 50 of the present invention provides benefits over prior art flame proving systems.
- the temperature sensor is positioned directly in the flame wherein more reliable temperature data can be obtained.
- the use of the algorithms further enhances operation in providing a more reliable system for proving that a flame exists after igniting the burner.
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Abstract
A flame-emitting apparatus is provided, whereby a burner has an inlet connected to a fuel source. Fuel burned by the burner provides a flame extending from an outlet of the burner. A flame ignition system detects the presence of the flame during operation of the apparatus and controls supply of fuel to the burner in response to flame detection.
Description
- The present application is a Continuation application and claims the benefit of U.S. patent application Ser. No. 13/101,821, filed on May 5, 2011, currently pending, which in turn claimed the benefit of priority to U.S. Provisional Patent Application. No. 61/331,702 filed May 5, 2010, expired, both of which are incorporated by reference herein and made a part hereof.
- 1. Field of the Invention
- The present invention generally relates to an ignition system for a flame-emitting apparatus and more particularly to an ignition system for a cooking apparatus such as a rotisserie oven that confirms the presence of a flame.
- 2. Background of the Invention
- Several types of apparatuses emit flames such as cooking apparatuses, heating lamps, gas lamps used for lighting and other decorative appliances. For operation of these apparatuses, a flame is ignited from a fuel source such as propane or natural gas. One type of cooking apparatus is a rotisserie oven. Rotisserie ovens are well known in the art. The ovens typically have a carousel mechanism or rotating member that rotates food items during cooking. The food items are supported by skewers that are removably connected to the rotating member. The rotisserie oven typically has a burner in communication with a fuel source. The ovens further have an ignition system used to initially ignite the burner. It is desirable for the system to confirm that the burner is properly ignited to avoid injecting fuel into the oven when a flame is not present in the burner to combust the fuel. It is also desirable to monitor if the burner flame is ever unexpectedly extinguished in order to interrupt the supply of fuel until the burner can again be properly ignited. Prior ignition systems experience difficulties in properly confirming that a flame is present when initially igniting the burner or confirming a flame continues to be present during operation of the oven. The flame-emitting apparatuses, including cooking ovens, may have a flame detecting system as part of an ignition system or a separate system that may use a flame sensor to detect the presence of a flame. The flame sensor can become fouled and rendered inoperable. Flame-emitting apparatuses may also use flame rectification systems that pass a current through a flame to detect a flame and other systems may employ optical methods in detecting a flame. Because of limitations in the structure and methods of such prior art systems, false readings can occur or the system can experience the inability to obtain a reading to confirm the presence of a flame.
- Thus, while flame detecting systems according to the prior art provide a number of advantageous features, they nevertheless have certain limitations. The present invention seeks to overcome certain of these limitations and other drawbacks of the prior art, and to provide new features not heretofore available.
- The present invention provides a system for detecting a presence of a flame in a flame-emitting apparatus. The system may be part of an ignition system for the flame-emitting apparatus that confirms the presence of a flame. In one exemplary embodiment, the ignition system is used in a cooking apparatus.
- According to one aspect of the invention, a system detects the presence of a flame in a flame-emitting apparatus. The flame-emitting apparatus has a burner and the burner is in communication with a fuel source. The burner emits a flame when the burner is fully ignited. The system has a temperature sensor configured to be positioned in the apparatus and is adjacent the burner wherein the sensor is configured to be positioned within the flame of the burner. A controller is operably connected to the temperature sensor and the burner wherein the controller receives temperature data from the temperature sensor. The controller determines whether a flame is present based on the temperature data received, and when determining that a flame is not present, the controller is configured to interrupt the supply of fuel to the burner.
- According to another aspect of the invention, a rotisserie oven has a housing defining a cavity. A rotating member is positioned within the cavity and is configured to support and rotate a plurality of food items within the cavity. A burner is positioned within the housing and has an inlet configured to be in fluid communication with a fuel source. The burner further has an outlet allowing a flame member to extend therefrom into the cavity as a product of combusting fuel supplied to the burner. An ignition system is operably coupled to the housing and has an igniter positioned adjacent the burner. The system further has a temperature sensor positioned adjacent the burner wherein the sensor is positioned to be within an outer periphery of the flame. The system has an ignition controller operably coupled to the igniter and thermocouple and configured to control the delivery of fuel to the burner.
- According to another aspect of the invention, the controller of the ignition system utilizes an algorithm to detect temperature changes within a predetermined range and controls the delivery of fuel in response thereto.
- According to another aspect of the invention, a cooking apparatus has a housing defining an interior cavity configured for cooking a food item. A support member is configured for supporting the food item. A burner is configured to burn a fuel to emit a cooking flame to heat the food item. A temperature sensor has a portion positioned proximate the burner to detect a temperature of the cooking flame. A controller is in communication with the temperature sensor, and the controller is configured for analyzing output from the temperature sensor to determine if the cooking flame is present, based on a change in temperature detected by the temperature sensor.
- According to another aspect of the invention, a cooking apparatus has a housing defining an interior cavity configured for cooking a food item. A support member is configured for supporting the food item. A burner has an aperture, and the burner is configured to burn a fuel to emit a cooking flame from the aperture to heat the food item when the burner is ignited. A temperature sensor has a portion positioned proximate the aperture to detect a temperature of the cooking flame, wherein the portion of the temperature sensor is configured to be positioned within the cooking flame when the burner is ignited. A control system is in communication with the temperature sensor, and the control system is configured for analyzing output from the temperature sensor to determine if the cooking flame is present.
- These and other objects and advantages will be made apparent from the following description of the drawings and detailed description of the invention.
- To understand the present invention, it will now be described by way of example, with reference to the accompanying drawings in which:
-
FIG. 1 is a perspective view of a flame-emitting apparatus in the form of a cooking apparatus such as a rotisserie oven utilizing an ignition system according to the present invention; -
FIG. 2 is a front elevation view of the cooking apparatus utilizing the ignition system according to the present invention; -
FIG. 3 is a side perspective view of the cooking apparatus showing additional control components associated with the apparatus; -
FIG. 4 is a partial perspective view of a temperature sensor of the ignition system and a burner of the rotisserie oven; -
FIG. 5 is a schematic view of a thermocouple used in the ignition system of the present invention including a partial enlarged portion; -
FIG. 6 is a flow chart disclosing operational features of the ignition system according to the present invention; -
FIG. 7 is a flow chart disclosing an exemplary embodiment of certain operational features of the ignition system according to the present invention; -
FIGS. 8-10 are flow charts disclosing another exemplary embodiment of certain operational features of the ignition system according to the present invention; -
FIGS. 11 and 12 are flow charts disclosing safety interlocks associated with the embodiment of the ignition system ofFIGS. 8-10 ; -
FIG. 13 is a flow chart of an igniter selection subroutine associated with the embodiment of the ignition system ofFIGS. 8-10 ; -
FIG. 14 is a perspective view of a gas lighting lamp utilizing the ignition system of the present invention; -
FIG. 15 is a perspective view of a heating lamp utilizing the ignition system of the present invention; and -
FIG. 16 is a schematic diagram illustrating various control components according to an embodiment of the present invention. - While this invention is susceptible of embodiment in many different forms, there is shown in the drawings, and will herein be described in detail, preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated.
