Filter Design
One design brings the water in the top of a container through a "header" which distributes the water evenly. The filter "media" start with fine sand on the top and then graduatingly coarser sand in a number of layers followed by gravel on the bottom, in gradually larger sizes. The top sand physically removes particles from the water. The job of the subsequent layers is to support the finer layer above and provide efficient drainage.
Read more about this topic: Media Filter
Famous quotes containing the word design:
“I begin with a design for a hearse.
For Christ’s sake not black—
nor white either—and not polished!
Let it be weathered—like a farm wagon—”
—William Carlos Williams (1883–1963)