US3644748A - Combustion supervision apparatus - Google Patents

Combustion supervision apparatus Download PDF

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Publication number
US3644748A
US3644748A US3644748DA US3644748A US 3644748 A US3644748 A US 3644748A US 3644748D A US3644748D A US 3644748DA US 3644748 A US3644748 A US 3644748A
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United States
Prior art keywords
contacts
flame
relay
coil
lockout
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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English (en)
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Philip E Lord
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Electronics Corp of America
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Electronics Corp of America
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Publication date
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N5/00—Systems for controlling combustion
    • F23N5/22—Systems for controlling combustion with a time programme acting through mechanical means, e.g. using cams
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N2227/00—Ignition or checking
    • F23N2227/04—Prepurge
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N2227/00—Ignition or checking
    • F23N2227/12—Burner simulation or checking
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N2229/00—Flame sensors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N2231/00—Fail safe
    • F23N2231/20—Warning devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N2233/00—Ventilators
    • F23N2233/06—Ventilators at the air intake

Definitions

  • ABSTRACT Combustion supervision apparatus includes a flame relay responsive to a flame detector for providing an indication of flame in the supervised combustion chamber, a control relay, a magnetically operated lockout device, and a circuit for checking the continuity of the magnetically operated lockout device prior to energization of the control relay including in series with coil of the magnetically operated lockout device and the coil of the control relay.
  • Another object of the invention is to provide a novel and improved circuit arrangement for use in combustion supervision systems for checking in a coordinated, reliable manner the proper operation of lockout and flame detector apparatus prior to initiation of the fuel burning sequence.
  • combustion supervision apparatus for use in a combustion supervision system that includes a fuel control element, an ignition control element, a scheduler for operating components of the combustion control system to provide in sequence an initial (typically a purge) interval, an ignition interval, and a combustion interval; a flame detector; and circuitry responsive to the flame detector for providing an indication of the flame condition in the supervised combustion chamber.
  • the apparatus further includes a circuit for checking the continuity of an instantaneous operating lockout device that includes in series the actuator of the lockout device and the coil of a control relay.
  • the apparatus further includes a second circuit for maintaining the control relay energized including a first set of normally open control relay contacts connected in parallel with the series circuit of the lockout coil, and a first set of scheduler controlled contacts; a third circuit for checking the response of the flame detector prior to commencement of the ignition interval including normally open contacts controlled by the flame relay, and the series connection of a second set of scheduler controlled contacts and a second set of normally open control relay contacts connected in parallel with the series circuit of the first set of scheduler controlled contacts and the control relay coil; and a fourth circuit for checking the response of the flame detector after the ignition interval including the series connection of normally closed flame relay contacts and a third set of scheduler controlled contacts connected in parallel with the series circuit of the normally closed flame relay contacts and the second scheduler controlled contacts.
  • the lockout device is magnetically operated
  • the actuator includes a coil
  • the impedance of the control relay coil is at least four times the impedance of the lockout coil
  • the instantaneously operative lockout device requires manually resetting after tripping
  • the scheduler includes a timer motor and a series of cams for operating the scheduler controlled contacts.
  • Apparatus in accordance with the invention provides instantaneous lockout operation; electrical continuity of the lockout actuator is checked initially; and a condition for checking that a false flame signal is not present is maintained throughout the purge cycle.
  • the lockout and control relay coil circuits are connected in parallel so that failure condition which would trip the lockout device would not short out the control relay coil.
  • a momentary flame detection signal at any time in the initial interval will cause a safety shutdown and a momentary loss of flame after the ignition interval will also cause a safety shutdown.
