Fuel burner supervisory system

Claim 2

A fuel burner supervisory system comprising first and second flame sensors, each said flame sensor adapted to be individually responsive to flame in the supervised fuel burner and to produce a flame signal output as a result of sensing flame in the supervised fuel burner, cyclically operative means associated with said first and second flame sensors for periodically simulating flame absence for each sensor, the interval of simulated flame absence for each sensor being less than a predetermined interval of time, first circuitry responsive to the flame signal output of said first sensor and having a first state indicative of the absence of a flame signal output from said first sensor for interval greater than said predetermined interval of time and a second state indicative of the presence of a flame signal output from said first flame sensor, second circuitry responsive to the flame signal output of said second sensor and having a first state indicative of the absence of a flame signal output from said second flame sensor for an interval of time greater than said predetermined time interval and a second state indicative of the presence of a flame signal output from said second flame sensor, first and second switching means, said first switching means enabling flow of fuel to said fuel burner in response to said first circuitry in said second state independently of said second switching means, second switching means enabling flow of fuel to said fuel burner in response to said second circuitry in said second state independently of said first switching means, and third circuitRy responsive to said first and second circuitries, said third circuitry including a flame failure alarm connected to signal when both said first circuitry and said second circuitry are in their first states, thus indicating a likely absence of flame.

Claim 3

The system of claim 1 wherein said first and second switching means are flame relays, an alarm associated with each said relay, and each said relay is connected to actuate its associated alarm when in its second state.

Claim 4

The system of claim 2 further comprising two electrical power sources, contacts, under the respective control of said relays, through which said sources are adapted to be connected in parallel to a fuel valve to control the position thereof, contacts, under the respective control of said relays, through which said sources are adapted to be connected to their associated alarms, and contacts, under the effective respective control of said relays, connected in series in said third circuitry with said flame failure alarm.

Claim 5

The system of claim 3 wherein said last mentioned contacts are in series with a third power source.

Claim 6

The system of claim 1 wherein said sensors and said cyclically operative means are mounted in a sealed housing and liquid cooling jacket surrounds said housing.

Claim 7

The system of claim 5 wherein said jacket is mounted in a guide tube to provide a space within said tube surrounding said jacket for the flow of air past said housing to clear debris from in front of said sensors.

Claim 8

The system of claim 6 wherein said guide tube includes at its forward end air deflector and radiation suppressor structure defining an optical aperutre for said sensors.

Claim 9

The system of claim 1 wherein said sensors are of the ulta-violet sensitive, avalanche-breakdown type.

Claim 10

The system of claim 6 mounted in a combustion chamber having a burner nozzle, said guide tube being mounted directly adjacent said nozzle and being rigidly fixed to said nozzle for movement with said nozzle.

Claim 11

A fuel burner supervisory system comprising an elongated tubular member, air deflector and radiation suppressor means at one end of said tubular member, said air deflector and radiation suppressor means defining an outlet port, means for supporting said tubular member with said outlet port adjacent the fuel nozzle of the supervised burner, a sensor assembly disposed in said tubular member, said sensor assembly comprising a sealed housing, jacket structure spaced rom said housing to define a chamber to which cooling liquid may be supplied for flow around said housing, optical window structure in the front wall of said housing, first and second photoelectric flame sensors in said housing in fixed optical alignment with said optical window structure and said outlet port, shutter means in said housing interposed between said sensors and said optical window means, and means to operate said shutter means for simulating at periodic intervals flame absence for each sensor, inelt passage means extending through said tubular member from a point remote from said outlet port to said jacket structure for supplying cooling liquid to said chamber to cool components mounted in said housing, outlet passage means extending through said tubular member from said jacket structure to a point remote from said outlet port for receiving cooling liquid after said cooling liquid has circulated through said chamber, means mounting said sensor assembly in spaced relation to said tubular member, and port means in said tubular member at a point remote from said outlet port through which air may be introduced for flow past said sensor assembly and out said outlet port to clear debris from in front of the front wall of said housing.

Claim 12

A fuel burner supervisory system comprising an elongated tubular member, air deflector and radiation suppressor means at one end of said tubular member, said air deflector and radiation suppressor means defining an outlet port, means for supporting said tubular member with said outlet port adjacent the fuel nozzle of the supervised burner, a sensor assembly disposed in said tubular member, said sensor assembly comprising a sealed housing, jacket structure spaced rom said housing to define a chamber to which cooling liquid may be supplied for flow around said housing, optical window structure in the front wall of said housing, first and second photoelectric flame sensors in said housing in fixed optical alignment with said optical window structure and said outlet port, shutter means in said housing interposed between said sensors and said optical window means, and means to operate said shutter means for simulating at periodic intervals flame absence for each sensor, inelt passage means extending through said tubular member from a point remote from said outlet port to said jacket structure for supplying cooling liquid to said chamber to cool components mounted in said housing, outlet passage means extending through said tubular member from said jacket structure to a point remote from said outlet port for receiving cooling liquid after said cooling liquid has circulated through said chamber, means mounting said sensor assembly in spaced relation to said tubular member, and port means in said tubular member at a point remote from said outlet port through which air may be introduced for flow past said sensor assembly and out said outlet port to clear debris from in front of the front wall of said housing.

