Surface treatment device and method for operating a surface treatment device

Abstract

In order to provide a surface treatment device for treating a surface of a workpiece which is operable simply and safely, it is proposed that the surface treatment device include the following: a work region in which the surface of the workpiece is treatable; a flow guiding device by means of which a gas stream is guidable through the work region; a solvent separating device for separating off solvent from the gas stream that is guided through the work region, wherein the solvent separating device is configured to be put selectively in a separating condition or in a rest condition, wherein, in the separating condition, the solvent separating device separates off solvent from the gas stream.

Claims

1. A surface treatment device for treating a surface of a workpiece, including: a work region in which the surface of the workpiece is treatable; a flow guiding device by means of which a gas stream is guidable through the work region; a solvent separating device for separating off solvent from the gas stream that is guided through the work region, wherein the solvent separating device is configured to be put selectively in a separating condition or in a rest condition, wherein, in the separating condition, the solvent separating device separates off solvent from the gas stream, wherein by means of an intake air device of the surface treatment device, an intake air stream is feedable to the flow guiding device, and wherein by means of the solvent separating device, solvent is releasable into at least one of the intake air stream or a circulating air stream that is guided through the work region.

2. The surface treatment device according to claim 1, wherein the gas stream is feedable again by means of the flow guiding device to the same work region and/or to a further work region of the surface treatment device.

3. The surface treatment device according to claim 1, wherein the surface treatment device includes a particle separating device which takes the form of a regenerable filter device, for separating off particles from a gas stream that is guided through a work region and is loaded with particles.

4. The surface treatment device according to claim 1, wherein the surface treatment device includes a control device by means of which the surface treatment device is selectively operable in a treatment operation, in which workpieces are treated, or in a rest operation, in which no workpieces are treated, wherein, in the treatment operation of the surface treatment device, the solvent separating device is in the rest condition, and wherein, in the rest condition of the surface treatment device, the solvent separating device is in the separating condition, with the result that the solvent separating device separates solvent off from the gas stream that is guided through the work region.

5. The surface treatment device according to claim 1, wherein the solvent separating device is a solvent temporary storage device by means of which solvent which, in a treatment operation of the surface treatment device, is contained in a gas stream that is to be fed to a work region is separable from the gas stream in a rest condition of the surface treatment device.

6. The surface treatment device according to claim 1, wherein the solvent separating device is a solvent temporary storage device by means of which solvent which, in a rest operation of the surface treatment device, is taken up in the solvent separating device is releasable into a gas stream that is to be fed to a work region in a treatment operation of the surface treatment device.

7. The surface treatment device according to claim 1, wherein the solvent separating device includes an adsorption device for the adsorption of solvent, a condensation device for condensing out solvent and/or a combustion device for the thermal conversion of solvent.

8. The surface treatment device according to claim 1, wherein the work region is a coating region, a drying region and/or a monitoring region for coating, drying, monitoring and/or post-treatment of workpieces.

9. The surface treatment device according to claim 1, wherein the surface treatment device includes a conditioning device by means of which an intake air stream and/or a gas stream that is guided through a work region are conditionable before being fed to a work region.

10. A method for operating a surface treatment device, wherein: a surface of a workpiece is treated in a work region of the surface treatment device; a gas stream is guided through the work region; a solvent separating device for separating solvent off from the gas stream that is guided through the work region is selectively put in a separating condition or in a rest condition, wherein, in the separating condition, the solvent separating device separates off solvent from the gas stream, wherein by means of an intake air device of the surface treatment device, an intake air stream is feedable to the flow guiding device, and wherein by means of the solvent separating device, solvent is releasable into at least one of the intake air stream or a circulating air stream that is guided through the work region.

11. The method according to claim 10, wherein the gas stream that is guided through the work region is fed again to the same work region or to a further work region of the surface treatment device.

12. The method according to claim 10, wherein, in a treatment operation of the surface treatment device, in which workpieces are treated, the solvent separating device is in the rest condition.

13. The method according to claim 10, wherein, in a rest operation of the surface treatment device, in which no workpieces are treated, the solvent separating device is in the separating condition, in which the solvent separating device separates solvent off from the gas stream that is guided through the work region.

