Patent Application
20180238622
The invention relates to an installation having a process chamber which has an inner space having a receiving region for workpieces and which has a portal for the supply or discharge of workpieces and which has a device for the introduction of gaseous fluid into the inner space, which device comprises at least one nozzle or aperture for the production of a fluid stream curtain between the portal and the receiving region for workpieces.
An installation of this type is known from DE 24 54 091 A1. The installation has a process chamber with an inlet portal and an outlet portal, in which there is in each case one fluid stream curtain. The fluid stream curtain is in this case composed partially of fresh air, which can pass into the interior of the process chamber.
WO 2010/122121 A1 describes an installation for drying workpieces, which installation has a process chamber for controlling the temperature of workpieces, which process chamber is closed by means of a fluid stream curtain at an inlet portal and at an outlet portal. The process chamber is in this case likewise fed with the fresh air from the fluid stream curtain.
GB 2 123 936 A describes an installation for drying workpieces in a process chamber, which receives fresh air by means of a fluid stream curtain of the inlet portal and outlet portal.
U.S. Pat. No. 1,606,442 A has disclosed an installation for drying vehicle bodies, which installation has a process chamber which is separated from the surroundings by means of a fluid curtain. The vehicle bodies that are dried in the process chamber in the installation are moved through the fluid stream curtain as they exit the installation. To produce the fluid stream curtain, the installation has an aperture or nozzle with a slot-shaped opening which extends over the entire width of the process chamber.
U.S. Pat. No. 3,947,235 describes a process chamber and a method for drying freshly painted vehicle bodies, wherein a fluid stream curtain is produced between portals for the supply and discharge of the motor vehicle bodies into and out of the process chamber and a receiving region for the vehicle bodies in the process chamber.
In production units for painting and coating vehicle bodyworks, drying installations are used for drying vehicle bodyworks which have been freshly painted or coated with corrosion protection. Those installations have a process chamber which is in the form of a drying tunnel and into which hot air is blown. There is a drying zone in the drying tunnel. The drying zone is a receiving region for workpieces in the form of vehicle bodyworks. In order to dry the vehicle bodyworks, they are moved on a conveying device through the drying tunnel. The coat of paint or coating of the vehicle bodyworks to be dried may be impaired by impurities, in particular particles of dust. Furthermore, gaseous fluid and with it heat from the inner space may be discharged through a portal for the supply of workpieces.
An object of the invention is to provide an installation having a process chamber which has an inner space which has a receiving region for workpieces and which can be opened at least partially, in which installation an efficient thermal separation of that inner space from the environment is possible with simple means and, at the same time, an adequate fresh air supply for the receiving region can be ensured.
The installation has a process chamber which includes: an inner space defining a tunnel-shaped receiving region for workpieces; the receiving region having a ceiling and a floor; a portal for supplying or discharging workpieces; a blowing arrangement for blowing a gaseous fluid into the inner space; the blowing arrangement including at least one slot-shaped nozzle or aperture for generating a fluid flow curtain between the portal and the receiving region for workpieces; a pivotable guide plate having a guide contour formed thereon; and, the slot-shaped nozzle or aperture being arranged to direct the gaseous flow via the ceiling into the inner space along the guide contour in a flow direction inclined with respect to the floor.
The term “fresh air” is intended to be understood to be air which is in particular precompressed, heated and/or cleaned thermally and/or mechanically with a filter and/or dried and the status parameters of which are adjusted according to requirements. Fresh air may also be, for example, prepared exhaust air from a process chamber. Furthermore, fresh air may also be the exhaust gas from a heat engine or internal-combustion engine. With the supply of fresh air into the receiving region of the process chamber, it can be ensured that the solvent content of the air inside the process chamber does not exceed, when workpieces are dried, any threshold values above which drying processes are impaired and above which combustible solvents comprising dyes, paints, adhesives and/or coatings can bring about explosions because an explosion limit has been exceeded.
The invention is based on the notion that at least one air lock of a process chamber in a drying installation performs a dual function: fresh air which is supplied to the air locks and which produces a fresh air curtain can, on the one hand, be used to separate the inner space from the environment in technical flow terms and/or thermally. On the other hand, it is possible with the fresh air of the fresh air curtain for the solvent released during drying processes in the process chamber to be diluted sufficiently in that this fresh air is introduced into the process chamber.
Since the first function is charge-independent and the second function is charge-dependent, the inventors propose that this dual function of the air locks be separated. A volume flow which is directed into the process chamber is intended to be reduced or increased in terms of fluid in accordance with the charge of the process chamber. Fluids which may be considered include in particular fresh air and/or returned exhaust air. If a fresh air stream which is supplied to the process chamber of a drying installation is heated to a drying temperature, the adaptation of the fresh air volume stream to the charge allows a temporary reduction of the fresh air volume flow below its maximum value and consequently a reduction of the energy consumption.
The device preferably contains for the supply of fresh air in the installation at least one line which communicates with the receiving region and which has an opening for drawing in fresh air and which has a throughflow control device. The throughflow control device may comprise, for example, a throttle valve and/or an adjustable fan.
The installation may have in particular a device for agitating gaseous fluid in the receiving region by means of a circulating air line system which communicates with the receiving region and which is guided through a device for temperature control, in particular for heating gaseous fluid from the receiving region. The fresh air supplied to the process chamber can be supplied to the circulating air line system, for example, upstream or also downstream of a heat exchanger in the device for the temperature control. However, it is also possible to supply the fresh air in a line portion of the circulating air line system, by means of which line portion circulating air from the process chamber is directed to the device for temperature control or can be introduced into the process chamber by the circulating air which is temperature-controlled in the device for temperature control.
The installation may also contain a device for the supply of fresh air into the receiving region, which device has at least one line which has an opening for drawing in fresh air and which is connected to the circulating air line system. In this instance, a circulating air fan can be used in a cost-effective manner alternately or simultaneously to convey fresh air. A throughflow control device is optionally provided in the circulating air line system, the throughflow control device advantageously being arranged in a feed channel or a return channel of the circulating air line system. There are further optionally provided in the circulating air line system a heat exchanger and/or a heating device, the heat exchanger preferably transmitting heat from an exhaust gas flow into a fresh air flow within the device for supplying fresh air to the receiving region and a heating device preferably being connected, for example, to a solar thermal energy installation and/or a gas burner.
The line with the opening for drawing in fresh air may in particular open into a feed channel or return channel within the circulating air line system.
The installation may also contain a device for supplying fresh air to the receiving region, which device has at least one line which has an opening for drawing in fresh air and which is connected directly to the process chamber.
The throughflow control device is preferably part of a (superordinate) control or regulation circuit which supplies the receiving region with conditioned fluid, in particular with fresh air and optionally returned, prepared exhaust air. The throughflow control device may be connected directly or indirectly to a control or regulation circuit which contains a device for detecting a status parameter of the process chamber and which controls or regulates the quantity of fresh air which is introduced into the receiving region by means of the throughflow control device.
