The top inline mixers for flocculation in water treatment are AquaShear, FRC, Statiflo, Westfall, Kenics, Koflo, and Komax, each matched to a different stage of the coagulation and flocculation process.
Flocculation in water treatment lives or dies on how the chemical hits the water. Add a coagulant like alum or ferric chloride and it starts reacting in under a second. If the mixer does not spread it fast and evenly, some water gets overdosed and some gets almost none. That wastes chemical and leaves weak flocs that will not settle.
Two mixing jobs happen here, and they pull in opposite directions. Coagulation needs a hard, fast burst of energy to scatter the coagulant before it hydrolyzes. Flocculation needs the opposite: slow, gentle motion that lets flocs grow without tearing them apart. Water treatment texts put rapid-mix velocity gradients in the hundreds per second and flocculation gradients near 20 to 75 per second. One mixer rarely does both well.
Inline mixers handle this without a motor. They pull mixing energy from the water’s own pressure drop as it passes fixed internal parts, pipe sweeps, or opposing jets. No bearings, no gearbox, no seals to grease. This guide rates seven inline mixers used for coagulation and flocculation, scored on shear control, headloss, chemical savings, maintenance, and the stage each one fits best.
Quick comparison: inline mixers for flocculation at a glance
High-shear jet and plate mixers lead the coagulant flash-mix and polymer activation stage, while low-shear vane, helical, and pipe-sweep mixers handle gentle floc growth.
| Mixer | Type | Best-fit stage | Pros | Cons |
|---|---|---|---|---|
| AquaShear | Hydraulic opposing-jet, motionless | Coagulant flash-mix, polymer activation | 99% polymer activation in 1 sec (lab); 52% chemical cut; 15-min quarterly service | High-energy design, not gentle floc growth |
| FRC F-Series | Inline pipe flocculator, sweeps plus zones | Coagulation and flocculation ahead of DAF | Purpose-built flocculator; staged dosing; low-shear sweeps; air injection | Sized to a DAF; serpentine footprint |
| Statiflo | Low-shear helical, motionless | Gentle flocculant dispersion | 30+ years in water; protects floc integrity; non-ragging versions | Helical headloss can run higher; confirm US support |
| Westfall (2800/7000) | High-shear plate; two-stage plate plus vane | Rapid coagulation; full coag-floc in one spool | Compact wafer; 7000 stages both jobs; decades of service | Fixed geometry needs careful flow sizing |
| Kenics (Chemineer/NOV) | Helical KMS plus low-headloss HEV/WVM | Coagulant mixing, low-headloss floc duty | Original helical element; 1,000+ HEV installs; global support | Classic KMS higher headloss; support varies |
| Koflo | Housed Blade static elements | Coagulant and chemical dosing, pH, chlorination | NSF/ANSI 61 certified; injection ports; removable stainless elements | General-purpose; not a staged coag-floc system |
1. AquaShear: hydraulic opposing-jet mixer for coagulant and polymer dispersion
AquaShear is a motionless hydraulic mixer that collides opposing water streams into a vortex, dispersing coagulant and activating polymer in about one second with no moving parts.
Company overview
AquaShear comes from Johnson Specialty Tools in Midland, Texas. The company acquired the AquaShear technology in 2022 and has run the design in the field for more than two decades. It is a hydraulic mixer with no blades. Water enters from opposite sides of a chamber and the streams collide at a set angle, aligned to about a tenth of a degree. That collision spins up a vortex that blends chemical through the whole stream in a single pass.
The chamber has no bearings, seals, or gearbox. It runs on line pressure alone, so there is no motor to wire or maintain.
What sets it apart
The front-end numbers are the draw. In lab work the mixer reached 99% polymer activation in one second. In field trials it cut a six-hour blend down to 45 minutes and trimmed chemical use by 52%. For a plant fighting polymer or coagulant cost, that is the line item that moves. The same opposing-jet action drives complete polymer activation for coagulation and sludge conditioning.
Nozzle disks come in polyurethane, Teflon, or Delrin depending on the chemical. Bodies are carbon steel, 304 stainless, or 316 stainless for acids and caustics. Chamber sizes run from 1 inch to 14 inches. High-temperature polyurethane handles up to 250 degrees F.
Applications
Coagulant flash mixing, polymer activation, chlorine and sodium hypochlorite dispersion, soda ash and pH adjustment, and wastewater conditioning across municipal and industrial plants.
Pros
- 99% polymer activation in one second in lab testing, which cuts polymer and coagulant waste.
- No moving parts, so service runs about 15 minutes per quarter.
- Installs in under four hours on standard Victaulic or ANSI flanges.
Cons
- Its strength is high-energy rapid mixing, so it fits the coagulation and polymer-activation stage rather than the gentle floc-growth stage. Delicate downstream flocculation still needs a low-shear device or a basin.
