CONVEYING DEVICE HAVING A Flushing DEVICE AND METHOD FOR OPERATING THE CONVEYING DEVICE

Abstract

The invention relates to a conveying device with a flushing device and a method for operating the conveying device. The conveying device with a flushing device according to the invention comprises a material conveyor (1) for conveying a coating material (31). The material conveyor (1) in turn has an inlet valve (7), which comprises a valve inlet (7.1) and a valve outlet (7.9). The material conveyor (1) further has a conveyor inlet (1.1) for the coating material (31), which conveyor inlet is or can be connected to the valve inlet (7.1). The conveying device further comprises a rinsing agent conveyor (3) for conveying a rinsing agent (30), which rinsing agent conveyor is likewise connected to the valve inlet (7.1).

Description

Technical Field

[0001] The invention relates to a conveying device having a flushing device and a method for operating the conveying device.

[0002] To coat a workpiece with a coating material, the coating material is transported from a storage container to a sprayer via a conveyor device and then sprayed onto the workpiece via the sprayer. The coating material can be, for example, a varnish, an adhesive, or an emulsion containing zinc powder. When the coating is completed or the coating material is to be replaced, the conveyor device, the material guide lines, and the sprayer should be cleaned or flushed separately. To this end, the coating material is replaced with a flushing medium. The flushing medium can be, for example, a flushing gas (e.g., compressed air or nitrogen), a flushing agent (e.g., a solvent or water), or a mixture of a flushing gas and a flushing agent. Background Art

[0003] A coating agent pump and a cleaning method for a coating agent pump are known from prior art EP 2 956 242 B1. The coating agent pump comprises a supply line and a pump inlet connected thereto, via which coating agent is supplied to the pump. The pump inlet is connected to the pump chamber via a check valve. During conveying operation, the coating material is sucked into the pump chamber via the pump inlet and the check valve, and subsequently pushed out of the pump outlet. The pump also comprises a blow-out port, via which compressed air is supplied to the pump. The blow-out port is also connected to the check valve. During cleaning operation, compressed air is blown through the check valve, and the coating material is thus blown out of the pump chamber in the direction of the pump outlet. The shortcoming of this solution is that the material guiding assembly (e.g., supply line) upstream of the coating material pump is not cleaned. Therefore, the supply line must be cleaned separately. Summary of the Invention

[0004] One object of the present invention is to provide a conveying device with a flushing device, in which case, in addition to the conveying device, material-conducting components upstream thereof, such as supply lines, can also be cleaned by the flushing device.

[0005] A further object of the present invention is to provide a method for operating a conveyor installation which is particularly time-saving.

[0006] An operator can advantageously bring the conveyor device according to the invention from the conveying mode into the cleaning mode particularly easily.

[0007] Another advantage is that the need for rinsing agent for each color change can be significantly reduced. The disposal costs of the waste material (mixture of coating material and rinsing agent) can also be reduced.

[0008] This object is achieved by a conveyor device with a flushing device having the features specified in claim 1 .

[0009] The conveying apparatus with a flushing device according to the present invention includes a material conveyor for conveying a coating material. The material conveyor further includes an inlet valve having a valve inlet and a valve outlet. The material conveyor further includes a conveyor inlet for the coating material, which is or can be connected to the valve inlet. The conveying apparatus also includes a flushing agent conveyor for conveying a flushing agent, which is also connected to the valve inlet.

[0010] Advantageous further developments of the invention result from the features specified in the dependent claims.

[0011] In one embodiment of the conveying device according to the present invention, the inlet valve is designed as a non-return valve. This ensures that the fluid can flow unimpeded in one direction, while backflow (and therefore flow in the opposite direction) is automatically prevented. This is achieved by a return spring in the non-return valve, which ensures that the non-return valve closes automatically. This improves the efficiency of the conveying device and the application system and minimizes the risk of damage caused by backflow.

[0012] In another embodiment of the conveying device according to the present invention, the inlet valve is designed as a disk valve, a ball valve, or a needle valve. The use of a disk valve is particularly advantageous because it can be designed so that it can be optimally flushed. It can also handle high flow rates. Furthermore, it offers a simple, reliable design and low maintenance costs.

[0013] In the case of additional embodiments of the conveying device according to the present invention, the material conveyor is designed as a bellows pump, a diaphragm pump, a centrifugal pump, a gear pump, a peristaltic pump, a piston pump, a piston dosing system, or a positive displacement pump. Which embodiment of the material conveyor is most suitable depends on the application. The most suitable material conveyor can be selected depending on the application.

[0014] In another embodiment of the delivery device according to the invention, the rinsing agent conveyor is connected to the valve inlet via a non-return valve. In this way it is ensured that no coating material enters the rinsing agent line.

[0015] The non-return valve is advantageously arranged spatially close to the valve inlet, thereby minimizing dead spaces.

[0016] In a further development of the conveying apparatus according to the invention, a shutoff device is provided, which is connected to the conveyor inlet on the inlet side and to the inlet valve on the outlet side. The shutoff device is thus arranged between the conveyor inlet and the inlet valve. When the shutoff device is closed, the pressure in the flushing medium increases further. Due to the increased flushing medium pressure, the conveying chamber, as well as the downstream material lines and components connected to the conveying chamber, can be better cleaned. Without the shutoff device, most of the flushing medium would be discharged through the supply line.

[0017] In another further development of the conveying device according to the invention, there is a control which is formed and can be operated in such a way that it controls the shut-off device. This provides for user-friendly use of the conveying device.

