Hypolimnetic Aeration:
the LIMNO

The LIMNO® aerates the deep, cold, oxygen-poor layers of the water body. It does not upset its thermal stability and thus avoids the mixing of the deeper layers with the warmer surface layers.

Principle of operation

Compressed air is blown into a diffuser (1) at the bottom of the LIMNO and entrains water up with it (2).

The water is reoxygenated by contact with the air bubbles (3), then returned to the bottom where it discharges through radial outlets (4).

The excess air is discharged through the vent pipe (5).

(Click to display picture)

Installation conditions:

The standard system is generally used in water bodies more than 15 m deep. For shallower reservoirs and lakes, a shorter LIMNO® may be used or, alternatively, diffuse Aeration /Destratification techniques.

Types:

There are several designs of LIMNO®, all manufactured in materials which are highly resistant to prolonged immersion in water. The largest model, 10 m long and 5 m in diameter is constructed of a flexible fabric and oxygenerated the hypolimnion to a distance of more than 300 m from the point of installation. The smallest model, in polyester, provides aeration at different flow rates.

Air supply:

Clean air (oil residual level: 0,005 ppm) is delivered by an electrically powered air compressor in an outdoor sound-proofed chamber. Where necessary, completely oil free or oxygen enriched air can be supplied.

Operation: During the deep layer oxygen deficit period usually April through October.

Maintenance: An annual visit to replace the filters and change the compressor oil.