EP4290163A1 - Drying plant - Google Patents

Abstract

The invention relates to a drying installation (1) for the continuous drying of moving belt material (2). The installation comprises: - radiant or heating elements (6), burning gas, - a gas flow circulation system (8) configured to suck up combustion products generated by the radiant or heating elements (6).The system gas flow circulation system (8) also comprises an extraction pipe (16) configured for the evacuation from the installation (1) of at least part of the combustion products sucked in by the flow circulation system gas (8).The installation (1) also comprises a device (18) for treating carbon monoxide and possibly nitrogen oxides, the treatment device (18) comprising an oxidation catalyst (20) and possibly reduction and being mounted on or downstream of said extraction pipe (16) in order to treat the carbon monoxide and possibly the nitrogen oxides contained in the combustion products. The installation (1) comprises in particular a means regulation (22) configured to regulate the temperature of the catalyst (20) to a temperature greater than or equal to 130°C.

Description

Technical area

The present invention relates to an installation for drying a moving strip material, in particular paper.

Prior art

Deposits on continuous web material require heat treatment. Heat treatment must often be carried out without contact in order to preserve the quality of the surface condition of the strip material or the deposit on it. This applies, for example, to paper webs which have undergone wet processing such as processing to produce art paper. Continuous heat treatment systems for strip material are known which combine infrared radiation and convection heating. There are systems comprising gas infrared emitters whose hot gas is drawn in by means of suction nozzles and discharged onto the belt by means of blowing nozzles, creating a combined radiation and convection heat treatment system.

The document US 6,088,930 discloses a convection and radiation system for the heat treatment of a strip which moves opposite gas infrared radiant elements and elements blowing hot air on this strip. The system comprises a succession of blowing elements separated from each other by at least one gas infrared radiating element. Each blower element includes on each side a suction element extending close to a gas infrared radiator.

The document WO 2005/085729 describes a system resulting in reduced mechanical energy consumption and reduced thermal energy loss, reduced capital and operating costs, and requiring less space. This drying installation is characterized by the fact that the suction devices, and possibly blowing devices, of the system mass transfer devices comprise at least one suction, and possibly blowing, device installed opposite the passband with respect to corresponding suction and blowing ducts which extend at least in the transverse direction of the band, and arranged to suck up and/or blow said combustion products so as to optimize the vector averages. The vectors represent the respective trajectories of the different jets of combustion products sucked in and/or blown out.

In this way, the heat transfers between the combustion products and the passage plane can be maximized, and it is also possible to obtain an extremely compact dryer installation into which the combustion products are blown at the highest possible temperature.

Presentation of the invention

The present invention aims to improve the operation of the installations described above. In particular, the present invention aims to provide an installation for drying a moving belt material, which is more environmentally friendly. More specifically, the present invention aims to provide an installation for drying a moving belt material, having a lower ecological impact.

• des éléments rayonnants ou chauffants, brûlant du gaz ou mélange gazeux, par exemple un pré-mélange de gaz et d'air,
• un système de circulation de flux gazeux, ou système de transfert de masse, par exemple à convection naturelle ou forcée, configuré pour aspirer des produits de combustion générés par les éléments rayonnants ou chauffants.

Thus, according to one aspect, a drying installation is proposed intended for the continuous drying of a material in a moving strip. The installation includes:

• radiant or heating elements, burning gas or gas mixture, for example a pre-mixture of gas and air,
• a gas flow circulation system, or mass transfer system, for example with natural or forced convection, configured to suck up combustion products generated by the radiating or heating elements.

The gas flow circulation system also includes an extraction pipe configured for the evacuation from the installation of at least a portion of the combustion products sucked in by the gas flow circulation system.

The installation also comprises a device for treating combustion products, the treatment device comprising an oxidation and/or reduction catalyst, and being mounted on or downstream of said extraction pipe in order to respectively treat the carbon monoxide. carbon and/or nitrogen oxides contained in the combustion products.

