EP2844937B2 - System having a process chamber for workpieces - Google Patents

Description

The invention relates to a system with a process chamber, which has an interior with a receiving area for workpieces and with an opening for feeding in or removing workpieces, with a device for blowing gaseous fluid into the interior, which has at least one nozzle or orifice for generating a fluid flow curtain between the opening and the receiving area for workpieces, and which has a device for circulating gaseous fluid in the receiving area through a circulating air line system communicating with the receiving area, which has a supply channel opening into the receiving area and a supply channel connected to the receiving area Has return channel, in which the circulated gaseous fluid is guided through a device for tempering, in particular for heating gaseous fluid from the receiving area.

The invention also relates to a method for operating such a system, in which pressurized gaseous fluid is passed through the nozzle or orifice to generate the fluid flow curtain.

Such a plant is from DE 24 54 091 A1 known. This system has a process chamber with an inlet opening and an outlet opening, in each of which there is a fluid flow curtain. The fluid flow curtain here consists partly of fresh air that can get into the interior of the process chamber. Such a system also describes the JP 2008 134014 A .

In the WO 2010/122 121 A1 describes a system for drying workpieces, which has a process chamber for tempering workpieces, which is closed at an inlet opening and at an outlet opening with a fluid flow curtain. The process chamber is also fed here with the fresh air from the fluid flow curtain.

Also the GB 2 123 936 A describes a system for drying workpieces in a process chamber which receives fresh air through a fluid flow curtain at the inlet opening and the outlet opening.

In production facilities for painting and coating vehicle bodies, drying systems are used to dry vehicle bodies that have been freshly painted or coated with anti-corrosion protection. These systems have a process chamber designed as a drying tunnel into which hot air is blown. There is a drying zone in the dryer tunnel. The drying zone is a receiving area for workpieces in the form of vehicle bodies. In order to dry the vehicle bodies, they are moved through the drying tunnel on a conveyor. The layer of paint or coating to be dried on the vehicle body can be affected by contamination, in particular dust particles. Furthermore, gaseous fluid and with it heat can escape from the interior through an opening for the supply of workpieces.

The object of the invention is to provide a system with a process chamber that has an interior space with a receiving area for workpieces that can be opened at least partially, in which simple means can be used to efficiently separate this interior space from the environment and at the same time an adequate supply of fresh air for the recording area can be guaranteed.

This object is achieved by a system having the features of claim 1 and a system having the features of claim 3 and by a system having the features of claim 13 and by a system having the features of claim 14. This object is also achieved by a method having the features of claim 15.

Advantageous embodiments of the invention are specified in the dependent claims.

The term fresh air is understood to mean, in particular, pre-compressed, heated and/or thermally and/or mechanically cleaned and/or dried air with a filter, the state parameters of which are adjusted as required. Fresh air can B. also be treated exhaust air from a process chamber. In addition, fresh air can also be the exhaust gas from a heat engine or internal combustion engine. By supplying fresh air to the receiving area of the process chamber, it can be ensured that the solvent content of the air inside the process chamber when drying workpieces does not exceed threshold values above which drying processes are impaired and above which flammable solvents from paints, varnishes, adhesives and/or Coatings can cause explosions because an explosive limit is exceeded.

The invention is based on the idea that at least one air lock of a process chamber in a drying system fulfills a double task: Fresh air fed into the air locks, which creates a fresh air curtain, can serve to separate the interior from the environment in terms of flow and/or thermally. On the other hand, the fresh air from the fresh air curtain can be used to sufficiently dilute the solvent released in the process chamber during drying processes by feeding this fresh air into the process chamber.

Since the first task is load independent and the second task dependent, the inventors propose to separate this dual task of the airlocks. In this case, a volume flow of fluid conducted into the process chamber should be reduced or increased in accordance with the utilization of the process chamber. In particular, fresh air and/or recirculated exhaust air can be considered as fluids. If a fresh air flow supplied to the process chamber of a drying system is heated to a dryer temperature, adapting the fresh air volume flow to the load allows the fresh air volume flow to be temporarily lowered below its maximum value and thus lower the energy consumption.

The system has a device for circulating gaseous fluid in the receiving area through a circulating air line system communicating with the receiving area, which is guided through a device for tempering, in particular for heating gaseous fluid from the receiving area. The fresh air supplied to the process chamber can e.g. B. before or after a heat exchanger in the device for be fed into the circulating air system for temperature control. However, it is also possible to feed the fresh air into a line section of the circulating air line system, through which circulating air is routed from the process chamber to the device for temperature control or through which circulating air tempered in the device for temperature control can get into the process chamber.

The system contains a device for supplying fresh air into the receiving area, which has at least one line with an opening for sucking in fresh air. In an embodiment of the system according to the invention, the line can be connected to the circulating air line system. In this case, a circulating air fan can be used alternately or simultaneously to convey fresh air at low cost. A flow control device is provided in the circulating air line system, with the flow control device advantageously being arranged in a supply duct or a return duct of the circulating air line system. The flow control device can e.g. B. include a throttle valve and / or an adjustable fan. In a possible embodiment of the system according to the invention, a heat exchanger and a heating device are provided in the circulating air line system. The heat exchanger can transfer heat from an exhaust gas flow into a fresh air flow within the device for supplying fresh air to the receiving area. A heater can, for. B. connected to a solar thermal system and / or with a gas burner.

The line with the opening for sucking in fresh air can, in particular, open into a supply duct or return duct within the circulating air line system.

The system may also include a device for supplying fresh air to the receiving area, comprising at least one duct with an opening for sucking in fresh air, which is connected directly to the process chamber.

The flow control device is preferably part of a (superordinate) control or regulating circuit that supplies the receiving area with conditioned fluid, in particular with fresh air and possibly recirculated, treated exhaust air. The flow control device can be directly or indirectly connected to a control or regulating circuit that contains a device for detecting a status parameter of the process chamber and that controls or regulates the amount of fresh air introduced into the receiving area by means of the flow control device.

1. i. Kohlenstoffgehalt und/oder Lösemittelgehalt der Atmosphäre in dem Aufnahmebereich;
2. ii. Anzahl und/oder Gewicht und/oder Typ und/oder Größe der Oberfläche von in dem Aufnahmebereich angeordneten Werkstücken;
3. iii. Anzahl und/oder Gewicht und/oder Typ und/oder Größe der Oberfläche von dem Aufnahmebereich pro Zeiteinheit zugeführten Werkstücken;
4. iv. Temperatur der Abluft eines Brenners in einer Einrichtung für das Temperieren von Umluft;
5. v. Temperaturdifferenz von gasförmigem Fluid, das dem Aufnahmebereich entnommen und das dem Aufnahmebereich wieder zugeführt wird;
6. vi. Temperaturdifferenz von gasförmigem Fluid aus dem Aufnahmebereich, das einer Brennkammer eines Brenners in einer Einrichtung für das Temperieren von Umluft zugeführt wird, und von Abluft aus der Brennkammer des Brenners;
7. vii. Wärmemenge pro Zeiteinheit, die der Prozesskammer zugeführt wird.

The process chamber in the plant may contain a device for monitoring an operation of the process chamber, which is designed for detecting a condition parameter from the group given below:

1. i. carbon and/or solvent content of the atmosphere in the receiving area;
2. ii. number and/or weight and/or type and/or size of the surface of workpieces arranged in the receiving area;
3. iii. number and/or weight and/or type and/or size of the surface of workpieces fed to the receiving area per unit of time;
4. IV. Temperature of the exhaust air from a burner in a device for tempering circulating air;
5. v. Temperature difference of gaseous fluid that is removed from the receiving area and that is returned to the receiving area;
6. vi. Temperature difference of gaseous fluid from the receiving area, which is supplied to a combustion chamber of a burner in a device for tempering circulating air, and of exhaust air from the combustion chamber of the burner;
7. vii. Amount of heat per unit time that is supplied to the process chamber.

The process chamber in the system can also be designed with a receiving area that is divided into a first receiving area and a further receiving area, wherein the device for injecting gaseous fluid into the interior creates a fluid flow curtain between the first receiving area and the further receiving area.

The device for injecting gaseous fluid into the interior of the process chamber contains at least one nozzle or at least one orifice for creating a fluid flow curtain between the opening and the receiving area for workpieces. The at least one nozzle or at least one screen preferably serves as an outlet opening for air (or a correspondingly processed inert gas such as CO ₂ or N ₂ ) that has been heated above ambient temperature and/or compressed above ambient pressure.

The process chamber can e.g. B. contain gaseous fluid whose temperature T is above 100 ° C and / or for which a temperature difference to the environment of the process chamber is more than 50 ° C. In one exemplary embodiment, fluid flows into the process chamber approximately vertically from top to bottom. In a further preferred exemplary embodiment, the fluid flowing in through the nozzle has a temperature that is more than 20° C. higher or lower than the (approximately still) fluid contained in the process chamber. In the following, reference is mainly made to a rigid or adjustable nozzle geometry, in which case the invention can also be implemented in each case with one or more simple screens.

The interior of the process chamber is preferably designed in the form of a tunnel. It has a floor and a ceiling. By the at least one nozzle as a slot nozzle with a substantially rectangular outlet cross section is configured, the gaseous fluid can be supplied via the ceiling of the interior space with a flow direction oblique in relation to the floor in such a way that a flow roll of air is formed on the side of the fluid flow curtain pointing towards the floor or the inlet opening, which is at least partially injected fluid is mixed.

One idea of the invention is in particular that the fluid flow curtain can be produced with a reduced energy consumption if the gaseous fluid blown into the interior space via the at least one nozzle is guided on a guide contour that protrudes into the interior space. It is particularly advantageous if this guide contour can be pivoted. This makes it possible to adjust the fluid flow curtain in relation to the horizontal. An angle of between 80° and 50° is preferably set between the outflow direction and the horizontal.

When this angle is adjusted between the outflow direction and the horizontal, the fluid flow curtain creates a flow roll on its lower side, viewed in the flow direction, which faces the bottom or an opening. The fluid flow of the fluid flow curtain pushes against the gaseous fluid residing in the area of the bottom of the process chamber. The fluid flow of the fluid flow curtain interferes with and mixes with fluid exiting the process chamber in the area of the floor. In particular, by pivoting the guide contour, it can be achieved that workpieces are not adversely affected when entering or exiting the process chamber.

It is particularly advantageous if a wall is arranged on the side of the guide contour pointing towards the opening, which wall defines a diffuser with the guide contour, which contains a mixing chamber. The diffuser is designed asymmetrically with respect to the mean flow direction of the gaseous fluid from the at least one nozzle. The mixing chamber in the diffuser is located on the down-stream side of the fluid flow from the nozzle.

