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About Heron InnovatorsSAF™ Treatment Technology History and Description - In continuous development since 1975, Heron Innovators Suspended Air Flotation (SAF™) treatment technology incorporates all of the innovations and improvements made over the years, and now offers these exciting new improvements:
- Microbubble generators of much larger capacity
- Flotation equipment of radically reduced size
- Float solids dewatering which is simple and effective
Heron Innovators scientists and engineers have been involved continuously from the beginnings of development of this flotation treatment technology.
FIRST GENERATION – Micro Gas Dispersion - The Micro Gas Dispersion was invented by the late Dr. Felix Sebba in 1975. A MicroGas Dispersion is an emulsion of bubbles in water with diameters ranging from 5 – 50 micrometers. The Micro Gas Dispersion contains 40% – 65% of air by volume, and is stabilized by the addition of a surfactant which coats each bubble and prevents the coalescence of the bubbles. Daniel C. McLean, an engineering professor (now retired), worked with Dr. Sebba on the original development and remains a consultant to Heron Innovators Inc. The Micro Gas Dispersion generator technology of 1975 was able to produce small flow rates, less than 2 liters per minute, suitable for experimental and development purposes but too small for industrial applications. Heron Innovators refers to this Micro Gas Dispersion as MicroFroth™.
SECOND GENERATION – Superfroth - Professor McLean, and the engineering and production team now with Heron Innovators, further developed the Micro Gas Dispersion technology under the trade name Superfroth, to the point where flow rates up to approximately 12 gallons per minute of microbubble emulsion could be sustained. A short-term flotation demonstration on activated sludge mixed liquor was conducted in late 1995 at the Red Bluff, California municipal wastewater treatment plant. The microbubble flotation cells at that time were of conventional design, similar to the circular and rectangular flotation cells still used in the Dissolved Air Flotation (DAF) process.
THIRD GENERATION – SAF™ - SAF™ technology by Heron Innovators is the successor to the Superfroth technology. SAF™ has incorporated all past developments, and has taken flotation treatment to a new level, rendering this technology suitable for all municipal and industrial wastewater treatment and product recovery operations, from the very smallest to the very largest. SAF™ with its suspended air emulsion generated in Heron Innovators proprietary design microbubble generators, effectively replaces DAF in all flotation treatment applications. The SAF™ flotation treatment process works so well because the coagulating and flocculating chemicals impart to the floc particles in the wastewater an electrical charge which is opposite to the electrical charge of the surfactant forming the film on the MicroFroth™ microbubbles. The microbubbles tightly adhere to the floc particles by electrostatic attraction and form stable float solids which rises extremely quickly to the surface and are skimmed off.
Heron Innovators has made three exciting improvements to the technology, while still retaining all of the unique advantages of this remarkable treatment process.
- Capacity increase. The maximum capacity of Heron’s SAF™ microbubble generators has been increased by an order of magnitude. The largest unit in production, the Model F-400, is rated for continuous production of 100 gallons per minute of microbubble emulsion. This removes any limitation on the maximum flow of water able to be treated.
- Footprint decrease. The size of Heron’s ClearFloater™ flotation tanks has been reduced by an order of magnitude, compared with DAF and former microbubble flotation designs. Heron’s ClearFloater™ flotation tanks operate at a design hydraulic loading rate of 10 gallons per minute per square foot of flotation area and a solids flux of 10 lb. per hour per square foot, both 10 times that of a DAF unit. This reduces the cost and especially the footprint of a SAF™ treatment system.
- Solids dewatering. The solids floated out of the wastewater in a ClearFloater™ flotation cell are stable and gelatinous in nature, because they contain entrained air bubbles. These stable solids can be dewatered by simple gravity drainage on a slowly-moving conveyor or internally-fed mesh cylinder. Heron’s ClearFloater™ flotation cells are supplied with these simple, inexpensive, and easily maintained dewatering devices where solids dewatering is desired. NO OTHER FLOTATION TECHNOLOGY can offer solids dewatering as part of the flotation process.
DON’T BE FOOLED BY IMITATORS – Insist on SAF™ by Heron Innovators!
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