WO2010086085A2 - Method for operating an oxidation system and oxidation system - Google Patents

Abstract

The invention relates to a method for operating an oxidation system (1) having a prescribed average heat input by means of a reaction material present at a changing concentration, wherein a desired heat profile is maintained in at least one heat bed (3,4,5) of a heat exchanger (2) by the heat input. A heat store (11) for receiving excess heat and/or dissipating heat, in particular in the case of a lower than average heat input, is in particular directly coupled to a combustion chamber (6) of the oxidation system (1) for charging. The invention further relates to an oxidation system (1).

Description

 Method for operating an oxidation plant and Oxidationsanlaqe

description

The invention relates to a method for operating an oxidation Anläge, with a planned average heat input by means of a present in varying concentrations of reactant, wherein the heat input a desired heat profile in at least one heat bed of a heat exchanger is maintained. The invention further relates to an oxidation plant.

Method of the type mentioned are known. Such a method can be used, for example, for operating a thermal-regenerative exhaust air purification system that represents the oxidation system. In this application, it serves to remove hydrocarbons, ie reactants, from exhaust air of a preceding process by oxidation, in particular total oxidation. By the oxidation of the exhaust gas resulting exhaust gases can subsequently the cleaning system as pure gas, ie without reactants, are discharged into the environment. The raw gas supplied to the exhaust-air purification plant, that is to say air contaminated with the hydrocarbons, can have a time-varying concentration of the hydrocarbons. This means that the exhaust air supplied to the exhaust air purification system may contain different proportions of the reactant at different times. Since the oxidation of the hydrocarbons only occurs at a certain reaction temperature in the exhaust air purification system, this temperature must be generated and maintained in the system. Advantageously, in the oxidation of the hydrocarbons, a heat input into the system, due to which the necessary temperature is present in the system. However, this is only possible from a con- concentration, which is greater than a design concentration, the case. Below the design concentration of the exhaust gas purification plant additional fuel must be supplied to reliably and completely oxidize the pollutants contained in the exhaust air, ie hydrocarbons, or burn.

To increase the efficiency of the exhaust air purification system, the heat exchanger is provided. This results in the combustion of the hydrocarbons resulting heat of the exhaust air, so that it already has a temperature when entering a reaction or combustion chamber of the exhaust air purification system, which is higher than the outlet temperature of the exhaust air. In particular, the heat exchanger has a plurality of heat beds, which can be operated alternately in different operating modes, namely raw gas operation, clean gas operation and rinsing operation. In raw gas operation, the polluted exhaust air is passed through the heat bed, the heated bed was previously heated by passing, hot clean gas. In the clean gas mode, the hot, coming from the combustion chamber clean gas is passed through the appropriate heat bed, so that it is heated, then to make the crude gas operation, the oxidation of the hydrocarbons or the reactant can. In the rinsing mode, a warming bed is operated to ensure that no raw gas escapes into the environment when a bed of heat passes from the raw gas mode to the clean gas mode, ie it must be ensured that no raw gas is left in the bed. For this purpose, pure gas originating from the combustion chamber of the exhaust air purification plant is passed through the heat bed to be rinsed and returned to the raw gas stream. In this way, with a sufficient dimensioning of the heat bed, an autothermal operation of the exhaust air purification system can be ensured. In the autothermal operation of the exhaust air purification system no additional fuel must be supplied to completely oxidize the hydrocarbons. For oxidation, therefore, only the heat generated during the oxidation is sufficient. In order to achieve oxidation even at low concentrations, ie concentrations below the average concentration of the reactant present, the heat bed must be dimensioned to a design concentration at which the autothermal operation is to be carried out. This means that the lower the expected average concentration of the reactant, the larger the heat-bed must be, in order to supply sufficient heat of the exhaust gas of the exhaust air or the reactant. However, the larger the size of the heat bed, the greater the temperature drop over it. The exhaust gas temperature drops from the high temperature to a low temperature via the heat bed.

However, this has the disadvantage that the discharged from the Abluftreinigungsanla- ge exhaust gases have too low a temperature in order to make good use of them for a process in another system can. Also, a so-called bypass must be provided in the exhaust air purification system, via which the exhaust gas - with the fully oxidized hydrocarbons - can be discharged directly from the combustion chamber of the exhaust air purification system into the open air. This is necessary in order to avoid overheating of the exhaust air purification system or of the heat bed at a high concentration of the reaction substance. So it is difficult to interpret the exhaust air purification system such that they works efficiently over a wide concentration range of the reactant. If the system is designed for a high concentration of the reactant, then additional fuel must be introduced when operating at low concentrations, while when designed for low concentrations in a high concentration operation, exhaust gas is discharged directly from the combustor to the heat contained therein can not be implemented in the heat exchanger and consequently lost.

