US3711237A - Ignition and control devices for fuel burners - Google Patents

Ignition and control devices for fuel burners Download PDF

Info

Publication number
US3711237A
US3711237A US00168292A US3711237DA US3711237A US 3711237 A US3711237 A US 3711237A US 00168292 A US00168292 A US 00168292A US 3711237D A US3711237D A US 3711237DA US 3711237 A US3711237 A US 3711237A
Authority
US
United States
Prior art keywords
accordance
circuit
ignition
frequency
capacitor
Prior art date
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
Application number
US00168292A
Other languages
English (en)
Inventor
E Jaulmes
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
MBK Industrie SA
Original Assignee
Ateliers de la Motobecane SA
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Ateliers de la Motobecane SA filed Critical Ateliers de la Motobecane SA
Application granted granted Critical
Publication of US3711237A publication Critical patent/US3711237A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N5/00—Systems for controlling combustion
    • F23N5/02—Systems for controlling combustion using devices responsive to thermal changes or to thermal expansion of a medium
    • F23N5/12—Systems for controlling combustion using devices responsive to thermal changes or to thermal expansion of a medium using ionisation-sensitive elements, i.e. flame rods
    • F23N5/123—Systems for controlling combustion using devices responsive to thermal changes or to thermal expansion of a medium using ionisation-sensitive elements, i.e. flame rods using electronic means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23Q—IGNITION; EXTINGUISHING-DEVICES
    • F23Q3/00—Igniters using electrically-produced sparks
    • F23Q3/004—Using semiconductor elements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
    • F02P17/00—Testing of ignition installations, e.g. in combination with adjusting; Testing of ignition timing in compression-ignition engines
    • F02P17/12—Testing characteristics of the spark, ignition voltage or current
    • F02P2017/125—Measuring ionisation of combustion gas, e.g. by using ignition circuits
    • F02P2017/126—Measuring ionisation of combustion gas, e.g. by using ignition circuits for burners
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N2227/00—Ignition or checking
    • F23N2227/36—Spark ignition, e.g. by means of a high voltage
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N2231/00—Fail safe
    • F23N2231/04—Fail safe for electrical power failures
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N2239/00—Fuels
    • F23N2239/06—Liquid fuels