[0018] In the case of an additional further development, the delivery device according to the invention has a compressed gas source which can be connected to the valve inlet.The use of compressed gas as flushing medium or as an additive in the flushing medium can significantly save flushing agent.

[0019] In a further development, the delivery device according to the invention comprises a compressed gas valve, via which compressed gas from a compressed gas source can be mixed into the flushing agent. This results in a mixture of flushing agent and gas, referred to as flushing medium, which achieves a very high cleaning effect due to the high flow rate and turbulence.

[0020] Flushing with the flushing medium can be performed continuously, discontinuously or in a pulsed manner. When compressed air is mixed into the flushing agent in pulses via a clocked valve and has a higher pressure than the flushing agent, the flushing agent flow is intermittently interrupted.

[0021] In the case of the delivery device according to the invention, the flushing agent delivery device is advantageously connected to the inlet valve via a flushing line. The compressed gas source is also connected to the flushing line via a non-return valve. Without this non-return valve, flushing agent could potentially enter the compressed gas line from the flushing line.

[0022] It is also proposed that the conveyor system according to the present invention has an additional shutoff device, which is connected on the outlet side to the conveyor chamber inlet and on the inlet side to the flushing agent conveyor. This embodiment can be operated without a shutoff device upstream of the valve inlet. Consequently, flushing of the conveyor system can also be performed without a shutoff device.

[0023] In the case of the delivery device according to the invention, a flushing agent control valve can additionally be provided, which is designed and operable in such a way that it controls whether the flushing agent flows to the valve inlet or to the delivery chamber inlet. With this embodiment, the delivery device and the supply line can be flushed in an advantageous manner.

[0024] In the case of a flushing agent control valve, flushing of the delivery device and the supply line takes place one after the other. The flushing agent control valve can also be formed and operated such that the delivery device and the supply line are flushed simultaneously.

[0025] Another embodiment of the delivery device according to the invention comprises a first compressed gas valve which is connected to the flushing agent line on the output side and which, in the open state, delivers the first compressed gas volume flow rate In addition, there is a second compressed gas valve which is connected to the flushing agent line on the output side and which, in the open state, conducts the second compressed gas volume flow The compressed gas is directed into the flushing agent line. Thus, the pressure or volume flow of the compressed gas can be individually adjusted to suit the respective process step. It is advantageous, for example, to evacuate the supply line with a reduced air pressure or a throttled volume flow in order to prevent contamination at the end of the supply line when discharging the coating material.

[0026] In one embodiment of the conveying device according to the invention, there is a cam control via which the compressed gas valve can be controlled. This provides process reliability and an optimized process with good operability.

[0027] To set the first compressed gas volume flow For example, a throttle valve can be provided in the compressed gas line leading to the flushing line. The compressed gas line can be connected directly to the flushing line, thus bypassing the throttle valve. At the start of flushing, the volume flow in the sections to be flushed is still low, as there is still viscous or even highly viscous material in these sections that is only gradually pushed out. Later, when there is hardly any viscous material left in the sections to be flushed, the volume flow is higher. The volume flow can be limited via the throttle valve so that the volume flow in the supply line (inlet hose) does not become too high. This prevents material from gushing out of the supply line.

[0028] Another embodiment of the conveying device according to the present invention includes a squeeze valve, which is designed and operable to open or close the conveyor inlet. The squeeze valve provides an effective seal because the hose or line is squeezed together to prevent throughflow. This is particularly advantageous when conveying abrasive or viscous media. Due to its simple construction and lack of moving parts, the squeeze valve is low-maintenance and provides reliable performance over a long operating period.

[0029] An application system is also proposed, comprising the above-described delivery device and an applicator connected to the delivery device. This makes it possible to extend the advantages of the flushing method to the supply line of the applicator and to the applicator itself.

[0030] In the case of the method for operating the above-mentioned conveying device according to the present invention, the downstream side of the conveying device is closed to flush the supply line. This can be achieved, for example, by a valve. The flushing agent is then conveyed into the supply line by means of a flushing agent conveyor.

[0031] In order to flush the first delivery chamber, the downstream side of the delivery device is opened and the flushing agent is delivered into the first delivery chamber by means of the flushing agent conveyor. Therefore, the upstream side of the delivery device should be closed, for example via a valve or by a shut-off device.

[0032] Due to the optimal sequence of the flushing programs, a time-saving and flushing medium-saving flushing process can thus be carried out with a high level of material recovery and high flushing agent efficiency.

[0033] In a further development of the method according to the invention, flushing is performed in a pulse-like manner. Whether flushing is performed in a pulse-like manner or continuously, and whether a mixture of compressed gas and flushing agent is used or only the flushing agent is used, depends on the material to be flushed. In one case, a pulse method can thus be more effective, while in another case, flushing with a mixture of compressed gas and flushing agent can be more effective. Since the presented embodiments provide different flushing methods, the most effective method can always be selected.

[0034] In the case of a further development of the method according to the invention, compressed gas is discharged by means of the first compressed gas valve at a first compressed gas volume flow rate when the compressed gas valve is opened. When the compressed gas is to be directed to the conveyor chamber, a second compressed gas volume flow is set by means of a second compressed gas valve. Thus, unnecessary contamination due to compressed gas escaping from the supply line can be prevented.

[0035] The aforementioned actuation of the valve can be performed manually (i.e., by hand) or automatically via a control. Therefore, automatic control of the valve can also be achieved via the control. The control can also be used to control or regulate other components individually. For example, this could be the pump pressure of a material conveyor. The drain valve for the discharge line in the case of a filter and the drain valve for the discharge line in the case of a sprayer can also be controlled via the control. If desired, the application system can be further automated. Thus, changing the container or lifting the inlet hose from the container can also be automated. In this regard, manual intervention can also be omitted in cleaning mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present invention will be further explained using several exemplary embodiments based on six figures.

