Workpiece processing equipment and its operation method

Abstract

A drying and / or hardening apparatus (10) for drying and / or hardening painted and / or coated and / or bonded workpieces, comprising: a processing chamber (18) for accommodating the workpiece (14) to be processed, the processing chamber being connected to processing air lines (40, 42, 44, 46, 50) for introducing processing air into and / or removing processing air from the processing chamber; a heating device (26-37) for heating the processing air to be introduced into the processing chamber (18); and a control mechanism (55) for controlling the amount of processing air introduced into and / or removed from the processing chamber, and for controlling the heating power of the heating device. The control mechanism (55) is designed such that it adjusts, controls, and / or regulates the amount of processing air and the heating power in relation to or with reference to each other.

Description

[0001] This application is a divisional application of Chinese invention patent application No. 201680060379.2, entitled "Workpiece Processing Equipment and Operating Method of Workpiece Processing Equipment", which entered the Chinese national phase on April 16, 2018.

[0002] This invention relates to a workpiece processing apparatus, particularly for drying and / or hardening painted and / or coated and / or bonded workpieces, and a method of operating such an apparatus, particularly for drying and / or hardening painted and / or bonded workpieces. The invention particularly relates to the field of continuous dryers, continuous hardening equipment, chamber dryers, and chamber hardening equipment, in which painted and / or bonded car bodies or body parts can be dried and / or hardened.

[0003] Such drying and / or hardening equipment is known, for example, from WO 2010 / 122121 A2. This typical drying and / or hardening equipment has a processing chamber with at least one area for receiving workpieces to be processed, the processing chamber being connected to a fresh air line for introducing fresh air into the processing chamber and an exhaust gas line for discharging exhaust gas from the processing chamber. To optimize the energy consumption of the drying and / or hardening equipment, fresh air and / or exhaust gas volume control is also specified for controlling the amount of fresh air to be introduced into the processing chamber and / or the amount of exhaust gas to be discharged from the processing chamber. Preferably, the fresh air and / or exhaust gas volume control is based on the number of workpieces currently being fed into the processing chamber.

[0004] The drying and / or hardening apparatus disclosed in WO 2010 / 122121 A2 also has a thermal afterburner (TNV) for thermal exhaust gas purification, to which exhaust gas from the treatment chamber is supplied and to which the purified air output is supplied to multiple recirculated air or fresh air recirculators to heat the recirculated air or fresh air to be introduced into the treatment chamber.

[0005] DE 10 2011 114 292 A1 describes a thermal afterburning device in which the combustion chamber temperature is not regulated to a fixed maximum value, but rather adjusted according to the carbon monoxide content in the clean air exhausted from the afterburning device. Due to this adjusted, lower average combustion chamber temperature, energy should be saved, and the materials used therein should be protected.

[0006] DE 10 2008 034 746 B4 discloses an apparatus for drying painted car bodies, which includes a thermal afterburner, wherein the concentration of harmful substances in the organic solvents in the dryer is continuously measured. When the concentration of harmful substances increases, the apparatus increases the fresh air input to the processing chamber and reduces the exhaust gas output from the processing chamber, while simultaneously maintaining a constant combustion chamber temperature by reducing the fuel input to the combustion chamber of the afterburner.

[0007] DE 10 2012 023 457 A1 describes methods and apparatus for temperature control, particularly for drying objects. All control and regulation processes of the dryer are coordinated by a control unit, which controls valves, the process air blower, the fresh air blower, and the burner. However, combined control of the process air volume and heating power is not specified here.

[0008] DE 20 2009 013 054 U1 discloses a system for controlling the interior temperature of a drying and / or painting workshop for repair painting of vehicles and vehicle parts. Temperature sensors detect the surface temperature of the object to be heated and / or dried non-contactly, and control and regulation devices control a blower and heating device based on the measured surface temperature of the object to be heated and / or dried. Combined control of the air volume and heating power is not specified herein.

[0009] The purpose of this invention is to provide an improved workpiece processing equipment and an improved operation method for the workpiece processing equipment with the lowest possible energy consumption.

[0010] This objective is achieved through the teachings of the independent claims. Advantageous designs of the invention are the subject of the dependent claims.

[0011] The workpiece processing apparatus according to the invention comprises: a processing chamber for accommodating a workpiece to be processed, connected to a processing air conduit for introducing processing air into and / or extracting processing air from the processing chamber; a heating device for heating the processing air to be introduced into the processing chamber; and a control mechanism for controlling the amount of processing air introduced into and / or extracted from the processing chamber, and for controlling the heating power of the heating device. The control mechanism is designed such that it adjusts, controls, and / or regulates the amount of processing air and the heating power in relation to and / or with reference to each other.

[0012] Energy-saving potential is also generated through a combination of control (i.e., adjustment, control, and / or regulation) of the amount of processed air introduced into and / or extracted from the processing chamber and the heating power of the heating device. Furthermore, the combination of these two controls creates synergistic effects that reduce the cost of measurement techniques used for equipment control, thereby lowering overall costs. This invention is particularly based on the concept that:

[0013] The goal is to enable workpiece processing equipment to operate as on demand and thus energy-efficiently as possible. "On demand" means, for example, adjusting the volumetric flow of processing air in the processing chamber and the heating power of the connected heating devices based on production data or parameters (e.g., the number of workpieces to be processed in the equipment). This improved regulation is feasible because, for example, reducing the number of workpieces in the processing chamber reduces the amount of hydrogen and / or carbon, particularly organic solvents and / or other hydrocarbons and / or other volatile, flammable, and easily oxidizable substances entering the equipment. To maintain the same, processable processing chamber atmosphere, the required amount of fresh air entering or leaving the processing chamber and the amount of exhaust gas are correspondingly reduced. Exhaust gas is typically expressed in units of mass / volume (e.g., g / m³). 3 The specific hazardous substance load described herein can be kept substantially constant corresponding to a reduced number of workpieces in the processing chamber. The reduction in exhaust gas volume flow—when the number of workpieces is small—leads to a longer residence time of the exhaust gas in the heating device, resulting in improved burnout (carbon monoxide content in the exhaust gas) and consequently, improved emission values. Due to this effect, it is feasible to reduce not only the fresh air volume flow and / or exhaust gas volume flow, but also the heating power of the heating device when the number of workpieces is small, while still maintaining the prescribed emission values. The reduction in the heating power of the heating device directly results in energy savings.

[0014] Reducing the heating power of the heating device can also extend the life of the workpiece processing equipment. Therefore, a decrease in the pure exhaust gas volume flow can, for example, result in very high preheating temperatures in the preheating and / or heating zones of the heating device due to structural and / or process reasons. In this case, the reduced heating power of the heating device can, particularly even under maximum preheating conditions, prevent potential damage, for example, due to thermal overload at the ends of the preheating zone of the heating device.

