EP3896196A1 - Method and device for surface treatment of objects - Google Patents

Abstract

The invention relates to a device for the surface treatment of objects, comprising a process basin and a pump, wherein a tubular structure is arranged in or on the process basin, which is bent over at least part of its length, the two openings from the two ends of the tubular structure are limited, point in the same direction and wherein the length of the tubular structure from one opening at one end to the other opening at the other end is a maximum of twice as long as the direct distance between the two openings from the two ends of the tubular structure, and wherein the pump is arranged within the tubular structure, the pump being a bidirectional pump which is set up to be able to change its direction of rotation.

Description

The present invention relates to a device and a method for the optimized surface treatment of objects.

Objects containing metal or made of metal as well as objects with or made of plastic must be thoroughly cleaned in advance of a surface refinement such as stainless steel pickling or the application of an anodized layer, galvanizing or electroplating in order to achieve an optimal result of the surface refinement. For this purpose, various cleaning steps are known from the prior art, which an object to be refined should generally go through one after the other.

The surface treatment of objects for the purpose of cleaning usually begins with degreasing the objects. For this purpose, these are placed in baths for a defined period of time that contain a cleaning fluid to remove grease, oil and other impurities. After the objects have been degreased, they are often immersed in a sink containing water before they are placed in a pickling basin containing hydrochloric acid for a defined period of time in the next step. This is where the Removal of unwanted buildup on the surface of objects, especially rust and scale. After the pickling, the objects are again immersed in a sink containing water and then transferred to a so-called flux basin containing, for example, zinc chloride and / or ammonium chloride to remove iron. After this pre-treatment step, the cleaned object is usually dried and is then available for the desired surface refinement.

All of the pretreatment steps mentioned are mostly carried out statically in the prior art, ie the objects to be cleaned are immersed in the respective basins in which there are still liquids, e.g. degreasing liquid, water, stain, flux liquid and / or other chemical process liquids that are necessary for the Purposes of the invention are also referred to as process fluid. A disadvantage of this static pretreatment, however, is that the respective pretreatment steps take a comparatively long time, since no or only very little material exchange takes place between the process liquid surrounding the objects and the other process liquid located in the basin.

By blowing air or compressed air into the basin, the process liquid located in it can be moved, but this leads to undesired foaming of the process liquid, which negatively affects the quality of the pretreatment. In addition, the objects to be treated are not flushed through by the air flowing past them and are therefore not optimally pretreated inside.

From the EP 3 483 304 A1 It is also known to arrange at least one pump per direction of flow in the side area of the basin in which the pretreatment takes place. At least one pump conveying in one direction of flow is therefore active, while at least one further pump conveying in the other direction of flow is inactive. The pumps generate a laminar or almost laminar flow in the pretreatment tank.

This use of pumps in a pretreatment tank has numerous advantages. The movement of the process liquid can, in particular, shorten the duration of the pretreatment, which results in a significant increase in efficiency and a great potential for savings. In this way, the pickling time can be shortened by up to 50%, for example. In addition, the surface treatment is more uniform as a result of the movement of the process fluid, which means less before the surface finishing Rework is required. Because the surface treatment in a process liquid moved by pumps leads to objects with a more uniform surface, for example in a later deposition of material on the object surface, for example a later galvanizing, fewer incorrect depositions and / or less material is required for the deposition because the surface of the objects has fewer bumps that need to be leveled out.

Nonetheless, it gets out of the way EP 3 483 304 A1 known pump systems arranged in a pretreatment basin also have disadvantages. This is because the arrangement of at least one pump per direction of flow in a pretreatment basin has the immense disadvantage of a loss of space in the basin due to the space requirements of the pumps arranged on both sides. In the case of existing pools, the use of a corresponding pump arrangement is therefore ruled out simply because of the insufficient space available in the pool. The pump arrangement is therefore only suitable for newly built pools, which can be dimensioned correspondingly larger. However, this is also disadvantageous because a larger tank also requires more process fluid, which leads to higher material or chemical and energy costs. In addition, the costs for the device itself are high, since at least one pump must be used for each direction of flow. In addition, the device is the EP 3 483 304 A1 disadvantageous that the maintenance or repair is expensive, since this can only be carried out when production is interrupted due to the arrangement of the pumps on the front sides of the basin.

the DE 10 2009 034 007 A1 describes a coating system, in particular for electrophoretic or autophoretic coating or paint deposition. The system includes a circulation device for the purpose of a more uniform coating. This has a pump arrangement which is preferably arranged outside the basin and to which a circulating volume flow of at least one bath volume of the immersion bath can be fed per hour. By feeding the circulating volume flow into the immersion bath, a strong bath flow is generated. The generation of the strong bath flow takes place here, however, in that the process liquid previously removed from the basin, after it has passed through pumps, filter devices and heat exchangers over a large distance, is returned to the basin by means of nozzles or other pressure-increasing means. Because of the great distance that the process liquid has to bridge outside the basin, this is not possible without pressure-increasing means, but it requires a comparatively high amount of energy.

