EP2368642B1 - Ventilation device for spray paint assemblies - Google Patents

Description

The present invention relates to a ventilation device for spray painting systems according to the preamble of claim 1, spray painting systems according to the preamble of claim 7 and method for aeration of spray painting systems according to the preamble of claim 8.

In such spray painting equipment articles, such as trucks, buses and rail vehicles and parts thereof or any other objects, provided with a coating material by spraying, namely, for example, with primers, basecoat films, paint layers, outer paint layers, clearcoat films, sealing layers and the like. The spraying of the coating material is usually done manually by means of spray guns, which are usually acted upon with compressed air and coating material, in which case the coating material is entrained in the compressed air jet until it impinges on the surface to be coated.

In order to ensure a high quality of the coating, it is necessary to supply supply air to the spray booth and to remove the air contained in the spray booth as exhaust air, to which usually motor-driven fans are used, which are controlled by suitable control devices.

In this context, special attention should be paid to the overspray that occurs during spray coating, since this overspray can be deposited from the air on the surfaces to be coated and thus lead to contamination. The more overspray occurs, the higher must be the ventilation performance to dissipate this overspray before it separates. By the way, also g e-statutory requirements are arranged to ensure this discharge and currently the requirement is to ensure a sinking rate of the overspray of about 0.3 m / s. The larger the overspray volume, the higher the fan power must be to maintain this rate of descent.

To comply with this requirement, the services of the supply and exhaust air systems are usually designed accordingly. This is a high energy expenditure associated with the operation of the spray booth, especially when a period of time just not sprayed or when partial painting is performed.

First approaches to reduce this energy expenditure, are that according to the doctrine of WO 2006/133551 A1 the control device specifically controls the performance of the supply air and exhaust air devices depending on whether a spray coating is ever made or not. For this purpose, it is checked by means of a compressed air-controlled switch, whether necessary for the injection process compressed air is removed. When a flow of air is detected, a certain fan power is set and, in the absence of compressed air flow, fan power is reduced to a reduced level.

To further improved S teuerung the fan performance on quality of the coating can be additionally provided that after finding no further compressed air flow, the reduced fan power is adjusted only after a certain time to safely remove any existing overspray from the spray booth.

In addition to this solution, it is already known to control the fan power gradually, namely with a full load level of 100% power, a partial load stage with about 70% power and a Standbystufe with about 50% power. As a result, the energy intake can be controlled even more needs. However, overall there is still a very high expenditure of energy, which makes the operation of such spray booths expensive.

Object of the present invention is therefore to provide a ventilation device for spray painting, with which the energy consumption can be further reduced. In particular, an even more accurate demand-driven fan performance is to be ensured. At the same time a Spritzlackieranlage should be provided.

This object is achieved with a ventilation device according to claim 1 and a spray painting according to claim 8. Advantageous further developments are specified in the dependent claims.

For the special case of the ventilation of powder coating plants discloses the EP 0 899 022 A1 to measure the powder mass flow to reduce the overspray. From this prior art, the independent claims are based on the general concept.

The inventor has found, surprisingly, that the hitherto conventional control of the fan power via the compressed air flow can not be correlated precisely enough with the forming overspray. This may be due to the fact that the amount of overspray does not correlate one-to-one with the amount of compressed air used. This means that with the same overspray different amounts of compressed air can be present, so that the measurement of the amount of compressed air can not be used to exact statements about the overspray conditions in the S pritzkabine. Such a case is e.g. when using the airless spray method, where little or no compressed air is used for the paint spraying.

Therefore, the inventor has solved the hitherto conventional compressed air quantity measurement and proposes according to the invention the measurement of the coating material flow for controlling the fan power. Thus, a much more accurate statement about the exact overspray conditions is possible because now the primary coating material flow is measured and not the secondary for the injection process compressed air flow. As a result, now can be taken much more accurately to different types of spray guns, especially modern spray guns that produce significantly less overspray.

Furthermore, the invention provides that the control device is adapted to use the viscosity of the coating material as a control variable for controlling the supply air and / or exhaust air devices. Then it is guaranteed that the performance is particularly reliable adapted to the actual resulting overspray. It is advantageous if at least one viscosity detector is provided to determine the viscosity.

