| 摘要 |
<p>A pipe has an internal pressure sleeve (14) for carrying hydrocarbons, an external sleeve (24) and one or more reinforcing layers (16, 18, 20) between the internal and external sleeves. The permeation gases which diffuse through the wall of the internal sleeve are forced to circulate through channels along the reinforcing layers towards means of evacuation. The reinforcing layer(s) (16, 18, 20) are placed in an annular zone between the internal and external sleeves. A carrier gas is injected under pressure into the annular zone in a number of injection zones to force the permeation gases to circulate in the channels towards the means of evacuation. The carrier gas is injected at one end of the flexible pipe and the gas contains nitrogen. Alternatively, circulation is created by extracting the permeation gases in at least one aspiration zone inside the annular zone. An independent claim is included for a flexible pipe designed to allow this process to take place, with an internal pressure sleeve (14) through which the permeation gases diffuse; an external sleeve (24) and one or more reinforcing layers (16, 18, 20) placed in an annular zone. The pipe includes means (22) of forcing circulation of the permeation gases through channels in the annular zone, comprising at least one supply of carrier gas under pressure opening into the annular zone. This supply has injection orifices spaced apart from each other to form a number of injection zones spaced along the pipe. Alternatively, the means of forcing circulation are means of drawing the gases in various aspiration zones along the pipe. These are differential valves designed to evacuate the gases by pressure difference between the annular zone and the exterior.</p> |
