Temperature control system for the heat treatment of workpieces to be coated

Abstract

A temperature control system for the heat treatment of workpieces (W) to be coated comprises a system housing (6) that encloses an inlet area (E) for the entry of the workpieces (W), a heat treatment area (WB) for the application of an elevated heat treatment temperature (TW) to the workpieces (W), and an outlet area (A) for the exit of the workpieces (W), wherein the inlet area (E) has at least two inlet-side temperature control sections (E1, E2, E3) arranged one after the other and the outlet area (A) has at least two outlet-side temperature control sections (A1, A2, A3) arranged one after the other, a conveying system (8) by means of which the workpieces (W) can be moved successively along a transport path (P) in a transport direction (R) through the inlet area (E), the heat treatment area (WB) and the outlet area (A), and the transport path (P) runs from the inlet area (E) to the outlet area (A) in a substantially U-shape.wherein a first equalization zone (Z1) comprising a first inlet-side temperature control section (E1) and a first outlet-side temperature control section (A1) adjacent to it, and a second equalization zone (Z2) comprising a second inlet-side temperature control section (E1) and a second outlet-side temperature control section (A2) adjacent to it, are formed, as well as an airflow arrangement (L) by means of which a first heat exchange airflow (S1) can be generated in the first equalization zone (Z1) and a second heat exchange airflow (S2) can be generated in the second equalization zone (Z2). It is provided that the first heat exchange air flow (S1) and the second heat exchange air flow (S2) in the transport path (P) each form a boundary flow section (GS) which is oriented perpendicular to the transport direction (R), and wherein adjacent boundary flow sections (GS) of immediately neighboring compensation zones (Z1, Z2, Z3) are oriented in the same direction.

Description

[0001] The invention relates to a temperature control system for the heat treatment of workpieces to be coated according to the preamble of claim 1. Such a temperature control system can, for example, be formed by a recirculating air dryer of a coating system.

[0002] Temperature control systems are used primarily for drying workpieces, especially before or after coating, for curing powder coatings, for tempering, or for other technical purposes. In each case, the heat treatment either prepares the workpieces for coating or, after a coating process such as powder coating, it provides post-treatment. The temperature control system typically comprises a housing through which a conveyor belt for the workpieces extends. The workpieces are guided along a transport path through the housing by this conveyor belt.

[0003] The temperature control system according to the invention comprises a housing that encloses an inlet area for the workpieces, a heat treatment area for subjecting the workpieces to an elevated heat treatment temperature, and an outlet area for the workpieces' exit. The heat treatment area is located within the housing between the inlet and outlet areas. An elevated heat treatment temperature can be generated in the heat treatment area. This heat treatment temperature is preferably in a range between 100 °C and 300 °C.

[0004] The entrance area has at least two in-situ temperature control sections and the exit area has at least two in-situ temperature control sections.

[0005] The temperature control system further comprises a conveyor system by means of which the workpieces can be moved successively along a transport path in one direction through the inlet area, the heat treatment area, and the outlet area. The transport path runs from the inlet area to the outlet area in a generally U-shape. "Generally U-shaped" here refers to any configuration in which the transport path has two essentially parallel end sections connected by an intermediate section, which is preferably arc-shaped, but can alternatively have any other shape, such as W-shaped or meandering. Within the temperature control system, particularly within the system housing, a first equalization zone is formed, comprising a first inlet-side temperature control section and an adjacent first outlet-side temperature control section.Furthermore, a second equalization zone is formed, which includes a second inlet-side temperature control section and a second outlet-side temperature control section adjacent to this.

[0006] The temperature control system according to the invention further comprises an airflow arrangement by means of which a first heat exchange airflow can be generated in the first equalization zone and a second heat exchange airflow in the second equalization zone. Optionally, any number of further equalization zones can be provided.

[0007] To generate the desired heat treatment temperature, a heat source is preferably provided, which can be any heating device, such as a burner or a furnace. The heat source is configured so that a corresponding temperature, in particular the circulating air temperature, can be set, at least in certain areas, within the heat treatment section of the system housing. The workpieces are guided through the heat treatment area by means of a conveyor system, which is preferably a transport system for moving the workpieces.

[0008] To achieve the required temperatures in the heat treatment area, heat sources that use natural gas as an energy carrier are most commonly employed. Alternative energy carriers include petroleum or electricity. Particularly with natural gas-fired heat sources, energy costs have risen considerably in recent years, making the operation of existing temperature control systems expensive. Other energy carriers are often unable to provide the required temperatures continuously. Therefore, there is a need to further develop such temperature control systems to reduce their energy consumption.

[0009] From DE 199 41 184 A1, a paint drying system is known which comprises several paint drying modules connected in series. These modules have an inlet area in the form of an inlet lock and an outlet area in the form of an outlet lock. The known paint drying system also includes a clean gas pipeline in which heated exhaust air is carried as clean gas. The heated exhaust air is used to maintain the recirculated air, which is circulated in a recirculation system, at a desired temperature level. The hot recirculated air can be generated by an oven and is used in the heat treatment section for the heat treatment of the workpieces.

[0010] In this and other known temperature control systems, the inlet and outlet areas are primarily used to largely prevent hot air from escaping the system housing at the openings when workpieces enter or exit the system. This is mainly intended to prevent the surrounding area, such as a production hall, from overheating. However, heating the workpieces themselves still requires a significant amount of energy in these known temperature control systems, resulting in the aforementioned high energy costs.

