| 摘要 |
The foaming of the filter is carried out without emptying, the water remaining over the filter. There is a motorised bridge which runs on rails above the sand bed. There is a scraper which can be raised and lowered and moves through the bed. The scraped material and water is sucked out via the nozzle by a suction device to a collection channel form which water is pumped to a storage vessel. The arrangement can be moved from one filter basin to another with a winch. (Provisional Basic previously advised in week 8510)(0/4) |