[0015] By integrating heating power control with air volume control, additional, often cumbersome measurement techniques used to detect the levels of harmful substances in exhaust gases or clean air discharged from the heating device can be optionally eliminated.

[0016] The term "processing air" should consequently encompass all types of airflow that can be introduced into and / or removed from a processing chamber. This includes, in particular, fresh air to be introduced into the processing chamber, exhaust gas to be removed from the processing chamber, and recirculated air to be removed from and reintroduced into the processing chamber. The term "air" should consequently encompass any gaseous fluid. This includes, in particular, (outdoor) air and gases that are, respectively, loaded with and unloaded with contaminants or hazardous substances.

[0017] The control mechanisms control the air volume and heating power in a relational or mutually referential manner. "Relational control" specifically refers to control in which there is a functional correlation between the two parameters, air volume and heating power. Preferably, for this functional correlation, there are fixed rules governing the entire range of parameter values. "Referential control" specifically refers to control in which different relationships, rules, or special provisions apply to different ranges of parameter values. Preferably, there is a tabular correlation between the values ​​of the two parameters, wherein this correlation is preferably determined empirically.

[0018] In a preferred design of the invention, the control mechanism can be designed to adapt the heating power of the heating device to the processing air volume or processing air volume control, or to adapt the processing air volume to the heating power or heating power control. This design particularly includes several different operating modes. Thus, the processing air volume control (master) can be at a higher level than the heating power control (slave), so that changes in the processing airflow automatically result in changes in the heating power of the heating device. Alternatively, the heating power control (master) can be at a higher level than the processing air volume control (slave), so that changes in the heating power automatically result in changes in the amount of processing air entering or exiting the processing chamber. It is also possible that the air volume control and heating power control are substantially at the same level, wherein the master / slave relationship is first determined based on, for example, production data or production parameters of the workpiece processing equipment. This design or operating mode of the control mechanism can advantageously help maintain the desired or prescribed emission limits of the equipment.

[0019] When heating power is adapted to processing air volume control or processing air volume is adapted to heating power control, the relationship between heating power and processing air volume is generally not proportional to each other under such integrated regulation. Alternatively, this relationship can be inversely proportional in some cases, such as when the number of workpieces decreases and it is necessary to increase the heating power within a certain range so as to provide sufficient pure gas enthalpy for process heating when the processing airflow decreases.

[0020] In a preferred embodiment of the invention, the processing air duct may have at least one fresh air duct for introducing fresh air into the processing chamber, at least one exhaust gas duct for removing exhaust gas from the processing chamber, and / or at least one recirculating air duct for removing exhaust gas from the processing chamber and reintroducing exhaust gas into the processing chamber. The control mechanism is thus preferably designed to control the amount of fresh air, exhaust gas, and / or recirculating air.

[0021] In another preferred embodiment of the invention, the heating device may have a combustion chamber. The control mechanism is then preferably designed to control the combustion chamber temperature. The combustion chamber temperature can be changed, for example, by altering the combustion gas supply.

[0022] In another preferred embodiment of the invention, the heating device may have a thermal afterburner (TNV) connected to an exhaust gas line that is connected to a treatment chamber and serves to introduce exhaust gas from the treatment chamber into the afterburner. The thermal afterburner is preferably designed to thermally oxidize, preferably regenerably or recyclably, combustible hazardous substances in the exhaust gas stream from the treatment chamber.

[0023] In another preferred design of the invention, the heating device may have at least one circulating air recirculator that carries the pure gas resulting from combustion and / or at least one fresh air recirculator.

[0024] The control mechanism is optimally designed so that (when the control of the processed air volume is determined as primary) it controls the processed air volume according to at least one parameter, said parameter being selected from:

[0025] - The number and / or weight and / or type and / or surface area of ​​the workpieces contained in the processing chamber;

[0026] - The number and / or weight and / or type and / or surface area of ​​the workpieces delivered to the processing chamber per unit time;

[0027] - The volumetric flow, mass flow, temperature, quality (e.g., uniformity of density distribution, volatility, etc.) and / or quantity of the processing medium and / or processing fluid (e.g., paint, coating powder, adhesive, etc.).

[0028] - The content of harmful substances and / or temperature and / or humidity of the treated air in the treatment chamber; and

[0029] - The content of harmful substances and / or temperature and / or humidity of the exhaust gas discharged from the treatment chamber.

[0030] The control mechanism is preferably designed such that (when heating power control is determined as the primary factor) it controls the heating power of the heating device according to at least one parameter, said parameter being selected from:

[0031] - The number and / or weight and / or type and / or surface area of ​​the workpieces contained in the processing chamber;

[0032] - The number and / or weight and / or type and / or surface area of ​​the workpieces delivered to the processing chamber per unit time;

[0033] - The content of harmful substances and / or temperature of the exhaust gas discharged from the treatment chamber;

[0034] - The content of harmful substances and / or temperature of the pure gas discharged from the heating device to the outside;

[0035] -The temperature difference between the circulating air exported from the processing chamber and the air introduced back into the processing chamber;

[0036] - The temperature difference between the exhaust gas supplied from the processing chamber to the combustion chamber of the heating device and the pure gas discharged from the combustion chamber;

[0037] - The position of the pure gas valve or dispensing valve determines how much or less the enthalpy of the pure gas is discharged into the circulating air, depending on the angle of the valve.

[0038] In a preferred design of the invention, the heating power can be adapted without detecting additional measurement parameters relating to the concentration of harmful substances in the processed air (clean air) introduced into the processing chamber and / or the processed air (exhaust gas) discharged from the processing chamber. This adaptation is preferably performed using a control algorithm derived empirically or theoretically. That is, to adapt the heating power, no additional measurement system is required; instead, the control device can utilize the data, parameters, and measurement parameters already present on it.

[0039] In the operation method of the workpiece processing equipment according to the invention, the workpiece to be processed is contained in a processing chamber, wherein the processing chamber is connected to a processing air pipeline for introducing processing air into and / or extracting processing air from the processing chamber; the processing air to be introduced into the processing chamber is heated by means of a heating device; the amount of processing air introduced into and / or extracted from the processing chamber and the heating power of the heating device are adjusted, controlled and / or regulated in relation to or with reference to each other.

[0040] This method can achieve the same advantages as the workpiece processing equipment described above in this invention. The above discussion of advantages, terminology definitions, and preferred designs applies accordingly.

[0041] This invention is preferably used in drying and / or hardening equipment for drying and / or hardening painted and / or coated and / or bonded workpieces. Workpieces, for example, are vehicle bodies or vehicle body sections.