[0011] US Patent 2011 / 0132572 A1 describes a heat treatment and drying system, particularly for metal workpieces coated with powder paint. In the known drying system, the workpieces are conveyed in a U-shape from an inlet area through a heat treatment area to an outlet area. Due to the U-shaped conveying path of the workpieces, the respective inlet and outlet areas are arranged parallel to each other and form temperature control sections. Within these temperature control sections, heat exchange occurs through air circulation to transfer the heat from the already dried workpieces to the cold workpieces entering the inlet area before they exit the drying system. This heat exchange takes place in stages in successive equalization zones, each comprising an inlet-side and an adjacent outlet-side temperature control section.A disadvantage of this drying system is that the airflows between the temperature control sections are diffuse, resulting in turbulence. This leads to crossflows between the equalization zones. Although partitions are provided between the equalization zones, these can only extend around the transport path of the metal workpieces. It has been shown that these heat exchange airflows crossing the equalization zones reduce the efficiency of heat exchange between the outlet-side and inlet-side temperature control sections.

[0012] Against this background, the object of the invention is to avoid the aforementioned disadvantages in a temperature control system of the generic type and, in particular, to reduce the energy consumption and increase the efficiency of the temperature control system.

[0013] This problem is solved by a temperature control system for the heat treatment of workpieces to be coated, comprising the features of claim 1. It is provided that the first heat exchange airflow and the second heat exchange airflow in the transport path each form a boundary flow section oriented perpendicular to the transport direction. Adjacent boundary flow sections of immediately adjacent equalization zones, or of the heat exchange airflows generated therein, are oriented in the same direction.

[0014] The basic concept of the invention is to utilize the two legs of the U-shaped transport path to create equalization zones within which a heat exchange airflow is generated. This heat exchange airflow absorbs heat from workpieces that are moving from the heat treatment area to the discharge area and which have been heated to an elevated temperature, typically between 50 and 350°C, but particularly between 100°C and 300°C, by the heat treatment. This process removes heat from the workpieces in the discharge area and directs it to the inlet area, where the relatively cooler workpieces enter. Conversely, the cooler air in the inlet area is directed to the discharge area, where the relatively warm workpieces from the heat treatment area are transported.In this way, the workpieces exiting the heat treatment area are cooled, and the workpieces in the incoming area are preheated before being moved into the heat treatment area. This reduces the loss of heat energy from the outgoing workpieces in the temperature control system and simultaneously uses the available heat energy to heat the workpieces entering the system, thereby reducing the heat energy required in the heat treatment area. Essentially, this achieves heat recovery similar to a heat exchanger, reducing the energy required to heat the workpieces to the heat treatment temperature.

[0015] It has been shown that the efficiency of heat recovery is significantly increased when cross-flows between adjacent equalization zones are reduced. A laminar airflow within an equalization zone increases the efficiency of heat recovery.

[0016] Since completely closed partitions between the individual exchange zones are not possible, as these would otherwise block the transport path for the workpieces, other measures are necessary to prevent cross-flow or turbulence between the first and second heat exchange air streams. This is advantageously achieved by ensuring that the flow directions of the boundary flow sections—that is, those sections of the heat exchange air streams located directly at the zone boundaries of the equalization zones—are the same. A boundary flow section is therefore defined as a portion of the heat exchange air stream that runs along a zone boundary. The zone boundary is the boundary region of the equalization zone that borders the immediately adjacent equalization zone.In other words, the first equalization zone and the second equalization zone are separated from each other by a zone boundary, with the boundary flow sections of the first heat exchange air flow and the second heat exchange air flow being in the same direction along this zone boundary.

[0017] Simultaneously, the boundary flow sections are designed perpendicular to the transport direction in order to achieve, on the one hand, a nearly laminar airflow and, on the other hand, a direct and therefore particularly efficient heat exchange. Diffuse turbulence of the air is thus avoided, resulting in targeted heat transfer.

[0018] In a preferred embodiment of the invention, the first heat exchange airflow in the first equalization zone and / or the second heat exchange airflow in the second equalization zone forms a recirculating airflow that includes at least one active flow section crossing the transport path. The formation of a recirculating airflow is energetically advantageous because it enables effective temperature exchange between the workpieces in the inlet and outlet areas, whereby the incoming workpieces are heated and the outgoing workpieces are cooled within the system housing. In particular, this reduces heat losses. For good heat exchange, it is advantageous if the recirculating airflow includes at least one active flow section that crosses the transport path. However, each recirculating airflow can also include several active flow sections. The active flow sections preferably run perpendicular to the transport direction of the workpieces.However, different sections of the effective flow within a common recirculated airflow can be oriented differently.

[0019] The recirculated airflow can have two active flow sections that run parallel to each other and in opposite directions. For the purposes of this application, active flow sections are defined as sections of the heat exchange airflow that are guided directly, and in particular without deflection, through the transport path. It is particularly preferred if the active flow sections are guided without deflection from the outlet-side temperature control section to the inlet-side temperature control section. However, it is also possible for the heat exchange airflow to be deflected between the outlet-side and inlet-side temperature control sections. Within the outlet-side or inlet-side temperature control section, however, an active flow section of the heat exchange airflow runs perpendicular to the transport direction of the workpieces through the transport path.Therefore, it is also possible that within a compensation zone two effective flow sections are formed that are parallel to each other and in the same direction.

[0020] In general, it is preferred that each active flow section has at least one boundary flow section. The active flow sections, which are segments of the respective heat exchange air flow guided by the transport path, form the boundary flow sections at zone boundaries between two equalization zones. The boundary flow sections of adjacent equalization zones are oriented in the same direction, i.e., they have the same flow direction, in order to prevent crossflows.

