Media applicator and system for applying media

Abstract

A media applicator (21) for applying media is provided. The media applicator (21) comprises at least one flow channel (22) with an inlet (22e) for feeding in at least one medium and with an outlet (22a) for discharging the at least one medium fed in through the inlet (22e). At least one valve (1) with a controllable valve state is provided in the at least one flow channel (22), and the at least one valve (1) is designed such that the valve state can be switched between a blocking state, a forward flow state, and a reverse flow state as required. Furthermore, a system (20) and a method (100) for applying media are proposed.

Description

Field of the invention

[0001] The present disclosure relates to a media applicator and a system for applying media. Background and general description of the invention

[0002] Media applicators and systems for applying media are known. Known systems, such as painting systems for paint lines, include such applicators for dispensing media, such as paints, and applying them to surfaces to be painted or target surfaces. Particularly during media changes or when such systems are shut down, the problem of media residues or paint residues in the media lines arises. This complicates a smooth media change and can lead to loss of the usable media material. To remove such media residues, special, sometimes aggressive flushing agents are used, which entails additional costs and increased environmental pollution. This problem was already addressed in an earlier patent document DE 100 13 973 A1. The approach proposed therein, using continuous media circulation in a media application system, provides a remedy, but only partially solves the problem.Not all media lines, especially those around the applicator and / or spray head, are accessible for the media circuit. Furthermore, such systems are relatively complex, especially if they are designed to dispense multiple different media.

[0003] An object of the embodiments of the present disclosure is to provide a novel media applicator and a novel system and method for applying media which enable the media residues to be removed in an efficient and environmentally friendly manner.

[0004] To achieve this objective, according to a first aspect, a media applicator for applying media is provided. The media applicator can be configured, in particular, to deliver individual or mixed media for application. The media applicator can be configured, in particular, as part of a media application system or a media application installation.

[0005] The media applicator comprises at least one flow channel with an inlet for feeding at least one medium and with an outlet for discharging the at least one medium fed into the inlet. At least one valve with a controllable valve state is provided in the at least one flow channel. In this context, a medium can fundamentally be any medium that is conducive to flow or can be discharged via the media applicator, such as, in particular, liquid, gas, gel, smoke, vapor, powder, or a mixture thereof.

[0006] The media applicator can be designed, in particular, to dispense one or more media in order to apply the medium(s) to a target surface, optionally by means of a spray head or outlet nozzle connected on the outlet side. The spray head or outlet nozzle can be designed, in particular, as part of the media applicator or as a separate part. The media applicator can, in particular, be designed in the form of a bell or gun of a painting system or a coating system in order to dispense one or more paint colors as media and apply them to a surface to be painted or a target surface.

[0007] The inlet of the at least one flow channel can be configured in particular so that a media supply line can be connected to the inlet. In particular, the inlet can be configured to be connected to the media supply line via a screw, rotary, or plug connection and / or via a quick-release mechanism and to be sealed against the medium.

[0008] The at least one valve is designed such that the valve state can be switched between a blocking state, a forward flow state and a reverse flow state as required. In particular, the at least one valve can be designed as a three-state valve or designed such that it can assume at least these three states. By changing the state of the valve, the flow of the medium through the flow channel can be influenced. In particular, in the forward flow state of the valve, the flow of the medium in the forward direction is enabled, i.e. from the inlet towards the outlet, and in the reverse flow state or backflow state of the valve, the flow of the medium in the reverse direction is enabled, i.e. from the outlet towards the inlet. In the blocking state of the valve, the flow of the medium is blocked in both directions.

[0009] Switching the valve to the reverse flow state or backflow mode allows the medium to flow back into the media supply line. The possibility of backflow of the medium can be used, in particular, to transport media back to the respective containers or tanks. This can reduce the consumption or waste of useful media and the flushing media required for flushing media supply lines.

[0010] The at least one valve can be designed such that the valve state can be controlled as a function of a current pressure difference or a current pressure gradient between the inlet and the outlet of the at least one flow channel. The current pressure difference essentially corresponds to the difference between a pressure P e currently prevailing at the inlet of the valve and a pressure P a currently prevailing at the outlet of the valve: ΔP = P e - P a . A change in the pressure difference can occur, for example, through a pressure change in a media supply line connected to the inlet side of the flow channel, so that a switching operation of the valve can be triggered by a change in the pressure in the media supply line. The valve can therefore be controlled in a particularly simple manner via the pressure change in the media supply line.In particular, the valve can be controlled virtually automatically by pressure without additional control devices, allowing the applicator to be designed particularly compactly. Eliminating the complex valve controls also creates space for accommodating multiple or many flow lines in the media applicator, allowing the applicator to dispense or apply more different media or colors, possibly simultaneously, than is currently possible.