- The present invention relates generally to a variety of flame-emitting apparatuses including cooking apparatuses. A flame-emitting apparatus typically has some form of burner connected to a fuel source. The apparatus also may have an ignition system for initially igniting the fuel supplied to the burner. The present invention includes structures and methods that confirm the presence of a flame upon igniting the burner to assure proper operation. Such structures and methods may be an integral part of the ignition system or operably interact with the ignition system, and may be generally referred to as flame detecting systems, flame confirmation systems, flame proving systems, or flame rectification systems. Thus, the present invention applies to a wide variety of apparatuses including any type of cooking cavities as well as outdoor cooking devices, gas lamps used for lighting purposes, outdoor heat lamps, outdoor decorative appliances, hot water heaters, boilers or other devices connected to a fuel source wherein the device emits a flame. In a particular example disclosed herein, the device is a rotisserie oven and a detailed discussion is provided regarding the rotisserie oven. It is understood that the device could also be other types of cooking devices that have a burner positioned either in a cooking cavity or adjacent to the cooking cavity as an external heat source. It is further understood that the structures and methods described herein in detail apply to and can be utilized in any type of flame-emitting apparatus. The invention will now be described as utilized in one exemplary embodiment of a rotisserie oven.
- Referring now in detail to the Figures,
FIG. 1 discloses a rotisserie oven that can incorporate the present invention, the oven generally designated with thereference numeral 10.FIG. 1 illustrates theoven 10 that is configured to cook a plurality of food items. The food items may oftentimes be chickens or other types of birds although it is understood that various other food items can be cooked in theoven 10. Theoven 10 generally includes ahousing 14, a rotating orrotatable member 16, and aheating assembly 18. Thehousing 14 can be of any shape generally known in the art. Thehousing 14 has a plurality of walls defining aninterior cavity 20. Theinterior cavity 20 is generally defined by a top wall, a bottom wall, a rear wall, a front wall and a pair of sidewalls. Thehousing 14 has anaccess door 22 in the front wall for placing the food item into thehousing 14. The rotatingmember 16 may be in the form of a carousel mechanism and has aplate 24 rotatably mounted on each sidewall of thehousing 14. It is understood the rotatingmember 16 has a drive mechanism for rotating the rotatingmember 16. The rotatingmember 16 includes a plurality of support members orskewers 26 and may be considered a movable skewer assembly. A respective end of eachskewer 26 is removably mounted on theplates 24 of the rotatingmember 16. Thus, food items loaded onto theskewers 26 such that at least oneskewer 26 extends at least partially through the food item and theskewers 26 are rotated within thehousing 14 during cooking. - As shown in
FIG. 2 , theheating assembly 18 is operably associated with thehousing 14 and provides a heat source for heating theinterior cavity 20 and cooking the food item. Theheating assembly 18 typically has a heating element that in one exemplary embodiment is aburner 28 that is in fluid communication with a fuel source such as propane or natural gas. As shown inFIG. 2 , theburner 28 is generally positioned within thecavity 20 and generally at a bottom portion of thehousing 14. It is understood that theburner 28 can be positioned in other areas of thehousing 14. Theburner 28 is a tubular structure having aproximate end 30 and adistal end 32. Theburner 28 has a plurality ofapertures 34 along a length of theburner 28. Theburner 28 is in fluid communication with a gas supply 36 (FIG. 3 ) and a gas valve 38 (FIG. 3 ) is mounted between theproximate end 30 and thegas supply 36. As shown inFIGS. 2 and 4 , when theburner 28 is in operation and combusting the fuel or gas supplied by thegas supply 36, aflame 40 is emitted and extends from theapertures 34 in theburner 28. Theflame 40 has anouter zone 41 that defines anouter periphery 42 of theflame 40 and which generally may represent the hottest part of theflame 40. Theflame 40 further has amiddle zone 44 and aninner zone 46 that has little combustion due to lack of oxygen. It is understood that therotisserie oven 10 has a master controller 48 (FIG. 2 ) that controls theheating assembly 16 as well as other operational features of theoven 10. - As further shown in
FIGS. 2-13 and 16, therotisserie oven 10 further has anignition system 50. Theignition system 50 generally includes anigniter 52, atemperature sensor 54 and anignition controller 56. It is understood that a power supply, breakers, switches etc. are in operable communication with theignition controller 56. It is understood that theignition controller 56 may be considered a part of themaster controller 48 but is otherwise in operable communication with themaster controller 48. As explained in greater detail below, theignition system 50 may also be considered a flame proving system or flame confirmation system. - As shown in
FIGS. 2 and 3 , theigniter 52 is positioned generally at theproximate end 30 of theburner 28 and generally at afirst aperture 34 of theburner 28. Theigniter 52 may include a plurality ofigniters 52. Thetemperature sensor 54 is a highlysensitive thermocouple 54 in an exemplary embodiment. Thethermocouple 54 is a fast-acting thermal probe capable of reading temperatures in a very fast manner and at extreme temperatures. Thethermocouple 54 is mounted to thehousing 14 and is positioned proximate thedistal end 32 of theburner 28. Thethermocouple 54 is further positioned slightly above theapertures 34 of theburner 28. As can be appreciated fromFIG. 4 , thethermocouple 54 is positioned such that when theburner 28 is in operation and theflame 40 extends from theaperture 34, at least a portion of thethermocouple 54 is positioned directly within theflame 40 wherein thethermocouple 54 is positioned within theouter periphery 42 of theflame 40. Thethermocouple 54 may extend through a plurality of theflames 40 extending from theburner 28. As further shown inFIGS. 2 and 3 , theigniter 52 and thethermocouple 54 are each operably connected to theignition controller 56. -
FIG. 5 discloses thethermocouple 54 in greater detail. As discussed, thethermocouple 54 is designed to sense extreme temperatures as well as rapid temperature changes including increasing temperatures and decreasing temperatures. In one exemplary embodiment, thethermocouple 54 is considered a dual-probe unit having afirst sensor 55 and asecond sensor 57. Thefirst sensor 55 andsecond sensor 57 both sense the temperature from theburner 28. Thefirst sensor 55 may be considered to be the main sensor associated with thecontroller 56 for operation in the pre-ignition, ignition and operation phases. Thesecond sensor 57 is a type of witness sensor that senses temperature. The multi-sensor design is used in a safety interlock as described below. Thefirst sensor 55 and thesecond sensor 57 are housed within asheath 59 of thethermocouple 54 and are insulated from one another. A powder may be compacted in thesheath 59 at a distal end of thesensors sheath 59 may have a cap fastened at the end of thesheath 59 enclosing the sensors. - In one general aspect of operation when the
oven 10 is initially started up via theignition controller 56, thegas valve 38 is opened to supply gas to theburner 28. Theigniter 52 is activated to provide a spark, start-up flame or incandescence to light the fuel or gas supplied to theburner 28. If properly ignited,flames 40 should be present at theproximate end 30 and quickly migrate along theburner 28 to thedistal end 32 and extend from eachaperture 34 as shown inFIG. 2 . Thethermocouple 54 will be positioned directly within theflame 40, and thethermocouple 54 will sense a temperature change from an initial state prior to ignition. If theburner 28 is not fully ignited, for example, due to blockage in one or more of theapertures 34, thethermocouple 54 will not sense an appropriate temperature change as a flame will not be present at theburner 28. Temperature readings from thethermocouple 54 are communicated to theignition controller 56 wherein thecontroller 56 recognizes a “flame not detected” condition and sends a signal to shut thegas valve 38 to prevent non-combusted fuel from continuing to be supplied into theoven 10. Supplying un-burnt fuel into theoven 10 can create a hazard. The ignition sequence can be then be re-initiated after a predetermined amount of time or after suitable troubleshooting is performed if necessary. - The