It is therefore an object of the invention to propose a method for operating an oxidation system, which can be operated efficiently over a wide concentration range, so that as little additional fuel must be introduced and as little unused heat is released with the exhaust gas.

This is achieved according to the invention with a method for operating an oxidation system having the features of claim 1. In this case, a, in particular directly to a combustion chamber of the oxidation system coupled for charging, heat accumulator is provided which serves to absorb heat surplus and / or release of heat, in particular in the case of a below-average heat input. An oxidation system serves, for example, to purify a pollutant having raw gas, ie a gas which has the reactant, so that no negative influences of the reactant on an environment of the oxidation system occur. This is achieved by subjecting the crude gas to temperature so that the reactant reacts completely or oxidizes. The reactant may thus be a fuel. To increase the efficiency of the oxidation system of the heat exchanger is provided with which heat the exhaust gas of the oxidation plant is introduced into this supplied raw gas. In this case, a re-heating of 95% is possible, that is, 95% of the heat contained in the exhaust gas of the oxidation system can be returned to the raw gas. In order to avoid that a reaction of the reactant is feasible only with the introduction of additional fuel, the heat accumulator is provided. This serves to absorb heat surplus, ie heat that can not be converted in the heat exchanger. Excess heat is present, for example, if the concentration of the present reaction substance is above the design concentration of the oxidation plant.

If there is only a below-average heat input, ie if the concentration of the reactant has fallen below the design concentration of the system, heat can be released from the heat reservoir. In this case, a heat profile is to be maintained in particular in the heat bed, which allows a reaction of the reactant. In this way, the reaction of the reactant can be maintained without having to bring additional fuel into the system. For example, the method can be used to operate a thermally regenerative exhaust air purification system in which exhaust air charged with a time-varying amount of pollutants is passed through the heat exchanger for heating by the heat exchanger and then to the oxidation of the pollutants. Above and at the design concentration is a self-sustaining operation of the exhaust air purification system feasible.

The heat accumulator can be supplied with heat at a concentration that is greater than the design concentration, and at a smaller concentration heat for continuous self-sustained operation of the oxidation system are returned to the combustion chamber. In this case, the heat accumulator is arranged, for example, fluidically parallel to the heat exchanger. The described procedure can be used not only to operate the oxidation plant but also to design it. The design is thus provided so that the heat accumulator absorb heat surplus and / or heat, in particular in the case of below-average heat input, ben again ben. In this way, the oxidation plant can be designed so that an autothermal operation over a wide concentration range can be provided. Compared to an oxidation system known from the prior art, for example, the design concentration of the system can be selected to be higher. The method can also be applied to a generic thermal installation.

By means of the heat accumulator, a sufficiently large heat storage can be temporarily stored and, if necessary, ie with a time delay, released again. This heat supply can be used both for discharging the heat required for a reaction, as well as for ensuring a continuous operation of another system which is connected to the oxidation system. In this case, a continuous heat release of the heat accumulator can be provided, so not only in the presence of below-average heat input. This is especially true in the case of a stationary operation of the oxidation system in which the heat accumulator continuously supplied heat and withdrawn. The heat storage can be connected directly to the reaction chamber or the combustion chamber of the system. That means, that the exhaust gas of the system is tapped for the heat storage before it passes through the heat exchanger. For example, the heat exchanger is provided fluidically parallel to the heat storage. In this way, the heat storage fluid supplied to a high temperature level.

Additionally or alternatively, an adapted dimensioning of the heat bed can be provided. The heat bed is sized smaller than would be necessary for an autothermal reaction at a low concentration of the reactant. So there is a Unterdimensionierung of the heat bed, the design concentration of the system is thus selected higher. This means that in a conventional oxidation system, a reaction of the reactant would be possible only with the introduction of additional fuel, if the concentration temporarily falls below the design concentration of the plant. This is prevented by the provision of the heat accumulator. As described above, heat is released therefrom, especially if the below-average heat input is present. Thus, even at a concentration that is below the design concentration of the system, operation of the system can be ensured. Due to the at least partial separation of reaction kinetics, so the combustion chamber and the heat exchanger, from the heat storage in the heat storage, it is not only possible to react more flexible to changing concentrations of the reactant, but it is also a return of exhaust gas of the oxidation system with higher temperatures can be realized. This means that the exhaust gas of the oxidation system can be delivered to another system for the sensible use of heat. It is also advantageous that by means of the heat accumulator a sufficiently large heat stored and cached if necessary, ie delayed. By undersizing the heat bed, it is also possible to reduce the pressure loss via the heat bed.

