| 摘要 |
<p>Preheated metal pipes of large dia. are coated internally by spraying with thermoplastic powder which melts on contact with the metal. A cradle is provided for the pipe and a mechanism rotates it on its horizontal axis. A mobile hopper for the powder has a mechanism for moving it parallel to the axis of the pipe between two positions outside the pipe ends. The hopper has in its bottom zone a slot for depositing the powder, parallel to the axis of the pipe. A vibrator is also connected to the hopper and the powder is fluidised by jets of compressed air, so that it flows under gravity. The hopper is supported by a cantilever beam which extends inside the pipe and parallel to it, when the pipe is on its cradle. Used for the uniform lining of large dia. metal pipes of lengths =12 m, without the risk of an explosion and without loss of powder or the need to recycle it.</p> |