Object of the invention

It is the object of the present invention to provide an alternative device and an alternative method for the optimized surface treatment of objects, which avoid the aforementioned disadvantages known from the prior art and are characterized in particular by the fact that the objects that are subjected to the surface treatment are optimal are flowed around or flowed through by process fluid.

Another object of the present invention is to show a possibility of how existing basins, in which the surface treatment was previously carried out statically, can be converted into devices according to the invention in a simple manner with only a few additional components.

Yet another object of the present invention is to provide an alternative method by which an optimal result of the surface treatment can be achieved with a comparatively short duration of the surface treatment and with a comparatively small amount of process liquid used.

General description of the invention

The invention achieves this object with the features of the claims and in particular by providing a device for the surface treatment of objects, comprising a process basin and a pump, a tubular structure being arranged in or on the process basin, which is bent over at least part of its length, the two openings delimited by the two ends of the tubular structure facing in the same direction, and wherein the length of the tubular structure from one opening at one end to the other opening at the other end is a maximum of twice as long as that direct distance between the two openings that are delimited by the two ends of the tubular structure, and wherein the pump is arranged inside the tubular structure, the pump being a bidirectional pump which is set up to be able to change its direction of rotation.

The "length of the tubular structure" here means the path through the tubular structure from one opening at one end to the other opening at the other end, ie the length of the tubular structure including all bends in it.

For the purposes of the invention, a process basin is understood to mean a basin which can be filled with process fluid and in which objects can be surface treated. Process basins can therefore in particular be basins in which cleaning and / or degreasing, pickling, rinsing, flux processing and / or another, in particular chemical, pretreatment process takes place.

A tubular structure is understood to mean an elongated hollow body with a round or oval cross section, in particular perpendicular to its central longitudinal axis. The tubular structure has in particular a central straight or slightly curved section which is flanked on both sides by two curved sections. Either the two ends of the tubular structure lie in the two curved sections spaced apart from one another or in optional further straight sections adjoining these. The tubular structure is preferably mirror-symmetrical and the two openings which are delimited by the ends of the tubular structure point in the same direction. In a preferred embodiment, the tubular structure is C-shaped. If the tubular structure is arranged on or in the immediate vicinity of an end face of the process basin, the two openings, which are delimited by the ends of the tubular structure, preferably point in the direction of the opposite end face.

According to the invention, the length of the tubular structure from one opening at one end to the other opening at the other end is a maximum of twice as long as the direct distance between the two openings which are delimited by the two ends of the tubular structure. This means that process liquid which enters the tubular structure at one end, passes it and exits the tubular structure again at the other end, does not have to travel a great distance within the tubular structure. The process liquid is preferably also only guided in an arc of 180 ° within the tubular structure, for example in a C-shaped arc. Because the process fluid in the tubular structure does not have to travel a great distance, but enters at one end of the tubular structure and exits again at the other end of the tubular structure after passing through the pump, without having to take various detours such as in the DE 10 2009 034 007 A1 According to the invention, the process liquid can be returned to the process basin simply by flowing the process liquid into the basin after it has passed the tubular structure, ie according to the present invention no pressure-increasing means such as nozzles are required for this .

According to the invention, a bidirectional pump is arranged within the tubular structure. That is, the pump is positioned at any point within the hollow body, but preferably in the middle within the hollow body, so that its distance to the two ends of the hollow body is the same. The pipe section in which the pump is arranged preferably has a larger diameter than the remaining part of the tubular structure.

A bidirectional pump is understood to mean a pump which is set up to be able to change its direction of rotation or is set up to change its direction of rotation in each case after predetermined time intervals. A bidirectional pump arranged in the tubular structure can therefore convey the process liquid located in the tubular structure in opposite directions, depending on the setting. Preferred types of pumps are propeller pumps, centrifugal pumps, rotary lobe pumps, rotary lobe pumps, flap pumps, gear pumps, eccentric screw pumps, hose pumps and pneumatic diaphragm pumps. The flow speed of the pump arranged in the tubular structure is preferably 1.5 to 6 m / s, in particular 2 to 5 m / s and particularly preferably 3 to 4 m / s.

A particularly preferred pump is a propeller pump.

Regardless of the pump type, the pump arranged in the tubular structure of the device according to the invention is preferably an acid- and / or heat-resistant pump, which is preferably heat-resistant up to 65 ° C.