[0011] The at least one valve can be designed such that it is switched from the blocking state to the forward flow state when the medium pressure or the pressure difference prevailing there exceeds a predefined first threshold value. If, for example, the pressure in the medium supply line is increased, in particular by means of a compressor, to such an extent that the medium pressure or the pressure drop exceeds the first threshold value, the valve is switched to the forward flow state, so that the medium flows through the flow channel in the direction Outlet can flow.

[0012] The first threshold value for opening the valve in the outlet direction can be between 2 bar and 10 bar, in particular between 3 bar and 9 bar, especially between 4 bar and 6 bar, absolute pressure (abs). As an example, the first threshold value can be 5 bar (abs). By appropriately selecting or setting the first threshold value, it is possible, in particular, to prevent the valve from opening prematurely, in particular before a spray pressure builds up in the supply line. In particular, the first threshold value can be set or selected such that the valve can be opened and closed in a reliable and controllable manner by a corresponding pressure change in the supply line.

[0013] The at least one valve can be configured to switch from the blocking state to the reverse flow state when the pressure differential or the pressure in the media supply line falls below a predefined second threshold. If, for example, the pressure in the media supply line is reduced to such an extent that the pressure gradient falls below the second threshold, the valve switches to the reverse flow mode automatically or without additional measures. This pressure reduction in the media supply line can be reduced to such an extent, for example, by means of a compressor operated in suction mode, which acts on the suction line. This allows the medium to flow backward in the media supply line.

[0014] Alternatively or cumulatively, the media supply line, possibly including the media tank, can be set to an operating pressure during system operation. The operating pressure can be an offset pressure that is higher than 1 bar absolute pressure (bar abs), for example 1.5 bar (abs) or 2 bar (abs), i.e. 1 atm overpressure. The overpressure can be provided by a compressor. It is sensible to set an operating pressure of up to a maximum of 5 bar (abs), since maintaining an operating pressure requires energy and there is always an effort to reduce the system's energy consumption as much as possible. In the example of an operating pressure of 2 bar (abs), the first threshold value can, for example, be above 2 bar (abs) up to, for example, 5 bar or 10 bar (abs), or furthermore, for example, in the interval from 3 to 5 bar (abs). Relative to the operating pressure, the first threshold value can therefore be, for example, 0.5 to 10 bar higher, preferably 0.5 to 3 bar.The second threshold value can be below the operating pressure, for example at least 0.1 bar or at least 0.2 bar below the operating pressure. For an exemplary offset pressure of 2 bar (abs), this would be 1.9 to 1 bar (abs). This pressure range is particularly advantageous because backflushing only requires venting to the atmosphere, so this process can be carried out in a particularly energy-efficient manner. The valve can be adapted to the operating pressure such that the threshold values ​​are arranged around the operating pressure. For example, the valve can be designed such that the first threshold value is above the operating pressure and the second threshold value is below the operating pressure.

[0015] By appropriately selecting or setting the second threshold value, it is possible in particular to prevent the valve from opening prematurely, in particular before a corresponding negative pressure builds up in the supply line. In particular, the second threshold value can be set or selected such that the valve can be opened and closed in a reliable and controllable manner by a corresponding pressure change in the supply line. In particular, the second threshold value is between 10 bar and 1 bar lower than the first threshold value, in particular between 9 bar and 3 bar, and especially between 6 bar and 4 bar lower. If the operating pressure is not changed compared to the atmosphere, i.e. is 1 bar (abs), then the second threshold value can, for example, be between 0.9 bar (abs) and 0.5 bar (abs), for example 0.8 bar (abs). The first threshold value can then, for example, be 2 bar (abs).

[0016] The at least one valve can comprise at least one closing body and at least one spring element, wherein the at least one spring element can be designed such that the at least one closing body can be held in a closed position for blocking the valve by means of the at least one spring element. In particular, the spring element can be designed to exert a spring force on the closing body, such that the closing body is held in the closed position by the spring force of the spring element. The closing behavior of the valve can be influenced by adjusting the spring constant or spring properties of the at least one spring element. In particular, the valve can be calibrated such that the first and / or the second threshold value can be precisely set.

[0017] The at least one spring element can comprise at least one overpressure spring for holding the at least one closing body in the closed position until the first threshold is exceeded, and at least one underpressure spring for holding the at least one closing body in the closed position until the second threshold is undershot. The switching behavior of the at least one valve can be precisely adjusted using the dedicated springs responsible for the switching processes. In particular, the first threshold and the second threshold can be adjusted independently of one another.

