WO1998026219A1

WO1998026219A1 - A gas burner having a flame keeper cell and a sensor positioned therein

Info

Publication number: WO1998026219A1
Application number: PCT/US1997/023233
Authority: WO
Inventors: Joseph B. Adamski; William E. Nothe; Bruce Janvrin
Original assignee: Raytheon Company
Priority date: 1996-12-12
Filing date: 1997-12-12
Publication date: 1998-06-18

Abstract

A gas burner having a flame keeper cell and a sensor positioned in the flame keeper cell to assure that a no flame signal is sent to the control system for the burner only when the burner flame is completely extinguished. During initial lighting of the burner or after the burner flame is completely extinguished, the control system attempts ignition only a limited number of times or during a limited time period and then the flow of gas to the burner is stopped thereby presenting excessive gas discharge into the atmosphere.

Description

A GAS BURNER HAVING A FLAME KEEPER CELL AND A SENSOR POSITIONED THEREIN

1 FIELD OF THE INVENTION

2 The present invention relates to gas burners which include a sensor for detecting

3 the presence or absence of a flame and for sending a signal to a control circuit to initiate ignition. In particular, the gas burner structure includes a flame keeper cell which reduces

5 the possibility of the entire burner flame being extinguished by a gust of air or other

6 circumstances and the placement of the sensor within the flame keeper cell.

7

8 BACKGROUND OF THE INVENTION Many commercial and household appliances such as cooktop and free standing gas ιo ranges use gas burners. The typical gas burner is generally circular in shape and π comprises a center portion with an orifice through which gas is supplied, a substantially

12 vertical peripheral wall portion having a plurality of quench ports, an igniter cell, and a

13 flame keeper cell both offset from the wall portion and a cap positioned over the center

1 portion and the wall portion. The gas enters the burner and is lit by an igniter positioned is in the igniter cell. A ring of fire extends around the circumference of the burner and the

16 ring of fire is maintained by the gas passing through the plurality of quench ports. The

17 flame or fire is also present within the flame keeper cell. The flame keeper cell is offset or is recessed from the circumference of the burner so that a gust of air or other circumstances

1 which may extinguish the flame being fed from the quench ports may not extinguish the

20 flame within the flame keeper cell. Once the gust of air is over the flame within the flame 2i keeper cell is sufficient to automatically relight the burner.

22 If the flame is completely extinguished and accordingly not automatically relit from

23 the flame keeper cell, the gas will continue to be inputted into the burner and as a result

24 noxious gas will escape into the environment causing the risk of explosion and a health

25 hazard. Accordingly, it is important to detect when the burner flame is completely

26 extinguished and signal the igniter to relight the gas. n There are many known sensor systems which determine the presence or absence of

28 a flame. These systems include well known optical devices and ionization devices. The

29 presence or absence of a burner flame is typically determined by placing a sensor adjacent

30 to one of the quench ports of the burner. If the flame is extinguished at the quench port the sensor sends a "no flame" signal to a burner control circuit which in turn sends a signal to the igniter to relight the burner. However, if the burner has already been relit from an unextinguished flame in the flame keeper cell, then any attempts to reignite the burner causes an annoying sound which can be heard by the user and can cause electromagnetic interference. In addition, a sensor placed adjacent a quench ports of the burner can become damaged from food splatters or abrasive/caustic material used in cleaning the burner. This may cause the sensor to malfunction or become inoperative. Thus there^' is a need for a burner with a flame sensor which only provides a no flame signal to the control circuit when the entire burner flame is completely extinguished. There is also a need for a burner with a flame sensor in which the sensor is sheltered from food splatters, cleaning solution and other external substances that may damage the sensor.

