METHOD FOR OPERATING A PLANT SYSTEM

Description

[0001] The invention relates to a method for operating a system for coating objects, in particular vehicle bodies, in which a) a coating system for coating objects is present at a company site; b) in the coating system, the objects are exposed to coating material in at least one coating booth through which an air stream is passed, which absorbs and removes any overspray of the coating material that arises; wherein c) the air stream is fed to a separation device of the coating system, which is operated with several filter modules in which a large part of at least the solids are separated from the overspray; d) each filter module is replaced with an empty filter module after a limit load with overspray is reached; e) a filter module is at least partially thermally regenerable.

[0002] During the manual or automatic application of paints to objects, a partial flow of the paint, which generally contains both solids and / or binders and solvents, is not applied to the object. This partial flow is referred to in the technical world as "overspray." In the following, the term overspray is always understood in the sense of a dispersed system, such as an emulsion or suspension, or a combination thereof. The overspray is captured by the air flow in the coating booth—in the case of painting, the paint booth—and fed into a separator so that the air can be returned to the coating booth after appropriate conditioning, if necessary.

[0003] DE 10 2019 105 256 A1 discloses the use of replaceable disposable filter modules, which, once a limiting overspray load is reached, are replaced with unloaded filter modules and thermally treated. The processing of such filter modules can be more energy-efficient and resource-efficient than the effort required for other separation concepts, such as commercially available wet scrubbers or electrostatic separation devices. However, such disposable filter modules are disposed of or recycled as a whole.

[0004] For filter modules that are at least partially thermally regenerable, it is possible to use the filter modules multiple times in circuits.

[0005] If a filter module is partially thermally regenerable, it comprises, on the one hand, a recyclable, reusable structure made up of one or more thermally regenerable, reusable components and, on the other hand, a disposable structure made up of one or more thermally decomposable, disposable components.

[0006] A thermally regenerable reusable component is a component that can withstand a thermal treatment in which existing overspray is thermally decomposed and thereby removed from the filter module at least once, and preferably repeatedly, without any loss of functionality. In contrast, a thermally decomposable disposable component is also decomposed during a thermal treatment in which existing overspray is thermally decomposed, so that after the thermal treatment, only the reusable structure of the filter module remains.

[0007] A suitable thermal treatment is preferably pyrolysis.

[0008] A filter module can also be completely thermally regenerated.

[0009] When a filter module is mentioned here in connection with the logistics according to the invention described below, this refers to an operational filter module which can be designed as a completely thermally regenerable filter module or as a filter module with a reusable structure and a disposable structure and can thus be used as a separation unit, or only to the thermally regenerable reusable structure which, in order to be operational, still needs to be supplemented with the components which were decomposed during the thermal treatment.

[0010] The filter module requirements of a coating system depend on the amount of overspray generated per unit of time, which in turn depends on the throughput of objects being coated in the system and / or the amount of coating material applied. The more objects being coated and / or the more coating material being applied, the more overspray is generated and the faster a filter module reaches its loading limit and must be replaced.

[0011] Nowadays, there is a demand for systems that can be flexibly adapted to changing production volumes or delivery processes, and generally to changing process flows, or that can respond flexibly to changing operating conditions. For a coating system at a company site, for example, this means that a change in the process flow will change the throughput of objects to be coated and / or the amount of applied coating material, which in turn affects the amount of overspray generated.

[0012] Changes in the process flow can therefore have a direct impact on the number of filter modules that must be available to operate the coating system or separation device.

[0013] Experience shows that most plants today operate at only partial load for 60% of their operating time. However, to accommodate peak throughput, the coating systems and their separation devices are designed for maximum throughput. This means that a correspondingly high number of filter modules are always kept in stock and stored at the operating site.

[0014] A ready-to-use filter module has a volume of between 1 m³ and 4 m³, in particular approximately 2 m³. The space required for storing a filter module or for the necessary components and parts is correspondingly high.

[0015] This leads, on the one hand, to high initial investment costs for filter modules, of which more are stored at the operating site than required for a large part of the plant's operating time, and, on the other hand, to special expenditure to accommodate these stored filter modules at the operating site.