[0037] Figure 1A possible embodiment of the lower section of a material conveyor is shown in a three-dimensional view.

[0038] Figure 2 The lower section of the material conveyor is shown in longitudinal section.

[0039] Figure 3 The general layout of a first embodiment of an application system with a material conveyor is shown in a block diagram.

[0040] Figure 4 The general layout of a second embodiment of an application system with a material conveyor is shown in a block diagram.

[0041] Figure 5 The general layout of an embodiment of a cam control for setting a material conveyor operating mode is shown.

[0042] Figure 6 A control panel is shown, via which the operating mode of the material conveyor can be set. DETAILED DESCRIPTION

[0043] exist Figure 1 and Figure 2 A first possible embodiment of the lower section (suction side) of the material conveyor 1 is illustrated in . This suction side section of the material conveyor 1 will also be referred to as inlet duct 1 .7 in the following. Figure 1 and Figure 2 The lower part of the compressor stage 1.8 is also shown in . The coating material conveyor 1 will also be referred to in the following as simply material conveyor or conveyor. The material conveyor 1 is preferably a component of an application system. Figure 3 The general layout of a first embodiment of an application system is illustrated in FIG. The application system is provided for conveying the coating material 31 from the storage container 22 via a supply line 9. The storage container 22 is also referred to as a material storage container or a container for coating material. In short, the material conveyor 1 conveys the coating material 31 or material out of the storage container 22 and to the applicator 45. From there, it can be applied to the workpiece (not shown in the figure). The applicator 45 can be, for example, a manually actuable spray gun. Automatically actuable spray guns are not excluded. There can also be several spray guns, which are connected to the material conveyor 1.

[0044] The material conveyor 1 can be formed, for example, as a bellows pump, a diaphragm pump, a centrifugal pump, a gear pump, a peristaltic pump, a piston pump, a piston dosing system or a positive displacement pump. Figures 1 to 4 The material conveyor shown is a piston pump driven by a pneumatic motor. Instead of a pneumatic motor, an electric motor or a hydraulic motor can also be used to drive the piston 1.4. The electric motor is preferably a servomotor.

[0045] The material conveyor 1 comprises an inlet 1.1 for the coating material, or, more simply, a material inlet or conveyor inlet, to which a supply line 9 is connected. The supply line 9 can be formed, for example, as a pipe or hose and is provided for guiding the coating material 31 from a storage container 22 to the material conveyor 1. The material inlet 1.1 can be closed by means of a shut-off device 1.5. The shut-off device 1.5 is preferably formed as an extrusion valve. The extrusion valve 1.5 is controlled via a control connection 1.6. When compressed air is applied to the control connection, an extruder in the extrusion valve 1.5 expands and closes a channel 1.9 behind the inlet 1.1. In the depressurized state, the extruder in the extrusion valve 1.5 is relaxed, and the channel 1.9 is open.

[0046] Depending on the need, the shut-off device 1.5 can be actuated automatically or manually. For example, the shut-off device 1.5 can be electrically controlled (not shown) or pneumatically controlled (see Figure 3 and Figure 4 ). The squeeze valve 1.5 is preferably made of solvent-resistant rubber.

[0047] The material conveyor 1 further comprises an inlet valve 7 having a valve inlet 7.1 and a valve outlet 7.9 and a valve disc 7.7 located therebetween. In the closed state, the valve disc 7.7 rests on the valve seat 7.2. The inlet valve 7 is preferably designed as a self-closing valve. For this purpose, the inlet valve 7 can have a return spring 7.8 (see Figure 2 ), which ensures that the inlet valve 7.7 is closed in the pressure-free state. It is also advantageous if the inlet valve 7 is designed as a non-return valve. The inlet valve 7 is preferably installed in the material conveyor 1 so that it closes the conveyor inlet 1.1 when the first conveyor chamber 1.11 is pressurized. The inlet valve 7 ensures that the coating material 31 can only flow in one direction, namely in the direction of the sprayer 45. The inlet valve 7 is preferably designed to have the smallest possible dead zone. This has the advantage that only a small amount of coating material can be deposited there, thereby minimizing the risk of color spread in response to the color change. The inlet valve 7 is preferably designed as a disk valve, because disk valves have a particularly small dead zone.

[0048] When the inlet valve 7 is closed, the flushing agent inlet 1 .2 is preferably also connected to the valve inlet 7 . 1 .

[0049] When the shut-off device (squeeze valve) 1.5 is open, the conveyor inlet 1.1 is connected to the valve inlet 7.1. When the squeeze valve 1.5 is closed, the conveyor inlet 1.1 is not connected to the valve inlet 7.1. Therefore, the conveyor inlet 1.1 can be connected to the valve inlet 7.1 by means of the squeeze valve 1.5.

[0050] The material conveyor 1 also has a flushing agent inlet 1.2 for a flushing medium / flushing agent 30. The flushing agent 30 can be sucked in from the storage container 20 via a flushing line 32 and can be conveyed to the valve inlet 7.1 via a flushing line 33, a check valve 24, a flushing line 34, a check valve 8, and a flushing line 35. The flushing medium can be, for example, a solvent, water, air, or a mixture thereof.