The mixing chamber is positioned within the diffuser such that fluid on a side of the fluid flow curtain facing the orifice (i.e., outward from the interior of the process chamber) is mixed with air from the area of the orifice. The air is sucked into the roller by the gaseous fluid flowing through the nozzle or the screen.

The wall may have one or more openings for passage of circulating air from the area of the opening.

By forming an auxiliary chamber acting as a “dead space” for gaseous fluid on a side of the guide contour facing away from the mixing chamber, it can be ensured that the stream of gaseous fluid exiting the nozzle or orifice is guided along the guide contour without a flow break-off. In the “dead space” there are preferably lower flow velocities than outside the dead space. By arranging an additional guide vane in the mixing chamber, large amounts of fluid can be returned from the flow roller into the fluid flow curtain.

By arranging an end wall on the side of the guide vane pointing to the inlet opening, which defines a retention space with the guide contour, circulated air from the area of the inlet opening, which is directed in the area of the guide vane into an edge area of the interior, can be prevented from escaping to the outside be held back.

Conveniently the end wall has one or more openings for the passage of recirculated air from the area of the inlet opening. The at least one nozzle may include means for adjusting the rate of flow of fluid through the nozzle. By providing a plurality of nozzles with means for adjusting the flow rate of fluid passing through the nozzle, the curtain of fluid flow between the entrance opening and the workpiece receiving area can be adjusted differently in different sections.

The device for blowing gaseous fluid may have a heater for heating the gaseous fluid. This makes it possible to ensure that no condensate, e.g. B. Condensation occurs. The process chamber is suitable for use in a drying and/or hardening system. In particular, the process chamber can be integrated into a paint shop.

In the process chamber, the fluid flow curtain is created with gaseous fluid that is pressurized and guided through a nozzle. In this case, in the mixing chamber arranged adjacent to the nozzle, air from the area of an opening of the process chamber is admixed to the gaseous fluid flowing out of the nozzle. The gaseous fluid guided through the nozzle is guided along a guide contour delimiting the mixing chamber. This guiding contour separates the mixing chamber from an adjacent secondary chamber which acts as a dead space for gaseous fluid.

In particular, the process chamber can be operated in such a way that a flow of gaseous fluid guided through a nozzle is throttled or interrupted to create a fluid flow curtain between the opening and the receiving area for workpieces and/or in which the direction of the fluid flow curtain is changed when a workpiece is moved through the opening. This ensures that the curtain of fluid flow does not damage the surface of the coating of workpieces being moved in and out of the process chamber.

The invention is explained in more detail below with reference to the exemplary embodiments shown schematically in the drawing.

Fig. 1

eine erste Trocknungsanlage für Fahrzeugkarossen;

Fig. 2

einen Längsschnitt einer Schleuse der Trocknungsanlage;

Fig. 3

eine dreidimensionale Ansicht der Schleuse;

Fig. 4

die Strömungsverhältnisse für Luft im Bereich der Schleuse;

Fig. 5

einen Längsschnitt einer weiteren Schleuse für eine Trocknungsanlage;

Fig. 6

und Fig. 7 sowie Fig. 8 Abschnitte weitere Längsschnitte alternativer Ausführungsformen für Schleusen in einer Trocknungsanlage;

Fig. 9

einen Querschnitt eines Trocknertunnels in einer Trocknungsanlage;

Fig. 10

einen Längsschnitt einer weiteren Schleuse;

Fig. 11

eine zweite Trocknungsanlage für Fahrzeugkarossen; und

Fig. 12

bis Fig. 17 weitere alternativ aufgebaute Anlagen für das Trocknen von Werkstücken.

Show it:

1

a first vehicle body drying facility;

2

a longitudinal section of a lock of the drying system;

3

a three-dimensional view of the lock;

4

the flow conditions for air in the area of the lock;

figure 5

a longitudinal section of another lock for a drying system;

6

and 7 as well as 8 Sections further longitudinal sections of alternative embodiments for locks in a drying system;

9

a cross section of a dryer tunnel in a drying plant;

10

a longitudinal section of another lock;

11

a second vehicle body drying facility; and

12

until 17 other alternatively constructed systems for drying workpieces.

In the 1 Plant 1 shown for drying z. B. metallic workpieces is designed in particular for vehicle bodies 3. The system 1 comprises a process chamber designed as a drying tunnel 5 . The vehicle bodies 3 , which are mounted on skids 7 , can be moved through the drying tunnel 5 by means of a conveyor device 9 . The conveyor device has an electric drive 10. The dryer tunnel 5 is lined with sheet metal. It has an entry lock 11 with an inlet opening 12 and an exit lock 13 with an outlet opening 14 . The drying zone 15 is a receiving area for workpieces. The drying zone 15 is preferably designed in such a way that about fifteen vehicle bodies 3 freshly coated with a paint and/or a substrate containing a solvent can be dried more or less simultaneously therein. For this purpose, the drying section 15 z. B. with the length L = 40 m, a clear width b with 1.40 m <b <2.70 m and a clear height h with 2.00 m <h <2.60 m. In a particularly preferred embodiment, a tunnel length of 78 m (width b outside: 3 m to 4.6 m, height h outside: 2.8m to 3.3m). Fluid is fed into the drying section 15 for drying by means of a device 70 for providing conditioned gaseous fluid.

The device 70 preferably contains a circulating air line system 72 communicating with the drying zone 15. The circulating air line system 72 communicates with the receiving area 15 and has a supply duct 75 acting as a circulating air return duct and contains a return duct 77 which serves as a circulating air return duct for returning the circulating air. The circulating air line system 72 is routed through a heating device 63 . In the device 70 there is a fan 61 with which the air is blown in for drying. With the device 70, the air in the drying zone 15 can be kept at a defined temperature in a circulating air operating state.

The system 1 preferably contains a device 74 and, alternatively or additionally, a device 74' for the supply of fluid in the form of possibly also conditioned fresh air. The device 74, 74' has a line 76, 76' with an opening 78, 78' for the intake of fresh air. In the line 76, 76' there is a flow control device 80, 80' which is designed as a butterfly valve. The line 76, 76' is advantageously connected to the circulating air line system 72.

In order to remove evaporating solvent from the fluid atmosphere in the drying tunnel 5 from paint, adhesives or coatings of the vehicle bodies 3, there is a line 65 or also several lines for exhaust air in the plant 1, via the air contaminated with solvent from the drying tunnel 5 to a cleaning reactor 67 can be supplied.

In the inlet lock 11 and the outlet lock 13 of the dryer tunnel 5 there is a nozzle 17, 19 for generating a fluid flow curtain 21, 23. The nozzles 17, 19 are ventilated by a fan acting as a compressor for fresh air 25, 27 through a ceiling 6 of the dryer tunnel 5 arranged chamber 29, 31 supplied with fresh air. The nozzles 17, 19 preferably have a narrow slit-shaped opening 33, 35, which is in the Substantially over the width of the dryer tunnel 5 or over the width of the inlet and outlet openings 12, 14 extends. The slit-shaped opening 33, 35 of the nozzles 17, 19 opens into the interior 39 of the dryer tunnel 5. The fluid flowing out of the nozzles 17, 19 is guided into the interior of the dryer tunnel 5 via a diffuser 16, 18. The diffuser 16, 18 extends in front of the nozzles 17, 19 across the width of the inlet and outlet openings 12, 14. The diffuser 16, 18 is designed asymmetrically with respect to the direction of the fluid flow curtain 21, 23 and is provided with a guide plate a guide contour 211 and an end wall 215 limited. The fluid flowing out of the nozzles 17, 19 is guided into the interior of the dryer tunnel at the guide contour 211 of the guide plate. A temperature sensor 69, 71 is located on the guide contour 211 for advantageously possible detection of the temperature T of the fluid supplied to the interior 39 via the nozzles 17, 19.

The fluid flow curtain 21, 23 preferably runs at an angle of 50°≦α≦80° to the horizontal 37. It is directed into the interior 39 of the dryer tunnel 5. The fluid stream flowing out of the nozzles 17 , 19 widens towards the bottom 41 of the dryer tunnel 5 . As the distance from the opening 33, 35 of the nozzles 17, 19 increases, the speed of the flow of the fresh air forming the fluid flow curtain 21, 23 as a gaseous fluid decreases. The fluid flow curtain 21, 23 separates the gas atmosphere in the interior 39 of the dryer tunnel 5 from the ambient air 42. The fluid flow emerging from the nozzles 17, 19 is adjusted to a predetermined shape by means of a control device 45, 47.

A solvent sensor 73 is arranged in the drying zone 15 for detecting the concentration of solvent in the gas atmosphere of the dryer tunnel 5 . Alternatively or additionally, such a solvent sensor can be arranged in the exhaust air duct 65 . The gaseous fluid in the form of air supplied to the nozzles 17, 19 is preheated in a heating device 43, 44 to a desired process temperature T _set , which is preferably in a temperature range of 160° C.≦T _set ≦250°C. Because the fluid flow curtain 21, 23 consists of fresh air, it can be ensured that a lower explosion limit for organic solvents in the drying zone 15 of the dryer tunnel 5 is not exceeded. The preheating of the supplied fluid has the effect that no condensate forms in the inlet lock 11 and the outlet lock 13 of the drying tunnel 5 .

In order to ensure that the explosion limit in the drying zone 15 is maintained, fresh air can be introduced into the drying section 15 via the device 74 or 74' if required.

The control device 45 is connected to the flow control device 80 for adjusting the quantity of fresh air fed into the dryer tunnel 5 via the device 74 or 74 ′. With the control device 45, the fresh air supplied via the line 76 or 76' is set to a predetermined value. The fresh air supply is adjusted as a function of the number of vehicle bodies moved through the drying zone 15 of the dryer tunnel 5 per unit of time and/or on the basis of the signals from the temperature sensors 69, 71 and/or the solvent sensor 73, which is detected by a sensor 49, 51 as a process chamber operating state parameter and/or one or more other process chamber operating state parameters that enable statements to be made about the composition of the gas atmosphere in the dryer tunnel 5 and thus the determination of the fresh air requirement when the dryer tunnel 5 is operated. The supply of fresh air is adjusted in such a way that the so-called lower explosion limit of the composition of the gas atmosphere in the drying tunnel 5 is not exceeded when the system 1 is in operation.

