摘要 |
<p>Main water stream is fed through a metering apparatus and moves the vaned wheel which, with an endless screw, is on the shaft of an agitator, so that the phosphate solution in the space (at the bottom of the shaft) is homogenised and injected in metered fashion into the stream, while fresh water is fed by a secondary stream into the phosphate space (around the shaft). Apparatus is described. Specif. precipitation of hardness salts is prevented and metal corrosion is reduced.</p> |