[0021] The invention may also provide that the recirculated airflow has a return flow section that runs outside the transport path, in particular parallel to the active flow section. The heat exchange airflow can be returned from the outlet-side temperature control area to the inlet-side temperature control area or vice versa via the return flow section. The return flow section can thus be used to generate a recirculated airflow, while the active flow sections, which extend transversely to the transport path, are, for example, uniformly directed.

[0022] In a further embodiment of the temperature control system according to the invention, a recirculating air flow can be formed in each equalization zone, wherein the recirculating air flows of immediately adjacent equalization zones each have opposing flow directions. This does not preclude the possibility that the recirculating air flows of immediately adjacent equalization zones have boundary flow sections that are oriented in the same direction. For this embodiment as well, the effective flow sections run perpendicularly through the transport path and each has boundary flow sections, wherein the boundary flow sections of adjacent equalization zones are oriented in the same direction. The flow directions of the recirculating air flows can differ, in particular, by the fact that the recirculating air flows circulate, for example, in different directions of rotation.Air currents with opposite directions of rotation, for example an air current that rotates clockwise and an air current that rotates counterclockwise, are referred to as air currents with opposing directions of flow.

[0023] Particularly efficient heat transfer from outlet-side to inlet-side temperature control sections is achieved when the respective active flow section runs directly, and especially without deflection, from the inlet-side temperature control section to the outlet-side temperature control section of the respective equalization zone, or vice versa. In this configuration, the active flow section preferably runs horizontally between the temperature control sections to ensure effective cooling of the workpieces coming from the heat treatment area before they exit the system housing, and effective preheating of the workpieces transported to the heat treatment area after they enter the system housing. The active flow section is oriented perpendicular to the transport direction of the workpieces.

[0024] In an alternative version of the temperature control system, the heat exchange air flows of the individual compensation zones can each have two active flow sections, wherein an outlet-side active flow section runs through the outlet-side temperature control section and an inlet-side active flow section runs through the inlet-side temperature control section of the respective compensation zones, and wherein the outlet-side active flow section and the inlet-side active flow section run parallel to each other. The outlet-side active flow section and the inlet-side active flow section can be oriented in the same direction.

[0025] In the temperature control system according to the invention, the airflow arrangement can have at least one first discharge device in the first equalization zone for generating the first heat exchange airflow and a second discharge device in the second equalization zone for generating the second heat exchange airflow. The first discharge device and the second discharge device can be controlled independently. In this way, different first and second heat exchange airflows can be set. In particular, the mass flow rate of the heat exchange airflows can be set differently to achieve different heat exchange characteristics in the respective equalization zones. In this way, the energy efficiency of the temperature control system can be further improved.

[0026] The exhaust systems can each include at least one blowing fan and / or one suction fan. A qualified professional will select the appropriate fan type based on the specific structural conditions of the temperature control system.

[0027] In a preferred embodiment of the temperature control system according to the invention, air guides are arranged in the first equalization zone and / or the second equalization zone, particularly outside the transport path, to form the recirculated airflow. The air guides enable a targeted alignment of the recirculated airflow, in particular of the effective flow sections of the heat exchange airflows, thereby further preventing diffuse flows, especially turbulence or cross-flows between the individual equalization zones.

[0028] In particular, the active flow section of the recirculated airflow can be linear between an inlet-side discharge device and / or inlet-side air guides and an outlet-side discharge device and / or outlet-side air guides. At least the air guides, and preferably also the discharge devices, are preferably located close to the transport path so that an as undisturbed as possible laminar active flow section can be generated. The at least nearly laminar flow preferably generated in the active flow section results in particularly good heat transfer from the heated workpieces in the outlet-side cooling section to the cold workpieces in the inlet-side cooling section.

[0029] The air guides can be at least partially integrated into the base, side wall, and / or ceiling of the system housing. Such integration allows for a more compact design of the system housing. Furthermore, the air guides can be adapted to the shape of the system housing, which is advantageous for optimizing the heat exchange airflow.

[0030] In general, the compensation zones can be partially separated from each other by partitions located outside the transport path and extending perpendicular to it. These partitions can also simultaneously act as air guides, particularly to direct the boundary flow sections perpendicularly through the transport path.

[0031] Furthermore, the temperature control system can include at least one third equalization zone with a third inlet-side temperature control section and a third outlet-side temperature control section adjacent to it. In this configuration, the workpieces are thus guided into the heat treatment area through at least three inlet-side temperature control sections and exit the heat treatment area through three outlet-side temperature control sections. In this respect, three equalization zones are formed, each comprising an outlet-side temperature control section and an inlet-side temperature control section. Heat exchange takes place in each of the equalization zones between the workpieces guided on the outlet side and the workpieces guided on the inlet side. The three equalization zones can be separated from each other by partitions. The partitions are preferably positioned at the zone boundaries.

[0032] Along the zone boundaries, each individual heat exchange airflow of the respective equalization zone has a boundary flow section. The boundary flow section of the first equalization zone bordering the second equalization zone and the boundary flow section of the second equalization zone bordering the first equalization zone—that is, the boundary flow sections running along the zone boundary between the first and second equalization zones—are preferably oriented in the same direction. The same applies analogously to the two boundary flow sections of the second and third equalization zones that border the zone boundary between the second and third equalization zones. These two boundary flow sections are also preferably oriented in the same direction.The boundary currents at the zone boundary between the first and second equalization zones, and the boundary currents at the zone boundary between the second and third equalization zones, can, however, have different directions. It is also possible, though, that all boundary current segments of the three equalization zones have the same flow direction.