In order to detect process chamber operating state parameters, a light barrier for determining the number of vehicle bodies moved through the dryer tunnel 5 per unit of time can be provided in a modified embodiment of the system 1 as an alternative to the sensor 49 . As an alternative or in addition to the sensor 49, it is also possible to equip the system with a measuring device with which the weight of the vehicle bodies 3 fed to the dryer tunnel 5 can be determined and/or to provide a device with which the size of the vehicle bodies provided with a surface coating Surface of the vehicle bodies 3 can be detected. In addition, the system 1 can also be equipped with a device for detecting a workpiece, z. B. the vehicle bodies 3 or on a skid 7 mounted digital code, z. B. be equipped with a barcode, the digital information about the size and nature of a on a workpiece, z. B. on a vehicle body 3 applied surface coating or on a certain type of workpiece.

In a system according to the invention, the determination of the fresh air requirement of the process chamber, in particular of a drying tunnel for motor vehicle bodies, can be carried out on the basis of a predefined type of workpiece, for example as follows:
The mass and number of the workpieces present in the process chamber or on the way into the process chamber are determined via a mass detection device and a number of pieces detection device. A workpiece type is stored in the control device 45 for each measured value of the mass of a workpiece, taking into account expected fluctuations that come into consideration on the basis of the workpieces treated in the system. The size of the painted surface of this workpiece can then be deduced in the control device 45 from the type of workpiece determined in the control device 45 . The relevant value for the size of the surface can then be used to determine the values emitted by this surface A fresh air requirement of the process chamber can be defined, which is necessary so that z. B. the proportion of combustible solvent in the gas atmosphere of the process chamber 15 remains below the explosion limit.

According to the invention, a specific workpiece, d. H. closed a specific workpiece type. A quantity of paint or coating applied to the specific workpiece is then assumed and a quantity of solvent absorbed in the paint applied to the workpiece or the coating arranged thereon is then deduced from this assumed quantity of paint or coating.

In combination with the number of workpieces in question in the process chamber, a total amount of solvent that is introduced into the process chamber during the drying of workpieces can then be determined. From this, the fresh air requirement for the process chamber can be determined in order to operate it below the explosion limit.

It should be noted that a device for detecting the mass and number of workpieces according to the invention z. B. can be designed as a weighing device with which the number of weighing operations is recorded.

In order to take account of the thermal inertia of the overall system, it is advantageous to attach a device for detecting a workpiece parameter in front of the process chamber. In the time remaining until a workpiece enters the process chamber, e.g. B. via the amount of fresh air introduced into the process chamber in the process chamber, a desired process temperature and / or a desired composition of the gas atmosphere can be adjusted.

It should also be noted that the thermal inertia of a system described above is essentially determined by the heat capacity of the process chamber and the size of the air quantities supplied to and removed from it.

By connecting the aforementioned devices to the control device 45, it is possible to control or to control the composition of the gas atmosphere by adjusting the fresh air supply in accordance with the requirements of the vehicle bodies 3 arranged in the drying tunnel 5, in particular taking into account the solvent content in the surface coating of the vehicle bodies 3 rules.

• Betriebszustand 1:
  Mit dem Fluidstromvorhang 21, 23 wird in die Eingangs- bzw. Ausgangsschleusen 11, 13 ein konstanter Frischluft- Volumenstrom zugeführt, der nicht nur eine hinreichende Abdichtung des Innenraums 39 gewährleistet, sondern auch eine ausreichende Verdünnung eines Lösemittelgehalts in der Atmosphäre der Trocknungszone 15. Der Trocknertunnel 5 wird hier auslastungsunabhängig mit dem Volumenstrom beaufschlagt, der für die bei Vollauslastung zugeführte Lösemittelmenge erforderlich ist.
• Betriebszustand 2:
  Mit dem Fluidstromvorhang 21, 23 wird in die Eingangs- bzw. Ausgangsschleusen 11, 13 ein konstanter Frischluft- Volumenstrom zugeführt, der eine hinreichende Abdichtung des Innenraums 39 gewährleistet. Um eine ausreichende Verdünnung des Lösemittelgehalts in der Atmosphäre der Trocknungszone 15 zu gewährleisten, wird mittels der Einrichtung 74 zusätzliche Frischluft zugeführt. Die Menge der mit der Einrichtung 74 zugeführten Frischluft wird mit der Steuereinrichtung 45 eingestellt und ändert sich mit der Auslastung der Anlage 1. Wenn der Trocknungszone 15 vermehrt Frischluft zugeführt wird, muss aus dem Trocknertunnel 5 gleichzeitig eine entsprechende Menge Abluft über die Leitung 65 entnommen werden, damit die Anlage 1 im Gleichgewicht ist und in dem Trocknertunnel 5 keine Über- oder Unterdrücke entstehen.

The plant 1 can thus z. B. be operated in the following operating states:

• Operating state 1:
  With the fluid flow curtain 21, 23, a constant fresh air volume flow is fed into the inlet and outlet locks 11, 13, which not only ensures adequate sealing of the interior 39, but also a sufficient dilution of a solvent content in the atmosphere of the drying zone 15. The Dryer tunnel 5 is subjected to the volume flow required for the amount of solvent supplied at full capacity, regardless of capacity utilization.
• Operating state 2:
  With the fluid flow curtain 21, 23, a constant volume flow of fresh air is fed into the inlet and outlet locks 11, 13, which ensures that the interior space 39 is adequately sealed. In order to ensure a sufficient dilution of the solvent content in the atmosphere of the drying zone 15, additional fresh air is supplied by means of the device 74. The amount of fresh air supplied with the device 74 is set with the control device 45 and changes with the utilization of the system 1. If the drying zone 15 is increasingly supplied with fresh air, a corresponding amount of exhaust air must be removed from the dryer tunnel 5 at the same time via the line 65 , so that the system 1 is in balance and in the dryer tunnel 5 no positive or negative pressures arise.

The 2 12 is a sectional view of the entry lock 11 of the drying plant 1. FIG 1 . The nozzle 17 in the entry lock 11 is a slit nozzle. The fresh air heated in the heating device 44 is supplied to the nozzle 17 via a pipe 201 . The pipeline 201 opens into a chamber 203. In the chamber 203, the fresh air is conducted to the nozzle 17 via the air filter 205 and a housing sheet metal 206 arranged at an angle. There is a guide plate 207 in the lock 11. The guide plate 207 is firmly connected to the housing plate 206. The guide plate 207 and the housing plate 206 can be pivoted in the lock 11 about an axis of rotation 208 in the direction of the arrow 214 . Pivoting the guide plate 207 with the housing plate 206 opens access to the filter 205 so that maintenance work can be carried out there. The nozzle 17 has a slit-shaped opening 209. The slit-shaped opening 209 of the nozzle 17 is arranged set back with respect to the ceiling 6 of the drying tunnel 5. This makes it possible to avoid impairments and damage to a coating of vehicle bodies that has not yet dried, even at high flow speeds of a fluid stream emerging from the nozzle 17. which are moved through the entry lock 11 into the dryer tunnel 5. A comparatively large distance between the opening 209 of the nozzle 17 and the floor 41 of the drying tunnel 5 is important for avoiding such damage. This ensures that the impulse of the gaseous fluid flowing out of the nozzle 17 is already weakened in the middle of the drying tunnel to such an extent that corresponding coatings of vehicle bodies 3 cannot be damaged by the fluid flow curtain 21 .

The fluid stream 210 emerging from the opening 209 of the nozzle 17 is guided into the interior of the dryer tunnel 5 along the contour 211 of a guide plate 207 acting as a guide vane. The length L of the contour 211 of the guide plate 207 preferably corresponds to 20 to 40 times the slot width B of the nozzle opening 209.

On the side of the contour 211 pointing to the inlet opening 213 of the dryer tunnel 5 there is an end wall 215. The end wall 215 extends over the width of the lock 11. The end wall 215 delimits the contour 211, a ridge element 212 and the contour 211 of the guide plate 207 the diffuser 16. The diffuser 16 is designed asymmetrically with respect to the main flow plane 202 of the fluid flowing out of the nozzle 17. The main flow plane 202 and the contour of the guide plate 211 are at an angle φ to one another. The section of the diffuser 16 which lies on the side of the plane 204 which is symmetrical to the contour of the guide plate 211 in relation to the main flow plane 202 and which encloses the angle 2ϕ with the contour of the guide plate 211 and which faces the end wall 215, acts as a mixing chamber 217 for gaseous fluid 219. The mixing chamber 217 is set back with respect to the roof 6 of the dryer tunnel 5. The diffuser 16 with the mixing chamber 217 is located in the lock 11 above the inlet opening 213. The mixing chamber 217 is the inlet opening 213 adjacent. The guide plate with the contour 211 separates the mixing chamber 217 from a secondary chamber 216. The secondary chamber 216 opens into the interior 39 of the dryer tunnel 5. The secondary chamber 216 forms a dead space for air from the dryer tunnel 5. The on the back of the guide plate with the guide contour 211 formed secondary chamber causes the fluid flow 210 is guided on the Leitkontur 211 due to the Coanda effect without flow separation.

The 3 13 is a three-dimensional view of the entry lock 11 from FIG 2 . The slit-shaped opening 209 of the nozzle 17 extends over the entire width of the inlet opening 213 of the dryer tunnel 5. The slit-shaped opening 209 of the nozzle 17 is so narrow that the fluid flow emerging from the nozzle 17 forms a fluid flow curtain over a wide flow range with different exit velocities . This fluid flow prevents in particular an entry of dirt particles 301 from the environment in the 1 shown drying plant 1 into the interior of the drying tunnel 5.

The 4 shows the flow conditions for air in the inlet lock 11 in the plane of a longitudinal section of the dryer tunnel 5 with arrows 1 . The fresh air supplied to the dryer tunnel 5 via the slot-shaped nozzle 17 causes a fluid flow curtain 401 on the outlet side of the nozzle 17. Starting from the opening 209 of the nozzle 17, the fluid flow curtain 401 of fresh air flowing in the direction of the arrows 402 extends in the form of a curved lobe 403 to the bottom 41 of the entry lock 11. The lobe 403 has a thickness D at the height H of the center of the entry lock 11, which is determined by the width B of the opening 209 of the nozzle 17. On the side of the fluid flow curtain 401 pointing towards the inlet opening 213 of the dryer tunnel 5, the fresh air flowing out of the nozzle 17 generates a flow roll 407 of air. In the flow roller 407, the air flows around a center 409 in a flow direction indicated by the arrows 406. The air in the area of the center 409 is essentially still. The air circulated in the flow roller 407 is at least partially mixed with the fresh air blown in via the nozzle 17 . The flow roller 407 extends from the floor 41 to the ceiling 6 of the entrance lock 11.

