Retrofit assembly for treatment plant and method for retrofitting treatment plant

Abstract

A retrofit assembly (202) suitable for retrofit of a treatment plant, in particular an existing treatment plant, for treating workpieces, in particular drying vehicle bodies, in which the retrofit assembly (202) comprises:-one or more auxiliary heating devices (206, 208, 210), the heating device is suitable for heating clean gas guided in the clean gas guide part (126) and / or fresh air guided in the fresh air guide part (122); and a) a regenerative thermal oxidation device (204) replacing a hot post-combustion device (142), in particular heated by fossil fuel; or b) a regenerative thermal oxidation device (204) in place of the fresh air heat exchanger (144), and a retrofit thermal post-combustion device (142) used as a fresh air heat exchanger (150), in particular heated by fossil fuel; or c) instead of a regenerative thermal oxidation device (204), in particular a hot post-combustion device (142) heated by fossil fuel, and an electrically heated circulating air module (214) instead of a circulating air module (110) with a heat exchanger or a retrofit circulating air module (214) with an electrically heated regulator rather than a heat exchanger.

Description

Technical Field

[0001] The invention relates to a retrofitting assembly for retrofitting a processing device, in particular an existing processing device, for processing workpieces, in particular drying vehicle bodies, and also to a method for retrofitting a processing device. Background Art

[0002] In the fight against global warming, more and more automobile manufacturers are considering switching existing treatment plants or drying plants in the body area from heating with fossil fuels (natural gas, oil, etc.) to heating with the aid of electricity from renewable energy sources.

[0003] The prior art for heating such drying plants (or dryers for short) is the combination of exhaust gas purification and heating. Here, the remaining waste heat of the purified dryer exhaust gas (also referred to as clean gas) is used in a downstream heat recovery system for heating the circulating air in the circulating air units or modules of the individual dryer zones or sections and for heating the fresh air in the fresh air units or heat exchangers before the exhaust gas is subsequently discharged to the atmosphere (via the roof).

[0004] For technical ventilation of the drying system in the vehicle body area, it is provided that the dryer atmosphere (exhaust air) containing solvent is constantly replaced by a solvent-free fresh air flow. For this purpose, an exhaust air volume flow is obtained at one or more locations in the treatment chamber or drying tunnel by means of an exhaust air fan and supplied to a device for exhaust gas purification, usually a thermal afterburner (TAR) for waste heat utilization.

[0005] When using TAR, the purified exhaust gas volume flow, ie the clean gas, has a temperature of approximately 450° C. for the dryer heating.

[0006] The individual dryer sections are heated via a circulating air module with its own heat exchanger, while the clean gas flow is cooled along the clean gas duct connecting the circulating air modules. Finally, the clean gas flow flows through a fresh air heat exchanger and leaves the drying plant via the roof at a temperature of, for example, 130°C.

[0007] Alternatively or in addition, circulating air modules can be considered which each include a separate combustion device or are connected to such a separate combustion device, whereby the circulating air modules are configured so that they can heat the corresponding local circulating air flows which are guided through the corresponding associated process chamber sections in the local circulating air guides.

[0008] The minimum exhaust gas volume flow is determined by criteria based on the lower explosion limit, but is correspondingly higher in practice, so that the energy requirement of the dryer can be met by the clean gas enthalpy flow.

[0009] When the drying plant is converted from heating by fossil fuels to electric heating it is obvious that direct heating with electricity can be used.

[0010] Direct heating converts electrical energy into thermal energy. For this purpose, the current flows into a heating coil or heating wire. There, a resistance is generated, which in turn generates heat. The heat is discharged via a heat conductor, such as a heating fin, directly to the air flow to be temperature-controlled (e.g. circulating air or fresh air).

[0011] Heating by means of fossil fuels is accompanied by an exhaust gas stream containing pollutants such as nitrogen oxides, which must not enter the dryer atmosphere since they have a negative impact on the quality of the paint.

[0012] For this reason, drying plants heated by fossil fuels are equipped with an indirect heating section, in which the thermal energy of the flue gases, i.e. the gaseous combustion products during the technical combustion of the fuel, or the thermal energy of the clean gases of a centralized exhaust gas purification or recovery device is transferred to the dryer atmosphere consisting of circulating air and fresh air by means of heat exchangers, in particular connected in series, which are preferably integrated into the circulating air module, without any mixing of substances of the two media occurring, i.e. the flue gases or clean gases are not mixed with the circulating air or fresh air.

[0013] If such a system heated by fossil fuels is to be converted to electrical heating, it is known from the prior art and new systems to remove existing system components for indirect heat transfer and to replace them with electrical heating controllers.

[0014] These electric heating controllers are then installed, for example, as decentralized heat sources in circulating air units and / or fresh air units.

[0015] The purification of the dryer exhaust gas is then carried out separately from the drying heating. Often, thermal methods are also used here to purify the exhaust gas containing solvents and odors.

[0016] These processes can be brought to operating temperature using fossil fuels or with the aid of electrical energy. Once the system has reached operating temperature, it is usually based on the solvent content. Self-sufficient adiabatic operation requires only the heat released by the oxidation of the solvent.

[0017] However, it is known from practice that when converting a drying plant from heating by means of fossil fuels to electrical heating, the design concept used when setting up the new plant is to be used.

[0018] In the case of existing devices, these design solutions have the following disadvantages and problems.

[0019] The installation of decentralized electric heating, in which each circulating air and fresh air unit is equipped with its own electric heating controller, requires extensive mechanical modification work on the individual units, since in particular the clean gas heat exchanger must be replaced by the electric heating controller. In addition, the individual circulating air units require extensive electrical installation work, including the positioning of the switch cabinet with the heating controller attached and the positioning of the distribution station with the low-voltage equipment attached.

[0020] Furthermore, in decentralized electrical heating processes, the placement or location of one or more distribution substations for supplying the individual heating regulators determines to a large extent the length of the cables to the individual heating regulators and the costs associated therewith.

[0021] Furthermore, especially in existing systems there is little free installation space.