[0033] It should be noted that all the features of the object according to the invention described above are interchangeable or combinable with each other, provided that such an exchange or combination is not excluded for technical reasons.

[0034] The figures illustrate exemplary embodiments of the invention. They show: Fig. 1 a schematic representation of the temperature control system according to the invention in longitudinal section, in which three equalization zones with heat exchange air flows in the same direction are provided; Fig. 2 a cross-sectional view through the temperature control system according to Fig. 1 along the intersection line II-II; Fig. 3 a cross-sectional view of a temperature control system according to the invention in a further preferred embodiment with an outlet-side blowing fan as a blowing device; Fig. 4 a schematic sectional view of a temperature control system according to the invention in a further preferred embodiment with an inlet-side blowing fan as a blowing device; Fig. 5 a cross-sectional view of a temperature control system according to the invention in a further preferred embodiment, wherein the heat exchange airflow has two working flow sections running parallel and vertically from bottom to top; Fig. 6 a cross-sectional view of a temperature control system according to the invention in a further preferred embodiment, wherein the heat exchange airflow has two parallel effective flow sections running from top to bottom; and Fig. 7 a schematic representation of a further embodiment of a temperature control system according to the invention in a partial longitudinal section view, wherein horizontally running recirculating air flows are formed within the individual compensation zones.

[0035] Fig. Figure 1 schematically shows a temperature control system 2, which is arranged by way of example in a hall 4 and has a system housing 6 that has an inlet area E for the entry of workpieces W and an outlet area A for the exit of the workpieces W. Between the inlet area E and the outlet area A is a heat treatment area WB in which the workpieces W are subjected to an elevated heat treatment temperature TW.

[0036] A conveyor system 8 extends through the plant housing 6, transporting the workpieces W from the input area E via the heat treatment area B to the output area A. The transport direction R of the conveyor system 8 is in Fig. 1. This is represented by arrows labeled "R". The transport direction R leads from the inlet area E, through the heat treatment area WB, to the outlet area A.

[0037] Within the plant housing 6, a transport path P is also provided, along which the workpieces W are transported through the plant housing 6 by means of the conveyor system 8. The transport path P, with the exception of the conveyor system 8 carrying the workpieces W, is free of obstructions. In particular, the transport path P is designed such that the workpieces W can be guided unhindered through the plant housing 6 by means of the conveyor system 8. As shown in Fig. As can be clearly seen, the transport path P essentially runs in a U-shape from the entrance area E to the exit area A.

[0038] The inlet area E has several inlet-side temperature control sections E1, E2, E3 arranged one after the other in the transport direction R. The outlet area A also has several outlet-side temperature control sections A1, A2, A3 arranged one after the other in the transport direction R. The first inlet-side and outlet-side temperature control sections E1, A1 are located in a first equalization zone Z1. Furthermore, a second equalization zone Z2 is provided, in which the second inlet-side temperature control section E2 and the second outlet-side temperature control section A2 are located. In the embodiment shown here, a third equalization zone Z3 is also provided, which comprises the third inlet-side temperature control section E3 and the third outlet-side temperature control section A3.

[0039] The compensation zones Z1, Z2, and Z3 are arranged adjacent to one another. The individual compensation zones Z1, Z2, and Z3 are separated from each other by zone boundaries ZG. In the illustrated embodiment, the zone boundaries ZG are defined according to... Fig. 1 defined by partition walls 12 which extend outside the transport path P in the plant housing 6.

[0040] Within the equalization zones Z1, Z2, and Z3, heat exchange airflows S1, S2, and S3 are formed. Corresponding airflow arrangements L are provided for this purpose. Specifically, each equalization zone Z1, Z2, and Z3 has an airflow arrangement L, where the airflow arrangements L are formed by discharge devices L1, L2, and L3. Thus, a first discharge device L1 is located in the first equalization zone Z1, a second discharge device L2 in a second equalization zone Z2, and a third discharge arrangement L3 in a third equalization zone Z3. The discharge devices L1, L2, and L3 each generate the corresponding heat exchange airflow S1, S2, and S3.

[0041] As in Fig. As can be seen in Figure 1, the heat exchange air flows S1, S2, S3 in the respective compensation zones Z1, Z2, Z3 are each aligned along transport path P perpendicular to the transport direction R. Each heat exchange air flow S1, S2, S3 has an effective flow section WS that extends across transport path P in the inlet area E and from there to transport path P in the outlet area A, and then across the outlet area exactly perpendicular to the transport direction R. Alternatively, as shown in Figure 1, the heat exchange air flows S1, S2, S3 are also shown in Figure 1. Fig. 1. The heat exchange air flows S1, S2, S3 or their respective effective flow sections WS can also be directed from the outlet area to the inlet area.

[0042] In any case, within the scope of this application, the term "effective flow section WS" refers to a portion of the heat exchange air flow S1, S2, S3 that, while maintaining its direction, passes through the transport path P. If the heat exchange air flow S1, S2, S3 maintains its direction and again encounters or passes through the transport path P, this flow section is formed by the same effective flow section WS.

[0043] In the embodiment according to Fig. Thus, the first heat exchange airflow S1 has an effective flow section WS that runs from the transport path P in the first inlet-side temperature control section A1 to the transport path P in the first outlet-side temperature control section E1. Similar heat exchange airflows S2 and S3 are formed in the two further equalization zones Z2 and Z3, each of which has an effective flow section WS that runs from the respective inlet-side temperature control section to the outlet-side temperature control section.

