The Nemmeli plant in Chennai is the first desalination system in India to adopt electric actuators for plant automation in a major way. With a history rooted in providing actuation solutions for water industry applications since 1970, AUMA was selected to supply over 250 electric actuators for the landmark achievement, which will supply drinking water to residents in the southern part of Chennai, the capital city of the Indian State of Tamil Nadu.
A THIRST FOR HOPE
With over four million residents, Chennai is a major commercial, cultural, economic, and educational center. The Nemmeli plant, which occupies 20 acres (81,000 square meters) of land, has capacity to treat 2.65 million gallons (100 million liters) of sea water per day. Reverse osmosis membranes convert sea water into potable water that is supplied to Southern Chennai.
The new Nemmeli plant will be a beneficial source of water at a time when the area needs it most. A local water crisis has been building around the four major reservoirs that supply Chennai residents with their potable water. Local news outlets report that the city’s drinking water has been drying up rapidly due to a low year for rain. The Water Resources Department suspended providing water to the city from the tank in a neighboring district as officials saw that the water level had dipped to an alarming low. Desalinated water from the Nemmeli plant will replace the shortage, and restore potable water to affected areas.
HIGHLY EFFICIENT, HIGH QUALITY
Product quality, local support, and long-standing expertise supplying India’s water sector were primary reasons for AUMA India’s success in winning the confidence of plant operators and decision makers. Additionally, AUMA’s modular actuators met the brief for robust, weather resistant devices.
State-of-the-art fieldbus technology has been provided by AUMA. The company’s actuators are integrated with fieldbus interfaces which comply with the Modbus protocol used by the desalination plant’s distributed control system.  The incorporation of redundant line topology enhances security as back-up data transmission connectivity is provided for all actuators linked to the fieldbus system.
AN IMPORTANT CONTRIBUTION
Pentair Limited / VA Tech Wabag had awarded the contract to AUMA India for the supply of electric actuators for automating all valves. AUMA India is the technology provider for automating flow control valves throughout the desalination plant, and MECON Limited was the consultant for this project. The sophisticated control benefits provided by AUMA India combined with its high-performance mechanical design features deliver optimum reliability and maximum plant availability.
Shortage_2
A previous desalination installation for AUMA at the Al Taweelah sea water plant in the U.A.E.
THE ROLE OF ELECTRIC ACTUATORS
Nemmeli SWRO Desalination is a state-of-the-art desalination plant comprising seawater intake system, pre-treatment system (Disc filters and Ultra filtrations), backwashing, Reverse osmosis system (Product treatment through RO high pressure pumping and Pressure exchanger, filtering the rejected water) and post-treatment system. For efficient operation of the plant, precise water flow control is required at each stage, starting with the intake system through to the post-treatment system. This calls for speedy communication between each system for maximum plant availability. Therefore, electric actuators enabled with latest technologies were required to operate valves to control the flow of water throughout the plant. The high degree of automation provided  enhanced plant efficiencies.
FROM CUSTOMIZATION TO AUTOMATION
AUMA is known to offer locally developed customized solutions for its customers based on the project requirements. Involvement of the AUMA team with the customer from the outset enabled the company to understand the stringent project requirements and offer an optimized solution.
According to local media coverage, the plant’s operation has performed smoothly—so much so that many residents were unaware in a change in their residential water. Even those residents who knew of the new plant’s launch were unable to tell the difference between the water sourced from local aquifer or reservoirs for supply and the new desalinated water.
FINDING A TOTAL SOLUTION
From the outset, AUMA presented the experience and background of a total solution provider which ensured a system approach.
AUMA offered solutions, pre and post-bid which involved technical coordination with DCS vendors plus supplying, commissioning, troubleshooting and maintenance of the electric actuators supplied for this project. ■
_________________________________________________________________________
ABOUT THE AUTHOR
Sridhar R. is the senior manager of marketing and Sandhya Sengar is the assistant manager of corporate services for AUMA India, a subsidiary of AUMA GmbH. AUMA is a leading manufacturer and global supplier of modular electric actuators. For more information, visit www.auma.com.
_________________________________________________________________________
MODERN PUMPING TODAY, October 2013
Did you enjoy this article?
Subscribe to the FREE Digital Edition of Modern Pumping Today Magazine!
Subscribe