The catalyst may comprise, for example, a catalyst for oxidizing carbon monoxide to carbon dioxide and/or a catalyst for reducing nitrogen oxides NOx to dinitrogen N2.

The treatment device makes it possible to treat the gases released by the installation, so as to limit the quantity of carbon monoxide and/or nitrogen oxides present there.

The installation notably comprises a regulation means configured to regulate the temperature of the catalyst at a temperature greater than or equal to 130°C, preferably greater than or equal to 150°C, and more preferably greater than or equal to 200°C, or even 300 °C or 400°C.

Thus, the installation is configured to operate the treatment device in its optimal temperature conditions. More specifically, the installation is configured to operate the treatment device at a temperature allowing high efficiency to be obtained, throughout the operation of the installation.

Preferably, the regulating means is configured to heat the catalyst to a temperature greater than or equal to 130°C, preferably greater than or equal to 150°C, and more preferably greater than or equal to 200°C, or even 300°C or 400 °C, and/or the regulating means is configured to maintain the catalyst at a temperature greater than or equal to 130°C, preferably greater than or equal to 150°C, and more preferably greater than or equal to 200°C, or even 300 °C or 400°C.

More precisely, the installation is configured to operate the catalyst in its optimal temperature conditions, so as to obtain high efficiency of the oxidation and/or reduction reaction, throughout of the operation of the installation. Heating the catalyst to very high temperatures, in particular 300°C or 400°C, can also make it possible to obtain, at the outlet of the treatment device, the same efficiency but with fewer precious metals in the catalyst than for a device processing operating at a lower temperature.

Preferably, the regulation means comprises a heating element, such as an electrical element and/or a heat exchanger and/or an inductive means, configured to supply heat to the catalyst.

The electric or inductive heating means, for example a heating resistor or a coil, makes it possible to obtain a rapid and controlled rise in the temperature of the catalyst. Such an electric or inductive heating means is particularly suitable during periods of transient operation of the installation, for example at start-up, during which the combustion products to be treated may have a temperature lower than that desired for the operation of the treatment device. In particular, the inductive heating means is particularly advantageous for concentrating, by choice of material and/or geometry, the transfer of energy to locations in the catalyst where the thermal energy will be most useful. Likewise, the heat exchanger can be used to reuse calories available elsewhere, in particular in the installation, to increase the temperature of the catalyst, while limiting the energy consumption, in particular electricity, of the installation.

Preferably, the regulation means comprises control means configured to control the radiating or heating elements, and/or the gas flow circulation system and/or the treatment device, in order to regulate the temperature of the catalyst.

The control means can in particular be configured to control valves, valves, etc., in particular in the gas flow circulation system, or even the power supply, power, distribution, etc., of the radiating or heating elements.

Preferably, the regulation means comprises at least one carbon monoxide and/or nitrogen oxides sensor mounted upstream or downstream of the catalyst and configured to respectively measure the quantity of carbon monoxide and/or nitrogen oxides. nitrogen contained in the combustion products upstream and/or downstream of the catalyst. For example, the regulation means may comprise a carbon monoxide sensor, and possibly nitrogen oxides, mounted upstream of the catalyst, and a carbon monoxide sensor, and possibly nitrogen oxides, mounted in downstream of the catalyst.

Carbon monoxide and nitrogen oxide sensors make it possible to determine the quantities of carbon monoxide and nitrogen oxides present in the combustion products to be treated and supplying the treatment device. Such sensors also make it possible to determine the effectiveness of the treatment device on the oxidation of carbon monoxide or the reduction of nitrogen oxides. For example, such sensors can make it possible to identify normal or abnormal wear of the processing device, or an anomaly or even a drift in the operation of the processing device.

Preferably, the regulation means is configured to trigger an alert when the quantity of carbon monoxide and/or nitrogen oxides contained in the combustion products downstream of the catalyst is greater than a defined threshold.