Definitions

  • the sub ect matter of the d1sclosure relates to a control device which is an improvement on French Pat.
  • Forelgn Appl'catlon Pnonty Data No. 1,598,786 wherein the ignition and detection of March 9, 1971 France ..7108138 the Preseme or absence Of a flame are both effected at a relatively low frequency (less than 1 Hz)
  • means are provided to [51] Int. Cl ..F23n 5/12 effect the ignition at a relatively higher frequency
  • the principle on which the detection is based is the difference, in conditions of ionization and non-ionization, in the value of the damping coefficient, in a transient mode, of a very small third coil which, with a condenser connected in parallel, forms a damped oscillating circuit.
  • a pulse generating means is operable to deliver to the single electrode a succession of spark-producing pulse trains, the pulse trains being separated from one another by intervals which are longer than the duration of each train, a detector means detects the presence or absence of a flame when a spark appears across the said gap, and there are means whereby, when ignition takes place, the pulse generating means changes over automatically to cause the production of sparks at a frequency substantially lower than the frequency of the pulses in the trains.
  • the frequency of the pulses in the pulse trains may be that of the main supply and the frequency of the sparks produced for detection purposes, once ignition has taken place, may not be greater than lI-Iz.
  • the interval between successive pulse trains when ignition is attempted allows the unburnt mixture to disperse in the atmosphere, to reduce risk of explosion.
  • the invention is also applicable to temperature regu- Iation, for example in heating systems, and it can also be applied in safety systems, in particular those which operate:
  • FIG. 1 illustrates diagrammatically the operation of currently employed devices
  • FIG. 2 illustrates diagrammatically the operation of the device described in the above-mentioned patent
  • FIG. 3 illustrates diagrammatically the operation of a device embodying the present invention
  • FIG. 4 shows a circuit similar to that shown in the above-mentioned patent
  • FIGS. 5 to 12 show oscillograms illustrating the method of functioning of this device
  • FIG. 13 is the overall circuit of a device embodying the present invention.
  • FIG. 14 is a circuit for a variant intended particularly for igniting heavy hydrocarbons
  • FIG. 15 shows the synchronization signal used in the latter
  • FIG. 16 shows the pilot signal
  • FIG. 17 shows the interruptions of the inductive current.
  • a negative potential is therefore applied to the base of T, during the entire oscillation period, which blocks it and produces on its collector a rectangular signal whose duration is proportional to the oscillation period t (see FIG. 7).
  • This signal allows the condenser C to be charged through two resistances R and R according to the time constant (R R, C If there is no flame, and consequently t is greater than this time constant, the voltage across the terminals of the condenser C, reaches the threshold of a junction transistor T triggering this transistor (see FIG. 8), and producing a positive pulse across the terminals of a resistance R
  • FIGS. 9 to 12 which correspond respectively to FIGS.
  • the frequency of the series of sparks which is the supply frequency, is attained by means of a disc whose response threshold is reached when the two condensers C and C which are connected in series, are charged up to a voltage corresponding to this threshold.
  • the condenser C is charged by a rectifying diode D, and discharged by a thyristor T As shown in FIG. 3 a very satisfactory frequency for ignition is 50 Hz but other frequencies significantly greater than I I-lz may be applied.
  • the switching to the detection frequency is obtained by short circuiting the condenser C which is very small compared to the condenser C by means of an NPN transistor T
  • This transistor T is saturated when the condenser C, reaches the saturation threshold. This period is determined by the time constant R C, It is necessary to provide a voltage divider consisting of resistances R and R, such that the voltage across the condenser C, is prevented from reaching excessively high values.
  • the inductive train of sparks used for igniting heavy fuel products is obtained, as shown in FIG. 14, by derivin g a comparatively heavy current with the help of a resistance R
  • This current is passed, by means of a power transistor T in the primary coil N 1 of the ignition transformer.
  • the synchronization signal of this transistor is derived by means of a zener diode Zn and applied to the monostable integrated circuit CM.
  • This circuit acts through a transistor Ta to cause the power transistor T to become conductive at the beginning of a half sinewave of the supply voltage (this is the pilot signal shown in FIG. 16) and to block the power transistor T when the inductive current reaches its maximum (see FIG. 17).
  • the integrated circuit CM is locked when the condenser C is charged and the transistor T, is saturated.
  • the detection sparks can be obtained at low frequency over the circuit R C diac.
  • the pulses used for attempted reignition can also be obtained at the terminals of the circuit N C.
  • the detection circuit naturally indicates absence of flame. It is therefore necessary to lock the safety system during the ignition period. This is obtained by short circuiting the condenser C by means of a PNP transistor T as soon as the voltage is applied and by causing the transistor T to be unblocked progressively before the end of the ignition period.
  • a diode D is interposed in series with the base of the transistor T the anode-cathode path of the diode D being conductive as soon as voltage is applied. As soon as the potential across the condenser C is sufficient to block the diode D this blocks the transistor T allowing the condenser C to charge up.
  • the pulses indicating absence of flame derived from the terminals of the resistance R are integrated through the diode D in a condenser C
  • the transistor T saturates opening a relay RL (in part D of FIG. 13) having two contacts C RL and C RL. This interrupts the control sparks and the condenser C discharges slowly, until the transistor T becomes blocked again, whereupon the relay RL closes, producing a fresh sequence of sparks at the ignition electrode A1.
  • the counting circuit comprises a non-locked detection circuit consisting of a transistor T and a unijunction transistor T During the ignition phase the circuit produces a sequence of pulses across a resistance R The pulses are integrated in a condenser C by way of a diode D3. A transistor T connected in series with a resistance R becomes saturated, charging the condenser C Each time the relay RL closes and a fresh sequence of sparks occurs, the condenser C charges up step by step until the threshold of the uni-junction transistor T is reached.
