FR2642507A1 - DEVICE FOR CONTROLLING THE COMBUSTION OF A BURNER - Google Patents

Abstract

Device characterized in that: - the reactor 8 is constituted by a tube connected to a fuel inlet 11 and a combustion air inlet 10; - The tube 8 is placed at least in part 12 in the flame 13 of the burner; the outlet of the tube beyond the zone 12 placed in the flame 13 is provided with the sensor 14. The invention relates to the regulation of combustion.

Description

"Device for controlling the combustion of a burner"

  The invention relates to a device for controlling the combustion of a burner, a device comprising a reactor receiving a combustible mixture depending on the fuel supplying the burner and a

  sensor for the products of combustion of the reactor.

  Such a device is already known according to the

patent FR 85 14 605.

  The present invention aims to develop

  per such a device, to facilitate the implementation and implementation on original burners or even on existing burners, and to promote

  also the regularity of operation and the reliability

control.

  For this purpose, the invention relates to a device

  the above type characterized in that:

  the reactor is constituted by a tube

  connected to a fuel inlet and an inlet of combustion air, - the tube is placed at least partly in the flame of the burner,

  - the exit of the tube beyond the planar zone

  in the flame, is equipped with the sensor.

  Since the reactor is made by a tube,

  we get inside it a good circulation

  we get inside it a good circulation

  tion of the fuel mixture and consequently a good

  avoiding combustion reaction with a recurrent combustion

  which solicits under these conditions in a

  the sensor and allowing a good regulation of the combustion carried out by the burner. The provision

  The control system is extremely simple to

  ple. Its mounting is also simple to perform both on new burners and on burners already installed since it is sufficient to make a stitching on the fuel line (gas) downstream of the stop valve and to place the formed part of the tube over there

loop in the area of the flame.

  This control device whose reaction zone is placed in the flame therefore works in conditions very similar to those of the flame and thus allows a particularly precise and faithful control. Although this control device, at least for the part placed in the flame, can be

  constituted by a tube having no particular shape

  re, it is interesting to make this part of the tube in the form of a loop or even several turns. The inlet of this tube forming the reactor is

  upstream of the flame holder while the

  part of this tube leads into the fireplace, at the level of the

  flame, for the evacuation of combustion products.

  According to another characteristic, the tube is made of a refractory material selected from the group consisting of steel with a high nickel content.

  and chromium and a ceramic material.

  According to another characteristic, the tube forming the reactor has inside means

facilitating combustion.

  These means facilitating combustion are advantageously catalysts, especially those based on

platinum, silver or palladium.

  According to another interesting feature

  the inner part of the tube is provided with asperities receiving the catalysts and forming points of

  heating facilitating and stabilizing the combustion of

lange in the reactor.

  According to one embodiment, the asperities

  consist of either point forms,

  continuous, or again by nets comparable to screw threads or by inserts placed at

  the inside of the tube and forming a support for the

talyseur.

  According to another characteristic, the

  rites are constituted by a tapping performed at

the inside of the tube.

  According to another characteristic, the means

  gas inlet and oxidizer and the sensor are so-

  killed in the vicinity of the flame holder.

  The present invention will be described in more detail with the aid of the accompanying drawings in which: FIG. 1 is a diagrammatic view of a

  burner equipped with a control device according to

vention.

  FIG. 2 is a sectional view of a first

  first embodiment of a reactor according to the invention.

tion.

  - Figure 3 is a sectional view of a se-

  cond embodiment of a reactor according to the invention

tion.

  According to FIG. 1, the combustion control device is intended for a burner 1 opening

  through a wall 2 in a firebox 3. The burner

  takes a fuel supply for example

  Zeux 4 equipped with a stop valve 5 opening on the

  the burner in front of the flame holder.

  burant is provided by a fan 7.

  The device according to the invention comprises a reactor formed of a tube 8 provided with a fuel supply 9 and a supply 10 of combustion air. The fuel supply 9 is made by a tap on the main pipe 4. This socket is connected by a small tube to the tube itself, 8 of the

  device. The small feeding tube 11 can

  wear a diaphragm or other means

  accurately finish the flow of fuel in the tube 11 relative to the fuel flow in the

tube 4.

