Method for removal of fat, oil and grease from laundry wash water
AssigneeUnitog Rental Services, Inc.
InventorStephen M. Montgomery
Life of this patent
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Abstract
Method and apparatus for removing impurities from a laundry wash effluent including the steps and means therefor of acidifying the solution, infusing a gas into the solution and coalescing the released contaminant droplets by means of baffle plates into droplets sufficient to achieve buoyany with respect to the solution. The resulting top layer of buoyant droplets is skimmed from the solution and the remaining solution is adjusted to a neutral pH for discharge.
Claims11
A method for removing impurities, including oil and grease droplets, associated with a pH activated surfactant in an aqueous solution comprising the steps of:
- deactivating the surfactant in the solution to release the impurities from association with the surfactant;
- infusing a gas into the solution;
- coalescing the oil and grease droplets of the released impurities and the gas to achieve droplet buoyancy with respect to the solution, said droplets then forming a layer atop said solution;
- removing the layer from said solution;
- and
- adjusting the pH of the solution to a relatively neutral pH for sewer discharge of the solution.
The method as recited in claim 3, further comprising the step of transferring heat from the solution to a second solution prior to acidifying the solution.
A method for removing impurities, including oil and grease droplets, associated with an alkaline pH active amine surfactant in a spent aqueous wash solution comprising the steps of:
- transferring heat from the spent wash solution to a second solution;
- injecting acid into the solution in response to the pH of the solution, the resulting acidic solution pH thus deactivating the surfactant and releasing the impurities from association with the surfactant;
- infusing a gas into the solution through a plurality of inlets such that the gas bubbles rise through the solution and contact released oil and grease droplets;
- coalescing the oil and grease droplets of the released impurities and the gas bubbles to achieve droplet buoyancy with respect to the solution, said droplets then forming a layer atop said solution;
- removing the oil and grease layer from said solution;
- and
- adjusting the pH of the solution to a relatively neutral pH by the addition of a base to permit sewer discharge of the solution.
Dependencies are inferred from the claim text.