Pressure relief system for paint circulation applications

Abstract

A paint circulation system ( 10 ) for automotive coating applications presents a paint supply source ( 18 ) and a pump ( 20 ) for pumping the paint. A circulation line ( 16 ) is fluidly communicated with the paint supply source ( 18 ) and circulates the paint at an operational pressure. A relief line ( 28 ) has a pressure relief device ( 30 ) adaptable for withstanding a predetermined pressure of the paint and to circulate the paint through the relief line ( 28 ) as the operational pressure exceeds the predetermined flow pressure. A pressure control mechanism is operatively communicated with the circulation line ( 16 ) and the relief line ( 28 ). The pressure control mechanism senses the operational pressure to continuously circulate the paint in the relief line ( 28 ) in response to a difference between the operational pressure and the predetermined pressure before the operational pressure exceeds the predetermined pressure thereby preventing the pressure relief device ( 30 ) from actuating.

1 . A closed loop circulation system for providing paint to a paint applicator comprising; 
 a circulation line fluidly communicating with the paint applicator thereby providing paint at an operational pressure to the paint applicator,    a relief line separable from said circulation line by a pressure relief device for reducing the operational pressure of the paint circulating through said circulation line when the operational pressure inside said circulation line increases beyond a predetermined value, and    a second pressure relief device cooperable with said first pressure relief device wherein said second pressure relief device actuates in response to a difference between a second predetermined pressure and the operational pressure thereby preventing said first pressure relief device from actuating.    
   
   
       2 . A closed loop circulation system as set forth in  claim 1 , including a controller operatively communicating with said second pressure relief device for actuating said second pressure relief device as the operational pressure exceeds the second predetermined pressure.  
   
   
       3 . A closed loop circulation system as set forth in  claim 2 , wherein said second pressure relief includes a pressure control sensor for sensing differences in the operational pressure with said pressure control sensor operatively communicated with said circulation line.  
   
   
       4 . A closed loop circulation system as set forth in  claim 3 , wherein said second pressure relief includes a valve fluidly communicated with said relief line and operatively communicated with said pressure control sensor for continuously circulating the paint in said relief line before the operational pressure exceeds the predetermined pressure.  
   
   
       5 . A closed loop circulation system as set forth in  claim 4 , wherein said valve is a ball valve.  
   
   
       6 . A closed loop circulation system as set forth in  claim 5 , including an actuating device cooperable with said valve for activating when signaled by said controller.  
   
   
       7 . A closed loop circulation system as set forth in  claim 6 , wherein said actuating device includes an actuator for pneumatically opening and closing said valve and a solenoid valve for energizing said actuator, said solenoid valve and said actuator presenting an operative communication with said controller.  
   
   
       8 . A closed loop circulation system as set forth in  claim 7 , including a pressure regulator cooperable with said actuator for regulating amount of air pressure supplied to said actuator.  
   
   
       9 . A closed loop circulation system as set forth in  claim 8 , wherein said pressure relief device comprises a rupture disc.  
   
   
       10 . A closed loop circulation system as set forth in  claim 9 , including a sight tube fluidly communicated with and disposed in said relief line thereby allowing visible verification that said the paint being circulated through said relief line.  
   
   
       11 . A closed loop circulation system as set forth in  claim 10 , wherein said relief line is disposed upstream in said circulation line from a first valve disposed in said circulation line.  
   
   
       12 . A closed loop circulation system as set forth in  claim 1 , including a paint supply source fluidly communicating with said circulation line for storing the paint.  
   
   
       13 . A closed loop circulation system as set forth in  claim 1 , including a pump for pumping the paint delivered from said paint supply source at the operational pressure.  
   
   
       14 . A closed loop circulation system as set forth in  claim 1 , including at least one paint booth cooperable with said circulation line.  
   