The process chamber in the installation may contain a device for monitoring operation of the process chamber, which device is configured for detecting a status parameter from the group set out below:
i. carbon content and/or solvent content of the atmosphere in the receiving region;
ii. number and/or weight and/or type and/or size of the surface of workpieces which are arranged in the receiving region;
iii. number and/or weight and/or type and/or size of the surface of workpieces supplied to the receiving region per time unit;
iv. temperature of the exhaust air of a burner in a device for the temperature control of circulating air;
v. temperature difference of gaseous fluid which is removed from the receiving region and which is supplied to the receiving region again;
vi. temperature difference of gaseous fluid from the receiving region which is supplied to a combustion chamber of a burner in a device for the temperature control of circulating air, and of exhaust air from the combustion chamber of the burner;
vii. heat quantity per time unit which is supplied to the process chamber.
The process chamber in the installation can also be constructed with a receiving region which is subdivided into a first receiving region and an additional receiving region, the device for introducing gaseous fluid into the inner space producing a fluid stream curtain between the first receiving region and the additional receiving region.
The device for introducing gaseous fluid into the inner space of the process chamber contains at least one nozzle or at least one aperture for producing a fluid stream curtain between the portal and the receiving region for workpieces. The at least one nozzle or at least one aperture is preferably used as a discharge opening for air which has been heated above ambient temperature and/or air which is compressed above ambient pressure (or a correspondingly processed inert gas such as CO2 or N2).
The process chamber may contain, for example, gaseous fluid whose temperature T is above 100° C. and/or for which a temperature difference in relation to the environment of the process chamber is more than 50° C. In an embodiment, fluid is introduced approximately perpendicularly in a downward direction into the process chamber. In another preferred embodiment, the fluid introduced through the nozzle has a temperature which is higher or lower by more than 20° C. than the (approximately static) fluid contained in the process chamber. Reference is further made mainly to a rigid or adjustable nozzle geometry, the invention also being able to be carried out with one or more simple apertures, respectively.
The inner space of the process chamber is preferably constructed so as to be of tunnel-like form. It has a floor and a ceiling. In that the at least one nozzle is in the form of a slot-type nozzle having a substantially rectangular discharge cross section, the gaseous fluid can be supplied via the ceiling of the inner space with a flow direction which is oblique in relation to the floor so that a flow eddy which comprises air and which is at least partially mixed with introduced fluid is formed at the side of the fluid stream curtain, which side is directed toward the floor or the inlet portal.
A notion of the invention is particularly that the fluid stream curtain can be produced with reduced energy consumption if the gaseous fluid which is introduced into the inner space via the at least one nozzle is guided by means of a guiding contour which projects into the inner space. It is particularly advantageous if that guiding contour can be pivoted. As a result, it is possible to adjust the fluid stream curtain in relation to the horizontal. An angle between 80° and 50° between the discharge direction and the horizontal is preferably adjusted.
If this angle between the discharge direction and the horizontal is adjusted, the fluid stream curtain produces a flow eddy at the lower side thereof when viewed in the flow direction, which side is directed toward the floor or a portal. The fluid flow of the fluid stream curtain presses counter to the gaseous fluid which is located in the region of the floor of the process chamber. The fluid flow of the fluid stream curtain overlaps and becomes mixed with fluid which leaves the process chamber in the region of the floor. In particular, it is possible by the guiding contour being pivoted for workpieces not to be impaired during introduction into the process chamber or during discharge. It is particularly advantageous if a wall which defines with the guiding contour a diffuser which contains a mixing chamber is arranged at the side of the guiding contour directed toward the portal. In relation to the central flow direction of the gaseous fluid from the at least one nozzle, the diffuser is constructed in an asymmetrical manner. The mixing chamber in the diffuser is arranged at the side of the fluid stream out of the nozzle, which side is directed downward when viewed in the flow direction.
The mixing chamber is positioned in the diffuser in such a manner that fluid at a side of the fluid stream curtain, which side is directed toward the portal (that is, outward from the inner space of the process chamber), is mixed with air from the region of the portal. In this instance, the air is drawn into the eddy by the gaseous fluid which flows through the nozzle or the aperture.
The wall may have one or more openings for the introduction of circulating air from the region of the portal.
In that an auxiliary chamber which acts as a “dead space” for gaseous fluid is formed at a side of the guiding contour directed away from the mixing chamber, it can be ensured that the stream of gaseous fluid being discharged from the nozzle or aperture is guided along the guiding contour without any flow breakdown. Preferably, lower flow speeds are present in the “dead space” than outside the dead space. As a result of the arrangement of an additional guiding wing in the mixing chamber, it is possible for large quantities of fluid to be guided back from the flow eddy into the fluid stream curtain.
In that a front wall which defines a retention space with the guiding contour is arranged at the side of the guiding wing directed toward the inlet portal, circulating air from the region of the inlet portal can be prevented from being discharged into the atmosphere, which air is redirected in the region of the guiding wing into an edge region of the inner space.
The front wall advantageously has one or more openings for the introduction of circulating air from the region of the inlet portal. The at least one nozzle may have a device for adjusting the flow quantity which is introduced through the nozzle for fluid. In that a plurality of nozzles having a device for adjusting the flow quantity which is introduced through the nozzle for fluid are provided, the fluid stream curtain can be adjusted in different manners in different portions between the inlet portal and the receiving region for workpieces.
The device for introducing gaseous fluid may have a heating device for heating the gaseous fluid. It is thereby possible for no condensate, for example, condensation water, to be produced in the region of portals of the process chamber. The process chamber is suitable for use in a drying and/or hardening installation. In particular, the process chamber may be integrated in a painting installation.
The fluid stream curtain is produced in the process chamber with gaseous fluid which is acted on with pressure and which is guided through a nozzle. Air from the region of a portal of the process chamber is added in the mixing chamber arranged adjacent to the nozzle to the gaseous fluid which flows out of the nozzle. The gaseous fluid which is guided through the nozzle is guided along a guiding contour which delimits the mixing chamber. That guiding contour separates the mixing chamber from an auxiliary chamber which is arranged adjacent thereto and which acts as a dead space for gaseous fluid.
The process chamber can be operated in particular in such a manner that a stream of gaseous fluid guided through a nozzle for producing a fluid stream curtain between the portal and the receiving region for workpieces is throttled or interrupted and/or wherein the direction of the fluid stream curtain is changed if a workpiece is moved through the portal. This ensures that the fluid stream curtain does not damage the surface of the coating of workpieces which are moved into and out of the process chamber.
The invention will now be described with reference to the drawings wherein:
The installation 1 shown in
The device 70 preferably contains a circulating air line system 72 which communicates with the drying zone 15. The circulating air line system 72 communicates with the receiving region 15 and has a feed channel 75 which acts as a circulating air recirculating channel and contains a return channel 77 which acts as a circulating air return channel for returning the circulating air. The circulating air line system 72 is guided through a heating device 63. In the device 70, there is a ventilator 61 with which the air for drying is introduced. With the device 70, the air can be retained at a defined temperature in the drying zone 15 in a circulating air operating state.