Preferably, the pump which is arranged in the tubular structure comprises or consists of polyethylene, polypropylene, polyvinyl chloride or mixtures thereof.

According to a preferred embodiment of the device according to the invention, the pump, which is arranged in the tubular structure, is set up to vary the delivery rate, in particular in a range between 10 and 180,000 L / h. The power of the pump is preferably <1 kW, more preferably even less than 800 W. This means that the pump in the device according to the invention works in contrast to other pumps that have a higher drive power and / or have a frequency converter in order to set a variable delivery range can, extremely energy-efficient. Because a frequency converter has a very high energy requirement. The one in the In contrast, the pump used according to the invention has an electronic control system and therefore does not require a frequency converter.

The process basin has two opposite long sides and two opposite end faces, the long sides generally being longer than the end faces, but in exceptional cases in which the process basin is square, they can also have the same length as the end faces.

According to one embodiment, the tubular structure with the bidirectional pump arranged therein is a bypass that is arranged on an end face of the process basin. Process liquid is conveyed through the bypass by the pump and enters the process basin at the end on which the bypass is arranged and flows in the direction of the opposite end.

It has been found that the passage of the process liquid through the tubular, curved structure, which enters the process basin at one end and flows against the opposite end, especially when objects to be treated are immersed in the process liquid, leads to a turbulent flow profile in the process basin , ie to a flow profile in which there is an exchange of substances between the individual liquid layers. In order nevertheless to avoid the occurrence of flow shadows, the pump arranged in the tubular curved structure is set up to change the direction of rotation after a period of, for example, several minutes, in particular after 5-10 minutes, 5-15 minutes or 5-20 minutes, so that the process liquid still enters the process basin at the same end face after passing through the bypass, but through the other opening of the tubular structure. In this way, the device according to the invention with the tubular structure arranged in or on the process basin and the bidirectional pump arranged in it, which is set up to change its direction of rotation after certain time intervals, enables optimal flow around or through the structure arranged in the process basin treating objects.

In embodiments in which the longitudinal sides of the process basin are significantly longer than its end faces, the device according to the invention preferably has two tubular structures, a bidirectional pump being arranged in each of the tubular structures. The tubular structures are each arranged as a bypass on the same end face or as a bypass on the opposite end faces.

Optionally, the device according to the invention also has more than two, for example 3, 4, 5 or 6 tubular structures, a bidirectional pump being arranged in each of the tubular structures. The tubular structures are preferably each arranged as a bypass on an end face of the process basin, wherein the number of tubular structures per end face can be the same or different. Alternatively, the tubular structures can also be arranged inside the basin on its end faces, the number of tubular structures per end face likewise being able to be the same or different. The bidirectional pump, which is arranged in each of the more than two tubular structures, optionally has the same properties as the bidirectional pump (s), which are arranged in a device according to the invention with only one or with two tubular structures , ie the pumps have in particular the properties mentioned above with regard to the variable delivery range, the performance, the material, the pump type and the acid and heat resistance.

In the case of an arrangement of two tubular structures on the same end face of the basin, it is preferred that the tubular structures have the same dimensions and are arranged at a distance from one another and with their longitudinal axes parallel to one another at the same level of the process basin.

In the case of an arrangement of two tubular structures on opposite end faces of the basin, it is preferred that the tubular structures have the same dimensions and are arranged with their longitudinal axes parallel to one another at the same height, the openings of the tubular structure arranged on one end face being the openings facing the tubular structure arranged on the other end face. The directions of rotation of the pumps arranged in both tubular structures are identical, so that a flow generated on one side of the process basin is deflected by the tubular structure arranged on the opposite side of the process basin and reinforced by the pump arranged in it and moved back to the opposite side .

According to one embodiment, the tubular structure with the bidirectional pump arranged in it is arranged in the device according to the invention within the process basin on or in the immediate vicinity of an end face, the openings that are delimited by the two ends of the tubular structure in the direction of the opposite one Face. In this embodiment, the tubular structure is not a bypass, ie it does not run like a bypass outside the basin and is only in fluidic communication with this, but it is arranged directly in the process basin. The tubular structure can be shaped in the same way as a bypass, in which both ends of the tubular structure point in the same direction. The tubular structure can be arranged with its longitudinal axis directly on the end face of the process basin, the ends of the tubular structure pointing in the direction of the opposite end face. Alternatively, the tubular structure can also be arranged at a small distance from an end face in the process basin, for example at a distance between the longitudinal axis of the tubular structure and the end face of the process basin of a few centimeters, in particular up to 10 cm, up to 20 cm or up to to 30 cm.