[0022] Furthermore, the conversion also means the removal of the existing heating concept, i.e. the removal of the clean air ducting along the entire length of the dryer, the removal of the clean air channels and flaps in the area of ​​the circulating air / fresh air unit and possibly the removal of the exhaust air duct to the TAR, depending on where the new exhaust air purification section should or can be installed.

[0023] Another factor to be considered is the considerable time and economic cost of the conversion, since such conversion or reconstruction is difficult to achieve during the shutdown phase and also requires sufficient manpower. Summary of the invention

[0024] An object of the present invention is to provide a retrofit assembly which can efficiently retrofit a processing device into an electric heating section.

[0025] According to the present invention, this object is achieved by a retrofit assembly having the following technical solutions.

[0026] The retrofitting assembly according to the invention is used or suitable for retrofitting a processing device, in particular an existing processing device, for processing workpieces, in particular for drying vehicle bodies.

[0027] The retrofit kit according to the present invention comprises:

[0028] one or more auxiliary heating devices, which are suitable for warming the clean air guided in the clean gas duct and / or the fresh air guided in the fresh air duct; and

[0029] a) a regenerative thermal oxidizer replacing a thermal afterburner, in particular one heated by fossil fuels (hereinafter also referred to as case a)); or

[0030] b) regenerative thermal oxidizers replacing fresh air heat exchangers and thermal afterburners used as retrofits of fresh air heat exchangers, in particular heated by fossil fuels (hereinafter also referred to as case b)); or

[0031] c) Regenerative thermal oxidation devices replacing thermal afterburning devices, in particular heated by fossil fuels, and electrically heated circulating air modules replacing circulating air modules with heat exchangers or retrofitted circulating air modules with electrical heating regulators instead of heat exchangers (hereinafter also referred to as case c)).

[0032] The processing equipment to be retrofitted, which is preferably or comprises an existing processing equipment with a retrofittable basic structure, has a conveying direction and comprises:

[0033] a process chamber comprising a plurality of process chamber sections, each of which is associated with a separate circulating air module, each of which comprises a heat exchanger;

[0034] an exhaust gas duct which conducts exhaust gas out of the process chamber;

[0035] a thermal aftercombustion device, in particular heated by fossil fuels, for recovering, in particular cleaning, the exhaust gases, which is provided for retrofitting or replacement;

[0036] a clean gas duct which conducts purified exhaust gas, in particular clean gas, wherein the clean gas duct preferably extends at least approximately parallel to the conveying direction; and

[0037] - A fresh air supply which supplies fresh air to the process chamber.

[0038] Furthermore, the process chamber preferably comprises a pre-processing chamber, which is arranged in front of the process chamber with reference to the transport direction, and / or a post-processing chamber, which is arranged behind the process chamber with reference to the transport direction.

[0039] The invention is based on the basic idea of ​​keeping the modification effort for the treatment plant as low as possible and continuing to use or reusing existing plants as much as possible. Accordingly, the modification to electric heating is not for direct heating, but for making existing indirect heating compatible with electric heating.

[0040] Consistently, the TAR, which has hitherto been heated by fossil fuels, is replaced by an electrically powered and thus flameless regenerative thermal oxidizer (F-RTO), which preferably comprises a single-bed exhaust gas purification section and the dryer exhaust gas is used as heat transfer medium for the electrical heating.

[0041] Furthermore, it is thus possible to continue to use the clean gas infrastructure, in particular for central and indirect electric dryer heating.

[0042] For the F-RTO, different positions within the processing equipment can be considered. On the one hand, the F-RTO can be positioned in the heat path. The F-RTO can be located at the beginning of the heat transfer path, i.e. directly after the exhaust gas is discharged from the dryer, wherein the temperature stroke of the exhaust gas purification serves to heat the exhaust gas by about 20 K. The heat recovery unit is located at the end of the fresh air unit, ie after the fresh air unit or the fresh air heat exchanger, wherein the temperature stroke is then utilized by means of further heat recovery measures.

[0043] It is particularly advantageous that the F-RTO comprises a single electrically heated bed placed horizontally and the flow direction can be periodically reversed via a disk valve. During the flow through the bed, preheating is achieved up to the core, which allows the chemical conversion to take place without supplying combustion gas. The gas is then cooled in the other half of the bed.

[0044] It may be advantageous if the F-RTO is operated adiabatically once the solvent concentration exceeds a certain limit. In the case of an adiabatic reaction, for example at 1 g / m 3 At a solvent concentration of 100 Å, a temperature of about 20 K can be achieved, wherein the temperature achieved increases with increasing solvent concentration. F-RTO can preferably act catalytically here.

[0045] Preferably, all electrically operated heating components of the converted treatment plant (such as in particular electrically operated auxiliary heating devices) can be supplied with an average voltage of, for example, at least about 3 kV and / or at most about 8 kV, in particular 4160 V to 6600 V, instead of the usual 400 V. Although this may require special heating elements with corresponding additional costs, it preferably provides enormous savings possibilities in the periphery (i.e. with respect to connectors, cables, etc.). In addition, the necessity of factors from the transformer section of the power supply network is significantly reduced, which in particular reduces the investment costs for the transformer substation and saves space. The attachment of electrically operated heating components with such an average voltage also allows a significant reduction in the cable diameter.

[0046] In one embodiment of the present invention, it can be provided that the process installation to be converted further comprises a fresh air heat exchanger which is designed to transfer the heat energy contained in the clean gas to the fresh air supplied to the process installation.

[0047] In a further embodiment of the invention, it can be provided that one or more auxiliary heaters are purely electrically operated, hydrogen operated or thermal oil operated auxiliary heaters.

[0048] However, in the case of auxiliary heaters operated with thermal oil, corresponding upper temperature limits must be observed.

[0049] In a further embodiment of the invention, it can be provided that the regenerative thermal oxidizer is a purely electrically operated, flameless regenerative thermal oxidizer.

[0050] In a further embodiment of the invention, it can be provided that one or more purely electrically operated auxiliary heating devices and / or purely electrically operated, flameless regenerative thermal oxidizers can be connected to a central electrical connection point, in particular a power distribution station.

[0051] The central electrical attachment point not only saves installation space but also reduces costs.