ignition controller 56 also has software utilizing algorithms to further enhance the operation of theignition system 50 and confirm the presence of theflame 40 during and after ignition. The algorithms are generally used by thesystem 50 to perform certain steps in sensing whether a rate of temperature change as sensed by thethermocouple 54 is sufficient. As explained in greater detail below, thesystem 50 may include a plurality of different starting temperature windows that have a rate of temperature change value assigned to the particular window to aid in properly determining the presence of a flame. -
FIG. 16 illustrates an example embodiment of themaster controller 48 and theignition system 50. Themaster controller 48 in this example may be a general purpose or specialized computer device, and may include typical computer components, including a processor or processing system 110 (e.g., one or more microprocessors), a memory ormemory system 112, which may include RAM, ROM, storage memory, etc., and an interface orinterface system 114. Thememory 112 may include software including computer executable instructions for use by theprocessor 110, such as an operating system, applications, databases, etc. Theinterface 114 may include various types of interfaces, including input/output interfaces for user input and user-readable output, as well as communication interfaces, such as a modem, LAN interface, cellular or other wireless interface, connection port (USB, Firewire, etc.), or other types of interfaces. Themaster controller 48 may include further components in some embodiments, such as a power supply (e.g., a battery or other power source). - In the embodiment illustrated in
FIG. 16 , themaster controller 48 is in communication with theignition controller 56 of theignition system 50. Theignition controller 56 may include any of the components described above, including aprocessor 110,memory 112,interface 114, etc. Additionally, as indicated by the broken lines inFIG. 16 , theignition controller 56 may be considered part of themaster controller 48 in one embodiment, and likewise, themaster controller 48 may be considered part of theignition system 50. Theignition controller 56 is in communication with theigniter 52, thesensor 54, and theburner 28 in this embodiment, and can transmit to and/or receive signals from theigniter 52, thesensor 54, and/or theburner 28. For example, theignition controller 56 may transmit a signal to activate theigniter 52 or the burner 28 (e.g. the gas valve(s)). As another example, theignition controller 56 may receive a signal indicative of the current in theigniter 52 or the temperature data from thesensor 54. - If the
ignition controller 56 is separate from themaster controller 48, theignition controller 56 may transmit at least some signals received from theigniter 52, thesensor 54, and/or theburner 28 to the master controller. Likewise, in this configuration, some of the signals transmitted by theignition controller 56 to theigniter 52, thesensor 54, and/or theburner 28 may be transmitted in response to a signal from themaster controller 48. Further, if theignition controller 56 is separate from themaster controller 48, theigniter 52, thesensor 54, and/or theburner 28 may additionally or alternately be in communication with themaster controller 48, as indicated by the broken-line connectors inFIG. 16 . - It is understood that if the
ignition system 50 includesmultiple igniters 52,sensors 54, and/orburners 28, theignition controller 56 may be in communication with each of themultiple igniters 52,sensors 54, and/orburners 28. - Aspects of the processes, communications, algorithms/routines, calculations, analysis, etc. described herein may take the form of a computer program product stored by one or more computer-readable storage media having computer-readable program code, or instructions, embodied in or on the storage media (e.g., in the memory 112). The computer-readable storage media may be tangible and/or non-transitory. Any suitable computer readable storage media may be utilized, including hard disks, CD-ROMs, optical storage devices, magnetic storage devices, microchips, and/or any combination thereof. Additionally, signals transmitted as described herein may be transmitted wirelessly or through a wire or other tangible conducting medium.
-
FIG. 6 discloses the general operation of one exemplary embodiment of theignition system 50 utilizing certain algorithms in greater detail for detecting the presence of a flame.FIG. 7 discloses more specific examples of the operation of theignition system 50. At the initiation of the ignition phase, thegas valve 38 is opened and gas is supplied to theburner 28. Theignition controller 56 activates theigniter 52 to provide a spark, start-up flame or incandescence to ignite theburner 28. Thethermocouple 54 senses an initial temperature immediately following ignition and communicates such reading to theignition controller 56. Theignition controller 56 determines an initial rate of temperature change from the initial temperature and the temperature sensed immediately following ignition (such temperature will be considered the maximum value the temperature rose to upon this initial temperature change determination, and designated as sensed temperature TS) to determine if such change is sufficient. If a sufficient rate of temperature change is not detected, thesystem 50 determines that a “flame not detected” condition exists and theburner 28 has failed to ignite. Theignition controller 56 shuts off thegas valve 38 and the ignition process is stopped. After a purge time is completed to allow gas to sufficiently diffuse, the process can be re-initiated a predetermined number of times. If the trials exceed the predetermined number of times, the ignition process terminates and transmits a signal to the alarm output identifying there has been a safety lock. - As further shown in
FIG. 6 , if thethermocouple 54 senses temperatures resulting in a rate of temperature change that theignition controller 56 recognizes as being sufficient, theignition controller 56 recognizes that theflame 40 is detected from theburner 28. Theignition controller 56 also has a plurality of different temperature windows covering certain operating temperature ranges of theoven 10. For example, a first window W1 may be designated for a temperature range equal to or lower than a lowest oven temperature. A second window W2 may be designated for a second temperature range covering an intermediate range. Other windows W having other temperature ranges can also be designated including a final window Wn that represents the highest temperature range for theoven 10. Theignition controller 56 recognizes the sensed temperature TS corresponding to the highest temperature sensed at the initial inquiry as described above. As thesystem 50 continues through its operational steps, theignition controller 56 uses this initial highest sensed temperature TS and determines the corresponding window W to be used to further confirm the presence of a flame. As discussed, each window W corresponds to a temperature range of theoven 10. Each window W has a predetermined acceptable rate of temperature change (or threshold amount) that would indicate a flame is present. Initially, the ignition controller takes the first sensed temperature TS as discussed above and determines which window W the sensed temperature TS falls into. Thethermocouple 54 continues to sense temperature values that are communicated to theignition controller 56. Theignition controller 56 determines the rate of temperature change from the temperatures sensed by thethermocouple 54 and then determines if the rate of temperature change is sufficient for the given temperature window W. If the temperature change is sufficient for the given window W, it is determined that the flame is present and the burner is functioning correctly, and wherein that gas can still be supplied to theburner 28. As such, thesystem 50 continues to loop through these inquiries wherein thethermocouple 54 continues to sense temperature TS wherein the appropriate window W is determined as well as the rate of temperature change which is compared to the acceptable rate of temperature change for that window W. If theignition controller 56 does not sense a rate of temperature change that is sufficient for the particular window W, then a flame failure condition is detected by theignition controller 56 and thecontroller 56 shuts off thegas valve 38. It is understood that each window can be programmed for different rates of change. - Once the