The installation 1 further preferably contains a device 74 and alternatively or additionally a device 74′ for the supply of fluid in the form of fresh air, which may optionally also be conditioned. The device 74, 74′ has a line 76, 76′ having an opening 78, 78′ for drawing in fresh air. In the line 76, 76′ there is a throughflow control device 80, 80′ which is constructed as a throttle valve. The line 76, 76′ is advantageously connected to the circulating air line system 72.
In order to direct away from the fluid atmosphere solvent which becomes volatilized in the drying tunnel 5 from paint, adhesives or coatings of the vehicle bodyworks 3, there is in the installation 1 a line 65 or a plurality of lines for exhaust air, via which air charged with solvent can be supplied from the drying tunnel 5 to a cleaning reactor 67. In the inlet lock 11 and the outlet lock 13 of the drying tunnel 5 there is a nozzle 17, 19 for producing a fluid stream curtain 21, 23. The nozzles 17, 19 are supplied with fresh air via a ventilator acting as a compressor for fresh air 25, 27 by a chamber 29, 31 which is arranged above the ceiling 6 of the drying tunnel 5. The nozzles 17, 19 preferably each have a narrow slot-like opening 33, 35 which extends substantially over the width of the drying tunnel 5 or over the width of the inlet or outlet portals 12, 14. The slot-like opening 33, 35 of the nozzles 17, 19 opens in the inner space 39 of the drying tunnel 5. The fluid being discharged from the nozzles 17, 19 is directed via a diffuser 16, 18 into the inner space of the drying tunnel 5. The diffuser 16, 18 extends in front of the nozzles 17, 19 over the width of the inlet or outlet portal 12, 14. The diffuser 16, 18 is constructed asymmetrically in relation to the direction of the fluid stream curtain 21, 23 and is delimited by a guiding plate having a guiding contour 211 and a front wall 215. The fluid which flows out of the nozzles 17, 19 is directed into the inner space of the drying tunnel by the guiding contour 211 of the guiding plate. A temperature sensor 69, 71 is located on the guiding contour 211 for detecting in a manner, which is advantageously possible, the temperature T of the fluid which is supplied to the inner space 39 via the nozzles 17, 19.
The fluid stream curtain 21, 23 preferably extends at an angle of 50°<a<80° with respect to the horizontal 37. It is directed into the inner space 39 of the drying tunnel 5. The fluid stream flowing out of the nozzles 17, 19 expands toward the floor 41 of the drying tunnel 5. With increasing distance from the opening 33, 35 of the nozzles 17, 19, the speed of the flow of the fresh air, which forms the fluid stream curtain 21, 23 as a gaseous fluid, decreases. The fluid stream curtain 21, 23 separates the gas atmosphere in the inner space 39 of the drying tunnel 5 from the ambient air 42. The fluid stream being discharged 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 drying tunnel 5. Alternatively or additionally, such a solvent sensor may be arranged in the exhaust air channel 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 Tsol1 which is preferably in a temperature range of 160° C.≤Tsol1≤250° C. In that the fluid stream curtain 21, 23 comprises fresh air, it can be ensured that a lower explosion limit for organic solvents in the drying zone 15 of the drying tunnel 5 is not exceeded. The preheating of the supplied fluid causes condensate not to occur 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 complied with, fresh air can be introduced into the drying portion 15 where applicable via the device 74 or 74′.
The control device 45 is connected to the throughflow control device 80 for adjusting the quantity of the fresh air supplied to the drying tunnel 5 via the device 74 or 74′. With the control device 45, the fresh air supplied via the line 76 or 76′ is adjusted to a predetermined value. The adjustment of the fresh air supply is carried out in accordance with the number detected by means of a sensor 49, 51 as process chamber operating state parameters in respect of the vehicle bodyworks moved per time unit through the drying zone 15 of the drying tunnel 5 and/or on the basis of the signals of the temperature sensors 69, 71 and/or the solvent sensor 73 and/or one or more other process chamber operating state parameters which allow statements concerning the composition of the gas atmosphere in the drying tunnel 5 and therefore the establishment of the fresh air requirement when the drying tunnel 5 is operated. The fresh air supply is adjusted in such a manner that, when the installation 1 is operated, the so-called lower explosion limit of the composition of the gas atmosphere in the drying tunnel 5 is not exceeded.
In order to detect process chamber operating state parameters, in a modified embodiment of the installation 1, there may also be provided as an alternative to the sensor 49 a photoelectric barrier for establishing the number of vehicle bodyworks moved per time unit through the drying tunnel 5. Alternatively or additionally to the sensor 49, it is also possible for this purpose to provide the installation with a measurement device with which the weight of the vehicle bodyworks 3 supplied to the drying tunnel 5 can be established and/or to provide a device with which the size of the surface of the vehicle bodyworks 3 provided with a surface coating can be detected. Furthermore, the installation 1 may also be provided with a device for detecting a digital code which is fitted to workpieces, for example, the vehicle bodyworks 3 or a skid 7, for example, a bar code which contains digital information concerning the size and quality of a surface coating which is applied to a workpiece, for example, to a vehicle bodywork 3, or a specific workpiece type.
In an installation according to the invention, the establishment of the fresh air requirement of the process chamber, in particular a drying tunnel for motor vehicle bodyworks, may be carried out, for example, as follows on the basis of a predefined type of workpiece:
The mass and number of workpieces which are present in the process chamber or which are on the way into the process chamber is established by means of a mass detection device and a batch number detection device. For each measurement value of the mass of a workpiece taking into consideration variations to be anticipated, which is taken into consideration as a result of the workpieces to be processed in the installation, a workpiece type is stored in the control device 45. In the control device 45, a conclusion can then be drawn from the type of workpiece established in the control device 45 with regard to the size of the painted surface of that workpiece. From the relevant value for the size of the surface, a fresh air requirement of the process chamber can then be determined via the solvent quantity discharged from this surface, which requirement is necessary so that, for example, the proportion of combustible solvent in the gas atmosphere of the process chamber 15 remains below the explosion limit.
According to the invention, therefore, in the installation a conclusion is drawn with regard to a specific workpiece, that is, a specific workpiece type, in particular from the mass of a workpiece established with the mass detection device. For the specific workpiece, a quantity of paint or coating applied thereto is then assumed and, from that assumed quantity of paint or coating, a conclusion is then drawn with regard to a solvent quantity taken up in the paint applied to the workpiece or the coating arranged thereon.
In combination with the batch number of the relevant workpieces in the process chamber, it is then possible to establish a total solvent quantity which is introduced into the process chamber during the drying of workpieces. The fresh air requirement for the process chamber can then be established therefrom in order to operate the chamber below the explosion limit.
It may be noted that a device for detecting the mass and batch number of workpieces may be formed according to the invention, for example, as a weighing device, with which the number of weighing operations is detected.
In order to take into account the thermal inertia of the entire system, it is advantageous to fit a device for detecting a workpiece parameter upstream of the process chamber. In the remaining time until the introduction of a workpiece into the process chamber, a desired process temperature and/or a desired composition of the gas atmosphere can then be adjusted in the process chamber, for example, by means of the quantity of fresh air introduced into the process chamber.