The following will always talk about control and taxes. Nevertheless, it can also be associated with a regulation or rules.

The ventilation device according to the invention for spray painting systems with at least one spray booth, in the coating material is sprayed onto objects to be coated, thus has at least one air supply device for acting on the spray booth with supply air, at least one exhaust device for removing exhaust air from the spray booth, drive means for driving the Zuluft- and the exhaust air devices and a control device for controlling the supply air and exhaust air devices, wherein the control device is adapted to use the coating material flow as a control variable for controlling the supply air and / or A b air devices, and is characterized in that the control device adapted to use the viscosity of the coating material as a control variable for controlling the supply air and / or exhaust air.

Accordingly, independent protection is claimed for the ventilation method for spray painting systems with at least one spray booth in which coating material is sprayed onto objects to be coated, wherein the spray booth is supplied with supply air and exhaust air is discharged from the spray booth, the supply air and the exhaust air flows by means of a control device The control device uses the coating material flow as a control variable for controlling the supply air and / or exhaust air devices, which is characterized in that the viscosity of the coating material is used as a control variable for controlling the supply air and / or exhaust air.

In addition, of course, it may further be provided that the actuation of the one or more spray guns serves as an input variable for the control device, for example, to control discrete fan power, such as full load, partial load, standby and off.

Preferably, the supply air and exhaust air devices on motor-driven fans and / or pumps, so that the admission of supply air and the discharge of the exhaust air takes place with these motor-driven fans. Furthermore, it is preferred if the control device is adapted for the separate control of the supply air and exhaust air devices, so that the supply air and exhaust air flows can be controlled separately by means of the control device.

In an advantageous development, it is provided that at least one frequency converter with different discrete frequencies is provided, the output frequency of which can be controlled discretely for stepwise regulation of the motor power of the motor-driven fans and / or pumps as a function of the control variable. For this purpose, in turn, different power levels, such as full load, partial load, standby and off can be defined, these levels can now be controlled more precisely. Alternatively or additionally, it can also be provided that the motors used in the supply air and / or exhaust air devices are multi-layered, in particular two-stage, with regard to their performance.

In the venting method according to the invention, it is accordingly advantageous if, depending on setpoint values of the control variable, the motor power of the motor-driven fans and / or pumps is controlled stepwise discretely, whereby of course one or more frequency converters can be used, but also any other suitable control.

In a particularly preferred embodiment, it is provided that at least one frequency converter is provided, the output frequency of which is continuously controllable in dependence on the control variable for continuously controlling the motor power of the motor-driven fans and / or pumps. Then the fan or pump power can be controlled very precisely, namely analogously to the overspray volume, so that the overspraysink speed is always minimal fan power is ensured. Of course, this infinitely variable frequency converter can advantageously also have discretely adjustable frequencies.

In the ventilation method according to the invention, it is accordingly preferred if, depending on the control variable, the motor power of the motor-driven fans and / or pumps is continuously controlled, whereby of course one or more frequency converters can be used, but also any other suitable control.

Furthermore, it is advantageous if a flow quantity detector, for example based on ultrasound or the Coriolis force, is used to determine the flow of coating material, since this determination then takes place very precisely.

It is expedient if the spray booth has at least two sections which can be ventilated separately from one another and the control device is adapted to separately control the supply air and exhaust air devices assigned to each section as a function of the flow of coating material in the individual sections. Then, on the one hand, in different sections due to the shaping of the object to be coated differently occurring overspray can be reacted. On the other hand, smaller objects then do not always have to operate the entire spray booth, so that the fan performance can be specifically adapted to the size of the object.

The following embodiments are advantageous in the ventilation method, wherein the developments can be used in addition to the basic form individually or in any combination.

In the basic form is a ventilation process for spray painting with at least one spray booth, in the coating material is sprayed onto objects to be coated, in which the spray booth supplied with supply air and exhaust air is discharged from the spray booth, the Zuluft- and the exhaust air flows by means of a Control device preferably controlled separately wherein the admission of supply air and the discharge of the exhaust air takes place in particular with motor-driven fans, wherein the control device uses the coating material flow as a control variable for controlling the supply air and exhaust air devices.

