This innovative solution involves the shrinking of a steam turbine originally designed to generate electricity. It’s also the perfect example of what GE calls the GE Store, the idea that sharing ideas across businesses can quickly lead to breakthroughs.
If successful, the system could reduce the cost of water desalination by as much as 20 percent. That would begin to break down the cost barrier that has prevented more desalination systems from being built.
The mini desalination system combines 3D printing with GE’s deep reservoir of knowledge of turbo-machinery and fluid dynamics. GE scientists Doug Hofer and Vitali Lissianski used them to shrink a power generation steam turbine that would normally barely fit inside a school gym.
Not too long ago, Lissianski, a chemical engineer in the Energy Systems Lab at GE Global Research, was chatting with his lab manager about new ideas for water desalination. This type of “small talk” happens thousand times a day at the GRC.
Their lab tackles a lot of technical challenges coming from GE’s industrial businesses including Power and Water, Oil and Gas, Aviation and Transportation, and they quickly hit on a possible solution.
It led them to Hofer. As a senior principal engineer for aero systems at GRC and a steam turbine specialist, he was part of another team of GE researchers working on a project for Oil and Gas to improve small scale liquefied natural gas (LNG) production. A key part of the project focused on using 3D printing to miniaturize the turbo expander modeled after a GE steam turbine. (A turbo-expander is a machine that expands pressurized gas so that it could be used for work.)
Hofer was the perfect person in charge. He led the steam turbine aero team at Power and Water before coming to GRC eight years ago. Few people in the world have the kind of expertise and knowledge of steam turbine technology that Doug brings. “In traditional steam turbines, steam condenses and turns to water,” he says. “We thought maybe the same principle could be applied to water desalination.”
The only difference, Hofer explained, would be in using flows through the turbine to freeze the brine, or salt water instead of condensing the steam to water as in a steam turbine. Freezing the brine would naturally separate the salt and water by turning salt into a solid and water to ice.
Lissianski and Hofer compared notes and today they are working on a new project with the US Department of Energy to test their new water desalination concept.
The reality today is that 97.5 percent of the world’s potential clean water drinking supply essentially remains untapped, locked in salty oceans and unsuitable for human consumption. This is in the face of growing global water shortage. According to the United Nations, water scarcity impacts 1.2 billion people, or one fifth of the world’s population.
Not even the United States has been spared. California, which has one of the country’s longest coastlines bordering the ocean, has been suffering through a severe water shortage crisis.
Technology inspired by a miniaturized steam turbine could help change all that. And there’s no reason to believe that it can’t. Advances in miniaturization have proven to have great impact time and time again.
For example, the application of Moore’s Law in the semiconductor world has shrunk the size of computer chips to enable mobile phones that pack more computing power than a roomful of mainframe supercomputers that were state-of-the-art just a few decades ago.
In ultrasound, miniaturization technologies have shrunk consoles to the size of a phone screen and can fit neatly into a doctor’s coat pocket. Doctors today can deliver high quality care in regions where access was previously limited or non-existent.
And steam turbines? They already have proven to be one of the key innovations that spread electricity to virtually every home and business. Miniaturized, they just might hold the key to spreading water desalination around the world.
Top image: Doug Hofer, a GE steam turbine specialist, and Vitali Lissianski, a chemical engineer in GE's Energy Systems Lab, holding the mini-turbine in front of an actual size power generation steam turbine. Image credit: GE Reports