Digital Technology

Digital Technology
Using variable frequency drives reduces annual energy costs

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Software allows for full-featured SCADA at small utility

Problem: The water and wastewater utility in Jack, Alabama, faced pressure to reduce costs while providing safe and reliable service. The community could not afford a SCADA system such as large municipalities use.

Solution: JMJ Automation used the no-cost VTScadaLIGHT license from Trihedral to develop a full-featured SCADA application. “Many utilities only need to monitor one well and one tank,” says JMJ president Jason Bell. “VTScadaLIGHT allows us to reach out to small customers who, without it, would not be able to afford SCADA at all.” Operators visit the well and tank once a day per state requirements. Now they can check levels and manage alarms anytime from their Windows 10 workstation or mobile devices.

Result: The program includes a development and runtime interface for applications up to 50 I/O. It provides a mobile connection, alarms, trends, reports, security, redundancy, open connectivity and drag-and-drop screen development. “They can get alarms right away and use historical data to do things like check if a pump is running more now than it has been,” says Bell. 800/463-2783;

Portability of electromagnetic flowmeter enables city to track multiple valves

Problem: A Colorado city needed to measure flow through three valve chambers to determine whether the water load was shared equally. The operator can use the flow data to decide whether to adjust the pressure setpoints on the pressure-reducing valves in each vault. The city needed a portable meter that could be shared between three valves in separate chambers.

Solution: The city chose Singer Valve’s SPI-MV for its single-point insertion probe that can be inserted into the valve and then moved to a different valve. The flowmeter was combined with a data logger and 12-volt DC lithium battery to allow it to remain in the vault for a month to acquire and save data, which is then transferred via USB.

Result: The flowmeter is accurate to 2 percent of reading throughout the specified velocity range. This lets operators confidently monitor the flow and compare loads to ensure equal flow. 888/764-7858;

Using variable frequency drives reduces annual energy costs

Problem: The City of Cedarburg Wastewater Treatment Facility in Wisconsin was running its aeration system in a costly and inefficient manner. The system had been using soft starters to control six motors (75 and 50 hp). One of the aerators would kick on every 15 minutes at 100 percent and run for a period of 15 to 60 minutes, depending on the dissolved oxygen in the third channel of the ditch. A second aerator would come on for 15 minutes every hour and run at 100 percent. An average of three to four aerators ran at a time.

Solution: The existing motor control centers would be retrofitted using ABB variable-frequency drives (VFD). JMB & Associates conducted a review of the existing motors for full load amps, running amps, motor lead lengths, conduit runs, and motor construction for VFD compatibility. It was determined the VFDs would provide motor speed, motor load, VFD temp, individual fault ID, fault reset, kWh, run status and speed command information to the interface.

Result: Floc size and settling rates increased, less chemical supplementation was needed, and energy bills were lowered. Operators also observed reduction of mechanical stresses on equipment linkage points owing to precise motor acceleration and deceleration. Ultimately, the city reduced their annual energy cost by 30 percent. 800/752-0696;

Heater and control unit prevent freezing in wastewater tanks

Problem: Filtration membranes in two wastewater treatment tanks at an Iowa ethanol producer were susceptible to freeze damage. Each membrane is valued at $1 million, and  freezing could mean full replacement and loss of production. The tanks are part of a closed-loop system that holds thousands of gallons of water used in ethanol production.  

Solution: A modified Chromalox TLI L-shaped metal heater was installed in each tank. Each 480-volt heater holds two tiers of three elements and is controlled by a 4468 Contactor Panel. The systems maintain the water at 40 to 50 degrees F. The company also purchased a third heater/contactor as a backup.

Result: The system prevents membrane freezing and ensures that the facility remains in production. It also provides energy savings. 800/443-2640;


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