Regardless of whether the tubular structure is arranged directly on or in the immediate vicinity of an end face in the process basin, the pump arranged in the tubular structure generates a flow that emerges from the tubular structure and flows in the direction of the opposite end face, with As a result of the impact of the flow on the opposite end face and the flow against objects to be treated that are immersed in the process liquid, a turbulent flow profile is generated in the process basin, which, especially when the direction of rotation of the bidirectional pump changes occasionally, leads to an optimal flow around the treated Objects leads.

In this embodiment, the device according to the invention preferably has not just one but two tubular structures which are arranged within the process basin on or in the immediate vicinity of an end face. The tubular structures can be arranged on or in the immediate vicinity of the same end face or on or in close proximity to opposite end faces, the openings that are delimited by the two ends of each tubular structure each pointing in the direction of the opposite end face.

Similar to the previously described embodiment with two bypasses that are arranged on the same end face of the process basin, it is also preferred in this arrangement of two tubular structures on the same end face within the basin that the tubular structures have the same dimensions and are spaced from one another as well are arranged with their longitudinal axes parallel to each other at the same height.

In the case of an arrangement of two tubular structures opposite one another End faces within the basin, it is similar to two bypasses that are arranged on opposite end faces of the process basin, preferably that the tubular structures have the same dimensions and are arranged with their longitudinal axes parallel to each other at the same height, the openings of the one end face arranged tubular structure facing the openings of the tubular structure arranged on the other end face. The directions of rotation of the pumps arranged in both tubular structures are identical, so that a flow generated on one side of the process basin is deflected by the tubular structure arranged on the opposite side of the process basin and reinforced by the pump arranged in it and moved back to the opposite side .

According to one embodiment, the device according to the invention has, in addition to the at least one bidirectional pump, which is arranged within the tubular structure on an end face of the process basin, also at least two unidirectional pumps which are arranged on the end face of the process basin, which the end face with the tubular structure opposite. These unidirectional pumps are used to increase the flow generated by the bidirectional pump and are used in particular for longer process basins where there is no space for a bypass in which a bidirectional pump is available on the side on which the unidirectional pumps are arranged could be arranged, or due to the space requirement, no tubular structure should be arranged on the front side within the process basin. The two unidirectional pumps have opposite directions of rotation, whereby during the pretreatment of objects only that pump is in operation that has the same direction of rotation as the active bidirectional pump. When the direction of rotation of the bidirectional pump is changed, the previously inactive unidirectional pump starts operating, while the previously active unidirectional pump pauses until the direction of rotation of the bidirectional pump changes again.

Optionally, the device according to the invention also has a shut-off device for the pump arranged in the tubular structure. This shut-off device is set up in particular to interrupt the fluid communication between the pump and the process basin. For example, the shut-off device can comprise ball valves or other shut-off valves arranged on both sides of the pump, which can be shut off when the fluid exchange between the pump and the process basin is to be prevented, for example for maintenance work.

Further optionally, the device according to the invention also has one or more solid-state filters, also called rectifiers, which can in particular be arranged within the tubular structure or at its ends. The at least one solid-state filter serves on the one hand to protect the pump from the undesired ingress of dirt or solid bodies, since this can lead to damage to the pump. On the other hand, the solid-state filter also acts as an anti-intrusion device, which prevents the device operator from accidentally reaching into the pump. A solid-state filter is preferably arranged on each side of the bidirectional pump arranged in the tubular structure.

The device according to the invention preferably also has an overflow channel through which fats, oils and / or contaminants can be separated.

• Bereitstellen einer Vorrichtung zur Oberflächenbehandlung von Objekten, umfassend ein Prozessbecken und eine Pumpe, wobei in oder an dem Prozessbecken eine rohrförmige Struktur angeordnet ist, die zumindest über einen Teil ihrer Länge gebogen ist, wobei die zwei Öffnungen, die von den beiden Enden der rohrförmigen Struktur begrenzt werden, in die gleiche Richtung weisen und wobei die Länge der rohrförmigen Struktur von deren einer Öffnung am einen Ende zu deren anderer Öffnung am anderen Ende maximal zweimal so lang ist wie die direkte Distanz zwischen den beiden Öffnungen, die von den beiden Enden der rohrförmigen Struktur begrenzt werden, und wobei innerhalb der rohrförmigen Struktur die Pumpe angeordnet ist, wobei die Pumpe eine bidirektionale Pumpe ist, die eingerichtet ist, ihre Drehrichtung ändern zu können;
• Anordnen eines Objekts innerhalb des mit Prozessflüssigkeit befüllten Prozessbeckens;
• Umströmen lassen bzw. Durchströmen lassen des Objekts von Prozessflüssigkeit, wobei die Pumpe die Prozessflüssigkeit innerhalb der rohrförmigen Struktur in eine Richtung fördert.

