| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an apparatus for dredging the surface of a sand filter bed of a sand filter tank in a relatively small-scaled water cleaning system, for the purpose of solving such a problem that the surface of a sand bed is dredged by a sand scraper and the surface of the sand bed is flatly and uniformly leveled by a leveling rod but, in the relatively small-scaled water cleaning system, the sand filter tank is small and, these tools are hardly used. SOLUTION: The apparatus for dredging the surface of the sand filter bed is constituted of the guide body having a pair of parallel guide sides extending in a longitudinal direction to be placed on the surface of the sand filter bed and a dredger guided by a pair of the parallel guide sides to dredge the surface of the sand filter bed over a predetermined thickness.</p> |
