FR2497560A1 - Neutralisation plant for toxic or waste gases - which are mixed with air of combustion and then with fuel gas and fed to burner producing very hot micro:flames - Google Patents

Abstract

The plant is autonomous, and can be located inside or outside a building. The toxic and/or waste gases are mixed with air of combustion to form a mixt. (a) fed through a filter, fan and valve to a mixing point. A fuel gas (b) is fed through a pressure redn. valve and safety valve to the mixing point to produce a gas mixt. (a,b). Mixt. (a,b) is fed to a burner in which the waste or toxic gases are neutralised by combustion. The burner pref. contains several nozzles forming micro-flames with flame tips at ca. 1400 deg.C. Flammable waste gases can be added to the air of combustion; and complete combustion of the mixt. (a,b) is ensured despite variation in the amt. of toxic or waste gas added to the air of combustion.

Description

 The present invention relates to a gaseous effluent neutralizer and a method for their elimination.

 According to the prior art, apparatuses known as effluent or smoke burners are known in which the gases pass into an expansion chamber through the flame of a burner.

 In accordance with this known technique, the effluents are conveyed directly to the burners and such an arrangement has many disadvantages because, due to the nature of the effluents, the quality of combustion is poor and, as a result, it results Numerous uncertainties remain as to the disposal of said effluents.

 The present invention remedies the aforementioned drawbacks and proposes both an apparatus and a method which eliminate the uncertainties according to the prior art.

 The present invention relates more particularly to an anti-pollution apparatus which is designed in such a way that the effluents which serve as a combustible mixture and which are added to the combustion gas in any suitable proportion pass through microburners whose darts are located at a temperature ensuring the combustion or complete neutralization of said effluents.

 The apparatus and method according to the present invention make it possible to neutralize flammable gaseous effluents and said effluents play the role of combustion air.

 In accordance with the present invention, the gaseous effluent neutralizer constituted by an autonomous device capable of being placed both inside and outside of a building comprises, partly upstream, at least two intake pipes , one intended for the transport of effluents and the other for the transport of a combustion gas, the effluents introduced into the first pipe being contained in combustion air and passing through a treatment and regulation assembly to be mixed at a suitable junction point with the combustion gas, the supply of which is also regulated by another control assembly, said mixture then being directed, partly downstream, into a burner where the effluents are neutralized by combustion.

The following characteristics, taken individually or in combination, relate to the present invention
- the treatment and regulation assembly of the effluent-oxidant air mixture includes a filter to eliminate unwanted impurities, a fan to accelerate the circulation of said mixture, an adjustment valve to ensure the passage of the appropriate flow rate of said mixture as well as a pressure gauge for checking the necessary pressure
- the control assembly for the combustion gas supply consists of a stop valve to stop the gas supply when necessary, a pressure gauge and a safety solenoid valve for mixing programmed gas at the junction of the two intake pipes
- the neutralizer comprises downstream of the junction point where the effluents contained in the combustion air and the combustion gas are produced, an air supply device at constant pressure
- the effluents are burned in a burner whose darts of the micro-flames are at around 14000C
- the air and gas pressures are identical and are included in the range - from 20 to 60 mbar
- the gas used for the combustion of the effluents is chosen from natural gas, butane, propane and the like
the process for the elimination of effluents consists in first mixing the effluents with air and treating them so that they serve as oxidizer and in adding them in a suitable proportion to gas to obtain an air- gas-effluent which is conveyed in a burner for the combustion of said mixture, said effluents being thus completely eliminated by combustion.

 Various advantages and characteristics of the present invention will emerge from the detailed description below.

The invention is shown, by way of non-limiting example, with reference to the accompanying drawings in which
Figure 1 is a block diagram of the gaseous effluent neutralizer according to the present invention
Figure 2 is a detail view of the burner taken according to part A of Figure 1.

 In the accompanying drawings, the neutralizer for gaseous effluents in the form of a self-contained device capable of being placed both inside and outside of a building is designated as a whole by 1.

 The neutralizer 1 comprises, partly upstream, a first intake pipe 2 for the transportation of the effluents contained in the combustion air. These effluents or toxic gases X are always contained in a certain volume of air which varies according to the case, is in suitable proportion and also variable which must not give rise, in the extreme case to their condensation which depends on their dew point. The amount of air in the mixture (air-effluents) introduced into line 2 is, in general, always greater than the theoretical amount of air to burn the effluents, the excess air being used to supplement the air required to supply the burner. The effluent air mixture introduced via line 2 passes through a treatment and regulation assembly constituted by a filter 3 in which unwanted impurities are eliminated. This mixture is conveyed by a fan 4 and an adjustment valve 5 as well as a pressure gauge 6 are used to control the parameters necessary before mixing with the gas at junction point 7.