SUMMARY OF THE INVENTION The invention is a gas burner with a flame keeper cell and a flame sensor positioned within the flame keeper cell to determine the presence or absence of a gas flame. The gas burner can be of any construction provided it includes a flame keeper cell. The burner can be used in any product but for purposes of illustration is described as a cooktop range burner. The sensor can be of any design or technology but for purposes of illustration is described as a optical detector. A gas valve having a normally closed position and an open position supplies gas from a source to the burner. The user opens the gas valve by turning a knob or activating some other control device on the range. The valve begins supplying gas to the burner and sends a signal indicating the gas valve is open to a controller. The flame sensor positioned within the flame keeper cell sends a signal to the controller indicating that there is no flame at the burner. The controller repeatedly sends a signal to the igniter for lighting the gas as long as both the gas on signal and the no flame signal are present at the controller. Once the gas is lit the flame sensor sends a signal indicating the presence of a flame at the burner to the controller which then ceases to send the ignite signal to the igniter. While the burner is operating a gust of air or other conditions can extinguish the burner flame around the periphery of the burner but may not extinguish the flame in the flame keeper cell. In this circumstance, once the gust of wind or other circumstance has abated the flame in the flame keeper cell will automatically relight the gas. However, if the burner flame is completely extinguished, the flame sensor sends a signal indicating no flame at the burner to the controller. The ignition sequence described above is then begun. In an alternative embodiment, the number of ignite signals sent from the controller to the igniter are counted or the length of time during which the controller sends the ignite signal to the igniter is counted and when either the number of signals or the length of time exceeds a predetermined valve a disable signal is sent to the gas valve causing it to close. Of course, once the gas valve is closed, the controller will no longer receive the valve open signal and the controller will stop sending ignite signals to the igniter. This embodiment enhances the safety of the system by limiting the length of time and correspondingly the amount of gas which escapes to the atmosphere if combustion is not taking place. In another alternative embodiment, a manual gas valve and an electrically controlled gas valve are placed in series. Both the manual gas valve and the electric gas valve must be in the open position before gas is supplied to the burner. The user opens the manual valve which sends a gas on signal to a microprocessor but gas is not yet supplied to the burner since the electric valve is closed. When the microprocessor receives both the gas on signal from the manual gas valve and a no flame signal from the sensor placed in the flame keeper cell of the burner it sends a signal to the electric valve causing it to open. Gas now flows to the burner and the microprocessor sends an ignite signal to the ignitor. If combustion doesn't take place at the burner after a certain number of attempts to ignite the gas or the passage of a certain amount of time, the microprocessor sends a signal to the electric valve causing it to close which shuts off the gas flow to the burner even though the manual valve remains open. At the same time the microprocessor sends the signal to the electric valve causing it to close, the microprocessor sets an internal inhibit which prevents the ignite signal from being sent to the igniter. The inhibit is removed when the user closes the manual valve thereby removing the gas on signal to the microprocessor. An important feature of the present invention is the placement of the sensor within the flame keeper cell. Since the burner flame is last extinguished in the flame keeper cell the placement of the sensor within the flame keeper cell eliminates the possibility of a false flame extinguished condition which occurs when a peripherally mounted sensor determines the flame is out and the controller attempts to relight the flame after it has already been relit from the flame in the flame keeper cell. In addition, the sensor positioned within the flame keeper cell is sheltered from food splatters and other external materials that could damage the sensor.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages of the invention will become apparent upon reading the following detailed description and upon reference to the accompanying drawings, in which: FIG. 1 is a perspective view of a typical gas burner. FIG. 2 is a perspective view of the typical gas burner of FIG. 1 with the lid removed. FIG. 3 is a cross-sectional view of the gas burner of FIG. 2 along line 3-3 showing the igniter and the position of the flame sensor in the flame keeper cell according to the present invention. FIG. 4 is a block diagram of the control system for the gas burner of the present invention. FIG. 5 is a block diagram of an alternative control system for the gas burner of the present invention. FIG. 6 is a block diagram of another alternative control system for the gas burner of the present invention. FIG. 7 is a flow diagram of the operation of the microprocessor shown in FIG. 6. While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is 1 not intended to be limited to the particular forms disclosed. On the contrary, the

2 applicant's intention is to cover all modifications, equivalents, and alternatives falling

3 within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

5 Referring to the drawings, wherein the same reference characters designate like or

6 corresponding parts throughout the views, FIG. 1 shows a typical gas burner 10 having a