The invention further relates to a method for the surface treatment of objects, comprising the steps:

• Providing a device for the surface treatment of objects, comprising a process basin and a pump, wherein a tubular structure is arranged in or on the process basin, which is bent over at least part of its length, the two openings opening from the two ends of the tubular structure are limited, point in the same direction and wherein the length of the tubular structure from one opening at one end to the other opening at the other end is a maximum of twice as long as the direct distance between the two openings from the two ends of the tubular structure Structure are limited, and the pump is arranged within the tubular structure, the pump being a bidirectional pump which is set up to be able to change its direction of rotation;
• Arranging an object within the process basin filled with process liquid;
• Allow process fluid to flow around or through the object, the pump conveying the process fluid in one direction within the tubular structure.

The process fluid used in the method according to the invention is in particular Degreasing liquid, water, stain, flux liquid or another acid or lye for (chemical) surface pretreatment of objects.

The object which is arranged within the process basin filled with process liquid can be any object, the surface of which is to be treated in a process liquid. Exemplary objects are in particular objects made of metal or plastic or objects that include metal, such as gratings and guardrails, and in particular objects containing steel or made of steel, such as steel girders or building structures of any kind. In a preferred embodiment, the objects include or consist of iron, Aluminum, zinc, steel and / or other alloys that include iron, aluminum and / or zinc, the objects optionally having a coating for protection against corrosion, in particular zinc plating, electroplating, KTL coating, anodizing, wet or powder coating .

• das Prozessbecken der verwendeten Vorrichtung zwei sich gegenüberliegende Längsseiten und zwei sich gegenüberliegende Stirnseiten aufweist, wobei die rohrförmige Struktur mit der darin angeordneten Pumpe als Bypass an einer Stirnseite angeordnet ist; und/oder
• die verwendete Vorrichtung zwei rohrförmige Strukturen umfasst, wobei in jeder der rohrförmigen Strukturen eine bidirektionale Pumpe angeordnet ist und wobei die rohrförmigen Strukturen jeweils als Bypass an derselben Stirnseite oder an sich gegenüberliegenden Stirnseiten angeordnet sind; und/oder
• die rohrförmige Struktur der verwendeten Vorrichtung innerhalb des Prozessbeckens an oder in unmittelbarer Nähe zu einer Stirnseite angeordnet ist, wobei die Öffnungen, die von den beiden Enden der rohrförmigen Struktur begrenzt werden, in Richtung der gegenüberliegenden Stirnseite weisen; und/oder
• die verwendete Vorrichtung zumindest zwei rohrförmige Strukturen aufweist, die innerhalb des Prozessbeckens an oder in unmittelbarer Nähe zu einer Stirnseite angeordnet sind, wobei die rohrförmigen Strukturen an oder in unmittelbarer Nähe zu derselben Stirnseite oder an oder in unmittelbarer Nähe zu sich gegenüberliegenden Stirnseiten angeordnet sind, und wobei die Öffnungen, die von den beiden Enden jeder rohrförmigen Struktur begrenzt werden, jeweils in Richtung der gegenüberliegenden Stirnseite weisen; und/oder
• die rohrförmige Struktur der verwendeten Vorrichtung mit der in dieser angeordneten bidirektionalen Pumpe in oder an dem Prozessbecken an einer Stirnseite angeordnet ist, wobei an der gegenüberliegenden Stirnseite des Prozessbeckens zumindest zwei voneinander beabstandete unidirektionale Pumpen angeordnet sind; und/oder
• die verwendete Vorrichtung eine Absperreinrichtung für die Pumpe, zumindest einen Festkörperfilter, der innerhalb der rohrförmigen Struktur oder an deren Enden angeordnet ist, und/oder eine Überlaufrinne umfasst.

The device used in the method according to the invention can in particular be designed as described above with reference to the device according to the invention as such, ie in particular that

• the process basin of the device used has two opposite longitudinal sides and two opposite end sides, the tubular structure with the pump arranged therein being arranged as a bypass on one end side; and or
• the device used comprises two tubular structures, wherein a bidirectional pump is arranged in each of the tubular structures and wherein the tubular structures are each arranged as a bypass on the same end face or on opposite end faces; and or
• the tubular structure of the device used is arranged within the process basin on or in the immediate vicinity of an end face, the openings which are delimited by the two ends of the tubular structure pointing in the direction of the opposite end face; and or
• the device used has at least two tubular structures which are arranged within the process basin on or in close proximity to an end face, the tubular structures being arranged on or in close proximity to the same end face or on or in close proximity to opposite end faces, and the openings delimited by the two ends of each tubular structure each pointing towards the opposite end face; and or
• the tubular structure of the device used with the bidirectional pump arranged in it is arranged in or on the process basin on one end face, with at least two spaced apart unidirectional pumps being arranged on the opposite end face of the process basin; and or
• the device used comprises a shut-off device for the pump, at least one solid-state filter which is arranged within the tubular structure or at its ends, and / or an overflow channel.