14. The method according to claim 10, wherein the gas stream that is guided through the work region and/or that is to be fed to the same work region or a further work region is conditioned in respect of its air humidity and/or in respect of its temperature in a rest operation of the surface treatment device, in which no workpieces are treated, before and/or after the gas stream is fed to the solvent separating device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings:

(2) FIG. 1 shows a schematic vertical sectional illustration of a first embodiment of a surface treatment device, in which no exhaust air purification is provided;

(3) FIG. 2 shows a schematic illustration corresponding to FIG. 1, of a second embodiment of a surface treatment device, in which a thermal exhaust air purification device is provided for cleaning the exhaust air;

(4) FIG. 3 shows a schematic illustration corresponding to FIG. 1, of a third embodiment of a surface treatment device, which includes a thermal exhaust air purification device and a carbon fibre paper rotor device for cleaning the exhaust air;

(5) FIG. 4 shows a schematic illustration of a fourth embodiment of a surface treatment device, in which a solvent separating device is arranged upstream of a conditioning device, wherein the surface treatment device is in a treatment operation;

(6) FIG. 5 shows a schematic illustration corresponding to FIG. 4, of the fourth embodiment of the surface treatment device, wherein the surface treatment device is in a rest operation;

(7) FIG. 6 shows a schematic illustration corresponding to FIG. 4, of a fifth embodiment of a surface treatment device, in which a solvent separating device is arranged downstream of a conditioning device, wherein the surface treatment device is in a treatment operation;

(8) FIG. 7 shows a schematic illustration corresponding to FIG. 6, of the fifth embodiment of the surface treatment device, wherein the surface treatment device is in a rest operation; and

(9) FIG. 8 shows a schematic illustration corresponding to FIG. 4, of a sixth embodiment of a surface treatment device, with an alternative flow guiding device.

DETAILED DESCRIPTION OF THE DISCLOSURE

(10) Like or functionally equivalent elements are provided with the same reference numerals in all the Figures.

(11) A surface treatment device which is illustrated in FIG. 1 and is designated 100 as a whole takes the form, for example, of a coating plant 102 for coating workpieces 104, in particular vehicle bodies.

(12) To this end, the surface treatment device 100 includes a work region 108 which takes the form of a coating region 106 and to which the workpieces 104 are feedable for coating thereof.

(13) During a treatment operation of the surface treatment device 100, in which workpieces 104 are treated, in particular being coated, a gas stream, in particular an air stream, flows through this work region 108.

(14) In so doing, the gas stream flows through the work region 108 in the direction of gravity, downwards from above.

(15) The gas stream is fed to the work region 108 through a plenum 110 which is arranged above the work region 108.

(16) Below the work region 108 there is arranged a filter system 112 by means of which the gas stream that is guided through the working region 108 can be cleaned of coating overspray particles that occur during the treatment operation.

(17) To this end, the filter system 112 includes in particular regenerative filter devices in which auxiliary filter material is fed to the gas stream to be cleaned. The coating overspray particles are then separated off, together with the auxiliary filter material, at filter elements of the filter devices.

(18) The filter system 112 thus includes in particular particle separating devices 114 for separating off particles, in particular coating overspray particles.

(19) In the first embodiment of the surface treatment device 100 which is illustrated in FIG. 1, at least part of the gas stream that is cleaned by means of the filter system 112 may be released into the environment of the surface treatment device 100 by means of an exhaust air device 116.

(20) Further, it may be provided for at least part of the gas stream that is cleaned by means of the filter system 112 to be guided in a circular flow by means of a circulating air guide 118, and to be fed to the work region 108 again.

(21) Preferably, in all cases a portion of the gas stream that is guided through the work region 108 is guided away by means of the exhaust air device 116 and a portion of the gas stream that is guided through the work region 108 is fed to the work region 108 again by means of the circulating air guide 118.

(22) In order to replace the portion of the gas stream that is guided away through the exhaust air device 116, the surface treatment device 100 includes an intake air device 120.

(23) Intake air, in particular fresh air, may be fed to the work region 108 by means of the intake air device 120.

(24) The intake air device 120, the circulating air guide 118 and the exhaust air device 116 are components of a flow guiding device 122 of the surface treatment device 100.

(25) To drive the gas streams in the flow guiding device 122, in particular the gas stream that is guided through the work region 108, a circulating air stream that is guided in the circulating air guide 118, an exhaust gas stream that is guided away through the exhaust gas device 116 and an intake air stream that is fed by means of the intake air device 120, the flow guiding device 122 includes a plurality of ventilators 124.

(26) Further, the surface treatment device 100 includes two conditioning devices 126.

(27) A conditioning device 126 is preferably associated with the intake air device 120 in such a way that the intake air stream to be fed to the work region 108 can be conditioned in particular in respect of its moisture and temperature.

