Positioning of eductor nozzles
Eductors will produce a plume of moving fluid. These will tend to have a length equal to 4.3 metres per 1 bar of pressure drop across the eductor. The plume will have a 'spray angle' of around 12 degrees and so forms a narrow cone of moving fluid. Ideally edcutors should be positioned so that these plumes hit the opposite wall of the tank and so further dissipate as they do so.
Little mixing will occur below the eductors so they should be positioned low in the tank and angled upwards. But if no sedimentation is to be tolerated then a set of eductors can be angled downwards to sweep along the floor of the tank. In such cases the 4.3m/1 bar plume reach should be halved to 2.15m/ bar.
Ideally one should aim to cover as much of the tank as possible with the estimated moving plumes. In this way an even mixing/agitation will occur with no 'blind' spots that will allow for sedimentation to occur in parts of the tank. This will normally necessitate multiple eductors per tank.
It is very common to attach eductors to pipework with adjustable nozzle holders that allow for the eductor to be moved 45 degrees in two dimensions. This means that the final plume directions can be adjusted in the field for optimum coverage.
We offer two ranges of eductors. For metal nozzles the Turbomix eductors offered by SNP are made as standard in 316 stainless, cast iron or brass but in principle can be made in any metal desired. The Uni Eductor from Uni-Spray is made in either glass filled polypropylene or PVDF (Kynar) and form part of the Quik Fit system for pre-treatment spray tunnels. Datasheets on both ranges can be accessed by clicking on the boxes below.