A development of the invention provides that the system emits heat stored in the heat accumulator to at least one other system. In order to use the heat energy stored in the heat storage, this is delivered to another facility. Of particular importance in this case is the arrangement of the heat accumulator. While plants are known from the prior art, which provide heat storage in the other plant, the heat storage is included here in the oxidation system and arranged in this way between the combustion chamber and the other system. In this way, it is possible to increase the efficiency of the overall process, including both the oxidation plant and the at least one further plant. It can also be provided that the heat stored in the heat accumulator is released to the further system. This is also the case if the concentration of the reaction substance falls below the design concentration of the oxidation system, so that only a below-average heat input is present. In this case, the heat stored in the heat accumulator can ensure both the reaction of the reactant and the reliable and continuous operation of the further system. However, it can also be provided that the heat accumulator absorbs the heat surplus and delivers exclusively to the operation of the further system, while the reaction of the reactant is maintained, for example, with the introduction of additional fuel. A development of the invention provides that the temperature of a further system for the heat dissipation of supplied fluid is controlled and / or regulated. Before the heat energy generated in the oxidation system or stored in the heat storage is supplied to the fluid of the further system, the temperature present must be adapted. For example, adjusting the temperature to a design temperature of the other system. In particular, an over-temperature should be avoided, which can lead to damage to the other system. The adaptation takes place, for example, by mixing in cold fluid.

A development of the invention provides that a further heat exchanger, a heater, a production device, a refrigerating machine or an energy converter device is used as a further system. The further heat exchanger may be part of a secondary circuit, the heat of the exhaust gas of the oxidation plant is supplied. By means of the further heat exchanger, the heat is transferred to a fluid (for example thermal oil, steam or water) of the secondary circuit, in which a further transport of the heat takes place to a place of use. For example, the secondary circuit may cooperate with a heater or a production device. This is called indirect heat use. But the heating or the production device can also represent the other system and be directly charged with the heat (direct heat use). This can be provided, for example, for operating a hot-air dryer. Likewise, operating or heating the production device is possible. If the other system is a chiller, in particular an absorption chiller, then a this fluid flowing through be brought to a lower temperature. However, the heat energy can also be used when using an energy converter device as a further system for generating, for example, electrical or mechanical energy. For this purpose, for example, a gas or steam turbine or a fuel cell can be used. As already described, the peculiarity of the oxidation system is that the heat accumulator is provided between the combustion chamber and the further system, that is, not initially a heat exchange to a lower temperature is performed and only then the heat is stored.

A further development of the invention provides that a reaction of the reaction substance in the heat bed and / or the combustion chamber takes place, wherein by means of the heat exchanger the reactant supplied to the heat bed and / or the combustion chamber is heated with heat from exhaust gas flowing out of the combustion chamber. The reaction of the reactant proceeds as soon as it has reached a sufficiently high temperature. This may already be the case when passing through the heat bed, so that the reaction can already take place in the heat bed. Alternatively or additionally, the combustion chamber is provided for the reaction of the reactant. In the combustion chamber, for example, a burner is arranged, which generates a permanent flame. Thus, a support temperature is generated or the reactant warmed up by passing through the heat bed is ignited. The heat exchanger serves to extract heat from the exhaust gas flowing out of the combustion chamber and to supply it to the reactant or the exhaust air. In this case, the heating bed or the combustion chamber supplied reactant is heated, creating a Reaction of the reactant in the heat bed or the combustion chamber is made possible.

A development of the invention provides that at least a portion of the exhaust gas is used in addition to heating the heat accumulator. The resulting in the combustion chamber exhaust gas, in which the reactant is already completely oxidized, is used both for a heat exchange process between the exhaust gas and the non-oxidized or spent reactant as well as for heating the heat accumulator. The heating is carried out in particular when the concentration of the reaction substance exceeds the design concentration of the oxidation system and thus there is excess heat.

