| 摘要 |
<p>The invention relates to an apparatus for aerating media such as liquid manure and the like. It consists of an elongated, flexible hollow element (1) made of a polymeric substance which has a connecting piece for allowing gaseous substances to be fed to the hollow space. The wall of the hollow element has openings (13) which are provided around the circumference and spaced from each other in a predetermined fashion, which openings are closed in the unloaded state and open to allow gas to pass out when the hollow space is charged with a pressure. The characteristic of the invention consists in the fact that the wall of the hollow element is composed of at least two layers (11, 12). The internal layer (11) is composed of soft polyvinyl chloride, and the external layer (12) is a permanently flexible coating. Both layers have relative thicknesses of 1:1 to 1:20, preferably 1:5 to 1:10. <IMAGE></p> |