[0044] In the embodiment according to Fig. 1. The airflow arrangements L are each formed by blowing fans arranged in the inlet area E, which are operated with a direction of rotation in which air is drawn in from the rear, or drive side, and blown out to the front, or rotor side. Alternatively, suction fans can also be used, which are operated with a direction of rotation in which air is drawn in from the front and blown out to the rear, in order to generate an opposite direction to the depicted heat exchange airflow S1, S2, S3 or their effective flow sections WS. It is also possible that additional airflow arrangements L are provided in the outlet area A. Such airflow arrangements L are shown in Fig. 1 is shown as an example by dashed lines. Further airflow devices may also be provided in the heat treatment area WB.

[0045] Fig. Figure 2 shows the temperature control system 2 according to Fig. Figure 1 shows a cross-sectional view along line AA in the direction of the heat treatment area WB. Specifically, the section runs through the second equalization zone Z2. This cross-sectional view shows that, in the illustrated embodiment, the workpieces W are conveyed by the conveyor system 8 essentially suspended along the transport path P. Due to its U-shape, the transport path P passes through both the second inlet-side temperature control section E2 and the second outlet-side temperature control section A2. The two temperature control sections E2 and A2 are located in the second equalization zone Z2. The second heat exchange airflow S2 is formed in the second equalization zone Z2. The second heat exchange airflow S2 is designed as a recirculated airflow that is circulated within the system housing 6, specifically within the second exchange zone Z2.

[0046] The recirculated airflow has an active flow section WS, which is generated by the second discharge device L2 in a substantially straight or laminar flow from the second inlet-side temperature control section E2 to the second outlet-side temperature control section A2. In the outlet area A, the second heat exchange airflow S2 encounters air guides 10. These guides direct the recirculated airflow in such a way that a return flow section RS forms along the system housing 6. As shown, the return flow section RS can be routed along the bottom and / or the top of the system housing 6. In any case, the return flow section RS runs in the opposite direction to the active flow section WS and perpendicular to the transport path P.The recirculated air flow thus flows from the second discharge device L2 via the effective flow section WS to the second outlet-side temperature control section A2 and from there by means of the air guides 10 back to the second inlet-side temperature control section E2 and the second discharge device 12.

[0047] In this way, a heat exchange between the workpieces W in the second inlet-side temperature control section E2 and in the second outlet-side temperature control section A2 is achieved by means of the second heat exchange air flow S2, whereby the workpieces W transported in the inlet area E are heated on the way to the heat treatment area WB and at the same time the workpieces W transported in the outlet area A are cooled before exiting into hall 4.

[0048] Fig. Figure 2 also shows, in the background, the partition wall 12, which partially separates the second compensation zone Z2 from the third compensation zone Z1. As explained, the partition wall 12 thus defines a zone boundary ZG, which in Fig. 1 is represented by a dashed line.

[0049] Fig. 1 and Fig. Figure 2, taken together, shows that boundary flow sections GS of the respective heat exchange air flows S1, S2, and S3 run along the zone boundaries ZG. The sections or areas of the effective flow sections WS located directly along the zone boundary ZG are referred to as boundary flow sections GS within the scope of this application. The boundary flow sections GS of immediately adjacent equalization zones Z1 and Z2, as well as Z2 and Z3, are oriented in the same direction, i.e., they have the same flow direction. This is demonstrated in the embodiment according to... Fig. 1. This is achieved simply by ensuring that the effective flow sections WS of the first, second, and third heat exchange air flows S1, S2, S3 each have the same flow direction. In particular, the effective flow sections WS in all equalization zones Z1, Z2, Z3 run uniformly from the inlet area E to the outlet area A or vice versa.

[0050] Alternatively, each compensation zone Z1, Z2, Z3 may have more than one active flow section WS. In particular, active flow sections WS can be configured with different flow directions. It is essential, however, that the boundary flow sections GS, i.e., those parts of the active flow sections WS that run along the zone boundaries ZG and share a zone boundary ZG, have the same direction. For an example, reference is made to the embodiment shown in [reference to figure]. Fig. Reference is made to Figure 7, in which the recirculated airflow in the individual compensation zones Z1, Z2, Z3 each has two active flow sections WS that are oriented in opposite directions. However, the boundary flow sections GS, i.e., the parts of the active flow sections WS that are arranged at a common zone boundary ZG, are oriented in the same direction. The embodiment according to Fig. Point 7 will be discussed in more detail later.

[0051] The temperature control system 2 according to the invention operates as follows: In the case of the temperature control system 2 according to Fig. 1. The workpieces W are introduced into the system housing 6 via the conveyor system 8 in the transport direction R through the inlet area E. The workpieces W first pass through the inlet-side temperature control section E1. Upon entering the inlet area E, the workpieces W typically have a temperature that essentially corresponds to the ambient temperature of the temperature control system 2. If the temperature control system 2 is located in a hall 4, as shown, the workpieces will, for example, have a hall temperature TH when entering the system housing 6.

[0052] In the first inlet-side temperature control section E1, the workpieces W entering and being transported towards the heat treatment area WB are heated to an initial workpiece temperature T1 by the first heat exchange airflow S1, which is guided as a recirculating airflow and carries heat from the first outlet-side temperature control section A1. Simultaneously, the heat exchange airflow S1 extracts heat from the workpieces W coming from the heat treatment area WB in the first outlet-side temperature control section A1 before they exit the housing 6, thereby cooling them to a temperature T6.

