摘要 |
Apparatus is provided for coalescing microscopic droplets of organic (principally hydrocarbons) that are present with particles in an aqueous stream (primarily water), which avoids frequent shutdowns for backwashing. The system includes two anthracite beds (56, 58, FIG. 2) and apparatus for connecting the beds in series. Most of the time, the stream flows down (60) through the first bed and up (64) through the second bed, and to a separator, while particles (74) accumulate at the top of the first bed. When the particles begin to seriously block flow through the first bed, the flow is reversed for a period while the particles are transferred from the top of the first bed to the top of the second bed. After several minutes, the flow is reversed again, causing particles at the top of the second bed to flow to the separator for removal. |