[0042] The above and other advantages, features, and applications of the present invention will be better understood from the following description of various embodiments with the aid of the accompanying drawings. In these mostly illustrative drawings:

[0043] Figure 1 The structure of a workpiece processing apparatus according to a preferred embodiment of the present invention is shown;

[0044] Figure 2 Showing according to Figure 1 The structure of different modified workpiece processing equipment in the embodiments;

[0045] Figure 3 Showing according to Figure 1 The structure of other modified workpiece processing equipment in the embodiments;

[0046] Figure 4 Showing according to Figure 3 The structure of the workpiece processing equipment with additional modifications in the embodiment.

[0047] Figure 1 A workpiece processing apparatus 10 according to an embodiment of the present invention is shown, which is designed, for example, as a drying and / or hardening apparatus. The structure of the drying and / or hardening apparatus 10 is substantially consistent with that in WO 2010 / 122121 A2. Therefore, for the full details regarding the apparatus construction, the function of the components, and possible modifications, see WO 2010 / 122121 A2.

[0048] The drying and / or hardening equipment 10 may be part of a painting apparatus. For example, the painting apparatus may have one or more painting zones 12 in which the workpiece 14 is painted. The drying and / or hardening equipment 10 may be connected to these painting zones 12, particularly downstream along the conveying direction 16. A cooling zone (not shown) is typically also located downstream of the drying and / or hardening equipment 10, in which the workpiece 14 is cooled for other processing or working steps. The drying and / or hardening equipment 10 is particularly suitable for drying and / or hardening painted and / or bonded components, especially vehicle bodies, body sections, or other component groups (parts) of land, water, or air vehicles.

[0049] For example, Figure 1The workpiece 14 shown is designed as the body of a vehicle or aircraft to be painted. The workpiece 14 is fixed to a suitable carrier (slide) 15 that can move in the transport direction 16 to transport the workpiece 14 from the painting area 12 to and through the drying and / or hardening equipment 10. The transport of the workpiece 14 can be continuous or discontinuous. However, the workpiece processing equipment 10 according to the invention is also suitable for other applications.

[0050] The drying and / or hardening apparatus 10 has a processing chamber 18 with multiple zones 20-24. Here, the first zone 20 is designed as a gate zone in the form of an inlet gate. The second zone 21 is designed as a first heating zone, and the third zone 22 is designed as a second heating zone. Furthermore, the fourth zone 23 is designed as a holding zone, and the last zone 24 is designed as a gate zone in the form of an outlet gate. During operation of the drying and / or hardening apparatus 10, the workpiece 14 first enters the inlet gate 20, which seals the processing chamber 18 of the drying and / or hardening apparatus 10 relative to the outside. Under this sealing, the heated internal space of the processing chamber 18 is also thermally insulated from the outside. Gate zones 20 and 24 are preferably designed so that, particularly, processing air inside the processing chamber 18 does not escape from the processing chamber, or at least largely prevents escape.

[0051] The first heating zone 21 and the second heating zone 22 enable progressive (two-stage heating in this embodiment) heating of the workpiece 14. Under full load, one or more workpieces 14 can be heated in zones 21 and 22 respectively, wherein the workpiece 14 is heated in zone 21 and then fed into zone 22 for further heating. One or more workpieces 14 can be held in the holding zone 23 for a certain period of time to dry and harden the workpiece 14 (if necessary, by means of electromagnetic radiation). Thus—depending on low, medium, or high boiling point—solvents accumulate in the air of the processing chamber 18, primarily within the areas of the heating zones 21, 22, or the holding zone 23. These solvents are in the form of aliphatic and / or aromatic hydrocarbons, fluorocarbons, fluorochlorocarbons, esters, ketones, glycol ethers, ethanol, water, etc. However, the conditions under which the solvent escapes from the drying and / or hardening equipment 10 depend on the specific solvent or solvent composition. For low boiling points, the material escapes at low temperatures (<100°C); for medium boiling points, it escapes at medium temperatures (100°C to 150°C); and for high boiling points, it escapes at high temperatures (>150°C). A specific time can be defined for the drying and / or hardening process in holding zone 23, after which the workpiece 14 is output from the drying and / or hardening equipment 10 via gate zone 24. The bonded and / or painted workpiece 14 then dries and / or hardens.

[0052] During the operation of the drying and / or hardening equipment 10, it is necessary to replace the processing air in the processing chamber 18 to a certain extent. In this case, a certain amount of air can be released from the drying and / or hardening equipment 10 (exhaust gas) and replaced with fresh air. This replacement of processing air is necessary because the air in the processing chamber 18 is rich in solvents, which enter the interior space (useful space) of the processing chamber 18 of the drying and / or hardening equipment 10 from the paint film or adhesive during the drying and / or hardening process. This richness must be suppressed. In this way, the solvent-rich processing air can be replaced gradually, and in particular continuously, to ensure that the processing air can still absorb solvents. A certain threshold can be specified here, which, in order to maintain a normal drying and / or hardening process, especially with time and / or space constraints, must not be exceeded or may only be slightly exceeded. This air exchange is carried out in a targeted manner, in which, as much as possible, exchange is prevented via gate areas 20, 24, because otherwise hot air would be allowed to escape from the processing chamber 18 to the outside in an undesirable manner, or—while fresh air is drawn into the processing chamber 18 primarily via gate areas 20, 24—to allow excessive amounts of cold outside air to enter the processing chamber 18.

[0053] The drying and / or hardening equipment 10 also has a heating device 26-37. The heating device has a thermal afterburner (TNV) 26, at least one, preferably multiple (here, three) circulating air recirculators 28, 30, 32 and usually one (in rare cases, none) fresh air recirculator 34.

[0054] The thermal afterburning mechanism 26 is preferably designed to thermally oxidize combustible hazardous substances in the exhaust gas from the treatment chamber 18 in a regenerative or recyclable manner, and preferably includes a gas burner 36. The hot, clean air generated by the gas burner 36 in the combustion chamber 37 is guided through recoverers 28, 30, 32, and 34, and then discharged into the atmosphere, as indicated by arrow 38. That is, the hot exhaust gas (clean air) of the TNV 26 is used as an energy source in the recoverers 28, 30, 32, and 34 to heat the circulating air or fresh air. Throttling valves are provided in the recoverers 28, 30, 32, and 34 respectively, so that a portion of the heat energy generated by the gas burner 36 is utilized in the respective recoverer, and the remainder is transferred to the next recoverer.

