FR2513743A1 - METHOD OF MONITORING FLAME OF OIL AND GAS - Google Patents

Abstract

OIL AND GAS FLAME MONITORING PROCEDURE WITH AN AUTOMATIC HEATING DEVICE 1 FOR THE COMBUSTION OF OIL OR GASEOUS FUELS OF YOUR CHOICE. THE AUTOMATIC HEATING DEVICE 1 CONTAINS, IN ADDITION TO A PROGRAMMER 2, A SINGLE FLAME CONTROLLER 4, INFLUENCED BY TWO FLAME DETECTORS IN SERIES, A UV CELL 5 AND A PHOTORESISTOR 6. A SWITCH 12 SHUNTS THE PHOTORESISTOR 6 FOR MONITORING THE PHOTORESISTOR 6. A GAS FLAME, BUT REMAINS DURING OIL OPERATION.

Description

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  The present invention relates to a method of monitoring flames of oil and gas with an automatic heating device for the

  burning fuel oil or gas fuels of your choice.

  The current methods of burner monitoring differ in the nature of the flame detector and the corresponding flame controller or its amplifier. For oil flames, essentially photoresistors are

  spectral sensitivity and allow economic production to be

  However, the low luminosity of the gas flames

  not for photoresistance monitoring and ionisation probes have been proven, which are in principle also usable for fuel oil flames, but are not suitable in the long term as a result

  coking in these flames.

  Sensors sensitive to UV radiation, called UC cells

  after, are equally suitable for both types of flames; they pre-

  however feel the disadvantage of reacting to the arc of the spark of allu-

  mage and are likely to produce significant cuts in the case of braleu-s

  fuel oil running with a lead time on ignition.

  The sharp increase in the price of heating oil and the current rapid change in the oil and gas price ratio have created a demand for

  burner models that are equally suitable for both

  The operator of an installation can thus always use the cheapest fuel, depending on market conditions in the field.

Energy.

  The types of detectors described, photoresistances for fuel oil flames and UV cells for flames of gas, also required

  so far two different flame controllers.

  The invention relates to a method which, in the monitoring of a fuel oil or gas flame of choice, makes it easy to replace the two flame controllers currently required by a single flame controller, so far only suitable for for UV cells, for the distinction between UV and visible radiation, and applicable as a result

  also to oil burners with a long lead time on ignition.

  According to an essential characteristic of the invention, the flame detectors consist of a UV cell and a connected photoresistor

  in series and inserted into a detector circuit which acts on a con-

  tr 6 of their unique flame; and both flame detectors are subject

  common to the same radiation, the photoresistor being shunted electrically

  only during the monitoring of a gas flame.

  Other features and advantages of the invention will be better

  understood using the following detailed description of the process, including:

  the single figure represents the diagram.

  An automatic heating device 1 controls a burner, not shown, using elements that are not shown, such as engines of an oil pump and / or of an air blower, fuel valve, etc. The device automatic heating 1 contains a programmer 2,

  which feeds a detector circuit 3- The latter acts on a controller

  The flame detectors are constituted by a UV cell 5 and a photoresistor 6, connected in series and subjected in common to the same flame radiation, the photoresistor 6 being shunted electrically during the monitoring of a gas flame. The detector circuit 3 also contains a resistor 7 in series with the two

  flame detectors 5, 6, and whose voltage drop influences an ampli-

  indicator 8 in the flame controller 4 To do this, the inputs 9

  and amplifier 8 are connected in parallel with resistor 7.

  When the amplifier 8 is driven by the detector circuit, a flame relay 11 of the flame controller 4 switches on and signals the

  programmer 2 the presence of a flame.

  The photoresistor 6 can be shunted by a switch 12 It is last always closed during the monitoring of a gas flame,

  that is, the monitoring is then carried out only by

  lule UV 5 and that the photoresistor 6 is no longer active.

