Since 2000, Entech Design, Inc. has used underwater acoustic sensing technology to monitor filter media expansion. Expansion Pro Analyzer 2000™, an application specific instrument designed to measure media expansion in granular media filters, employs the same underwater sensing technology that Entech Design has applied in sludge blanket and other industrial interface level analyzers since 1991. The instrument monitors media expansion levels as a percent of media bed depth during filter backwash, as well as media level and loss in between wash cycles.
Monitoring backwash expansion is vital to optimizing filter performance. Optimal expansion produces two key process effects: (1) fully fluidizes media grains allowing impurities deep in the filter to release, and (2) promotes aggressive particle agitation which is required to remove sticky floc and dislodge material attached to media grains. Optimal expansion also prevents costly media loss.
A properly maintained filter not only produces high quality water, but it is also more likely to have longer filter run times and reduced annual backwash cycles. Over time, using EPA 2000 to optimize media expansion levels can save a plant money, time, and wear and tear on expensive process equipment.
EPA 2000 is designed for both process monitoring and active process control, and is capable of operating one to four sensors or transducers from one analyzer. Recent installations have also included ground water pressure filters.