[0055] The recirculating air recirculators 28, 30, 32, and 34 also have heat exchangers 29, 31, 33, and 35, respectively. The heat exchanger 29 of the first circulating air recirculator 28 is equipped with a suction side and an outlet side of the circulating air duct 40 connected to the first heating zone 21. Here, the heat exchanger 29 is installed on the circulating air duct 40 together with a ventilator. Depending on the position of the throttle valve of the first circulating air recirculator 28, the circulating air flowing through the heat exchanger 29 and fed back to the first heating zone 21 is heated to varying degrees to ensure that a certain temperature of the processed air is reached and maintained within the first heating zone 21 of the processing chamber 18 during the operation of the equipment 10. Similarly, the second heating zone 22 of the processing chamber 18 is connected to a second circulating air recirculator 30 via a circulating air duct 42, which has a heat exchanger 31 disposed on the circulating air duct 42. The holding zone 23 of the processing chamber 18 is connected to a third circulating air recirculator 32 via a circulating air duct 44, which has a heat exchanger 33 disposed on the circulating air duct 44. This allows the processed air to be heated in zones 21, 22, and 23 and its temperature maintained at a desired level.

[0056] In addition, at least one exhaust gas duct 46 was installed. According to Figure 1 The suction side of the exhaust gas duct 46 is located in the holding area 23 of the processing chamber 18, while the outlet side of the exhaust gas duct 46 leads into the combustion chamber 37 of the TNV 26. The oxygen required for combustion of the combustion gases is thus obtained from the exhaust gas flowing through the exhaust gas duct 46 from the holding area 23, wherein the exhaust gas is heated. Here, the exhaust gas from the holding area 23 undergoes thermal purification, thereby discharging clean air into the atmosphere in the direction of arrow 38. A heat exchanger 27 is provided on the exhaust gas duct 46, so that the exhaust gas flowing into the combustion chamber 37 on the outlet side can be preheated. A throttle valve 47 and a ventilator 48 are also provided on the exhaust gas duct 46, the ventilator being designed as a specially (frequency) controlled ventilator.

[0057] Furthermore, the drying and / or hardening equipment 10 has a fresh air duct 50 with a fresh air inlet 52 through which fresh air can be drawn in. From the fresh air inlet 52, the fresh air is guided through the fresh air duct 50 and first through the fresh air recirculator 34, through which a heat exchanger 35 is disposed on the fresh air duct 50. In this embodiment, the fresh air duct 50 has a first outlet at a gate zone 20 in the processing chamber 18 and a second outlet at a gate zone 24. Here, throttle valves are disposed before these outlets to regulate the proportion of fresh air input through the fresh air duct 50 directed to these outlets respectively. Optionally, adjustable grids or nozzles are disposed at each or all of the outlets to allow for regulation of the volumetric flow. A special (frequency)-controlled ventilator 53 is also disposed on the fresh air duct 50. In this embodiment, the ventilator 53 is disposed on the fresh air duct 50 before the heat exchanger 35 of the recirculator 34.

[0058] like Figure 1 As shown, the drying and / or hardening equipment 10 also includes a control mechanism 55. This control mechanism 55 is specially designed to control, on the one hand, the amount of fresh air introduced into the gate areas 20, 24 of the processing chamber 18 via the fresh air duct 50, and / or the amount of waste gas discharged from the holding area 23 of the processing chamber 18 via the waste gas duct 46, and on the other hand, the heating power of the TNV 26. Furthermore, the control mechanism 55 can also control the amount of circulating air guided via the circulating air ducts 40, 42, 44.

[0059] For this purpose, control mechanism 55 is connected to the control element (e.g., actuator) 56 of the ventilator 48 on the exhaust gas line 46, the control element (e.g., actuator) 57 of the ventilator 53 on the fresh air line 50, and the control element of the gas burner 36 in the combustion chamber 37 of the TNV 26. Alternatively or additionally, control mechanism 55 may also be connected to the regulating element of a throttling element or throttling valve on the exhaust gas line 46 or the fresh air line 50, and / or to a throttling valve / pure gas valve for controlling the enthalpy of pure gas for the recirculating air recirculators 28, 30, 32.

[0060] Different from or supplemented by Figure 1The exhaust gas duct 46 shown may also have its suction side mechanism located in one or more heating zones 21, 22, or in the transition between two successive zones 21, 22, 23 and / or 24. Preferably, the suction side of the exhaust gas duct 46 is located in the zone of maximum concentration of combustible hazardous substances in the processed air within the processing chamber 18, or in a zone of the processing chamber 18 following the section or zone of maximum increase in the concentration of combustible hazardous substances in the processed air. Particularly preferably, the exhaust gas side of the exhaust gas duct 46 is arranged here after the heating zone 21. If more than one exhaust gas duct 46 is provided, a controllable and / or adjustable throttle valve or shut-off valve 47 may be provided on at least one exhaust gas duct 46, and / or a separate controllable and / or adjustable ventilator 48 may be provided to control the volumetric flow through the respective exhaust gas duct 46, which is advantageously connected to the control mechanism 55.

[0061] To control the amount of fresh air introduced into zones 20 and 24 and the amount of exhaust gas discharged from zone 23, control mechanism 55 can consider one or more parameters. These parameters are advantageously stored in control software, whereby they can be changed according to the operation of device 10. Since the dissolved air dosage introduced into processing chamber 18 changes under different operating conditions, such as during paused operation, partial load operation, or full load operation, the number of workpieces 14 contained in processing chamber 18 can be used as a parameter. Typically, the dissolved air dosage introduced into processing chamber 18 changes directly according to the number of workpieces 14, thus the amount of fresh air and exhaust gas can be changed proportionally to the number of workpieces 14. Figure 1 As shown, the control mechanism 55 is connected to the workpiece detection mechanism 60, which can detect the number of workpieces 14 delivered to the processing chamber 18 of the drying and / or hardening equipment 10.

[0062] In this embodiment, a workpiece detection mechanism 60 is provided, which is disposed along the conveying direction 16 between the gate area 20 and the coating area 12 of the processing chamber 18 of the drying and / or hardening equipment 10. Alternatively or additionally, at least one, preferably multiple, workpiece detection mechanisms may be provided after the processing chamber 18. In another embodiment, such a separate workpiece detection mechanism may be omitted if an indicator of the number of workpieces is otherwise defined by equipment control. As the workpiece detection mechanism 60, a sensor or transmitting / receiving unit is preferably considered, which operates based on electromagnetic waves, inductance, and / or gravity measurements. The workpiece detection mechanism 60 may, for example, be designed as a sensor that causes at least one clock signal or another measurement parameter relating to and / or characterizing the carrier 15 or workpiece 14 to be transmitted or transmitted to the control mechanism 55 when the carrier 15 or workpiece 14 passes by. Thus, the control mechanism 55 can determine the current load level of the drying and / or hardening equipment 10 from the obtained clock signal. Alternatively or supplementarily, the position of the workpiece in the dryer can be determined by a clock signal and / or by another measuring parameter detected by the workpiece inspection mechanism 60 that relates to and / or characterizes the carrier 15 or the workpiece 14. Furthermore, alternatively or supplementarily, the amount of fresh air and / or exhaust gas can be—if necessary or advantageous—correlated with the stated position of the carrier 15 or the workpiece 14, with the processing procedure (e.g., position in the heating or holding zone), and / or with the measuring parameters, particularly for control and / or regulation. However, the workpiece inspection mechanism 60 can also be designed as a reader, RFID reader, barcode reader, etc. In such a design, the workpiece inspection mechanism 60 can, for example, detect the workpiece number of the workpiece 14, or detect information associated with the workpiece 14.