A diffuser 16 is formed by the baffle plate 211 on the one hand and the end plate 215, which is arranged on the side of the baffle plate 211 pointing towards the inlet opening 213, on the other hand. The diffuser 16 preferably takes up part of the air circulated in the flow roller 407 within its mixing chamber 217 . In the mixing chamber 217, part of this air is entrained and mixed with the gaseous fluid flowing out of the orifice 209 of the nozzle 17, in the manner of a Venturi effect. This increases the volume flow of the fluid flow curtain 401 in the area of the arrows 402. The volume flow of the fluid flow curtain 401 can consist of 30% or more gaseous fluid, which is supplied to the fluid flow flowing out of the nozzle 17 via the mixing chamber 217. The consequence of this is that a fluid flow curtain 401 extending as far as the bottom 41 of the dryer tunnel 5 can be generated even with a comparatively small amount of fresh air blown in.

The air from the mixing chamber 217 is fed back to the flow roller 407 in this way. The consequence of this process is that only a small proportion of the gaseous fluid fed into the interior 39 of the dryer tunnel 5 via the nozzle 17 leaves again through the opening 213 of the lock 11 of the dryer tunnel 5 . The gaseous fluid flowing out of the nozzle 17 thus reaches the interior of the dryer tunnel 5 for the most part in the direction of the arrows 408. By means of the gaseous fluid flowing out of the nozzle 17, a barrier is created in the area of the opening 213 of the lock 11 in the flow roller 407 circulated air generated. This barrier causes a thermal separation of the interior 39 of the dryer tunnel 5 from the exterior. In addition, this barrier also prevents the entry of dust and dirt particles into the interior 39 of the dryer tunnel 5.

The figure 5 shows a modified embodiment of a lock 501 for a drying system. The lock 501 has a nozzle 503 for supplying fresh air with a compared to the lock 11 from 1 modified nozzle geometry. The nozzle 503 is a double chamber nozzle. The nozzle 503 has a slit-shaped nozzle opening 505 and a slit-shaped nozzle opening 507, each of which extends over the entire width of the ceiling 509 of the entrance lock 501. The nozzle 503 includes a pivotable control flap 511. The control flap 511 can be moved by means of a spindle drive that is not shown in any more detail. However, an adjustment mechanism with a shaft or a cable pull is also suitable for moving the control flap. By pivoting the control flap 511, the fresh air supplied to the nozzle 503 via the chamber 513 can be guided selectively through the nozzle opening 507, the nozzle opening 509 or through the nozzle openings 507, 509 simultaneously. This makes it possible to dose the air flow emerging from the nozzle openings 507, 509. For example, it is possible by means of the control flap 511 to vary the air flow from the nozzle 503 according to the position of vehicle bodies in the area of the inlet opening of a drying tunnel. With this measure it can be achieved that a layer of paint applied to a vehicle body is not impaired by the fluid flow formed with fresh air from the nozzle 503 . In addition, the thickness D of the fluid flow curtain and thus the quantity and/or the speed of the fresh air fed into the interior of the drying tunnel can be adjusted with the control flap 511 .

In a modified configuration of the entry lock 501, a nozzle with a plurality of nozzle openings and with a plurality of control flaps can also be provided in order to adjust a flow of fresh air for a dryer tunnel.

The 6 12 shows a section of an alternative embodiment for a lock 601 with a nozzle 603 to form an air curtain in the entrance or exit area of a drying plant.

The nozzle 603 in the sluice 601 is assigned a guide plate 605 which acts as a guide vane and is preferably arranged in a pivotable manner. The guide plate optionally has an outer contour that is curved at least in sections. In particular, it extends over the entire width of the nozzle 603. The pivotable baffle plate 605 at the opening 607 of the nozzle 603 is pivotably mounted on the cover 608 of the lock 601 at a rotary joint 615. The pivotable guide plate 605 protrudes into the interior 611 of the lock 601. The length L of the contour of the guide plate 605 corresponds to approximately 20 to 40 times the slot width B of the nozzle opening. A front wall 609 is in turn arranged in the lock 601 opposite the pivotable guide plate 605 . The pivotable guide plate 605 and the end wall 609 together with a ridge element 612 also define a diffuser with a mixing chamber 613 here. Due to the pivotability of the guide plate 605, the geometry of the diffuser and the mixing chamber 613 in the lock 601 can be changed.

For the pivoting, the guide plate 605 is assigned an actuating drive, not shown in any more detail. By pivoting the guide plate 605 according to the double arrow 617, it is possible to set an angle of attack β in relation to the horizontal 616 and thus the direction of a fluid flow curtain generated with gaseous fluid from the nozzle 603 in the lock 601. The pivoting shifts the baffle plate 605 on which the gaseous fluid flowing out of the nozzle 607 is guided. As a result, the shape of the flow roller can be changed, which is formed on the side of the guide plate 605 pointing to the opening 619 of the lock 601 due to the fluid flowing out of the nozzle 603 . By pivoting the guide plate 605 towards the cover 608 of the lock 601, a comparatively shallow inflow of gaseous fluid into the lock can be brought about. By moving the guide plate 605 up and down, the flow direction of the fluid flowing out of the nozzle can be adjusted to the position and geometry of vehicle bodies that are moved through the lock 601 into the interior of the drying tunnel. It can thus be achieved that the fluid flowing out of the nozzle is not deflected by the vehicle bodies towards the opening 619 and a layer of paint applied to vehicle bodies which is to be dried in the drying tunnel is not blown away and is not damaged in the drying tunnel.

The 7 shows a section of a further alternative embodiment for a lock 701 with a nozzle 703 in order to form an air curtain in the entrance or exit area of a drying plant. The nozzle 703 opens into a diffuser section, which adjoins the narrowed cross section of the nozzle and thus widens the flow cross section for the fluid. The nozzle 703 with subsequent diffuser section thus has a flow channel 704, the cross section of which extends towards the interior 711 of the lock 701 into a volume which acts as a diffuser and in which a mixing chamber 713 is located.

The structure of the lock 701 otherwise corresponds to that of the lock 601 6 . Corresponding assemblies of lock 601 and 701 are therefore in 7 with compared to 6 reference numbers increased by the number 100. Unlike the end wall 609 of the lock 601 in 6 the sluice 701 has an end wall 709 with one or more inlet openings for ambient air. The end wall 709 preferably has openings in the form of a sieve-like perforation. This measure also allows air to be sucked in from an upper region 721 in the vicinity of the lock 701. The air thus sucked into the lock 701 is preferably mixed with air from a flow roll which forms at the opening of the lock. The air sucked in and part of the air from the flow roller are then mixed into the fluid flow emerging from the diffuser.

The 8 12 shows a section of a further alternative embodiment for a lock 801 with a screen 803 having an opening 804 in order to form an air curtain in the entry or exit area of a drying plant. The structure of the lock 801 corresponds to that of the lock 701 7 . Corresponding assemblies of lock 701 and 801 are therefore in 8 with compared to 7 reference numbers increased by the number 100. The end wall 809, the ridge element 812 and the baffle plate 805 here also delimit a diffuser which comprises a mixing chamber. Unlike the end wall 709 of the lock 701 in 7 the end wall 809 of the lock 801 is designed with a recess 816. This measure also allows air to be taken in from an upper area 821 in the vicinity of the lock 801 into the flow roll generated by the screen 803 at the opening of the lock.

The 9 shows a cross section of an entry or exit lock 901 of a dryer tunnel 900 in a drying plant with a vehicle body 912. The lock 901 has slot-shaped nozzles 903, 905, 907, which are located on the ceiling 910 of the lock 901. The nozzles 903, 905, 907 can be supplied with a fresh air flow 909 via a device for supplying fresh air, which is not shown in detail. In the sluice 901 there are control flaps, by means of which the fresh air flow 909 can be divided into different channels 911, 913 and 915 for the separate loading of the nozzles 903, 905 and 907 with fresh air.

This measure makes it possible to adjust a fluid flow curtain 917 at the openings of a dryer tunnel, which is adjusted according to the passage of workpieces, e.g. B. vehicle bodies over the width B of the opening can be adjusted differently.

The 10 shows a longitudinal section of another lock 1011 for a drying tunnel in a system for drying metal workpieces. According to the 4 the flow conditions for air in the lock 1011 are also indicated here with arrows. The fresh air fed into the dryer tunnel via the slot-shaped nozzle 1017 causes a fluid flow curtain 1401 on the outlet side of the nozzle 1017.

Starting from an opening 1209 of the nozzle 1017, the fluid flow curtain 1401 (preferably consisting of fresh air flowing in the direction of the arrows 1402) extends in the form of a more or less curved club 1403 towards a bottom 1041 of the sluice 1011. On a to the inlet opening 1213 of the sluice 1011-facing side of the fluid flow curtain 1401, the fresh air flowing out of the nozzle 1017 creates a flow roll 1407 of air. In the flow roll 1407, the air flows around a center 1409 in a flow direction indicated by the arrows 1406. The air in the area of the center 1409 is essentially still. The air circulated in the flow roller 1407 is at least partially mixed with the fresh air blown in via the nozzle 1017 . The flow roll 1407 extends from the floor 1041 to the ceiling 1006 of the entrance lock 1011.

The lock 1011 has a curved ridge wall 1215 on the side of a guide plate 1211 which has a guide contour and which faces the inlet opening 1213. The guide plate 1211 and the ridge wall 1215 delimit and partially enclose a diffuser 1210 with a mixing chamber 1217 which is open at the bottom. In the diffuser 1210 is in the embodiment 10 a flow guide element 1218 is positioned in the form of a "flow vane" which, like the opening 1009 of the nozzle 1017, preferably extends over the entire width of the lock 1011. The baffle 1211 separates the diffuser 1210 from a secondary chamber 1216. The secondary chamber 1216 acts as a dead space for air, in which the flow velocities are lower than in the rest of the lock (except for the actually negligible center of rotation 1409 of the flow roller).

A silhouette wall 1220 is arranged on the bottom 1041 of the lock 1011 in the area of the opening 1213 . The silhouette wall 1220 serves in particular as a flow barrier or as a flow guide element on the bottom. The silhouette wall 1220 is preferably made of spring steel or other temperature and/or corrosion-resistant steels. The silhouette wall 1220 can be pivoted or folded down about a (horizontal) axis 1222 according to the arrow 1224 .

