Method and device for cleaning a dirty surface

Abstract

A method and a device_for cleaning a dirty surface, wherein water is squirted from a nozzle against the dirty surface in order to wash away the dirt with the water, characterized in that compressed air is supplied to the water in a mixing chamber, which is located upstream of the nozzle, at a predetermined pressure, after which the water is squirted against the dirty surface in a spray of droplets, downstream of the nozzle.

1 . A method for cleaning a dirty surface by squirting water in a spray of droplets against the dirty surface to be cleaned comprising the steps of:
 flowing a liquid through a central bore of a nozzle housing;   flowing a gas through a plurality of gas channels formed in the nozzle housing radially around the central bore;   mixing the liquid with the gas in a mixing chamber, wherein the mixing chamber has coaxial bore portion formed by a terminal end of the central bore and an upstream portion of a nozzle;   forming a mixture of the gas and liquid having a pressure higher than the pressure outside of the nozzle;   flowing the mixture through an exit orifice of the nozzle, wherein the exit orifice has a diameter smaller than the diameter of the upstream portion;   squirting the mixture against the dirty surface; and   cleaning the dirty surface.   
   
   
       2 . The method of  claim 1 , further comprising attaching a rotating member to the nozzle and rotating the rotating member to manipulate a direction of the mixture engaging the dirty surface. 
   
   
       3 . The method of  claim 2 , further comprising flowing the mixture through the rotating member, wherein the rotating member is coupled to a holder coupled to the nozzle. 
   
   
       4 . The method of  claim 3 , further comprising impacting one or more blades coupled to the rotating member with the mixture thereby rotating the rotating member, wherein the blades extend radially outward from a central axis of the rotating member. 
   
   
       5 . A method for cleaning a dirty surface by squirting water in a spray of droplets against the dirty surface to be cleaned comprising the steps of:
 mixing water and air under pressure in a nozzle device having coaxial bores, said nozzle having an upstream portion where the water and air under pressure are mixed to obtain a pressure for said mixture higher than the pressure outside the nozzle device;   passing said pressurized mixture of air and water to a downstream fluid port portion of said nozzle device which is narrower than said upstream portion;   squirting said spray against the dirty surface to be cleaned; and   cleaning the dirty surface with said spray.   
   
   
       6 . The method of  claim 5 , wherein pressurized water having a water pressure is supplied to said upstream portion of the nozzle device. 
   
   
       7 . The method of  claim 6 , wherein the water pressure can be regulated. 
   
   
       8 . The method of  claim 5 , wherein the spray of droplets exits said nozzle from said fluid port and is squirted against the dirty surface downstream of the nozzle. 
   
   
       9 . The method of  claim 5 , wherein the air pressure and the water pressure are set to a ratio ranging between 2:1 and 1:2, respectively. 
   
   
       10 . The method of  claim 5 , wherein the water is squirted against the surface in a spray of droplets, from a distance which is smaller than a distance at which the water becomes turbulent downstream of the nozzle due to lack of impetus. 
   
   
       11 . The method of  claim 5 , wherein the surface to be cleaned is a surface of flower bulbs, flower tubers or perennial plants and wherein a range of water pressure and a range of air pressure measured as an overpressure relative to the water pressure are selected from the following groups (i) to (v):
 (i) water pressure from 0.5 to 1.5 bar and air pressure from 8 to 8.5 bar;   (ii) water pressure from 1.5 to 3 bar and air pressure from 7.5 to 8 bar;   (iii) water pressure from 2.8 to 4.2 bar and air pressure from 5.5 to 6 bar;   (iv) water pressure from 4 to 6.2 bar and air pressure from 5 to 5.5 bar; and   (v) water pressure from 6 to 10 bar and air pressure from 3.5 to 6.5 bar.   
   
   
       12 . The method of  claim 5 , wherein the surface to be cleaned is a surface of soft fruit, and wherein a range of water pressure and a range of air pressure measured as an overpressure relative to the water pressure are selected from the following groups (i) to (ii):
 (i) water pressure from 0 to 0.5 bar and air pressure from 1.5 to 2.5 bar; and   (ii) water pressure from 0.5 to 1.5 and air pressure from 1.5 to 2.5 bar.   
   
   
       13 . The method of  claim 5 , wherein the surface to be cleaned is a surface of medium hard crops, and wherein a range of water pressure and a range of air pressure measured as an overpressure relative to the water pressure are selected from the following groups (i) to (iii):
 (i) water pressure from 2.8 to 4.2 bar and air pressure from 6.5 to 9.5 bar;   (ii) water pressure from 4 to 6.2 bar and air pressure from 6.5 to 9.5 bar; and   (iii) water pressure from 6 to 10 bar and air pressure from 6.5 to 9.5 bar.   
   
   
       14 . The method of  claim 5 , wherein the surface to be cleaned is a surface of hard crops, and wherein a range of water pressure and a range of air pressure measured as an overpressure relative to the water pressure are selected from the following groups (i) to (iii):
 (i) water pressure from 2.8 to 4.2 bar and air pressure from 9.5 to 20 bar;   (ii) water pressure from 4 to 6.2 bar and air pressure from 9.5 to 20 bar; and   (iii) water pressure from 6 to 10 bar and air pressure from 9.5 to 20 bar.   
   
   
       15 . The method of  claim 5 , wherein the surface to be cleaned is sugar beets, beetroots or potatoes, or the products stemming therefrom, potato chips, pulp and cattle fodder products and wherein the water pressure is between 6 and 10 bar and the air pressure has an overpressure of 4.0 to 20 bar relative to said water pressure. 
   
   
       16 . The method of  claim 5 , wherein the surface to be cleaned is a surface of roads, and wherein the water pressure is between 6 and 10 bar and the air pressure has an overpressure of 7 to 20 bar relative to said water pressure. 
   
   
       17 . The method of  claim 5 , wherein the surface to be cleaned is vehicles, passenger cars in a car wash; or trains, buses or lorries in special washing facilities, and wherein the water pressure is between 0.5 and 1.5 bar and the air pressure has an overpressure of 2.5 to 6 bar relative to said water pressure. 
   
   
       18 . The method of  claim 5 , wherein the surface to be cleaned is a surface of crockery, cutlery in a dishwasher, or machines or tools in an industrial washing-up machine, and wherein the water pressure is between 0.5 and 1.5 bar and the air pressure has an overpressure of 4.5 to 8 bar relative to said water pressure. 
   
   
       19 . The method of  claim 5 , wherein the surface to be cleaned is a surface of persons, and wherein a range of water pressure and a range of air pressure measured as an overpressure, relative to the water pressure are selected from the following groups (i) to (iii):
 (i) water pressure from 0.5 to 1.5 bar and air pressure from 1.5 to 5; and   (ii) water pressure from 1.5 to 3 bar and air pressure from 1.5 to 5.   
   
   
       20 . The method of  claim 5 , wherein the surface to be cleaned is hard surfaces, and wherein the water pressure is between 6 and 10 bar and the air pressure has an overpressure of 9.5 to 20 bar relative to said water pressure.