It should also be noted that the thermal inertia of an above-described installation is substantially determined by the thermal capacity of the process chamber and the magnitude of the air quantities supplied thereto and discharged therefrom.
In that the above-mentioned devices are connected to the control device 45, it is possible to control or to regulate the composition of the gas atmosphere by adjusting the fresh air supply in accordance with the requirements of the vehicle bodyworks 3 which are arranged in the drying tunnel 5 in particular taking into consideration the solvent content in the surface coating of the vehicle bodyworks 3.
The installation 1 can therefore be operated, for example, in the following operating states:
With the fluid stream curtain 21, 23, a constant fresh air volume flow is supplied into the inlet or outlet locks 11, 13 and ensures not only adequate sealing of the inner space 39 but also adequate dilution of a solvent content in the atmosphere of the drying zone 15. The drying tunnel 5 is acted on here in a charge-independent manner with the volume flow which is necessary for the solvent quantity supplied in the case of full loading.
With the fluid stream curtain 21, 23, a constant fresh air volume flow is supplied into the inlet or outlet locks 11, 13 and ensures adequate sealing of the inner space 39. In order to ensure adequate 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 quantity of fresh air supplied with the device 74 is adjusted with the control device 45 and changes with the charging of the installation 1. If fresh air is supplied to the drying zone 15 in an increased manner, a corresponding quantity of exhaust air must simultaneously be removed from the drying tunnel 5 via the line 65 so that the installation 1 is in equilibrium and no over-pressures or under-pressures are produced in the drying tunnel 5.
The fluid stream 210 being discharged from the opening 209 of the nozzle 17 is guided into the interior of the drying tunnel 5 along the contour 211 of a guiding plate 207 acting as a guiding wing. The length L of the contour 211 of the guiding plate 207 preferably corresponds to from 20 times to 40 times the slot width B of the nozzle opening 209.
At the side of the contour 211 directed toward the inlet portal 213 of the drying tunnel 5, there is a front wall 215. The front wall 215 extends over the width of the lock 11. The front wall 215 delimits the diffuser 16 with the contour 211, a ridge element 212 and the contour 211 of the guiding plate 207. The diffuser 16 is constructed in an asymmetric manner in relation to the main flow plane 202 of the fluid which flows out of the nozzle 17. The main flow plane 202 and the contour of the guiding plate 211 are at an angle φ relative to each other. The portion of the diffuser 16 which is at the side directed toward the front wall 215 in respect of the plane 204 which is symmetrical to the contour of the guiding plate 211 in relation to the main flow plane 202 and which encloses the angle 2φ with the contour of the guiding plate 211, acts as a mixing chamber 217 for gaseous fluid 219. The mixing chamber 217 is arranged so as to be recessed in relation to the ceiling 6 of the drying tunnel 5. The diffuser 16 with the mixing chamber 217 is in the lock 11 above the inlet portal 213. The mixing chamber 217 is adjacent to the inlet portal 213. The guiding plate with the contour 211 separates the mixing chamber 217 from an auxiliary chamber 216. The auxiliary chamber 216 opens in the interior 39 of the drying tunnel 5. The auxiliary chamber 216 forms a dead space for air from the drying tunnel 5. The auxiliary chamber formed at the rear of the guiding plate with the guiding contour 211 causes the fluid stream 210 to be guided on the guiding contour 211 as a result of the Coanda effect without any flow breakdown.
A diffuser 16 is formed by the guiding plate 211, on the one hand, and the front plate 215 which is arranged at the side of the guiding plate 211 directed toward the inlet portal 213, on the other hand. The diffuser 16 preferably takes up a portion of the air circulating in the flow eddy 407 inside the mixing chamber 217 thereof. In the mixing chamber 217, this air is carried and added to a portion of the gaseous fluid which flows out of the opening 209 of the nozzle 17 in the manner of a Venturi effect. This increases the volume flow of the fluid stream curtain 401 in the region of the arrows 402. The volume flow of the fluid stream curtain 401 may thus comprise a level of 30% or more of gaseous fluid which is supplied to the fluid stream which flows from the nozzle 17 via the mixing chamber 217. This results in a fluid stream curtain 401 which extends as far as the floor 41 of the drying tunnel 5 also being able to be produced with a comparatively small quantity of introduced fresh air.
The air from the mixing chamber 217 is thereby supplied to the flow eddy 407 again. This process results in only a small proportion of the gaseous fluid which is supplied via the nozzle 17 into the inner space 39 of the drying tunnel 5 leaving through the portal 213 of the lock 11 of the drying tunnel 5 again. The gaseous fluid which flows out of the nozzle 17 therefore reaches the interior of the drying tunnel 5 in accordance with the direction of the arrows 408 for the most part. A barrier with air circulating in the flow eddy 407 is produced in the region of the portal 213 of the lock 11 by means of the gaseous fluid which flows out of the nozzle 17. This barrier brings about a thermal separation of the inner space 39 of the drying tunnel 5 from the outer region. Furthermore, that barrier also prevents the introduction of dust and dirt particles into the inner space 39 of the drying tunnel 5.
In a modified embodiment of the inlet lock 501, it is also possible to provide a nozzle having a plurality of nozzle openings and having a plurality of control valves in order to adjust a fresh air stream for a drying tunnel.
A preferably pivotably arranged guiding plate 605 which acts as a guiding wing is associated with the nozzle 603 in the lock 601. The guiding plate optionally has an outer contour, which is at least partially curved. In particular, it extends over the entire width of the nozzle 603. The pivotable guiding plate 605 in the case of the opening 607 of the nozzle 603 is pivotably supported on the ceiling 608 of the lock 601 on a rotary joint 615. The pivotable guiding plate 605 projects into the interior 611 of the lock 601. The length L of the contour of the guiding plate 605 substantially corresponds to from 20 times to 40 times the slot width B of the nozzle opening. A front wall 609 is again arranged in the lock 601 opposite the pivotable guiding plate 605. In this instance, the pivotable guiding plate 605 and the front wall 609 also define together with a ridge element 612 a diffuser with a mixing chamber 613. As a result of the pivotability of the guiding plate 605, the geometry of the diffuser and the mixing chamber 613 can be changed in the case of the lock 601.
For the pivoting action, an actuating drive which is not shown in greater detail is associated with the guiding plate 605. By pivoting the guiding plate 605 in accordance with the double-headed arrow 617, it is possible to adjust an angle of incidence β in relation to the horizontal 616 and therefore the direction of a fluid stream curtain which is produced with gaseous fluid from the nozzle 603 in the lock 601. The guiding plate 605, on which the gaseous fluid which flows out of the nozzle 607 is guided, is displaced by the pivoting action. The shape of the flow eddy can thereby be changed, which shape is formed as a result of the fluid which flows out of the nozzle 603 at the side of the guiding plate 605 directed toward the opening 619 of the lock 601. By the guiding plate 605 being pivoted toward the ceiling 608 of the lock 601, it is possible to bring about a comparatively planar introduction of gaseous fluid into the lock. By the guiding plate 605 being moved upward and downward, the flow direction of the fluid flowing out of the nozzle can be adapted to the position and geometry of vehicle bodyworks which are moved by the lock 601 into the interior of the drying tunnel. Thus, it is possible for the fluid which flows out of the nozzle not to be redirected by the vehicle bodyworks toward the portal 619 and a paint coating which is applied to vehicle bodyworks and which is intended to be dried in the drying tunnel not to be dispersed or to suffer damage in the drying tunnel.