  On the other hand, the switch 12 is open while monitoring an oil flame, the UV cell 5 and the photoresistor 6 then being connected in series. Reacting to the ignition sparks, the cell M 5 would already signal a flame for these sparks. in the absence of the photoresistor 6 The latter must therefore be active at least during the ignition time, because its r 8 is during this time to prohibit engagement of the flame relay 11 by the UV cell 5 reacting to the

ignition sparks.

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  In the simplest embodiment, the switch 12 is advantageously

  consisting of a hand switch, built-in

  flame 4 and remains open as long as fuel oil is burned.

  With the current burns, the ignition is switched on from the beginning of the preliminary scan, when an oil flame is put into service.

  while for gas operation, ignition is only connected

  mediately before or simultaneously with the opening of the gas supply.

  Program switching is therefore also necessary - during a change in

  This is why it may be wise to mount the switch 12 in the programmer 2 and dispose of it by

  construction so that it is necessarily activated during the

  different start times for ignition on gas or fuel oil The fact that switch 12 is part of the programmer

  2 is indicated in this case in the figure by a straight line 13.

  In the case of flame controllers with a test blanking for the permanent self-checking of the flame detector, according to for example the Swiss patent NO 604 086, it suffices that only the UV cell 5 operates with test occultation. The photoresistor is of any kind. in the case of monitoring a gas flame and, when monitoring an oil flame, the series connection according to the invention of the flame detectors 5, 6 ensures intrinsic safety

  acquired, even for photoresistance 6 When the latter is short-

  switched on in operation, the flame is still monitored by the UV cell 5 operating with test concealment The short circuit then leads to a failure cut before the next commissioning, due to stray light during the advance time at ignition, because the cell W 5 detects the ignition sparks as a light A defect in the photoresistor 6 corresponding to an interruption produces a fault trigger at the end of the safety time, as well as

  during commissioning only in service.

  An assembly, which activates the photoresistor 6 only during the ignition time and the shunt for the rest of the time, is also advantageous in the case of a UV cell 5 operating with test concealment as previously indicated. This result can be obtained. help

  relay contact or switching contact of programmer 2.

  On the other hand, photoresistor 6 must never be shunted during operation with oil if the flame monitoring is carried out without the aforementioned test occultation. A UV cell 5 tending to present uncontrolled failures is not detected as long as the photoresistor 6 works correctly, but this is irrelevant in the assembly considered, because the photoresistor 6 ensures the flame detection A failure cut is triggered when a stray light is indicated by a photoresistor, whose resistance decreases for example, during the time of preliminary scan-o the UV cell 5 will start anyway as a result of the ignition spark interruptions are

detected anyway.

  The indicated method allows the switching of the flame control system on one fuel or the other by a single switching contact, which considerably simplifies the wiring of the equipment and increases the

reliability.

  In the case of a type of burner operating as well with fuel oil as with gas with the same ignition advance times and

  preliminary scanning, the operation of the switch 12 advantageously ensures

  the switching of the entire automatic heating device

  on one type of fuel or the other.

  Of course, various modifications can be made by those skilled in the art to the principle and to the devices which have just been described as non-limiting examples, without departing from the

framework of the invention.

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Claims (5)

claims   1 Method for monitoring flames of oil and gas with a provision   automatic heating system (1) for the combustion of oil or fuel   gaseous gases, said method being characterized in that the flame detectors are constituted by a UV cell (5) and a photo-   resistor (6), connected in series and inserted in a detection circuit   actuators (3) acting on a single flame controller (4); and the two flame detectors (5, 6) are subjected to the same radiation in common, the photoresistor (6) being electrically shunted during the monitoring of a gas flame.   Process according to Claim 1, characterized in that the photoresist   tance (6) is shunted by a switch (12).   3. Process according to claim 1, characterized in that the photoresist   tance (6) is active at least during the ignition duration during the over- vigilance of an oil flame.   4 Process according to claim 2, characterized in that the switch (12) is incorporated in a programmer (2) of the automatic heating device (1) and is necessarily actuated by the switching of the times   different ignition timing for gas and oil operation.   Method according to one of claims 1 or 4, characterized in that   in the case of flame control devices (4) with self-test   permanent monitoring of the flame detector, only the UV cell (5)   works with the occultation test.