[0063] Alternatively or additionally, it is also feasible to consider other process parameters of equipment 10, such as the size of workpiece 14, the material of workpiece 14, etc. Other process parameters that can be considered alternatively or additionally are volumetric flow rate, mass flow rate, temperature, quality (e.g., uniformity of density distribution, humidity, etc.) and / or the amount of processing media and / or processing fluids (e.g., paint, coating powder, adhesive, etc.). The control mechanism 55 can obtain this information, for example, by controlling the equipment above the painting equipment.

[0064] In this way, excessive accumulation of solvent, which enters the processing chamber 18 of the drying and / or hardening equipment 10 from the paint film, adhesive, etc., during the drying and / or hardening process, can be suppressed. For this purpose, a sufficient amount of fresh air can be continuously introduced into the processing chamber 18 while the solvent-containing waste gas is discharged from the processing chamber 18. The amount of waste gas obtained via the waste gas duct 46 can thus be replaced by a corresponding amount of fresh air. The amount of fresh air introduced and the amount of waste gas discharged are selected here to prevent and / or reduce the formation of condensate in the areas of the gate zones 20, 24. Furthermore, the amounts of fresh air and waste gas are optimally selected, i.e., as small as possible, to save energy. In particular, energy is required in the fresh air recovery unit 34 to heat the fresh air input via the fresh air duct 50, and its consumption can thus be optimized. Furthermore, for the discharged waste gas, thermal waste gas purification is preferably performed in the TNV 26.

[0065] Further energy savings are achieved by adapting the heating power of the heating devices 26-37, particularly the burner power of TNV 26, to fresh air volume control and / or exhaust gas volume control using the control mechanism 55. This adaptation of heating power can optionally be performed without additional measuring systems (e.g., for detecting the concentration of harmful substances in clean air, such as downstream of TNV 26 in clean air or upstream of TNV 26 in exhaust gas), based on the production date and production parameters provided by the device 10 and already used by the control mechanism 55 for fresh air volume control and / or exhaust gas volume control.

[0066] The control mechanism 55 enables on-demand, and thus energy-efficient, operation of the drying and / or hardening equipment 10. The improved equipment control proposed herein is feasible because, for example, a reduction in the number of workpieces 14 in the processing chamber 18 reduces the amount of water and carbon, particularly solvents and / or hydrocarbons, entering the equipment 10. To maintain the same, processable processing chamber atmosphere, the required volumetric flow rate of fresh air introduced into the processing chamber 18 and exhaust gas removed from the processing chamber 18 is correspondingly reduced. This is typically expressed in units of mass / volume (e.g., g / m³). 3 The hazardous substance load per unit of exhaust gas described herein remains essentially constant due to the small number of components in processing chamber 18. As the exhaust gas volume flow decreases, the residence time of the exhaust gas in TNV 26 increases, resulting in improved burnout and consequently, improved emissions of clean air. Therefore, it is feasible to reduce not only the fresh air volume flow and / or the exhaust gas volume flow, but also the burner power of TNV 26, while maintaining the specified emissions values, even when the number of components is small.

[0067] The reduction in combustion chamber temperature in the TNV 26 is technically beneficial, and sometimes necessary, because a simple reduction in exhaust gas volume flow can result in very high preheating temperatures in the heating zone of the TNV 26 due to its construction. As a possible consequence, for example, thermal overload may occur at the end of the preheating zone of the TNV 26, potentially causing equipment damage. Therefore, it is advantageous that the controlled air volume and combustion chamber temperature regulation together lead to overall control.

[0068] As described above, this "mutually resulting" can be viewed as follows: fresh air volume control and / or exhaust gas volume control are more advanced than combustion chamber temperature regulation. An increase or decrease in the exhaust gas volume flow through exhaust duct 46 will automatically lead to an increase or decrease in combustion chamber temperature. The control algorithm upon which this is based can, for example, be adapted to the current equipment 10 within the TNV 26 emission regulation range via benchmark measurements.

[0069] Here, the control mechanism 55 can preferably control the amount of fresh air entering or exiting the processing chamber 18 of the drying and / or hardening equipment 10 according to one or more of the following process parameters:

[0070] - The number and / or weight and / or type and / or surface area of ​​the workpieces 14 contained in the processing chamber 18;

[0071] - The number and / or weight and / or type and / or surface area size of the workpieces 14 delivered to the processing chamber 18 per unit time.

[0072] Fresh air volume control and / or exhaust gas volume control can be based on other possible process parameters, which are:

[0073] - Volumetric flow, mass flow, temperature, quality and / or quantity of the processing medium and / or processing fluid;

[0074] - The content of harmful substances and / or temperature and / or humidity of the treated air in the treatment chamber 18;

[0075] - The content of harmful substances and / or temperature and / or humidity of the exhaust gas discharged from the treatment chamber 18.

[0076] Alternatively, an adjustment architecture can be specified by the control mechanism 55, in which the combustion chamber temperature of the TNV 26 can be adjusted (primary) according to certain process parameters of the device 10, and automatically adapted to the fresh air volume flow and / or exhaust gas volume flow (secondary).

[0077] Here, the control mechanism 55 also preferably controls the combustion chamber temperature of the TNV26 according to one or more of the following process parameters of the device 10:

[0078] - The number and / or weight and / or type and / or surface area of ​​the workpieces 14 contained in the processing chamber 18;

[0079] - The number and / or weight and / or type and / or surface area size of the workpieces 14 delivered to the processing chamber 18 per unit time.

