| 摘要 |
<p>A spiral impeller pump, with vertical shaft and variable speed/direction drive motor is placed at the bottom of an outer cylindrical container and surrounded by an inner cylinder whose base has slotted walls and which reaches only partly to the top of the outer. The annular gap is filled with esp. glass balls, 3-5 mm in dia., and below these is an aerator pipe for agitation of the balls during cleaning. A filter is fitted over the top of the inner tube. Large effective culture growth area; easy to clean and maintain.</p> |