[0052] In another embodiment of the present invention, it can be provided that the regenerative thermal oxidizer includes a Ventilator for air flow.

[0053] In a further embodiment of the invention, it can be provided that in case b) of replacing the fresh air heat exchanger with a regenerative thermal oxidizer, a thermal afterburner of the process plant, in particular heated by fossil fuels, can be used as a fresh air heat exchanger, in particular after retrofitting.

[0054] The old TAR is used as a new fresh air heat exchanger at its previous installation location. The TAR of the treatment plant has been used as a recovery device after the conversion, and its effective internal heat exchanger is used for fresh air warming at the end of the exhaust air path.

[0055] In a further embodiment of the invention, provision can be made for the clean gas in case c) to be conducted only to the fresh air heat exchanger by means of the clean gas conduction, ie in particular the clean gas is not conducted through the circulating air module.

[0056] In a further embodiment of the invention, it can be provided that in cases a) and c) a flow can flow through the clean gas guide in the conveying direction.

[0057] Existing treatment plants are also known in which the TAR is located in the region of the outlet of the treatment chamber and, conversely, the fresh air heat exchanger is arranged in the region of the inlet. In this arrangement, the modification of the plant according to cases a) and c) still results in a further flow through the clean gas guide in the opposite direction of the conveying direction.

[0058] However, in another embodiment of the invention it can be provided that in case b) a flow through the clean gas guide can be directed counter to the conveying direction.

[0059] In a further embodiment of the invention, it can be provided that the regenerative thermal oxidizer is arranged at the end of the clean gas duct with reference to the conveying direction.

[0060] In a further embodiment of the invention, it can be provided that the fresh air heat exchanger is designed as a thermal oil circuit or a circuit combination system.

[0061] This design of the fresh air heat exchanger is particularly advantageous when the oxidation device is arranged too far away from the treatment chamber, for example outside a building, because the transferable and potential thermal energy can be efficiently transferred from the exhaust gas flow located further away to the fresh air required for the treatment chamber by means of a hot oil circuit or a circuit combination system.

[0062] Alternatively or additionally, provision can be made for one or more high-temperature auxiliary heating devices or high-temperature auxiliary heating controllers to be arranged downstream of the oxidation device.

[0063] The high-temperature auxiliary heating device comprises an electric heating element preferably in the form of a tube or round tube heating body, or is designed as such an element, wherein heat is generated in a heating conductor through which an electric current passes. The heating conductor is preferably embedded centrally in a highly compressed magnesium oxide layer, thereby achieving a high degree of electrical isolation with good thermal conductivity.

[0064] By means of one or more high-temperature auxiliary heaters, the purified exhaust gas or clean gas can be heated to a temperature of 450° C. to 480° C., thus providing a clean gas temperature for dryer heating that is similar to that available hitherto when using TAR in process plants.

[0065] Such a high-temperature auxiliary heating device is preferably arranged in a suspended manner in the processing device, thereby avoiding friction due to the action of normal forces, as is the case with a conventional horizontal and abutting arrangement of the tubes.

[0066] A plurality of high-temperature auxiliary heating devices are preferably arranged in series, wherein when more than one high-temperature auxiliary heating device is used, these devices are preferably constructed similarly, i.e., in particular have a power of, for example, 1 W / cm 2 Up to 2W / cm 2 Using the same high temperature auxiliary heating device minimizes the number of parts that may need to be replaced.

[0067] The invention also aims at providing a method which enables a treatment plant, in particular an existing treatment plant, to be converted into an electrically heated treatment plant with reduced exhaust gas.

[0068] According to the present invention, this object is achieved by a method according to the following technical solution.

[0069] Preferably, the conversion method is based on a processing device to be converted for processing workpieces, in particular drying vehicle bodies, which has a conveying direction and comprises:

[0070] a process chamber comprising a plurality of process chamber segments, each of which is associated with a separate circulating air module, each of which comprises a heat exchanger;

[0071] an exhaust gas duct which conducts exhaust gas out of the process chamber;

[0072] a thermal aftercombustion device, in particular heated by fossil fuels, for recovering, in particular cleaning, the exhaust gases, which is provided for retrofitting or replacement;

[0073] a clean gas duct which conducts purified exhaust gas, in particular clean gas;

[0074] a fresh air heat exchanger which transfers the heat energy contained in the clean gas to the fresh air supplied to the treatment plant; and

[0075] A fresh air supply which supplies fresh air to the process chamber via a fresh air heat exchanger.

[0076] The method comprises the following steps:

[0077] - installing one or more auxiliary heating devices in the clean air duct and / or the fresh air supply; and

[0078] a) Replacement of the heat recovery unit by a regenerative thermal oxidizer; or

[0079] b) Replacement of the fresh air heat exchanger by a regenerative thermal oxidizer and conversion of the thermal afterburning plant, in particular heated by fossil fuels, for use as a fresh air heat exchanger; or

[0080] c) The heat recovery device is replaced by a regenerative thermal oxidizer and the circulating air module with the heat exchanger is replaced by an electrically heated circulating air module, or the heat exchanger of the circulating air module is replaced by an electrically heated regulator.

[0081] Preferably, the method has one or more of the features and / or advantages described in conjunction with the retrofit assembly.

[0082] Preferably, the retrofit assembly also has one or more of the features and / or advantages described in conjunction with the method.

[0083] In the second alternative of case c), the previous circulating air module is retained, ie preferably remains in place, and the corresponding heat exchanger is preferably replaced by an electric heating controller.

[0084] In one embodiment of the invention, it can be provided that one or more purely electrically operated, hydrogen-operated or thermal oil-operated auxiliary heating devices and / or purely electrically operated, preferably flameless, regenerative thermal oxidizers are connected to a central electrical connection point, in particular a power distribution station.

[0085] In a further embodiment of the invention, it can be provided that in case b) the thermal afterburning device of the process plant to be converted, in particular heated by fossil fuels, continues to be used as a fresh air heat exchanger.

[0086] In a further embodiment of the invention, it can be provided that in cases a) and c) the clean gas flows through the clean gas duct in the conveying direction.