According to the invention, the mixing chamber 1217 takes up a small part of the air circulated in the flow roller 1407 . In the mixing chamber 1217, this air is directed to the gaseous fluid flowing out of the opening 1209 of the nozzle 17 with the flow vane 1218 due to a Venturi effect. It is entrained by the gaseous fluid. This increases the volume flow of the fluid flow curtain 1401 in the area of the arrows 1402. The volume flow of the fluid flow curtain 1401 can thus largely consist of gaseous fluid which is supplied to the fluid flow from the nozzle 1017 via the mixing chamber 1217. As a result, a fluid flow curtain 1401 extending to the bottom 1041 of the dryer tunnel can be generated even with a comparatively small amount of fresh air blown in.

The air from the mixing chamber 1217 is fed back to the flow roller 1407 in this way. The result of this process is that only a small proportion of the gaseous fluid fed into the interior 1039 of the dryer tunnel via the nozzle 1017 leaves again through the opening 1213 of the lock 1011 of the dryer tunnel. The gaseous fluid flowing out of the nozzle 1017 thus reaches the interior of the dryer tunnel for the most part in the direction of the arrows 1408 . By means of the gaseous fluid flowing out of the nozzle 1017, a barrier with air circulated in the flow roller 1407 is generated in the region of the opening 1213 of the lock 1011 Thermally separates interior 1039 of the dryer tunnel from the outside area and also prevents dust and dirt particles from entering the dryer tunnel. The silhouette wall 1220 at the bottom 1041 of the sluice 1011 causes the flow roll 1407 to be comparatively narrow. Only when a workpiece is moved into the dryer tunnel is the silhouette wall folded briefly in the direction of the floor 1041 in accordance with the arrow 1220 . It should be noted that, alternatively or additionally, a foldable silhouette wall corresponding to the silhouette wall 1220 can also be arranged in the upper region of the entry opening.

The one in the 11 The system 2001 shown for drying vehicle bodies 2003 has a process chamber in the form of a dryer tunnel 2005. The dryer tunnel 2005 is designed with an inlet lock 2011, an intermediate lock 2012 and an outlet lock 2013. In the dryer tunnel 2005, the intermediate lock 2012 separates a first drying section 2015a from a further drying section 2015b as receiving areas for the motor vehicle bodies, which is adjoined as a further receiving area for motor vehicle bodies by a holding zone 2016 which is arranged in front of the outlet lock 2013.

The structure of the locks 2011 and 2013 corresponds to the structure of the entrance and exit lock 11, 13 in the 1 Plant 1 shown for drying. In at least one lock 2011, 2013 there is a nozzle 2014 for generating a fluid flow curtain 2021 from fresh air, which is directed obliquely into the interior of the dryer tunnel 2005. One or more nozzles 2014 are combined with a diffuser 2018, in particular the diffuser is arranged adjacent to the nozzle outlet and is asymmetrical to a main flow plane through the associated nozzle. By means of an asymmetrical diffuser on the nozzles of the inlet and outlet locks 2011, 2013, a flow roll of air can be generated on a side of the fluid flow curtain pointing to the opening 2015, 2017 of the dryer tunnel 2005, which on the one hand flows out through a line 2019 via the nozzles 2014 injected fluid and ambient air at the openings 2015, 2017. The intermediate lock 2012 has a nozzle 2009 which creates a fluid flow curtain 2020 .

A modified embodiment of the system 2001 can also be designed without asymmetrical diffusers at the nozzles, for example if reduced requirements are placed on the tightness of the sluices. For example, a mechanical closure of the corresponding locks can also be provided.

The system 2001 contains a heating device 2023 designed as a device for thermal exhaust air cleaning, with a line 2025 for supplying hot clean gas from the dryer tunnel 2005 and a heat exchanger 2027, which is used for heating exhaust air from the dryer tunnel 2005. The exhaust air from the dryer tunnel 2005 that is heated in the heat exchanger 2027 can be burned in a combustion chamber 2029 of the heating device 2023 with or without the addition of additional fuel.

The heating device 2023 supplies several heat transfer devices 2031, 2033, 2035, 2037 with heat through a hot gas line 2036 acting as a clean gas line. The heat transfer devices 2031, 2033 and 2035 are coupled to the hot gas line 2036 in a row one behind the other. The heat transfer devices 2031, 2033, 2035 are preferably designed to be largely the same. The device 2037 contains an air/air heat exchanger and is coupled to the hot gas line 2036 as the last of the heat transfer devices. The device 2037 is used for tempering the fresh air that is led to the nozzles 2014 for generating the fluid flow curtain 2021 from fresh air. The devices 2031, 2033 and 2035 each contain a heat exchanger 2039 connected to the hot gas line 2036 by a hot gas line 2038 and are designed for the circulation of circulating air in the drying sections 2015a, 2015b and in the holding zone 2016. In the heat exchangers 2039, the circulating air is tempered, which is guided through a circulating air line system 2041 communicating with the receiving areas 2015a, 2015b and 2016 with a circulating air return duct 2041a for removing circulating air from the dryer tunnel 2005 and a circulating air supply duct 2041b for introducing circulating air into the dryer tunnel 2005 is.

In the plant 2001 there are devices 2043 for supplying additional fresh air into the receiving areas of the drying tunnel 2005. The devices 2043 have lines 2045 which communicate with a receiving area in the drying tunnel 2005 and which contain a flow control device 2047 designed as a throttle valve.

It should be noted that the flow control device 2047 can alternatively or additionally also be equipped with a fan. Fresh air is fed into the circulating air line system 2041 of the devices 2031, 2033, 2035 via the lines 2045 if the fresh air supplied through the nozzles 2014 to the dryer tunnel 2005 is not sufficient to cover the fresh air requirement within the dryer tunnel.

The system 2001 contains a control device 2046. The control device 2046 is connected to a first device 2051 for detecting a status parameter of the dryer tunnel 2005 acting as a process chamber in the system 2001. In the device 2051, a setting of the throttle flaps 2052, 2055 in the lines 2038 for conducting hot gas through the heat exchanger 2039 and a setting of the throttle flaps 2047 in the lines 2045 for the supply of fresh air are detected by means of potentiometers or limit switches. From this, a quantity of fluid supplied to the dryer tunnel 2005 per unit of time using the devices 2031, 2033, 2035 and 2037 can be determined. In this way, an amount of heat supplied with the fluid can optionally be determined if temperature sensors assigned to the lines of a circulating air line system 2041 and a line 2045 measure the fluid temperatures be measured.

In addition, the control device 2046 is connected to a second device 2053 for detecting a status parameter of the dryer tunnel 2005 acting as a process chamber in the plant 2001. The device 2053 is designed as a body counting device with which the number of motor vehicle bodies 2003 moved into the drying tunnel 2005 per unit of time and thus the quantity of motor vehicle bodies 2003 arranged in the drying tunnel 2005 can be determined.

The control device 2046 is also connected to a temperature sensor 2007 for detecting the hot gas temperature T _A in the hot gas line 2036 . The temperature sensor 2007 is used to measure the temperature of the hot gas flowing through the hot gas line 2036 on the outlet side of the heat transfer device 2037, with which the hot gas from the system 2001 is released as clean gas to the environment (clean gas above the roof temperature).

The control circuit 2046 is connected to a control module 2056 for adjusting the speed of a fan 2057 arranged in the line 2025 and another control module 2059 for adjusting the speed of a fan 2061 which is used for drawing fresh air into the line 2019 to the one fluid flow curtain 2021 generating nozzles 2009 in the dryer tunnel 2005 is used.

The flow control devices 2047 in the devices 2043 for the supply of fresh air and the speed of the fan 2057 are then controlled by the control circuit 2046 depending on the value determined by the device 2051 for the quantity of heat supplied to the dryer tunnel 2005 per unit of time and the number determined by the device 2053 of bodies 2003 placed in the interior of the drying tunnel 2005.

By means of the fan 2061, enough fresh air is always fed into the line 2019 that the locks 2011, 2012 and 2013 are sealed off by means of the fluid flow curtain 2021 generated with the nozzles 2009.

• Lösemitteleintrag in die Atmosphäre in den Aufnahmebereichen des Trocknertunnels 2005;
• Gesamtkohlenstoffgehalt in den Aufnahmebereichen des Trocknertunnels 2005;
• Anzahl der in den Aufnahmebereichen des Trocknertunnels angeordneten Karossen;
• Temperatur des mit der Heizeinrichtung 2023 erzeugten Heißgases in der Heißgasleitung 2036 hinter der Einrichtung 2037 vor einem Abluftkamin;
• Temperaturunterschied der Umluft vor und nach den Einrichtungen 2031, 2033 und 2035;
• Temperaturunterschied von Abluft aus dem Trocknertunnel, die einer Abgasreinigungsanlage zugeführt wird, und von Abluft, welche die Abgasreinigungsanlage durch einen Abluftkamin verlässt;
• Gewicht einer Karosse oder Größe einer mit Lack beaufschlagten Karossenoberfläche, um daraus auf eine Lösemittelmenge zu schließen.

It should be noted that the control device 2046 can in principle also be designed as a control circuit. In addition, it should be noted that the fresh air supply through the heat transfer devices 2031, 2033, 2035 in the dryer tunnel 2005 can also be controlled or regulated with a control device 2046, one or more of the measured variables specified below as process chamber operating condition parameters for the system 2001 are supplied:

• solvent entry into the atmosphere in the receiving areas of the drying tunnel 2005;
• Total carbon content in the receiving areas of the drying tunnel 2005;
• number of car bodies arranged in the receiving areas of the drying tunnel;
• Temperature of the hot gas generated with the heating device 2023 in the hot gas line 2036 behind the device 2037 in front of an exhaust chimney;
• temperature difference of the circulating air before and after the devices 2031, 2033 and 2035;
• Temperature difference of exhaust air from the drying tunnel, which is fed to an exhaust gas cleaning system, and exhaust air, which leaves the exhaust gas cleaning system through an exhaust air chimney;
• Weight of a body or size of a body surface that has been coated with paint, in order to determine the amount of solvent.

It is advantageous if a plurality of measured variables are combined as state parameters (process chamber operating state parameters) in the control device 2046 . So e.g. B. also a clean gas above the roof temperature detected by the temperature sensor 2007 as a primary measured variable and a setting of the throttle flaps 2052, 2055 for setting the hot gas flow in the hot gas lines 2036, 2038 (clean gas flap position) as a secondary measured variable . The primary measured variable is used to determine a fresh air/exhaust air volume flow and the secondary measured variable is used to check, confirm and/or correct this fresh air/exhaust air volume flow if necessary.

After determining the fresh air exhaust air volume flow via the clean gas above the roof temperature then z. B. a review of this current based on the secondary measured variable. For example, the variable fresh air volume flow is kept constant or increased until the positions of all clean gas flap positions are again below a previously specified value, if the position of the clean gas flap positions exceeds said specified value, which depends on the overall system and is between 50 % and 100% degree of opening. With such a combination of several measured variables, it can be ensured in particular that the drying tunnel 2005 of the plant 2001 contains a sufficient amount of heat.