   
       15 . A paint circulation system for coating applications having a paint supply source and a pump for pumping paint, said paint circulation system comprising: 
 a circulation line fluidly communicating with the source of paint supply for circulating the paint at an operational pressure;    a relief line having a pressure relief device adaptable for withstanding a predetermined pressure being higher than the operational pressure and for circulating the paint through said relief line as the operational pressure exceeds the predetermined pressure; and    a pressure control mechanism operatively communicated with said circulation line and said relief line for sensing the operational pressure and for continuously circulating the paint in said relief line in response to a difference between the operational pressure and a second predetermined pressure before the operational pressure exceeds the predetermined pressure thereby preventing said pressure relief device from actuating.    
   
   
       16 . A paint circulation system as set forth in  claim 15 , wherein said second pressure relief includes a pressure control sensor for sensing differences in the operational pressure with said pressure control sensor operatively communicated with said circulation line.  
   
   
       17 . A paint circulation system as set forth in  claim 16 , wherein said second pressure relief includes a valve fluidly communicated with said relief line and operatively communicated with said pressure control sensor for continuously circulating the paint in said relief line as said pressure control sensor signals difference between the operational pressure and the predetermined pressure before the operational pressure exceeds the predetermined pressure.  
   
   
       18 . A paint circulation system as set forth in  claim 17 , including a controller operatively communicated with said second pressure relief device for activating said second pressure relief device as the operational pressure exceeds.  
   
   
       19 . A paint circulation system as set forth in  claim 18 , including an actuating device cooperable with said valve for operating said valve in different operational modes of said second pressure relief device.  
   
   
       20 . A paint circulation system as set forth in  claim 19 , wherein said actuating device includes an actuator for pneumatically opening and closing said valve and a solenoid valve for energizing said actuator, said solenoid valve and said actuator presenting an operative communication with said controller.  
   
   
       21 . A paint circulation system as set forth in  claim 20 , including a pressure regulator cooperable with said actuator for regulating amount of pressure supplied to said actuator.  
   
   
       22 . A paint circulation system as set forth in  claim 21 , wherein said relief line is disposed in said circulation line upstream from a first valve disposed in said circulation line.  
   
   
       23 . A paint circulation system for coating applications having a paint supply source and a pump for pumping paint, said paint circulation system comprising: 
 a circulation line for fluidly communicating with the source of paint supply and circulating the paint at an operational pressure;    a relief line having a pressure relief device adaptable for withstanding a predetermined pressure being higher than the operational pressure and for circulating the paint through said relief line as the operational pressure exceeds the predetermined pressure; and    a pressure control sensor for sensing differences in the operational pressure operatively communicated with said circulation line and said relief line and a valve fluidly communicated with said relief line and operatively communicated with said circulation system for continuously circulating the paint in said relief line as said pressure control sensor signals difference between the operational pressure and the predetermined pressure before the operational pressure reaches the predetermined pressure thereby preventing said pressure relief device from actuating.    
   
   
       24 . A paint circulation system as set forth in  claim 23 , including a controller operatively communicated with said second pressure relief device for actuating said second pressure relief device as the operational pressure exceeds.  
   
   
       25 . A paint circulation system as set forth in  claim 24 , including an actuating device cooperable with said valve for operating said valve in different operational modes of said second pressure relief device.  
   
   
       26 . A paint circulation system as set forth in  claim 25 , wherein said actuating device includes an actuator for pneumatically opening and closing said valve and a solenoid valve for energizing said actuator, said solenoid valve and said actuator presenting an operative communication with said controller.  
   
   
       27 . A paint circulation system as set forth in  claim 26 , including a pressure regulator cooperable with said actuator for regulating amount of pressure supplied to said actuator.  
   
   
       28 . A paint circulation system as set forth in  claim 27 , including a first valve valves fluidly communicated with said circulation line and disposed downstream of said pressure control sensor.  
   
   
       29 . A paint circulation system as set forth in  claim 28 , including a filter fluidly communicated with and disposed on said circulation line, said fluid filter positioned downstream said relief line and said first valve.