[0087] In one embodiment of the invention, it can be provided that in case b) the clean gas flows through the clean gas guide counter to the conveying direction.

[0088] In one embodiment of the present invention, it can be provided that the exhaust gas is at least partially or at least nearly completely guided through a purely electrically operated, preferably flameless, regenerative thermal oxidizer and is at least temporarily heated there to a temperature at which substances contained in the air flow, in particular solvents, undergo a chemical conversion, and at least a portion of the heat temporarily contained in the exhaust gas is utilized as waste heat so that the clean gas leaves the purely electrically operated, preferably flameless, regenerative thermal oxidizer at a temperature between the input temperature and the temporary maximum temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Further preferred features and / or advantages of the invention are the subject matter of the following description of exemplary embodiments and of the drawings.

[0090] In the accompanying drawings:

[0091] Figure 1 It is a schematic diagram of the basic structure of the processing equipment;

[0092] Figure 2 is a schematic diagram of a first embodiment of a modified processing device;

[0093] Figure 3 is a schematic diagram of a second embodiment of a modified processing device;

[0094] Figure 4 is a schematic diagram of a third embodiment of a modified processing device;

[0095] Figure 5 is a schematic diagram of a fourth embodiment of a modified processing apparatus;

[0096] Figure 6 is a schematic diagram of a fifth embodiment of a modified processing apparatus; and

[0097] Figure 7 is a schematic diagram of the air attachment of the oxidation device.

[0098] Identical or functionally equivalent elements are provided with the same reference symbols in all figures. DETAILED DESCRIPTION

[0099] Processing equipment, especially existing processing equipment Figure 1 The basic structure shown in FIG. 1 and designated as a whole by 100 is used for processing workpieces (not shown), in particular for drying vehicle bodies.

[0100] The treatment plant basic structure 100 is in particular the basic structure of a dryer 102 for drying previously coated vehicle bodies.

[0101] The basic structure 100 of the processing device should be understood as the basis of the processing device, which is the basis for the modification or its components are continued to be used and / or functionally and / or structurally integrated in the modified device. Therefore, all components of the basic structure 100 of the processing device should also be understood as being contained in the processing device, especially in the existing processing device.

[0102] The processing equipment basic structure 100 includes a processing chamber 104 and a post-processing chamber 106 .

[0103] The processing chamber 104 includes a plurality of processing chamber sections 108 .

[0104] The process chamber segment 108 is associated with a plurality of individual circulating air modules 110 of the treatment system 100 .

[0105] The circulating air modules 110 cause partial circulating air flows 112 in partial circulating air ducts 114 to flow through the respectively associated process chamber segments 108 .

[0106] The circulating air modules 110 preferably each include a ventilator and a heat exchanger.

[0107] The workpieces to be processed, in particular vehicle bodies, are transported along a transport direction 116 through the processing chamber 104 and the post-processing chamber 106 .

[0108] The treatment chamber 104 further comprises an inlet lock 118 and / or an outlet lock 120 , which are supplied with preferably preheated fresh air via a fresh air duct 122 in order to form an air path.

[0109] It is also conceivable that the fresh air duct 122 is additionally or alternatively connected to at least one of the circulating air modules 110 or that it supplies fresh air to at least one circulating air module 110 .

[0110] The exhaust gas is preferably conducted centrally out of the process chamber 104 via an exhaust gas duct 124 .

[0111] The recovered exhaust gas or clean gas is guided through the clean gas guide 126 .

[0112] The clean gas duct 126 is thermally coupled to the circulating air module 110 , so that the thermal energy contained in the clean gas can be transferred to the local circulating air flow 112 .

[0113] The post-processing chamber 106 is attached to the process chamber 104 along a transport direction 116 .

[0114] However, it is also conceivable that a cooling zone (not shown) is arranged between the post-processing chamber 106 and the process chamber 104 , in which the temperature of the processed workpiece is actively and / or passively reduced.

[0115] The post-processing chamber 106 includes a plurality of post-processing chamber segments 128 .

[0116] The aftertreatment chamber 106 is associated with a fresh air heat exchanger 130 which transfers the heat energy contained in the exhaust gas flow 132 to a supplied fresh air flow 134. However, it may be more common to mix a partial flow from the exhaust gas flow 132 into the fresh air flow 134.

[0117] From the fresh air heat exchanger 130 , a preheated fresh air flow 136 is supplied to one of the aftertreatment chamber sections 128 .

[0118] A circulating air flow 138 is formed between the aftertreatment chamber sections 128 .

[0119] After transferring at least part of the thermal energy, the exhaust gas flow 132 is led off downstream of the fresh air heat exchanger 130 as a cooled exhaust gas flow 140. The part of the exhaust gas which is not reused leaves the treatment device 100 via the roof, while the exhaust gas is mixed into the fresh air flow.

[0120] Processing device 100 Figure 1 The basic structure shown in Figures 2 to 6 The basis for describing the conversion components or the conversion method steps is formed in.

[0121] The basic structure 100 of the existing processing equipment or the equipment infrastructure and the corresponding components that continue to be used after the modification are Figures 1 to 6 100 are shown as dashed marks or shown in dashed lines. The schematic positions of the components that are replaced or substituted during the modification process are shown as dashed marks or shown in dashed lines in the figure. In addition, the components of the basic structure 100 of the processing device are marked with reference numbers in the range from 100 to 199, while the modified components or new components are marked with reference numbers in the range of greater than or equal to 200.

[0122] exist Figure 2 A first embodiment of a retrofitted treatment plant 200 is shown in FIG. 2 , which is retrofitted with a retrofit assembly 202 .

[0123] In the modified processing equipment 200 Figure 2In the embodiment shown, the exhaust gas from the process chamber 104 is conducted via an exhaust gas duct 124 and supplied to a purely electrically operated, preferably flameless, regenerative thermal oxidizer 204 .

[0124] The oxidation device 204 replaces the previously used thermal afterburning device 142 , which was heated in particular by fossil fuels, at the corresponding location.

[0125] In particular, the post-combustion device 142 heated or warmed by fossil fuels is therefore replaced by an electrically heated oxidizer 204 , and the temperature rise resulting from the purification or recycling of the exhaust gas in the oxidizer 204 is used to heat the process chamber section 108 .