[0018] In some embodiments, the media applicator comprises a spray head connected to the outlet side of the at least one flow channel for spraying the at least one medium. The spray head can, in particular, comprise one or more nozzle-like openings that atomize the medium into fine droplets or mist. The openings can, in particular, be arranged to enable particularly uniform media application and / or to apply the medium in specific patterns.

[0019] According to a second aspect, a system for applying media is provided. The system can be designed in particular as a painting system or painting installation for applying paints. The system comprises at least one media applicator according to the first aspect, wherein the at least one flow channel of the media applicator is connected via at least one media supply line to a media supply unit having at least one media container. The system further comprises a pump unit having a number of pumps for conveying the at least one medium through the at least one media supply line. The at least one pump is designed to convey the at least one medium from the media supply unit towards the media applicator in a first operating mode and from the media applicator back towards the media supply unit in a second operating mode.The media supply unit can be configured to recover the used medium, i.e., it can be configured as a media supply and recovery unit. In particular, the at least one pump can be operated in suction mode when the at least one valve is in the reverse flow state. The reverse flow of the medium can clear the media supply line or the media feed tract of media residues, for example, before a media change or at the end of operation. This can reduce the cleaning and maintenance effort required to ensure smooth operation of the system. In addition, the returned medium can be collected in a corresponding media container of the media supply unit (or media supply and recovery unit) so that it can be later fed back into the process or reused.

[0020] The at least one valve of the media applicator can be designed such that the valve state can be controlled as a function of a current pressure difference ΔP between the inlet and the outlet of the at least one flow channel, and wherein the at least one pump can be designed to generate a pressure difference ΔP required to control the at least one valve. The valve can thus be controlled in a particularly simple manner via the pressure change in the media supply line. In particular, the valve can be controlled without additional control devices, so that the applicator can be designed to be particularly compact. In other words, pressurizing the valve can automatically set the desired valve position, i.e., quasi-automatically determine the selection of the valve position in one of the three valve positions, in particular, through pressure.

[0021] According to a third aspect, a method for applying media is proposed. The method can be carried out, in particular, by means of a system according to the second aspect. The system can, in particular, comprise an applicator with at least one flow channel with at least one controllable valve. The controllable valve can, in particular, be designed such that the valve state can be switched between a blocking state, a forward flow state, and a reverse flow state as required.

[0022] According to the method, in one method step, the at least one valve is placed in the forward flow state. In the forward flow state of the valve, the at least one medium can flow through the valve or through the valve channel and thus also through the flow channel of the media applicator, so that the medium contained therein can be discharged and applied to a target surface, for example, via a spray body.

[0023] In a method step, the at least one valve can be returned from the forward flow state to the blocking state, in particular to interrupt the media flow through the media applicator.

[0024] In one method step, the at least one valve is placed in the reverse flow state. In the reverse flow state of the valve, the at least one medium can flow back through the valve or through the valve channel and thus also through the flow channel of the media applicator via the media supply lines to the media supply. The returned medium can, in particular, be fed back into the process or reused at a later time.

[0025] In some embodiments of the method, the at least one valve is configured such that the valve state can be controlled as a function of a current pressure difference between the inlet and the outlet of the at least one flow channel. The method may, in particular, comprise controlling the current pressure difference to control the at least one valve. The pressure difference can, in particular, be easily controlled by controlling or regulating the pressure in a corresponding media supply line, so that the media applicator can be easily controlled without complex control devices.

[0026] In some embodiments of the method, the at least one valve is configured to switch from the blocking state to the forward flow state when the pressure difference exceeds a predefined first threshold. According to the method, the first threshold for discharging media can be exceeded in one method step.

[0027] In some embodiments of the method, the at least one valve is designed such that it is switched from the blocking state to the reverse flow state when the pressure precipitate falls below a predefined second threshold value. According to the method, the second threshold value can be undercut in one method step, in particular to free the media applicator and the media supply lines of media residues. In particular, this method step can be carried out before each media change or before the system is shut down. By freeing the media tract of media residues and by transporting the media residues back to the media supply unit (or media supply and recovery unit), both media consumption and maintenance effort can be reduced. This is because complex flushing and cleaning processes can be avoided.