[0051] The non-return valve 8 is preferably arranged in the direct vicinity of the valve inlet 7.1 (see Figure 2 It comprises an inlet 8.1 and an outlet 8.9, with a valve disc 8.7 therebetween. Inlet 8.1 of the check valve 8 simultaneously forms the flushing agent inlet 1.2 for the material conveyor 1. The check valve 8 is preferably designed to be self-closing. To this end, it may have a return spring 8.8, which ensures that the check valve 8 is closed in the non-pressurized state.

[0052] Material conveyor 1 also includes a second conveyor chamber 1.12, which is connected or connectable to first conveyor chamber 1.1 via a check valve 1.14. When piston 1.4 is moved upward, the volume of second conveyor chamber 1.12 decreases, and the coating material present therein is pushed out of conveyor outlet 1.3 and into material line 42. A filter 44 may be located between material line 42 and material line 43. The coating material can be discharged via discharge valve 41 into residue container 21 or returned to storage container 22.

[0053] like Figure 3 and Figure 4 As shown, a control unit 2 can be provided to control the material conveyor 1 and the flushing agent conveyor 3. The control unit 2 includes a control valve 13, which is connected to a compressed gas source 10 via a line 39 and a shutoff valve 11 on the inlet side. The compressed gas source 10 provides compressed gas at a defined pressure. For example, the compressed gas can be compressed air or nitrogen. When the control valve 13 is opened, the compressed gas reaches the control input 1.6 of the extrusion valve 1.5 via the control line 36.

[0054] The control 2 also includes a compressed gas valve 14, which is connected to the compressed gas source 10 via a flow reducer 18, a compressed gas valve 12, and a shutoff valve 11 on the inlet side. When the compressed gas valve 14 is actuated, compressed gas is supplied to the flushing line 34 via the flow reducer 17, the compressed gas line 37, and the check valve 23. For example, the flow reducer 17 may be a throttle valve or a screen. The flow reducer 18 is provided to adjust the flow rate of the compressed gas.

[0055] As a safety valve, the compressed gas valve 12 serves the purpose of preventing the system operator from accidentally actuating one of the valves 14, 15 or 16 and thus allowing flushing medium to enter the material conveyor 1 during conveying operation. Switching to the cleaning mode is only possible when the compressed gas valve 12 is actuated. The compressed gas valve 12 is optional.

[0056] The control 2 also has a compressed gas valve 15, which is connected to a compressed gas source 10 via a flow reducer 18, a compressed gas valve 12 and a shut-off valve 11 on the inlet side. When the compressed gas valve 15 is actuated, compressed gas is supplied to the flushing line 34 via a compressed gas line 37 and a non-return valve 23.

[0057] When the compressed gas valve 14 is actuated, the compressed gas is opened at a first pressure or a first compressed gas volume flow rate. is introduced into the flushing line 34. In contrast, when the compressed gas valve 15 is actuated, the compressed gas is introduced at a second pressure or a second compressed gas volume flow rate. is introduced into the flushing line 34 .

[0058] Furthermore, the control 2 has a flow valve 16 which is connected to the compressed gas source 10 via the compressed gas valve 12 and the shut-off valve 11 on the inlet side. When the flow valve 16 is actuated, compressed gas is supplied to the flushing agent conveyor 3 via the compressed gas line 38 and the flow reducer 25 in order to drive the latter.

[0059] In a preferred embodiment, the control 2 further comprises a cam control 60, by means of which the valves 13, 14, 15 and 16 can be actuated. The principle of a possible embodiment of the cam control 60 is described in Figure 5 The cam control 60 has a cam shaft 61 that can rotate about its longitudinal axis and has a plurality of cams, wherein Figure 5 Only cams 61.1, 61.2, ..., 61.8 can be seen. Figure 5 In the case of the exemplary embodiment of the embodiment, the camshaft 61 can rotate in 7 different positions 0-6 (see arrows). When the camshaft 61 is in position 0, the conveying device enters the conveying mode. In position 0, the control valve 13 or one of the compressed gas valves 14 and 15 or the flow valve 16 is not actuated by the cam. Valves 13-16 are closed. For example, if the camshaft 61 is brought to position 4, the compressed gas valve 15 and the flow valve 16 are actuated via cam 61.7. Valves 15 and 16 are thereby opened. The control valve 13 is additionally actuated (opened) via cam 61.6. In position 2, the control valve 13 and the compressed gas valve 15 are actuated by cams 61.2 and 61.4, i.e., are opened. In position 1, the compressed gas valve 14 is actuated by cam 61.3.

[0060] In accordance with Figure 4 In the case of the application system, the coating material conveyor 1 has a conveying chamber inlet 1.13, which is connected to the flushing agent control valve 51 via a flushing agent line 48 and a non-return valve 47. The flushing agent inlet 1.2 is also connected to the flushing agent control valve 51. The control valve 13 (different from Figure 3 ) It is now controlled via the flushing agent control valve 51 whether the delivery chamber inlet 1 . 13 or the flushing inlet 1 . 2 is supplied with flushing agent 30 .

[0061] Conveying mode

[0062] To put the application system into delivery mode, the system operator turns the knob 71 on the control panel 70 (see Figure 6 ) until the knob 71 points to the pictogram 72 with a spray gun. Then, the cam shaft 61 connected to the knob 71 is in position 0. The application system is now in delivery mode. Once the system operator actuates the trigger lever on the sprayer 45, the coating material 31 is sprayed.