Preferably, the regulation means is configured to maintain the catalyst at a temperature greater than or equal to 130°C, preferably greater than or equal to 150°C, and more preferably greater than or equal to 200°C, or even 300°C or 400 °C, when the quantity of carbon monoxide and/or nitrogen oxides contained in the combustion products upstream of the catalyst is greater than a defined threshold.

In particular, if the quantity of carbon monoxide and/or nitrogen oxides present in the combustion products to be treated is relatively low, in particular compared to one or more defined thresholds, the treatment device can be configured not to not regulate the temperature of the catalyst, in particular in order to avoid any unnecessary energy expenditure.

Preferably, the installation includes means for adding fresh air, for example in the gas or gas mixture supplying the radiating or heating elements and/or in the combustion products.

Preferably, the installation also includes means for adding fresh air, configured in particular to modify the quantity of fresh air present in the combustion products, and control means configured to control said means for adding air costs.

The addition of fresh air can be carried out upstream of combustion, for example in the gas or gas mixture supplying the radiating or heating elements, or downstream of combustion, for example in the combustion products formed by the radiant or heating elements. Thus, the means of adding fresh air can be a controlled valve modifying the composition of the gas, or gas mixture, supplying the radiating or heating elements, or else comprise a valve mounted on the extraction pipe and/or an inlet of cooling air in the installation.

The means for adding fresh air can be controlled by the control means as a function of the temperature of the combustion products, and/or as a function of the composition of the combustion products.

For example, the installation may include means for adding fresh air to the gas, or gas mixture, supplying the radiating or heating elements, and control means controlling the quantity of fresh air added to the gas supplying the elements. radiant or heating depending on the temperature or the composition of the combustion products entering the oxidation and possibly reduction catalyst.

Preferably, the installation also includes means for adding fresh air to the gas supplying the radiating or heating elements, and control means configured to reduce the quantity of fresh air added to the gas supplying the radiating or heating elements, when the quantity of carbon monoxide contained in the combustion products upstream of the catalyst is less than a defined threshold.

The quantity of air in the gases supplying the radiating or heating elements is generally greater than that required by the stoichiometry of the combustion reaction, in order to ensure complete combustion. However, if the quantity of carbon monoxide is low in the combustion products, this indicates that complete combustion has indeed taken place: it is then possible to reduce the quantity of fresh air supplying the radiating or heating elements, provided that the amount of carbon monoxide in combustion products remains low.

Preferably, the regulation means comprises said control means. Alternatively, the control means may comprise manual control means.

Preferably, the regulation means is configured to regulate the temperature and/or the composition of the combustion products entering the catalyst. For example, the regulation means can be configured to heat the combustion products, in particular without modifying their composition. In other words, the combustion products are heated by the regulating means while keeping the same composition.

The installation can also control the temperature of the catalyst via the combustion products to be treated, by controlling the temperature thereof. Such regulation is particularly advantageous during continuous operation of the installation, when the temperature of the combustion products to be treated remains substantially constant over time and can therefore be modified to the desired regulation temperature for the treatment device. By regulating the temperature of the combustion products supplying the treatment device to the desired temperature for the operation of the catalyst, it then becomes possible to obtain the desired operation for the latter, with a substantially similar temperature.

Preferably, the installation also includes means for determining the temperature of the catalyst, for example a temperature sensor mounted upstream of the catalyst, for example in the pipe extraction. The regulating means may comprise said means for determining the temperature of the catalyst.

Preferably, the installation also includes means for adding fresh air to the combustion products and/or to the gas supplying the radiating or heating elements, a temperature sensor mounted in the extraction pipe, upstream of the catalyst , and control means controlling the quantity of fresh air added to the combustion products and/or to the gas supplying the radiating or heating elements.

In order to control the temperature of the combustion products supplying the catalyst, the installation may include a temperature sensor mounted upstream of the catalyst, and means for adding fresh air to the installation, in order to reduce the temperature of the gases. feeding the catalyst. The addition of fresh air can thus be made to the combustion products supplying the catalyst, or to the gases supplying the radiating or heating elements.