[0080] The combustion chamber temperature can be adjusted based on other possible process parameters, which are:

[0081] - The content of harmful substances and / or temperature of the exhaust gas discharged from the treatment chamber 18;

[0082] - The content of harmful substances and / or temperature of the pure gas discharged from the heating device 26-37 to the outside;

[0083] -The temperature difference between the circulating air (zones 21, 22, 23) that is discharged from the processing chamber and then introduced back into the processing chamber;

[0084] - The temperature difference between the exhaust gas supplied from the processing chamber 18 to the combustion chamber 37 of the TNV 26 and the pure gas discharged from the combustion chamber 37;

[0085] - The position of the pure gas valve or dispensing valve determines how much or less the enthalpy of the pure gas is discharged into the circulating air, depending on the angle of the valve.

[0086] Finally, it is also possible to consider treating air volume control and combustion chamber temperature control at the same level in principle. That is, the corresponding master / slave relationship between these two controls performed by control mechanism 55 is determined first during the operation of drying and / or hardening equipment 10 based on the current production date or production parameters.

[0087] Now refer to Figure 2 Let me introduce Figure 1 Various modifications of the drying and / or hardening equipment 10 may be specified individually or in any combination.

[0088] As described above, the control mechanism 55 may also selectively use at least one state parameter (e.g., humidity, temperature, hazardous substance content) of the processed air in the processing chamber 18 as other process parameters. Figure 2 As shown, the corresponding processing air sensor 62 can therefore optionally be placed in / on the processing chamber 18. Figure 2When the processed air sensor 62 is located in / at the gate area 20, one or more processed air sensors may also be alternatively or additionally located in / at one or more other areas 21-24 of the processing chamber 18. This or these processed air sensors 62 may be designed, for example, as a humidity meter or hygrometer to determine humidity, as a thermometer, infrared sensor, thermoelectric component, etc. to determine temperature, and / or as a flame ionization detector (FID), catalytic combustion sensor, electrochemical cell, optical gas sensor, DC concentration cell, etc. to determine the content of hazardous substances.

[0089] As described above, the control mechanism 55 can also selectively use the state parameters (e.g., humidity, content of harmful substances) of the exhaust gas discharged from the treatment chamber 18 via the exhaust gas duct 46 as other process parameters. Figure 2 As shown, at least one corresponding exhaust gas sensor 64 can therefore optionally be placed in / on the exhaust gas line 46. Alternatively or supplementarily, the exhaust gas sensor 64 can also be arranged or placed in the processing chamber 18, preferably in an area from which it can be drawn or drawn by means of a suction line, particularly in the area on the suction side of the suction line 46. The exhaust gas sensor 46 is specifically designated, arranged, and / or constructed to at least determine quality, characteristic, and / or state parameters, particularly the humidity, temperature, and / or content of harmful substances in the exhaust gas or the processing air to be drawn. This or these exhaust gas sensors 64 can be designed, for example, as a humidity meter or hygrometer to determine humidity, as a thermometer, infrared sensor, thermoelectric component, etc. to determine temperature, and / or as a flame ionization detector (FID), catalytic combustion sensor, electrochemical cell, optical gas sensor, DC concentration cell, etc. to determine the content of harmful substances.

[0090] As mentioned above, the control mechanism 55 can also selectively use the state parameters (e.g., humidity, temperature, harmful substance content) of the pure air 38 output from the heating devices 26-37 as other process parameters. Figure 2 As shown, the corresponding clean air sensor 66 can therefore optionally be positioned downstream of the heating device. Alternatively or additionally, the clean air sensor can also be positioned between the TNV 26 and the first circulating air recirculator 28. The clean air sensor 66 can be designed, for example, as a humidity meter or hygrometer for determining humidity, as a thermometer, infrared sensor, thermoelectric component, etc. for determining temperature, and / or as a flame ionization detector (FID), catalytic combustion sensor, electrochemical cell, optical gas sensor, DC concentration cell, etc. for determining the content of harmful substances.

[0091] like Figure 2 As shown, various other exhaust gas pipelines 68, 70, 72, and 74 can also be installed.

[0092] Similar to exhaust gas line 46, the suction side of other exhaust gas line 68 is located in the holding area 23 of the processing chamber 18. This other exhaust gas line 68 is guided together with the fresh air line 50 so that fresh air from the fresh air inlet 52 mixes with the exhaust gas from the other exhaust gas line 68. This mixture of fresh air and exhaust gas is delivered to the gate areas 20, 24 of the processing chamber 18 via the fresh air line 50. Preferably, the other exhaust gas line 68 is equipped with an adjustable flow rate, particularly a frequency-controlled ventilator, and a throttling valve. In this design, the control mechanism 55, in addition to considering energy saving and condensation prevention, preferably also considers a third criterion: limiting the solvent concentration to below 25% of the lower decomposition limit (UEG). To meet these criteria, a certain amount of exhaust gas should be discharged from the holding area 23. The exhaust gas removed from the processing chamber 18 via exhaust gas line 46 undergoes thermal purification in the combustion chamber 37 of the TNV 26. A portion of the exhaust gas, led from the holding zone 23 via other exhaust gas lines 68 and introduced into the gate zones 20, 24 along with fresh air, serves as circulating air for the entire drying and / or hardening equipment 10. This solvent-rich processing air can be distributed along the processing chamber 18. This reduces the high concentration of solvent in the processing air in the holding zone 23, where thermal energy is retained, further reducing energy requirements. Furthermore, a portion of the exhaust gas volume guided via other exhaust gas lines 68 replaces a portion of the introduced fresh air volume. In this case, the gas mixture of exhaust gas and fresh air entering the gate zones 20, 24 is heated, and the solvent content is relatively low. If this mixture comes into contact with the gate circulating air in the gate zones 20, 24, condensation in these zones can be suppressed. Alternatively or additionally, the exhaust gas used as recirculated air may also be obtained from another area of ​​the treatment chamber 18, such as from the first heating zone 21 and / or the second heating zone 22.

[0093] Exhaust gas used as recirculating air can be discharged from the holding area 23 of the processing chamber 18 via other exhaust gas lines 70, 72, and preferably delivered directly, i.e., without mixing with fresh air, to the gate areas 20, 24. The two other exhaust gas lines 70, 72 may selectively have separate suction positions in the holding area 23, or have a common suction position.

[0094] Exhaust gas used as circulating air can be discharged from the first heating zone 21 of the processing chamber 18 via other exhaust gas pipes 74 and delivered to the gate zone 20. In this way, a certain amount of exhaust gas can be introduced from the first heating zone 21 into the gate zone 20.

[0095] Although not specified, ventilators, throttling devices or valves, filters and / or exhaust gas sensors 64 may also be installed on other exhaust gas ducts 68, 70, 72, 74.

[0096] Reference Figure 3 , will introduce Figure 1 Various other modifications of the drying and / or hardening equipment 10. These other modifications may be specified independently, or in any combination, and / or with... Figure 2 One or more combinations thereof are specified in any combination.

