Quadair IGF

The Quadair IGF is designed to break emulsions by means of flotation and purifies wastewater using a multi-compartment system that conserves space and keeps costs down.
Cylindrical Configuration Four Cells

Over and under Welded Internal Baffles

Single, Dual or Multiple Eductors per Cell with Needle Valve

Dual Reject Troughs with Three Skimming Options
Inlet and Effluent Sample Points

Internal and External Painting System

Dual Recirculation Pumps with Associated Valves and Piping

Controlled and Instrumented per Specifications
The ESI Quadair IGF is divided into six compartments, an inlet distribution compartment (1), four flotation compartments (or cells) (2), (3), (4), (5) and a clean water outlet compartment (6). Each compartment is separated by a pair of over/under baffle plates (7) which prevent short circuiting.

A centrifugal pump (8) recirculates the clean water through a header to an eductor (9) in each flotation cell. Recirculation rate is 50%-125% of the total throughput. The ESI’s Quadair IGF can be equipped with one (1) recirculation pump or with an additional standby pump.

A gas blanket (10) (1-2 oz/sq2) is maintained above the water level to help saturate the liquid. As the recycled water passes through the venturi-type eductor, it creates a slight vacuum pulling gas into the eductor nozzle. Gas flows through a ½” line into a stainless needle valve controlling the amount of gas entering the flotation cell. By controlling the gas induced, the proper bubble size and pattern for efficient lifting of suspended solids and oils is achieved.

Oil and suspended solids create a froth on the liquid surface where they are continuously removed by means of adjustable v-notch weirs, rotating wiper blades or rotating pipe skimmers. The average skim rate ranges from 1-3% of the total liquid throughput and the residence time is approximately 5 minutes. All Quadair IGF's meet API's RP 14C and can usually achieve 90-97% efficiency due to the combined features of the baffle configuration, recirculation rate, eductor design and gas volume adjustment.

Quadair Flotation Unit

The ESI Quadair Induced Gas Flotation Unit is designed and engineered to remove oil emulsions, suspended solids and organic materials from wastewater.

The Quadair requires minimal operating power, uses less floor space and has low installation and maintenance costs. Standard Quadair units are available (see sizing table) & ESI can design special models to meet specific needs.

The ESI Quadair Induced Gas Flotation Unit is designed and engineered to remove oil emulsions, suspended solids and organic materials from wastewater.

ESI Quad-Induced IGF Model Number Selection Chart


Model Number Flowrate GPM Flowrate BWPD 3/60/440 Motor HP Approximate Skid Size L x W x H Approximate Weight Dry (LBS) Approximate Weight Wet (LBS)
QH-5 146 5,000 5 15'-0" x 6'-0" x 6'-9" 8,000 15,000
QH-10 292 10,000 7.5 15'-6" x 6'-9" x 7'-0" 10,000 24,000
QH-15 438 15,000 15 20'-0" x 8'-6" x 8'-0" 12,000 35,000
QH-20 593 20,000 20 20'-6" x 9'-0" x 9'-0" 15,000 42,000
QH-25 729 25,000 25 20'-6" x 10'-0" x 9'-9" 18,000 50,000
QH-30 875 30,000 25 21'-6" x 10'-9" x 10'-0" 25,000 78,000
QH-40 1,167 40,000 35 24'-0" x 13'-6" x 10'-0" 35,000 125,000
QH-50 1,458 50,000 50 23'-0" x 14'-0" x 12'-0" 40,000 140,000
QH-75 2,188 75,000 75 25'-0" x 16'-0" x 13'-0" 45,000 160,000
QH-100 2,917 100,000 100 33'-0" x 18'-0" x 14'-0" 50,000 180,000