Installation and method for coating objects

Abstract

An installation for coating objects, in particular vehicle wheels, has a dipping trough which is filled with a coating liquid into which the objects can be dipped. In order to reduce the complexity of the piping, there is provided a combined recirculation and filtration circuit for recirculating and filtering the coating liquid, wherein the recirculation and filtration circuit includes a pump, at least one recirculation outlet, arranged in the dipping trough, for the coating liquid, and a filtration device having a residue connection and a filtrate connection, wherein the residue connection is connected to the at least one recirculation outlet in the dipping trough.

What is claimed is: 
     
         1 . An installation for coating objects comprising:
 a) a dip tank which is filled with a coating fluid in which the objects can be dipped,   wherein   b) a combined circulation and filtration circuit is provided for circulating and filtering the coating fluid, wherein the circulation and filtration circuit comprises
 a pump having a pump inlet and a pump outlet, wherein the pump inlet is at least indirectly connected to the dip tank, 
 at least one circulation outlet which is arranged in the dip tank for the coating fluid, and 
 a filtration device whose inlet is connected to the pump outlet of the pump and which has a retentate connection and a filtrate connection, wherein the retentate connection is connected to the at least one circulation outlet in the dip tank. 
   
     
     
         2 . The installation according to  claim 1 , wherein there is provided an overflow tank into which the coating fluid from the dip tank can overflow, and in that the pump inlet of the pump is connected to the overflow tank. 
     
     
         3 . The installation according to  claim 2 , wherein the pump of the circulation and filtration circuit is constructed as a submersible pump and arranged in the overflow tank. 
     
     
         4 . The installation according to  claim 1 , wherein the retentate connection of the filter device and the at least one circulation outlet which is arranged in the dip tank are connected to each other without a buffer store being interposed. 
     
     
         5 . The installation according to  claim 1 , wherein the filtration device comprises an ultra-filtration module. 
     
     
         6 . The installation according to  claim 1 , wherein the circulation and filtration circuit comprises a temperature control device by means of which heat can be removed from or supplied to the coating fluid. 
     
     
         7 . The installation according to  claim 1 , wherein there is provided an additional counter-container circuit which comprises a pump without any seals, in particular a diaphragm pump, by means of which the coating fluid can be conveyed from the dip tank to a counter-container and back again. 
     
     
         8 . The installation according to  claim 1 , wherein the filtrate connection of the filtration device is at least indirectly connected to a cleaning tank, in which the objects are cleaned after the coating operation. 
     
     
         9 . The installation according to  claim 8 , wherein there is interposed between the filtrate connection and the cleaning tank a buffer store in which filtrate which accumulates at the filtrate connection is retained for cleaning purposes. 
     
     
         10 . A method for coating objects, comprising:
 a) immersing objects in a dip tank which is filled with a coating fluid,   b) circulating and filtering the coating fluid in the dip tank by
 removing at least a portion of the coating fluid from the dip tank; 
 filtering the coating fluid which has been removed from the dip tank in a filtration device, whereby a retentate accumulates at a retentate connection and a filtrate accumulates at a filtrate connection; and 
 circulating the coating fluid which is present in the dip tank by returning the retentate from the retentate connection to at least one circulation outlet which is arranged in the dip tank. 
   
     
     
         11 . The installation according to  claim 6 , wherein the temperature control device is a heat exchanger. 
     
     
         12 . The installation according to  claim 6 , wherein the temperature control device is arranged upstream of the filtration device. 
     
     
         13 . The installation according to  claim 9  wherein the cleaning purposes are manual cleaning purposes.