[0097] like Figure 3 As shown, an intermediate gate 25 may be optionally provided between the first heating zone 21 and the second heating zone 22. A branch pipe 51 branches off from the fresh air pipe 50, through which a curtain of fresh air flow can be generated in the intermediate gate 25 by means of a nozzle.

[0098] Alternatively, fresh air can be directed to one or more recirculating air ducts 40, 42, 44. For this purpose, another fresh air duct 76 is provided, for example, branching upstream and / or downstream of the heat exchanger 35 of the fresh air recirculator 34, and for example, downstream of the heat exchangers 29, 31, 33 of the respective recirculating air recirculators 28, 30, 32, into the respective recirculating air ducts 40, 42, 44.

[0099] Other variations of the drying and / or hardening equipment 10 have a flow measurement mechanism 78 on another fresh air line 76, and / or a flow measurement mechanism 79 on the fresh air line 50.

[0100] See Figure 4 , will introduce Figure 1 Various additional modifications to the drying and / or hardening equipment 10, wherein they are shown herein according to Figure 3 These are supplementary modifications to the design. However, these additional modifications can also be specified independently, or in any combination, and / or with... Figure 2 One or more combinations thereof are specified in any combination.

[0101] For example, supplemented by Figure 3At least one additional exhaust gas duct 46 is provided, with its suction side positioned at the intermediate gate 25. Here, a throttle valve 47, a ventilator 48, and / or an exhaust gas sensor 64 can be provided or arranged on at least one exhaust gas duct 46, advantageously characterizing, determining, and / or identifying the flow rate through the respective exhaust gas duct 46. The throttle valve 47 and / or ventilator 48 are advantageously connected to the output duct of the control mechanism 55, and the exhaust gas sensor 64 is connected, in particular, to the input duct. Regarding the type and function of the exhaust gas sensor 64, see here for reference to... Figure 2 Description of the embodiments.

[0102] Optionally, it may also be specified that a clean air sensor 66 be installed on the clean air line or pipeline, for example, one that is already in use. Figure 2 These designs have been described in the design section; please refer to them here.

[0103] If already Figure 1 As described in the instructions, in heating devices 26-37, especially TNV 26, according to Figure 4 A regulating valve is shown for controlling the delivery of fuel or fuel-air mixture, and it is connected to the output line of control device 55. In addition to the regulating valve, heating devices 26-37, particularly TNV 26, can optionally be connected to the output of control device 55 for an ignition mechanism (not shown), and / or to the input of the control device for a combustion chamber monitoring sensor (also not shown), thereby advantageously introducing control over the ignition process, and / or enabling monitoring of the ignition and / or combustion process.

[0104] According to Figure 4Another modification further specifies that, supplementing or replacing the data of the workpiece inspection mechanism 60, processing and / or production data 12A from the preceding painting and / or coating and / or bonding processes, particularly from the painting, coating and / or bonding equipment, preferably from the painting chamber 12, can be transmitted to and / or retrieved by the control mechanism 55. For the workpiece processing equipment 10 according to the invention or the method according to the invention, processing and / or production data 12A regarding the working materials used (e.g., paint, coating materials, adhesives and / or additives, particularly in terms of composition, physical / chemical properties), order characteristics (e.g., layer thickness), and / or workpiece characteristics (e.g., mass, volume, surface, shape) are particularly important. This data can, for example, be transmitted to, provided to, and / or retrieved by the control mechanism 55 via a data bus from the processing computer of the preceding painting and / or coating and / or bonding processes. Alternatively or supplementarily, the processing and / or production data 12A may be transmitted to the workpiece 14 or to the carrier 15 or both, and preferably read by means of the workpiece inspection mechanism 60 or another reading unit, and transmitted to the control mechanism 55 for processing. This allows certain parameter values, parameter intervals, and / or parameter groups to be encoded into a preferred machine-readable code (e.g., barcode, QR code), wherein the control mechanism 55 advantageously has a corresponding decoding unit to analyze the transmitted processing and / or production data 12A, thus encoded, for processing. Alternatively or supplementarily, the processing and / or production data 12A may be stored, encoded or decoded, and retrievably in storage components on the workpiece 14 and / or carrier 15, wherein advantageously, the workpiece inspection mechanism 60 or another reading unit of the workpiece processing equipment 10 reads the processing and / or production data 12A required for control. Additionally, a write unit may be provided, for example, in or after the exit gate area 24, to store the processing and / or production data 10A of the workpiece processing in the workpiece processing equipment 10 in the storage components of the workpiece 14 and / or carrier 15. Alternatively or additionally, the control unit 55 may also transmit the processing and / or production data 10A to the process control computer.

Claims

1. A workpiece processing device (10), comprising: A processing chamber (18) for accommodating the workpiece (14) to be processed, wherein, The processing chamber (18) is connected to processing air conduits (40, 42, 44, 46, 50), which are used to introduce processing air into the processing chamber and / or to exhaust processing air from the processing chamber. The processing air ducts (40, 42, 44, 46, 50) include a fresh air duct (50) for introducing fresh air into the processing chamber and at least one recirculating air duct (40, 42, 44) for discharging exhaust gas from the processing chamber and re-introducing exhaust gas into the processing chamber. Heating devices (26-37) for heating the processing air to be introduced into the processing chamber (18); and A control mechanism (55) is used to control the amount of processing air introduced into and / or discharged from the processing chamber, and to control the heating power of the heating device. The feature is that the workpiece processing equipment is further provided with another fresh air pipeline (76) for delivering fresh air to one or more of the at least one circulating air pipeline (40, 42, 44). The control mechanism (55) is designed to adjust, control and / or regulate the amount of processed air and heating power in relation to or by reference to each other.

2. The workpiece processing equipment as described in claim 1, wherein, The control mechanism (55) is designed to adapt the heating power of the heating device to the processing air volume or the processing air volume control, or to adapt the processing air volume to the heating power or the heating power control, so as to integrate the heating power control with the processing air volume control.

3. The workpiece processing equipment as described in claim 2, wherein, The control mechanism (55) is designed such that the processing air volume control is at a higher level than the heating power control level, so that a change in the processing air volume will automatically result in a change in the heating power of the heating device, or the heating power control is at a higher level than the processing air volume control level, so that a change in the heating power will automatically result in a change in the amount of processing air entering or leaving the processing chamber.

4. The workpiece processing equipment as described in claim 1, wherein, The processed air ducts (40, 42, 44, 46, 50) have an exhaust gas duct (46) for discharging exhaust gas from the processed chamber; and The control mechanism (55) is designed to control the amount of fresh air, exhaust gas and / or recirculated air.