A development of the invention provides that the heat accumulator is heated to almost the highest temperature present in the oxidation system. In order to use the heat generated in the oxidation system as efficiently as possible, the present or the highest temperature present in the reaction of the reactant should also be available in the heat accumulator. This is therefore heated at least almost to this highest temperature. When unloading the heat accumulator for releasing heat to maintain the heat profile or to operate the other system is therefore essentially this high temperature available.

A further development of the invention provides that a long-term heat store is used as the heat store. This means that the heat storage can hold the stored heat for a longer period of time, for example up to several days. It is It is advantageous if a resulting during heating of the heat storage temperature stratification in the heat storage is maintained as long as possible, so no equalization of the temperature takes place in the heat storage. Usually, in a heat accumulator after completion of a loading process with time, in particular after a long standstill, a temperature which corresponds to a mean temperature of the heat accumulator. By means of the heat accumulator so only a temperature can be achieved when removing the heat, which corresponds to the average temperature. In contrast, it is desirable in the oxidation system to achieve as possible a temperature which corresponds to the high temperature present during loading. So there should be a temperature stratification in the heat storage, which is maintained even with a long service life. Thus, depending on the direction of flow of the heat accumulator, when removing the heat, a temperature which is below the mean temperature can be achieved. The desired temperature can therefore be selected with a suitable choice of the direction of flow. This is due to the described temperature stratification.

An advantageous embodiment of the invention provides that at a concentration which is below a minimum concentration, additional fuel is introduced into the combustion chamber and / or the heat bed. If the concentration of the reactant present is too low, ie if it is below the design concentration, the system can only be operated with the introduction of heat. This means that either heat must be released from the heat storage or additional fuel must be introduced into the system. If the minimum concentration, which is less than the design concentration, is also less than that, then this is the case only the introduction of fuel provided. The introduction can take place in the combustion chamber and / or the heat bed. In this way, a complete oxidation of the reactant is ensured even when falling below the minimum concentration. It can also be provided to dynamically adapt the minimum concentration of the oxidation system during operation. Thus, it may be advantageous to lower the minimum concentration at least temporarily to zero in order to ensure the reaction of the reactant only by heat from the heat storage. This can be done, for example, with a high amount of stored heat.

According to an advantageous development of the invention, with a below-average heat input but a concentration exceeding the minimum concentration, an autothermal operation is carried out with the release of heat from the heat accumulator into the heat bed and / or the combustion chamber. If the concentration of the reactant therefore lies between the minimum concentration and the design concentration of the system, autothermal operation of the system is nevertheless to be enabled, although this is not possible with below-average heat input in systems known from the prior art, since the concentration is less than the design concentration , For this purpose, heat is released from the heat storage. This can be done both in the warm bed and in the combustion chamber. By transferring the heat into the heat bed and / or the combustion chamber, the reactant is brought to the temperature required for its reaction, so that it can proceed without further ado. Thus, a complete oxidation or reaction of the reactant is made possible, although the temperature of the reactant can not be brought to the necessary temperature by means of the heat exchanger. With the heat emitted from the heat storage so the desired heat profile should be maintained in the heat bed of the heat exchanger. As already described, the minimum concentration can also be variably provided and, in particular, can be lowered to zero.

In a preferred development, the heat surplus is present at a concentration which is above a design concentration. The oxidation system is designed for the presence of a specific concentration, the design concentration. In this the autothermal operation is feasible. This means that from a concentration greater than this design concentration, more heat is introduced into the system, as can be recycled through the heat exchanger. In this case, therefore, there is the excess heat that can be used to load the heat accumulator.

Finally, it is provided that the reactant is a pollutant, in particular volatile hydrocarbon. The reactant must therefore not be discharged untreated into an environment of the system. It is therefore intended to carry out a reaction of the reactant in the system, in particular to oxidize it, so that no negative effects on the environment are exerted. The pollutant may be, for example, a volatile hydrocarbon such as is found in many processing industries, in particular paint processing industries.

An advantageous embodiment of the invention provides that a bed and / or at least one molding element as a heat bed is used, in particular, a ceramic material is provided. It can be provided to assemble the heat bed from at least one molding element, for example a honeycomb, which advantageously consists of ceramic. Al- ternative to the mold element and a bed is possible. The thermal bed may consist partly or entirely of a ceramic material. The ceramic material is highly heat resistant and has a low coefficient of expansion. This means that with varying temperature exposure of the heat bed no strong expansion or contraction of the material occurs. Therefore, with a ceramic heat bed, both the design of the system can be simplified, and their life, due to the high temperature resistance of the ceramic material can be increased.