  • the transistor T As soon as this threshold is reached, the transistor T is triggered. A pulse appears on the terminals of the resistance R The thyristor T is triggered, short circuiting the relay RL and so ensuring that it remains open. Consequently, the device can be returned to zero only by an intervention by the operator. If the fuel ignites at the first attempt, or at the second attempt, the control spark occurs in an ionized medium, and consequently no pulse appears across the resistances R and R and the process of reignition does not take place.
  • the safety device which comes into operation when an electrode short circuits, or when there is an ignition failure (part C of FIG. 13).
  • the detection signal derived from the terminals of the circuit N;,, C is also applied, over a condenser C to a further detection circuit which is essentially similar to the circuit shown in part B of FIG. 13, except that the means for locking during the ignition phase are omitted.
  • the time constant is chosen such that in the case of an ionized medium, the uni-junction transistor T delivers a pulse to the terminals of a resistance R
  • the condenser C charges up over the resistance R A transistor T connected in parallel, partially discharges this condenser at each detection spark.
  • the temperature control which will now be described (see part D of FIG. 13) is carried out by means of a relaxation oscillator comprising a uni-junction transistor T
  • the high frequency pulses appearing across a resistance R are integrated in the condenser C by way of a diode D
  • the transistor T becomes saturated, closing the main relay RL and opening the electrovalve EV for the fuel.
  • a negative temperature coefficient resistance CTN decreases in value until the saturation current of the transistor T is attained, whereupon the circuit ceases to oscillate and consequently the transistor T becomes blocked, opening the relay RL.
  • FIG. 13 shows a pressure controlled contact P, which interrupts the general feed to the system as soon as the gas pressure drops.
  • the low voltage required by the system is provided by a circuit (the part F of FIG. 13) which has no input transformer, the isolation from the supply circuit being provided by the ignition transformer.
  • the circuit has a condenser C connected in series with a diode bridge D The filtering is done by a condenser C
  • a resistance R limits the short circuit current when the system is in the safety condition.
  • An ignition and safety device for burners consuming hydrocarbon fuels or other combustible fluid fuels comprising: a single electrode for igniting the fuel positioned to form a spark gap between itself and the burner; pulse-generating means operable to deliver to the electrode a succession of spark-producing pulse trains, the pulse trains being separated from one another by intervals which are longer than the duration of each train; detector means for detecting the presence of absence of a flame when a spark occurs across the said gap; and means whereby when ignition takes place the pulse-generating means changes over automatically to cause the production of sparks at a frequency substantially lower than the frequency of the pulses in the said first mentioned trains.
  • detector means includes means responsive to a predetermined number of the said pulse trains without ignition taking place to close and block a fuel valve in such a manner that manual intervention is required to reopen it.
  • a device in accordance with claim 1 including a pressure-controlled device responsive to a failure of the fuel supply to cut the electrical supply to the circuit and operative to re-establish the electrical supply automatically when the fuel supply is re-established.
  • the detector means includes means responsive to a shortcircuit condition between the electrode and the burner to close a fuel valve in such a manner that manual intervention is required to re-open it.
  • the detector means includes means responsive to an abnormally high burner temperature to close a fuel valve in such a manner that manual intervention is required to open it.
  • a device in accordance with claim 1 in which the individual sparks in the said trains of sparks are generated at the frequency of the alternating current supply by means of a circuit including a threshold diode connected in series with the gate of a discharge thyristor.
  • a device in accordance with claim 6, including a power transistor connected to interrupt the current flowing through the primary coil of an ignition transformer and thereby to produce an inductive spark having a duration of at least 1,500 microseconds, the power transistor being biased by a monostable circuit.
  • a device in accordance with claim 4 including means to count the attempts to re-ignite the fuel comprising an integrating capacitor which is charged, one step at a time, with each train of pulses, and a transistor operative when this capacitor is charged to its threshold level to energize a relay which closes a fuel valve.
  • a device in accordance with claim 7 including a circuit having a capacitor which is charged over a resistor, the capacitor being partially discharged with each low-frequency detection spark when the burner is functioning normally, and a transistor responsive to the charge on the said capacitor and operable when the detection spark fails to take place or when there is a short circuit in the electrode circuit, to close the said fuel valve.
  • a device in accordance with claim 8 including a circuit having a capacitor which is charged over a resistor, the capacitor being partially discharged with each low-frequency detection spark when the burner is functioning normally, and a transistor responsive to the charge on the said capacitor and operable when the detection spark fails to take place or when there is a short circuit in the electrode circuit, to close the said fuel valve.
  • a device in accordance with claim 10 including means for detecting an abnormal increase in the burner temperature comprising a resistance having a positive temperature coefficient, in a resistance-capacitance circuit such that in the case of an abnormal increase in temperature the voltage across a capacitance fails to reach the threshold of a transistor to the control electrode of which the capacitor is connected.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Control Of Combustion (AREA)
  • Ignition Installations For Internal Combustion Engines (AREA)
US00168292A 1971-03-09 1971-08-02 Ignition and control devices for fuel burners Expired - Lifetime US3711237A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7108138A FR2128949A5 (ko) 1971-03-09 1971-03-09