[0053] From the first inlet temperature control zone E1, the workpieces W enter the second inlet temperature control zone E2. In this zone, the workpieces W are heated to a second temperature T2 by the second heat exchange airflow S2, which carries heat from the second outlet temperature control zone A2. Simultaneously, the heat exchange airflow S2 extracts heat from the workpieces W coming from the heat treatment zone WB in the second outlet temperature control zone A2, cooling them to a temperature T5. The workpieces W then travel through the conveyor system 8 in the transport direction R to the third inlet temperature control zone E3. The third heat exchange airflow S3, flowing in the third exchange zone Z3, heats the workpieces W in the third inlet temperature control zone E3 to a third temperature T3.At the same time, the heat exchange airflow S3 extracts heat from the workpieces W coming from the heat treatment area WB in the third outlet-side temperature control section A3 and thereby cools them down to a temperature T4.

[0054] The workpieces W, transported from the inlet area E to the heating area WB, are preheated in three steps and then enter the heat treatment area WB, where they are subjected to the heat treatment temperature TW, which is preferably between 100°C and 300°C, particularly between 150°C and 250°C, and preferably between 170°C and 230°C. Simultaneously, the workpieces W, transported from the heating area WB to the outlet area A, are cooled in three steps before exiting the housing 6, particularly into hall 4.

[0055] Fig. Figure 3 shows an alternative embodiment in which a second heat exchange airflow S2 is also formed in the second equalization zone Z2, the effective flow section WS of which also runs from the second inlet-side temperature control area A2 to the second outlet-side temperature control area E2. The conveying device 8 transports the workpieces W along the transport path P in a suspended manner. Here, too, the effective flow section WS is oriented perpendicular to the transport direction R of the workpieces W. Furthermore, the second heat exchange airflow S2 is also designed as a recirculating airflow, which has an inlet section ZS that is guided outside the transport path P along the system housing 6.

[0056] The embodiment differs essentially according to Fig. 3 of the embodiment according to Fig. 1. The difference lies in the fact that the second discharge device L2 has a different configuration and positioning. Specifically, the second discharge device L2 is located near the floor in the outlet area A, particularly in the second outlet-side temperature control area A2. The discharge device L2 conveys the air via the inlet section ZS along the bottom of the system housing 6 to the second inlet-side temperature control area E2. Air guides 10 are provided on the side wall of the system housing 6 at this point. These guides receive the second heat exchange airflow S2 from the inlet section ZS, redirect it, and direct it perpendicular to the transport direction R as the effective flow section WS through the second equalization zone Z2. To direct the recirculated airflow from the transport path P in the second outlet-side temperature control area A2 to the second discharge device L2, air guides 10 are also provided on the side wall of the system housing 6.The air guides 10 are designed such that the second heat exchange airflow S2, after passing through the second outlet-side temperature control area A2, is deflected back downwards to the second discharge device L2 via the air guides 10.

[0057] In the corners of the system housing 6, particularly at the transitions between side walls and ceiling or between side walls and floor, additional air guides 10 are preferably arranged wherever no discharge devices L1, L2, L3 are provided, to prevent air turbulence in the corners. This preferably applies to all embodiments.

[0058] In Fig. Figure 4 shows a further embodiment of the temperature control system 2, which is essentially similar to the embodiment according to Figure 4. Fig. 3 is constructed. The only difference is that instead of a second exhaust device L2 on the outlet side, a second exhaust device L2 is provided on the inlet side. The second exhaust device L2 according to Fig. 4 is therefore located in the second inlet-side temperature control zone A2. The second discharge device L2 can again be designed as a blower fan, the discharge direction of which is vertically upwards. The second heat exchange airflow S2, drawn in via the return flow section RS, is consequently blown vertically upwards along a side wall in the outlet zone A2 of the system housing 6. The air guides 10 are located in the area of ​​the inlet-side side wall of the system housing 6, which deflect the second heat exchange airflow S2 and guide it horizontally through the second equalization zone Z2, perpendicular to the transport direction R.In the outlet area A, in particular in the second outlet-side temperature control section A2, further air guides 10 are provided outside the transport path P, which receive the second heat exchange airflow S2 from the active flow section WS, redirect it downwards and feed it back to the second discharge device L2 via the return flow section RS.

[0059] In Fig. Figure 5 shows an embodiment of a temperature control system 2 in which the second heat exchange airflow S2 has a different flow direction. Generally, the heat exchange airflows S1, S2, and S3 are each oriented perpendicular to the transport direction R. As an alternative to the horizontal orientation shown in the embodiments, the following can be used: Fig. 1 to 4 also a vertical orientation according to the Fig. 5 and Fig. 6, be provided. This is also the case in the embodiment according to Fig. Figure 5 shows a section through a temperature control system 2, which, by way of example, passes through the second equalization zone Z2. The cross-section shows the second inlet-side temperature control section E2 and the second outlet-side temperature control section A2. The transport path P, through which the conveyor system F transports the workpieces W, runs through the second inlet-side temperature control section E2 and the second outlet-side temperature control section A2. The individual equalization zones Z1, Z2, Z3 are arranged according to the embodiment shown. Fig. 1 separated from each other by partition walls 12, which also define the zone boundaries ZG.

[0060] In the embodiment according to Fig. A second discharge device L2, a blower fan, is provided in the system housing 6, located near the bottom in the inlet area E. The discharge device L2 generates a second heat exchange airflow S2, which is deflected vertically upwards into the transport path P via air guides 10, which are also located near the bottom. This creates two active flow sections WS. An inlet-side active flow section WSE runs through the transport path P in the second inlet-side temperature control section E2. An outlet-side active flow section WSA runs through the transport path P in the second outlet-side temperature control section A2. The outlet-side temperature control section WSA and the inlet-side temperature control section WSE are aligned parallel to each other and have the same flow direction. Specifically, the two active flow sections WSA and WSE run vertically from bottom to top through the system housing 6.In the area of ​​a ceiling of the system housing 6, further air guides 10 are arranged, which deflect the second heat exchange airflow S2 and lead via a return flow section RS, which runs along the side wall of the system housing 6 in the entrance area E, to the second discharge device L2.