- Published performance comes mostly from the maker’s own lab and field trials rather than third-party municipal references.
Best for
Plants that want to cut coagulant and polymer spend at the rapid-mix and makedown step, and operations that need steady dosing across variable flow without a motor to service.
Contact
Address: 11208 West County Rd. 46, Midland, TX 79707
Phone: 432-999-8325
Website: aquashearusa.com
2. FRC F-Series: inline pipe flocculator built for DAF pretreatment
The FRC F-Series is an energy-free inline pipe flocculator that stages coagulant and polymer, protects the floc with low-shear pipe sweeps, and can inject air ahead of a DAF.
Company overview
FRC Systems International, now a Sulzer company, builds the F-Series as a purpose-made flocculator, not a general chemical mixer. Wastewater runs through a climbing, serpentine pipe with injection ports along the path. Coagulant goes in first, then polymer several pipe runs later, with sampling ports so operators can tune dose as the influent shifts.
What sets it apart
FRC treats floc tube design as the whole game, since it drives how well solids separate in a dissolved air flotation (DAF) system. Instead of forcing high shear at 90-degree elbows, the F-Series uses wide-radius pipe sweeps to cut shear and protect the floc, with short reduce-and-expand mixing zones for precise chemical dispersion. Air injection ports can entrain microbubbles into the floc before the DAF. Units run up to 4,000 GPM in SS304, SS316, HDPE, or PVC.
Applications
Staged coagulation and flocculation ahead of DAF, pH correction, coagulant and polymer dosing, and whitewater or air injection for flotation.
Pros
- Purpose-built for coagulation and flocculation, not a repurposed mixer.
- Low-shear pipe sweeps protect floc structure for better DAF capture.
- Staged dosing and sampling ports, plus optional air injection.
Cons
- Engineered around a DAF, so it is a sized system rather than a drop-in inline mixer for any injection point.
- The climbing serpentine pipe takes more space than a single wafer mixer.
Best for
Industrial and food-processing plants running DAF that want coagulation and flocculation handled inline, with air injection built into the same system.
Contact
Website: frcsystems.com
3. Statiflo Motionless Mixer: low-shear specialist for floc protection
Statiflo builds low-shear helical motionless mixers with a long municipal water record, made to disperse flocculant fast while keeping shear low enough to protect floc integrity.
Company overview
Statiflo has supplied motionless mixers to the water and wastewater industry for over 30 years, including some of the world’s largest desalination plants. Its helical elements divide and recombine the flow to spread chemical evenly. The pitch here is control: enough mixing to distribute coagulant or flocculant, not so much that it shreds the flocs.
What sets it apart
Statiflo backs its water mixers with chemical injection lances that drive the additive into the core of the mixer. Sampling sits close to the injection point, so operators can trim dose with little lag. For messy feeds, its Non-Ragging Static Mixer resists the rags and stringy solids that clog classic elements. It also makes a short-length DesalMixer for turbulent dosing in desalination pre- and post-treatment.
Applications
Coagulant and flocculant mixing, pH adjustment, disinfection, gas dispersion, recarbonation, and both potable and wastewater treatment.
Pros
- Long, verifiable municipal and desalination record worldwide.
- Low-shear helical design suited to flocculant dispersion without floc damage.
- Non-ragging versions for solids-heavy wastewater.
Cons
- Helical elements can carry more headloss than vane or plate designs unless specified carefully.
- UK-founded supplier, so US buyers should confirm lead times and local support.
Best for
Drinking-water and desalination plants that need gentle, even flocculant dispersion with a deep reference list behind it.
Contact
Website: statiflo.com
4. Westfall Static Mixer: high-shear plate plus a two-stage coag-floc option
Westfall builds the high-shear Model 2800 plate mixer for coagulation and the Model 7000, which pairs the 2800 with a low-headloss 3050 vane to run coagulation and flocculation in one spool.
Company overview
Westfall Manufacturing builds static mixers in Bristol, Rhode Island. Its founder, Robert Glanville, holds the 1998 patent on the plate-type static mixer. The Model 2800 is a compact wafer plate mixer that drops into pipelines from half an inch to 120 inches and takes up to six additives at once. The Model 7000 combines the 2800 with the low-headloss 3050 vane mixer for the full coagulation-to-flocculation sequence.
What sets it apart
The 2800 uses a computer-designed orifice with bent tabs to create high-shear vortex shedding, which scatters coagulant fast in a short lay length. In the 7000, the 3050 then takes over with slow, low-energy mixing that lets flocs bridge and grow, replacing long serpentine pipe. Westfall lists K-values on the 3050 from 0.58 to 1.64, which it says causes two to four times less headloss than other mixers, and rates its static mixers for up to 40 years of service.
Applications
Rapid coagulation, flocculation, chlorination and disinfection, pH control, and polymer or polyelectrolyte dosing across municipal and industrial water.