  The tube 8 comprises a loop 12 placed at the level of the flame 13 which develops behind

  the flame holder 6. Combustible and Combustible Gases

  blowing flow in the tube 12 according to the arrow A. Following the loop 12 or more generally of the portion 12 of the tube 8 located in the flame 13, there is a

  sensor or probe 14 which is exposed to the combustion gases

  to analyze them. Finally, the tube ends with

  an outlet 15 which opens into the home.

  The tube 8 or at least its portion 12 placed in the flame 13 is made of a refractory material such as steel with a high content of nickel and chromium or a ceramic. The tube 12 can be smooth inside. It is advantageous, however,

  contains elements promoting the com-

  such as catalysts based on

platinum, silver or palladium.

  Thus, according to a first embodiment appearing in FIG. 2, which is a cross-sectional view of the tube portion 12, and here referred to as 12A, the inner shape of the tube has asperities or teeth 16 formed either by

  ad hoc training, either by means of

  step by step. These asperities constitute

  points of overheating. According to one variant, it is advantageous

  to coat the inside of the tube with a catalyst layer schematized by the dotted line 16. In some cases, it is also possible to limit the catalyst to coating only the ends of the asperities.

or protruding parts.

  In this embodiment of tube 12A, the

  outside temperature of the tube 12A is equal to the time

  flame temperature whereas at the level of the asperities

  there are overheating points favoring

in the tube.

  FIG. 3 is a sectional view similar to that of FIG. 2 but corresponding to another embodiment of tube 12. According to this embodiment, tube 12B contains an insert 18

  cruciform example, and which constitutes the favored means

  burning. This insert 18 may be coated, as indicated in dotted lines, on its surface

outside by catalyst 19.

  As before, at the catalyst level,

  where the combustion reaction is favored, the tempera-

  is higher than in the other parts

of the tube 12B.

  - Returning to Figure 1, we see that the sensor 14 is located upstream of the flame holder

  8 and is therefore protected by it against the

  flame. It is the same for the air intake 10 which supplies the tube 8 with combustion air supplied by

the fan 7.

  The combustion control device se-

  The invention can easily be mounted on

  existing stallations since it is sufficient to connect to the fuel supply (line 8) downstream of the stop valve 15 and to place the loop 12 in

the area of the burner flame.

Claims (3)

  1) Combustion control device   in a burner, a device comprising a reactor   cevant a fuel-dependent fuel mixture feeding the burner and a sensor for the combustion products of the reactor, characterized in that: - the reactor is constituted by a tube (8) connected to a fuel inlet (4) and an inlet of combustion air (10), - the tube (8, 12) is placed at least partly in the flame (13) of the burner, - the outlet of the tube (8) beyond the zone placed in the   the flame is provided with the sensor (14).   2 ') Device according to claim 1,   characterized in that the tube (8) forms at least one   loop (12) placed in the flame (13) of the burner.   ) Device according to any one of   Claims 1 and 2, characterized in that the tube   (8, 12) is made of a refractory material selected from the group consisting of steel with a high content of   nickel and chromium and a ceramic material.   4) Device according to claim 1, characterized in that the tube, at least in its part forming the reactor, has inside means   facilitating combustion (16, 17, 18, 19).    Device according to claim 4,   characterized in that the means facilitating the combustion   are catalysts (17, 19) in particular based on platinum, silver or palladium.   6 ') Device according to any one of these   Claims 1 to 5, characterized in that the part   inside the tube is provided with asperities (16) receiving   the catalyst (17) and forming overheating points fe.   7 ') Device according to claim 6,   characterized in that the asperities are constituted by inserts (18) placed inside the tube (12B), at least locally and forming a support for the catalyst (19).   8a) Device according to claim 6,   characterized in that the asperities (16) are constituted   killed by a tapping made inside the tube (12A).   90) Device according to any one of   Claims 1 to 8, characterized in that the entrance   fuel (11) and the air inlet (10) and   the sensor (14) are located on the tube (8) respectively.   upstream of the loop (12) placed in the flam- me (13).    ) Device according to claim 1, characterized in that the gas and oxidizer inlet means and the sensor are located in the vicinity of 1the flame holder (6) -.