EVERETT — A new twist on an old technology is making a big difference in cleaning seawater from warships at Naval Station Everett.
The base is helping to develop a new filtration system for refueling the giant vessels.
Only two devices have been built, and both are on the base.
The machine cleans seawater that has been in the ships’ gas tanks. In initial testing, the Navy reported it has saved a significant amount of time and money.
The Everett base has been collaborating with two other Navy departments. One of them, the Expeditionary Warfare Center, designed the contraption, said Cmdr. Brad Coleman, Naval Station Everett’s public works officer.
“We are operating it and finding best practices, and helping establish a quote-unquote owner’s manual,” he said. “So if they make any more, they would use our information to instruct those next people.”
As gas burns at sea, it’s replaced with ocean water to keep the ship balanced. The mixture is later drained from its fuel tanks.
The new equipment uses cyclone technology. It’s not necessarily a new idea. It can be found in Dyson-brand vacuum cleaners, for example.
The innovation is that it’s being geared toward this type of work, Coleman said.
The new machine is portable and housed in a shipping container.
It can process up to 250,000 gallons of liquid in eight to 16 hours. Before, the same amount of work could take a couple of weeks.
The device saves about $65,000 each time it is used, Coleman said.
The equipment separates the gas from water in several steps.
First, the water and gas are pumped into its cone-shaped chamber. The contents spin until the two liquids are separated.
Water is more dense, so it’s pulled to the outside as the oil collects in the center. The process also removes metals, such as zinc and alumina.
The water is tested to make sure it contains less than 4 milligrams per liter of zinc, as required by the city and state. It then goes to the city’s sewer system.
The remaining fuel moves to a treatment facility on base that is used to complete the entire filtration process. It didn’t work as well because that machinery wasn’t equipped to handle such diluted oils, Coleman said.
After, the fuel is taken to a refinery and recycled.
The base received the new system in late 2017, said Ray Smalling, Naval Station Everett’s public works utility energy manager. He’s been one of the project leaders.
After that they spent several months getting the right permits. They started using the device earlier this year.
Smalling wants to thank the city of Everett for its help.
“They worked with us, they were timely in their reviews and understood how this was going to make things better,” he said.