| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a wall surface cleaning method by which a stubbornly adhering foreign substance can be removed by low jet pressure, when the wall surface of a duct is cleaned by spewing high pressure fluid from a nozzle. SOLUTION: The wall surface 18 to be cleaned is covered with a covering lid 20 so that two opposed sides 20a and 20b come into contact with each other and the intermediate part is separated apart to form a space 21, at least one opening 21a is formed in the space 21 and a high pressure hose 14 inserted into the space 21 from the opening 21a is rotated around the center axis of the hose 14. Further, the hose 14 is moved back and forth in the center axial direction and the high pressure fluid is spewed from a plurality of jet apertures 15a and 15b with different diameters which are perforated in an orthogonal direction with the advancing/receding direction of a nozzle 15 fitted to the tip of the rotary high pressure hose 14. Thus the nozzle 15 is spirally moved by jet pressure difference in such a state that the nozzle 15 is set in close proximity with the inner wall surface of the space 21 and the wall surface 18 is cleaned by the spewed high pressure fluid.</p> |