In particular, the system 2001 can be operated as follows:
In a first operating mode, which corresponds to a utilization state A of the system 2001 of, for example, A ≤ 50% based on the maximum possible capacity of workpieces in the process chamber designed as a drying tunnel, a constant fresh air volume flow is provided via the locks 2011, 2012 and/or supplied in 2013. An additional supply of fresh air via the lines 2045 into the process chamber does not necessarily have to take place here.

In a second operating mode, which corresponds to a utilization level A of the system 2001 of, for example, 51% ≤ A ≤ 90% based on the maximum possible capacity of workpieces in the process chamber designed as a drying tunnel, a constant fresh air volume flow is via the locks 2011, 2012 and/or added in 2013. At the same time, additional fresh air is introduced into the process chamber via the heat exchanger devices 2031, 2033, 2035 and/or 2037 by opening flow control devices 2047 designed as throttle flaps in the lines 2045.

In a third operating mode, which corresponds to a capacity utilization of the system 2001 of, for example, 91% ≤ A ≤ 100% based on the maximum possible capacity of workpieces in the process chamber designed as a drying tunnel, a constant fresh air volume flow is provided via the locks 2011, 2012 and /or 2013 supplied, and the flow of additional fresh air supplied in the heat transfer devices 2013, 2033, 2035 and/or 2037 is further increased by additional opening of the flow control devices 2047 in relation to the second operating mode.

It should be noted that the system 2001 can also be operated in other operating modes in which the flow control devices 2047 in the lines 2045 have a different opening position in relation to the aforementioned operating modes. In particular, a stepless change in the operating mode of the system 2001 is also possible in principle.

In particular, it should be noted that the feeding of fresh air into the dryer tunnel 2005 in the plant 2001 can also take place at other points than in FIG 11 are shown:
In an alternative embodiment of the plant 2001 z. B. be provided that in the receiving areas 2015a, 2015b, 2016 of the dryer tunnel 2005 circulating air and / or fresh air is supplied via openings in the wall, in the ceiling and / or in the floor of the dryer tunnel 2005. Fresh air can be fed into the circulating air line system 2041 in a system 2001 described above, also in relation to the flow direction of the circulating air, in principle before or after a heat exchanger 2039 in a heat transfer device 2031, 2033, 2035. It should also be noted that fresh air can be fed both inside a heat transfer device 2031, 2033, 2035 and outside a heat transfer device 2031, 2033, 2035 into a circulating air return duct 2041a or circulating air return duct of a circulating air line system 2041.

In order to set a defined volume flow for the fresh air, a fan can also be arranged in the line 2045 for fresh air. In addition, it is possible for the fresh air to be supplied to the system 2001 in a lock 2011 , 2013 , 2015 on the side of a fluid flow curtain 2021 pointing into the interior of the dryer tunnel 2005 .

To explain the alternative versions of the system 2001 listed above, the following are based on the Figures 12 to 19 further drying systems according to the invention are described:
The 12 shows a further system 2001 'for drying vehicle bodies 2003, the structure of the system 2001 from 11 basically corresponds. As far as the assemblies in the 2001 system 11 and in Annex 2001' 12 are identical, these have in the 11 and the 12 the same reference numbers. In the system 2001', the line 2045 for supplying fresh air to the circulating air line system 2041 is connected via a line branch 2045a and a line branch 2045b in the heat transfer device 2037 to the line 2019 for supplying fresh air to the nozzles 2009. Through the line branch 2045a, it is possible to feed fresh air sucked in by the fan 2061 into the line 2045, which was heated in the heat exchanger 2039 of the heat transfer device 2031 with heat from the clean gas conducted in the hot gas line 2036.

Alternatively or additionally, fresh air can also be conveyed through the line branch 2045b in the heat transfer device 2037 into the line 2019 by means of the fan 2061 into the line 2045 . In this case, the fresh air conveyed by means of the fan 2061 is then not or only partially guided through the heat exchanger 2039 in the heat transfer device 2037 .

The fresh air carried in the line 2019 is introduced into the heat transfer devices 2031, 2033 and 2035 in the system 2001' in such a way that it reaches the dryer tunnel 2005 via the heat exchanger arranged in the heat transfer devices 2031, 2033 and 2035.

The fresh air from line 2045 introduced into the heat transfer devices 2031, 2033 and 2035 can thus be heated with heat from the clean gas conducted in the hot gas line 2036.

A flow measuring device 2062 is arranged in the line section 2019a of the system 2001'. The flow measuring device 2062 controls an actuator in a flow control device 2048. This ensures in the system 2001' that for different speeds of the fan 2061 the nozzles 2009, 2014 for generating a fluid flow curtain 2020, 2021 are supplied with a constant flow of fresh air. A flow measuring device 2063 is arranged in the line 2045 . The flow meter 2063 is used for that Determining the amount of fresh air fed into line 2045 by fan 2061 .

In the system 2001 ′, the fresh air flow fed into the line 2045 via the throughflow control device 2048 is adjusted as a function of the number of bodies 2003 arranged inside the drying tunnel 2005 determined by the device 2053 .

The flow measuring devices 2062, 2063 determine the quantity of fresh air fed into the line 2019, 2045 by means of the fan 2061 by detecting the pressure drop at an orifice plate arranged in the line section with the flow measuring device 2062, 2063. It should be noted that the flow measuring device 2062, 2063 for detecting the flow of fresh air can alternatively contain a magnetically inductive sensor, an ultrasonic measuring unit or an impeller.

The 13 shows another system 2001 "for drying, the structure of which is essentially identical to the structure of the system 2001' described above 12 and the 13 systems shown are functionally the same, these have in 12 and 13 the same numbers as references.

Unlike in the system 2001' 12 the fresh air is fed into the system 2001" through the line 2045 for the supply of fresh air in the heat transfer devices 2031, 2033 and 2035 on the outlet side of the heat exchanger 2039 into the circulating air line system 2041. In a heat exchanger 2039 of a heat transfer device 2031, 2033, 2035 then only the circulating air supplied through a supply channel 2041a from the dryer tunnel 2005 is heated.

The 14 and 15 show further systems 2001"' and 2001"" for drying, the construction of which is based on the 12 and 13 corresponds to the system described. Functionally identical assemblies in these systems have the same reference numbers as the corresponding assemblies of the systems 12 and 13 . In the system 2001"', fresh air is introduced via the line 2045 outside the heat transfer devices 2031, 2033 and 2035 into the circulating air return channel 2041b of the line system. In the system 2001"", the line 2045 for supplying fresh air into the dryer tunnel 2005 is also a circulating air return duct 2041a of the line system 2041, through which the circulating air from the dryer tunnel 2005 is guided into a heat transfer device 2031, 2033 and 2035.

It should be noted that in a modified embodiment of the system 2001"" from 14 or 2001"" off 15 provision can also be made to feed fresh air from a line 2045 both into a circulating air return duct 2041a and into a circulating air return duct 2041b of a circulating air line system 2041 . However, if the fresh air is fed into a recirculation air return duct 2041, it must be ensured that the fresh air in question is heated.

The one in the 16 The system 3001 shown for drying vehicle bodies 3003 has several temperature sensors 3070, 3072, 3074 and 3076 as a device for detecting a status parameter of a drying tunnel 3005 acting as a process chamber 11 functionally correspond, these are in the 12 with regarding the 11 Numbers increased by the number 1000 are identified as reference symbols.

The temperature sensors 3070, 3072, 3074 and 3076 are connected to the controller 3046. The temperature sensor 3070 is arranged in the hot gas line 3026 between the heating device 3023 and the heat transfer device 3031 . The temperature sensor 3072 is located in an end section of the hot gas line 3026, from which the clean gas flowing through the hot gas line 3026 reaches the ambient atmosphere. The temperature sensors 3070, 3072 are used to determine the heat given off by the clean gas flowing through the hot gas line 3026 into the dryer tunnel 3005 by determining the difference between the temperatures ΔT _H =T ₁ -T ₂ measured by means of these temperature sensors. The temperature sensors 3074 and 3076 are used to determine the difference in the temperatures ΔT _U :=T ₃ -T ₄ of circulating air flowing out of the dryer tunnel 3005 in the circulating air return duct 3041a and circulating air mixed with fresh air, which is conducted through the circulating air supply duct 3041b into the dryer tunnel 3005.

The control device 3046 controls the speed of the fan 3057 in the line 3025 and the setting of the flow control devices 3047 for setting the amount of fresh air fed into the line system 3041 as a function of the temperature difference ΔT _H , ΔT detected by the temperature sensors 3070, 3072, 3074 and 3076 _U. As an alternative to this, the control device 3046 can also be designed as a control loop which controls the speed of the fan 3057 in the line 3025 and the setting of the flow control device 3047 on the basis of the signal from the temperature sensors 3070, 3072, 3074 and 3076.

The one in the 17 The system 4001 shown for drying vehicle bodies 4003 has a scale 4078 for determining the mass of the vehicle bodies 4003 fed into the dryer tunnel 4005 as a device for detecting a status parameter of a dryer tunnel 4005 acting as a process chamber 2001 out 11 functionally correspond, these are in the 13 with regarding the 11 Numbers increased by the number 2000 are identified as reference numbers.

Here the control device 4046 controls the speed of the fan 4057 in the line 4025 and the setting of the flow control devices 4047 for setting the amount fed into the line system 4041 Fresh air depending on the mass of the vehicle bodies 4003 fed into the dryer tunnel 4005, which is recorded by means of the scales 4078.

Further modifications and developments of a system according to the invention can result, inter alia, from a combination of different features of the advantageous exemplary embodiments described above.

In summary, the following features of the invention can be noted, among others: A process chamber 5, 2005 has an interior 39 with a receiving area 15, 2015a, 2015b, 2016 for workpieces 3, 2003. The process chamber 5, 2005 has an opening 12, 14, 2015 , 2017 for the supply or removal of workpieces 3, 2003. The process chamber 5, 2005 is designed with a device 17, 19, 25, 29, 33, 37, 35, 2014 for blowing gaseous fluid into the interior 39, which has at least one nozzle 17, 19, 2014 or screen 803 for generating a fluid flow curtain 21, 23, 2021 between the opening 12, 14, 2015, 2017 and the receiving area 15, 2015a, 2015b for workpieces 3, 2003. The process chamber 5, 2005 has a device 74, 2043 for supplying fresh air, with fresh air being introduced into the receiving area 15, 2015a, 2015b on the side of the fluid flow curtain 21, 23, 2021 facing away from the opening 12, 14, 2015, 2017 can be.