The invention further relates to an oxidation plant, in particular thermal-regenerative exhaust air purification system, preferably for carrying out the method described above, with an intended average heat input by means of a present in varying concentration reactant, wherein the heat input a desired heat profile is maintained in at least one heat bed of a heat exchanger. In this case, a heat accumulator, in particular directly coupled to a combustion chamber of the oxidation system for charging, is provided, which serves to absorb excess heat and / or to give off heat, in particular in the case of a below-average heat input. With regard to the oxidation system, the above statements are also applicable. In the design of the oxidation plant, it is desirable, at an expected average concentration of the reactant one allow autothermal operation. If the concentration of the reaction substance is below this design concentration, heat is taken from the heat accumulator and fed to a combustion chamber or the heat bed of the oxidation system in such a way that a reaction of the reaction substance can take place.

According to a development of the invention, at least two heat beds are provided, wherein at least one first heat bed in front of a combustion chamber and at least one second heat bed are arranged after a combustion chamber. The heat exchanger thus has at least two heat beds, wherein a first fluidically provided before the combustion chamber and a second fluidically after this.

Conveniently, an alternating flow through the heat beds is provided. This means that the first heat bed and the second heat bed are alternately flowed through by the hot exhaust gas of the oxidation system and the reactant supplied thereto. During the throughflow with the exhaust gas, the respective heat bed is heated, whereas heat is given off to the latter during the passage through the reaction material, whereby the heating bed cools down. The reaction of the reaction substance can take place both in the combustion chamber and in the heat bed arranged in front of the combustion chamber.

Furthermore, it is provided that the heat accumulator is arranged substantially parallel to the second heat bed and in particular connected to the combustion chamber. The heat storage is thus fluidly operated in parallel to the heat bed. This means that an inlet of the heat accumulator also at the same time an inlet of the heat bed and an outlet of the heat accumulator can simultaneously be an outlet of the heat bed or these are fluidically connected to each other. The heat storage can therefore be connected as well as the second heat bed directly to the combustion chamber.

Finally, it is provided that a further system is connected to an exhaust gas connection of the system. The exhaust port can be in fluid communication both with the heat storage and with the second heat bed. The exhaust connection can therefore be fed by means of the heat storage but also by means of the second heat bed with heat, which is passed on to the other system. In this way, with the heat that is generated in the oxidation system, the other system can be operated and the heat can be used effectively.

The invention will be explained in more detail below with reference to the embodiments illustrated in the drawing, without any limitation of the invention. Show it:

FIG. 1 shows a schematic view of a thermal-regenerative exhaust-air purification system in a first operating mode,

2 shows the known from Figure 1 exhaust air purification system in another mode,

Figure 3 shows a first variant of the exhaust air purification system with heat storage and bypass device, and

Figure 4 shows another variant of the exhaust air purification system. 1 shows an oxidation system 1 in the form of an exhaust air purification system 1 ', which has a heat exchanger 2 in the form of three heat beds 3, 4 and 5, which are equipped for example with ceramic honeycomb bodies. The oxidation system 1 is used to clean with volatile hydrocarbons or the reaction substance contaminated exhaust air K, which is raw gas. The exhaust air K should therefore be freed from the hydrocarbons. For this purpose, it is passed through one of the heat beds 3, 4 or 5. FIG. 1 shows how the exhaust air K is passed through the thermal bed 4. The heat bed 4 is preheated to a high temperature, for example 800 ⁰ C. Subsequently, the exhaust air K enters a combustion chamber 6 of the exhaust air purification system 1 '. In the combustion chamber 6, a burner 7 is arranged, which can produce a flame 8. The burner 7 is intended to generate a support temperature in the combustion chamber 6. By applying the exhaust air K with the temperature prevailing in the heat bed 4, the hydrocarbons are oxidized, so that from the raw gas containing hydrocarbons, pure gas is, which has only oxidized, that is burned, hydrocarbons. The oxidation can take place both in the heat blanket 4 and only in the combustion chamber 6. The clean gas present in the combustion chamber 6 is then passed through the heat bath 5 in order to heat it up. Subsequently, the clean gas is discharged in accordance with the flow path 9 into an environment or outside atmosphere of the exhaust air purification system 1 '. By means of dashed flow paths it is indicated that in another operating mode it is also possible for clean gas to be passed through both the heat bed 5 and the heat bed 3. After a certain time, a Umtaktung, that is, the exhaust air K is no longer passed through the heat bed 4, but through the heat bed 3 or through the heat bed 5. Accordingly, the heat bed 4 is now used to pass the clean gas so that it heats up again, as it has previously given up heat to the raw gas.