Claim 13

A fuel burner supervisory system comprising an elongated tubular member, air deflector and radiation suppressor means at one end of said tubular member, said air deflector and radiation supressor means defining an outlet port, means for supporting Said tubular member with said outlet port adjacent the fuel nozzle of the supervised burner, a sensor assembly disposed in said tubular member, said sensor assembly comprising a sealed housing, jacket structure spaced from said housing to define a chamber through which cooling liquid may be supplied, optical window structure in the front wall of said housing, first and second photoelectric flame sensors in said housing in fixed optical alignment with said optical window structure and said outlet port, shutter means in said housing interposed between said sensors and said optical window means, and means to operate said shutter for simulating periods of flame absence for each sensor, inlet passage means extending through said tubular member from a point remote to said outlet port to said jacket structure for supplying cooling liquid to said chamber to cool components mounted in said housing, outlet passage means extending through said tubular member from said jacket structure to a point remote from said outlet port for receiving cooling liquid after said cooling liquid has circulated through said chamber, means mounting said sensor assembly in spaced relation to said tubular member, port means in said tubular member at a point remote from said outlet port through which air may be introduced for flow past said sensor assembly and out said outlet port to clear debris from in front of the front wall of said housing, first circuitry responsive to the flame signal output of said first sensor and having a first state indicative of the absence of a flame signal output from said first sensor and a second state indicative of the presence of a flame signal output from said first flame sensor, second circuitry responsive to the flame signal output of said second sensor and having a first state indicative of the absence of a flame signal output from said second flame sensor and a second state indicative of the presence of a flame signal output from said second flame sensor, first and second switching means, said first switching means enabling flow of fuel to said fuel burner in response to said first circuitry in said second state independently of said second switching means, second switching means enabling flow of fuel to said fuel burner in response to said second circuitry in said second state independently of said first switching means, and third circuitry responsive to said first and second circuitries, said third circuitry including a flame failure alarm connected to signal when both said first circuitry and said second circuitry are in their first states, thus indicating a likely absence of flame.

Claim 14

A fuel burner supervisory system comprising an elongated tubular member, air deflector and radiation suppressor means at one end of said tubular member, said air deflector and radiation supressor means defining an outlet port, means for supporting Said tubular member with said outlet port adjacent the fuel nozzle of the supervised burner, a sensor assembly disposed in said tubular member, said sensor assembly comprising a sealed housing, jacket structure spaced from said housing to define a chamber through which cooling liquid may be supplied, optical window structure in the front wall of said housing, first and second photoelectric flame sensors in said housing in fixed optical alignment with said optical window structure and said outlet port, shutter means in said housing interposed between said sensors and said optical window means, and means to operate said shutter for simulating periods of flame absence for each sensor, inlet passage means extending through said tubular member from a point remote to said outlet port to said jacket structure for supplying cooling liquid to said chamber to cool components mounted in said housing, outlet passage means extending through said tubular member from said jacket structure to a point remote from said outlet port for receiving cooling liquid after said cooling liquid has circulated through said chamber, means mounting said sensor assembly in spaced relation to said tubular member, port means in said tubular member at a point remote from said outlet port through which air may be introduced for flow past said sensor assembly and out said outlet port to clear debris from in front of the front wall of said housing, first circuitry responsive to the flame signal output of said first sensor and having a first state indicative of the absence of a flame signal output from said first sensor and a second state indicative of the presence of a flame signal output from said first flame sensor, second circuitry responsive to the flame signal output of said second sensor and having a first state indicative of the absence of a flame signal output from said second flame sensor and a second state indicative of the presence of a flame signal output from said second flame sensor, first and second switching means, said first switching means enabling flow of fuel to said fuel burner in response to said first circuitry in said second state independently of said second switching means, second switching means enabling flow of fuel to said fuel burner in response to said second circuitry in said second state independently of said first switching means, and third circuitry responsive to said first and second circuitries, said third circuitry including a flame failure alarm connected to signal when both said first circuitry and said second circuitry are in their first states, thus indicating a likely absence of flame.

Claim 15

The system of claim 11 wherein said first and second switching means are flame relays, an alarm associated with each said relay, and each said relay is connected to actuate its associated alarm when in its second state.

Claim 16

The system of claim 12 further comprising two electrical power sources, contacts, under the respective control of said relays, through which said sources are adapted to be connected in parallel to a fuel valve to control the position thereof, contacts, under the respective control of said relays, through which said sources are adapted to be connected to their associated alarms, and contacts, under the effective respective control of said relays, connected in series in said third circuitry with said flame failure alarm.

Claim 17

The system as claimed in claim 13 wherein said last mentioned contacts are in series with a third power source.

Claim 18

The system as claimed in claim 14 wherein said sensors are of the ultra-voilet sensitive, avalanche-breakdown type.