[0126] The recycled exhaust gas or clean air is additionally heated downstream of the oxidation device 204 by an electrically operated auxiliary heating device 206 , so that the heat input to the partial circulation air flow 112 is sufficient for processing the workpieces, ie, in particular, for drying the vehicle body.

[0127] If necessary, further electrically operated auxiliary heating devices 208 can be arranged between the circulating air modules 110 in order to provide sufficient thermal energy for the partial circulating air flows 112 over the entire length of the process chamber 104 .

[0128] The arrangement of further electrically operated auxiliary heaters 208 between the circulating air modules 110 also avoids excessively high heating outputs and the consequently excessively high surface temperatures at the electrically operated auxiliary heaters 206 .

[0129] The clean gas flows through the clean gas duct 126 in the conveying direction 116 and transfers its heat energy to the supplied fresh air 146 in a fresh air heat exchanger 144 , which can in particular be part of the treatment plant base structure 100 , in order to then be discharged through the roof as a cooled clean gas flow 148 .

[0130] A throttle valve (not shown) is also used in the region of the fresh air heat exchanger 144 and the circulating air module 110 .

[0131] Preferably, a further electrically operated auxiliary heating device 210 is arranged in the fresh air duct 122 in order to be able to discharge the purified exhaust gas or clean air after the fresh air heat exchanger as a cooled clean air flow 148 with a low temperature into the atmosphere or via the roof.

[0132] For this purpose, the enthalpy flow through the roof should be kept as low as possible, which is why it is recommended to preheat only the fresh air by means of the fresh air heat exchanger 144. The remaining required temperature range is then achieved by means of a further electrically operated auxiliary heating device 210 during direct heating of the fresh air flow in the fresh air duct 122.

[0133] The electrically operated auxiliary heater 210 in the fresh air duct 122 also assumes other functions and in particular regulates temperature fluctuations of the fresh air which occur during the required periodic reversal of the flow direction through the individual beds of the oxidation device 204 .

[0134] The fresh air, which has been temperature-controlled in a suitable manner, is ultimately supplied to the inlet lock 118 and / or the outlet lock 120 , preferably via a fresh air supply 122 , and from there is conveyed into the local circulating air flow 112 of the process chamber segment 110 .

[0135] exist Figure 3 A second embodiment of a treatment device 200 retrofitted with a retrofit assembly 202 is shown in FIG.

[0136] In this embodiment, the exhaust gas duct 124 conducts the exhaust gas discharged from the process chamber 104 through a purely electrically operated, flameless, regenerative thermal oxidizer 204 , which now replaces the fresh air heat exchanger 144 .

[0137] An electrically operated auxiliary heating device 206 is likewise arranged downstream of the oxidation device 204 , which further heats the clean gas after the oxidation device 204 .

[0138] Downstream of the oxidation device 204 or the electrically operated auxiliary heating device 206 , the clean gas flows through the clean gas duct 126 in the opposite direction of the conveying direction 116 through alternative replacement positions within the treatment device 200 , wherein the thermal energy of the clean gas guided in the clean gas duct 126 is also transferred here to the local circulating air flow 112 by means of the heat exchanger of the circulating air module 110 .

[0139] Likewise, in the second embodiment it is preferably also provided that further electrically operated auxiliary heating devices 208 are arranged along the clean gas line, ie in particular between the circulating air modules 110 .

[0140] As an alternative to the first embodiment, the thermal afterburning device 142, which has been operated in the existing process plant and is heated, in particular by fossil fuels, is not completely replaced but rather rebuilt, i.e. the afterburning is stopped and the internal heat exchanger of the afterburning device 142 is used as a fresh air heat exchanger 150 to transfer the remaining heat energy of the clean gas downstream of the circulating air module 110 to the required supply fresh air flow 152. Thus, the usually high-quality and very efficient heat exchanger of the afterburning device 142 can be put to continued use.

[0141] The clean gas, which is cooled due to the heat transfer, is directed out to the atmosphere as a cooled clean gas stream 154 or through the roof.

[0142] Downstream of the fresh air heat exchanger 150 , the preheated fresh air is raised by means of further additional devices 210 to the temperature which is preferably required for the inlet lock 118 and / or the outlet lock 120 .

[0143] Thus, as a result of the conversion, the oxidation device 204 replaces the fresh air heat exchanger 144 of the existing plant at its original location, while the thermal afterburning device 142, in particular heated by fossil fuels, remains in its place in a very effortless and cost-effective manner and is merely modified so that its internal heat exchanger can be used as fresh air heat exchanger 150.

[0144] However, the reversal of the flow direction in the clean gas duct 126 requires an adaptation of the exhaust gas duct 124 , which must be widened by remodeling the exhaust gas duct 212 , so that the exhaust gas can be guided to an alternative installation location of the oxidation device 204 instead of the original fresh air heat exchanger 144 .

[0145] It is also conceivable that a pretreatment chamber is located upstream of the process chamber 104 with respect to the transport direction 116 , in which the workpieces are pretreated in one or more pretreatment chamber sections, wherein each pretreatment chamber section is respectively associated with a separate circulating air module.

[0146] The pretreatment chamber, which is supplied with fresh air, can have its own inlet and / or outlet lock or an intermediate lock.

[0147] For a converted processing device 200 , it may be necessary to arrange a further electrically operated auxiliary heating device 208 at or in the clean gas duct 126 in order to also be able to transfer sufficient thermal energy for heat transfer from the clean gas to the partial circulation gas flow 112 in the region of the pretreatment chamber section.

[0148] However, the temperature level required in the pretreatment chamber is usually lower than the temperature level in the treatment chamber, which is why further electrically operated auxiliary heating devices 208 can be omitted between the circulating air modules 110 associated with the pretreatment chamber segments.

[0149] In other respects, the retrofitting of an existing treatment system with a pretreatment chamber is similar to that of a system without a pretreatment section, primarily also because the air or gas conduction required for the pretreatment chamber is already present.