Advantageously, it is provided that the motor power of the motor-driven fans and / or pumps is controlled in stages in a discrete manner as a function of setpoint values of the control variable.

Appropriately, it is provided that, depending on the control variable, the motor power of the motor-driven fans and / or pumps is continuously controlled.

It is preferably provided that the flow of coating material is determined by ultrasound measurement or by measuring the Coriolis force and thus the control variable is generated.

Particularly preferably, it is provided that the spray booth has at least two separately ventilatable sections and in each section the associated supply air and exhaust air in dependence. The flow of coating material in the individual sections is controlled separately.

Self-contained protection is claimed for a spray painting installation which has the ventilation device according to the invention.

Fig. 1

die erfindungsgemäß verwendete Spritzkabine,

Fig. 2

die Ansteuerung der Spritzkabine gemäß Fig. 1 in einer ersten Ausführungsform und

Fig. 3

die Ansteuerung der Spritzkabine gemäß Fig. 1 in einer zweiten Ausführungsform.

The features, characteristics and further advantages of the present invention will now be described with reference to the description of two preferred embodiments of the invention in conjunction with the figures. Showing:

Fig. 1

the spray booth used in the invention,

Fig. 2

the control of the spray booth according to Fig. 1 in a first embodiment and

Fig. 3

the control of the spray booth according to Fig. 1 in a second embodiment.

In Fig. 1 is purely schematic of the spray booth 1 used in the invention shown in a plan view. The spray booth 1, which is provided for the painting of rail vehicles, has two sections 2, 3, which are arranged horizontally separated within the spray booth 1 and, for example, by a roller door 4 or the like. From each other are spatially separable. Within the spray booth 1 on opposite walls two over almost the entire length and the height of the spray booth 1 movable stages 5, 6 are provided, on which workers by means of spray guns not shown objects (not shown), which are located inside the spray booth 1 with Coating coating material can.

For the removal of overspray occurring during the spraying process, in the ceiling of the spray booth 1 filter devices (not shown) are provided with filters and in the bottom with filters, e.g. Staubabscheidevorrichtungen, provided exhaust air devices (not shown), which are each designed as a motor-driven fans. The fan power is adapted, for example, in the first section 2 of the spray booth 110,000 m3 / h air exchange and in the second section 3 55,000 m3 / h. In this case, a uniform Zulufteinrichtung is used with a two-stage engine power of 40 kW and 115 kW and for the exhaust device in the first section 2 is an engine power of 75 kW and for the exhaust device in the second section, a motor power of 37 kW. For the uniform Zulufteinrichtung is preferably provided that this is closed with blinds or the like. Connections with two sections 2, 3 separately to supply each section defined supply air.

In Fig. 2 is now shown purely schematically the control 10 of the spray booth 1 in a first preferred embodiment. It can be seen that coating material from a container 12 can be fed to a first spray gun 11 assigned in the first section 2. Furthermore, a second spray gun 13 assigned to the second section 3 can be supplied with coating material from a second container 14. Both spray guns are without (eg airless method) or with compressed air (not shown) acted upon to deliver coating material, as indicated by the arrows. In order to measure the coating material flow separately for both spray guns 11, 13, ultrasound coating material flow detectors 15, 16 are for example provided, which supply their measured variables to a control device 17 as control variables.

The signals received via the control device 17 drive four frequency converters 18, 19, 20, 21, wherein the first frequency converter 18 controls the engine of the feeder, the second frequency converter 19 controls the engine of the exhaust air device for the first section 2, the third frequency converter 20 the motor the exhaust device for the second section 3 and the fourth frequency converter 21 controls the motor of the pump for the wet dedusting device, ie the filter device of the exhaust device.

The control 10 is now operated as follows. If only one of the two detectors 15, 16 detects a flow of coating material, then the first frequency converter 18 is controlled so that the engine of the air supply device is moved to partial load. At the same time, depending on which detector 15, 16 detects the flow, the motor of the exhaust air device associated with the respective section is switched on via the respective frequency converter 19, 20. In order to take into account a possible movement of the platforms 5, 6 into the respective other section, it may advantageously be provided that when the platform 5, 6 is moved into the respective other section 2, 3, for example by means of overflow detectors, the respective other exhaust device is actuated.