[0063] When knob 71 points to pictogram 72, this has the effect of camshaft 61 of cam control 60 bringing valves 13, 14, 15, and 16 into the blocked state. Consequently, no compressed gas enters control line 36 and compressed gas lines 37 and 38. Due to the fact that control line 36 is depressurized, shutoff device (extrusion valve) 1.5 is opened, allowing coating material 31 to reach valve inlet 7.1 via coating material supply line 9. When piston 1.4 now moves upward, coating material 31 is sucked out of storage container 22 and, via supply line 9, inlet 1.1, valve inlet 7.1, and through inlet valve 7, into first delivery chamber 1.11. Check valve 1.14 is thereby closed, i.e., blocked.

[0064] The coating material already in second delivery chamber 1.12 is pushed out of it by piston 1.4 and transported to sprayer 45 via material line 42, filter 44, and material line 43. Once piston 1.4 reaches its top dead center, inlet valve 7 closes, closing the inlet side of first delivery chamber 1.11. When piston 1.4 subsequently moves downward, coating material 31 is pushed out of first delivery chamber 1.11, passing through check valve 1.14 and into second delivery chamber 1.12. Piston 1.4 then moves upward again, and the above process repeats itself.

[0065] In the case of a conveying device, different pressures such as pump pressure, spraying pressure, circulation pressure, filling pressure and / or cleaning pressure can be set or regulated individually.

[0066] The pump pressure is the pressure at which the coating material 32 appears at the conveyor outlet 1.3. It can be set in conveying mode. The spraying pressure is the pressure at which the coating material 31 is sprayed onto the workpiece. The circulation pressure is the pressure at which the material 31 circulates in the conveying device via the discharge valve. The circulation pressure is generally lower than the spraying pressure. The filling pressure is the pressure at which the material conveyor 1 is filled with coating material 31. The filling pressure is generally lower than the spraying pressure. The cleaning pressure is the pressure of the flushing medium used to clean the material conveyor 1 (before switching to cleaning mode). The cleaning pressure is generally lower than the spraying pressure.

[0067] Cleaning Mode

[0068] Position 1: Drain supply line 9 (inlet hose)

[0069] To put the application system into cleaning mode from the delivery mode, the system operator turns the knob 71 on the control panel 70 to the cleaning position (position 1). In this position, the compressed gas valve 14 is actuated by the cam 61.3 of the camshaft 61 and brought into the open state. This has the effect that the compressed gas flows into the flushing line 34 via the compressed gas valve 14, the flow reducer 17, the flushing line 37 and the non-return valve 23. Due to the flow reducer 17, the compressed gas flows at a throttled volume flow rate. It enters flushing line 34. From there, it enters flushing line 35 and reaches valve inlet 7.7 via non-return valve 8. The closing force of return spring 7.8 on inlet valve 7 is preferably so great that inlet valve 7 remains closed even when air pressure is applied. Due to the fact that extrusion valve 1.5 is open, the coating material in supply line 9 is transported back with the aid of compressed gas and ultimately into residue container 21. In this way, valve inlet 7.1, extrusion valve 1.5, conveyor inlet 1.1, and supply line 9 are emptied.

[0070] Position 2: Emptying the material conveyor 1 in the direction of the spray gun

[0071] When the system operator brings the knob 71 to position 2, the control valve 13 is opened by the cam 61.2, so that the compressed air reaches the control connection 1.6 and the shut-off device 1.5 closes the channel 1.9. The compressed gas valve 15 is additionally actuated by the cam 61.4 and brought into the open state. As a result, the compressed gas flows at a second compressed gas volume flow rate. Compressed gas flows from source 10 via compressed gas valve 15 and compressed gas line 37 into flushing line 34. When the system operator actuates the trigger on the sprayer, inlet valve 7 opens because the compressed gas pressure is greater than the restoring force of return spring 7.8 in inlet valve 7.7. Flushing gas then enters first delivery chamber 1.11. From there, it flows via check valve 1.14 into second delivery chamber 1.12, then into material hoses 42 and 43, all the way to sprayer 45. Consequently, any remaining coating material is sprayed out via sprayer 45.

[0072] Alternatively, the discharge valve 46 can also be opened on the sprayer 45 so that the remaining coating material can be discharged via the line 49 into the residue container 21 or back into the storage container 22. When the flushing program is completed, the discharge valve 46 is closed again.

[0073] Alternatively, the drain valve 41 can also be opened at the filter 44 so that the remaining coating material can be drained via the line into the residue container 21 or back into the storage container 22. When the flushing program is completed, the drain valve 41 is closed again.

[0074] Position 3: Flush supply line 9 (inlet hose)

[0075] When the system operator turns the knob 71 to position 3, the valves 14 and 16 are actuated by the cams 61.1 and 61.8 on the camshaft 61 and brought into the open state. As a result, the compressed gas is discharged at a first compressed gas volume flow rate. From the compressed gas source 10, it enters the flushing line 34 via the compressed gas valve 14, the flow reducer 17, and the compressed gas line 37. The flushing agent pump 3 is also driven by compressed gas, which reaches the flushing agent pump 3 via the flow valve 16 and the line 38. The flushing agent pump now conveys flushing agent 30 from the flushing agent container 20 via the flushing agent line 32 into the flushing agent lines 33 and 34, and from there via the non-return valve 8 into the flushing agent line 35. The flushing agent then reaches the valve inlet 7.1 via the flushing inlet 1.2.

[0076] The closing force of the return spring 7.8 at the inlet valve 7 is preferably so great that the inlet valve 7 is closed even when flushing agent pressure is applied. Due to the fact that the squeeze valve 1.5 is open, the supply line 9 is flushed with compressed gas and flushing agent and ultimately into the residue container 21. The valve inlet 7.1, the squeeze valve 1.5, the conveyor inlet 1.1 and the supply line 9 are flushed in this way.