The structure of the lock 701 further corresponds to that of the lock 601 from
This measure allows the adjustment of a fluid stream curtain 917 at the portals of a drying tunnel which can be adjusted differently in accordance with the passage of workpieces, for example, vehicle bodyworks over the width B of the portal.
On the basis of an opening 1209 of the nozzle 1017, the fluid stream curtain 1401 (preferably comprising fresh air which flows in the direction of the arrows 1402) extends in the form of a leg 1403 which is bent to a greater or lesser extent in the direction of a floor 1041 of the lock 1011. At a side of the fluid stream curtain 1401 directed toward the inlet portal 1213 of the lock 1011, the fresh air which flows out of the nozzle 1017 produces a flow eddy 1407 of air. In the flow eddy 1407, the air flows with a flow direction which is indicated by the arrows 1406 about a center 1409. The air in the region of the center 1409 is substantially not moved. The air which is circulating in the flow eddy 1407 is at least partially mixed with the fresh air which is introduced via the nozzle 1017. The flow eddy 1407 extends from the floor 1041 as far as the ceiling 1006 of the inlet lock 1011.
The lock 1011 has a curved ridge wall 1215 at the side of a guiding plate 1211 which has a guiding contour, which side is directed toward the inlet portal 1213. The guiding plate 1211 and the ridge wall 1215 delimit and surround partially a diffuser 1210 with a downwardly open mixing chamber 1217. In the embodiment according to
A silhouette wall 1220 is arranged at the floor 1041 of the lock 1011 in the region of the portal 1213. The silhouette wall 1220 acts in particular as a flow barrier or as a flow guiding element at the floor side. The silhouette wall 1220 preferably comprises a spring steel or other temperature-resistant and/or corrosion-resistant steel. The silhouette wall 1220 can be pivoted or folded about a (horizontal) axis 1222 in accordance with the arrow 1224.
According to the invention, the mixing chamber 1217 takes up a small portion of the air circulating in the flow eddy 1407. In the mixing chamber 1217, this air is redirected with the flow wing 1218 as a result of a Venturi effect to the gaseous fluid which flows out of the opening 1209 of the nozzle 17. It is carried along by the gaseous fluid. That increases the volume flow of the fluid stream curtain 1401 in the region of the arrows 1402. The volume flow of the fluid stream curtain 1401 can thus comprise to a large degree gaseous fluid which is supplied to the fluid stream from the nozzle 1017 via the mixing chamber 1217 that results in a fluid stream curtain 1401 which extends as far as the floor 1041 of the drying tunnel also being able to be produced with a comparatively small quantity of fresh air being introduced.
The air from the mixing chamber 1217 is thereby supplied to the flow eddy 1407 again. That process results in only a small portion of the gaseous fluid which is supplied via the nozzle 1017 to the inner space 1039 of the drying tunnel leaving again through the portal 1213 of the lock 1011 of the drying tunnel. The gaseous fluid which flows out of the nozzle 1017 is therefore introduced into the interior of the drying tunnel for the most part in accordance with the direction of the arrows 1408. By means of the gaseous fluid which flows out of the nozzle 1017, there is produced in the region of the portal 1213 of the lock 1011 a barrier with air which is circulating in the flow eddy 1407 and which thermally separates the inner space 1039 of the drying tunnel from the outer region and furthermore also prevents an introduction of dust and dirt particles into the drying tunnel. The silhouette wall 1220 at the floor 1041 of the lock 1011 causes the flow eddy 1407 to be comparatively narrow. Only if a workpiece is moved into the drying tunnel does the silhouette wall in accordance with the arrow 1220 become folded briefly in the direction of the floor 1041. It should be noted that, alternatively or additionally, a foldable silhouette wall which corresponds to the silhouette wall 1220 can also be arranged in the upper region of the inlet portal. The installation 2001 shown in
The structure of the locks 2011 and 2013 corresponds to the structure of the inlet and outlet lock 11, 13 in the installation 1 shown in
A modified embodiment of the installation 2001 may also be constructed without any asymmetrical diffusers at the nozzles, for instance, if reduced demands are placed upon the tightness of the locks. For example, a mechanical closing of the corresponding locks may also be provided.
The installation 2001 contains a heating device 2023 which is in the form of a device for the thermal cleaning of exhaust air and which has a line 2025 for supplying hot clean gas from the drying tunnel 2005 and a heat exchanger 2027 which is used for heating exhaust air from the drying tunnel 2005. The exhaust air which is heated in the heat exchanger 2027 from the drying tunnel 2005 can be burnt in a combustion chamber 2029 of the heating device 2023 with or without the addition of additional fuel.
The heating device 2023 supplies heat to a plurality of heat transfer devices 2031, 2033, 2035, 2037 through a hot gas line 2036 which acts as a clean gas line. The heat transfer devices 2031, 2033 and 2035 are connected to the hot gas line 2036 in a row one behind the other. The heat transfer devices 2031, 2033, 2035 are preferably constructed substantially in the same manner. The device 2037 contains an air/air heat exchanger and is connected as the last of the heat transfer devices to the hot gas line 2036. The device 2037 is used for the temperature control of the fresh air which is guided to the nozzles 2014 for producing the fluid stream curtain 2021 comprising fresh air. The devices 2031, 2033 and 2035 each contain a heat exchanger 2039 which is connected with a hot gas line 2038 to the hot gas line 2036 and are configured for agitating circulation air in the drying portions 2015a, 2015b and in the retention zone 2016. The circulating air, which is guided by a circulating air line system 2041 which communicates with the receiving regions 2015a, 2015b and 2016 and which has a circulating air recirculating channel 2041a for removing circulating air from the drying tunnel 2005 and a circulating air supply channel 2041b for the introduction of circulating air into the drying tunnel 2005, is temperature-controlled in the heat exchangers 2039.
In the installation 2001, there are devices 2043 for the supply of additional fresh air into the receiving regions of the drying tunnel 2005. The devices 2043 have lines 2045 which communicate with a receiving region in the drying tunnel 2005 and which contain a throughflow control device 2047 which is in the form of a throttle valve.
It should be noted that the throughflow control device 2047 may also be provided alternatively or additionally with a fan. Fresh air is directed via the lines 2045 into the circulating air line system 2041 of the devices 2031, 2033, 2035 if the fresh air supplied through the nozzles 2014 to the drying tunnel 2005 is not sufficient to meet the fresh air requirement inside the drying tunnel.