[0061] It is understood that, for the purposes of the present invention, vertically extending active flow sections WS, such as the outlet-side active flow section WSA and the inlet-side active flow section WSE in the embodiment according to Fig. 5, each having boundary flow sections GS that run along the zone boundaries ZG. The boundary flow sections GS of immediately adjacent equalization zones Z1, Z2, Z3 have the same vertical flow direction. For the embodiment according to Fig. 5 therefore applies that the first compensation zone Z1, as well as the third compensation zone Z3 if applicable, also has an outlet-side active flow section WSA and an inlet-side active flow section WSE, whose limit flow sections each run from bottom to top and perpendicular to the transport direction R through the plant housing 6.

[0062] In Fig. Figure 6 shows a similar embodiment, which differs from the embodiment according to Fig. 5 differs in that the flow direction of the outlet-side active flow section WSA and the inlet-side active flow section WSE does not run from bottom to top, but from top to bottom through the system housing 6. For this purpose, the second discharge device L2 is arranged on the outlet side in the ceiling area of ​​the system housing 6, in particular in an inlet-side side wall. The second discharge device L2 generates a discharge flow that runs essentially horizontally from the inlet area A to the outlet area E. Air guides 10 arranged in the ceiling area redirect the second heat exchange air flow S2 so that it runs vertically from top to bottom through the second equalization zone Z2. Thus, an outlet-side active flow section WSA and an inlet-side active flow section WSE are formed in the transport path P.In the area of ​​the base of the system housing 6, further air guides 10 are arranged, which deflect the second heat exchange airflow S2 and feed it back to the second discharge device L2 via an outlet-side return flow section RS.

[0063] Even in the embodiment according to Fig. 6 The boundary flow sections GS of immediately adjacent compensation zones Z1, Z2, Z3 exhibit the same vertical flow direction. Therefore, it also applies here that the first compensation zone Z1, as well as the third compensation zone Z3 if applicable, also has an outlet-side effective flow section WSA and an inlet-side effective flow section WSE, whose boundary flow sections each run from top to bottom and perpendicular to the transport direction R through the plant housing 6.

[0064] In Fig. Figure 7 shows a further alternative embodiment of the temperature control system 2 according to the present invention in a longitudinal sectional view, in which the respective heat exchange air flows S1, S2, S3 in the individual equalization zones Z1, Z2, Z3 have opposing effective flow sections WS. Specifically, it is provided that a first heat exchange air flow S1 is formed in a first equalization zone Z1. The first heat exchange air flow S1 is designed as a recirculating air flow, which has two opposing effective flow sections WS. The two effective flow sections WS of the first equalization zone Z1 are fluidically coupled via a return flow section RS, which is formed outside the transport path P. The return flow section RS is formed, in particular, in the first outlet-side temperature control area A1.The backflow through the backflow section RS is effected by air guide medium 10, which achieves a corresponding deflection of the first heat exchange airflow S1.

[0065] In the first inlet-side temperature control section E1, an air guide 10 is also arranged, which deflects the first heat exchange airflow S1 outside the transport path P and feeds it to the first discharge device L1. The first discharge device L1 is arranged on a partition 12, which defines a zone boundary ZG. The zone boundary ZG separates the first equalization zone Z1 from the second equalization zone Z2.

[0066] The first discharge device L1 generates a first heat exchange airflow S1, which forms a boundary flow section GS along the zone boundary ZG. The boundary flow section GS is part of an active flow section WS, which runs from the first inlet-side temperature control area E1 to the first outlet-side temperature control area A1. The active flow section WS, which forms the boundary flow section GS, transitions into the return flow section RS, which, by means of the outlet-side air guide 10, deflects the first heat exchange airflow S1 and directs it back into the transport path P. There, another active flow section WS is formed, which runs horizontally through the first equalization zone Z1, perpendicular to the transport direction R. In this active flow section WS, the heat exchange airflow S1 flows from the first outlet-side temperature control area A1 to the first inlet-side temperature control area E1.Essentially, in the first compensation zone Z1, a recirculating airflow is formed that circulates clockwise.

[0067] The boundary flow section GS of the first heat exchange airflow S1 thus runs from the inlet area E to the outlet area A. In the second equalization zone Z2, a second heat exchange airflow S2 is formed, which essentially follows a similar path to the first heat exchange airflow S1. However, the path of the second heat exchange airflow S2 is a mirror image. In particular, the second heat exchange airflow S2, which is designed as a recirculating airflow, has a counterclockwise orientation. To achieve this, the second discharge device L2 is arranged next to the same partition 12 as the first discharge device L1. The second heat exchange airflow S2 generated by the second discharge device L2 initially forms an active flow section WS with a boundary flow section GS along the zone boundary ZG, which runs from the second inlet-side temperature control area E1 to the second outlet-side temperature control area A2.The second heat exchange airflow S2 is deflected in the second outlet-side temperature control section A2 via a return flow section RS and then flows along the next zone boundary ZG as a further boundary flow section GS from the second outlet-side temperature control section A2 to the second inlet-side temperature control section E2.