If both detectors 15, 16 detect a coating material flow, then the engine of the air supply device in the full load stage at full power and via the second and third frequency converter 19, 20 both motors of the exhaust air devices are switched on the first frequency.

If, on the other hand, both detectors 15, 16 do not detect any flow of coating material, then all the motors are switched off via the first, second and third frequency converters 18, 19, 20.

In addition, it is provided that when changing the signal of one of the detectors 15, 16, the respective controlled frequency converter 18, 19, 20 are operated with a short acceleration, when the signal switches to detection of coating material flow, and operated with long delay, when the signal switched to detection of no coating material flow. As a result, overspray overhangs are considered at the end of the injection process.

In addition, the supply air can be supplied via a suitable e.g. modulating heating source (not shown) are heated, in which case temperatures of about 20 ° C to 24 ° C are common, but of course other temperatures can be used, depending on the coating material. Then it is expedient if the heat source via the control device 17 is driven. Namely, that it is turned on when responding at least one of the detectors 15, 16 but otherwise is turned off.

In addition, a step of tempering the applied coating or the tempering of the spray booth 1 by means of the heated supply air can be provided for the operation and / or tempering of the spray booth 1. For this purpose, the first frequency converter 18 is operated in standby mode, the heating source and the respective exhaust air motors are turned on, but the pump for the wet dedusting device is turned off.

To generate the various engine powers of the feeder of full load, part load, standby and off, the first frequency converter 18 has discrete control frequencies of e.g. 40 Hz, 30 Hz, 20 Hz or 0 Hz.

In Fig. 2 a second embodiment of the actuator 30 is shown purely schematically, wherein the same and similar elements as shown in the first embodiment according to Fig. 2 are provided with the same or similar reference numerals. In terms of the exact structure and the functional description is essentially based on the representations Fig. 1 referred to below and only the differences.

Unlike the first embodiment according to Fig. 1 It is here provided that a unitary detector 15 'detects a flow of coating material which is stored in, for example, a central container 12'. In addition, the modulating heat source 31, which can heat the supply air, and the temperature detector 32, which determines the temperature of the supply air, are also shown here.

In the event that the operation is detected exclusively a spray gun 11, 13, the corresponding second or third frequency converter 19, 20 are driven to operate the corresponding motors and the first frequency converter 18 switches the engine of the air supply device to partial load. The heating source 31 is operated in dependence on the temperature value determined via the temperature detector 32 so that the temperature of the supply air is maintained at a desired value. In addition, the pump of the wet dedusting device is turned on via the fourth frequency converter 21.

If both spray guns 11, 13 are actuated, however, the engine of the air supply device by means of the first frequency converter 18 is operated at full load.

If no spray gun 11, 13 is actuated, all motors are turned off and the heat source 31. Unless an annealing step is provided, then the heat source 31 is still operated and at the same time the required exhaust air and the engine of the air supply means of the first frequency converter is kept on standby.

In the present case, the operation of the spray booth 1 has been described with fixed, ie discrete, performances for the motors via the first, second and third frequency converters 18, 19, 20 through the detection of a flow of coating material, in principle determining only the fact whether there is a flow of coating material or Not. This is much more precise than the determination of a Durkluftflusses, since even with existing compressed air flow not necessarily a coating must be connected to an overspray.

Alternatively, of course, it may also be provided that the exact flow of coating material is utilized as a control variable in order to set the engine power of all fan motors specifically to predetermined values, that is, to control discrete power levels.

Furthermore, alternatively, an exact analog, i. continuous control of the respective engine performance via the determination of the exact coating material flows carried out by the first, second and third frequency converter 18, 19, 20 are steplessly controlled depending on the respective coating material flow. The engine of the wet dedusting device can also be steplessly controlled.

While the frequency converters (18, 19, 20, 21) have been described in the context of controlling the motor power of the motorized fans and / or pumps in dependence on the control variable, such frequency converters (18, 19, 20, 21) can of course also be used for controlling the power of any other drive device of the supply air and / or exhaust air devices are used.