In order to prevent raw gas from entering the clean gas during a transition from the raw gas operation of a heat bed 3, 4 or 5 into the clean gas operation, a so-called rinsing operation takes place. This is shown in FIG. Here, clean gas is passed in accordance with the flow path 10 from the combustion chamber 6 through a heat bed 3, 4 or 5, which has previously led raw gas. In the example shown, the clean gas is passed through the heat bed 3. This procedure serves to flush out crude gas residues, which are returned together with the clean gas into the loaded exhaust air flow K according to flow path 11. In this way, there is a cycle that is maintained until the heat bed 3 has no raw gas residues.

FIG. 3 shows a first variant of the exhaust air purification system 1 'in an operating mode in which the raw gas or exhaust air K first passes through the heat bed 4, enters the combustion chamber 6 and then passes through the heat bed 3. Parallel to the heat bed 3, a heat accumulator 11 is provided, which is bypassable by means of a bypass device 12, which is shown here as a control or controllable valve. The clean gas can thus from the combustion chamber 6 both through the heat bed 3 (flow path 9 ') and through the heat storage 11 (flow path 13) or past the heat storage 11 by the bypass device 12 (flow path 14) stream. In addition to the bypass device 12, a device may also be provided, by means of which the inflow from the combustion chamber 6 to the heat accumulator 11 is interrupted immediately. However, this is not shown in FIG. The clean gas is discharged either along the flow path 15 in the vicinity of the exhaust air purification system 1, or the pure gas flowing through the heat exchanger 11 or the bypass device 12 as indicated by the flow path 16, fed to another system 17. Alternatively, it is also possible to provide a supply of the clean gas which passes through the heat exchanger 2 or the heat bed 3 into the further system. The clean gas flowing along the flow paths 13 and / or 14 can also be combined at one or several points with the clean gas which flows along the flow path 9 '.

The exhaust air purification system 1 'has not shown fans and / or control flaps, with which the fluid (clean gas and / or raw gas) within the exhaust air purification system 1' can be moved. Different flow paths can be set via the flow flaps-for example, individual flow paths can be blocked-while the fans serve to transport the fluid.

It may be provided both, the further system 17th

To supply clean gas, which is the heat bed 3 or the

Heat storage 11, the thermal bed 3 or the bypass device 12 or only the heat bed 3 has passed through.

It can of course also be provided that the clean gas in addition to or as an alternative to the heat bed 3, the heat bed. 5 flows through. In this case, it is provided that the thermal bed 5 is also fluidly connected to the exhaust gas stream according to the flow path 9 ¹ .

The bypass device 12 is a so-called bypass. With this, the clean gas or exhaust gas, bypassing the heat accumulator 11, for example, be discharged directly from the combustion chamber 6 in the environment of the system or to the further system 17. The bypass device 12 can be controlled or regulated as a function of the temperature of the heat accumulator 11. In particular, the clean gas should be guided around it when a maximum temperature of the heat accumulator 11 is exceeded. This means that no overheating of the heat accumulator 11 can occur or that a loading of the heat accumulator 11 is interrupted as soon as the maximum temperature occurs or is detected in this.

Exhaust air purification systems 1 'known from the prior art are designed such that, given a concentration of the reaction substance which reaches at least one design concentration, an autothermal operation of the exhaust air purification system 1' can be carried out. This means that no additional fuel has to be introduced into the combustion chamber 6 by means of the burner 7, but that the heat of reaction of the reactant, for example the hydrocarbons, is sufficient to reach the reaction temperature of the reaction substance. For this purpose, the heat sinks 3, 4 and 5 must be dimensioned sufficiently large to allow the highest possible amount of heat from the exhaust gas or clean gas emitted from the combustion chamber 6 to the reaction chamber. supply raw material containing raw material, and in this way to increase its temperature as much as possible. It follows that the smaller the design concentration at which the exhaust air purification system V is operable, the larger the heat beds 3, 4 and 5 must be dimensioned.