7 lower body or wall portion 12 and a lid or cap 14 positioned over and extending slightly

8 beyond the body portion 12. A plurality of quench ports 16 are formed around the

9 circumference of the body portion 12. As is well known, the number of quench ports 16 ιo as well as their width, length and height is a matter of design choice and well within the n abilities of someone of ordinary skill in the field. An opening to a flame keeper cell 18 is

12 formed within body portion 12 while the flame keeper cell 18 is slightly recessed or offset

13 from the wall portion 12. In the preferred embodiment, a Sourdillion burner with a flame

14 keeper cell is used. However, it should be understood that the present invention can be is used with any burner regardless of its size, shape or structure provided it has a flame

16 keeper cell or the equivalent thereof.

17 FIG. 2 shows the burner 10 of FIG. 1 with the lid or cap 14 removed. The burner is has a central portion 20 connected to the body or wall portion 12. The central portion 20

19 has an opening 22 through which gas is fed into the burner 10. An igniter cell 24 is

20 positioned approximately 180° degrees from the flame keeper cell 18. The igniter cell 24 i and the flame keeper cell 18 can be positioned anywhere along the circumference of the 2 body portion 12 and are both slightly offset or recessed. The structure and operation of

23 the typical burner 10 is well known to those of ordinary skill in the art and hence is only 4 described herein in general terms.

25 The user of the burner 10 typically turns a knob or activates an on/off device on

26 the range which in turn opens a normally closed valve and allows gas to enter the burner

27 10 through the opening 22 in the central portion 20. The gas is lit by an igniter 26 which 8 includes the appropriate circuitry positioned in the igniter cell 24 and the burner flame 9 extends around the periphery of the body portion 12. As is well known, the gas is fed i through the quench ports 16 in order to maintain the flame around the circumference of

2 the burner 10. The flame is also present in the flame keeper cell 18. Since the flame

3 keeper cell 18 is recessed from the periphery of the burner 10 the flame is sheltered from

4 the ambient environment. For example a gust of air across the burner 10 or variation in

5 room or gas line pressure may extinguish the flame around the periphery but the flame in

6 the flame keeper cell 18 is less likely to be put out because it is sheltered. Accordingly, if

7 the flame around the periphery is put out but the flame in the flame keeper cell 18 remains

8 lit, then once the air gust or other condition is over the entire burner 10 is automatically

9 relit from the flame in the flame keeper cell 18. ιo FIG. 3 is a cross section of the burner of FIG. 2 along line 3-3 with the igniter 26 π and a flame sensor 28 shown positioned within the igniter cell 24 and the flame keeper cell

12 18 respectively. The igniter 26 is well known to one of ordinary skill in the field and any

13 type or kind of igniter including appropriate circuitry can be used. The flame sensor 28

14 can be any sensor for determining the presence or absence of a flame such as an optical or is ionization sensor. While the type, size, design and structure of the flame sensor is not

16 relevant to the present invention, in the preferred embodiment, the sensor 28 is an optical

17 sensor sensitive to the visible light spectrum. However, it should be appreciated that a is ultraviolet optical sensor could also be used since burning gas flames emit a portion of

19 their energy in the ultraviolet range. In the preferred embodiment, the optical sensor 28 is

20 positioned at the bottom of the flame keeper cell 18 and is pointing in an upward 2i direction. Since the sensor 28 in the flame keeper cell 18 is sheltered from ambient light it

22 can operate without the difficulty of distinguishing between the flame and ambient light.