The installation 2001 contains a control device 2046. The control device 2046 is connected to a first device 2051 for detecting a status parameter of the drying tunnel 2005 acting as a process chamber in the installation 2001. In the device 2051, an adjustment of the throttle valves 2052, 2055 in the lines 2038 for guiding hot gas through the heat exchangers 2039 and an adjustment of the throttle valves 2047 in the lines 2045 for supplying fresh air are detected by means of potentiometers or limit switches. It is possible to establish therefrom a fluid quantity which is supplied to the drying tunnel 2005 per time unit with the devices 2031, 2033, 2035 and 2037. As a result, it is again optionally possible to establish a thermal quantity which is supplied with the fluid if the fluid temperatures are measured via temperature sensors which are associated with the lines of a circulating air line system 2041 and a line 2045.
Furthermore, the control device 2046 is connected to a second device 2053 for detecting a status parameter of the drying tunnel 2005 which acts as a process chamber in the installation 2001. The device 2053 is in the form of a bodywork counting device, with which the number of motor vehicle bodyworks 2003 moved per time unit into the drying tunnel 2005 and therefore the quantity of motor vehicle bodyworks 2003 which are 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 TA in the hot gas line 2036. The temperature sensor 2007 is used for measuring the temperature of the hot gas which flows through the hot gas line 2036 at the outlet side of the heat transfer device 2037, with which the hot gas from the installation 2001 is released to the environment as a clean gas (clean gas over roof temperature).
The control circuit 2046 is connected to a control module 2056 for adjusting the speed of a ventilator 2057 which is arranged in the line 2025 and an additional control module 2059 for adjusting the speed of a ventilator 2061 which is used to draw fresh air into the line 2019 to the nozzles 2009 which produce a fluid stream curtain 2021 in the drying tunnel 2005.
The throughflow control devices 2047 in the devices 2043 for supplying fresh air and the speed of the ventilator 2057 are then adjusted by means of the control circuit 2046 in accordance with the value established by means of the device 2051 for the heat quantity supplied to the drying tunnel 2005 per time unit and the number established by means of the device 2053 in respect of bodyworks 2003 arranged inside the drying tunnel 2005.
So much fresh air is supplied into the line 2019 by means of the ventilator 2061 that the locks 2011, 2012 and 2013 are sealed by means of the fluid stream curtain 2021 produced with the nozzles 2009.
It should be noted that the control device 2046 can in principle also be in the form of a control circuit. It should further be noted that the fresh air supply by the heat transfer devices 2031, 2033, 2035 in the drying tunnel 2005 can also be controlled or regulated with a control device 2046, to which one or more of the subsequently set out measurement variables are supplied as process chamber operating state parameters for the installation 2001:
solvent introduction into the atmosphere in the receiving regions of the drying tunnel 2005;
total carbon content in the receiving regions of the drying tunnel 2005;
number of bodyworks arranged in the receiving regions of the drying tunnel;
temperature of the hot gas produced with the heating device 2023 in the hot gas line 2036 downstream of the device 2037 upstream of an exhaust air chimney;
temperature difference of the circulating air before and after the devices 2031, 2033 and 2035;
temperature difference of the exhaust air from the drying tunnel which is supplied to an exhaust gas cleaning installation and exhaust air which leaves the exhaust gas cleaning installation through an exhaust air chimney;
weight of a bodywork or size of a bodywork surface acted on with paint in order to conclude a solvent quantity therefrom.
It is advantageous if a plurality of measurement variables are combined in the control device 2046 as status parameters (process chamber operating state parameters). Thus, for example, a “clean gas over roof temperature” detected by means of the temperature sensor 2007 may also be detected as a primary measurement variable and an adjustment of the throttle valves 2052, 2055 for adjusting the hot gas flow in the hot gas lines 2036, 2038 (clean gas valve position) as a secondary measurement variable. The primary measurement variable is used to establish a fresh air/exhaust air volume flow and the secondary measurement variable is used for verifying, confirming and/or optionally correcting that fresh air/exhaust air volume flow.
After the fresh air/exhaust air volume flow is established by means of the “clean gas over roof temperature”, for example, a verification of that flow is carried out on the basis of the secondary measurement variable. For example, the variable fresh air volume flow is kept constant or increased until the positions of all the clean gas valve positions are again below a previously fixed value, if the position of the clean gas valve positions exceeds the fixed value which is dependent on the overall system and which may be between 50% and 100% of the opening degree. Such a combination of a plurality of measurement variables can particularly ensure that a sufficient thermal quantity is contained in the drying tunnel 2005 of the installation 2001.
The installation 2001 may be operated in particular as follows:
In a first operating mode which corresponds to a charging state A of the installation 2001 of, for example, A<50% in relation to the maximum possible capacity of workpieces in the process chamber in the form of a drying tunnel, a constant fresh air volume flow is supplied via the locks 2011, 2012 and/or 2013. An additional fresh air supply via the lines 2045 into the process chamber does not necessarily have to be carried out here.
In a second operating mode which corresponds to a charging state A of the installation 2001 of, for example, 51%≤A≤90% in relation to the maximum possible capacity of workpieces in the process chamber in the form of a drying tunnel, a constant fresh air volume flow is supplied via the locks 2011, 2012 and/or 2013. At the same time, additional fresh air is introduced into the process chamber by opening throughflow control devices 2047 in the form of throttle valves in the lines 2045 via the heat exchanger devices 2031, 2033, 2035 and/or 2037.
In a third operating mode which corresponds to a charging state of the installation 2001 of, for example, 91%≤A≥100% in relation to the maximum possible capacity of workpieces in the process chamber in the form of a drying tunnel, a constant fresh air volume flow is supplied via the locks 2011, 2012 and/or 2013 and the stream of the additional fresh air which is supplied to the heat transfer devices 2013, 2033, 2035 and/or 2037 is further increased by additional opening of the throughflow control devices 2047 in relation to the second operating mode.
It should be noted that the installation 2001 can also be operated in additional operating modes in which the throughflow control devices 2047 in the lines 2045 have a different opening position in relation to the above-mentioned operating modes. In particular, in principle it is also possible to change the operating mode of the installation 2001 in a stepless manner.
It should be particularly noted that the supply of fresh air into the drying tunnel 2005 in the installation 2001 can also be carried out at locations other than those shown in
In an alternative configuration of the installation 2001, for example, there may be provision for circulating air and/or fresh air to be supplied to the receiving regions 2015a, 2015b, 2016 of the drying tunnel 2005 via openings in the wall, in the ceiling and/or in the floor of the drying tunnel 2005. The supply of fresh air to the circulating air line system 2041 may also be carried out in principle in an installation 2001 described above with respect to the flow direction of the circulating air upstream or downstream of a heat exchanger 2039 in a heat transfer device 2031, 2033, 2035. It should further be noted that the supply of fresh air is possible both inside a heat transfer device 2031, 2033, 2035 and outside a heat transfer device 2031, 2033, 2035 to a circulating air recirculating channel 2041a or circulating air return channel of a circulating air line system 2041.
In order to adjust a defined volume flow for the fresh air, a ventilator can also be arranged in the line 2045 for fresh air. It is further possible for the fresh air to be supplied in a lock 2011, 2013, 2015 of the installation 2001 at the side of a fluid stream curtain 2021 directed into the interior of the drying tunnel 2005.