The exhaust air purification system 1 'shown in FIG. 3 now has undersized heat beds 3, 4 and 5. This means that the heat sinks 3, 4 and 5 are made smaller than an autothermal operation requires at a design concentration. Instead, the exhaust air purification system 1 'is designed for a design concentration which is higher than a minimum concentration. Below the minimum concentration of additional fuel is added, at a concentration that is between minimum concentration and design concentration, however, heat is removed from the heat accumulator 11 to continuously continue the oxidation of the reactant. By contrast, in the systems known from the prior art, the design concentration essentially corresponds to the minimum concentration. It may therefore occur in these, when the concentration of the reactant falls below the design concentration, that by means of the heat exchanger 2, the reagent or the raw gas can not be brought to a temperature which is necessary for the oxidation of the reactant. In this case, there is a below-average heat input into the raw gas. The heat storage 11 is now provided to give off heat in the case of below-average heat input, in particular in the combustion chamber 6 and / or in the heat bed 3, to further allow a continuous reaction of the reactant without additional fuel through the burner 7 in the combustion chamber. 6 or in the To introduce heat sinks 3, 4 or 5. This means that when the heat input is below average, the heat stored in the heat accumulator 11 is used to increase the temperature of the raw gas, that is to say of the reactant.

Thus, the following modes of operation of the exhaust air purification system V are shown: At a concentration of the reaction substance below the minimum concentration of the exhaust air cleaning system V or the combustion chamber 6 and / or the heat beds 3, 4 and / or 5 additional fuel is supplied to allow oxidation of the reactant , At a concentration which is greater than or equal to the minimum concentration but less than the design concentration, heat stored in the heat accumulator 11 is returned to the combustion chamber 6 or one or more of the heat beds 3, 4 and 5, respectively. If the concentration corresponds to the design concentration, then the exhaust air purification system 1 'is in the autothermal operation, which means that neither additional fuel nor heat from the heat accumulator 11 must be supplied. If the concentration is higher than the design concentration, more heat is formed by the oxidation of the reaction substance than can be reacted with the aid of the heat exchanger 2. It creates a heat surplus. This heat surplus can be absorbed by the heat accumulator 11 and stored for later use. This means that at least part of the exhaust gas or of the clean gas from the combustion chamber 6 is used for heating the heat accumulator 11. If the heat accumulator 11 is completely loaded or if a temperature of the heat accumulator 11 exceeds a maximum temperature, then the heat accumulator 11 can be relieved by means of a bypass device 12 by relating the exhaust gas. hies the clean gas is guided around the heat storage 11. So there is no further loading of the heat storage 11th

The design of the exhaust air purification system 1 'is such that the heat sinks 3, 4 and 5 are undersized. While in a known exhaust air purification system Y, for example, an autothermal operation is provided at a concentration of 1, 1 g / m ³ , for which heat beds 3, 4 and 5 are necessary with a height of 2.0 m, according to the invention is a design of the exhaust air purification system Y on a Design concentration of 3 g / m ³ . In this way, heat beds 3, 4 and 5 with a height of, for example, 1, 5 m are sufficient. So far, only an optimization of the running in the exhaust air purification system Y process. Now, in addition, the process running in the other plant 17 should be considered, so that an optimization of the overall process comprising the two processes takes place. In this way, both the exhaust air purification system 1 'and the other system 17 can be operated with high efficiency and the lowest possible energy costs.

FIG. 4 shows a further variant of the exhaust-air purification system Y. Reference should first be made to the statements relating to FIG. 3 that apply here as well. In the example shown in FIG. 1, the further system 17 is a production device 18 which is fed directly, ie directly, with waste gas from the exhaust air purification system 1 ', as indicated by the flow path 16. The production device 18 consists of three hot air dryers 19, which are acted upon in parallel with the exhaust gas. After passing through the hot air dryer 19, the exhaust gas can again be contaminated with solvents or hydrocarbons. It will therefore, as by the Flow path 20 indicated again as exhaust air K of the exhaust air purification system 1 'fed to be cleaned there again.

Alternatively or in addition to the further system 17, a further heat exchanger 21 may be provided, which is arranged, for example, in terms of flow technology parallel to the heat accumulator 11. The heat exchanger 21 can be switched through in parallel to the heat storage 11 of exhaust gas from the combustion chamber 6. With the heat exchanger 21, a secondary circuit 22 associated fluid (for example, thermal oil, steam or the like) heated and a further system (not shown here) are supplied.