23 In addition, the flame sensor 28 positioned in the flame keeper cell 18 is protected from

24 damage due to food splatters or other external influences which may cause it to

25 malfunction or fail. Both the igniter 26 and the flame sensor 28 are connected to a 6 controller or control system (not illustrated in FIG. 3). Since the flame in the flame keeper

27 cell 18 will be the last flame to be extinguished by a gust of air or other external

28 conditions, placing the flame sensor 28 in the flame keeper cell 18 assures that a no flame

29 signal is sent to the controller only when the burner flame is completely extinguished. FIG. 4 is a block diagram of the control system for the burner 10. An on/off device 30 is connected via line 32 to the gas valve 34. The on/off device 30 can be any device such as a knob or switch on the gas range. The gas valve 34 can be any kind of valve but in the preferred embodiment the valve is an electrically controlled bi-metal safety valve which is normally off and is well known to those of ordinary skill in the field. The operator using the on/off device 30 opens the gas valve 34 which is connected via line 36 to a source of gas 38 and allows gas to flow from the source 38 through the opening 22 into the burner 10; The valve 34 sends a signal on line 40 to a controller 42 indicating that the valve 34 is open. The flame sensor 28 positioned within the flame keeper cell 18 sends a no flame signal on line 44 to the controller 42. When the controller 42 receives a valve open signal on line 40 and a no flame signal on line 44, it repetitively sends a signal on line 46 to igniter 26 causing it to light the gas. Once the gas flame is lit the sensor 28 detects the presence of the flame and removes the no flame signal from line 44 or sends a flame present signal on line 44 to controller 42. In either event the controller 42 stops sending the signal on line 46 to the igniter 26. As is well know in the field the flame keeper cell 18 is slightly offset or recessed from the periphery of the burner 10. Accordingly, a gust of air which is sufficient to extinguish the flame at the various quench ports 16 may not extinguish the flame in the flame keeper cell 18, in which case once the gust of air has terminated, the burner flame is automatically relit from the flame in the flame keeper cell 18. If the flame in the flame keeper cell 18 is extinguished the flame sensor 28 positioned in the flame keeper cell 18 sends a no flame on line 44 to the controller 42. Upon receipt of the no flame signal on line 44 and the valve open signal on line 40 the controller 42 repetitively sends the ignite signal on line 46 to igniter 26. The controller 42 continues sending the ignite signal to igniter 26 until the flame sensor 28 detects the presence of a flame or the gas valve 34 is turned off by the operator. In the preferred embodiment, the controller 42 is a simple gate circuit, well within the abilities of someone of ordinary skill in the field. However, any type of control circuit capable of performing the functions described can be used. FIG. 5 is a block diagram of an alternative control system for the burner 10. The control system operates as explained above with the addition of a counter circuit 48 1 connected to the line 46 by line 50. The counter 48 keeps track of the number of times

2 that the controller 42 attempts to light igniter 26 or the length of time during which the

3 controller 42 is sending the ignite signal to the igniter 26. If the counter 48 reaches a

4 predetermined value without being reset by the flame present signal on line 52, it sends a

5 signal on line 54 to valve 34 causing it to close. When the valve 34 is closed, the gas on

6 signal on line 40 is removed and accordingly, the controller 42 stops sending the ignite

7 signal on line 46 to the igniter 26. The use of the counter 48 limits the time period during

8 which the igniter 26 is attempting to light the burner 10 and the gas is flowing to the

9 burner 10. Thus, the amount of gas which escapes into the environment is limited. ιo FIG. 6 is another alternative control system for the burner 10 according to the π present invention. The burner 10 is fully described in reference to FIGS. 1-3 but shown

12 here is diagram form for the sake of clarity. In general, the burner 10 comprises a wall

13 portion 12 having a plurality of quench ports 16, a lid 14, a flame keeper cell 18 and a

14 ignition cell 24. As indicated above, the burner 10 can have any size, shape or structure

15 provided it has a flame keeper cell 18. An igniter 26 is positioned in the ignition cell 24

16 and lights the gas which flows into the burner 10 to form a ring of flame through the

17 quench ports 16 around the periphery of the wall portion 12. Instead of placing the flame is sensor 28 directly in the flame keeper cell 18 a fiber optic element or cable 58 is placed in

19 the flame keeper cell 18 and connected to the sensor 28. Of course, as is well known,

20 light is transmitted along the fiber optic cable directly to the sensor 28. Since the fiber 2i optic cable is part of or an extension of the sensor 28, this structure is the same or

22 equivalent to placing the sensor 28 in the flame keeper cell 18 and connecting it

23 electrically to the control system. Of course, if the sensor 28 is an ultraviolet detector

24 then the fiber optic cable 58 must transmit the ultraviolet spectrum to the sensor 28 as is

25 well known to those of ordinary skill in the field.