In the method according to the invention, process liquid flows around an object arranged in the process basin, preferably for a period of time t, the direction of rotation of the pump arranged in the tubular structure being subsequently changed so that the process liquid is conveyed in the opposite direction within the tubular structure. The time span t can be, for example, several minutes, in particular 5-10 minutes, 5-15 minutes or 5-20 minutes. After a further period of time t or a shorter or longer period of time, the direction of rotation of the pump is preferably changed again. The direction of rotation of the pump in the method according to the invention is particularly preferred during the treatment of objects in the process basin after each predetermined time interval, for example after each 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 , 13, 14, 15, 16, 17, 18, 19 or 20 minutes changed. In the process according to the invention, a turbulent flow of the process liquid surrounding the objects to be treated is generated, which is created in particular by changing the direction of rotation of the pump and because the flow of process liquid emerging from the tubular structure is at the end of the process basin opposite the tubular structure or strikes the objects to be treated arranged in this.

According to one embodiment of the method according to the invention, the formation of the turbulent flow in the process basin is supported by the use of unidirectional pumps which are arranged on the end face of the process basin, the end face on which the tubular structure with the bidirectional pump arranged therein is arranged , opposite. In contrast to the bidirectional pump, which can change its direction of rotation and does not pause during the surface treatment of the objects arranged in the process basin, the unidirectional pumps cannot change their direction of rotation or only change their direction of rotation for a short time, e.g. for cleaning purposes, for example to turn to flush out a blockage or the like. Unidirectional pumps can only generate a flow in one direction. It therefore, only those unidirectional pumps are active that have the same direction of rotation as the bidirectional pump.

Detailed description of the invention

• in der Figur 1 eine schematische Ansicht einer ersten Ausführungsform der erfindungsgemäßen Vorrichtung,
• in der Figur 2 eine schematische Ansicht einer zweiten Ausführungsform der erfindungsgemäßen Vorrichtung,
• in der Figur 3 eine schematische Ansicht der Ausführungsform aus Figur 2 während einer Oberflächenbehandlung von Objekten,
• in der Figur 4 eine schematische Ansicht der Ausführungsform aus Figur 2 während einer Oberflächenbehandlung von Objekten mit skizziertem Strömungsprofil,
• in der Figur 5 eine 3D-Ansicht einer dritten Ausführungsform der erfindungsgemäßen Vorrichtung,
• in der Figur 6 eine schematische Ansicht einer vierten Ausführungsform der erfindungsgemäßen Vorrichtung, und
• in der Figur 7 eine schematische Ansicht einer fünften Ausführungsform der erfindungsgemäßen Vorrichtung zeigen.

The invention will now be described in more detail by means of exemplary embodiments and with reference to the figures

• in the Figure 1 a schematic view of a first embodiment of the device according to the invention,
• in the Figure 2 a schematic view of a second embodiment of the device according to the invention,
• in the Figure 3 a schematic view of the embodiment from Figure 2 during surface treatment of objects,
• in the Figure 4 a schematic view of the embodiment from Figure 2 during a surface treatment of objects with a sketched flow profile,
• in the Figure 5 a 3D view of a third embodiment of the device according to the invention,
• in the Figure 6 a schematic view of a fourth embodiment of the device according to the invention, and
• in the Figure 7 show a schematic view of a fifth embodiment of the device according to the invention.

the Figure 1 shows a schematic view of a first embodiment of the device according to the invention for the surface treatment of objects. This comprises a process basin 1 with, in particular, a rectangular base area, which has two opposite end faces 6 and two opposite longitudinal sides 5 . In the process basin 1 there is process liquid 10, which can in particular be degreasing liquid, water, rinsing liquid, stain, flux liquid or some other acid or alkali for (chemical) surface pretreatment. On an end face 6 , the process basin 1 has a tubular structure 3 , within which a bidirectional pump 2 is arranged. The tubular structure 3 is designed as a bypass in the embodiment shown. The bidirectional pump 2, which is set up to change its direction of rotation at predetermined time intervals, is arranged in a straight central part of the bypass or the tubular structure 3 and points to both ends of the tubular structure 3, where they open into the process basin 1 , the same distance. On both sides of the arranged in the tubular structure 3 A solid-state filter 8 and a shut-off device 7 are arranged in each case on the bidirectional pump 2. The direction of flow through the bypass is indicated by the arrows at the transitions between the bypass and the process basin 1. In the state shown, the process liquid 10 therefore flows from bottom to top through the bypass, and if the direction of rotation of the pump 2 were to change in the opposite direction, ie from top to bottom, it would flow through the bypass (indicated by the dashed arrows).