ignition system 50 determines that theburner 28 has been properly ignited, theoven 10 continues to operate in normal fashion. It is understood that theignition system 50 continues to monitor the oven temperature continuously during operation. If, for example, theflame 40 from theburner 28 was unexpectedly extinguished during operation, thethermocouple 54 senses falling temperatures that are communicated to theignition controller 56. In response, theignition controller 56 shuts off thegas valve 38 to interrupt fuel supply to theburner 28. It is further understood that themaster oven controller 48 has a thermostat associated therewith. Themaster oven controller 48 may also shut-off theburner 28 based on cavity temperature readings associated with the thermostat and according to desired cooking parameters for the particular food items being cooked. For example, after the temperature reaches a certain level, the burner may be shut-off and then when the cavity temperature falls to a certain level, themaster controller 48 sends a signal for theburner 28 to again be ignited. Theignition system 50 is used to ignite theburner 28 according the description above. -
FIG. 7 discloses a set of operational parameters for theignition system 50 in accordance with another exemplary embodiment of the invention. As discussed, thesystem 50 determines several temperature differences during operation represented by the reference numeral DT4, wherein DT4 represents a temperature difference in any four seconds. Via the operator or automatic controls, thegas valve 38 is opened and gas is supplied to theburner 28. Theignition controller 56 activates theigniter 52 to provide a start-up spark, start-up flame or incandescence to theburner 28 and ignite theburner 28. Thethermocouple 54 senses temperature and communicates such temperature values to theignition controller 56. Theignition controller 56 determines whether a temperature difference exists that is greater than or equal to 30° C. as shown inFIG. 7 . If the determined temperature change does not meet this value, a “flame not detected” condition is recognized and theignition controller 56 concludes that theburner 28 failed to ignite. In response, theignition controller 56 shuts off thegas valve 38. After a preprogrammed purge time to allow the gas in theoven 10 to sufficiently diffuse, the ignition process can again be initiated as described above. Theignition system 50 may also be pre-programmed allowing re-initiation of the ignition process a set number of times. For example, thesystem 50 can be programmed to allow 5 ignition trials. If theburner 28 is not properly ignited after the fifth try, the operator must perform more detailed troubleshooting prior to re-initiating the ignition process. - As further shown in
FIG. 7 , if theignition controller 56 receives sensed temperature data from thethermocouple 54 and determines a temperature difference exists and is greater than or equal to 30° C., a “flame detected” condition is recognized. The upper limit of the initial sensed temperature is designated as TS. In this condition, theoven 10 continues to a normal operation condition. As discussed, a plurality of windows W are designated in theignition controller 56. In this exemplary embodiment, thesystem 50 has a first window W1, a second window W2 and a third window W3. The first window W1 is set for a temperature range of temperatures equal to or less than 600° C. The designated rate of temperature change for the first window W1 is a change of less than or equal to 5° C. The second window W2 is set for an initial temperature range between 600° C. to 900° C. The designated rate of temperature change for the second window W2 is a change of less than −25° C., e.g. a temperature drop of 25° C. A third window W3 is set for an initial temperature range of 900° C. or greater. The designated rate of temperature change for the third window W3 is a change of less than −35° C., e.g. a temperature drop of 35° C. Theignition controller 56 recognizes the initial sensed temperature value TS corresponding to the highest value sensed at the initial inquiry and determines which window W the temperature TS is assigned. For example, if the initial sensed temperature TS is 550° C., the first window W1 is designated and theignition controller 56 continues to receive sensed temperature values from thethermocouple 54. Theignition controller 56 determines if a temperature difference exists that is less than or equal to 5° C. If the determined temperature difference is less than or equal to 5° C., a “flame failure” condition is detected wherein theignition controller 56 shuts off the gas valve. The condition can then be troubleshot and the ignition sequence re-initiated when appropriate. If the determined temperature difference is not less than or equal to 5° C., a normal operation condition is detected whereinignition controller 56 continues to loop through sensed temperature values received from thethermocouple 54. As the temperature sensed by thethermocouple 54 continues to rise due the normal operation of theoven 10, theignition controller 56 again determines which window is designated. For example, as temperature rises, the TS value may rise to a value between 600° C. and 900° C. wherein the second window W2 is designated. Theignition controller 56 then determines if a temperature difference exists that is less than −25° C., e.g., whether a temperature drop of 25° C. exists. If this condition does exist, a “flame failure” is detected and theignition controller 56 shuts off the gas valve. If the determined temperature difference is not less than −25° C., e.g., a temperature drop of 25° C. does not exist, a normal operation condition continues to be detected wherein theignition controller 56 continues to loop through sensed temperature values received from thethermocouple 54. As the sensed temperature TS continues to rise due to the normal operation of theoven 10, theignition controller 56 again determines which window is designated. For example, as temperature rises, the TS value may rise to a value greater than 900° C. wherein the third window W3 is designated. Theignition controller 56 then determines if a temperature difference exists that is less than −35° C., e.g., whether a temperature drop of 35° C. exists. If this condition does exist, a “flame failure” is detected and theignition controller 56 shuts off the fuel valve. If the determined temperature difference is not less than −35° C., e.g., a temperature drop of 35° C. does not exist, a normal operation condition continues to be detected wherein theignition controller 56 continues to loop through sensed temperature values received from thethermocouple 54. Thus, the hardware and software/algorithms cooperate to provide a more reliable system to detect a flame appropriately and determine theburner 28 is operating properly. - It is understood that depending on initial oven temperature, the sensed temperature TS may be at a value wherein the certain windows may be skipped in the above described process. For example, the
oven 10 may have been operating and warm and is then re-ignited after a short period of down time. The sensed temperature TS may initially be at a level of over 600° C. wherein theignition controller 56 proceeds directly to the second window W2 in the process. The process can also start directly in the third window W3 depending on the value of the sensed temperature TS. -