[0077] Position 4: Flushing of the material conveyor 1 in the direction of the spray gun 45

[0078] When the system operator turns the knob 71 to position 4, the valves 13, 15 and 16 are actuated by the cams 61.6 and 61.7 of the camshaft 61 and brought into the open state. This has the effect that the compressed gas reaches the control input 1.6 of the squeeze valve 1.5 via the control valve 13 and the line 36 and closes the squeeze valve 1.5. In addition, the compressed gas flows at a volume flow rate of Compressed gas from source 10 enters flushing line 34 via compressed gas valve 15 and compressed gas line 37. The flushing agent pump 3 is also driven by compressed gas, which reaches it via flow valve 16 and line 38. The flushing agent pump now delivers flushing agent 30 from flushing agent container 20 via flushing agent line 32 to flushing agent lines 33 and 34, and from there to flushing agent line 35 via check valve 8. The flushing agent then reaches valve inlet 7.1 via flushing inlet 1.2. When the system operator now activates the trigger on sprayer 45, inlet valve 7 opens because the pressure of the compressed gas (flushing gas) and flushing agent is greater than the restoring force of return spring 7.8 in inlet valve 7.7. A mixture of flushing gas and flushing agent (flushing medium) then enters first delivery chamber 1.11. From there, the mixture flows via check valve 1.14 into second delivery chamber 1.12 and subsequently into material hoses 42 and 43, flowing all the way to sprayer 43. The flushing medium is thus sprayed out via the sprayer 45 .

[0079] Alternatively, the discharge valve 46 can also be opened at the sprayer 45 so that the flushing medium can be discharged via the line 49 into the residue container 21 or returned to the storage container 22. When the flushing process is completed, the discharge valve 46 is closed again. Alternatively, the discharge valve 41 can also be opened at the filter 44 so that the flushing gas and flushing agent can be discharged via the line into the residue container 21 or returned to the storage container 22. When the flushing process is completed, the discharge valve 41 is closed again.

[0080] Position 5: Drying supply line 9

[0081] In position 5, the compressed gas valve 14 is driven by the cam of the camshaft 61 (the cam is Figure 5 The valve (not visible in FIG) is actuated and brought into the open state. This has the effect that the compressed gas is released at a first volume flow rate. It flows into the flushing line 34. From there, it enters the flushing line 35 and reaches the valve inlet 7.7 via the non-return valve 8. Due to the fact that the squeeze valve 1.5 is open, the remaining flushing agent is now blown out with the help of compressed gas via the supply line 9. In this way, the valve inlet 7.1, the squeeze valve 1.5, the inlet 1.1 and the line 9 can be dried.

[0082] Position 6: Drying material conveyor 1 in the direction of the spray gun 45

[0083] When the system operator brings the knob 71 to position 6, the control valve 13 and the compressed gas valve 15 are turned by the two cams of the cam shaft 61 (cam 61.5 and the second cam, the second cam is in the Figure 5 The control valve 13 (not visible in FIG) is activated and brought into the open state. This has the effect that the compressed gas reaches the control input 1.6 of the squeeze valve 1.5 via the control valve 13 and the line 36 and closes the squeeze valve 1.5. The compressed gas is thus supplied at a second volume flow rate Compressed gas flows from source 10 via compressed gas valve 15 and compressed gas line 37 into flushing line 34. When the system operator actuates the trigger on sprayer 45, inlet valve 7 opens because the compressed gas pressure is greater than the restoring force of return spring 7.8 in inlet valve 7.7. Flushing gas then enters first delivery chamber 1.11. From there, it flows via check valve 1.14 into second delivery chamber 1.12 and subsequently into material hoses 42 and 43, all the way to sprayer 45. Any remaining flushing agent is then ejected via sprayer 45.

[0084] Alternatively, the drain valve 46 can also be opened at the sprayer 45 so that the remaining flushing agent can be blown out via the line 49. The pressure stage 1.8 and the lines 42, 43 or components located on the downstream side of the pressure stage can be dried in this way. When the drying process is completed, the drain valve 46 is closed again.

[0085] Flushing or drying can be performed in a pulsed or continuous manner, respectively. Solvent residues in the material conveyor 1 are blown out by means of compressed air as flushing medium.

[0086] At position 4 (flushing the material conveyor 1 in the direction of the spray gun 45), it can also be advantageous to flush without compressed air, thus using only flushing agent 30. After the flushing process is complete, the material conveyor 1 can be switched off and left standing, completely or partially filled with flushing agent 30. If coating material 31 is still present in the material conveyor 1, the flushing agent 30 can now slowly dissolve any remaining material residues. This ensures that any remaining material residues do not dry out in the material conveyor 1. For this purpose, an additional on-off valve (not shown) can be installed that deactivates the compressed air valve 15.

[0087] In another embodiment, the throttle valve 26 (see Figure 4) is installed in the flushing agent line 33 between the flushing agent pump 3 and the check valve 24. The throttle valve 26 is optional. The flushing agent flow can also be throttled thereby so that not too much flushing agent 30 flows into the flushing line 34. The supply of flushing gas to the flushing line 34 can be better adjusted via the flow reducer 19, which is designed as a pressure regulating valve, for example. The flushing agent can be dispersed into fine droplets in the flushing line by the throttle valve 26, thereby achieving better mixing of the flushing gas and flushing agent.