Furthermore, it is provided that the fan power is specially adapted to the viscosity of the coating material. In this case, for example, the mixture of colorant and solvent is considered as the coating material. For this purpose, special viscosity meters (not shown) in the supply lines between the coating material container 12, 12 ', 14 and spray guns 11, 13 are provided which make a fine control of the fan line. This means that the preset load levels are separately regulated in their services via the viscosity detection.

For example, assuming a higher overspray for a lower viscosity coating material, that is less solid content, than for a higher viscosity coating material, fan performance may increase higher-viscosity coating material compared to those with lower viscosity can be reduced.

This type of air flow control and regulation ensures that paint mist and solvents are sorted and discharged there only with the required effort where they arise during painting.

At the same time, the energy consumption of the system is considerably reduced. The exact air flow rates are set during commissioning and fine-tuning, for example according to the specification 0.3 m / s sink rate for the overspray. Thus, typically about 60% of the electrical energy and about 50% of the heat energy can be saved.

From the foregoing, it has become clear that with the present invention spray painting can be operated energetically much more optimized, so that the overall coating can be done more cost-effective. While the foregoing has always referred to spray painting equipment, it will be understood that ventilation apparatus and methods are also contemplated for spray coating equipment operating with spray guns 11, 13, and the like, which are not coated with paints, but with other coating materials such as paints. Powder coatings work. Even if the presented spray booth 1 has two sections 2, 3, the spray booth according to the invention can also have only one or numerous sections. The ventilation device according to the invention can always be used advantageously.

Claims (10)

1. A ventilation device for spray painting arrangements comprising at least one spray paint booth (1) in which coating material is sprayed onto objects to be coated and at least one air supply device for supplying the spray paint booth with input air at least one air output device for removing output air from the spray paint booth, drive devices for driving air inlet and air outlet devices and a control device (17) for preferably separately controlling the air inlet- and air outlet devices, wherein the air inlet and air outlet devices include in particular motor driven fans and/or pumps, wherein the control device (17) is configured to use the coating material flow as a control variable for controlling the air inlet- and/or air outlet devices, wherein the control device (17) is configured to use the viscosity of the coating material as a control variable for controlling the air inlet and/or air outlet devices.
2. The ventilation device according to claim 1, wherein at least one frequency inverter (18, 19, 20, 21) with various discrete frequencies is provided whose output frequency is controllable in a discrete manner as a function of the control variable for incrementally controlling a motor power of the motor driven fans and/or pumps.
3. The ventilation device according to claim 1 or 2, wherein at least one frequency inverter (18, 19, 20, 21) is provided whose output frequency is continuously controllable as a function of the control variable for continuously controlling the motor power of the motor driven fans and/or pumps.
4. The ventilation device according to one of the preceding claims, wherein at least one flow volume detector is provided for determining the coating material flow, in particular based on ultrasound or a Coriolis force.
5. The ventilation device according to one of the preceding claims, wherein the spray cabin (1) includes at least two sections (2, 3) that can be ventilated separately from one another and the control device (17) is adapted to separately control the air inlet- and air outlet devices associated with each section (2, 3) as a function of the coating material flow in the particular sections (2, 3).
6. The ventilation device according to one of the preceding claims, wherein at least one viscosity detector is provided for determining viscosity.
7. A spray painting arrangement including at least one spray painting booth (1) in which coating material is sprayed onto objects to be coated, wherein the spray painting booth includes a ventilation device according to one of the preceding claims.
8. A method for ventilating spray painting arrangements including at least one spray paint booth (1) in which coating material is sprayed onto objects to be coated, wherein the spray paint booth (1) is supplied with inlet air and outlet air is removed from the spray paint booth, wherein the inlet- and outlet air flows are controlled through a control device (17), wherein the control device (17) uses the coating material flow as a control variable for controlling the air inlet and/or air outlet devices, wherein the viscosity of the coating material is used as a control variable for controlling the air inlet and/or air outlet devices.
9. The method according to claim 8, wherein a spray painting arrangement according to one of the claims 1 through 7 is used.
10. The method according to claim 8 or 9, wherein one or plural spray guns are provided and their actuation is used as another control variable for controlling the air inlet and/or air outlet devices.

Images