The advantages of the return nozzles are their low operating costs (as no atomizing air is required), their large control ratio of at least 10:1 and their almost constant droplet size over the entire control range.
With the new generation of RS II-3 nozzles, the droplet size D32 at 507 psi,g could be reduced to 85 – 130 µm over the operating points of the complete series. Several case studies for gas cooling towers have shown that it is possible to reduce the evaporation distance by an average of 30%. With the significantly finer droplets, the required evaporation distance can even be reduced by up to 50% compared to conventional spillback nozzles. Thanks to the optimized evaporation path, the spillback system can be used in more applications as an alternative to the twin-fluid system.
In addition, the revision of the Lechler return nozzles resulted in further design advantages such as flow-optimized spray angles, less individual parts and the possibility of assembly with standard tools.
The RS II-3 (290 series) comprises a total of seven nozzles in the volume flow range between 0.16 – 7.4 gal/min and will completely replace the previous RS 3 nozzles (260 series).