Preferably, the means for adding fresh air comprise a controlled valve mounted on the extraction pipe, and configured to adjust the quantity of fresh air mixed with the combustion products.

The valve control allows you to adjust the quantity of fresh air added to the combustion products, to modify their temperature. The temperature of the combustion products is then adjusted just before they enter the catalyst.

Preferably, the means for adding fresh air comprise a cooling air inlet into the installation, preferably near the radiating or heating elements.

Another possibility of modifying the fresh air content of the combustion products, and therefore the temperature of the combustion products, is the modification of the cooling air used in the installation, in particular near the radiating or heating elements. This amount of cooling air can also be adjusted to obtain the desired temperature for the combustion products entering the catalyst.

Preferably, the regulation means comprises said control means. Alternatively, the control means may comprise manual control means.

Preferably, the catalyst comprises a metallic or ceramic honeycomb support, with at least one portion coated with one or more precious metals and/or with a means of injecting a reducing agent, for example ammonia.

Such supports, well known to those skilled in the art, make it possible to obtain very high active surfaces for a defined volume, which makes it possible to obtain higher yields.

Preferably, the installation also includes a catalyst unclogging device.

The unclogging device is intended to eliminate possible accumulations of residues within the catalyst and likely to block certain circulation channels of the gas to be treated. In order to maintain the effectiveness of the catalyst, the unclogging device can be used at regular intervals or when the pressure loss across the catalyst exceeds a defined threshold, in order to regain its nominal performance.

Preferably, the catalyst unclogging device is a device for circulating a fluid under pressure, for example compressed air, through the catalyst.

In order to unclog the catalyst, it is possible to use compressed air. In particular, the sudden injection of compressed air into the inlet gases makes it possible to create a sudden overpressure at the inlet of the catalyst which can break the accumulations of residues and can evacuate them with the rest of the treated gases. We then find a catalyst with the desired operation.

Brief description of the drawings

[ Fig. 1 ] There figure 1 represents a schematic view of a drying installation with a treatment device, according to the invention.

Description of embodiments

There figure 1 schematically illustrates an example of a drying installation 1 for the continuous drying of a material in a moving belt 2 according to the invention. The strip material 2 moves in the direction indicated by the arrow 4 through the drying installation 1.

The example of drying installation 1 preferably comprises several gas radiation emitters 6, supplied with gas such as a pre-mixture of gas and air, installed along the line of movement of the material in band 2, and a gas flow circulation system, or mass transfer system, 8 mounted downstream, in the direction of movement of the material in band 2, of the emitters 6 and configured to allow the circulation of a gas flow, for example by natural or forced convection.

Conventionally, the gas flow circulation system 8 comprises suction nozzles 10 and an extraction conduit 12 for sucking hot air, or combustion products, at the level of the moving strip material 2. The conduit d The extraction 12 is provided for the evacuation from the drying installation 1 of the combustion products sucked in via a central fan 14 of the drying installation 1 and one, or more, extraction pipes 16. The products combustion can thus be released outside, into the atmosphere, for example through a chimney, but can also, at least in part, be reused in another system. Thus, the combustion products leaving the treatment device as described below can be redirected into the drying installation itself, for example to a heat exchanger, or to another installation, for example a dryer. air.

The gas flow circulation system 8 may also include suction nozzles for suction of hot gases from the moving strip material to a suction conduit. The gas flow circulation system 8 may also comprise blowing nozzles for blowing, for example, at least part of the hot gas sucked into a blowing conduit towards the moving strip material, the blowing conduit being in fluid communication with the conduit suction, in particular via a fan. Such suction nozzles, and possibly blowing nozzles, in combination with the corresponding ducts, make it possible to recirculate the hot air present on the surface of the material in movable strip 2 during drying, so as to increase the proportion of vapor d water in the air before its evacuation from installation 1.

In order to limit the impact of the gases rejected by the installation 1, the latter also includes a device for treating the combustion products 18 mounted on the extraction pipe 16, for example downstream of the central fan 14. The device treatment 18 aims to limit in particular the content of carbon monoxide and possibly nitrogen oxides present in the combustion products rejected by the installation 1, before their release into the open air.