[0028] In the following, the invention is described in more detail using exemplary embodiments and with reference to the figures, wherein identical and similar elements are partly provided with the same reference numerals and the features of the various exemplary embodiments can be combined with one another. Short description of the characters

[0029] It shows: Fig. 1 shows a schematic cross section of a valve according to an embodiment in a first state, Fig. 2 a schematic cross section of the valve according to Fig. 1 in a second state, Fig. 3 a schematic cross section of the valve according to Fig. 1 in a third state, Fig. 4 a schematic cross section of a valve according to a second embodiment in a first state, Fig. 5 a schematic cross section of the valve according to Fig. 4 in a second state, Fig. 6 a schematic cross section of the valve according to Fig. 4in a third state, Fig. 7 shows a system for applying media according to an embodiment, and Fig. 8 shows a schematic flow diagram of a method according to an embodiment. Detailed description of the invention

[0030] Fig. 1 shows a schematic cross-section of a valve according to an embodiment in a first state. In the illustrated embodiment, the valve 1 comprises a valve body 2 or base body with a valve channel 3, a closing body 4, a spring element 5, and a support 6 formed in the valve channel 3.

[0031] The valve channel 3 is elongated and extends between a first end 7 and a second end 8 opposite the first end 7. In the exemplary embodiment shown, the closing body 4 has a convex outer surface. In particular, the closing body 4 is essentially spherical. The spring element 5 is in the form of an elongated spiral spring which extends along the valve channel 3. The spring element 5 is fastened with a first longitudinal end to a support 6 fixed in the valve channel. The spring element 5 is fastened with a second longitudinal end opposite the first longitudinal end to the closing body 4. The support 6 has through openings so that, when the valve 4 is open, a medium can flow through the support 6.

[0032] Near the second end 8 of the valve channel 3, a first recess 9 is formed in the valve channel 3. The first recess 9 has an inner surface that is substantially conformal to the outer surface of the closing body 4 and is designed such that the closing body 4 can be received in the first recess 9 to close the valve channel 3.

[0033] The valve channel 3 further comprises a second recess 10, which is formed adjacent to the first recess 9 on the side of the first recess 9 facing away from the second end 8. The second recess 10 has a substantially similar shape to the first recess 9 and is larger in size than the first recess 9.

[0034] In the Fig. 1In the first state of the valve 1 shown, the closing body 4 is located in the region of the first recess 9 and blocks the valve channel 3. This state thus corresponds to the above-described blocking state of the valve 1, in which the valve 2 is closed.

[0035] Fig. 2 shows a schematic cross section of the valve according to Fig. 1 in a second state. The Fig. 2 The state of the valve 1 shown corresponds to the forward flow state. In the forward flow state, the spring element 5 is in an expanded state and functions as a tension spring, with the second longitudinal end of the spring element 5 extending beyond the second end 8 of the valve channel 3. The closing body 4 fixed to the second longitudinal end of the spring element 5 is located outside the valve channel 3.

[0036] Such a state of the valve 1 can be achieved in particular when the pressure gradient across the valve or the pressure difference between the inlet and the outlet of the valve 1 generates a force on the closing body 4, which overcomes the spring force of the spring element 5 and pushes the closing body 4 out of the first recess 9 or out of the valve channel 3. The valve 1 is thus open and the medium contained therein, driven by the pressure gradient, can flow through the valve channel 3, which in Fig. 2 symbolically represented by an arrow pointing to the right. The threshold value of the pressure difference at which the spring force is overcome depends on factors such as the diameter of the valve channel 3, the shape and dimensions of the closing body 4, and the spring properties or spring constant of the spring element 5. By selecting these parameters, the first threshold value of the pressure difference at which the valve 1 switches from the blocking state ( Fig. 1 ) into the forward flow state ( Fig. 2 ) is switched on. In particular, the spring element can be configured such that the first threshold value of the pressure difference is approximately 5 bar. In some embodiments, the first threshold value is between 2 bar and 10 bar, in particular between 3 bar and 9 bar, especially between 4 bar and 6 bar.

[0037] Fig. 3 shows a schematic cross section of the valve according to Fig. 1 in a third state. The Fig. 3 The state of the valve 1 shown corresponds to the reverse flow state. In the reverse flow state, the spring element 5 is in a compressed state, with the closing body 4 attached to the second longitudinal end of the spring element 5 being located in the region of the second recess 10.

[0038] Such a state of the valve 1 can be achieved in particular when, due to a negative pressure difference between the inlet and outlet of the valve 1, a force is generated on the closing body 4, which overcomes the spring force of the spring element 5 and moves the closing body 4 from the first recess 9 into the second recess 10. Due to the dimensions of the second recess 10, the medium can flow between the outer surface of the closing body 4 and the inner surface of the second recess 10. The valve 1 is thus open and the medium therein, driven by the negative pressure difference, can flow backwards through the valve channel 3, which in Fig. 3 symbolically represented by an arrow pointing to the left.

