Tubular Backwash Filters Operation

Durco Filters Tubular Backwash Filters are designed for continuous operation. This is accomplished by configuring the filter system with multiple tubes which all have forward flow while in normal operation. When a specific pressure differential is reached between the inlet and outlet, the filter enters cleaning mode. During cleaning, one filter tube at a time is brought off line and back-flushed (backwashed). The back-flushing removes the contaminants from the permanent, reusable media and washes them to drain. While the individual tube is backwashing, the rest of the tubes maintain full forward flow.

The liquid used to backwash the filter can come either from the filtrate, Internal Backwash, or from a separate source, External Backwash. The backwash liquid can be disposed of or sent to a filter press for dewatering.

Internal Backwash Operation

Internal backwashing systems use the system’s filtrate to clean the tubular filter media. Internal Backwash Mode should be considered when the process stream is: Of sufficient flow and pressure to ensure an adequate backwash Inexpensive and does not create a disposal problem

External Backwash Operation

External backwashing systems use a clean, secondary stream (such as plant water) supplied by an additional header to clean the tubular filter media. External Backwash Mode should be considered when the process stream is: Not of sufficient flow and pressure to ensure adequate internal backwash Valuable, or if it creates a disposal problem

Manual or Automatic Operation

Durco Filters Tubular Backwash Filters can use either manual or automatic operation. For systems with only two or three tubes and infrequent need for cleaning, manual operation might be appropriate.

For most systems, fully automatic operation is desired. PLC control eleminates operator involvement. The filter enters cleaning mode automatically and puts itself back into normal filtration mode.