Impact Of Improved Actuation On Filter Performance

A Water Filtration Treatment Plant purifies water from the Mississippi River and supplies drinking water to city residents. Plant personnel are constantly working to improve processes in an effort to exceed stringent state and federal regulations. The plant removes particulate matter from the river water using eight mixed media rapid gravity filters.

When the filter plant was built in 1950, pneumatic actuators were installed on all of the filter control valves. The pneumatic actuators were not always reliable. Air compressor problems limited the availability of the pneumatics to control the filter valves. As a result of the instrument air problems, the pneumatic actuators were replaced in 2003 with conventional electric actuators on the filter control valves throughout the facility. Many water treatment plants use conventional electric actuators because they are widely available and commonly supplied as part of bigger systems. Unfortunately, conventional electric actuator designs use high speed induction motors as the driving force.