[0039] The threshold value of the pressure difference at which the spring force is overcome depends on factors such as the diameter of the valve channel 3, the shape and dimensions of the closing body 4, and the spring properties or spring constant of the spring element 5. By selecting these parameters, the second threshold value of the pressure difference at which the valve 1 switches from the blocking state ( Fig. 1 ) into the reverse flow state ( Fig. 3 ) is switched on. In particular, the spring element can be configured such that the second threshold value of the pressure difference is approximately -5 bar. In some embodiments, the second threshold value is between -10 bar and -2 bar, in particular between -9 bar and -3 bar, especially between -6 bar and -4 bar.

[0040] The spring element 5 can thus function as an overpressure spring, which gives way at a certain overpressure or at a certain positive pressure difference and opens the valve channel 3, cf. Fig. 2 . The spring element 5 can simultaneously function as a vacuum spring, which yields at a certain negative pressure or a certain negative pressure difference and opens the valve channel 3, Fig. 3 . The embodiment of the Fig. 1 has a particularly simple design. The spring element 5 determines both the first threshold value of the pressure difference and the second threshold value of the pressure difference.

[0041] Fig. 4shows a schematic cross-section of a valve according to a second embodiment in a first state. In the embodiment shown, the valve 1 also comprises an elongated valve channel 3 with a first end 7 and a second end 8 opposite the first end. A valve mechanism is formed between the first end 7 and the second end 8. The valve mechanism comprises a first closing body 4 with a first closing ring 11 and a second closing body 4' with a second closing ring 11', as well as a first spring element 5 and a second spring element 5'.

[0042] The valve mechanism is fixed to the valve body 2 or base body by a support 6 and sealed against the base body. In this exemplary embodiment, the support 6 has a substantially cylindrical side wall, a substantially flat front wall, and a rear wall opposite the front wall. Openings are provided centrally in the front wall and in the rear wall. A support surface for receiving or sealing the second locking ring 11' is formed on the inside of the second wall.

[0043] The first locking body 4 is columnar and has an elongated stem 12, a wide foot 13 at a first end and a wide head 14 at a second end where the first locking ring 11 is formed.

[0044] The second closing body 4' extends between the front wall and the rear wall of the support 6 and has an axial through-bore for receiving the first closing body 4. At one end, the second closing body 4' has a wide head 14' to which the second locking ring 11' is attached. In the area of ​​the head 14', a support surface for receiving or sealing the first locking ring 11 of the first closing body is formed on the inside of the second closing body 4'.

[0045] The Fig. 4The state of the valve 1 shown corresponds to a basic or blocked state of the valve 1. In this state, the first closing ring 11 of the first closing body 4 lies on the support surface of the second closing body 4' and the second closing ring 11' of the second closing body 4' lies on the support surface of the support 6. The first spring element 5 is in the form of a spiral spring which extends between the foot 13 of the first closing body 4 and the head 14' of the second closing body 4'. The first spring element 5 is clamped with a first end against the foot 13 of the first closing body 4 and with a second end against the head 14' of the second closing body 4'. The second spring element 5' is also in the form of a spiral spring and extends between the front wall of the support 6 and the head 14' of the second closing body 4'.The second spring element 5' is clamped between the front wall of the lintels 6 and the head 14' of the second closing body 4'.

[0046] In the illustrated embodiment, the two spring elements 5, 5' are in compression mode. The first spring element 5 presses the foot 13 of the first closing body 4 away from the head 14' of the second closing body 14', so that the first locking ring 11 is pressed onto the support surface of the second closing body 4'. The second spring element 5' presses the head 14' of the second closing body 4' away from the front wall of the support 6, so that the second locking ring 11' is pressed against the support surface of the support 6. Thus, both closing bodies 4 and 4' are sealed at their respective support surfaces, and the valve 1 is in the blocking state or blocking mode.

[0047] Fig. 5 shows a schematic cross section of the valve according to Fig. 4 in a second state. The Fig. 5 The state of the valve 1 shown corresponds to the forward flow state, in which the first spring element 5 is compressed more strongly than in the basic state. The length of the first spring element 5 shortens, and the distance between the foot 13 of the first closing body 4 and the head 14' of the second closing body decreases. The locking ring 11 of the first closing body 4 detaches from the support surface of the second closing body 4', so that the first closing body 4 no longer blocks the valve channel 3.

[0048] Such a state of the valve 1 can be achieved in particular when the pressure gradient across the valve channel 3 or the pressure difference between the inlet and outlet of the valve 1 generates a pressure force on the closing body 4, which overcomes the spring force of the first spring element 5 and pushes the first closing body 4 out of the closed position. The valve 1 is thus open and the medium therein, driven by the pressure gradient, can flow through the valve channel 3, which in Fig. 5 symbolically represented by an arrow pointing to the right. The first spring element 5 thus functions as an overpressure spring, which yields at a certain overpressure or a certain positive pressure difference and opens the valve channel 3.

