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.
Croll-Reynolds 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 tank’s 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.
CONFIGURATING AND POSITIONING
The circulating/mixing efficiency of a Croll-Reynolds circulator depends on both the "jet" mixing action, the
circulator’s 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 dissimlar 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..
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