REJUVENATING WATER TREATMENT PLANTS.
Municipalities are giving their aging water treatment plants a new lease on life by using control technology that was unknown when the plants were built.
One example is the 47-year-old water treatment plant that serves the city of Bismarck, N.D.
The city's engineering department planned to install a networked automation system to operate the valves that send 26 million gallons of water per day into the plant's filter beds. Engineers decided to use an Allen-Bradley PLC-5, containing a ProSoft 3100-LTQ interface module, to preside over a Limitorque DDC-100 redundant loop network. The network directs Accutronix MX electronic valve actuators, made by Limitorque Corp. of Lynchburg, Va.
Charlie Jaszkowiak, superintendent of the Bismarck water treatment plant, said that the new actuators' interface module eliminated the need for a proprietary master control station.
Operators at the Bismarck plant program the Limitorque actuators by touch-screen control panels that replaced bulkier pushbutton cabinets. Every control panel stands adjacent to each filter so that operators are able to change individual actuator parameters, and also view operational data in real time.
Based on the successful performance of the first seven Accutronix MX actuators, the city of Bismarck added 107 more actuators, with plans for more than 150, and a second DDC-100 network to serve new filter beds that will treat an additional 40 million gallons per day.