Pros
- Compact high-shear wafer for tight retrofits, with drop-in installation.
- The 7000 runs coagulation and flocculation as two matched stages in one spool.
- Low-headloss 3050 vanes protect flocs and rate for decades of service.
Cons
- A fixed-geometry static mixer performs best across a set flow band, so wide flow swings need careful sizing.
- The two-stage 7000 needs more lay length than a single rapid-mix wafer.
Best for
Plants that need fast coagulant mixing in a tight footprint, or full inline coagulation and flocculation without serpentine channels.
Contact
Address: 15 Broad Common Road, Bristol, RI 02809
Phone: (401) 253-3799 or (888) 928-3747
Website: westfallstaticmixers.com
5. Kenics (Chemineer / NOV): the original helical mixer with low-headloss options
Kenics makes the original helical motionless mixer plus low-headloss HEV and WVM designs, giving water plants a proven element for coagulant mixing and gentle flocculation.
Company overview
The Kenics helical element is the one that started the category. The design traces to a 1965 Arthur D. Little invention, licensed to Kenics and now owned by NOV under the Chemineer name. Chemineer has built Kenics mixers for water and wastewater for over 30 years. The classic KMS helical element still serves small pipes and low-flow dosing.
What sets it apart
For low-headloss water duty, Chemineer introduced the HEV (High Efficiency Vortex) mixer in the early 1990s, then the project-optimized WVM range. It reports more than 1,000 full-scale HEV mixers, from 50 mm pipes to 6-meter open channels, running in water and wastewater plants worldwide. A pre-distribution tab spreads the additive at the pipe wall and, per Chemineer, improved mixture quality by at least 10% over a multihole sparger, with the biggest gain at very low flow.
Applications
Coagulant and chemical dosing, low-flow and gas-liquid dispersion with the KMS element, and low-headloss radial mixing for water and wastewater with the HEV and WVM designs.
Pros
- The original, widely studied helical element with decades of data behind it.
- HEV and WVM designs cut headloss for large water and channel duty.
- Backed by NOV, a large global supplier, for parts and support.
Cons
- The classic KMS helical element carries higher headloss, so large water jobs need the HEV or WVM version.
- Sold through a broad industrial parent, so water-specific support can vary by region.
Best for
Plants that want a proven helical mixer with a low-headloss option and global parts support.
6. Koflo: housed Blade static mixer with flexible injection options
Koflo builds housed Blade static mixers with chemical injection ports and NSF/ANSI 61 certification, a flexible choice for coagulant dosing, pH control, and chlorination.
Company overview
Koflo Corporation makes housed-element static mixers in a wide range of sizes and materials. Fixed Koflo Blade elements are edge-sealed to the pipe wall so fluid cannot bypass them, and removable 316L stainless elements are available for jobs that need periodic cleaning or extra rigidity. Clear PVC housings let operators watch the mix, and units carry NSF/ANSI Standard 61 certification for potable water.
What sets it apart
Flexibility on the injection side. Koflo mounts chemical injection ports in linear or radial patterns, in several sizes and flanged options, so multiple additives can enter the same mixer. Flow-straightening vanes cut the swirl after mixing with little added pressure loss, and heating or cooling jackets are available. That makes it a practical fit for coagulant and polymer dosing, pH adjustment, chlorination, and ozonation.
Applications
Coagulant and flocculant dosing, pH adjustment, chlorination, ozonation, and general chemical injection in potable and process water.
Pros
- NSF/ANSI 61 certified for drinking water, with clear PVC and stainless options.
- Flexible injection ports for staged, multi-chemical dosing.
- Removable stainless elements for cleaning and long service.
Cons
- A general-purpose housed-element mixer, not a staged coagulation-flocculation system.
- Very high-solids or delicate floc-growth duty needs careful element and material selection.
Best for
Plants that want a certified, configurable static mixer for coagulant dosing and chemical injection across potable and process lines.
Contact
Website: koflo.com
How we evaluated these inline mixers
Each mixer was rated on shear control, headloss, chemical savings, maintenance, materials, and the stage of the coagulation and flocculation process it fits best.
- Shear control. Coagulation wants high shear; flocculation wants low shear. Each mixer was judged on which stage it serves and how well it controls energy input.
- Headloss. Every static mixer trades mixing quality for pressure drop. Lower headloss means lower pumping cost, so low-headloss designs scored higher for the flocculation stage.
- Chemical savings. Even dispersion cuts overdosing. Documented reductions in coagulant or polymer use counted most.
- Maintenance. No moving parts is the shared advantage. Service intervals and clog resistance separated the field.
- Materials and fit. Pipe size range, material options for acids and caustics, injection hardware, and certifications like NSF/ANSI 61 were checked against real water duty.
- Track record. Verifiable installs, patents, and years in the water industry carried more weight than marketing claims.