  • both the lockout and control relay circuits are deenergized and the system is locked out until the lockout device is manually reset.
  • FIG. 1 is a schematic diagram of a combustion control system constructed in accordance with the invention.
  • FIG. 2 is a timing diagram indicating the operation of the scheduler employed in the system shown in FIG. 1.
  • the system shown in FIG. 1 includes terminals 10, 12 for connection to a volt source of AC electrical power.
  • a limit control 14 such as a low water switch, an operating control 16, such as a thermostat, and a running interlock 18 that closes in response to operation of a blower 20.
  • the circuit also includes a scheduler in the form of timer 22, an ignition control device 24, a pilot fuel control device 26, a main fuel control device 28, an alarm device 30, and a flame sensor 32.
  • the flame sensor 32 applies signals through flame detector circuitry 34, for example of the type shown in copending application Ser. No.
  • Flame relay 36 controls contacts 36-1-36b-3 that are open when flame relay coil 36 is deenergized and contacts 36-4 that are closed when flame relay coil 36 is deenergized.
  • the circuitry also includes a control relay coil 38 that controls normally open contacts 38-1-38-3 and normally closed contact 38-4; and lockout coil 40 that controls normally closed contact 40-1 and normally open contact 40-2.
  • Contacts 40-1 and 40-2 are spring loaded and when full line voltage is applied across coil 40, a lockout latch is released, immediately opening contacts 40-1 and closing contacts 40-2. This lockout device is manually reset by pushing its reset button to relatch contacts 40-1 and 40-2 in the position shown in FIG. 1.
  • Timer 22 controls a series of sixteen contacts that at time zero of timer 22 are in the position shown in FIG. 1.
  • the timing diagram of FIG. 2 shows the scheduler cycle of operation, that cycle having a duration seconds, and indicates the times at which the conditions of the contacts change.
  • a low fire interlock 50 is connected across contacts 22-13 and a control circuit including resistor 52, capacitor 54, and diode 56 is connected to the flame sensor electronics 34.
  • contacts 38-1 38-3 close and contacts 38-4 open.
  • the closing of contacts 38-1 completes a circuit to operate the timer motor 22 through contacts 22-13, 22-14, and 22-15.
  • contacts 22-12 close, energizing blower motor 20 to initiate a purge cycle and running interlock 18 closesas a result of airflow in the combustion chamber.
  • contacts 22-9 open, interrupting the energizing circuit for control relay coil 38 through lockout coil 40 so that coil 38 can be maintained energized only through its holding contacts 38-3 and running interlock 18.
  • slow make, quick break contacts 22-10 close, completing a circuit in parallel with quick make, slow break contacts 22-12.
  • the purge interval continues until timer time 90 seconds at which time contacts 22-5 (in series with pilot fuel control 26) close; damper control contacts 22-6 (not shown in FIG. 1) open; and contacts 22-16 open, removing flame relay contacts 36-1 from the circuit and terminating the check for false flame indication prior to ignition.
  • the lockout coil 40 will be energized through contacts 36-] and produce a lockout condition immediately on any false flame signal causing even momentary pickup of flame relay 36.
  • contacts 22-4 open disconnecting capacitor 54 from a charging circuit, and contacts 22-3 close, connecting the charged capacitor 54 through resistor 52 and diode 56 to apply a pseudo flame signal to the flame electronics 34 to cause energization of flame relay 36 even though no.flame is present in the combustion chamber.
  • flame relay 36 is held in solely by the signal from capacitor 54 which is discharging. With the energization of flame relay coil 36, contacts 36-1 36-3 close and contacts 36-4 open.
  • timer contacts 22-13 open toprovide a check on the position of the damper via the low fire interlock 50 which maintains timer motor 22 running if the damper is in low fire position. if the low fire interlock is not closed, the timer stops. As soon as the interlock closes the timer resumes its cycle.
  • timer contacts 22-11 close and a signal is applied through the running interlock 18, contacts 38-3, flame relay contacts 36-3, timer contacts 22-11 and 22-2 to energize the ignitiondevice 24 and through contacts 22-5 to operate the pilot fuel control 26 to admit pilot fuel to the combustion chamber.
  • the pilot fuel must be ignited and flame sensed by detector 32 prior to 106 seconds when contacts 22-3 reopen. If the program should stop (due to timer motor failure) with contacts 22-3 closed, the pseudo flame signal will be on as long as capacitor 54 has sufficient charge, typical times being in the range of 15 to 30 seconds. If flame is not sensed, relay 36 drops out, opening contacts 36-1 36-3 and terminating ignition.