In order to explain the alternative configurations of the installation 2001 as set out above, additional installations according to the invention for drying are described below with reference to
Alternatively or additionally, it is also possible to convey fresh air through the line branch 2045b in the heat transfer device 2037 into the line 2019 by means of the ventilator 2061 into the line 2045. In this instance, the fresh air conveyed by means of the ventilator 2061 is not then guided or only partially guided through the heat exchanger 2039 in the heat transfer device 2037.
The fresh air guided in the line 2019 is introduced in the installation 2001′ in the heat transfer devices 2031, 2033 and 2035 in such a manner that it is introduced into the drying tunnel 2005 via the heat exchanger which is arranged in the heat transfer devices 2031, 2033 and 2035.
The fresh air introduced into the heat transfer devices 2031, 2033 and 2035 from the line 2045 can therefore be heated with heat from the clean gas which is guided in the hot gas line 2036.
A throughflow measurement device 2062 is arranged in the line portion 2019a of the installation 2001′. The throughflow measurement device 2062 controls an actuating member in a throughflow control device 2048. As a result, it can be ensured in the installation 2001′ that for different speeds of the ventilator 2061 the nozzles 2009, 2014 are supplied with a constant fresh air stream for producing a fluid stream curtain 2020, 2021. A throughflow measurement device 2063 is arranged in the line 2045. The throughflow measurement device 2063 is used to establish the quantity of fresh air supplied to the line 2045 by means of the ventilator 2061.
In the installation 2001′, a fresh air stream supplied into the line 2045 is adjusted by means of the throughflow control device 2048 in accordance with the number of bodyworks 2003 arranged inside the drying tunnel 2005, which number is established with the device 2053.
The throughflow measurement devices 2062, 2063 determine the quantity of fresh air supplied to the line 2019, 2045 by means of the ventilator 2061 by detecting the pressure decrease at an aperture which is arranged in the line portion with the throughflow measurement device 2062, 2063. It should be noted that the throughflow measurement device 2062, 2063 for detecting the flow of fresh air can contain, as an alternative thereto, a magnetically inductive sensor, an ultrasound measurement unit or an impeller.
Unlike in the installation 2001′ from
It should be noted that in a modified embodiment of the installation 2001′″ from
The installation 3001 shown in
The temperature sensors 3070, 3072, 3074 and 3076 are connected to the control device 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 portion of the hot gas line 3026, from which the clean gas which flows through the hot gas line 3026 is introduced into the ambient atmosphere. The temperature sensors 3070, 3072 are used for establishing the heat which is discharged into the drying tunnel 3005 by the clean gas flowing through the hot gas line 3026 by the difference of the temperatures measured by means of those temperature sensors ΔTH−T1−T2 being established. With the temperature sensors 3074 and 3076, there is established the difference of the temperatures ΔTU:=T3−T4 of circulating air which flows from the drying tunnel 3005 in the circulating air recirculating channel 3041a and circulating air which is mixed with fresh air and which is directed through the circulating air supply channel 3041b into the drying tunnel 3005.
The control device 3046 controls the speed of the ventilator 3057 in the line 3025 and the adjustment of the throughflow control devices 3047 for adjusting the quantity of fresh air supplied to the line system 3041 in accordance with the temperature difference ΔTH, ΔTE detected by means of the temperature sensors 3070, 3072, 3074 and 3076. Alternatively, the control device 3046 may also be constructed as a control circuit which controls the speed of the ventilator 3057 in the line 3025 and the adjustment of the throughflow control device 3047 on the basis of the signal of the temperature sensors 3070, 3072, 3074 and 3076.
The installation 4001 shown in
In this instance, the control device 4046 controls the speed of the ventilator 4057 in the line 4025 and the adjustment of the throughflow control devices 4047 for adjusting the quantity of fresh air supplied to the line system 4041 in accordance with the mass of the vehicle bodyworks 4003 supplied to the drying tunnel 4005, which mass is detected by means of the balance 4078.
Additional modifications and developments of an installation according to the invention may result inter alia from a combination of different features of the above-described advantageous embodiments.
In conclusion, the following preferred features of the invention should be emphasized: According to a first aspect of the invention, a process chamber 5, 2005 has an inner space 39 having a receiving region 15, 2015a, 2015b, 2016 for workpieces 3, 2003. The process chamber 5, 2005 has a portal 12, 14, 2015, 2017 for the supply or discharge of workpieces 3, 2003. The process chamber 5, 2005 is constructed so as to have a device 17, 19, 25, 29, 33, 37, 35, 2014 for introducing gaseous fluid into the inner space 39, which device has at least one nozzle 17, 19, 2014 or aperture 803 for producing a fluid stream curtain 21, 23, 2021 between the portal 12, 14, 2015, 2017 and the receiving region 15, 2015a, 2015b for workpieces 3, 2003. The process chamber 5, 2005 has a device 74, 2043 for supplying fresh air with which fresh air can be introduced into the receiving region 15, 2015a, 2015b at a side of the fluid stream curtain 21, 23, 2021 facing away from the portal 12, 14, 2015, 2017.
According to a second aspect of the invention, the device (74, 2043) may contain for the supply of fresh air at least one line (78, 2045) which communicates with the receiving region (15, 2015a, 2015b) and which has an opening for drawing in fresh air and which has a throughflow control device (80, 2047).
According to a third aspect, the throughflow control device may in this case comprise a throttle valve (80, 2047) and/or an adjustable fan.
According to a fourth aspect of the invention, a device (70, 2031, 2033, 2035) for agitating gaseous fluid in the receiving region (15, 2015a, 2015b) by means of a circulating air line system (72, 2041) may be provided, which system communicates with the receiving region (15, 2015a, 2015b) and which is guided through a device (2031, 2033) for temperature control, in particular for heating gaseous fluid from the receiving region (15, 2015a, 2015b).
According to a fifth aspect of the invention, the device (74, 2043) for the supply of fresh air into the receiving region (15, 2015a, 2015b) may in this case contain at least one line (76, 2045) which has an opening (78) for drawing in fresh air and which is connected to the circulating air line system (72, 2041) and which comprises a throughflow control device (80).
According to a sixth aspect, the throughflow control device may in this case comprise a throttle valve (80, 2047) and/or an adjustable fan.
According to a seventh aspect of the invention, the line (76) with the opening (80) for drawing in fresh air may open into a circulating air return channel (77) in the circulating air line system (72).
According to an eighth aspect of the invention, the throughflow control device (80, 2047) may be connected to a control or regulation circuit (45, 2049) which receives the signal of a device (49, 69, 73, 2051) for detecting a status parameter of the process chamber (5, 2005) and which controls or regulates the quantity of fresh air which is introduced into the receiving region (15) via the device for supplying fresh air by means of the throughflow control device (80, 2047) in accordance with at least one detected status parameter.