[0088] In one embodiment of the cleaning method, first conveyor chamber 1.11 and preferably also second conveyor chamber 1.12 are emptied before flushing. This can be achieved, for example, by opening discharge valve 41 and moving piston 1.4 up and down several times. Coating material still present in both conveyor chambers 1.11 and 1.12 is thereby largely discharged via discharge valve 41.

[0089] In another embodiment of the cleaning method, the first conveyor chamber 1.11 and preferably also the second conveyor chamber 1.12 are dried after rinsing. For this purpose, the discharge valve 41 is opened and compressed gas is blown through the conveyor chambers 1.11 and 1.12.

[0090] It can happen that, in the case of the coating material conveyor 1, only the two conveyor chambers 1.11 and 1.12 (compressor stage 1.8) are to be flushed. In this case, the shut-off device 1.5 is activated, so that the conveyor inlet 1.1 is closed. The flushing agent introduced via the flushing inlet 1.2 opens the inlet valve 7 due to the pressure, so that the flushing agent is now directed into the color stage.

[0091] In order to flush the inlet pipe 1.7, the shut-off device 1.5 is opened. The flushing agent introduced via the flushing inlet 1.2 now flows through the inlet pipe 1.7 in the direction of the supply line 9.

[0092] When it is closed, the shut-off device 1 . 5 makes it possible to build up the flushing agent pressure required for cleaning the compressor stage 1 . 8 , since it prevents the flushing agent from escaping through the supply line 9 .

[0093] When it is opened, the shut-off device 1 . 5 makes it possible to direct flushing agent in the direction of the supply line 9 in order to clean the latter.

[0094] Coating material still present in the application system can be recovered since the coating material is removed from the system by means of the compressed gas.

[0095] The cleaning method may additionally comprise the following process steps.

[0096] The supply line 9 is removed from the material storage container 22 and led into the residue container 21. This ensures that no flushing agent enters the material storage container 22 during the flushing of the inlet pipe 1.7 and the supply line 9.

[0097] The material conveyor 1 can also be operated without load, because the sprayer 45 is activated and the piston 1.4 is moved up and down. The remaining coating material is conveyed out via the conveyor outlet 1.3 and sprayed via the sprayer 45.

[0098] The supply line 9 and / or the piston pump and / or the material hoses 42, 43 can also advantageously be blown out with compressed gas. This allows unused material to be recycled.

[0099] The coating material conveyor 1 and upstream components (supply line 9 etc.) can be flushed with a gas-solvent mixture. By adding gas, the consumption of solvent can be reduced.

[0100] By means of the above-described method for cleaning an application system, cleaning time can be significantly shortened.

[0101] In the case of the above method, there is no need to dismantle the system components (filter 44, housing 1.15, 1.16, 1.17 at the inlet pipe), and the manual cleaning work is thus greatly reduced.

[0102] In some applications, it may be advantageous when the material conveyor 1 remains filled with flushing agent 30 until the next use (delivering coating material).

[0103] After the material conveyor 1 and the corresponding lines no longer contain any flushing agent 30 and have optionally also been dried, the material conveyor 1 can be filled again with coating material 31. To this end, a number of piston strokes are performed to convey the coating material 31 into the conveying chambers 1.11 and 1.12. The material conveyor 1 is then ready again to convey the coating material 31 to the applicator 45.

[0104] The foregoing description of exemplary embodiments according to the present invention is for illustrative purposes only. It goes without saying that variations and modifications are possible. For example, Figures 1 to 6 The different components of the illustrated application system can also be combined with one another in a manner other than that shown in the figures.