FIGS. 8-13 disclose further exemplary embodiments regarding the ignition system and additional various algorithms used by the master controller to ignite and monitor operation of the apparatus. Similar elements of prior exemplary embodiments of the ignition system will be designated with like reference numerals. In this particular exemplary embodiment, theignition system 50 includes various stages including a pre-ignition phase, an ignition phase and an operating phase. The system further includes safety interlocks and an igniter selection subroutine to be described. It is understood that specific temperatures, temperature ranges and temperature changes are designated for the exemplary embodiment described and can be altered without departing from the invention. As described in greater detail below, it is understood that the controller associated with theignition system 50 analyzes output from the temperature sensor to determine if the cooking flame is present. In one exemplary embodiment, the analysis is based on a change in temperature detected by the temperature sensor. - As previously discussed, the
ignition system 50 may be employed in arotisserie oven 10 in an exemplary embodiment, but can also be used in other cooking apparatuses or other types of flame-emitting apparatuses. As shown inFIG. 8 , a pre-ignition phase is set in theapparatus 10 prior to the ignition phase. In the pre-ignition phase, certain settings associated with thecontroller 56 are initiated including a timer associated with thecontroller 56 being initiated to be set at “zero.” The timer is relied upon throughout the different phases of operation of theignition system 50 andapparatus 10. Theignition system 50 further has lockout cycles C and start cycles S. The lockout cycles C are set to a predetermined value (such as 5 in an exemplary embodiment), and the start cycles S are set to a predetermined value (such as 5 in an exemplary embodiment). A start temperature is initiated, which is the initial temperature reading of thethermocouple 54 in theapparatus 10. Thesystem 50 provides a pre-purge period set at a predetermined time T1 such as 30 seconds in an exemplary embodiment. During a purge period it is understood that no gas is being supplied to theburner 28 and there should be no temperature readings showing a positive temperature change. - After pre-purge period T1 elapses and the timer reads a time of greater than or equal to 30 seconds, the
controller 56 reads the instant temperature sensed from thethermocouple 54. As shown inFIG. 8 , if the instant temperature sensed is greater than a set flame presence at start temperature limit F4, e.g., 650 degrees C. in an exemplary embodiment, a “flame detected at start” condition is determined. This can be an indication that a flame is already present in theapparatus 10, theapparatus 10 is too hot to be ignited, or a possible electrical short is present in the apparatus. It is understood that the flame presence at start temperature limit F4 could be set at other values. If thecontroller 56 determines a flame detected at start condition, the gas valve is shut off and the igniter is shut off. Thus, thecontroller 56 is configured to transmit a signal to shut down the burner. It is understood that shutting off the gas valve to interrupt the gas/fuel supply shuts down the burner. It is further understood that thegas valve 38 is associated with a pair of gas valve output relays K3, K4. The two relays are in serial activating thegas valve 38. An alarm (e.g., visual, audible, sensory perceptible etc.) may also be signaled at the flame detected at start condition. The start cycles S value previously initiated is also reduced by a value of 1. In such case, an ignition retry can be prepared (FIG. 10 .) as explained below. As further shown inFIG. 8 , if thecontroller 56 senses the flame presence at start temperature limit F4 from thethermocouple 54 to be less than 650° C., thecontroller 56 then determines if an increasing temperature condition is present. In particular, thecontroller 56 determines if the temperature sensed from thethermocouple 54 is greater than the initiated start temperature by a predetermined threshold value designated asDelta 5, e.g. 16° C. in an exemplary embodiment. If the temperature sensed is more than 16 degrees greater than the start temperature determined at initiation, a “flame detected at start” condition is determined. If thecontroller 56 determines a flame detected at start condition, the gas valve is shut off and the igniter is shut off. An alarm may also be signaled. The start cycles S value previously initiated is also reduced by a value of 1. In such case, an ignition retry can be prepared (FIG. 10 .) as explained below. - If a “flame detected at start” condition is not present, (e.g., the sensed temperature is not greater than 650° C. or the temperature is not increasing greater than 16° C. from the initiation start temperature), then the
system 50 proceeds to the ignition phase. As further shown inFIG. 8 , at this phase, theigniter 52 is energized and the timer is again initiated. The alarm is not energized. Thesystem 50 provides an igniter preheat, or warm-up period for a predetermined period of time T2, such as for 8 seconds. This allows theigniter 52 to attain an appropriate temperature condition to light theburner 28. After the igniter warm-up period T2 has elapsed and the timer reads a time greater than or equal to T2, thegas valve 38 is opened and the timer is again initiated. Theigniter 52 provides the necessary spark/energy to light theburner 28 and establish a flame. Thecontroller 56 is now in a condition to determine if theigniter 52 has properly lit theburner 28 wherein a flame has been established. Thecontroller 56 determines whether a threshold temperature difference exists from temperatures sensed by thethermocouple 54. In particular, thecontroller 56 determines from the sensed temperatures if there is a temperature difference TPD2 of greater than or equal to 5° C. over any consecutive predetermined time period, such as 2 seconds. The timer is set for a trial for ignition period T3 for a predetermined time such as 14 seconds. Thus, thecontroller 56 operates in a loop to determine if the sensed temperature has increased by 5° C. over any 2 seconds of the 14 second trial for ignition period T3. If the timer reads a time that is greater than or equal to the trial for ignition period T3 and thecontroller 56 has determined that the required temperature increase TPD2 is not present, a sensing failure condition is determined by thecontroller 56. In response to this condition, thegas valve 38 is shut off and theigniter 52 is shut off. This condition is also considered a lockout cycle occurrence wherein the initiated lockout cycle value C is reduced by 1. In such case, an ignition retry can be prepared (FIG. 10 ) as explained below. - As discussed above, if the
controller 56 determines a flame detected at start condition, or an ignition sensing failure, thecontroller 56 enters a prepare for ignition retry condition. In such condition as shown inFIG. 10 , thecontroller 56 first determines the countdown values of start cycles S and lockout cycles C. As discussed above, at initiation, the start cycle S and lockout cycles C were initiated to an initial value, such as 5. If thecontroller 56 determines that the start cycle S value is less than or equal to zero, an alarm is activated. The start cycle S value reading 0 may indicate a determination that the flame is present prior to commencement of the ignition phase where theigniter 52 is energized as shown inFIG. 8 . An operator can then troubleshoot the alarm, solve the problem and prepare theapparatus 10 andignition system 50 to be re-initiated. Similarly, if thecontroller 56 determines that the lockout cycle C value is less than or equal to zero, an alarm is activated. The lockout value C value reading 0 may indicate that the flame is not present subsequent to a specified number of ignition attempts. The alarm may be perceptively different from the alarm generated regarding the start cycle S value. An operator can troubleshoot the alarm, solve the problem, and then prepare theapparatus 10 andignition system 50 to be re-initiated. If the start cycle S value or the lockout cycle C value is greater than zero, thecontroller 56 proceeds to prepare for an ignition retry. The timer is initiated and an inter-purge period T4 is set, such as for 15 seconds. After the inter-purge period T4 has elapsed, the timer is again initiated and the start temperature is again initiated at the current sensed temperature. Thecontroller 56 then proceeds to the pre-purge period T1 wherein the timer is set for 30 seconds. As such, the actual inter-purge period may be considered to be the combination of T1+T4. Thecontroller 56 then again proceeds through the steps inFIG. 8 to ignite theburner 28 as described above. - Referring back to