(28) A further conditioning device 126 is associated with the circulating air guide 118 in such a way that the circulating air stream can be conditioned in respect of moisture and temperature before being fed to the work region 108.

(29) The surface treatment device 100 that is described above operates as follows:

(30) By means of a conveyor device (not illustrated), workpieces 104, in particular vehicle bodies, are introduced into the work region 108 and are coated there.

(31) During the coating procedure, the air in the work region 108 takes up coating overspray particles.

(32) To prevent undesired contamination of the work region 108 and/or the workpieces 104 with coating overspray, the air in the work region 108 is guided away. In particular, a gas stream is guided through the work region 108.

(33) The gas stream that is guided through the work region 108 is a mixture of an intake air stream that is fed in by means of the intake air device 120 and has been conditioned by means of the conditioning device 126 of the intake air device 120, and a circulating air stream that has already been guided through the work region 108 previously and has been cleaned by means of the filter system 112 and conditioned by means of the conditioning device 126 of the circulating air guide 118.

(34) A portion of the gas stream that is guided through the work region 108 is guided away through the exhaust gas device 116, as exhaust gas stream.

(35) By using a circulating air guide 118, the surface treatment device 100 can be operated with little expenditure of energy.

(36) A second embodiment, illustrated in FIG. 2, of a surface treatment device 100 differs from the first embodiment, illustrated in FIG. 1, substantially in that a thermal exhaust air purification device 128 is associated with the exhaust air device 116.

(37) By means of the thermal exhaust air purification device 128, it is possible to render harmless solvents which are released in particular during the treatment operation of the surface treatment device 100, are taken up by the gas stream that is guided through the work region 108 and cannot be removed from the gas stream using the filter system 112, in particular converting them by chemical reaction into substances which are harmless to health.

(38) The exhaust air device 116 of the surface treatment device 100 according to the second embodiment, illustrated in FIG. 2, further includes a heat exchanger 130. By means of the heat exchanger 130, heat which arises during operation of the thermal exhaust air purification device 128 can be transmitted to the exhaust air stream before the exhaust air stream is fed to the thermal exhaust air purification device.

(39) Because the second embodiment of the surface treatment device 100 includes a thermal exhaust air purification device 128, the surface treatment device 100 can be operated in a particularly environmentally friendly manner.

(40) Otherwise, the second embodiment, illustrated in FIG. 2, of the surface treatment device 100 matches the first embodiment, illustrated in FIG. 1, in terms of structure and function, so reference is made to the description above thereof in this respect.

(41) A third embodiment, illustrated in FIG. 3, of the surface treatment device 100 differs from the second embodiment, illustrated in FIG. 2, substantially in that in addition to the thermal exhaust air purification device 128 and the heat exchanger 130 a processing device 132 for processing the exhaust air stream that contains solvent is provided.

(42) Preferably, the processing device 132 is a carbon fibre paper rotor device.

(43) The processing device 132 includes a rotary device 134 for rotating a separation element 136.

(44) Exhaust air that contains solvent may flow through the separation element 136 for example in a lower region 138, in respect of the direction of gravity, as a result of which the solvent is separated off from the exhaust air.

(45) The separation element 136 is regenerated for example in an upper region 140 of the separation element 136, in respect of the direction of gravity.

(46) To this end, heated air, in particular fresh air that has been heated by means of the thermal exhaust air purification device 128 and a heat exchanger 130, is fed to the upper region 140 of the separation element 136 such that the solvent contained in the separation element 136 is released.

(47) The air stream that is guided through the separation element 136 and is loaded with solvent is then fed to the thermal exhaust air purification device 128 such that the solvent contained therein undergoes thermal conversion and is thereby rendered harmless.

(48) The separation element 136 may be rotated by means of the rotation device 134 as required. As a result of this, the initially lower region 138 becomes the upper region 140, while the initially upper region 140 becomes the lower region 138. As a result of this, continuous exhaust air purification is possible by means of the processing device 132.

(49) Otherwise, the third embodiment, illustrated in FIG. 3, of the surface treatment device matches the second embodiment, illustrated in FIG. 2, in terms of structure and function, so reference is made to the description above thereof in this respect.

(50) A fourth embodiment, illustrated in FIG. 4, of a surface treatment device 100 differs from the first embodiment, illustrated in FIG. 1, substantially in that three work regions 108 are provided and the surface treatment device 100 includes a solvent separating device 142.

(51) The solvent separating device 142 includes for example an adsorption device 144 for adsorbing solvent, a condensation device 146 for condensing out solvents, and/or a combustion device 148 for the thermal conversion of solvent.