[0068] The third equalization zone Z3 is essentially identical to the first equalization zone Z1. In particular, a third heat exchange airflow S3 is formed in the third equalization zone Z3, which is oriented clockwise as a recirculating airflow. It forms an active flow section WS with a boundary flow section GS, which runs along the zone boundary ZG with the second equalization zone Z2. The boundary flow section GS of the third heat exchange airflow S3, located at the zone boundary ZG with the second equalization zone Z2, has the same flow direction as the boundary flow section GS of the second heat exchange airflow S2, which is located at the same zone boundary ZG.

[0069] In Fig. Figure 7 also indicates the heat treatment area, which is separated from the third compensation zone Z3 by a further partition wall 12.

[0070] It should be noted that all elements and features of the various embodiments of the temperature control system 2 described above are interchangeable or combinable with each other, provided that such an exchange or combination is not excluded for technical reasons.

Claims

[1] Tempering system for the heat treatment of workpieces to be coated (W) with a system housing (6) which encloses an inlet area (E) for the entry of the workpieces (W), a heat treatment area (WB) for subjecting the workpieces (W) to an elevated heat treatment temperature (TW), and an outlet area (A) for the exit of the workpieces (W), wherein the inlet area (E) has at least two tempering sections (E1, E2, E3) arranged one behind the other on the inlet side and the outlet area (A) has at least two tempering sections (A1, A2, A3) arranged one behind the other on the outlet side, with a conveyor system (8) by means of which the workpieces (W) can be displaced along a transport path (P) in a transport direction (R) one after the other through the input area (E), the heat treatment area (WB) and the output area (A), and the transport path (P) runs essentially U-shaped from the input area (E) to the output area (A), wherein a first compensation zone (Z1) comprising a first input-side tempering section (E1) and a first output-side tempering section (A1) adjacent thereto, and a second compensation zone (Z2) comprising a second input-side tempering section (E1) and a second output-side tempering section (A2) adjacent thereto are formed, and with an air flow arrangement (L) by means of which a first heat exchange air flow (S1) can be generated in the first compensation zone (Z1) and a second heat exchange air flow (S2) can be generated in the second compensation zone (Z2), characterized by that the first heat exchange air flow (S1) and the second heat exchange air flow (S2) in the transport path (P) each form a boundary flow section (GS) which is oriented perpendicular to the transport direction (R), and wherein adjacent boundary flow sections (GS) of immediately adjacent compensation zones (Z1, Z2, Z3) are aligned in the same direction. [2] Temperature control system according to claim 1, characterized by that the first heat exchange air flow (S1) in the first compensation zone (Z1) and / or the second heat exchange air flow (S2) in the second compensation zone (Z2) forms a recirculating air flow which has at least one effective flow section (WS) crossing the transport path (P). [3] Temperature control system according to claim 2, characterized by that the recirculating air flow has two effective flow sections (WS) which run parallel and opposite to each other. [4] Temperature control system according to claim 2 or 3, characterized bythat the effective flow sections (WS) each have at least one of the boundary flow sections (GS). [5] Temperature control system according to one of claims 2 to 4, characterized by that the recirculating air flow has a return flow section (RS) which runs outside the transport path (P), in particular parallel to the effective flow section (WS). [6] Temperature control system according to one of claims 2 to 5, characterized by that a recirculating air flow is formed in each compensation zone (Z1, Z2, Z3), wherein the recirculating air flows of immediately adjacent compensation zones (Z1, Z2, Z3) each have opposing flow directions. [7] Temperature control system according to one of claims 2 to 6, characterized bythat the effective flow section (WS) runs directly, in particular without deflection, from the inlet-side tempering section (A1, A2, A3) to the outlet-side tempering section (E1, E2, E3) of the respective compensation zone (Z1, Z2, Z3) or vice versa. [8] Temperature control system according to one of claims 2 to 6, characterized by that the heat exchange air flows (S1, S2) have two effective flow sections (WS), wherein an output-side effective flow section (WSA) runs through the output-side tempering section (A1, A2, A3) and an input-side effective flow section (WSE) runs through the input-side tempering section (E1, E2, E3) of the respective compensation zone (Z1, Z2, Z3), and wherein the output-side effective flow section (WSA) and the input-side effective flow section (WSE) run parallel to one another. [9] Temperature control system according to one of the preceding claims, characterized bythat the air flow arrangement (L) has at least one first blow-out device (L1) in the first compensation zone (Z1) for generating the first heat exchange air flow (S1) and a second blow-out device (L2) in the second compensation zone (Z2) for generating the second heat exchange air flow (S2). [10] Temperature control system according to claim 9, characterized by that the blow-out devices (L1, L2, L3) each have at least one blower fan and / or one suction fan. [11] Temperature control system according to claim 9 or 10, characterized by that in the first compensation zone (Z1) and / or the second compensation zone (Z2), in particular outside the transport path (P), air guiding means (10) for forming the recirculating air flow are arranged. [12] Temperature control system according to claim 11, characterized bythat the effective flow section (WS) of the recirculating air flow is formed between an inlet-side blow-out device (L1, L2, L3) and / or inlet-side air guiding means (10) and an outlet-side blow-out device (L1, L2, L3) and / or outlet-side air guiding means (10) or vice versa. [13] Temperature control system according to claim 11 or 12, characterized by that the air guiding means (10) are at least partially integrated into a floor, a side wall and / or a ceiling area of ​​the system housing (6). [14] Temperature control system according to one of the preceding claims, characterized by that the compensation zones (Z1, Z2, Z3) are separated from one another by partition walls (12) which extend outside the transport path (P) and perpendicular thereto. [15] Temperature control system according to one of the preceding claims, characterized bythat at least one third compensation zone (Z3) is provided with a third input-side tempering section (E3) and a third output-side tempering section (A3) adjacent to this.

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