FIG. 8 , if during the trial for ignition period T3, thecontroller 56 determines from the sensed temperatures that the temperature difference in any 2 consecutive seconds TPD2 meets the condition of being greater than or equal to the threshold temperature change of 5° C. (Delta 2), a flame detected condition is determined wherein thecontroller 56 concludes that theburner 28 has been properly lit and a flame exists at theburner 28. Thus, a cooking flame is determined to be present based on the change in temperature detected by the temperature sensor is greater than the designated threshold temperature change and over a predetermined time period (e.g., in thisinstance Delta 2 and TPD2). In such case, theapparatus 10 is considered to be in a normal operation condition representing the operation phase, and the igniter is shut off. The timer is again initiated. - In the operation phase once the timer is initiated (
FIG. 9 ), a flame failure period T5 is set at a predetermined period, such as 14 seconds in an exemplary embodiment. During the flame failure period, thecontroller 56 monitors sensed temperatures to determine if there is a threshold temperature decrease TPD1 of 1° C. in any predetermined time period, such as 1 second. If such condition is not sensed, the timer is re-initiated. If thecontroller 56 determines from the sensed temperatures that there has been a temperature decrease of 1° C. but operation is still within the flame failure period T5, thecontroller 56 continues to monitor the temperature difference in any onesecond TPD 1. If thecontroller 56 determines from the sensed temperatures that there has been a temperature decrease of 1° C. and the time period is greater than or equal to the flame failure period T5 (14 seconds), a flame failure condition is determined wherein thegas valve 38 is shut off and a visible alarm may be indicated. In such case, the apparatus can be re-initiated atStep 1. In other words, the flame failure is determined if the temperature decreases more than 1° C. over a 1 second time period and the condition has not been rectified in 14 seconds. This determination operates in a continuous loop through normal operation. - During normal operation of the
apparatus 10, thecontroller 56 also determines if the sensed (instant) temperature is less than or equal to aminimum stage 1 temperature F2, such as 500° C. in an exemplary embodiment. If theminimum stage 1 temperature F2 is less than or equal to 500° C., thecontroller 56 determines if there is any negative temperature difference in any 2 consecutive seconds TPD2, unless or until the temperature returns to 500° C. or greater. Accordingly, thecontroller 56 continuously monitors if there is any drop in temperature in any 2 second period. If there is not such a temperature drop, thecontroller 56 operates in this loop and continuously monitors for a negative temperature difference in any 2 consecutive seconds TPD2, unless or until the temperature returns to 500° C. or greater. If thecontroller 56 does determine that the sensed temperature has dropped in any 2 consecutive seconds, a flame failure condition is determined wherein thegas valve 38 is shut off and a visible alarm may be indicated. In such case, the apparatus can be re-initiated atStep 1. - As further shown in
FIG. 9 , if thecontroller 56 determines that the sensed temperature is greater than theminimum stage 1 temperature F2, e.g. 500° C., thecontroller 56 then determines if an additional predetermined temperature difference condition is present. In particular, thecontroller 56 monitors the sensed temperatures and determines whether there is a threshold negative temperature difference of 16° C. in any predetermined time period, such as 4 consecutive seconds TPD4. If thecontroller 56 determines that there has been a temperature drop of more than 16° C., a flame failure condition is determined wherein thegas valve 38 is shut off and a visible alarm may be indicated. In such case, theapparatus 10 can be re-initiated atStep 1. If thecontroller 56 determines that there has not been a temperature drop of more than 16° C., thecontroller 56 operates in a loop and continues to monitor temperature in the above fashion, which indicates that theapparatus 10 continues in the operation phase and operating normally. - As shown in
FIG. 11 , theignition system 50 also has certain safety interlocks to shut down theapparatus 10 under certain conditions. The system has a high limit (maximum) temperature F MAX. In an exemplary embodiment, F MAX is set at a threshold level or amount of 1023° C. If thecontroller 56 receives a sensed temperature greater than or equal to F MAX, theigniter 52 is shut off, thegas valve 38 is shut off and an alarm is activated. Thesystem 50 has a low limit (minimum) temperature F MIN. In an exemplary embodiment, F MIN is set at a threshold level or amount of 0° C. If thecontroller 56 receives a sensed temperature less than or equal to F MIN, theigniter 52 is shut off, thegas valve 38 is shut off and an alarm is activated. Thesystem 50 also has a maximum accepted delta temperature D MAX. In an exemplary embodiment, D MAX is set at a threshold level or amount of 75° C. If thecontroller 56 receives sensed temperature readings of a threshold temperature difference greater than or equal to 75° C. in any 1 second TPD1 (e.g., a temperature rise), theigniter 52 is shut off, thegas valve 38 is shut off and an alarm is activated. Similarly, if thecontroller 56 receives sensed temperature readings of a threshold negative temperature difference greater than or equal to 75° C. in any 1 second TPD1 (e.g., a temperature drop), theigniter 52 is shut off, thegas valve 38 is shut off and an alarm is activated. It is understood that all of the safety interlocks described herein can be analyzed over a predetermined period of time. - As shown in
FIG. 12 , theignition system 50 also has thermocouple failure safety interlock. As discussed above, in an exemplary embodiment, thethermocouple 52 utilizes thefirst sensor 55 and thesecond sensor 57, which may also be considered two thermocouples in thesheath 59. Eachsensor first sensor 55 and thesecond sensor 57 should have similar temperature readings. If thecontroller 56 determines that the sensed temperature readings between thefirst sensor 55 and thesecond sensor 57 are greater than or equal to a threshold amount, such as 100° C., theigniter 52 is shut off, thegas valve 38 is shut off and an alarm is activated. - As shown in
FIG. 13 , theignition system 50 has an igniter selection subroutine. In an exemplary embodiment, theignition system 50 utilizes afirst igniter 52 and asecond igniter 52. Thesystem 50 reads whether an acceptable minimum current is present in thefirst igniter 52. If present, thesystem 50 operates in a loop wherein thefirst igniter 52 remains activated. If thefirst igniter 52 has a current that is less than the acceptable minimum current, a first igniter failure condition is determined and thesystem 50 switches to thesecond igniter 52. A visible or audible alarm may be energized to indicate that thesecond igniter 52 is energized. An igniter timer delay is provided at a set time (e.g., 1300 milliseconds) wherein thesystem 50 also indicates that the first igniter is off. This igniter time delay provides an operator a short signal that thesystem 50 has changed from thefirst igniter 52 to thesecond igniter 52. This provides an indication to the operator that theigniters 52 are in need of service. - It is understood that the
thermocouple 54 can be located at various locations. It has been determined that locating the thermocouple within the periphery of theflame 40 provides accurate data for use by thesystem 50. It is further understood that thethermocouple 54 is positioned at thedistal end 32 of theburner 28 in an exemplary embodiment. Thethermocouple 54 could also be placed at other locations along theburner 28. - The
