Plant upgrades gas flowmeter at reclamation facility

Problem:

The Tres Ríos Water Reclamation Facility serves Tucson, Arizona, and treats 30 mgd. This recently modernized treatment plant has a capacity of 50 mgd. Plant engineers sought to upgrade their gas flowmeters that measure biogas-feeding burners heating multiple hot-water boilers. The meters measure methane from multiple digester tanks that fuel the boilers to provide hot water and steam.

Solution:

FCI - Fluid Components International recommended installing its ST80 Series thermal flowmeter, which is suitable for biogas service. It features Adaptive Sensor Technology, which offers enhanced accuracy and repeatability in wastewater environments. This meter offers a hybrid sensor drive that combines constant power and constant temperature thermal dispersion sensing technologies. When in AST mode, the meter measures in constant temperature during startup through the lower flow ranges and then shifts into constant power mode at the midrange and at higher flow rates. The meters are installed on 8-inch-diameter pipes, Schedule 10S. They will measure flow rate and totalized flows. The range desired was 37 to 500 scfm, with 170 scfm typical, at temperatures from 78 to 110 degrees F, with 95 degrees F normal at pressures of 30 psig.

RESULT:

Plant engineers were pleased with the meter’s accuracy of plus or minus 1% of reading, plus or minus 0.5% of full scale, and repeatability of plus or minus 0.5% of reading. The turndown ratio is a minimum of 2-1 up to 100-1, which accommodates demand swings. The flow range also met their biogas application needs. 800-854-1993; www.fluidcomponents.com.

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City improves water treatment monitoring

Problem:

The City of Haverhill (Massachusetts) Water Division serves 58,000 residents and businesses and produces 2 billion gallons of water per year. The plant is manned continuously. Water comes from three sources; the city needed to better monitor water treatment and maintain high quality.

Solution:

GE Digital’s iFIX allowed the city to move to a computerized process environment, giving it a cohesive system to follow procedures and respond to events in a consistent and sequenced manner. Management went further by purchasing laptops for on-call operators, enabling them to control operations from any location.

RESULT:

The move has given the plant more flexibility and reduced cost. “With iFIX, you can dial in the plant, get it set up and don’t have to watch it as closely,” says John D’Aoust, plant manager. “The team has all the features of the control room in their hands.” 800-433-2682; www.ge.com/digital.

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Sanitary sewer system updated with remote monitoring capabilities

Problem:

The Minneapolis Public Works Department needed to modernize the sanitary sewer system to meet the city government’s goals. Minneapolis had nine sanitary lift stations and 23 storm sewer pump stations spread throughout the city. None of the stations had remote monitoring capabilities, and the Public Works Department wanted to add this capability.

Solution:

PRIMEX was chosen as the prime contractor to retrofit the existing stations by adding remote monitoring capabilities. The mandate was to develop and install a complete SCADA system that included the addition of digital cell routers on the Verizon network to improve monitoring. The upgraded system also incorporated a local computer memory at each site, ensuring that if for any reason the cell connection was down, the data would not be lost. The local Wonderware Edge graphical operator interface has native capabilities to both store and forward all data. When the Verizon communications are lost, the local OIT logs data to memory. Upon restoration of cellular communications, all of the historical information is backfilled into the historian so that there are no blackouts in data. This redundancy feature is the first of its kind and was successfully implemented for the city.

RESULT:

The sanitary sewer system is now able to meet the department’s goals. Remote monitoring was added to all systems and helped improve their data analytics and enhance their ability to more effectively manage both storm sewers and sanitary sewers. 844-477-4639; www.primexcontrols.com.