According to a ninth aspect of the invention, the device (2051) is configured for detecting a status parameter of the process chamber (5, 2005) from the group set out below:
i carbon content and/or solvent content of the atmosphere in the receiving region (2015a, 2015b, 2016);
ii. number and/or weight and/or type and/or size of the surface of workpieces (2003) which are arranged in the receiving region;
iii. number and/or weight and/or type and/or size of the surface of workpieces (2003) supplied to the receiving region per time unit;
iv. temperature of the exhaust air from the combustion chamber (2029) of a burner in a device for the temperature control of circulating air;
v temperature difference of gaseous fluid which is removed from the receiving region (2015a) and which is supplied to the receiving region (2015a) again;
vi. temperature difference of gaseous fluid from the receiving region (2015a) which is supplied to a combustion chamber (2029) of a burner in a device for the temperature control of circulating air, and of exhaust air from the combustion chamber (2029) of the burner;
vii. heat quantity per time unit which is supplied to the process chamber (2005).
According to a tenth aspect of the invention, the receiving region may be subdivided into a first receiving region (2015a) and an additional receiving region (2015b) and the device (2014) for introducing gaseous fluid into the inner space produces the fluid stream curtain (2021) between the first receiving region (2015a) and the additional receiving region (2015b).
According to an eleventh aspect of the invention, the inner space (39) may be constructed so as to be of tunnel-like form and may have a floor (41) and a ceiling (6), wherein the at least one nozzle (17, 19) or aperture (803) is in the form of a slot which supplies the gaseous fluid to the inner space (39) via the ceiling (6) with a flow direction (402) which is oblique in relation to the floor (41) and the gaseous fluid which is supplied to the inner space (39) produces a flow eddy (407) which comprises air and which is at least partially mixed with introduced fluid at the side of the fluid stream curtain (21, 23), which side is directed toward the portal (12, 14). According to a twelfth aspect of the invention, the gaseous fluid which is supplied to the inner space (39) may be fresh air.
According to a thirteenth aspect of the invention, the gaseous fluid which is introduced into the inner space (39) via the at least one nozzle (17, 19) or aperture (803) may be guided by a diffuser (16, 2116) into the inner space (39).
According to a fourteenth aspect of the invention, the guiding contour (606) may be formed on a pivotable guiding wing (605).
According to a fifteenth aspect of the invention, a wall (215, 1215) which defines with the guiding contour (211, 1211) a diffuser (16, 18) having a mixing chamber (217, 1217), in which fluid from the flow eddy (407, 1407) is mixed with air from the region of the portal (213, 1213), may be arranged at the side of the guiding contour (211, 1211), which side is directed toward the portal (213, 1213).
According to a sixteenth aspect of the invention, mixed fluid from the mixing chamber (407, 1407) is drawn into the inner space (39, 1039) by the gaseous fluid which flows through the nozzle (17, 19, 1017) or the aperture (803).
According to a seventeenth aspect of the invention, the wall (709, 809) has one or more openings (816) for the introduction of circulating air from the region of the portal (213).
According to an eighteenth aspect of the invention, an auxiliary chamber (216) which acts as a dead space for gaseous fluid is formed at a side of the guiding contour (211) directed away from the mixing chamber (217).
According to a nineteenth aspect of the invention, a guiding wing (1218) which is subjected to flow with gaseous fluid from the flow eddy (1407) and which guides the fluid back from the flow eddy (1407) into the fluid stream curtain (1401) is arranged in the mixing chamber (1217).
According to a twentieth aspect of the invention, the at least one nozzle (503) in the installation may have a device (511) for adjusting the flow quantity which is introduced through the nozzle (503) for fluid, and/or a plurality of nozzles (903, 905, 907) having a device for adjusting the flow quantity which is introduced through the nozzle for fluid may be provided in order to adjust the fluid stream curtain in different manners in different portions between the inlet portal and the receiving region for workpieces (912).
According to a twenty-first aspect of the invention, a pivotable flow barrier (1220) may be provided for controlling a fluid flow which is formed in the inner space (1039).
According to a twenty-second aspect of the invention, the device for introducing gaseous fluid may have a heating device (43, 44) for heating the gaseous fluid.
According to a twenty-third aspect of the invention, an installation configured according to one of the above aspects may be in the form of a drying and/or hardening installation and/or in the form of a painting installation.
According to a twenty-fourth aspect, the invention relates to a method for operating an installation configured according to one of the aspects specified above, wherein for producing the fluid stream curtain (21, 23, 2021) gaseous fluid which is acted on with pressure is guided through the nozzle (17, 19) or aperture (803) and wherein, in a mixing chamber (217) arranged adjacent to the nozzle (17, 19), air from the region of a portal (213) or the inner space (39) of the process chamber (5) is added to the gaseous fluid which flows out of the nozzle (17, 19).
According to a twenty-fifth aspect of the invention, the gaseous fluid which is guided through the nozzle (17, 19) may in this case be guided along a guiding contour (211) which delimits the mixing chamber (217) and which separates in particular the mixing chamber (217) from an auxiliary chamber (216) which is arranged adjacent thereto and which acts as a dead space for gaseous fluid.
According to a twenty-sixth aspect of the invention, in the abovementioned method a stream of gaseous fluid guided through the nozzle (17, 19) or aperture (803) for producing a fluid stream curtain (21, 23) between the portal (12, 14) and the receiving region (15) for workpieces (3) may be throttled or interrupted and/or the direction of the fluid stream curtain (21, 23) may be changed if a workpiece (3) is moved through the portal (12, 14).
According to a twenty-seventh aspect of the invention, in the abovementioned method the fluid stream curtain (21, 23, 2021) may be produced with a quantity of fresh air which remains constant in terms of the mean time over a time period and which is guided through the nozzle (17, 19) or the aperture (803), and wherein a variable quantity of fresh air, which is controlled or regulated in accordance with a process chamber operating state parameter from the group set out below, is supplied with the device (74, 2043) for supplying fresh air to the inner space (39) during the time period:
i. carbon content and/or solvent content of the atmosphere in the receiving region (2015a, 2015b, 2016);
ii. number and/or weight of workpieces (2003) which are arranged in the receiving region;
iii. number and/or weight of workpieces (2003) supplied to the receiving region per time unit;
iv. temperature of the exhaust air from the combustion chamber (2029) of a burner in a device for the temperature control of circulating air;
v. temperature difference of gaseous fluid which is removed from the receiving region (2015a) and which is supplied to the receiving region (2015a) again;
vi. temperature difference of gaseous fluid from the receiving region (2015a) which is supplied to a combustion chamber (2029) of a burner in a device for the temperature control of circulating air and of exhaust air from the combustion chamber (2029) of the burner;
vii. heat quantity per time unit which is supplied to the process chamber (2005).
It is understood that the foregoing description is that of the preferred embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2012 207 312.4 | May 2012 | DE | national |
This application is a continuation-in-part application of patent application Ser. No. 15/230,078, filed Aug. 5, 2016, which, in turn, is a continuation-in-part application of patent application Ser. No. 14/398,721, filed Nov. 3, 2014 (now U.S. 9,423,179, issued Aug. 23, 2016), which, in turn, is the national stage of PCT/EP2013/058817, filed Apr. 26, 2013, designating the United States and claiming priority from German patent application no. 10 2012 207 312.4, filed May 2, 2012, the entire contents of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15230078 | Aug 2016 | US |
| Child | 15960283 | US | |
| Parent | 14398721 | Nov 2014 | US |
| Child | 15230078 | US |