₂6 In operation, the user opens the normally closed manual valve 34 by turning a

27 knob or other on/off device (not illustrated) usually mounted on the top of the range. Gas 8 now flows from the source 38 through the manual valve 34 but does not pass through a

29 normally closed electrically operated valve 60 which is connected in series with the manual

30 valve 34. Any electrically operated valve can be used, in the preferred embodiment, a bi- metal valve is used. The series arrangement of manual valve 34 and electric valve 60 provides additional safety as is explained below. By opening manual valve 34, a switch 62 closes which provides a valve open signal on line 64 to a microprocessor 66. In the preferred embodiment a Motorola 68MCO5 microprocessor is used. However, any microprocessor capable of performing the functions described can be used as is known to one of ordinary skill in the field. One end of the fiber optic cable 58 is positioned within the flame keeper cell 18 while the other end is associated with the sensor 28. The sensor 28 is connected to an amplifier circuit 68 which increases the strength of the signal from the sensor 28. The output of the amplifier circuit 68 is connected to one input of a comparator 70. A variable resistor 72 is connected to the other input of the comparator 70. By changing the value of variable resistor 72 the magnitude of the signal to the second input of comparator 70 is changed and the sensitivity of the flame detection is modified. Since the flame is not present in the flame keeper cell 18 the signal to the second input of comparator 70 exceeds the first input from the amplifier 68. The output from the comparator 70 on line 72 indicates that no flame is detected. Since the microprocessor 66 received the gas on signal on line 64 and the no flame signal on line 72, it produces signal on line 74 which is connected to the base of transistor 76. The transistor 76 is now conductive which causes a current to flow through the coil of relay 78 which closes the relay 78 and thereby opens the bi-metal valve 60 so that gas now passes to the burner 10. Since the bi-metal valve 60 requires a finite time to open, the microprocessor 66 delays sending a signal on line 80 to an ignition circuit 82 and then the igniter 26. The ignition circuit 82 can be any well known circuitry to support the igniter 26 such as a set-up transformer and is well known to those of ordinary skill in the field. The delay assures that gas is being provided to the burner 10 before the igniter 26 attempts to light the gas. Once the delay is over and the bi-metal gas valve 60 is open, gas flows in line 84 to the burner 10 and the microprocessor 66 sends a signal on line 80 through ignition circuit 82 to ignitor 26 which causes the burner flame to ignite. The microprocessor keeps track of the number of lines that the ignitor attempts to light the burner flame or in the alternative the length of time that the igniter has been firing. If the count, either the number of firings or the length of time, exceed a predetermined number, the microprocessor removes the signal from line 74 and consequently no current flows through the coil of relay 78 and thereby the bi-metal valve 60 closes to prevent gas from flowing in line 84 to the burner 10. The predetermined number is a matter of design choice. Once the bi-metal valve is closed, the microprocessor inhibits further operation until the manual valve 34 is closed which removes the gas on signal on line 64 to the microprocessor 66. The removal of the gas on signal on line 64 causes the microprocessor 66 to release the inhibit or to reset. Without the inhibit, the microprocessor 66 would detect the gas on signal on line 64 and the no flame signal on line 72 and reopen bi-metal valve 60 to begin another ignition sequence. If the burner 10 is lit before the number of ignite attempts or the length of line exceeds the predetermined value, then visible light is transmitted over the fiber optic cable 58 to the sensor 28. The amplifier 68 increases the magnitude of the signal from sensor 28 and applies it to the negative input of comparator 70. Now, the signal at the negative input exceeds the signal from the variable resistor 72 applied to the positive input of the comparator 70. A flame present signal is now applied on line 72 to the microprocessor 66 which then stops applying the ignite signal on line 80 to the igniter 26. Now, if the burner 10 is lit and a gust of air or other external conditions cause the burn flamed to be completely extinguished, no visable light is transmitted over fiber optic cable 58 to the sensor 28. Accordingly, the amplified signal applied to the negative input of comparator 70 falls below the signal from the variable resistor 72 applied to the positive input to the comparator 70. A no flame signal is now applied on line 72 to the microprocessor 66 and the ignite sequence explained above is begun. The functional operation of the microprocessor 66 is shown in FIG. 7. The microprocessor 66 is idle at step 100 waiting for the detection of user input. If the manual valve 34 is not open at step 102, the process continues in the idle state. If the manual valve 34 is open, then at step 104 the process checks to determine if the inhibit has been released to permit the microprocessor to receive user inputs. If the inhibit is not released, the process returns to idle at step 100. If the inhibit is released the microprocessor 66 1 receives the new manual valve 34 gas on signal at step 106. The process then checks to