[0150] Processing device 200 retrofitted with retrofit component 202 Figure 4 The third embodiment shown differs from the first embodiment in that, although the thermal afterburner 142 , which is heated in particular by fossil fuels, is likewise replaced by a purely electrically operated, flameless, regenerative thermal oxidizer 204 , the position thereof is different.

[0151] The original afterburner 142 Figure 4 is stopped and crossed in the position shown, or is removed from that position.

[0152] The oxidation device 204 is arranged downstream of the circulating air module 110 and upstream of the fresh air heat exchanger 144 .

[0153] For example, the installation of the oxidation device 204 at a position different from the original afterburning device 142 may be limited due to space reasons, which should also be understood to mean that the freed-up space volume at the position of the original afterburning device 142 can be used, for example, for transformer infrastructure, i.e. in particular for an integrated unit consisting of a central electrical heat generating unit and a central transformer unit.

[0154] In a third embodiment, similar to the first embodiment or opposite to the second embodiment, the exhaust gas is guided along the conveying direction 116 through the clean gas guide section 126, wherein an electrically operated auxiliary heating device 206 is also arranged downstream of the process chamber 104 and / or other electrically operated auxiliary heating devices 208 are arranged between the circulating air modules 110 to additionally heat the exhaust gas flow and thereby ensure that the thermal energy input into the local circulating air flow 112 is sufficient for workpiece processing.

[0155] Figure 5 A fourth embodiment of an existing processing plant 200 retrofitted with a retrofit assembly 202 is shown.

[0156] The fourth embodiment should be understood as Figure 4 A variation of the third embodiment is shown, in which it is assumed in the fourth embodiment that the oxidation device 204 is arranged only very far away from the process chamber 104 , ie outside the building boundary 156 .

[0157] Therefore, using the exhaust gas enthalpy flow in the fresh air heat exchanger 144 would require high costs in terms of additional length in the exhaust gas line, ie, additional channel length, and would possibly also require additional insulation of the exhaust gas line downstream of the circulating air module 110 .

[0158] For this reason, a thermal oil circuit 213 or a circuit combination system (KVS) is used here, with the help of which the transferable and potential heat can be transferred from the exhaust gas flow discharged from the process chamber 104 at a more remote location to the fresh air required for the process chamber, in particular the inlet lock 118 and / or the outlet lock 120.

[0159] The remaining necessary temperature range is once again achieved with the aid of an electrically operated auxiliary heater 210 as a direct heater for the preheated fresh air flow conducted in the fresh air duct 122 .

[0160] Figure 6 A fifth specific embodiment of a treatment device 200 is shown which has been retrofitted using a retrofit kit 202 .

[0161] For example, similarly to the first embodiment, in the fifth embodiment the exhaust gas is conducted through the exhaust gas duct 124 to a purely electrically operated, flameless, regenerative thermal oxidizer 204 , wherein the oxidizer 204 replaces the thermal afterburner 142 , which is heated in particular by fossil fuels.

[0162] Likewise, an electrically operated auxiliary heating device 206 is preferably arranged downstream of the oxidation device 204 in order to provide additional thermal energy to the clean air drawn off from the oxidation device 204 or to further heat the clean air. However, the auxiliary heating device 206 is not necessarily required if the auxiliary heating device 210, which is designed to be correspondingly larger, compensates for the slightly preheated fresh air.

[0163] In an exemplary comparison with the first embodiment, however, the clean air duct 126 is now thermally decoupled from the circulating air module and accordingly conducts the heated clean air to the fresh air heat exchanger 144 without a stepwise heat transfer.

[0164] Instead of the original circulating air modules 110 , each with its own heat exchanger, electrically operated circulating air modules 214 are installed or equipped, which heat the corresponding partial circulating air flows 112 in a decentralized manner.

[0165] Therefore, in the fifth embodiment, no centralized and indirect heating of the circulating air module or unit is used, which is conducted via the oxidation device 204. However, during the purification of the exhaust gas in the oxidation device 204, a temperature range of fresh air heating in the fresh air heat exchanger 144 of the order of about 20 K is provided.

[0166] The heating of the partial circulating air flows 112 takes place in a decentralized manner by means of electrical direct heating via corresponding circulating air modules 214 , similar to a new system equipped with preferably purely electrical operation.

[0167] The recirculation air module 110 can advantageously be retrofitted by refitting only the internal heat exchanger and the air damper, closing the corresponding inlets and outlets, and using an electrical heating controller for the recirculation air module to form an electrically operated recirculation air module 214 .

[0168] therefore, Figure 6 The vertical displacement of the clean gas guide 126 represents only a schematic thermal decoupling and should not be synonymous with the laying of the corresponding actual pipeline.

[0169] In the case of the first, second, fourth and fifth embodiments, the oxidizing device 204 is preferably arranged or placed in a manner close to the dryer in order to clean the exhaust gas from the process chamber 104. However, here it is anticipated what might negatively affect the equilibrium of the process chamber 104 based on the short exhaust gas duct 124 with dynamic pressure changes between the process chamber 104 and the oxidizing device 204. The reason for this is that the pressure changes sharply This occurs within the oxidizer 204 due to a repeated reversal process of the flow on the hot bed of the oxidizer 204. This reversal is carried out, for example, every 3 to 7 minutes, depending on the solvent concentration and temperature, wherein the reversal is carried out via a disk valve and is necessary for stabilization of the temperature distribution on the hot bed of the oxidizer 204.

[0170] The described reversal within the oxidation device 204 generates undesirable pressure changes, which can lead to the process chamber 104 in the region of the inlet lock 118 and the outlet lock 120 to press the dryer atmosphere or the atmosphere of the process chamber 104 into the adjacent region or process chamber section 108, where it can condense. In order to prevent this, it is advantageous to

[0171] i) the volume flow to be purified, which is supplied to the oxidation device 204 via the exhaust gas duct 124 , is branched; or

[0172] ii) A buffer section between the processing chamber 104 and the oxidation device 204 is used to buffer the sudden pressure changes that are repeated over time.

