The EGGER IRIS control valve decreases the power consumption and energy costs of regulation in aeration tanks in sewage treatment plants with efficient control valve technology.


The possibilities of energy costs saving by using control valves are composed of 2 actions:

1) Energy costs saving by optimized flow construction

Mounting parts which are fixed and reduce cross section area as well as inaccurate regulation behavior causes unnecessary pressure losses and energy costs. Our IRIS control valve reduces these to a minimum by a full free passage and low turbulence. Due to the optimal form of the characteristic curve, power saving and precise regulation (even with large openings) is possible.

2) Energy costs saving by improvement of the plant characteristics

Application report about EGGER IRIS  control valve:

Optimization of the air supply control for an aeration tank in a German sewage treatment plant.

The unsatisfactory regulation behavior of the plant could not be adequately improved in spite of exact analyses of the value characteristics of the control engineering and precise adjustment of the measuring and regulation devices.

Butterfly valve actuators were operated frequently (open/close) which lead to frequent valve failure. The regulation of the plant was unstable and there were large deviations from the desired values up to +/-20%.

After replacement of the butterfly valves with EGGER IRIS control valves it was possible to improve considerably the characteristics of the plant. The set values were decreased from 2 mg/l to 1.5 mg/l. A substantial energy costs saving and a short amortization period for the optimization of the plant was obtained.

Even temporary variations of the oxygen content, cause unnecessary energy costs and must be reduced to a minimum. When oxygen instantaneous value is decreased by 0.5% mg/l the diagram shows an exponential decrease of
power demand by 10% for the blower or compressor. Long life span in high service frequency use due to the robust construction of the Egger Iris control valves. Compared to valves with a weaker construction, life cycle costs are reduced. For example, the first delivered EGGER IRIS control valves were installed 25 years ago in the sewage treatment plant of Heidelberg and are all still working.