2 determine of a flame is detected by sensor 28 at step 108. If a flame is detected then the

3 process stops at step 110. If no flame is detected at step 108, then the microprocessor 66

4 sends a signal to open the bi-metal valve 60 at step 112. Next, the ignition count is set to

5 zero at step 114 and a delay is initiated at step 116 to give the bi-metal valve 60 an

6 opportunity to open. If time is used instead of the number of attempts to light the burner,

7 then the clock is set to zero and the timing begins at step 114. After the delay is over, an

8 ignite signal is sent to the ignitor 26 at step 118. Now the igniter count is incremented at

9 step 120. If time is being used, then at step 120, the amount of time is checked. If the lo igniter count or the time is less than the predetermined number N at step 122, then the u process checks to determine if a flame is present at step 124. If a flame is present, then at

12 step 126 the process stops. If the flame is not detected at step 124, then the process sends

13 another ignite signal at step 118. This process continues until the igniter count or time at

14 step 122 is greater than the predetermined number N or the burner flame is detected. is Now at step 128, the process checks to determine if a flame is detected. If a flame is

16 detected the process stops at step 130. If a flame is not detected at step 120 that indicates

17 that the burner flame is not ignited despite several attempts or the passage of a is predetermined time period. Now, the bi-metal control valve 60, is closed at step 132 to

19 prevent gas from flowing to the burner 10. The process at step 134 inhibits the operation 0 of the microprocessor 66 until the user closes the manual valve 34 to remove the gas on i signal on line 64 and at step 136, the process stops. ₂ It will be understood that various changes in the details, arrangements and 3 configurations of the parts and assembles which have been described and illustrated above 4 in order to explain the nature of the present invention may be made by those of ordinary 5 skill in the field within the principle and scope of the present invention as expressed in the 6 appended claims. It is not intended to limit the invention to the precise forms disclosed 7 above and many modifications and variations are possible in light of the above teaching.

Claims

i WHAT IS CLAIMED IS:

2 1. A gas burner comprising:

3 a central portion having an orifice for receiving gas;

4 an upwardly extending wall portion connected to said central portion and having a

5 plurality of quench ports, an ignition cell and a flame keeper cell;

6 an igniter positioned in said ignition cell and capable of lighting said gas;

7 a sensor positioned in said flame keeper cell and capable of detecting the presence

₈ or absence of a flame; and

9 a cap covering said central portion and said wall portion.

o 2. A gas burner as set forth in claim 1 further comprising: i a valve having a normally closed position and an open position for controlling the flow of said gas to said orifice; and 3 a control circuit connected to said igniter, said sensor, and said valve.

4 3. A gas burner as set forth in claim 2 wherein said sensor comprises: s a fiber optic element having a first and second end, said first end positioned 6 in said flame keeper cell and capable of transmitting light emitted by a flame to said second end: and s a detector positioned adjacent to said second end of said fiber optic 9 element and capable of responding to light transmitted through said fiber optic element.

i 4. A gas burner as set forth in claim 2 wherein: said valve sends a gas on signal to said control circuit when placed in said open 3 position; ₄ said sensor sends a no flame signal to said control circuit when there is no flame 5 present in said flame keeper cell; 6 said control circuit receiving said gas on signal and said no flame signal and as long as both signals are present repetitively sends an ignite signal to said igniter; ₈ said igniter receiving each of said ignite signals and attempting to ignite said gas.