[0173] For variant i), it is conceivable that the oxidation device 204 is configured such that the volume flow to be purified is divided into two or more flows with smaller volumes and guided through the oxidation device 204. Alternatively, two or more oxidation devices 204 are arranged in parallel with one another at the installation site of the oxidation device 204, so that the volume flow to be purified can be divided between the two or more oxidation devices.

[0174] Therefore, the one or more oxidation devices 204 are flowed through by a smaller volume, thereby reducing the intensity of the sudden pressure change caused by the switching and having less impact on the atmospheric balance of the processing chamber 104.

[0175] For variant ii), it is conceivable that the cross section or the diameter of the exhaust gas duct 124, which can be formed, for example, by a channel, extends from the process chamber 104 to the oxidation device 204. For example, at a volume flow of approximately 12000 Nm over a length of 6 m 3 / h, the diameter of the exhaust guide 124 can be increased from 0.6 m to 1.5 m.

[0176] Figure 6 The air attachment of the oxidation device 204 is schematically shown.

[0177] The exhaust gas to be purified from the process chamber 104 is supplied to the oxidation device 204 via the exhaust gas duct 124 , wherein, for example, the exhaust gas from the predryer 216 can be supplied to the exhaust gas duct 124 via the predryer exhaust gas duct 218 .

[0178] The combined exhaust gas from the treatment chamber 104 and the predryer 216 is conveyed by means of a first fan 220 in the direction of the oxidation device 204 , wherein the exhaust gas is initially conducted downstream of the first fan 220 into a buffer channel 222 .

[0179] The volume flow from the buffer channel 222 in the direction of the oxidation device is controlled and / or regulated via a valve device 224 .

[0180] A second ventilator (not shown) is associated with the oxidation device 204 and is preferably arranged upstream thereof. All internal pressure drops of the oxidation device 204 (eg 4000 Pa to 6000 Pa at 20° C.) are borne by the second ventilator.

[0181] In the clean gas guide 126, a third fan 226 is arranged downstream of the oxidation device and upstream of the auxiliary heating device 206. The third fan 226 overcomes all clean gas pressure drops downstream of the oxidation device 204, for example, 4000 Pa to 7000 Pa at 20°C.

[0182] For example, in the event of a malfunction of oxidation device 204 , a bypass line 228 branches off from exhaust gas line 124 downstream of buffer passage 222 and is supplied to clean gas line 126 , wherein the volume flow of bypass line 228 can be controlled and / or regulated via another valve mechanism 230 .

[0183] In order to coordinate the respective volume flows, valve device 224 of the exhaust gas duct and valve device 230 of the bypass duct 228 are connected to one another, preferably electrically.

[0184] Furthermore, purge air for controlling and / or regulating the temperature of the hot bed of oxidation device 204 can be supplied via purge air ducting 232 to a separate chimney 234 , wherein the volume flow can also be controlled and / or regulated via further valve means 236 .

[0185] The oxidation device 204 is also supplied with fresh air for the oxidation process, for example hall air or ambient air, via a fresh air line 238 , the volume flow of which can be controlled and / or regulated via a further valve arrangement 240 .

[0186] The valve device 236 of the purge air duct 232 and the valve device 240 of the fresh air duct 240 are likewise preferably connected to one another, in particular electrically connected, in order to coordinate the respective volume flows.

[0187] Description of Reference Numerals

[0188] 100 Basic structure of processing equipment

[0189] 102 Basic structure of dryer

[0190] 104 Processing Room

[0191] 106 Post-processing room

[0192] 108 Processing Chamber Section

[0193] 110 Circulation air module

[0194] 112 Local circulation air flow

[0195] 114 Local circulation air guide

[0196] 116 Conveying direction

[0197] 118 Entrance Gate

[0198] 120 Exit Gate

[0199] 122 Fresh air guide

[0200] 124 Exhaust guide

[0201] 126 Clean gas guide

[0202] 128 Post-processing chamber section

[0203] 130 Fresh air heat exchanger

[0204] 132 Exhaust Flow

[0205] 134 Fresh air flow supplied

[0206] 136 Preheated fresh air flow

[0207] 138 Circulating air flow

[0208] 140 Cooled exhaust gas flow

[0209] 142 Afterburning device

[0210] 144 Fresh air heat exchanger

[0211] 146 Fresh air supply

[0212] 148 Cooled clean gas flow

[0213] 150 Fresh air heat exchanger

[0214] 152 Fresh Air Flow

[0215] 154 Cooled clean gas flow

[0216] 156 Building Boundary

[0217] 200 Modified treatment equipment

[0218] 202 Modification Kit

[0219] 204 Regenerative Thermal Oxidizer

[0220] 206 Electrically operated auxiliary heating device

[0221] 208 Electrically operated auxiliary heating device

[0222] 210 Electrically operated auxiliary heating device

[0223] 212 Reconstruction of exhaust duct

[0224] 213 Hot oil circuit

[0225] 214 Electrically operated circulating air module

[0226] 216 Pre-dryer

[0227] 218 Pre-dryer exhaust guide

[0228] 220 First Ventilator

[0229] 222 Buffer Channel

[0230] 224 Valve mechanism

[0231] 226 Third Ventilator

[0232] 228 Bypass guide

[0233] 230 Valve mechanism

[0234] 232 Purge air guide

[0235] 234 Chimney

[0236] 236 Valve mechanism

[0237] 238 Fresh air guide

[0238] 240 Valve mechanism

Claims

1. A retrofit assembly (202) suitable for retrofitting a processing device, in particular an existing processing device, the processing device being used for processing a workpiece, in particular a dry vehicle body, wherein the retrofit assembly (202) comprises: - one or more auxiliary heating devices (206, 208, 210) suitable for warming the clean air guided in the clean air duct (126) and / or the fresh air guided in the fresh air duct (122); and a) a regenerative thermal oxidation device (204) replacing a thermal afterburner (142), in particular heated by fossil fuels; or b) a regenerative thermal oxidizer (204) replacing the fresh air heat exchanger (144) and a thermal afterburner (142) used as a retrofit for the fresh air heat exchanger (150), in particular heated by fossil fuels; or c) A regenerative thermal oxidizer (204) replacing a thermal afterburner (142), in particular heated by fossil fuels, and an electrically heated circulating air module (214) replacing a circulating air module (110) with a heat exchanger or a modified circulating air module (214) with an electrical heating regulator instead of a heat exchanger.

