Hydraulically dynamic mono-pig scraper

Abstract

The invention concerns a pig scraper for cleaning the inside wall of a coating agent conduit. The pig scraper includes a body insertable in the conduit and at least one sealing lip that seals against the inside wall of the conduit and extends parallel to a longitudinal axis of the body. A space is defined between the sealing lip and the body to form a pocket for enhancing the sealing of the sealing lip with respect to the conduit. The length of the sealing lip substantially prevents the lip from folding over on itself in response to a change in the direction of movement of the pig scraper in the conduit.

What is claimed is:  
     
         1 . A pig scraper for cleaning a coating agent conduit of a coating unit comprising: 
 a body having a length and a longitudinal axis; and    at least one sealing lip extending from said body substantially parallel to a longitudinal axis of said body.    
     
     
         2 . The pig scraper of  claim 1  wherein said body and said at least one sealing lip are integrally formed with respect to one another.  
     
     
         3 . The pig scraper of  claim 1  wherein at least a portion of said at least one sealing lip extends parallel to and spaced from said body.  
     
     
         4 . The pig scraper of  claim 1  including a sealing edge extending radially from said at least one sealing lip.  
     
     
         5 . The pig scraper of  claim 1  wherein said body extends axially beyond said at least one sealing lip.  
     
     
         6 . The pig scraper of  claim 1  including a signal transmitter operably associated with said body.  
     
     
         7 . The pig scraper of  claim 6  wherein said body is formed with said signal transmitter positioned in situ.  
     
     
         8 . The pig scraper of  claim 7  wherein said body is formed from one of a water lacquer resistant material and a solvent resistant material.  
     
     
         9 . The pig scraper of  claim 8  wherein said signal transmitter is formed from one of steel and a permanent magnet.  
     
     
         10 . The pig scraper of  claim 1  wherein said at least one sealing lip extends a first axial distance relative said body and a second distance radially from said body and said second distance is 10% of said first distance.  
     
     
         11 . The pig scraper of  claim 1  wherein said at least one sealing lip defines a free length extending axially from said body and said free length being at least 6% of said length of said body.  
     
     
         12 . The pig scraper of  claim 1  including a coating agent conduit sized to receive said body and said at least one sealing lip.  
     
     
         13 . The pig scraper of  claim 12  wherein said body defines an outside diameter and said outside diameter being 80% of said inside diameter of said coating agent conduit.  
     
     
         14 . The pig scraper of  claim 12  wherein said at least one sealing lip defines a free length extending axially from said body and said free length being at least 15% of said inner diameter of said coating agent conduit.  
     
     
         15 . The pig scraper of  claim 12  including a sealing edge extending radially from said at least one sealing lip wherein said sealing edge defines a first surface extending between 25 and 65 degrees relative to said inner wall of said coating agent conduit.  16 . The pig scraper of  claim 15  wherein said sealing edge defines a second surface adjacent said first surface and extending 10 and 60 degrees relative to said inner wall of said coating agent conduit.