[0049] The threshold value of the pressure difference at which the valve is switched from the blocking state to the forward flow state, or the first threshold value, depends, among other things, on the spring constant of the first spring element 5. By selecting a suitable spring element as the first spring element 5, the first threshold value of the pressure difference at which the valve 1 is switched from the blocking state ( Fig. 4 ) into the forward flow state ( Fig. 5 ) is switched on. In particular, the first spring element 5 can be designed such that the first threshold value of the pressure difference is approximately 5 bar.

[0050] In some embodiments, the first threshold value is between 2 bar and 10 bar, in particular between 3 bar and 9 bar, especially between 4 bar and 6 bar. By appropriately selecting the first spring element 5 or setting the first threshold value, it is possible, in particular, to prevent the first closing body from opening in an uncontrolled manner, for example, in the event of any pressure fluctuations, in particular before an operating pressure builds up in the media supply line.

[0051] Fig. 6 shows a schematic cross section of the valve according to Fig. 4 in a third state. The Fig. 6The state of the valve 1 shown corresponds to the reverse flow state, in which the second spring element 5' is compressed more strongly than in the basic state. The length of the second spring element 5' shortens, and the distance between the front wall of the support 6 and the head 14' of the second closing body 4' decreases. The locking ring 11' of the second closing body 4' detaches from the support surface of the support 6, so that the second closing body 4' no longer blocks the valve channel 3.

[0052] Such a state of the valve 1 can be achieved in particular when, due to a negative pressure difference between the inlet and outlet of the valve 1, a force is generated on the closing bodies 4 and 4', which overcomes the spring force of the second spring element 5' and releases the second closing body 4' from the support surface on the support 6. The medium can then flow between the second closing ring 11' and the support 6, through the second spring element 5' and through the opening in the front wall of the support 6. The valve 1 is thus open and the medium therein, driven by the negative pressure difference, can flow backwards through the valve channel 3, which in Fig. 6 symbolically represented by two arrows pointing to the left. The second spring element 5' thus functions as a vacuum spring, which yields at a certain negative pressure or a certain negative pressure difference and opens the valve channel 3.

[0053] The threshold value of the pressure difference at which the valve is switched from the blocking state to the reverse flow state, or the second threshold value, depends, among other things, on the spring constant of the second spring element 5'. By selecting a suitable spring element as the second spring element 5', the second threshold value of the pressure difference at which the valve 1 is switched from the blocking state ( Fig. 4 ) into the reverse flow state ( Fig. 6 ) is switched on. By a suitable selection of the second spring element 5' or setting the second threshold value, it is possible in particular to prevent the second closing body 4' from opening in an uncontrolled manner, for example in the event of any pressure fluctuations, in particular before a nominal negative suction pressure builds up in the media supply line.

[0054] With the dedicated spring elements 5, 5' responsible for the switching processes, the threshold values ​​of the Figures 4 to 6valve 1 shown can be precisely adjusted independently of each other. In addition, the valve 1 is characterized by Figures 4 to 6 increased robustness, since the two spring elements 5, 5' work exclusively in compression mode.

[0055] Fig. 7shows a system for applying media according to one embodiment. The system 20 comprises a media applicator 21 according to the first aspect. In the embodiment shown, the media applicator 21 comprises a number of flow channels 22, each with an inlet 22e and an outlet 22a, as well as a number of valves 1 of the type described above for opening and closing the flow channels 22. The flow channels 22 are connected on the inlet side to media supply lines 23. The system 20 also comprises a media supply unit 24 (or media supply and recovery unit) with a number of media containers F1...F23, which are connected via the media supply lines 23 to the corresponding flow channels 22 of the media applicator 21. The system further comprises a pump unit 25 with a number of pumps M1...M23 or compressors for conveying media through the media supply lines 23.A spray head 26 is arranged downstream of the media applicator 21 and is designed to spray media discharged through the passage channels 22.

[0056] The Fig. 7 The system 20 shown further comprises a cleaning device 27 or rinsing device with an air inlet 28 and a rinsing agent inlet 29. The cleaning device 27 is connected to the spray head 26 by means of a rinsing line 30.

[0057] The pumps M1...M23 are designed to operate in both compression mode and suction mode. In compression mode, the pumps M1...M23 pump media from the media supply unit 24 or from the respective paint or media containers F1...F23 through the media supply lines 23 toward the media applicator 21. In suction mode, the media is returned from the media applicator 21 toward the media supply unit 24 or into the respective media containers F1...F23.

