• Available in turbine, hydrofoil or picket fence design
  • Supplied with variable speed drives
  • Impellers and shafts in stainless steel
  • Heavy-duty gear reducers for long service life


Flocculation is a process that consists of gently mixing the water/wastewater in order to agglomerate and form larger composite particles or flocs. The efficiency of removal of solid and other impurities by the solid-liquid separation process that follows flocculation process, increases if the raw water is properly flocculated. A well-designed flocculator provides good flocculation and years of trouble-free operation.

Napier Reid is a leading designer and manufacturer of high quality, well-designed vertical shaft flocculators. Unlike some manufacturers who try to adjust their standard product to suit your process requirement, Napier-Reid specifically designs and manufactures all the key components including the type and blade diameter of impeller to optimize the flocculation process for which they are intended.


Component’s Features

Electric Motor

  • High efficiency electric motors from partner manufacturers
  • TEFC AC electric motors are of all cast iron body construction, are continuous and inverter duty rated, have minimum service factor of 1.15, are chemical resistant, and come with class ‘F’ insulation.
  • Capable of running at variable speed to attain range of velocity gradient (G) value


Gear Reducer

  • High efficiency, heavy duty helical / bevel gear reducers built and rated in accordance with current international gear manufacturing standards
  • Robust in design and built with high quality components
  • Drive housing fabricated in high quality cast iron
  • Oversized bearings for severe duty application and long bearing life
  • All bearing are antifriction type, ball or roller bearings with minimum L-10 life of 100,000 hours
  • Drywell feature provided if required
  • Noise level is within 85 dBA at full operating load
  • Drive unit is provided with mounting base plate


  • Shaft designed to handle the loads occurring including the transmission of torque, thrust, hydraulic forces, and overhung moment
  • Maximum stress in any component does not exceed 9,000 psi under maximum operating load
  • Hollow shaft design of high strength but comparatively less weight compared to equivalent solid shafts
  • Hollow shaft results in less deflection of shaft and less thrust transmitted to drive bearings increasing its bearing life significantly
  • Shaft-impeller system designed to operate at minimum 25% away from its first lateral critical speed
  • 304 SS / 316 SS standard material of construction


  • Large diameter axial flow impellers provide bulk fluid motion and dissipate the imported horsepower over a wide area
  • Wide range of impeller blades: flat blade turbine; constant angle of attack (32° and 45° pitched blade turbine) or variable angle of attack (3-blade or 4-blade hydrofoil) to meet the process requirements
  • Flocculator designed for a range of G-values with variable-speed drive
  • Where required, impellers blades provided with proplets to reduce shear
  • Adjustable impeller blade height
  • 304 SS / 316 SS standard material of construction