Road sweeping machine including an improved filter device

Abstract

A disclosed road sweeping machine ( 1 ) including a filter device ( 6 ) and comprising: movement means ( 2 ), suitable to allow movement of the road sweeping machine ( 1 ), collection means ( 3 ), suitable to allow collection of refuse and air including pollutants from the outside environment, a container ( 4 ), suitable to contain the refuse and the pollutants, means ( 5 ) for conveying the air from the container ( 4 ) to the outside environment and wherein the filter device ( 6 ) is suitable to filter the air conveyed from the conveying means ( 5 ) and comprises a filter layer ( 7 ) having a filter membrane ( 7 a ) provided with a first membrane ( 7 b ) made of polytetrafluoroethylene.

1 . Road sweeping machine ( 1 ) comprising an improved filter device ( 6 ) and comprising: movement means ( 2 ), suitable to allow movement of said road sweeping machine ( 1 ), collection means ( 3 ), suitable to allow collection of refuse and air including pollutants from the outside environment, a container ( 4 ), suitable to contain said refuse and pollutants, means ( 5 ) for conveying the air from said container ( 4 ) to the outside environment in which said filter device ( 6 ) is suitable to filter the air conveyed from said conveying means ( 5 ) and comprises a filter layer ( 7 ) including a filter membrane ( 7   a ) provided with a first membrane ( 7   b ) made of polytetrafluoroethylene. 
   
   
       2 . Machine according to  claim 1 , wherein said first membrane ( 7   b ) is made of expanded polytetrafluoroethylene. 
   
   
       3 . Machine according to  claim 2 , wherein said first membrane ( 7   b ) has a microstructure of knots interconnected by yarns. 
   
   
       4 . Machine according to  claim 3 , wherein said first membrane ( 7   b ) has a microstructure of knots interconnected by yarns disposed substantially in parallel directions. 
   
   
       5 . Machine according to  claim 1 , wherein said filter membrane ( 7   a ) comprises a second membrane ( 7   c ), adjacent to said first membrane ( 7   b ). 
   
   
       6 . Machine according to  claim 5 , wherein said second membrane ( 7   c ) is made of needle felt in polymer material. 
   
   
       7 . Machine according to  claim 5 , wherein said filter membrane ( 7   a ) is disposed with said membrane ( 7   b ) facing said container ( 4 ), so that said air flow passes in succession through said first membrane ( 7   b ) and said second membrane ( 7   c ). 
   
   
       8 . Machine according to  claim 1 , wherein said filter layer ( 7 ) is realized by a bag filter. 
   
   
       9 . Machine according to  claim 1 , wherein said filter device ( 6 ) comprises a selection filter ( 8 ) suitable to filter the air conveyed towards said filter layer ( 7 ). 
   
   
       10 . Machine according to  claim 9 , wherein said selection filter ( 8 ) is realized by a metal grate. 
   
   
       11 . Machine according to  claim 1 , comprising a system ( 9 ) for cleaning the filter layer ( 7 ). 
   
   
       12 . Machine according to  claim 11 , wherein said cleaning system ( 9 ) comprises a rod element ( 9   a ), made to rotate around an axis ( 9   b ) and eccentric with respect to said rotation axis ( 9   b ), so that at least a portion having a greater distance from said rotation axis  9   b  is in interference with said filter layer ( 7 ).