For this purpose, the treatment device 18 may comprise an oxidation and possibly reduction catalyst 20, mounted on the extraction pipe 16 and making it possible to react the carbon monoxide with an oxidizing compound, for example carbon dioxide oxygen. air, to transform it into carbon dioxide, and possibly to react the nitrogen oxides with a reducing compound, for example ammonia or urea injected into the catalyst 20. The catalyst 20 can thus be arranged, in a conventional manner, on a support having a high active, or contact, surface. The catalyst 20, present on the surface of the support, allows the implementation of the reaction of oxidation of carbon monoxide to carbon dioxide and/or reduction of nitrogen oxides to dinitrogen. The support may in particular be a metallic or ceramic support, and have a honeycomb geometry. The catalyst may for its part comprise an oxidation catalyst with precious metals and/or a reduction catalyst associated with a means of injecting a reducing agent such as ammonia or urea. For example, the catalyst 20 may comprise a first portion with a reduction catalyst, associated with means for injecting a reducing agent, and a second portion with an oxidation catalyst. Preferably, the catalyst comprises a reduction catalyst, part of which is coated with precious metals to oxidize the carbon monoxide.

However, in order to allow high efficiency of the catalyst 20 during the different operating phases of the drying installation 1, the device treatment 18 also comprises means 22 for regulating the temperature of the catalyst 20. The regulation means 22 is configured to allow the catalyst 20 to be in its nominal operating temperature range, for example at a temperature greater than or equal to 130°C, preferably greater than or equal to 150°C, and more preferably greater than or equal to 200°C. Alternatively, or in addition, the regulation means 22 can be configured to allow the catalyst 20 to be at a temperature greater than or equal to 300°C, or even 400°C, so as to increase its efficiency or so as to obtain similar efficiency with a catalyst less rich in precious metal but operating at a lower temperature.

For this purpose, the regulation means 22 can be configured to allow a rapid modification of the temperature of the catalyst 20 when this is outside said nominal temperature range, and/or to allow the temperature to be maintained. of the catalyst 20 when this is within said nominal temperature range.

For example, the regulating means 22 can be configured to heat the catalyst 20 to a temperature greater than or equal to 130°C, preferably greater than or equal to 150°C, and more preferably greater than or equal to 200°C or even 300° C or 400°C, and/or to maintain the oxidation catalyst at a temperature greater than or equal to 130°C, preferably greater than or equal to 150°C, and more preferably greater than or equal to 200°C, or even 300 °C or 400°C.

Thus, the regulating means 22 may comprise a heating element 24, such as an electrical element and/or a heat exchanger, for example mounted in or in contact with the support of the catalyst 20, in order to heat the latter when its temperature is too low, particularly during the start-up phases of the installation 1. The heating element 24 is thus used temporarily, in order to put the catalyst in its nominal operating conditions until it can remain there independently . Furthermore, the heat exchanger can be advantageously used to recover the calories released elsewhere in the installation and to supply them to the catalyst in order to heat it without increasing the energy consumption of the installation.

The regulation means 22 can also regulate the temperature of the combustion products supplying the catalyst 20, so that they have a temperature included in the nominal temperature range of the catalyst 20, so as to place or maintain the catalyst 20 in its range of nominal temperatures.

In order to modify the temperature of the combustion products conveyed by the extraction pipe 16 and supplying the catalyst 20, the regulation means 22 can comprise a control means 26 configured to add fresh air to the combustion products, i.e. before the combustion of the gas by the emitters 6, either between combustion and suction by the gas flow circulation system 8, or after suction by the gas flow circulation system 8.

Thus, the control means 26 can increase or decrease the quantity of fresh air mixed with the gas supplying the emitters 6, before their combustion, so as to obtain less or hotter combustion products. Likewise, when the quantity of carbon monoxide in the combustion products supplying the treatment device 18 is less than a defined threshold, the control means 26 can also reduce the quantity of fresh air supplying the emitters 6, since combustion is already being carried out completely.

