Backwashable filter device having means to add additional fluids to filtrate backwash fluid

摘要

The invention concerns a backwashable filter device, specially for domestic water conduits that includes an inlet for raw water, a raw water chamber connected to the inlet, an outlet for clean water, a clean water chamber connected to the outlet, a filter element and an outlet for backwash water. The filter element is arranged between the raw water chamber and the clean water chamber and features a partial area (B) that accommodates water flow only in backwash but not normal operation. A conduit channel connects the outlet for backwash water with the partial area (B). At least one separate conduit connection is provided from the clean water chamber to the partial area (B). A conduit area is present in the conduit connection and designed in a nozzle-like shape so that clean water can be conducted from the clean water chamber at increased velocity against the partial area (B).