(52) In the fourth embodiment, illustrated in FIG. 4, of the surface treatment device 100, the flow guiding device 122 includes a plurality of valves 150 for controlling gas streams in a closed and/or open loop system.

(53) Here, the term valves 150 should be understood also to include flaps or other devices by means of which a volume of flow and/or a flow direction of a gas stream may be influenced in a specific manner.

(54) For directed control of the valves 150 in a closed and/or open loop system, a control device 152 of the surface treatment device 100 is provided.

(55) FIG. 4 illustrates the surface treatment device 100 during a treatment operation in which workpieces 104 are treated.

(56) To this end, the surface treatment device 100 includes a work region 108 that takes the form of a coating region 106, a work region 108 that takes the form of a drying region 154 and a work region 108 that takes the form of a monitoring region 156.

(57) By means of a conveyor device (not illustrated), the workpieces 104 are conveyed one after the other through the coating region 106, the drying region 154 and the monitoring region 156.

(58) During the treatment operation of the surface treatment device 100, the valves 150 are triggered and arranged such that, by means of the intake air device 120, intake air may be fed to the monitoring region 156, guided through the monitoring region 156 and fed to the solvent separating device 142.

(59) The intake air that is guided through the solvent separating device 142 is fed to the circulating air stream that is guided in the circulating air guide 118.

(60) Here, the circulating air stream is a gas stream which is guided through the work regions 108, in particular the coating region 106 and the drying region 154.

(61) In so doing, the circulating air stream can be conditioned by means of the conditioning device 126 in respect of its moisture and temperature.

(62) By means of the exhaust air device 116, it is further possible for exhaust air to be guided away out of the circulating air guide 118.

(63) During the treatment operation, illustrated in FIG. 4, of the surface treatment device 100, the circulating air stream that is guided in the circulating air guide 118 is guided past the solvent separating device 142.

(64) The solvent separating device 142 is thus in a rest condition, in which no solvent is separated off by means of the solvent separating device 142 from the gas stream that is guided through the work regions 108.

(65) Only solvents that are in the intake air stream are separated off by means of the solvent separating device 142.

(66) Because the intake air stream flows continuously through the solvent separating device 142, however, whenever the solvent content in the intake air stream is below the saturation concentration specific to the temperature and substance concerned, solvents in the solvent separating device 142 are taken up by the intake air stream and fed to the circulating air stream, in particular the gas stream that is guided through the work regions 108.

(67) During the treatment operation of the surface treatment device 100, the concentration of solvent in the circulating air stream increases over time. However, as a result of the continuous feeding in of intake air and the continuous guiding away of exhaust air, an equilibrium condition is preferably established, with a substantially constant concentration of solvent in the circulating air stream.

(68) In particular when the coating region 106 and/or the drying region 154 are to be made accessible to persons, the concentration of solvent in these work regions 108 must be sharply reduced.

(69) To this end, the surface treatment device 100 can be put into the rest operation, illustrated in FIG. 5.

(70) In this rest operation of the surface treatment device 100, both the intake air stream and the circulating air stream flow through the solvent separating device 142.

(71) Solvents in the gas stream that is guided through the work regions 108 are in this case separated off by means of the solvent separating device 142, such that the concentration of solvent in the gas stream that is guided through the work regions 108, in particular the circulating air stream, can be sharply reduced within a short time.

(72) Thus, in the rest operation of the surface treatment device 100 the solvent separating device 142 is in the separating condition.

(73) With a surface treatment device 100 that has a circulating air motion comprising 10 to 20% fresh air and exhaust air portion and using the solvent separating device 142, in particular this allows the coating region 106 and the drying region 154 to be made accessible to persons in a shorter time than with a surface treatment device 100 that has a circulating air motion comprising 10 to 20% fresh air and exhaust air portion without the solvent separating device 142. Preferably, access is possible after up to 80% of the time, particularly preferably after up to 50% of the time.

(74) As a result of this, a burdensome procedure of flushing the work regions 108 with fresh air and the burdensome disposal of the circulating air stream that contains solvent can preferably be avoided.

(75) The fourth embodiment, illustrated in FIGS. 4 and 5, of the surface treatment device 100 may further be restored to the treatment operation in a particularly simple manner by suitable control of the valves 150.

(76) The solvent that is taken up in the solvent separating device 142 is then released, in the treatment operation, into the gas stream to be fed to the work regions 108 by means of the intake air that is guided through the solvent separating device 142.