  • contacts 36-[ 36-3 are held in by the energized flame relay coil 36. Pilot ignition terminates at 105 seconds with the opening of contacts 22-2, deenergizing ignition control 24. At 106 seconds contacts 22-3 open, terminating the pseudo flame signal, and contacts 22-4 close.
  • timer contacts 22-14 open for two seconds to enable pilot flame to be checked by removing the jumper 58 across contacts 22-14.
  • contacts 22-8 open so that the flame sensor electronics 34 remain energized only through a circuit completed by flame relay contacts 36-2; timer contacts 22-7 close completing a circuit between flame relay contacts 36-4 and control relay contacts 38-2, preparing a circuit for energization of lockout coil 40 should the flame relay become deenergized; and contacts 36-4 reclose.
  • the flame detector 32 must now be detecting the presence of 7 main flame to keep flame relay 36 energized.
  • Contacts 22-6 (the damper control contacts) also close at 121 seconds. At 130 seconds, contacts 22-15 open, deenergizing timer motor 22. The ignition cycle is finished and the burner system operates until a normal or safety shutdown occurs.
  • a normal shutdown occurs when limit control 14, operating control 16, or running interlock 18 opens, or a power interruption occurs. Any one of these events deenergizes control relay coil 38 and contacts 38-4 close starting timer motor 22. Timer contacts 22-15 close again at 135 seconds time; at Mo seconds contacts 22-1, 22-2, 22-7, 22-8, 22-11, 22-12, and 22-16 are reset preparatory for initiation of another combustion sequence; and at 150 seconds timer contacts 22-10 open deenergizing the timer motor and contacts 22-9 close. The control is ready for another ignition cycle.
  • a safety shutdown occurs whenever a false flame detection condition occurs during the purging cycle (actually from the time control relay 38 is energized at the start of the cycle until timer contacts 22-16 open (90 seconds into the cycle)); or when the. flame detector 32 or the amplifier electronics 34 fails to indicate pilot or main burner flame after contacts 22-7 close (1 10 seconds into the cycle).
  • a continuity path is established through coil 40, flame relay contacts 36-1, timer contacts 22-16, control relaycontacts 38-2, and lockout switch contacts 40-1. Should the flame relay contacts 36-1 close, full line power is immediately applied across coil 40 tripping the lockout latch and opening lockout contacts 40-1 to deenergize both lockout coil 40 and control relay coil 38. Lockout contacts 40-2 also close energizing alarm 30.
  • timer contacts 22-12 have closed (at timer 5 seconds)
  • the timer motor will continue to operate until contacts 22-10 open at seconds.
  • the ignition and fuel control components 24, 26 and 28 will not be energized as controlrelay contacts 38-3 are open.
  • the lockout switch 40 must be manually reset by pushing its reset button.
  • the invention provides a combustion control system in which instantaneous lockout occurs in response to a false flame signal during the purge interval and similarly instantaneous lockout occurs in response to a flame failure signal after flame should have been established in the combustion chamber.
  • the circuitry is established through limit controls, operating controls and running controls and opening of any of those controls will cause the system to shut down in safe condition while reset of the circuitry including a delay before a further combustion request will be respected and further including a purge cycle in response to such request.
  • Combustion supervision apparatus for use in a combustion control system that includes a fuel control element; an ignition control element; a scheduler for operating components of the combustion control system to provide an initial interval, an ignition interval and a combustion interval; and a flame detector,
  • said combustion supervision apparatus including a flame relay responsive to said flame detector for providing an indication of flame in the supervised combustion chamber, a control relay, a magnetically operated lockout device,
  • a first circuit for checking the continuity of said magnetically operated lockout device including in series the coil of said magnetically operated lockout device, normally closed contacts controlled by said flame relay, a first set of scheduler controlled contacts, the coil of said control relay and normally closed contacts controlled by said lockout device;
  • a second circuit for maintaining said control relay energized after the continuity of said lockout device has been checked including a first set of normally open control relay contacts connected in parallel with the series circuit of said lockout coil, said normally closed flame relay contacts, and said first set of scheduler controlled contacts,
  • a third circuit for checking the response of said flame detector prior to commencement of said ignition interval including the series connection of normally open contacts controlled by said flame relay, a second set of scheduler controlled contacts and a second set of normally open control relay contacts connected in parallel with the series circuit of said first set of scheduler controlled contacts and said control relay coil, and