[0016] It is now an object of the invention to provide a method of the type mentioned at the outset by which these disadvantages are at least reduced.

[0017] This task is solved in a method of the type mentioned above by f) the number of filter modules available at the operating location for operating the separation device defines an actual number; and g) the number of filter modules required at the operating location for operating the separation device defines a target number; and h) the difference between the actual number and the target number defines a requirement number if the actual number is less than the target number, or a surplus number if the actual number is greater than the target number; and i) a filter module pool is provided which comprises a stock number of filter modules, at least some of which are stored at a pool location that is different from the operating location of the coating plant;and j) a number of filter modules corresponding to the required number is physically transferred from the filter module pool to the operating site, whereby the actual number increases by the required number and the stock number decreases by the required number; or k) a number of filter modules corresponding to the surplus number is allocated to the filter module pool, whereby the actual number decreases by the surplus number and the stock number increases by the surplus number.

[0018] According to the invention, it is thus determined whether the number of filter modules available for the operation of the separation device, namely the actual number, corresponds to the number of filter modules required for the operation of the separation device, namely the target number.

[0019] The target number is not only the number of filter modules that are arranged in the separation device during operation. Rather, the target number also takes into account the number of unloaded, empty filter modules that must be kept on site, which are necessary for a smooth and delay-free exchange of loaded filter modules with unloaded ones.

[0020] Any need for additional filter modules required for the operation of the coating system in relation to the existing filter modules or a surplus of filter modules no longer required for the operation of the coating system is compensated for via the filter module pool.

[0021] To ensure that unexpected filter module failures, which could be caused, for example, by technical malfunctions in the separation device or defectively manufactured filter modules, can be quickly compensated for on-site, both the actual and target numbers can define a larger number of filter modules than is actually required for the operation of the coating system or its separation device for a given process. This ensures that a number of filter modules are always available at the operating site as a safety buffer.

[0022] If the process flow changes, the target number will either increase or decrease, whereas the actual number initially remains unchanged, as the number of filter modules available at the operating site remains unchanged. If additional filter modules are then brought to the operating site as needed, or excess filter modules are removed from the operating site, the actual number changes accordingly and subsequently matches the target number again.

[0023] The loading of the filter modules during the ongoing coating process can be determined intermittently or continuously. The limit loading of a filter module depends, among other things, on the design of the filter module and the materials used for it, as well as the overall operating sequence of the coating system and the coating booth. The amount of coating material already absorbed can be monitored using a measuring system. For example, a weighing device with weighing measuring cells can be provided for this purpose. Alternatively, the limit loading can be determined by means of differential pressure determination. The greater the load of a filter module, the greater the air resistance created by the filter module.

[0024] If the load determined in this way exceeds a predefined threshold, indicating that the filter module's load limit is about to be reached, automated steps can be initiated to reduce the actual number by one, resulting in a changed demand number at a time when the filter module's load limit has not yet been reached. In this way, the filter module quota at the operating site is proactively monitored and adjusted, ensuring continuous and trouble-free operation. The threshold to be applied can vary for different filter modules and depends on the volume and design of the filter module.

[0025] The contingent of filter modules in the filter module pool is stored at least in part at a location other than the operating site, so that no corresponding measures need to be taken for unused filter modules at the operating site of the coating system or the separation device.

[0026] Overall, the method according to the invention opens up the possibility of saving resources and investment costs, which will become even clearer below.

[0027] The procedure is particularly effective when a) the coating system is a first coating system with a first separation device and whose operating location is a first operating location; b) a second coating system with a second separation device is present at a second operating location which is different from the first operating location, wherein the second separation device is also operated with a plurality of filter modules, and wherein the filter modules of the first and second separation devices are at least compatible with one another; c) an actual number, a target number, a required number and a surplus number are determined separately for the first separation device and the second separation device.

