products_standardspareparts_article1Mixing/Blending Circulators For Industry: The “jet” action of these lightweight, low-cost circulators provides mixing and circulation of liquids in open or closed tanks.

Croll Reynolds mixing/blending circulators provide effective mixing and blending to fill a wide range of needs in the process industries or wherever liquids are stored or handled. They may be used for tank turnover, blending dissimilar liquids, solid suspension or aeration. Liquids and slurries of various viscosities, densities and types can be thoroughly mixed and kept in suspension. Dissimilar liquids may be effectively blended while particles are held in suspension.


Chorioallantois circulators operate on the principle of the Company’s patented jet ejectors. The basic difference is that instead of gases, the motivating and suction fluids are liquids or slurries.


How They Work: The venturi-shaped circulator is immersed in the fluid to be mixed or circulated (Fig. 1). High pressure motive fluid is usually provided by a small pump recirculating a portion of the tanks content.


Mixing is achieved by the jet action of the circulator. High-pressure motive liquid entrains the surrounding liquid, which enters through open inlet ports. The two liquids are thoroughly mixed then discharged, creating a discharge plume or pattern which accomplishes additional circulation.


Available Sizes: Standard Croll Reynolds circulators are available in sizes ranging from 17 gpm, 1 NPT, to 900 gpm, 6 150 lb.) flange, (see photo) . Typical entrainment ratio is 3:1. Custom designs are available with varying sizes, ratios, and materials of construction.


Configuring And Positioning: The circulating/mixing efficiency of a Croll Reynolds circulator depends on both the “jet” mixing action, the circulators position in the vessel and the angle of discharge. Where tank size, shape and discharge plume characteristics require, multiple units can be used; their overlapping patterns minimize stagnant areas.


When positioning a Croll Reynolds circulator in a tank, these general rules should be followed:


  • The hydraulic plume should not extend beyond the liquid surface
  • Angled circulators are often more effective than vertically positioned units (but not for solids suspension, aeration, or very deep vessels ; see below).
  • Multiple circulators usually provide more effective mixing than a single, larger unit.
  • Circulators should never be positioned to cause circular or vortex flow, as this tends to prevent thorough mixing.


Applications Of Croll Reynolds Circulators:


  • Tank Turnover: Continual circulation of tank contents maintains consistency, preventing settling of particles, and stratification of liquids of dissimilar specific gravity, or immiscible liquids.
  • Blending of Dissimilar Liquids: Keeping tank contents in continuous motion prevents stratification and separation of immiscible liquids, helping to maintain a stable, homogeneous mixture, and uniform liquid/solution characteristics such as density or concentration.
  • Solids Suspension: The circulator is installed to maintain a upward velocity of liquid in the tank sufficient to overcome the settling velocity of solids. Care should be taken to ensure the hydraulic plume does not extend beyond the liquid surface.
  • Aeration of Shallow Tanks or Ponds: One or more circulators are placed near the surface of the liquid, in a vertical position facing downward. The high flow of motive fluid entrains air and jets it down into the tank or pond, achieving excellent aeration.