  • a fourth circuit for checking the response of said flame detector after said ignition interval including the series connection of normally closed contacts controlled by said flame relay and a third set of scheduler controlled contacts connected in parallel with the series circuit of said normally open flame relay contacts and said second set of scheduler controlled contacts.
  • said lockout device includes a latch which holds said normally closed lockout contacts closed and energization of said lockout coil releases said latch and allows said normally closed lockout contacts to open instantaneously.
  • said scheduler includes a timer motor and a series of cams for operating said scheduler controlled contacts.
  • Combustion supervision apparatus including a flame relay responsive to-a flame detector for providing an indication of flame in the supervised combustion chamber, a control relay, an instantaneously operative magnetically operated lockout device, and a circuit for checking the continuity of said magnetically operated lockout device prior to energization of said control relay including in series the coil of said magnetically operated lockout device and the coil of said control relay.
  • Combustion supervision apparatus including a flame relay responsive to a flame detector for providing an indication of flame in the supervised combustion chamber, a control relay, a magnetically operated lockout device, a circuit for checking the continuity of said magnetically operated lockout device prior to energization of said control relay including in series the coil of said magnetically operated lockout device and the coil of said control relay, a scheduler for operating components of the combustion control system to provide in sequence an ignition interval and a combustion interval, a first circuit for checking the response of said flame detector prior to commencement of said ignition interval including the series connection of normally open contacts controlled by said flame relay and a first set of scheduler controlled contacts'connected in parallel with said control relay coil, and a second circuit for checking the response ofsaid flame detector after said ignition interval including the series connection of normally 6 closed contacts controlled by said flame relay and a second set of scheduler controlled contacts connected in parallel with the series circuit of said normally open flame relay contacts and said first set of scheduler controlled contacts.
  • Combustion supervision apparatus for use in a combustion control system that includes a fuel control element; an ignition control element; a scheduler for operating components of the combustion control system to provide an initial interval, an ignition interval and a combustion interval; and a flame detector,
  • said combustion supervision apparatus including a flame relay responsive to said flame detector for providing an indication of flame in the supervised combustion chamber, a control relay, a lockout device,
  • a first circuit for checking the continuity of said lockout device including in series the actuator of said lockout device, and a first set of scheduler controlled contacts, the coil of said control relay and normally closed contacts controlled by said lockout device; a second circuit for maintaining said control relay energized after the continuity of said lockout device has been checked including a first set of normally open control relay contacts connected in parallel with the series circuit of said lockout actuator and said first set of scheduler controlled contacts,
  • a third circuit for checking the response of said flame detector prior to commencement of said ignition interval including the series connection of normally open contacts controlled by said flame relay, a second set of scheduler controlled contacts and a second set of normally open control relay contacts connected in parallel with the series circuit of' said first set of scheduler controlled contacts and said control relay coil, and
  • a fourth circuit for checking the response of said flame detector after said ignition interval including the series connection of normally closed contacts controlled by said flame relay and a third set of scheduler controlled contacts connected in parallel with the series circuit of said normally open flame relay contacts and said second set of scheduler controlled contacts.
  • said lockout device includes a latch which holds said normally closed lockout contacts closed and energization of said actuator releases said latch and allows said normally closed lockout contacts to open instantaneously.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Regulation And Control Of Combustion (AREA)
  • Control Of Combustion (AREA)
US3644748D 1970-08-03 1970-08-03 Combustion supervision apparatus Expired - Lifetime US3644748A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US6022970A 1970-08-03 1970-08-03