[0028] Thus, filter modules for the first separation device and / or for the second separation device can be removed from the filter module pool or transferred from the first coating system and / or from the second coating system to the filter module pool or assigned to the filter module pool in order to respond to changes in the demand for filter modules at the operating locations.

[0029] The filter modules of the two coating systems or separation devices are preferably of identical design; however, as stated, it is generally sufficient if the filter modules are compatible with each other, so that all filter modules are suitable for both separation devices at the first and second operating locations.

[0030] If at least some of the filter modules in the filter module pool are stored at the first operating location and / or the second operating location, filter modules that are not required at one of the two operating locations can be transported directly to the other operating location if there is a higher demand there than for the existing filter modules. In this case, there is no need to first transport filter modules from the one operating location where there is a surplus to the pool location and then from there to the other operating location. If the operating location with the increased demand requires more filter modules than can be transferred from the other operating location, i.e. if the demand at one operating location is greater than the surplus at the other operating location, additional filter modules will be delivered from the pool location accordingly.

[0031] The process becomes more effective if a) a third coating system with a third separation device is present at a third operating location, or several further coating systems, each with a further separation device, are present at still further operating locations, each of which is different from the first and the second operating location, wherein the third or further separation devices are also operated with a plurality of filter modules and the filter modules of all separation devices are at least compatible with one another; b) an actual number, a target number, a required number and a surplus number are determined separately for the third or for each further separation device.

[0032] Filter modules for the existing separation devices can be taken from the filter module pool as needed or, if there is a surplus, can be transferred from the existing separation devices to the filter module pool in order to respond to changes in the demand for filter modules at the operating sites.

[0033] If a filter module quota can be delivered from a site where a surplus number has arisen, the spatial distance to various sites where there is a need for additional filter modules can also be determined and taken into account in order to keep transport routes as short as possible.

[0034] With regard to the compatibility of the filter modules, the above applies accordingly.

[0035] Preferably, at least some of the filter modules of the filter module pool are then stored at one, several or all operating locations, so that filter modules that are not required at one operating location can also be transported directly to another operating location if there is a higher demand there than for the existing filter modules.

[0036] Depending on the total number of coating systems with separation devices belonging to the system at various operating locations and the actual number applicable there, the system comprises a total system number of filter modules that is equal to the sum of the actual numbers of the individual existing separation devices and the inventory number of the filter module pool.

[0037] In extreme cases, the total system number corresponds to the number of filter modules required to operate all existing separation devices simultaneously at their respective maximum demand, including any surplus filter modules provided as a safety buffer at the operating site, and possibly plus a maintenance quota of filter modules to compensate for unusable filter modules undergoing maintenance or repair. This particularly applies to thermally regenerable filter modules.

[0038] However, the conveyor system described here is also based on the realization that such a large total number of filter modules will generally not be necessary to operate the plant system with multiple separation devices at different operating locations without resulting in filter module shortages at one or more operating locations. Consequently, the total number of filter modules in the system can be kept smaller than the sum of the filter modules that would have to be maintained with multiple separation devices at different operating locations. This can reduce the investment costs for each individual separation device at its respective operating location.

[0039] In the process described, the first coating plant or the first and the subsequent coating plants can be operated by one and the same operator, who also manages the filter module pool and the transport of the filter modules between the existing operating locations and the pool location.

[0040] The provision and coordination of the transport vehicle pool can, if necessary, be carried out by an independent or superior body which is independent of the operator of the coating plant or plants.

[0041] Different coating systems with separation devices can also be operated at different operating locations by two or more different operators, whereby all coating systems with their separation devices are nevertheless integrated into the system and linked to the filter module pool.

[0042] Filter modules can be transported between operating locations and / or the pool location as general cargo using established shipping concepts. Transport aids can be used for this purpose; for example, the filter modules can be loaded onto Euro pallets, if necessary in a transport crate, and transported using appropriately designed transport equipment. Truck transport by freight forwarders, for example, is also an option. Alternatively, special transport containers adapted to the filter modules can be used to house the filter modules.

