Apparatus for cleaning surfaces

Abstract

The apparatus for cleaning surfaces comprises a body ( 1 ) comprising a tank ( 2 ) for containing an abrasive material and a first duct ( 19 ) for a flow of compressed air which extends adjacent to said tank ( 2 ) along the whole length of said tank ( 2 ). The apparatus comprises as well a mixing valve ( 31 ), associated with said tank ( 2 ), for mixing said abrasive material with said compressed air.

1 . An apparatus for cleaning surfaces, the apparatus comprising:
 a body comprising a tank for containing an abrasive material and a first duct for a flow of compressed air, said first duct extending adjacent to said tank along a whole length of said tank;   a mixing valve, associated with said tank for mixing said abrasive material with said compressed air;   a sprayer means for connecting with said mixing valve, said first duct being predisposed for allowing said flow of said compressed air both directly into said tank to allow storage of said abrasive material inside said tank, and said flow of said compressed air towards said mixing valve, said mixing valve comprising a first inlet duct for passage of said flow of compressed air;   a central duct extending along a central axis, shaping a mixing chamber and communicating with said first inlet duct,   a second inlet duct for passage of said abrasive material, said second inlet duct communicating with said central duct, said second inlet duct extending along a longitudinal axis inclined with respect to said central axis of said central duct of an acute angle;   a conveying member mounted inside said tank, in a lower position, having a hollow conical shape being asymmetric with respect to a revolution axis of said conveying member.   
     
     
         2 . An apparatus according to  claim 1 , wherein said conveying member defines a receiving opening in an upper part of said conveying member for said abrasive material contained in said tank and an opposite eccentric opening towards which said abrasive material is conveyed. 
     
     
         3 . An apparatus according to  claim 1 , wherein said acute angle is comprised in a range between 30° and 45°. 
     
     
         4 . An apparatus according to  claim 1 , wherein said sprayer means has a spraying nozzle at one end of said sprayer means, said nozzle being predisposed to spray said flow of compressed air mixed with said abrasive material on a surface to be treated, said nozzle comprising a hollow cylindrical body having an inlet opening and an opposite outlet opening. 
     
     
         5 . An apparatus according to  claim 4 , wherein said spraying nozzle comprises a portion having a narrowing of transversal section from which a guide channel having a shape diverging towards said outlet opening is defined for said flow of compressed air and said abrasive material. 
     
     
         6 . An apparatus according to  claim 5 , wherein said guide channel diverges of an another acute angle with respect to a longitudinal axis of said spraying nozzle so as to spray a jet having a substantially conical shape with a homogeneous distribution of said abrasive material in a volume of said jet. 
     
     
         7 . An apparatus according to  claim 6 , wherein said another acute angle is comprised in a range between 2° and 8°. 
     
     
         8 . An apparatus according to  claim 1 , further comprising:
 a shutter member, arranged inside said second inlet duct, associated with a regulation valve, which allows a transversal section of said second inlet duct to adjust upon activation of said regulation valve.