Spray nozzles


Sizing Eductor Nozzles

Eductor nozzles are positioned under the surface of fluid in a tank in order to keep it in motion. The liquid in the tank is circulated through the eductors so that it is "turned" over a period of time to ensure that sedimentation or liquid separation does not occur. Eductors have gaps at the back of the nozzle casing that allows surrounding fluid to be drawn in an moved in addition to fluid being pumped through the nozzle. This means that about 5 times the pumped fluid is actually moved by an educator.

Like all nozzleseductors have a flow rate that is proportional to the pressure drop across the nozzle. So it is a simple matter to consult the flow rate vs pressure charts for eductor nozzles to determine how quickly they will turn the fluid in the tank. One "turn" is defined as moving the whole volume of fluid contained within the tank. So, given that eductors move 5 times their motive flow rate, eductors should be sized to turn 1/5th of the fluid in the appropriate time.

The turn time will vary greatly depending on the application but typically 

A general circulation of fluid with no solids only 1-3 turns per hour will be required.
For mixing fluids to keep solids suspended between 5-10 turns per hour are required.
For plating and rinsing tanks between 10-25 turns per hour are required.
For blending applications anything between 20-120 runs per hour 

These are general rules of thumb and some variations outside these guides may occur fro specific applications.
Eductor-basic-opperating-principles

 

 

Adjustable holders

It is very common to attach eductors to pipe work 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. 

Eductor models

We offer two ranges of eductors. For metal nozzles the Turbomix eductors from Bete Fog Nozzle 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.



Uni Eductor Turbomix eductor mixing nozzle

 

Fluid Agitation Engineering Considerations