With the launch of AQUA in 2008, Alfa Laval introduced the most efficient process yet for freshwater generation. The AQUA technology cut the need for seawater in half, along with the electrical energy needed for pumping it.
As energy efficiency continues to gain focus, the technology is more relevant than ever – especially with the launch of the new AQUA Blue.
AQUA Blue, on show at Marintec China, is Alfa Laval’s next step in a long tradition of development within freshwater generation technology. AQUA Blue uses the same proven, energy-efficient desalination process as its predecessor. But it incorporates a wide range of enhancements that simplify both operation and installation.
“The AQUA technology was a revolution in freshwater generation, because it cut energy use and changed the way we look at a very well-known application,” says Alex Jönsson, Alfa Laval’s Regional Marketing Manager responsible for the product launch. “But innovation is one side of the Alfa Laval coin, and continuous development is the other. AQUA Blue takes this pioneering technology and builds on its already substantial advantages.”
The 3-in-1 AQUA technology
The foundation of the AQUA technology, and therefore of AQUA Blue, is a unique type of titanium plate. Though plate-based freshwater generators have existed for half a century, the plates themselves have always been a modification of heat exchanger designs. Alfa Laval’s AQUA plate was the first to be specifically designed for desalination work.
The AQUA plate has a 3-in-1 construction, which means that evaporation, separation and condensation all occur within the same plate pack. First, feed water passes through the lower section, where it is evaporated in a vacuum. As the vapour rises, it then passes through the separator section, with brine falling back into the sump at the bottom of the freshwater generator. Only the clean vapour reaches the top section, where it is condensed into high-quality fresh water.
Remarkably low energy consumption
“The simplicity of the AQUA concept is surprising, considering what it can achieve,” says Jönsson. “With one plate pack instead of two, the freshwater generator needs just half the seawater flow. So only half the pumping capacity has to be installed, which means only half the electrical energy for running the pumps.”
In the new AQUA Blue, the focus on energy efficiency is also seen in the use of an IE3 motor. “Energy efficiency is even more relevant today than it was when the original AQUA was launched,” says Jönsson. “So for AQUA Blue, Alfa Laval has chosen not just an energy-efficient motor, but the most energy-efficient motor type available.”
Full peace of mind for the operator
Besides minimizing energy consumption, the AQUA technology keeps scaling to a minimum and provides consistently high-quality fresh water. To ensure still more uniform results, the flow of seawater through AQUA Blue is regulated.
“AQUA Blue operators can be sure of 2 ppm maximum salinity in all conditions, and the seawater regulation will also contribute to faster start-up times,” says Jönsson. “In fact, AQUA Blue gives operators more peace of mind at start-up and beyond, thanks to expanded instrumentation that gives them a better overview of what’s happening inside.”
From easy installation to a lifetime of service
For operators and shipbuilders alike, there are advantages in the physical construction of AQUA Blue, whose plate pack slides open for easy inspection and maintenance. Because the AQUA technology maintains the vacuum within the plate pack, there is no outer shell to be opened – and no service area needed beyond the frame.
“The AQUA concept has always had advantages for installation and maintenance, and we’ve added new features to AQUA Blue that provide further ease and flexibility,” Jönsson says. “Between the new features, the optimized process and a robust construction with duplex piping, AQUA Blue is a convenient solution that will last the vessel lifetime while asking little of the crew.”
Alfa Laval, December 2, 2013