[0105] List of Figure Numbers

[0106] 1 Material conveyor

[0107] 1.1 Inlet for coating material

[0108] 1.2 Inlet for flushing agent / flushing medium

[0109] 1.3 Conveyor outlet

[0110] 1.4 Piston

[0111] 1.5 Shut-off devices, such as squeeze valves

[0112] 1.6 Control connection of the extrusion valve

[0113] 1.7 Import pipeline

[0114] 1.8 compressor levels / color levels

[0115] 1.9 channels

[0116] 1.11 First Conveyor Room

[0117] 1.12 Second Transport Room

[0118] 1.13 Transport Room Entrance

[0119] 1.14 Check valve

[0120] 1.15 Shell on inlet pipe

[0121] 1.16 Shell on inlet pipe

[0122] 1.17 Shell on inlet pipe

[0123] 1.18 Housing of the transport chamber

[0124] 2 Controls

[0125] 3. Flushing agent conveyor

[0126] 7 Inlet valve

[0127] 7.1 Valve inlet

[0128] 7.2 Valve seat

[0129] 7.7 Valve disc

[0130] 7.8 Spring

[0131] 7.9 Valve outlet

[0132] 8 valves

[0133] 8.1 Entry

[0134] 8.7 Valve disc

[0135] 8.8 Spring

[0136] 8.9 Valve outlet

[0137] 9 Supply lines

[0138] 10 Compressed air source

[0139] 11 Shut-off valve

[0140] 12 Compressed gas valve

[0141] 13 Control valve

[0142] 14 Compressed gas valve

[0143] 15 Compressed gas valve

[0144] 16 Flow valve

[0145] 17 Flow reducer

[0146] 18 Flow reducer

[0147] 19 Flow reducer

[0148] 20 Containers for flushing agent

[0149] 21 Waste container

[0150] 22 Containers for coating materials

[0151] 23 Check valve

[0152] 24 Check valve

[0153] 25 Flow reducer

[0154] 26 Throttle valve

[0155] 30 rinse agent

[0156] 31 Coating materials

[0157] 32 flushing line

[0158] 33 Flush Line

[0159] 34 Flush Line

[0160] 35 flushing line

[0161] 36 control lines

[0162] 37 Compressed gas pipeline

[0163] 38 Compressed gas pipeline

[0164] 39 Compressed gas pipeline

[0165] 39.1 Control Lines

[0166] 39.2 Control Lines

[0167] 40 Compressed gas pipeline

[0168] 41 Discharge valve

[0169] 42 Material pipelines

[0170] 43 Material pipeline

[0171] 44 filters

[0172] 45 sprayer

[0173] 46 Discharge valve

[0174] 47 Additional shut-off devices / check valves

[0175] 48 Flush Line

[0176] 49 Flush Line

[0177] 51 Flushing line control valve

[0178] 60 Cam Control

[0179] 61 Camshaft

[0180] 61.1 Cam

[0181] 61.2 Cam

[0182] 61.3 Cam

[0183] 61.4 Cam

[0184] 61.5 Cam

[0185] 61.6 Cam

[0186] 61.7 Cam

[0187] 61.8 Cam

[0188] 70 Control Panel

[0189] 71 Knob

[0190] 72 pictograms

Claims

1. A conveying device with a flushing device, - the conveying device comprises a material conveyor (1) for conveying the coating material (31), the material conveyor (1) has an inlet valve (7) comprising a valve inlet (7.1) and a valve outlet (7.9), and the material conveyor (1) having a conveyor inlet (1.1) for the coating material (31), the conveyor inlet being connected or connectable to the valve inlet (7.1), and The delivery device has a flushing agent conveyor (3) for conveying flushing agent (30), which is also connected to the valve inlet (7.1).

2. The conveying device according to claim 1, In this case, the inlet valve (7) is formed as a non-return valve.

3. The conveying device according to claim 1 or 2, In this case, the inlet valve (7) is formed as a disk valve, a ball valve or a needle valve.

4. The conveying device according to any one of claims 1 to 3, In this case, the material conveyor (1) is formed as a bellows pump, a diaphragm pump, a centrifugal pump, a gear pump, a peristaltic pump, a piston pump, a piston dosing system or a positive displacement pump.

5. The conveying device according to any one of claims 1 to 4, In this case, the flushing agent conveyor (3) is connected to the valve inlet (7.1) via a non-return valve (8).

6. The conveying device according to any one of claims 1 to 5, A shut-off device (1.5) is provided, which is arranged between the conveyor inlet (1.1) and the inlet valve (7).

7. The conveying device according to claim 6, A control (2) is provided which is designed and operable in such a way that it controls the shutoff device (1.5).

8. The conveying device according to any one of claims 1 to 7, There is a compressed gas source (10) which can be connected to the valve inlet (7.1).

9. The conveying device according to claim 8, A compressed gas valve (14) is provided, through which compressed gas from the compressed gas source (10) can be mixed into the flushing agent (30).

10. The conveying device according to claim 8 or 9, - in this case, the flushing agent conveyor (3) is connected to the inlet valve (7) via a flushing line (34), and - In this case, the compressed gas source (10) is connected to the flushing line (34) via a non-return valve (23).

11. The conveying device according to any one of claims 1 to 10, A further shut-off device (47) is provided, which is connected on the output side to a conveyor chamber inlet (1.13) of the conveyor chamber (1.11) and on the input side to the flushing agent conveyor (3).

12. The conveying device according to claim 11, A flushing agent control valve (51) is provided, which is formed and can be operated in such a way that it controls whether the flushing agent (30) flows to the valve inlet (7.1) or to the delivery chamber inlet (1.13).

13. The conveying device according to any one of claims 1 to 12, - a first compressed gas valve (14) which is connected to the flushing agent line (34) on the output side and which, in the open state, conducts a first compressed gas volume flow into the flushing agent line (34), and A second compressed gas valve (15) is provided, which is connected to the flushing agent line (34) on the output side and, in the open state, conducts a second compressed gas volume flow into the flushing agent line (34).

14. The conveying device according to claim 13, A cam control (60) is provided, via which the compressed gas valves (14, 15) can be controlled.

15. The conveying device according to any one of claims 1 to 14, There is a squeeze valve (1.5) which is formed and can be operated in such a way that it opens or closes the conveyor inlet (1.1).

16. An application system comprising a delivery device according to any one of claims 1 to 15 and an applicator (45) connected to the delivery device.

17. A method for operating a conveyor device according to any one of claims 1 to 15, - in this case, the downstream side of the conveying device is closed to flush the conveyor inlet (1.1), and In this case, the flushing agent ( 30 ) is conveyed into the supply line ( 9 ) by means of the flushing agent conveyor ( 3 ).

18. The method according to claim 17, In this case, the flushing agent (30) is conveyed into the first conveying chamber (1.11) by means of the flushing agent conveyor (3) for flushing the first conveying chamber (1.11).

19. The method according to claim 17 or 18, In this case, the shut-off device (1.5) is closed and the inlet valve (7) is opened for flushing the first delivery chamber (1.11).

20. The method according to any one of claims 17 to 19, In this case, the flushing is performed in a pulsed manner.

21. The method according to any one of claims 17 to 20, - in this case, when the compressed gas valve (14) is opened, compressed gas is directed to the conveyor inlet (1.1) with a first compressed gas volume flow rate by means of the first compressed gas valve (14), and In this case, when the second compressed gas valve (15) is opened, compressed gas is conducted into the delivery chamber (1.11) with a second compressed gas volume flow rate by means of the second compressed gas valve (15).

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