1 5. A gas burner as set forth in claim 4 further comprising:

2 a counter circuit connected to said control circuit for counting the number of ignite

3 signals sent to said igniter by said control circuit;

4 said counter circuit sending a disable signal to said valve when the number of ignite

5 signals exceeds a predetermined limit; and

6 said valve upon receiving said disable signal returns to said closed position.

7 6. A gas burner as set forth in claim 5 wherein said sensor also sends a flame signal to

8 said counter circuit when there is a flame present in said flame keeper cell and said

9 counter circuit upon receiving said flame signal is reset.

0 7. A gas burner as set forth in claim 4 further comprising: 1 a counter circuit connected to said control circuit for counting the time 2 during which said control circuit sends said ignite signals; 3 said circuit counter sending a disable signal to said valve when the time 4 during which said control circuit sends said ignite signals exceeds a 5 predetermined limit; 6 said valve upon receiving said disable signal returns to said closed position. 7 s 8. A gas burner as set forth in claim 7 wherein said sensor also sends a flame signal to 9 said counter circuit when there is a flame present in said flame keeper cell and said counter 0 circuit upon receiving said flame signal is reset.

i 9. A gas burner system comprising a burner having a plural of quench ports, an 2 igniter cell and a flame keeper cell, a valve having a closed position and an open position 3 for connecting a source of gas to said burner and generating a valve open signal when said 4 valve is in said open position, an igniter positioned in said igniter cell, a flame sensor 5 positioned in said flame keeper cell for generating a no flame signal when there is no 6 flame in said flame keeper cell and a controller connected to said igniter, said flame sensor 7 and said valve for receiving said no flame signal and said valve open signal and repetitively 8 sending an ignite signal to said igniter.

10. A gas burner system as set forth in claim 9 further comprising a counter circuit connected to said controller for determining the number of ignite signals sent by said controller to said igniter and generating a disable signal when said number of ignite signals exceeds a predetermined number; and said valve upon receiving said disable signal returns to said closed position.

11. A gas burner system as set forth in claim 10 wherein said sensor also generating a flame signal when there is a flame in said flame keeper cell and said counter upon receiving said flame signal is reset.

12. A gas burner system as set forth in claim 9 further comprising a counter circuit for detecting the length of time said controller generates said ignite signals and generating a disable signal when the time that said controller generates said ignite signals exceeds a predetermined limit; and said valve upon receiving said disable signal returns to said closed position.

13. A gas burner system as set forth in claim 12 wherein said sensor also generating a flame signal when there is a flame in said flame keeper cell and said counter upon receiving said flame signal is reset.

14. A gas burner system as set forth in claim 9 wherein said sensor comprises: a fiber optic element having a first and second end, said first end positioned in said flame keeper cell and capable of transmitting light emitted by a flame to said second end; and a detector positioned adjacent to said second end of said fiber optic element and capable of responding to light transmittal through said fiber optic element.

15. A gas burner system comprising a burner having a flame keeper cell and an igniter cell, an igniter positioned in said igniter cell, a manual valve connected to a source of gas, an electrically operated valve connected between said manual valve and said burner, said manual valve having a first position blocking the flow of gas to said burner and second position permitting the flow of gas to said burner and for generating a gas on signal, said electrically operated valve having a first position blocking the flow of gas to said burner and a second position permitting the flow of gas to said burner, a flame sensor positioned in said flame keeper cell for generating a no flame signal, a controller connected to said flame sensor and said electrically operated valve and said manually operated valve for receiving said no flame signal and said gas on signal and sending an enable signal to said electrically operated valve to position said electrically operated valve in said second position and sending signals to said igniter to light the gas and after a predetermined number of signals are sent to said igniter or the predetermined period of time has passed without said burner being lit sending a disable signal to said electrically operated valve to position said electrically operated valve in said first position.

16. A gas burner system as set forth in claim 15 wherein said flame sensor generates a flame signal when said burner is lit and said controller upon receiving said flame signal from said sensor ceases sending signals to said igniter to light the gas.