Understanding Industrial Agitator Types to Better Meet Process Needs

In industrial mixing, there is no one-size-fits-all solution. Each process, fluid, and tank geometry bring its own set of challenges. Understanding the different types of agitators - and the logic behind their design - enables better performance, equipment reliability, and product consistency.

In this edition, we provide a technical overview of five major families of industrial agitators. We’ll explore how each one works, where it fits best, and what to consider when selecting the right design for your application.

Vertical Agitators for Open Tanks: HELISEM & HM Series

The HELISEM range is well-suited for small to medium open tanks.
These modular mixers can be equipped with marine propellers, pitched blade turbines, flat blades, and high efficiency axial flow propellers depending on whether the goal is homogenization, suspension, or simple motion.
The HM Series has been designed for water & wastewater treatment applications with over 5,000 units installed worldwide. Every unit can be fully customized according to customer specifications.

Did you know? In viscous mixing (Re <10^4), double or triple impellers are often required to avoid dead zones.

Yellow motor mounted on a grated walkway above dark water in an industrial setting

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Helisem Top-Entry Mixers

Increase the efficiency of your processes with HELISEM vertical agitators. A complete range for your gentle, medium, or vigorous agitation needs.

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HM Series Top-Entry Mixer

The Milton Roy Mixing HM top-entry mixer is a configured industrial agitator for water treatment and chemical processing that's designed for robust environments

Side-Entry Mixers for Large Storage Tank

Side-entry mixers provide a horizontal swirl that ensures full-volume circulation with limited energy input – as in oil storage or chemical processing.

Side-entry mixers generate horizontal swirling motion, which promotes full-tank circulation with relatively low energy input. They are commonly used to prevent sedimentation in crude oil tanks.

Maintenance can also be optimized with shut-off devices or cartridge seals that allow seal replacement without draining the tank.

Did you know? Side-entry mixers are often angled slightly (typically 10°-15°) to optimize bottom sweep and ensure uniform movement throughout the tank.

Did you know? In side-entry agitation, the number and position of mixers can drastically impact circulation efficiency-especially in flat-bottom tanks, where poor placement can create stagnation zones regardless of mixer power.

Side-entry mixers with blue motor, yellow guard, and metal impeller.

SRMix: Compact Side-Entry Mixers for General Industry

SRMix belongs to the family of side-entry mixers but responds to a different set of constraints from those seen above. It is specifically designed for installations with limited space, or thin-walled tanks, where standard equipment would be too bulky or invasive.

Its compact architecture allows wall mounting at the base of the tank, without the need for structural reinforcements. The flow is primarily axial, promoting overall fluid turnover while limiting dead zones, making it suitable for basic homogenization or prevention of phase separation.

SRMix

Ultra-compact side-entry mixers. Ideal for thin-walled and confined spaces.

Simulation of fluid flow patterns in a cylindrical tank with two side-mounted mixers.

Customized Mixers (ROBIN) - Tailored Designs for Complex Needs

Some mixing systems simply cannot be standardized. Whether it’s extreme temperatures, high pressure, specific materials, or unusual installation constraints, customized agitators are sometimes the only viable options.

The ROBIN Series is built entirely to specification. These mixers can be installed from the top, side or bottom, and are tailored to the customer’s process and mechanical requirements - whether that includes pressure, vacuum resistance or ATEX environments.

Each project can begin with a deep technical analysis using tools such as Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA), along with real-world performance testing & lab testing.

Did you know? Our Robin customized agitators can reach shaft lengths over 30 meters (100 ft) or more - without compromising precision or mechanical stability.

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Heavy-Duty Mixers | ROBIN Agitators

ROBIN industrial agitators are custom-made and perfectly attuned to meet the characteristics of complex processes in extreme conditions.

Floating Mixer: For Basins, Lagoons, and Open Ponds

Open air basins or lagoons present unique challenges: fluctuating liquid levels, limited anchoring points, and exposure to the elements. They are difficult to equip with fixed systems.

The HELIFLOAT is a floating axial-flow agitator that adjusts to the fluid level and follows the fluid surface. Suspended beneath the float, the impeller produces vertical circulation throughout the basin, even at significant depths.

This solution is ideal for wastewater treatment, settling ponds, and aerated lagoons - where continuous fluid motion prevents sludge buildup and supports aerobic bacterial activity.

Did you know? The float acts not just as a support, but also as a stabilizer against vibrations and wave movement - critical in shallow lagoons.

The HELIFLOAT is a floating axial-flow agitator

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HELIFLOAT Floating Mixer

HELIFLOAT floating agitators/mixers are an economical, energy efficient investment, producing high-displaced volumes for water treatment basins and tanks.

Final thoughts: Matching Technology to Process Context

There is no universal agitator design ; each must be adapted to the fluid properties, tank shape, mixing objectives, and site conditions. From floating sixers for lagoons to engineered systems for complex reactions, effective mixing starts with a solid understanding of physical principles.

By mastering these variables, our engineers can design systems that are not only effective, but also durable, energy-efficient, and tailored to your long-term industrial needs.