Via a connection 23, which is located on one of the combustion chamber 6 facing away from the fluid side of the heat accumulator 11, this fluid can be supplied. This fluid passes through the heat accumulator 11 in the direction of the combustion chamber 6 and thereby heats up, advantageously to a temperature which corresponds almost to the maximum temperature used when loading the heat accumulator 11. The heated fluid can now optionally the combustion chamber 6, the heat exchanger 21 and / or the other system 17 are supplied. In this way, both the reaction of the reactant in the combustion chamber 6 can be maintained, as well as the secondary circuit 22 by means of the heat exchanger 21 and the further system 17 further heat are supplied.

If the fluid is to be supplied to the further system 17, then the heated fluid must be brought to a temperature which is suitable for the operation of the further system 17. This can be done by the fluid is first passed through the heat exchanger 21, wherein the fluid withdrawn heat and thus it is brought to a lower temperature. Alternatively, however, it is also possible to displace the heated fluid with cooler fluid and thus adjust its temperature so that it can be supplied to the further system 17. In this way, the further system 17 can be continuously supplied with heat, should the amount of heat generated in the exhaust air purification system V be insufficient.

Claims

claims 1. A method for operating an oxidation system (1), with an intended average heat input by means of a present in varying concentrations of reactant, wherein the heat input a desired heat profile in at least one heat bed (3,4,5) of a heat exchanger (2) is maintained, characterized by a, in particular directly to a combustion chamber (6) of the oxidation system (1) coupled for charging, heat accumulator (11) for receiving heat surplus and / or release of heat, in particular in the case of a below-average heat input. 2. The method according to claim 1, characterized in that the system (1) in particular in the heat storage (11) stores stored heat to at least one other system (17). 3. The method according to any one of the preceding claims, characterized in that the temperature of the further system (17) for heat dissipation supplied fluid is controlled and / or regulated. 4. The method according to any one of the preceding claims, character- ized in that as another system (17) another Heat exchanger (21), a heater, a production device (18), a refrigerator or a power converter device is used. 5. The method according to any one of the preceding claims, character- ized in that a reaction of the reactant in the heat bed (3,4,5) and / or the combustion chamber (6) expires, wherein by means of the heat exchanger (2) of the heat bed (3,4,5) and / or the combustion chamber (6) supplied with heat from heat the combustion chamber (6) effluent exhaust gas is heated. 6. The method according to any one of the preceding claims, characterized in that at least a portion of the exhaust gas is used in addition to the heating of the heat accumulator (11). 7. The method according to any one of the preceding claims, character- ized in that the heat storage (11) is heated to almost the highest in the oxidation system (1) present temperature. 8. The method according to any one of the preceding claims, characterized in that as a heat storage (11) a long-term heat storage is used. 9. The method according to any one of the preceding claims, characterized in that at a concentration which is below a minimum concentration, additional fuel in the combustion chamber (6) and / or the heat bed (3,4,5) is introduced. 10. The method according to any one of the preceding claims, characterized in that at below average heat input but a concentration exceeding the minimum concentration autothermal operation with release of heat from the heat storage (11) in the heat bed (3,4,5) and / or the combustion chamber (6) is performed. 11. The method according to any one of the preceding claims, characterized in that at a concentration which is above a design concentration, the excess heat is present. 12. The method according to any one of the preceding claims, character- ized in that the reactant is a pollutant, in particular volatile hydrocarbon. 13. The method according to any one of the preceding claims, characterized in that a bed and / or at least one mold element is used as a heat bed (3,4,5), in particular a ceramic material is provided. 14. Oxidation plant (1), in particular thermal-regenerative exhaust-air purification plant (1 '), preferably for carrying out the process according to one or more of the preceding claims, with an intended average heat input by means of a present in varying concentration reactant, wherein by the heat input desired heat profile in at least one heat bed (3,4,5) of a heat exchanger (2) is maintained, characterized by a, in particular directly to a combustion chamber (6) of the oxidation system (1) coupled for charging, heat storage (11) for receiving excess heat and / or release of heat, in particular in the case of a below-average heat input. 15. Oxidation plant according to claim 14, characterized in that at least two heat beds (3,4,5) are provided, wherein at least one first heat bed (4) in front of a combustion chamber (6) and at least one second heat bed (3,5) are arranged after a combustion chamber (6). 16. Oxidation plant according to one of the preceding claims, characterized in that an alternating flow through the heat beds (3,4,5) is provided. 17. Oxidation plant according to one of the preceding claims, characterized in that the heat accumulator (11) is provided substantially parallel to the second heat bed (3,4,5) and in particular to the combustion chamber (6) is connected. 18. Oxidation plant according to one of the preceding claims, characterized in that a further system (17) is connected to an exhaust port of the system.