Publications (1)

Publication Number Publication Date
US3644748A true US3644748A (en) 1972-02-22

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US3644748D Expired - Lifetime US3644748A (en) 1970-08-03 1970-08-03 Combustion supervision apparatus

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US (1) US3644748A (de)
BE (1) BE770631A (de)
CA (1) CA945654A (de)
CH (1) CH535920A (de)
DE (1) DE2138869B2 (de)
FR (1) FR2103931A5 (de)
GB (1) GB1354319A (de)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4101258A (en) * 1977-05-25 1978-07-18 Honeywell Inc. Fuel burner sequencing device with safety checking means
US4451226A (en) * 1983-01-10 1984-05-29 Honeywell Inc. Flame safeguard sequencer having safe start check
US4451225A (en) * 1983-01-31 1984-05-29 Honeywell Inc. Flame safeguard sequencer having interlock checking means
US4521120A (en) * 1983-09-15 1985-06-04 The United States Of America As Represented By The Secretary Of Agriculture Forest fire rate of spread with timers method
EP0849535A1 (de) * 1996-12-20 1998-06-24 Satronic Ag Verfahren sowie Vorrichtung zur Steuerung eines Brenners, insbesondere eines Gas- oder Oelbrenners
US20150330665A1 (en) * 2014-05-14 2015-11-19 Emerson Electric Co. Systems and methods for controlling gas powered appliances
US20150330663A1 (en) * 2014-05-14 2015-11-19 Emerson Electric Co. Systems and methods for controlling gas powered appliances
CN108700437A (zh) * 2016-04-28 2018-10-23 西门子股份公司 用于确定过程自动化中的过程变量的现场仪器

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2138173A (en) * 1983-03-22 1984-10-17 Peerless Stampings Ltd A control circuit for use with a fuel control valve

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4101258A (en) * 1977-05-25 1978-07-18 Honeywell Inc. Fuel burner sequencing device with safety checking means
FR2401383A1 (fr) * 1977-05-25 1979-03-23 Honeywell Inc Moyens de mise en sequence pour bruleur a petrole
US4451226A (en) * 1983-01-10 1984-05-29 Honeywell Inc. Flame safeguard sequencer having safe start check
US4451225A (en) * 1983-01-31 1984-05-29 Honeywell Inc. Flame safeguard sequencer having interlock checking means
US4521120A (en) * 1983-09-15 1985-06-04 The United States Of America As Represented By The Secretary Of Agriculture Forest fire rate of spread with timers method
EP0849535A1 (de) * 1996-12-20 1998-06-24 Satronic Ag Verfahren sowie Vorrichtung zur Steuerung eines Brenners, insbesondere eines Gas- oder Oelbrenners
CH691193A5 (de) * 1996-12-20 2001-05-15 Satronic Ag Verfahren sowie Vorrichtung zur Steuerung eines Brenners, insbesondere eines Gas- oder Oelbrenners.
US20150330665A1 (en) * 2014-05-14 2015-11-19 Emerson Electric Co. Systems and methods for controlling gas powered appliances
US20150330663A1 (en) * 2014-05-14 2015-11-19 Emerson Electric Co. Systems and methods for controlling gas powered appliances
US9568196B2 (en) * 2014-05-14 2017-02-14 Emerson Electric Co. Systems and methods for controlling gas powered appliances
US9574793B2 (en) * 2014-05-14 2017-02-21 Emerson Electric Co. Systems and methods for controlling gas powered appliances
CN108700437A (zh) * 2016-04-28 2018-10-23 西门子股份公司 用于确定过程自动化中的过程变量的现场仪器
CN108700437B (zh) * 2016-04-28 2021-01-15 西门子股份公司 用于确定过程自动化中的过程变量的现场仪器

Also Published As

Publication number Publication date
FR2103931A5 (de) 1972-04-14
DE2138869A1 (de) 1972-02-10
DE2138869B2 (de) 1973-06-20
GB1354319A (en) 1974-06-05
CA945654A (en) 1974-04-16
CH535920A (de) 1973-04-15
BE770631A (fr) 1971-12-01

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