2. The retrofit assembly (202) according to claim 1, characterized in that The processing device to be converted has a conveying direction (116) and comprises: a treatment chamber (104) comprising a plurality of treatment chamber sections (108), each of which is associated with an individual circulating air module (110), each of which comprises a heat exchanger; - an exhaust gas guide (124) which guides exhaust gas out of the process chamber (104); a thermal afterburner (142), in particular heated by fossil fuels, for recovering, in particular purifying, exhaust gases, said thermal afterburner being provided for retrofitting or replacement; a clean gas duct (126) which conducts purified exhaust gas, in particular clean gas, wherein the clean gas duct (126) preferably extends at least approximately parallel to the conveying direction (116); and - A fresh air supply (122) which supplies fresh air to the processing chamber (104).

3. The retrofit assembly (202) according to claim 2, characterized in that: The process plant to be retrofitted further comprises a fresh air heat exchanger (144) designed to transfer the heat energy contained in the clean gas to fresh air (146) supplied to the process plant.

4. The retrofit assembly (202) according to any one of claims 1 to 3, characterized in that: One or more of the auxiliary heating devices (206, 208, 210) are purely electrically operated, hydrogen operated, or thermal oil operated auxiliary heating devices.

5. The retrofit assembly (202) according to any one of claims 1 to 4, characterized in that: The regenerative thermal oxidizer (204) is a purely electrically operated, in particular flameless, regenerative thermal oxidizer.

6. The retrofit assembly (202) according to any one of claims 1 to 5, characterized in that: One or more of the purely electrically operated auxiliary heating devices (206, 208, 210) and / or the purely electrically operated, in particular flameless, regenerative thermal oxidizer (204) can be connected to a central electrical connection point, in particular a power distribution station.

7. The retrofit assembly (202) according to any one of claims 1 to 6, characterized in that: The regenerative thermal oxidizer (204) includes a ventilator for conveying an air flow.

8. The retrofit assembly (202) according to any one of claims 1 to 7, characterized in that: In case c), the clean gas can be guided only to the fresh air heat exchanger (144) by means of the clean gas guide (126).

9. The retrofit assembly (202) according to any one of claims 1 to 7, characterized in that: In cases a) and c), a flow can flow through the clean gas guide (126) in the conveying direction (116).

10. The retrofit assembly (202) according to any one of claims 1 to 7, characterized in that: In case b), the clean gas duct (126) can flow counter to the conveying direction (116).

11. The retrofit assembly (202) according to any one of claims 1 to 10, characterized in that: The regenerative thermal oxidizer (204) is arranged at the end of the clean gas guide (126) with reference to the conveying direction (116).

12. The retrofit assembly (202) according to any one of claims 1 to 11, characterized in that: The fresh air heat exchanger (144) is configured as a thermal oil circuit (212) or a circuit complex system.

13. A method for retrofitting a processing device, in particular an existing processing device, for processing workpieces, in particular drying vehicle bodies, wherein the processing device to be retrofitted has a conveying direction (116), and wherein the processing device to be retrofitted comprises: a treatment chamber (104) comprising a plurality of treatment chamber sections (108), each of which is associated with an individual circulating air module (110), each of which comprises a heat exchanger; - an exhaust gas guide (124) which guides exhaust gas out of the process chamber (104); a thermal afterburner (142), in particular heated by fossil fuels, for recovering, in particular purifying, exhaust gases, said thermal afterburner being provided for retrofitting or replacement; a clean gas guide (126) which guides purified exhaust gas, in particular clean gas; a fresh air heat exchanger (144) which transfers the thermal energy contained in the clean gas to the fresh air (146) supplied to the processing equipment; and - a fresh air supply (122) which supplies fresh air to the processing chamber (104) via the fresh air heat exchanger (144); The method comprises the following steps: - installing one or more purely electrically operated auxiliary heating devices (206, 208, 210) in the clean air guide (126) and / or the fresh air supply (122); and a) replacing the thermal afterburner (142), which is heated in particular by fossil fuels, by a purely electrically operated, preferably flameless, regenerative thermal oxidizer (204); or b) replacing the fresh air heat exchanger (144) by a purely electrically operated, preferably flameless, regenerative thermal oxidizer (204) and retrofitting the thermal afterburner (142), which is heated, in particular, by fossil fuels, to serve as a fresh air heat exchanger (150); or c) replacing the thermal afterburner (142), in particular heated by fossil fuels, by a purely electrically operated, preferably flameless, regenerative thermal oxidizer (204), and replacing the circulating air module (110) with a heat exchanger by an electrically heated circulating air module (214), or replacing the heat exchanger of the circulating air module (110) by an electrically heated regulator.

14. The method according to claim 13, characterized in that One or more purely electrically, hydrogen- or thermal oil-operated auxiliary heating devices (206, 208, 210) and / or purely electrically operated, preferably flameless, regenerative thermal oxidizers are connected to a central electrical connection point, in particular a power distribution station.

15. The method according to claim 13 or 14, characterized in that In case b), the thermal afterburning device (142), in particular heated by fossil fuels, of the process plant to be retrofitted continues to be used as a fresh air heat exchanger (150).

16. The method according to claim 13 or 14, characterized in that In cases a) and c), the clean gas flows through the clean gas duct (126) in the conveying direction (116).

17. The method according to claim 13 or 14, characterized in that In case b), the clean gas flows through the clean gas duct (126) counter to the conveying direction (116).

18. The method according to any one of claims 13 to 17, characterized in that The exhaust gas is at least partially or at least nearly completely conducted through the purely electrically operated, preferably flameless, regenerative thermal oxidizer (204) and is at least temporarily heated there to a temperature at which substances contained in the air flow, in particular solvents, undergo a chemical conversion, and at least a portion of the heat temporarily contained in the exhaust gas is utilized as waste heat, so that the clean gas leaves the purely electrically operated, preferably flameless, regenerative thermal oxidizer (204) at a temperature between an input temperature and a temporary maximum temperature.

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