| 摘要 |
<p>A process and device are disclosed for applying a free-flowing material to the inner surface of a tube blank. The material is applied to the inner surface by means of a carrier gas stream, provided with a swirl, conducted through the hollow space. To prevent or reduce swirl loss, which occurs if the laden carrier gas stream, provided with the swirl, forces stagnant air in the hollow space from this space and then the loss develops by friction on the inner surface, before and during the flow of the laden carrier gas provided with the swirl, an additional gas, not laden with the material, is conducted through the hollow space with a swirl, having a direction of rotation which corresponds to the swirl of the laden carrier gas stream. For this purpose, the device is provided on the outlet of a passage element equipped with a swirl-producing device for the laden carrier gas stream, with outlet nozzles which feed to the laden carrier gas stream the additional gas with a swirl, having a direction of rotation corresponding to that of the swirl-producing device.</p> |