Alternatively, or in addition, the control means 26 can increase or decrease the quantity of fresh cooling air introduced into the installation 1 between the gas emitters 6 and the gas flow circulation system 8. Such cooling air , by mixing with the combustion products before suction by the gas flow circulation system 8, makes it possible to obtain a modification of the temperature of the gases conveyed by the extraction pipe 16 to the catalyst 20.

Finally, alternatively or in addition to the embodiments described above, the control means 26 can also be configured to add or not fresh air in the combustion products, at the level of the extraction pipe 16 supplying the catalyst 20. For example, the treatment device 18 may include a controlled valve 28 for adding fresh air which is mounted on the extraction pipe 16, upstream of the catalyst 20. The controlled valve 28 is connected to a fresh air inlet and allows, depending on the command given by the control means 26, to add or not, or else to modify a quantity of fresh air added to the combustion products, so as to change their temperature.

In order to determine the control of the controlled valve, or of the fresh air supplies of the emitters 6 or of the cooling means of the installation 1, the treatment device 18 may comprise one or more temperature sensors, one or more monoxide sensors carbon and/or one or more nitrogen oxide sensors (not shown), mounted at different points of the installation 1, for example upstream, on or downstream of the catalyst 20 but also at the level of the pipe extraction 16. The control means 26 can then determine a command from the information provided by this or these sensors.

The control means 26 can also directly control the power of the radiating or heating elements 2, for example individually or globally. Thus, the control means 26 can regulate the temperature of the catalyst by modifying the power or the number of the radiating or heating elements 6 operating in the installation 1, or the distribution of the radiating or heating elements 6 operating in the installation 1. Likewise, the frequency or the circulation paths of the gas flows in the circulation system 8 can be modified by the control means in order to obtain the desired temperature for the combustion products entering the catalyst 20.

Finally, and in order to limit the phenomena of clogging of the catalyst 20, in particular of the channels of the support, the treatment device 18 can comprise a unclogging device 30. The unclogging device 30 can for example be a device for circulating a fluid under pressure, for example compressed air, through the catalyst and be mounted upstream or downstream of the catalyst 20. By creating a significant pressure difference between the inlet and outlet of the catalyst 20, the unclogging device 30 can then reduce or break the blockages likely to have formed in the channels of the support, and evacuate them outside the catalyst 20.

The use of the unclogging device 30 can in particular be controlled as a function of the operating time of the catalyst 20, for example with an unclogging procedure planned every 20, 30 or 50 hours of operation of the catalyst 20. Alternatively, the unclogging device unclogging 30 can be controlled as a function of the evolution of the pressure loss between the inlet and the outlet of the catalyst 20, for example when such a pressure loss exceeds a defined threshold or increases, for a defined time, d 'a defined value.

Thus, thanks to the invention, it becomes possible to treat efficiently and in the long term, combustion products rejected by an installation for drying a material in a moving belt. In particular, the processing device is configured to operate as long as possible in its nominal zone, including during transient periods, in particular start-up. Likewise, prolonged operation is ensured thanks to the unclogging device which keeps the catalyst capable of treating the combustion products conveyed through the extraction pipe.

Claims (13)

