Erema RTF piston screen changers are different from widely-available conventional systems due to their completely automatic partial area backflushing system. Thanks to their unique design (pressure balanced double screen design per piston) Erema partial area backflush systems function extremely well with a wide range of filtering requirements.
The characteristics of Erema partial area backflush systems can be summarised as follows:

• Minimises influence on downstream processes thanks to lowest pressure fluctuations during backflushing and screen changing (RTF 4 and RTF 8).
  
  
• Efficient, reliable backflushing mechanism (optionally in VC-configuration) with very short backflush channels. This dramatically increases screen service life and keeps backflushing material losses to a minimum.
  
  
• Back purging is triggered completely automatically, reducing operator requirement.

Partial surface backflushing technology involves flushing a comparatively small area of the screen surface in relation to the total active screen area by passing a central stream of clean melt through from the back of the screen. High velocity is possible at the screen due to the small surface area of screen to be flushed (in particular with VC-configuration) at a time, resulting in optimum cleaning efficiency. It is also possible to adjust the backflushing stream, using a replaceable throttle nozzle on the clean side of the filter (preventing risk of clogging with contamination!), adapting the system to individual requirements. The large total screen area that remains active even during backflushing and screen changing and the correct match of throttle nozzle enable this system to be implemented even with sensitive downstream processes.