(77) In this way, the gas stream to be fed to the work regions 108 and thus also the circulating air stream re-attain the process parameters prevailing in the treatment operation particularly quickly, and in particular this enables the solvent content in the circulating air stream to be brought into the equilibrium condition particularly quickly.

(78) By means of the solvent separating device 142, in the fourth embodiment, illustrated in FIGS. 4 and 5, of the surface treatment device 100 solvent can thus be put into temporary storage in order to make the work regions 108 accessible quickly.

(79) The solvent separating device 142 is thus a solvent temporary storage device 158.

(80) In particular, by means of a solvent temporary storage device 158 of this kind, the clearance time of the work regions 108, until which it is possible to give persons access, may be sharply reduced.

(81) In the fourth embodiment, illustrated in FIGS. 4 and 5, of the surface treatment device 100, in the rest operation of the surface treatment device 100 the solvent separating device 142 is arranged upstream, as seen in the direction of flow, of a conditioning device 126 for conditioning the circulating air stream. Thus, in the rest operation of the surface treatment device 100 the intake air stream is guided, together with the circulating air stream, first through the solvent separating device 142 and then through the conditioning device 126.

(82) Further, in the fourth embodiment of the surface treatment device 100, it may be provided, in the treatment operation of the surface treatment device 100, for the intake air stream to be fed partly to the solvent separating device 142 and partly directly to the circulating air guide 118.

(83) Otherwise, the fourth embodiment, illustrated in FIGS. 4 and 5, of the surface treatment device 100 matches the first embodiment, illustrated in FIG. 1, in terms of structure and function, so reference is made to the description above thereof in this respect.

(84) A fifth embodiment, illustrated in FIGS. 6 and 7, of a surface treatment device 100 differs from the fourth embodiment, illustrated in FIGS. 4 and 5, substantially in that, in the rest operation of the surface treatment device 100, the solvent separating device 142 is arranged downstream, as seen in a direction of flow of the circulating air stream, of the conditioning device 126 for conditioning the circulating air stream.

(85) The intake air that is fed by means of the intake air device 120 is in this case fed to the gas stream that is guided in the circulating air guide 118 between the conditioning device 126 for the circulating air and the solvent separating device 142, when the surface treatment device 100 is in the rest operation (see FIG. 7).

(86) In the case of the fifth embodiment, illustrated in FIGS. 6 and 7, of the surface treatment device 100, the intake air that is fed by means of the intake air device 120 is not conditioned by means of the conditioning device 126 for the circulating air, either in the treatment operation or in the rest operation.

(87) Otherwise, the fifth embodiment, illustrated in FIGS. 6 and 7, of the surface treatment device 100 matches the fourth embodiment, illustrated in FIGS. 4 and 5, in terms of structure and function, so reference is made to the description above thereof in this respect.

(88) A sixth embodiment, illustrated in FIG. 8, of a surface treatment device 100 differs from the fourth embodiment, illustrated in FIGS. 4 and 5, substantially in that, in the rest operation, the intake air stream is fed to the circulating air guide 118 downstream of the solvent separating device 142 and hence past the solvent separating device 142.

(89) In this case, the volume of flow or mass flow of the air loaded with solvent which is guided through the solvent separating device 142 can be controlled in a closed and/or open loop system in a directed manner by way of the position of the valves 150. The intake air that is fed by means of the intake air device 120, in particular fresh air, does not then result in a dilution of the gas stream to be guided to the solvent separating device 142, in particular the circulating air stream, in the rest operation of the surface treatment device 100. As a result, the residence time in the solvent separating device 142 of the gas stream that is loaded with solvent is lengthened and the separating procedure is made more efficient.

(90) Preferably, the exhaust air stream is guided away out of the circulating air guide 118 downstream of a particle separating device 114.

(91) Otherwise, the sixth embodiment, illustrated in FIG. 8, of the surface treatment device 100 matches the fourth embodiment, illustrated in FIGS. 4 and 5, in terms of structure and function, so reference is made to the description above thereof in this respect.

(92) In further embodiments (not illustrated), it may be provided for individual or a plurality of features of the embodiments described above to be combined with one another. For example, the fourth embodiment according to FIGS. 4 and 5 may be provided with a thermal exhaust air purification device 128 according to the second embodiment, illustrated in FIG. 2, of the surface treatment device 100.

(93) As a result of using a solvent separating device 142 which is configured to be put selectively in a separating condition or a rest condition, solvent may selectively be separated off from the gas stream that is guided through the work region 108 or preferably released thereto. As a result, the surface treatment device 100 is operable simply and safely.