Publications (1)

Publication Number Publication Date
US3711237A true US3711237A (en) 1973-01-16

Family

ID=9073210

Family Applications (1)

Application Number Title Priority Date Filing Date
US00168292A Expired - Lifetime US3711237A (en) 1971-03-09 1971-08-02 Ignition and control devices for fuel burners

Country Status (7)

Country Link
US (1) US3711237A (ko)
JP (1) JPS5310293B1 (ko)
CA (1) CA981356A (ko)
DE (1) DE2136556A1 (ko)
ES (1) ES393321A1 (ko)
FR (1) FR2128949A5 (ko)
NL (1) NL7111128A (ko)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4384845A (en) * 1981-07-27 1983-05-24 Honeywell Inc. Fail safe digital fuel ignition system
EP0798514A2 (en) * 1996-03-02 1997-10-01 Imi Pactrol Limited Improvements relating to spark igniters
US20070224557A1 (en) * 2006-03-22 2007-09-27 I-Hua Huang Controller for re-igniting
US20100134795A1 (en) * 2008-11-28 2010-06-03 Shimadzu Corporation Flame atomic absorption spectrophotometer
EP3591293A4 (en) * 2017-02-28 2020-06-10 Mitsubishi Heavy Industries Marine Machinery & Equipment Co., Ltd. BOILER, BOILER SYSTEM AND BOILER OPERATING METHOD

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USPP12295P2 (en) * 1999-06-01 2001-12-18 Florfis Ag Geranium plant named ‘Fiscoral’
USPP12225P2 (en) 1999-06-01 2001-11-27 Florfis Ag Geranium plant named ‘Fislamda’

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3377125A (en) * 1966-06-16 1968-04-09 American Gas Ass Electrical ignition system for gaseous fuel burners and the like
US3384440A (en) * 1964-03-24 1968-05-21 Lab D Electronique Et D Automa Ignition devices
US3405998A (en) * 1967-06-26 1968-10-15 Fenwal Inc Ignition and flame monitoring control apparatus for fuel burners
US3614280A (en) * 1968-12-27 1971-10-19 Tokyo Gas Co Ltd Ignition and flame detection system utilizing a single electrode

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3384440A (en) * 1964-03-24 1968-05-21 Lab D Electronique Et D Automa Ignition devices
US3377125A (en) * 1966-06-16 1968-04-09 American Gas Ass Electrical ignition system for gaseous fuel burners and the like
US3405998A (en) * 1967-06-26 1968-10-15 Fenwal Inc Ignition and flame monitoring control apparatus for fuel burners
US3614280A (en) * 1968-12-27 1971-10-19 Tokyo Gas Co Ltd Ignition and flame detection system utilizing a single electrode

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4384845A (en) * 1981-07-27 1983-05-24 Honeywell Inc. Fail safe digital fuel ignition system
EP0798514A2 (en) * 1996-03-02 1997-10-01 Imi Pactrol Limited Improvements relating to spark igniters
EP0798514A3 (en) * 1996-03-02 1999-04-21 Pactrol Controls Limited Improvements relating to spark igniters
US20070224557A1 (en) * 2006-03-22 2007-09-27 I-Hua Huang Controller for re-igniting
US20100134795A1 (en) * 2008-11-28 2010-06-03 Shimadzu Corporation Flame atomic absorption spectrophotometer
US8294893B2 (en) * 2008-11-28 2012-10-23 Shimadzu Corporation Flame atomic absorption spectrophotometer
EP3591293A4 (en) * 2017-02-28 2020-06-10 Mitsubishi Heavy Industries Marine Machinery & Equipment Co., Ltd. BOILER, BOILER SYSTEM AND BOILER OPERATING METHOD

Also Published As

Publication number Publication date
DE2136556A1 (de) 1972-09-21
JPS5310293B1 (ko) 1978-04-12
FR2128949A5 (ko) 1972-10-27
CA981356A (en) 1976-01-06
NL7111128A (ko) 1972-09-12
ES393321A1 (es) 1973-08-16

Similar Documents

Publication Publication Date Title
US4303385A (en) Direct ignition system for gas appliance with DC power source
US3681001A (en) Fluid fuel igniter control system
US3902839A (en) Electronic pilot ignition and flame detection circuit
US3425780A (en) Fluid fuel igniter control system
US3894273A (en) Spark ignition circuit for gas burners
US3947220A (en) Fuel ignition control arrangement
US3975136A (en) Burner control system
US3449055A (en) Burner control apparatus with prepurge timing
US3377125A (en) Electrical ignition system for gaseous fuel burners and the like
US3711237A (en) Ignition and control devices for fuel burners
US4298335A (en) Fuel burner control apparatus
US3832123A (en) Burner control system
US3318358A (en) Burner igniter system
US4111639A (en) Proven pilot fuel ignition system with sampling flame sensor
US4662838A (en) Fuel burner control system
US3447880A (en) Control system for fluid fuel burners
US3726630A (en) Flame ignition
US4325689A (en) Automatic reset control for direct spark ignition systems
US3847533A (en) Flame ignition and supervision system
US3441356A (en) Pulsed spark gas ignition and fuel control system
US4459097A (en) Fuel burner control apparatus
US3384439A (en) Pulsed spark gas ignition and flame monitoring system
US3955910A (en) Self-checking automatic pilot fuel ignition system
US4299557A (en) Fuel burner control circuit
US3734676A (en) Electrically energizable control system for a fuel burner