[0043] The system preferably comprises a central control unit that receives or retrieves the actual and target quantities for a specific coating system or separation device at its operating location and uses this to calculate the required quantity or surplus quantity. Alternatively, a resulting required quantity or surplus quantity for a coating system can also be transmitted directly to the central control unit. The central control unit processes the data and, depending on the situation, initiates the transport of filter modules to a coating system and their collection from another coating system or the pool location, or the collection of filter modules from a coating system and their transport to the pool location.If necessary, the central control unit receives additional information from a coating plant that has a surplus of filter modules, indicating that the filter modules now assigned to the filter module pool can remain at the plant site. The control unit calculates the distribution of filter modules between the individual plant sites and the pool site using algorithms tailored to the plant system, taking into account the data from all plant sites and the filter module pool.

[0044] The data can be transmitted to the central control unit manually or automatically. In the latter case, the data should be transmitted automatically to the central control unit when a control device located at the operating site of a respective coating system or separation device registers a change in the actual or target number, which indicates a changed demand for filter modules.

[0045] With regard to the separation devices, the described method can be used particularly effectively if filter modules are used which are completely thermally regenerable.

[0046] The advantages are particularly evident when the filter modules of the filter module pool have a volume of 1 m 3< to 4 m 3< , especially 2 m 3<.

[0047] The filter modules assigned to the filter module pool can be housed in storage facilities, such as warehouses with or without shelving systems.

Claims

1. Method for operating a plant system for coating objects, in particular vehicle bodies, wherein a) a coating plant for coating objects is present at an operating site; b) in the coating plant a coating material is applied to the objects in at least one coating booth, through which an air flow is directed, which absorbs and removes arising overspray of the coating material; whereby c) the air flow is fed to a separating device of the coating plant, which is operated with a plurality of filter modules in which a majority of at least the solid materials is separated from the overspray; d) each filter module is replaced with an empty filter module after reaching a limit loading of overspray; e) a filter module is at least thermally partially regenerable; characterised in that f) the number of filter modules available at the operating site for the operation of the separating device defines an actual number; and g) the number of filter modules required at the operating site for the operation of the separating device defines a target number; and h) the difference between the actual number and the target number defines a demand number in case that the actual number is less than the target number, or defines a surplus number in case that the actual number is greater than the target number; and i) a filter module pool is provided comprising an inventory number of filter modules, at least a part of which is stored at a pool location that is different from the operating site of the coating plant; and j) a number of filter modules corresponding to the demand number is physically transferred from the filter module pool to the operating site, whereby the actual number is increased by the demand number and the inventory number is reduced by the demand number; or k) a number of filter modules corresponding to the surplus number is allocated to the filter module pool, whereby the actual number is reduced by the surplus number and the inventory number is increased by the surplus number.

2. Method according to claim 1, characterised in that a) the coating plant is a first coating plant with a first separating device and its operating site is a first operating site; b) a second coating plant with a second separating device is present at a second operating site which is different from the first operating site, wherein the second separating device is also operated with a plurality of filter modules, and wherein the filter modules of the first and second separating devices are at least compatible with one another; c) an actual number, a target number, a demand number and a surplus number are determined separately for the first separating device and the second separating device.

3. Method according to claim 2, characterised in that at least some of the filter modules of the filter module pool are stored at the first operating site and / or at the second operating site.

4. Method according to claim 3, characterised in that a) a third coating plant with a third separating device at a third operating site or a number of further coating plants, each with a respective further separating device, are present at further respective operating sites which are different in each case from the first and the second operating site, the third or the number of further separating devices also being operated with a plurality of filter modules and the filter modules of all the separating devices being at least compatible with one another; b) an actual number, a target number, a demand number and a surplus number are determined separately for the third or for each additional separating device.

5. Method according to claim 4, characterised in that at least some of the filter modules of the filter module pool are stored at one, several or all of the operating sites.

6. Method according to one of claims 1 to 5, characterised in that one or more filter modules are used which are completely thermally regenerable.

7. Method according to one of claims 1 to 6, characterised in that the filter modules of the filter module pool have a room volume of 1 m3 to 4 m3, in particular of about 2 m3.