| 摘要 |
<p>Apparatus for spraying a powder circumferentially around a pipe joint on a pipe comprising a yoke engagable with the pipe, one or more powder dispensers mounted on the yoke and disposed over the pipe joint, means for driving the yoke circumferentially about the pipe, each powder dispenser having an inner housing provided with an opening positioned adjacent the surface of the pipe for supplying a quantity of air-powder suspension to the surface of the pipe over the pipe joint, each powder dispensing device also having an outer housing surrounding the inner housing and being provided with an opening positioned adjacent the pipe and surrounding the opening of the inner housing, the inner and outer housings of each powder dispenser defining a space therebetween. A powder suspension device is provided having a hollow container adapted to contain a quantity of powder therein and a means for introducing air under pressure adjacent the bottom of the container to place the powder in suspension in the container. A blower is also provided having an inlet and a tangential outlet from which a stream of air emerges. A powder return housing is located beneath the blower and above the powder suspension device and in communication with both of these devices. A pair of tangential inlet pipes arranged approximately 180 DEG apart on the return housing are adapted to return excess powder from the powder dispensing devices.</p> |