[0058] Fig. 8 shows a schematic flow diagram of a method according to an embodiment. The method 100 can be carried out in particular by means of a system 20 according to Fig. 7 In particular, the system 20 can comprise a media applicator 21 for applying media, wherein the media applicator 21 has at least one flow channel 22 with at least one controllable valve 1. The controllable valve 1 can in particular be designed as a three-state valve of the type described above, the state of which can be switched between a blocking state, a forward flow state, and a reverse flow state as required, cf. Figures 1 to 6 above.

[0059] In a method step 110, the system 20 can be provided in a basic state. In the basic state, the at least one valve 1 of the media applicator 21 is in the blocking state.

[0060] In a method step 120, the at least one valve 1 is switched from the blocking state to the forward flow state. Switching the valve 1 to the forward flow state can occur, in particular, by increasing the pressure in the corresponding media supply line 23. If, for example, the at least one pump M1...M23 is operated in compression mode and the pressure in the media supply line 23 upstream of the media applicator 21 increases such that the first threshold value is exceeded, the valve 1 opens automatically, see, for example, Figures 2 and 5 , and the medium can be applied.

[0061] In a method step 130, the at least one valve 1 is returned from the forward flow state to the basic state or blocking state. This can be done, for example, by switching off the at least one pump M1...M23. In the process, the pressure in the media supply line 23 decreases and the closing body 4 (embodiment of the Fig. 1 ) or the first closing body 4' (embodiment of the Fig. 4 ) is supported by the spring element 5 (embodiment of the Fig. 1 ) or from the first spring element (embodiment of the Fig. 4 ) back to the starting position or to the locking position.

[0062] In a method step 140, the at least one valve 1 is switched from the blocking state to the reverse flow state. This can be done, in particular, by operating the at least one pump M1...M23 in the suction mode. In this case, a negative pressure can be generated in the media supply line, in particular relative to the pressure in the valve outlet, so that the pressure difference falls below the second threshold value. The valve thus opens quasi-automatically due to the pressure change in the media supply line, cf., for example, Figures 4 and 6 above, and the medium can flow back to the media supply unit 24.

[0063] The Fig. 8The method steps 110 to 140 shown can, in particular, be performed repeatedly or multiple times. For example, the at least one valve 1 can be repeatedly switched to the return flow mode, in particular when a media change and / or a system shutdown is pending. In this case, any media residues from the media applicator 21 or from the media supply lines can be conveyed back into the media supply unit 24.

[0064] With the media applicator or system for applying media described above, media can be applied in a particularly economical manner. In particular, the maintenance and cleaning effort of the media application systems is significantly reduced. This is because all media supply lines can be operated bidirectionally, so that the media residues are collected back into the respective media containers after each operation or after each media change. Cleaning or flushing of the media supply tract is mainly reduced to cleaning the spray head 26, which can be accomplished with relatively little effort using a dedicated cleaning device 27.

[0065] Although at least one exemplary embodiment has been shown in the foregoing description, various changes and modifications may be made. The recited embodiments are merely examples and are not intended to limit the scope, applicability, or configuration of the present disclosure in any way. Rather, the foregoing description provides those skilled in the art with a road map for implementing at least one exemplary embodiment, wherein numerous changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the appended claims and their legal equivalents. Furthermore, multiple modules or multiple products may be connected together in accordance with the principles described herein to obtain additional functions.It will be apparent to those skilled in the art that the embodiments described above are to be understood as examples and that the invention is not limited to them, but can be varied in many ways without departing from the scope of the claims. Furthermore, it is clear that the features, regardless of whether they are disclosed in the description, the claims, the figures or otherwise, also individually define essential components of the invention, even if they are described together with other features. In all figures, the same reference numerals represent the same objects, so that descriptions of objects that may only be mentioned in one or at least not with regard to all figures can also be transferred to these figures and exemplary embodiments with regard to which the object is not explicitly described in the description. List of reference symbols

[0066] 1Valve 2Valve body 3Valve channel 4Closing body, first closing body 4Second closing body 5Spring element, first spring element 5Second spring element 6Support 7First end 8Second end 9First recess 10Second recess 11Locking ring 11First locking ring 12Stem 13Foot 14Head 20System 21Media applicator 22Flow channel 22aOutlet 22eInlet 23Media supply line 24Media supply unit or media supply and recovery unit 25Pump unit 26Spray head 27Cleaning device 28Air inlet 29Rinsing agent inlet 30Rinsing line F1...F23Media tank M1...M23Pump ΔP Pressure difference P1 first threshold P2 second threshold

Claims

1. Media applicator (21) for applying media, comprising at least one flow channel (22) with an inlet (22e) for feeding in at least one medium and with an outlet (22a) for discharging the at least one medium fed in through the inlet (22e), wherein at least one valve (1) with a controllable valve state is provided in the at least one flow channel (22), and wherein the at least one valve (1) is designed such that the valve state can be switched between a blocking state, a forward flow state and a reverse flow state as required.