Drying installation (1) intended for the continuous drying of a moving belt material (2), the installation (1) comprising: - radiant or heating elements (6), burning gas, - a gas flow circulation system (8) configured to suck up combustion products generated by the radiating or heating elements (6), in which the gas flow circulation system (8) also comprises an extraction pipe (16) configured for evacuating from the installation, at least part of the combustion products sucked in by the gas circulation system gas flow (8), characterized in that the installation (1) also comprises a device (18) for treating combustion products, in particular carbon monoxide and possibly nitrogen oxides, the treatment device (18) comprising an oxidation and possibly reduction catalyst (20), in particular for oxidizing carbon monoxide and possibly reducing nitrogen oxides, and being mounted on or downstream of said extraction pipe (16) in order to treat the carbon monoxide and possibly nitrogen oxides contained in the combustion products, and in that the installation (1) also comprises a regulation means (22) configured to regulate the temperature of the catalyst at a temperature greater than or equal to 130°C, preferably greater than or equal to 150°C, and more preferably greater than or equal to 200°C, or even 300°C or 400°C. Installation (1) according to claim 1, in which the regulating means (22) is configured to heat the oxidation and possibly reduction catalyst (20) to a temperature greater than or equal to 130°C, preferably greater than or equal to at 150°C, and more preferably greater than or equal to 200°C or even 300°C or 400°C, and/or in which the regulating means (22) is configured to maintain the oxidation and possibly reduction catalyst (20) at a temperature greater than or equal to 130°C, preferably greater than or equal to 150°C, and more preferably greater than or equal to 200°C, or even 300°C or 400 °C. Installation (1) according to claim 1 or 2, in which the regulating means (22) comprises a heating element (24), such as an electrical element and/or a heat exchanger, configured to supply heat to the oxidation catalyst and possibly reduction (20). Installation (1) according to any one of the preceding claims, in which the regulating means (22) comprises at least one carbon monoxide sensor, and possibly nitrogen oxides, mounted upstream and/or downstream of the catalyst (20) and configured to measure the quantity of carbon monoxide and possibly nitrogen oxides contained in the combustion products upstream and/or downstream of the catalyst (20), for example a carbon monoxide sensor, and possibly nitrogen oxides, mounted upstream of the catalyst (20) and a carbon monoxide sensor, and possibly nitrogen oxides, mounted downstream of the catalyst (20). Installation (1) according to the preceding claim, in which the regulating means (22) is configured to maintain the catalyst (20) at a temperature greater than or equal to 130°C, preferably greater than or equal to 150°C, and more preferably greater than or equal to 200°C, or even 300°C or 400°C, when the quantity of carbon monoxide, and possibly nitrogen oxides, contained in the combustion products upstream of the catalyst (20), is greater than a defined threshold. Installation (1) according to claim 4 or 5, in which the installation (1) also comprises means for adding fresh air to the gas supplying the radiating or heating elements (6), and in which the regulating means (22) comprises control means (26) configured to reduce the quantity of fresh air added to the gas supplying the radiating or heating elements (6) when the quantity of carbon monoxide contained in the combustion products upstream of the catalyst ( 20), is less than a defined threshold. Installation (1) according to any one of the preceding claims, in which the regulation means (22) is configured to regulate the temperature of the combustion products entering the oxidation and possibly reduction catalyst (20). Installation (1) according to the preceding claim, in which the installation (1) also comprises means for adding fresh air to the combustion products and/or to the gas supplying the radiating or heating elements (6), and in which the regulation means (22) comprises a temperature sensor mounted in the extraction pipe (16), upstream of the oxidation and possibly reduction catalyst (20), and control means (26) controlling the quantity of fresh air added to the combustion products and/or to the gas supplying the radiant or heating elements (6). Installation (1) according to the preceding claim, in which the means for adding fresh air comprise a controlled valve (28) mounted on the extraction pipe (16), and configured to adjust the quantity of fresh air mixed with the combustion products. Installation (1) according to claim 8 or 9, in which the means for adding fresh air comprise an air inlet of cooling in the installation, preferably near the radiating or heating elements (6). Installation (1) according to any one of the preceding claims, in which the oxidation and possibly reduction catalyst (20) comprises a metallic or ceramic honeycomb support, with at least one portion coated with one or more metals precious and possibly with a means of injecting a reducing agent, for example ammonia. Installation (1) according to any one of the preceding claims, also comprising a device (30) for unclogging the oxidation and possibly reduction catalyst (20). Installation (1) according to the preceding claim, in which the device (30) for unclogging the oxidation and possibly reduction catalyst (20) is a device for circulating a fluid under pressure, for example compressed air, through the oxidation and possibly reduction catalyst (20).

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