ignition system 50 is used in arotisserie oven 10 in one exemplary embodiment of the invention. The system is particularly suited for applications where fouling of a flame sensor from grease, surface contaminants or humidity is prevalent. It is understood that the ignition system or portions of the system used to confirm the presence of a flame, can be used in other types of flame-emitting apparatuses. For example,FIG. 14 discloses a lighting application wherein a street lamp is connected to a fuel source to provide light.FIG. 15 discloses an outdoor heating lamp. The above discussion regarding the ignition system and detecting the presence of a flame applies to such apparatuses. Other apparatuses where the invention can be utilized include other types of cooking apparatuses. Such cooking apparatuses include, but are not limited to, barbeque grills, boosters for heating water, fryers/donut fryers, salamander/cheesemelter, conventional ovens, accelerated cooking ovens, convection ovens, combi ovens, deck ovens, proofers, full size bakery ovens, char broilers (standard or upright), griddles, stove top/hot plates, rotisseries, pizza ovens (conveyor, deck, wood-gas combination), hot food tables (buffet style)/steam tables, ranges (multiple burners), waffle/crepe machines, stock pots, skillets/braising pans, pasta cookers, hot dog steamers, pannini machines, toasters, coffee roasters, wok ranges, Chinese pork roasters, vertical broilers, Mongolian barbeque grills, rethermalisers, rice cookers and soup kettles. - The system can also include other non-cooking apparatuses including, but not limited to, gas lamps used for lighting purposes, outdoor heat lamps, outdoor decorative appliances, hot water heaters, boilers, dishwashers, commercial water heaters, commercial patio heaters, or other devices connected to a fuel source wherein the device emits a flame.
- The
ignition system 50 of the present invention provides benefits over prior art flame proving systems. The temperature sensor is positioned directly in the flame wherein more reliable temperature data can be obtained. The use of the algorithms further enhances operation in providing a more reliable system for proving that a flame exists after igniting the burner. - While the specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention and the scope of protection is only limited by the scope of the accompanying Claims.
Claims (20)
1. An ignition system for flame emitting devices, the system comprising:
a. a burner;
b. a temperature sensor positioned proximate to said burner; and
c. a controller in communication with said temperature sensor, the controller configured to analyze output from the sensor, including a current temperature and changes in the temperature, to determine if a flame is present.
2. The system as recited in claim 1 , wherein the controller is further configured for analyzing an instant temperature detected by the temperature sensor to determine whether the flame is present.
3. The system as recited in claim 1 , wherein the controller is configured to determine that the flame is present if the change in temperature determined by the controller is greater than a threshold temperature change.
4. The system as recited in claim 3 , wherein the controller is configured to determine that the flame is present if the change in temperature detected by the temperature sensor is greater than the threshold temperature change over a predetermined time period.
5. The system as recited in claim 1 , wherein the controller is further configured to transmit a signal to shut down the burner if:
the controller determines that the flame is present prior to commencement of an ignition attempt; or
the controller determines that the flame is not present subsequent to a specified number of ignition attempts.
6. The system as recited in claim 1 , further comprising an igniter configured for igniting the burner to emit the flame, wherein the igniter is in communication with the controller and the controller is configured to transmit signals to cause activation of the igniter.
7. The system as recited in claim 1 , wherein the controller is further configured to transmit a signal to shut down the burner if:
the temperature detected by the temperature sensor is higher than a maximum temperature; or
the temperature detected by the temperature sensor is lower than a minimum temperature; or
the temperature detected by the temperature sensor decreases by a first threshold amount over a time period; or
the temperature detected by the temperature sensor increases by a second threshold amount over the time period.
8. The system as recited in claim 1 , wherein the temperature sensor comprises a thermocouple.
9. A flame emitting apparatus comprising:
a. a burner having an aperture, the burner configured to burn a fuel to emit a flame from the aperture when the burner is ignited;
b. a temperature sensor having a portion positioned proximate the aperture to detect a temperature of the flame, wherein the portion of the temperature sensor is configured to be positioned within the flame when the burner is ignited; and
c. a control system in communication with the temperature sensor, the control system configured for analyzing output from the temperature sensor to determine if the flame is present.
10. The apparatus as recited in claim 9 , wherein the controller is further configured for determining if the flame is present based on at least one of a change in temperature detected by the temperature sensor and an instant temperature detected by the temperature sensor.
11. The apparatus as recited in claim 10 , wherein the controller is configured to determine that the flame is present if:
the change in temperature detected by the temperature sensor is greater than a threshold temperature change over a predetermined time period; or
the instant temperature detected by the temperature sensor is greater than a minimum threshold.
12. The apparatus as recited in claim 9 , wherein the controller is further configured to transmit a signal to shut down the burner if:
the controller determines that the flame is present prior to commencement of an ignition attempt; or
the controller determines that the flame is not present subsequent to a specified number of ignition attempts.
13. The apparatus as recited in claim 9 , further comprising:
an igniter configured for igniting the burner to emit the flame, wherein the igniter is in communication with the controller and the controller is configured to transmit signals to cause activation of the igniter.
14. The apparatus as recited in claim 9 , wherein the controller is further configured to transmit a signal to shut down the burner if:
the temperature detected by the temperature sensor is higher than a maximum temperature; or
the temperature detected by the temperature sensor is lower than a minimum temperature; or
the temperature detected by the temperature sensor decreases by a first threshold amount over a time period; or
the temperature detected by the temperature sensor increases by a second threshold amount over the time period.
15. The apparatus as recited in claim 9 , wherein the temperature sensor comprises a thermocouple having an end configured to be positioned within the flame.
16. The apparatus as recited in claim 9 , wherein the temperature sensor comprises two thermocouples, and the controller is further configured to transmit a signal to shut down the burner if a difference between temperatures detected by the two thermocouples is greater than a threshold amount.
17. The apparatus as recited in claim 9 , wherein the burner comprises a plurality of apertures, the burner configured to emit flames from each of the apertures, and wherein the portion of the temperature sensor is configured to be positioned within at least one of the flames when the burner is ignited.
18. A method for detecting a flame, said method comprising the steps of:
a. receiving a first reading from a temperature sensor;
b. waiting a predetermined amount of time;
c. receiving a second reading from a temperature sensor; and
d. determining whether a difference between the second reading and the first reading is within an acceptable range for passage of the predetermined time.