 The combustion gas, which is a conventional gas and which is chosen from natural gas, butane, propane and the like, is conveyed via another intake pipe 8 provided with a control assembly constituted by a stop valve 9, a pressure reducer 10 and a safety solenoid valve 11.

 The mixture between the effluents contained in the combustion air and the combustion gas takes place at junction 7. The air pressures t of gas are identical and the air / gas pressure can vary within a range between 20 and 60 mbar.

 provides downstream of the junction point 7, a constant pressure air supply device 12 to allow, if necessary, an external supply in the event of an air fault. The air-gas-effluent mixture is then introduced into the burner 13 to undergo combustion.

 As shown in Figure 2 the burner 13 is of the type comprising a multitude of micro flames 14 whose darts are at a temperature of about 14000C; in this figure, the supply of the mixture. air-gas-effluent has been designated by the reference symbol 15.

 The burner 13 is supplied with an excess of air of the order of 10 to 20%. The quantity of air necessary to burn the effluents and the gas at a certain temperature corresponds on the one hand to the theoretical quantity of air necessary to burn the effluents and the surplus to burn the gas and, as we have indicated above, in the event of an air fault, there can, of course, be an external report.

The operation of the neu trallsateur 1 of the present invention is indicated below.
the fan 4 is started, the effluents contained in combustion air, the routing of which can be captured from a hood (not shown) enter the pipe 2, pass through the filter 3 before entering the fan 4. The presence of combustion air at the supply air is noted in the burner 13 using the device 12. When the contact of this device 12 is closed, the flame control card for the burner is supplied 13 which, for 5 seconds, causes a spark upon ignition by means of an electrode and an opening of the solenoid valve li, the 1: 3 burner being lit, the flame is checked using a thermocouple (not shown).

gas
In the event of a flame fault, the supply solenoid valve / 11 is closed as well as the combustion air fan 4 is stopped (locked out). It is then necessary to carry out a manual intervention (reset) to reset the neutralizer 1.

Thus, in accordance with the present invention, it is possible to obtain the total combustion of the effluents in a reduced enclosure thanks precisely to the multitude of mi
cro flames 14.

It is important to note that the nature of the effluents can be very variable and that they are combustible effluents that have not received any transformation other than that resulting
both of the normal combustion of gases.

The invention is not limited to the embodiments
tion represented and described in detail because various modifications
tions can be made without departing from its scope.

Claims (8)

 1. Neutralizer for gaseous effluents constituted by an autonomous device capable of being placed both inside and outside a building, characterized in that it comprises, partly upstream, at least two intake pipes (2,8), one (2) intended for the transport of effluents and the other (8) for the transport of a combustion gas; the effluents introduced into the first pipe (2) being contained in the combustion air passing through a treatment and regulation assembly 13,4,5,6) to be mixed at an appropriate junction point (73 with the combustion gas, the supply of which is also regulated by another control assembly ( 9, 10, 11), said mixture then being directed, partly downstream, into a burner (13) where the effluents are neutralized by combustion.  2. Neutralizer for gaseous effluents according to claim 1, characterized in that the treatment and regulation assembly (3,4,5,6) of the effluent-oxidant air mixture comprises a filter (3) for eliminating the undesirable impurities, a fan (4) to accelerate the circulation of said mixture, an adjustment valve (5) to ensure the passage of the appropriate flow of said mixture as well as a pressure gauge (6) for controlling the necessary pressure.  3. Neutralizer for gaseous effluents according to one of claims 1 or 2, characterized in that the control assembly (9,10,11) for supplying the combustion gas consists of a shut-off valve (9i to stop the gas supply when necessary, a pressure gauge (10) and a safety solenoid valve (11) for the programmed mixture of gas at the junction point (7) of the two intake pipes ( 2.8).  4. Neutralizer for gaseous effluents according to any one of claims 1 to 3, characterized in that it comprises downstream of the junction point (7) or occurs the mixing of the effluents contained in the combustion air and combustion gas a constant pressure air supply device (12).  5. Neutralizer for gaseous effluents according to any one of claims 1 to 4, characterized in that the effluents are burned in a burner (13) whose darts of micro flames (14) are at around 14000C,  6. Neutralizer of gaseous effluents according to any one of claims 1 to 5, characterized in that the air and gas pressures are identical and included in the range of 20 to 60 mbar.  7. Neutralizer for gaseous effluents according to any one of claims 1 to 6, characterized in that the gas used for the combustion of the effluents is chosen from natural gas, butane, propane and the like.  8. Process for the elimination of gaseous effluents, characterized in that it consists in first of all mixing the effluents with air and in treating them so that they serve as oxidizer and in adding them in suitable proportion to gas to obtain an air-gas-effluent mixture (15) which is conveyed in a burner (13) for the combustion of said mixture, said effluents being thus completely eliminated by combustion.