5. The workpiece processing equipment as described in claim 1, wherein, The heating device (26-37) has a combustion chamber (37); and The control mechanism (55) is designed to control the combustion chamber temperature of the combustion chamber (37).

6. The workpiece processing equipment as described in claim 1, wherein, The heating device (26-37) has a thermal afterburning mechanism (26) connected to an exhaust gas pipeline (46) connected to the processing chamber (18) and used to transport exhaust gas from the processing chamber to the afterburning mechanism (26).

7. The workpiece processing equipment as described in claim 1, wherein, The heating device (26-37) has a recirculating air recirculator (28, 30, 32) and / or a fresh air recirculator (34); and The purified gas resulting from combustion is delivered to the circulating air recirculator (28, 30, 32) and / or the fresh air recirculator (34).

8. The workpiece processing equipment as described in claim 7, wherein, The other fresh air duct (76) branches upstream and / or downstream of the heat exchanger (35) of the fresh air recirculator (34) and enters into the corresponding circulating air duct (40, 42, 44) downstream of the heat exchanger (29, 31, 33) of the corresponding circulating air recirculator (28, 30, 32).

9. The workpiece processing equipment according to any one of claims 1 to 8, wherein, The control mechanism (55) is designed to control the amount of processed air according to at least one parameter, the parameter being selected from: - The number and / or weight and / or type and / or surface area of ​​the workpieces (14) contained in the processing chamber (18); - The number and / or weight and / or type and / or surface area of ​​the workpieces (14) delivered to the processing chamber (18) per unit time; - Volumetric flow rate, mass flow rate, temperature and / or quality of the processing medium and / or processing fluid; - The content of harmful substances and / or temperature and / or humidity of the processed air in the processing chamber (18); - The content of harmful substances and / or temperature and / or humidity of the exhaust gas discharged from the treatment chamber (18).

10. The workpiece processing equipment according to any one of claims 1 to 8, wherein, The control mechanism (55) is designed to control the heating power of the heating device according to at least one parameter, the parameter being selected from: - The number and / or weight and / or type and / or surface area of ​​the workpieces (14) contained in the processing chamber (18); - The number and / or weight and / or type and / or surface area of ​​the workpieces (14) delivered to the processing chamber (18) per unit time; - The content of harmful substances and / or temperature of the exhaust gas discharged from the processing chamber (18); - The content of harmful substances and / or temperature of the pure gas discharged from the heating device (26-37) to the outside; - The temperature difference between the circulating air exported from the processing chamber and the air introduced back into the processing chamber; - The temperature difference between the exhaust gas supplied from the processing chamber (18) to the combustion chamber (37) of the heating device and the pure gas discharged from the combustion chamber; - Position of the pure gas valve or dispensing valve.

11. The workpiece processing equipment as described in claim 1, wherein, The workpiece processing equipment (10) is used for drying and / or hardening painted and / or coated and / or bonded workpieces.

12. An operating method for a workpiece processing equipment (10), wherein, The workpiece (14) to be processed is housed in a processing chamber (18), wherein the processing chamber (18) is connected to processing air lines (40, 42, 44, 46, 50) for introducing processing air into and / or removing processing air from the processing chamber. The processing air ducts (40, 42, 44, 46, 50) include a fresh air duct (50) for introducing fresh air into the processing chamber and at least one recirculating air duct (40, 42, 44) for removing exhaust gas from the processing chamber and re-introducing exhaust gas into the processing chamber; and The processing air to be introduced into the processing chamber (18) is heated by means of heating devices (26-37); The feature is that fresh air is also delivered via another fresh air duct (76) to one or more of the at least one recirculating air ducts (40, 42, 44); and The amount of processing air introduced into and / or exported from the processing chamber and the heating power of the heating device are adjusted, controlled and / or regulated in relation to or by reference to each other.

13. The method of claim 12, wherein, The heating power of the heating device is adapted to the processing air volume or processing air volume control, or the processing air volume is adapted to the heating power or heating power control, so as to integrate the heating power control with the processing air volume control.

14. The method of claim 13, wherein, The processing air volume control is at a higher level than the heating power control, so that a change in the processing air volume will automatically lead to a change in the heating power of the heating device, or the heating power control is at a higher level than the processing air volume control, so that a change in the heating power will automatically lead to a change in the amount of processing air entering or leaving the processing chamber.

15. The method of claim 12, wherein, The heating device (26-37) has a recirculating air recirculator (28, 30, 32) and / or a fresh air recirculator (34), wherein purified gases resulting from combustion are supplied to the recirculating air recirculator (28, 30, 32) and / or the fresh air recirculator (34); and The fresh air branches upstream and / or downstream of the heat exchanger (35) of the fresh air recirculator (34) via another fresh air duct (76), and enters into the corresponding circulating air duct (40, 42, 44) downstream of the heat exchanger (29, 31, 33) of the corresponding circulating air recirculator (28, 30, 32).

16. The method according to any one of claims 12 to 15, wherein, The amount of processed air is controlled according to at least one parameter, the parameter being selected from: - The number and / or weight and / or type and / or surface area of ​​the workpieces (14) contained in the processing chamber (18); - The number and / or weight and / or type and / or surface area of ​​the workpieces (14) delivered to the processing chamber (18) per unit time; - Volumetric flow rate, mass flow rate, temperature, quality and / or quantity of the processing medium and / or processing fluid; - The content of harmful substances and / or temperature and / or humidity of the processed air in the processing chamber (18); and - The content of harmful substances and / or temperature and / or humidity of the exhaust gas discharged from the treatment chamber (18).

17. The method according to any one of claims 12 to 15, wherein, The heating power of the heating device is controlled according to at least one parameter, the parameter being selected from: - The number and / or weight and / or type and / or surface area of ​​the workpieces (14) contained in the processing chamber (18); - The number and / or weight and / or type and / or surface area of ​​the workpieces (14) delivered to the processing chamber (18) per unit time; - The content of harmful substances and / or temperature of the exhaust gas discharged from the processing chamber (18); - The content of harmful substances and / or temperature of the pure gas discharged from the heating device (26-37) to the outside; - The temperature difference between the circulating air exported from the processing chamber and the air introduced back into the processing chamber; - The temperature difference between the exhaust gas supplied from the processing chamber (18) to the combustion chamber (37) of the heating device and the pure gas discharged from the combustion chamber; - Position of the pure gas valve or dispensing valve.

18. The method of claim 13 or 14, wherein, The heating power is adapted without detecting additional measurement parameters relating to the concentration of harmful substances in the process air introduced into and / or extracted from the process chamber (18).

19. The method of claim 12, wherein, The workpiece processing equipment (10) is used for drying and / or hardening painted and / or coated and / or bonded workpieces.

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