Reference list:

1

Attachment

3

vehicle body

5

Dryer tunnel, process chamber

6

Ceiling

7

skid

9

conveyor

10

drive

11

entry lock

12

inlet opening

13

exit lock

14

outlet opening

15

drying section, drying zone

16, 18

diffuser

17, 19

jet

17, 19, 25, 29, 33, 37, 35

contraption

21, 23

fluid flow curtain

25, 27

fresh air

29, 31

chamber

33, 35

opening

37

horizontal

39

inner space

41

Floor

42

ambient air

43, 44

heating device

45, 47

control device

49, 51

sensor

61

fan

74, 74'

Furnishings

63

heating device

69.71

temperature sensor

70

Furnishings

72

recirculation system

73

solvent sensor

74

Furnishings

75

flow channel

76, 76'

Management

77

return channel

78, 78'

opening

80, 80'

flow control device

201

pipeline

202

main flow plane

203

chamber

204

level

205

air filter

206

housing sheet metal

207

baffle

208

axis of rotation

209

opening

210

fluid flow

211

Guide contour, contour, guide plate

213

entrance opening

215

end wall, end plate

216

side chamber

217

mixing chamber

219

Fluid

401

fluid flow curtain

402

Arrow

403

club

406

Arrow

407

flow roll

408

Arrow

409

center

501

sluice, entrance sluice

503

jet

505

nozzle opening

507

nozzle opening

509

Ceiling

507, 509

nozzle openings

511

control flap

601

sluice

603

jet

605

baffle

607

orifice, nozzle

608

Ceiling

609

end wall

611

the inner

612

ridge element

613

mixing chamber

615

swivel joint

616

horizontal

617

double arrow

619

opening

701

sluice

703

jet

704

flow channel

709

end wall

711

the inner

713

mixing chamber

721

Area

801

sluice

803

cover

804

opening

805

baffle

809

end wall

812

ridge element

816

recess

821

Area

900

drying tunnels

901

sluice, exit sluice

903, 905, 907

jet

909

fresh airflow

910

Ceiling

911, 913, 915

channel

917

fluid flow curtain

1006

Ceiling

1009

opening

1011

sluice, entrance sluice

1017

jet

1039

inner space

1041

Floor

1209

opening

1210

diffuser

1211

baffle

1213

opening, entrance opening

1215

ridge wall

1216

side chamber

1217

mixing chamber

1218

Flow guide element, flow vane

1220

silhouette wall, arrow

1222

axis

1224

Arrow

1401

fluid flow curtain

1402

Arrow

1403

club

1406

Arrow

1407

flow roll

1408

Arrow

1409

center, center of rotation

2001, 2001' 2001", 2001'", 2001""

Attachment

2003

Vehicle body, workpiece

2005

Dryer tunnel, process chamber

2007

temperature sensor

2009

jet

2011, 2012, 2013, 2015

sluice

2014

jet

2015a, 2015b

drying section, receiving area

2015, 2017

opening

2016

holding zone

2018

diffuser

2019

Management

2019a

line section

2020

fluid flow curtain

2021

fluid flow curtain

2023

heating device

2025

Management

2027

heat exchanger

2029

combustion chamber

2031, 2033, 2035

heat transfer device

2036, 2038

hot gas line

2037

heat transfer device

2039

heat exchanger

2041

recirculation system

2041a

circulating air return duct

2041b

circulating air supply duct

2043

Furnishings

2045

Management

2045a, 2045b

line branch

2046

control device

2047, 2048

flow control device

2049

control circuit

2051, 2053

Furnishings

2052, 2055

throttle

2056, 2059

control module

2057, 2061

fan

2062, 2063

flow meter

3001

Attachment

3003

Vehicle body, workpiece

3005

Dryer tunnel, process chamber

3023

heating device

3025, 3045

Management

3026

hot gas line

3031

heat transfer device

3041

piping system

3041a

circulating air return duct

3041b

circulating air supply duct

3046

control device

3047

throttle bodies

3057

fan

3070, 3072, 3074 and 3076

temperature sensor

4001

Attachment

4003

Vehicle body, workpiece

4005

Dryer tunnel, process chamber

4025, 4045

Management

4041

piping system

4046

control device

4047

throttle

4057

fan

4078

Scale

Claims (18)

1. Installation (1, 2001) having a process chamber (5, 2005) which comprises an interior (39) having a receiving region (15, 2015a, 2015b, 2016) for workpieces (3, 2003) and which has an opening (12, 14, 2015, 2017) for supplying or removing workpieces (3, 2003); and

   having a device (17, 19, 25, 29, 33, 37, 35, 2014) for blowing gaseous fluid into the interior (39), which device has at least one nozzle (17, 19, 2014) or mouth (803) for generating a fluid flow curtain (21, 23, 2021) between the opening (12, 14, 2015, 2017) and the receiving region (15, 2015a, 2015b) for workpieces (3, 2003),

   having an apparatus (70, 2031, 2033, 2035) for circulating gaseous fluid in the receiving region (15, 2015a, 2015b) by means of a circulating air line system (72, 2041) which communicates with the receiving region (15, 2015a, 2015b) and has a feed channel (75) which opens into the receiving region (15) and a return channel (77) which is connected to the receiving region and in which the circulated gaseous fluid is guided through an apparatus (2031, 2033) for controlling the temperature, in particular for heating gaseous fluid from the receiving region (15, 2015a, 2015b),

   characterized in that

   the apparatus (70, 2031, 2033, 2035) for circulating gaseous fluid in the receiving region (15, 2015a, 2015b) is connected to an apparatus (74, 2043) for supplying fresh air,

   by means of which apparatus fresh air can be introduced into the receiving region (15, 2015a, 2015b) at a side of the fluid flow curtain (21, 23, 2021) facing away from the opening (12, 14, 2015, 2017) and which apparatus contains at least one line (78, 2045) for supplying fresh air, which communicates with the receiving region (15, 2015a, 2015b) and has an opening for sucking in fresh air and has a flow control apparatus (80, 2047),

   a mixing chamber (217) being provided which is arranged adjacently to the nozzle (17, 19) and is used for mixing air from the region of the opening (213) or the interior (39) of the process chamber (5) to form gaseous fluid flowing out of the at least one nozzle (17, 19) or mouth.
2. Installation according to claim 1, characterized in that the line (76) having the opening (78) for sucking fresh air into a circulating air return channel (77) opens into the circulating air line system (72).
3. Installation (1, 2001) having a process chamber (5, 2005) which comprises an interior (39) having a receiving region (15, 2015a, 2015b, 2016) for workpieces (3, 2003) and which has an opening (12, 14, 2015, 2017) for supplying or removing workpieces (3, 2003); and

   having a device (17, 19, 25, 29, 33, 37, 35, 2014) for blowing gaseous fluid into the interior (39), which device has at least one nozzle (17, 19, 2014) or mouth (803) for generating a fluid flow curtain (21, 23, 2021) between the opening (12, 14, 2015, 2017) and the receiving region (15, 2015a, 2015b) for workpieces (3, 2003),

   having an apparatus (70, 2031, 2033, 2035) for circulating gaseous fluid in the receiving region (15, 2015a, 2015b) by means of a circulating air line system (72, 2041) which communicates with the receiving region (15, 2015a, 2015b) and has a feed channel (75) which opens into the receiving region (15) and a return channel (77) which is connected to the receiving region and in which the circulated gaseous fluid is guided through an apparatus (2031, 2033) for controlling the temperature, in particular for heating gaseous fluid from the receiving region (15, 2015a, 2015b),

   characterized in that

   the apparatus (70, 2031, 2033, 2035) for circulating gaseous fluid in the receiving region (15, 2015a, 2015b) is connected to an apparatus (74, 2043) for supplying fresh air,

   by means of which apparatus fresh air can be introduced into the receiving region (15, 2015a, 2015b) at a side of the fluid flow curtain (21, 23, 2021) facing away from the opening (12, 14, 2015, 2017) and which apparatus contains at least one line (76, 2045) for supplying fresh air, which communicates with the receiving region (15, 2015a, 2015b) and has an opening for sucking in fresh air and has a flow control apparatus (80, 2047), a fan (2061) for adjusting a defined volume flow of the supplied fresh air being arranged in the line (76, 2045) which communicates with the receiving region (15, 2015a, 2015b), a heat exchanger (2039), which is designed as an air-air heat exchanger, for heating the fresh air sucked in by means of the fan (2061) with heat from a heating apparatus (2023) being arranged in a heat-transfer apparatus (2037) in the line (78, 2045) which communicates with the receiving region (15, 2015a, 2015b), the heating apparatus (2023) being designed as an apparatus for cleaning thermal exhaust air, a line (2025) for supplying exhaust air from the process chamber (5, 2005) to the heating apparatus (2023) being provided and a heat exchanger (2027) which is used for heating up the exhaust air supplied to the heating apparatus (2023) being provided and the line (78, 2045) which communicates with the receiving region (15, 2015a, 2015b) being joined to a line (2019) for supplying fresh air to the at least one nozzle (17, 19, 2014) or mouth (803) for generating a fluid flow curtain (21, 23, 2021) from fresh air at a side of the heat exchanger (2039) facing away from the opening for sucking in fresh air, the at least one line (76, 2045) which communicates with the receiving region (15, 2015a, 2015b) for supplying fresh air being connected with the line (2019) for supplying fresh air to the at least one nozzle (17, 19, 2014) or mouth (803) for generating a fluid flow curtain (21, 23, 2021) from fresh air via a first line branch (2045a) in the heat-transfer apparatus (2037) at a side of the heat exchanger (2039) facing away from the opening for sucking in fresh air and via a second line branch (2045b) in the heat-transfer apparatus (2037) at a side of the heat exchanger (2039) facing the opening for sucking in fresh air, and the line (76) which communicates with the receiving region (15, 2015a, 2015b) opening into a circulating air return channel (77) in the circulating air line system (72, 2041) at the opening (78) for sucking in fresh air.
4. Installation according to claim 3, characterized in that the flow control apparatus (80, 2047) is connected to an open-loop or closed-loop control circuit (45, 2049) which receives the signal of an apparatus (49, 69, 73, 2051) for detecting a state parameter of the process chamber (5, 2005) and which controls the quantity of fresh air introduced into the receiving region (15) via the apparatus for supplying fresh air in an open-loop or closed-loop manner by means of the flow control apparatus (80, 2047) depending on at least one detected state parameter.
5. Installation according to claim 4, characterized in that the apparatus (2051) is designed for detecting a state parameter of the process chamber (5, 2005) from the group specified below:

   i. the carbon content and/or solvent content of the atmosphere in the receiving region (2015a, 2015b, 2016);

   ii. the number and/or weight and/or type and/or size of the surface of workpieces (2003) arranged in the receiving region;

   iii. the number and/or weight and/or type and/or size of the surface of workpieces (2003) supplied to the receiving region per unit of time;

   iv. the temperature of the exhaust air from the combustion chamber (2029) of a burner in an apparatus for controlling the temperature of circulating air;

   v. the temperature difference between gaseous fluid which is taken from the receiving region (2015a) and which is supplied back to the receiving region (2015a);

   vi. the temperature difference between gaseous fluid from the receiving region (2015a), which is supplied to a combustion chamber (2029) of a burner in an apparatus for controlling the temperature of circulating air, and exhaust air from the combustion chamber (2029) of the burner,

   vii. the amount of heat per unit of time which is supplied to the process chamber (2005).
6. Installation according to any of claims 1 to 5, characterized in that the interior (39) is tunnel-shaped and has a bottom (41) and a ceiling (6), the at least one nozzle (17, 19) or mouth (803) having a slot shape which supplies the gaseous fluid via the ceiling (6) with a flow direction (402) inclined with respect to the floor (41) into the interior (39), and the gaseous fluid supplied into the interior (39) generates a flow vortex (407) of air at the side of the fluid flow curtain (21, 23) facing the opening (12, 14), which flow vortex is at least partially mixed with the fluid blow in.
7. Installation according to claim 6, characterized in that the gaseous fluid supplied into the interior (39) is fresh air.
8. Installation according to either claim 6 or claim 7, characterized in that the gaseous fluid which is blown into the interior (39) via the at least one nozzle (17, 19) or mouth (803) is guided through a diffuser (16, 2018) into the interior (39), the gaseous fluid which is blown into the interior (39) through the diffuser (16, 2018) being guided on a guide contour (606) into the interior (39).
9. Installation according to claim 8, characterized in that the line contour (606) is formed on a pivotable guide vane (605).
10. Installation according to either claim 8 or claim 9, characterized in that a wall (215, 1215) is arranged on the side of the guide contour (211, 1211) facing the opening (213, 1213), which wall defines a diffuser (16, 18) having a mixing chamber (217, 1217) together with the guide contour (211, 1211), in which mixing chamber fluid from the flow vortex (407, 1407) is mixed with air from the region of the opening (213, 1213).
11. Installation according to claim 10, characterized in that a secondary chamber (216) acting as a dead space for gaseous fluid is formed at a side of the guide contour (211) facing away from the mixing chamber (217), and/or
    in that a guide vane (1218) is arranged in the mixing chamber (1217), which guide vane is flowed against with gaseous fluid from the flow vortex (1407) and which recirculates the fluid from the flow vortex (1407) into the fluid flow curtain (1401).
12. Installation according to claim 6, characterized in that the flow control apparatus comprises a throttle valve (80, 2047) and/or an adjustable blower, and/or

    in that the receiving region is divided into a first receiving region (2015a) and a further receiving region (2015b), and the device (2014) for blowing gaseous fluid into the interior generates the fluid flow curtain (2021) between the first receiving region (2015a) and the further receiving region (2015b), and/or

    in that the at least one nozzle (503) has an apparatus (511) for adjusting the flow rate for fluid passing through the nozzle (503) and/or in that a plurality of nozzles (903, 905, 907) are provided with an apparatus for adjusting the flow rate for fluid passing through the nozzle in order to adjust the fluid flow curtain differently between the inlet opening and the receiving region for workpieces (912) in different portions, and/or

    in that a pivotable flow barrier (1220) is provided for controlling a fluid flow formed in the interior (1039), and/or

    in that the device for blowing gaseous fluid has a heating apparatus (43, 44) for heating the gaseous fluid, and/or

    in that the installation is designed as a drying and/or curing installation and/or painting installation.
13. Installation (1, 2001) having a process chamber (5, 2005) which comprises an interior (39) having a receiving region (15, 2015a, 2015b, 2016) for workpieces (3, 2003) and which has an opening (12, 14, 2015, 2017) for supplying or removing workpieces (3, 2003); and

    having a device (17, 19, 25, 29, 33, 37, 35, 2014) for blowing gaseous fluid into the interior (39), which device has at least one nozzle (17, 19, 2014) or mouth (803) for generating a fluid flow curtain (21, 23, 2021) between the opening (12, 14, 2015, 2017) and the receiving region (15, 2015a, 2015b) for workpieces (3, 2003),

    having an apparatus (70, 2031, 2033, 2035) for circulating gaseous fluid in the receiving region (15, 2015a, 2015b) by means of a circulating air line system (72, 2041) which communicates with the receiving region (15, 2015a, 2015b) and has a feed channel (75) which opens into the receiving region (15) and a return channel (77) which is connected to the receiving region and in which the circulated gaseous fluid is guided through an apparatus (2031, 2033) for controlling the temperature, in particular for heating gaseous fluid from the receiving region (15, 2015a, 2015b),

    characterized in that

    the apparatus (70, 2031, 2033, 2035) for circulating gaseous fluid in the receiving region (15, 2015a, 2015b) is connected to an apparatus (74, 2043) for supplying fresh air,

    by means of which apparatus fresh air can be introduced into the receiving region (15, 2015a, 2015b) at a side of the fluid flow curtain (21, 23, 2021) facing away from the opening (12, 14, 2015, 2017) and which apparatus contains at least one line (78, 2045) for supplying fresh air, which communicates with the receiving region (15, 2015a, 2015b) and has an opening for sucking in fresh air and has a flow control apparatus (80, 2047),

    means for changing the direction of the fluid flow curtain (21, 23) being provided when a workpiece (3) is moved through the opening (12, 14).
14. Installation (1, 2001) having a process chamber (5, 2005) which comprises an interior (39) having a receiving region (15, 2015a, 2015b, 2016) for workpieces (3, 2003) and which has an opening (12, 14, 2015, 2017) for supplying or removing workpieces (3, 2003); and

    having a device (17, 19, 25, 29, 33, 37, 35, 2014) for blowing gaseous fluid into the interior (39), which device has at least one nozzle (17, 19, 2014) or mouth (803) for generating a fluid flow curtain (21, 23, 2021) between the opening (12, 14, 2015, 2017) and the receiving region (15, 2015a, 2015b) for workpieces (3, 2003),

    having an apparatus (70, 2031, 2033, 2035) for circulating gaseous fluid in the receiving region (15, 2015a, 2015b) by means of a circulating air line system (72, 2041) which communicates with the receiving region (15, 2015a, 2015b) and has a feed channel (75) which opens into the receiving region (15) and a return channel (77) which is connected to the receiving region and in which the circulated gaseous fluid is guided through an apparatus (2031, 2033) for controlling the temperature, in particular for heating gaseous fluid from the receiving region (15, 2015a, 2015b),

    characterized in that

    the apparatus (70, 2031, 2033, 2035) for circulating gaseous fluid in the receiving region (15, 2015a, 2015b) is connected to an apparatus (74, 2043) for supplying fresh air,

    by means of which apparatus fresh air can be introduced into the receiving region (15, 2015a, 2015b) at a side of the fluid flow curtain (21, 23, 2021) facing away from the opening (12, 14, 2015, 2017) and which apparatus contains at least one line (78, 2045) for supplying fresh air, which communicates with the receiving region (15, 2015a, 2015b) and has an opening for sucking in fresh air and has a flow control apparatus (80, 2047),

    means for changing the direction of the fluid flow curtain (21, 23) being provided when a workpiece (3) is moved through the opening (12, 14),

    means in the form of a fan (2061) acting as a compressor for guiding pressurized gaseous fluid through the nozzle (17, 19) or mouth (803) being provided for generating the fluid flow curtain (21, 23, 2021), and

    a mixing chamber (217) being provided, which is adjacent to the nozzle (17, 19) and in which air from the region of the opening (213) or the interior (39) of the process chamber (5) can be mixed with the gaseous fluid flowing out of the nozzle (17, 19).
15. Method for operating an installation according to any of claims 1 to 12, in which gaseous fluid which is pressurized for generating the fluid flow curtain (21, 23, 2021) is guided through the nozzle (17, 19) or mouth (803) and in which air from the region of the opening (213) or the interior (39) of the process chamber (5) is mixed with the gaseous fluid flowing out of the nozzle (17, 19) in the mixing chamber (217) adjacent to the nozzle (17, 19).
16. Method according to claim 15, characterized in that the gaseous fluid guided through the nozzle (17, 19) is guided along a guide contour (211) which delimits the mixing chamber (217) and separates in particular the mixing chamber (217) from a secondary chamber (216) acting adjacently to this as a dead space for gaseous fluid.
17. Method for operating a system according to either claim 15 or claim 16, in which a flow of gaseous fluid guided through the nozzle (17, 19) or mouth (803) for generating a fluid flow curtain (21, 23) between the opening (12, 14) and the receiving region (15) for workpieces (3) is throttled or interrupted and/or in which the direction of the fluid flow curtain (21, 23) is changed when a workpiece (3) is moved through the opening (12, 14).
18. Method according to any of claims 15 to 17, in which the fluid flow curtain (21, 23, 2021) is generated with a constant fresh air quantity on average over a period of time, said fresh air quantity being guided through the nozzle (17, 19) or the mouth (803), and in which a variable fresh air quantity is supplied to the apparatus (74, 2043) for supplying fresh air into the interior (39) in the period of time, said fresh air quantity being controlled in an open-loop or closed-loop manner depending on a process chamber operating state parameter from the group specified below:

    i. the carbon content and/or solvent content of the atmosphere in the receiving region (2015a, 2015b, 2016);

    ii. the number and/or weight of workpieces (2003) arranged in the receiving region;

    iii. the number and/or weight of workpieces (2003) supplied to the receiving region per unit of time;

    iv. the temperature of the exhaust air from the combustion chamber (2029) of a burner in an apparatus for controlling the temperature of circulating air;

    v. the temperature difference between gaseous fluid which is taken from the receiving region (2015a) and which is supplied back to the receiving region (2015a);

    vi. the temperature difference between gaseous fluid from the receiving region (2015a), which is supplied to a combustion chamber (2029) of a burner in an apparatus for controlling the temperature of circulating air, and exhaust air from the combustion chamber (2029) of the burner,

    vii. the amount of heat per unit of time which is supplied to the process chamber (2005).

Images