2. Media applicator according to claim 1, wherein the at least one valve (1) is designed such that the valve state can be controlled as a function of a current pressure difference ΔP between the inlet (22e) and the outlet (22a) of the at least one flow channel (22).

3. Media applicator according to claim 2, wherein the at least one valve (1) is designed to be switched from the blocking state to the forward flow state when the pressure difference ΔP exceeds a predefined first threshold value P1.

4. Media applicator according to claim 3, wherein the media supply line is maintained at an operating pressure and the first threshold value P1 is higher than the operating pressure, and / or wherein the first threshold value P1 is between 2 bar (abs) and 10 bar (abs), in particular between 3 bar (abs) and 9 bar (abs), especially between 4 bar (abs) and 6 bar (abs).

5. Media applicator according to one of claims 2 to 4, wherein the at least one valve is designed to be switched from the blocking state to the reverse flow state when the pressure drop falls below a predefined second threshold value P2.

6. Media applicator according to claim 5, wherein the media supply line is maintained at an operating pressure and the second threshold value P2 is below the operating pressure, in particular at least 0.1 to 0.5 bar below the operating pressure and / or wherein the second threshold value P2 is 10 bar to 2 bar, in particular between 9 bar and 3 bar, especially between 6 bar and 4 bar below the first threshold value P1, and / or wherein the second threshold value P2 is 1.5 to 0.5 bar (abs).

7. Media applicator according to one of the preceding claims, wherein the at least one valve comprises at least one closing body (4, 4') and at least one spring element (5, 5'), and wherein the at least one spring element (5, 5') is designed such that the at least one closing body (4, 4') can be held in a closed position for blocking the valve (1) by means of the at least one spring element (5, 5').

8. Media applicator according to claim 7, wherein the at least one spring element (5, 5') comprises at least one overpressure spring (5) for holding the at least one closing body (4) in the closed position until the first threshold value P1 is exceeded, and at least one negative pressure spring (5') for holding the at least one closing body (5') in the closed position until the second threshold value P2 is undershot.

9. Media applicator according to one of the preceding claims, wherein the media applicator (21) comprises a spray head (26) connected on the output side to the at least one flow channel for spraying the at least one medium.

10. A system (20) for applying media, comprising at least one media applicator (21) according to one of the preceding claims, wherein the at least one flow channel (22) of the media applicator (21) is connected via at least one media supply line (23) to a media supply unit (24) with at least one media container (F1...F23), and wherein the system (20) further comprises a pump unit (25) with a number of pumps (M1...M23) for conveying the at least one medium through the at least one media supply line (23), wherein the at least one of the pumps (M1...M23) is designed to convey the at least one medium from the media supply unit (24) towards the media applicator (21) in a first operating mode and from the media applicator (21) back towards the media supply unit (24) in a second operating mode.

11. System according to claim 10, wherein the at least one valve (1) of the media applicator (21) is designed such that the valve state can be controlled as a function of a current pressure difference ΔP between the inlet (22e) and the outlet (22a) of the at least one flow channel (22), and wherein the at least one pump (M1...M23) is designed to generate a pressure difference ΔP required to control the at least one valve.

12. Method (100) for applying media by means of a system (20) with a media applicator (21) for applying media, wherein the media applicator (21) has at least one flow channel (22) with at least one controllable valve (1), and wherein the at least one controllable valve (1) is designed such that the valve state can be switched between a blocking state, a forward flow state and a reverse flow state as required, comprising: - providing (110) the system in a basic state, wherein the at least one valve (1) is in the blocking state, - setting (120) the at least one valve (1) to the forward flow state, - setting (130) the at least one valve (1) back to the blocking state, and - setting (140) the at least one valve to the reverse flow state.

13. The method according to claim 12, wherein the at least one valve (1) is designed such that the valve state can be controlled as a function of a current pressure difference between the inlet and the outlet of the at least one flow channel, and wherein the method comprises controlling the current pressure difference ΔP for controlling the at least one valve.

14. The method according to claim 13, wherein the at least one valve (1) is configured to be switched from the blocking state to the forward flow state when the pressure difference ΔP exceeds a predefined first threshold value P1, and wherein the method comprises exceeding the first threshold value for discharging media.

15. The method according to any one of claims 11 to 14, wherein the at least one valve is configured to be switched from the blocking state to the reverse flow state when the pressure difference ΔP falls below a predefined second threshold value P2, and wherein the method further comprises falling below the second threshold value to free the system of media residues.

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