19. The method of claim 18 , further comprising the step of returning a “flame detected” condition if the difference between the first reading and second reading is within an acceptable range for the passage of the predetermined time or returning a “flame not detected” condition if the difference between the first reading and second reading is not within an acceptable range for the passage of the predetermined time.
20. A control unit configured to practice the method of claim 18 .
Priority Applications (1)
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US14/229,512 US20140212821A1 (en) | 2010-05-05 | 2014-03-28 | Ignition system for flame emitting apparatus |
Applications Claiming Priority (3)
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US33170210P | 2010-05-05 | 2010-05-05 | |
US201113101821A | 2011-05-05 | 2011-05-05 | |
US14/229,512 US20140212821A1 (en) | 2010-05-05 | 2014-03-28 | Ignition system for flame emitting apparatus |
Related Parent Applications (1)
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US201113101821A Continuation | 2010-05-05 | 2011-05-05 |
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US20140212821A1 true US20140212821A1 (en) | 2014-07-31 |
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US14/229,512 Abandoned US20140212821A1 (en) | 2010-05-05 | 2014-03-28 | Ignition system for flame emitting apparatus |
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US (1) | US20140212821A1 (en) |
Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150276268A1 (en) * | 2014-03-25 | 2015-10-01 | Honeywell International Inc. | Pilot light control for an appliance |
US20170079475A1 (en) * | 2015-09-18 | 2017-03-23 | 7794754 Canada Inc. | Atmospheric rotisserie burner with convection heating |
JP2017077394A (en) * | 2015-10-21 | 2017-04-27 | リンナイ株式会社 | grill |
US20170276353A1 (en) * | 2016-03-28 | 2017-09-28 | Azbil Corporation | Combustion controlling system |
CN107238104A (en) * | 2016-03-28 | 2017-10-10 | 阿自倍尔株式会社 | Combustion control system |
US9799201B2 (en) | 2015-03-05 | 2017-10-24 | Honeywell International Inc. | Water heater leak detection system |
US9885484B2 (en) | 2013-01-23 | 2018-02-06 | Honeywell International Inc. | Multi-tank water heater systems |
US9920930B2 (en) | 2015-04-17 | 2018-03-20 | Honeywell International Inc. | Thermopile assembly with heat sink |
US10088852B2 (en) | 2013-01-23 | 2018-10-02 | Honeywell International Inc. | Multi-tank water heater systems |
US10119726B2 (en) | 2016-10-06 | 2018-11-06 | Honeywell International Inc. | Water heater status monitoring system |
US10132510B2 (en) | 2015-12-09 | 2018-11-20 | Honeywell International Inc. | System and approach for water heater comfort and efficiency improvement |
US10969143B2 (en) | 2019-06-06 | 2021-04-06 | Ademco Inc. | Method for detecting a non-closing water heater main gas valve |
EP3933267A1 (en) * | 2020-07-01 | 2022-01-05 | ebm-papst Landshut GmbH | Method for monitoring a flame in a combustion chamber of a torch |
US11592852B2 (en) | 2014-03-25 | 2023-02-28 | Ademco Inc. | System for communication, optimization and demand control for an appliance |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5791890A (en) * | 1995-08-18 | 1998-08-11 | General Electric Company | Gas oven control with proof of ignition |
US6289792B1 (en) * | 1999-08-31 | 2001-09-18 | Op Controls Spa | Gas barbecue with flame timer for grilling food |
US20020125241A1 (en) * | 1998-06-04 | 2002-09-12 | Allen Scott | Electric water heater with pulsed electronic control and detection |
-
2014
- 2014-03-28 US US14/229,512 patent/US20140212821A1/en not_active Abandoned
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5791890A (en) * | 1995-08-18 | 1998-08-11 | General Electric Company | Gas oven control with proof of ignition |
US20020125241A1 (en) * | 1998-06-04 | 2002-09-12 | Allen Scott | Electric water heater with pulsed electronic control and detection |
US6289792B1 (en) * | 1999-08-31 | 2001-09-18 | Op Controls Spa | Gas barbecue with flame timer for grilling food |
Cited By (23)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10088852B2 (en) | 2013-01-23 | 2018-10-02 | Honeywell International Inc. | Multi-tank water heater systems |
US9885484B2 (en) | 2013-01-23 | 2018-02-06 | Honeywell International Inc. | Multi-tank water heater systems |
US20150276268A1 (en) * | 2014-03-25 | 2015-10-01 | Honeywell International Inc. | Pilot light control for an appliance |
US11592852B2 (en) | 2014-03-25 | 2023-02-28 | Ademco Inc. | System for communication, optimization and demand control for an appliance |
US10670302B2 (en) * | 2014-03-25 | 2020-06-02 | Ademco Inc. | Pilot light control for an appliance |
US9799201B2 (en) | 2015-03-05 | 2017-10-24 | Honeywell International Inc. | Water heater leak detection system |
US10049555B2 (en) | 2015-03-05 | 2018-08-14 | Honeywell International Inc. | Water heater leak detection system |
US10692351B2 (en) | 2015-03-05 | 2020-06-23 | Ademco Inc. | Water heater leak detection system |
US9920930B2 (en) | 2015-04-17 | 2018-03-20 | Honeywell International Inc. | Thermopile assembly with heat sink |
US10738998B2 (en) | 2015-04-17 | 2020-08-11 | Ademco Inc. | Thermophile assembly with heat sink |
US10051995B2 (en) * | 2015-09-18 | 2018-08-21 | 7794754 Canada Inc. | Atmospheric rotisserie burner with convection heating |
US20170079475A1 (en) * | 2015-09-18 | 2017-03-23 | 7794754 Canada Inc. | Atmospheric rotisserie burner with convection heating |
JP2017077394A (en) * | 2015-10-21 | 2017-04-27 | リンナイ株式会社 | grill |
US10989421B2 (en) | 2015-12-09 | 2021-04-27 | Ademco Inc. | System and approach for water heater comfort and efficiency improvement |
US10132510B2 (en) | 2015-12-09 | 2018-11-20 | Honeywell International Inc. | System and approach for water heater comfort and efficiency improvement |
CN107238104A (en) * | 2016-03-28 | 2017-10-10 | 阿自倍尔株式会社 | Combustion control system |
US10274196B2 (en) * | 2016-03-28 | 2019-04-30 | Azbil Corporation | Combustion controlling system |
US10139107B2 (en) * | 2016-03-28 | 2018-11-27 | Azbil Corporation | Combustion controlling system |
CN107238099A (en) * | 2016-03-28 | 2017-10-10 | 阿自倍尔株式会社 | Combustion control system |
US20170276353A1 (en) * | 2016-03-28 | 2017-09-28 | Azbil Corporation | Combustion controlling system |
US10119726B2 (en) | 2016-10-06 | 2018-11-06 | Honeywell International Inc. | Water heater status monitoring system |
US10969143B2 (en) | 2019-06-06 | 2021-04-06 | Ademco Inc. | Method for detecting a non-closing water heater main gas valve |
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