Where each mixer fits in the coagulation and flocculation process
High-shear mixers like AquaShear and Westfall’s 2800 belong at the coagulant flash-mix, while low-shear designs like FRC, Statiflo, the 3050, and Kenics HEV handle gentle floc growth.
This is the part buyers get wrong. Ask one mixer to both scatter coagulant and grow flocs, and it will do one job badly.
Put the high-energy device first. A coagulant such as alum or ferric chloride needs to spread through the whole stream in the second or two before it hydrolyzes. That is where AquaShear’s opposing jets, Westfall’s 2800 plate, Koflo’s Blade elements, and Komax’s impingement element earn their place. This same high-energy zone is where polymer gets activated, uncoiled, and hydrated so it can work downstream.
Then drop the energy. Once flocs start to form, shear becomes the enemy. Low-shear designs, including the FRC pipe sweeps, Statiflo’s helical mixers, the Westfall 3050, and the Kenics HEV, move the water just enough to let flocs bridge and grow without breaking them. The Westfall 7000 and the FRC F-Series both pack the two stages into one inline run.
Match the mixer to the stage, and the chemistry does the rest.
Frequently asked questions
What is the difference between coagulation and flocculation in water treatment?
Coagulation neutralizes the charge on suspended particles using a fast, high-energy chemical mix. Flocculation then grows those particles into settleable flocs with slow, gentle mixing.
Coagulation comes first. A coagulant like alum or ferric chloride cancels the charge that keeps fine particles apart, and it needs a hard, fast mix to spread before it reacts. Flocculation follows, using slow motion and often a polymer to bind the destabilized particles into flocs big enough to settle or filter out.
Can an inline mixer handle flocculation without breaking the flocs?
Yes, if it is a low-shear or low-headloss design. Vane, helical, and pipe-sweep mixers grow flocs gently, while high-shear mixers are meant for the coagulation stage instead.
The trick is energy. A low-headloss vane, helical, or wide-radius pipe design adds just enough motion to bridge particles without tearing them. High-shear mixers, by contrast, are built for the coagulant flash-mix. Some products, like the Westfall 7000 and the FRC F-Series, stage both so the shear drops after coagulation.
Why use an inline mixer instead of a tank with a motor?
Inline mixers use the water’s own pressure drop to mix, so they have no motor, bearings, or seals to fail, and they cut energy use and maintenance.
A motorized flash-mix tank works, but it adds a motor, a gearbox, and a maintenance schedule. An inline mixer pulls its energy from the flowing water. That means less to wire, less to service, and a smaller footprint. For coagulant dosing and polymer activation, it often mixes faster too.
How much chemical can a better mixer actually save?
Even dispersion cuts overdosing at the injection point. AquaShear reports a 52% reduction in chemical use in field trials, and better mixing lowers coagulant demand across the plant.
Poor mixing forces operators to overdose so the weakest-mixed water still gets enough chemical. Tighten the mix and that safety margin shrinks. Savings depend on the plant, but the mechanism is real: the more even the dispersion, the less chemical you waste.
Which inline mixer is best for polymer activation?
High-shear hydraulic mixers activate polymer fastest. AquaShear reports 99% polymer activation in one second by uncoiling and hydrating the polymer in a single pass.
Polymer only works once its chains uncoil and hydrate. That needs energy, but not so much that it shreds the chain. A controlled high-shear mixer hits that window, which is why the opposing-jet chamber is built for this makedown step.
Which inline mixer is best for flocculation ahead of a DAF?
A pipe flocculator like the FRC F-Series is built for it. It stages coagulant and polymer, protects the floc with low-shear pipe sweeps, and can inject air before the DAF.
DAF capture depends on large, stable flocs reaching the flotation cell intact. The F-Series grows them inline with wide-radius sweeps that keep shear low, then can entrain microbubbles through air injection ports. For a plant built around DAF, that integration is the draw.
Which inline mixer should you choose?
For coagulant flash-mixing and polymer activation, AquaShear leads on speed and chemical savings; for floc growth, FRC’s DAF flocculator, Westfall’s 7000, and low-shear helical designs fit best.
Pick by stage, not by brand. To cut coagulant and polymer cost at the rapid-mix and makedown step, AquaShear’s hydraulic mixer does the job with no moving parts and a payback most plants see in under nine months. For coagulation and flocculation ahead of a DAF, the FRC F-Series is purpose-built, and the Westfall 7000 stages both jobs in one spool. Statiflo, Kenics, Koflo, and Komax each bring a deep water record and a low-headloss path for gentle floc growth.
To size a mixer for your coagulant or polymer dosing, request a quote from AquaShear at aquashearusa.com or call an AquaShear engineer at 432-999-8325.
Specifications and pricing change. Figures reflect manufacturer sources current as of September 2026. Confirm current specs and support with each maker before purchase.