Water treatment technology firm Fortrans says it has developed a new way to produce low-cost deaerated, or de-oxygenated, water, which companies can use in lieu of chemical processes at about half the cost of membrane filter or vacuum pump systems.
When oxygen combines with metals or salts in water, it will affect the taste, odor and shelf life of packaged food and beverages.
In hot water or steam production systems, oxygen reacts with metals in the heated environment, which causes heat exchangers and piping to corrode. Because of this hot water system owners may have to install expensive oxygen scavengers to displace the dissolved gas and prevent corrosion, Fortrans says.
Using a mechanical deaerator for oxygen removal can be more practical and economical in hot water and steam systems compared to using oxygen scavengers and other chemicals. Breweries use de-aerated water to ensure shelf life and taste in their canned and bottled products. Food plants that package fresh vegetables may use de-aerated water to improve taste, color, and extend shelf life.
One method currently used to produce deaerated water uses membrane filter systems. Systems are sized and priced at various capacities in terms of gallons per minute. These systems require a 7.5 HP or larger vacuum pump.
Fortrans says the downside to membrane filters is that they require regular maintenance and or replacement, depending on the purity of the water source, in addition to being labor intensive to clean and sanitize in food or beverage plants.
Other more mechanized systems use boiling water and vacuum pumps to remove the oxygen from the water. These types of system have high-energy consumption and are priced per GPM of deaerated water required. These types of systems are common in coal and gas power plants where heat transfer efficiencies need to be optimized.
Fortrans says its new technology produces low cost deaerated water by integrating its Dif-Jet gas injector into batch production of deaerated water in storage tanks. The Di-Jet gas injector is used to inject and mix nitrogen gas into a pressurized water pipe and then discharged into and circulated in a tank of water. The nitrogen, being highly soluble in water, will force the oxygen out of the water without requiring a vacuum pump, heat or other device. The oxygen is vented out of the top of the tank automatically.
Fortrans conducted testing using a 500 gallon closed head polyethylene tank with a single Dif-jet gas injector. A ¾ HP circulation pump is connected to the injector piping that is connected to the intake and discharge fittings on the tank. The injector is connected to a regulator installed on a standard 300 cubic foot cylinder of nitrogen gas.