After 34 years of operation, we last spring changed a debris filter unit model Taprogge PR-BW 400 to a newer unit with improved design of model Taprogge PR-BW 800. The filter is installerad in a power plant on the Swedish east coast and has been in operation since may. Taprogge’s model name PR-BW is short for Pressure Relief Back Wash, where a rotating arm attached to an outlet in the centre covers the filter surface. The outlet which is connected down stream of the heat exchanger to be protected, thus creates a pressure drop which automatically sucks off the filter surface