Venturi Eductors

Venturi eductors convert the output of a blower into a ‘vacuum’ that can be used to entrain and feed powders, pellets, and bulk solids into a pneumatic conveying system. Because they have no moving parts, they can operate entirely maintenance free.

As venturi eductors have no moving parts, this allows for maintenance-free feeding of bulk solids. In applications involving fine, abrasive, or irregularly-shaped products, this is an enormous advantage. Replacement of rotary airlocks with venturi eductors makes for simpler, more reliable conveying systems. Designing with eductors from the beginning ensures the most reliable product feeding available.

How Are They Used?

The eductor acts to compress the air/solids mixture to a pressure adequate to overcome losses in the downstream convey line. The eductor has three connections: 

  • motive air 
  • suction or product inlet 
  • discharge

Fox venturi eductors are used to feed bulk solids, such as powders, pellets, flakes, and particulates, into positive, dilute-phase conveying systems. They are commonly used in place of rotary valves where airlocks simply cannot perform adequately.

Fox eductors create suction at the product inlet, they enable dust-free material conveying systems. They are commonly installed beneath: 

  • bag-houses / dust collectors 
  • volumetric and loss-in-weight screw feeders 
  • screener / classifier outlets 
  • mixers, grinders and mills 
  • bins, silos and bulk bag unloaders


Eductors are frequently installed beneath dust collectors, often replacing screw conveyors which collect dust from multiple outlets. Screw conveyors are primary sources of fugitive dust, often need repair, and require that all modules of a bag-house are shutdown if one outlet is clogged or needs repair. Multiple eductors enable all outlets to operate while one is accessed for maintenance. 

Retrofitting existing systems with Fox eductors can result in very significant improvements. These may include: 

  • Eliminate airlock wear 
  • Reduce product damage / degradation 
  • Avoiding dust emissions and leakage 
  • Facilitate clean-outs if cross-contamination is critical 
  • Reclaim otherwise discarded product.