the Figure 2 FIG. 11 shows a schematic view of a second embodiment of the device according to the invention for the surface treatment of objects which, in addition to the elements of FIG Figure 1 The embodiment shown also has a second bypass or a second tubular structure 3 with a bidirectional pump 2 arranged therein. As well as arranged in the first tubular structure 3 pump 2 is also set up this bidirectional pump 2 to change their direction of rotation in the same predetermined time intervals as the first bi-directional pump 2, wherein both pump 2 each have the same direction of rotation. The flow generated by the bidirectional pump 2 arranged on one end face 6 of the process basin is therefore deflected by the bypass arranged on the opposite end face 6 and amplified by the bidirectional pump 2 arranged therein.

the Figure 3 shows schematically the already in the Figure 2 Shown embodiment of the device according to the invention for the surface treatment of objects, two objects 9 to be treated immersing in the process liquid 10. The different flows within the process basin 1 are shown in the form of lines, from which it can be seen that a large part of the flow is circulated during the surface treatment of the objects 9 , the deflection of the flow at the end faces 6 of the process basin 1 in each case the oppositely arranged tubular structures 3 takes place. However, there is also an exchange of substances between the individual liquid layers, as in particular in FIG Figure 4 you can see. This was found out in experiments in which the movement of individual particles within a device according to the invention or in a method according to the invention was followed by means of a fluorescent marking. The motion of such a single particle is in the Figure 4 outlined.

the Figure 5 shows schematically a 3D view of a third embodiment of the device for surface treatment according to the invention. This comprises a cuboid process basin 1 with two opposite longitudinal sides 5 and two opposite end faces 6. On one of the end faces 6 , two tubular structures 3 are arranged, each in the form of a bypass. A bidirectional pump 2 (not shown) is arranged within each tubular structure 3 , the pumps 2 being set up to simultaneously change their directions of rotation in each case after predetermined time intervals.

the Figure 6 shows a schematic view of a fourth embodiment of the device according to the invention, in which two tubular structures 3 with bidirectional pumps 2 arranged therein are not arranged as bypasses, but within the process basin 1 on opposite end faces 6 . The tubular structures 3 are each arranged with its longitudinal axis at the respective end face 6 or at a small distance therefrom, wherein the two ends of each tubular structure 3 facing the respective other ends of the other tubular structure. 3 After passing through a tubular structure 3, the process liquid 10 in the process basin 1 is moved in the direction of the opposite end face 6 , where it is deflected when it passes through the tubular structure 3 arranged there and moved back in the direction of the other end face 6 . The bidirectional pumps 2 arranged in the two tubular structures 3 are set up to simultaneously change their direction of rotation and then to move process liquid 10 in the opposite direction through the tubular structures 3 or through the process basin 1.

Although according to the Figure 6 two tubular structures 3 are arranged in a process basin 1 , depending on the dimensions of the process basin 1 , only one tubular structure 3 with a bidirectional pump 2 arranged therein may be sufficient for carrying out the method according to the invention. Such an embodiment is in the Figure 7 in which the optional solid-state filters 8 arranged on both sides of the bidirectional pump 2 in the tubular structure 3 are also shown Figure 8 shows a schematic view of a fifth embodiment of the device according to the invention, in which a process basin 1 comprises a bypass or a tubular structure 3 on an end face 6 with a bidirectional pump 2 arranged therein. On the opposite end face 6 , the device has two unidirectional pumps 4 , which have an opposite direction of rotation and of which only one is in operation (indicated by the dashed or solid lines). These unidirectional pumps 4 function as auxiliary pumps in order to support or intensify the flow generated within the tubular structure 3 by the bidirectional pump 2. This embodiment of the device according to the invention is particularly suitable for process basins 1, in which due to the length of the process basin 1 the side opposite the tubular structure 3 a further pump is required in order to increase the flow generated by the bidirectional pump 2 , but in which there is no space outside the process basin 1 for a further tubular structure 3 in the form of a second bypass, for example because the process basin 1 stands with this end face 6 on a wall.

