Patent ID: 8268084

Claim:
A method for clearing a pipe having a pipe wall, an inlet end and one or more outlets comprising the steps of: (i) at said inlet end, forcing gas into the pipe with said outlet or at least one of said outlets open to displace pipe contents as a plug and discharge pipe contents forced through by said gas, using gas forcing means capable of maintaining an overpressure sufficient therefore at a low flow velocity; (ii) when said pipe contents have been discharged, again at said inlet end, and with said outlet or at least one of said outlets open, forcing a gas into the pipe at a lower overpressure and a higher flow velocity to clear contents remaining in said pipe after step (i); and (iii) introducing a cleaning liquid into the pipe after the gas forcing steps, wherein the pipe has at least one nozzle with an outlet opening into the pipe and the step of introducing the cleaning liquid into the pipe comprises the step of injecting the liquid through said nozzle into a high speed airflow in the pipe so that the liquid is swirled around an inner surface of the pipe as a mist of droplets that contact the pipe wall.