In summary, it can be stated that all of the above-described embodiments of the present invention are ideally suited for the surface treatment of objects, since in all embodiments a turbulent flow is generated in the process basin 1 by the at least one tubular structure 3 with the bidirectional pump 2 arranged in it, which optimally flows around the objects 9 arranged in the process liquid, with the formation of flow shadows being completely avoided by regularly changing the direction of rotation of the pump 2. In contrast to a laminar flow, there is an exchange of substances between the individual liquid layers, which has an advantageous effect on the result of the surface treatment, in particular by providing a qualitatively better, in particular more uniform surface treatment with a treatment time that is preferably up to 50% shorter than a static pretreatment is achieved.

The features of the invention disclosed in the above description, in the figures and in the claims can be essential both individually and in any combination for the implementation of the invention in its various embodiments.

Reference list:

1. 1 process basin
2. 2 bidirectional pumps
3. 3 tubular structure
4. 4 unidirectional pumps
5. 5 Long side of the process basin
6. 6 Front side of the process basin
7. 7 shut-off device
8. 8 solid state filters
9. 9 object
10. 10 process fluid

Claims (15)

Device for the surface treatment of objects, comprising a process basin (1) and a pump (2), characterized in that a tubular structure (3) is arranged in or on the process basin (1), which is bent over at least part of its length, wherein the two openings delimited by the two ends of the tubular structure (3) face in the same direction and wherein the length of the tubular structure (3) from its one opening at one end to its other opening at the other end a maximum of twice is as long as the direct distance between the two openings that are delimited by the two ends of the tubular structure (3), and the pump (2) is arranged inside the tubular structure (3), the pump (2) being a is a bidirectional pump that is set up to be able to change its direction of rotation. Device according to claim 1, characterized in that the process basin (1) has two opposite longitudinal sides (5) and two opposite end sides (6), the tubular structure (3) with the pump (2) arranged therein as a bypass on one Front side (6) is arranged. Device according to one of claims 1 or 2, characterized in that it comprises two tubular structures (3), wherein a bidirectional pump (2) is arranged in each of the tubular structures (3) and wherein the tubular structures (3) each act as a bypass are arranged on the same end face (6) or on opposite end faces (6). Device according to Claim 1, characterized in that the tubular structure (3) is arranged within the process basin (1) on or in the immediate vicinity of an end face (6), the openings, which are formed by the two ends of the tubular structure (3) are limited, point in the direction of the opposite end face (6). Device according to Claim 4, characterized by two tubular structures (3) which are arranged within the process basin (1) on or in close proximity to an end face (6), the tubular structures (3) on or in close proximity to the same end face (6) or on or in the immediate vicinity of opposite end faces (6) are arranged, in each of the tubular structures (3) a bidirectional pump (2) is arranged and wherein the openings, which are delimited by the two ends of each tubular structure (3), each point in the direction of the opposite end face (6). Device according to one of the preceding claims, characterized in that the at least one tubular structure (3) with the bidirectional pump (2) arranged in it is arranged in or on the process basin (1) on one end face (6), with the opposite The end face (6) of the process basin (1) is provided with at least two spaced apart unidirectional pumps (4). Device according to one of the preceding claims, characterized in that it comprises one or more of the following elements: - A shut-off device (7) for the pump (2); - At least one solid-state filter (8) which is arranged inside the tubular structure (3) or at the ends thereof; - an overflow channel. Device according to one of the preceding claims, characterized in that the pump (2) which is arranged inside the at least one tubular structure (3) is an acid- and / or heat-resistant pump with a heat resistance of up to 65 ° C. Device according to one of the preceding claims, characterized in that the pump (2), which is arranged within the at least one tubular structure (3), has a variable delivery range between 10 and 180,000 L / h. Device according to one of the preceding claims, characterized in that the pump (2), which is arranged within the at least one tubular structure (3), has an output of <1 kW. Device according to one of the preceding claims, characterized in that the pump (2), which is arranged within the at least one tubular structure (3), has an electronic control. Device according to one of the preceding claims, characterized in that the pump (2) which is arranged within the at least one tubular structure (3) is selected from the group consisting of propeller pumps, centrifugal pumps, rotary lobe pumps, rotary lobe pumps, flap pumps, gear pumps, eccentric screw pumps , Peristaltic pumps and pneumatic diaphragm pumps. Method for surface treatment of objects, comprising the steps: - Provision of a device according to one of the preceding claims; - Arranging an object (9) within the process basin (1) filled with process liquid (10); - Let flow around and / or. Letting process liquid (10) flow through the object (9), the pump (2) conveying the process liquid (10) in one direction within the tubular structure (3). Method according to Claim 13, characterized in that the process liquid (10) flows around the object (9) for a period of time t and then the direction of rotation of the pump (2) is changed so that the process liquid (10) within the tubular structure (3 ) is conveyed in the opposite direction. Method according to one of the preceding claims, characterized in that the process liquid (10) surrounding the object (9) moves in a turbulent flow profile.

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