F-Series Flocculators are Top Performing Chemical Reaction Vessels
Flocculators, per their namesake, are designed to provide the mixing action and retention time required to adequately coagulate and flocculate solids in wastewater. FRC Systems, a JWC Environmental brand, takes floc tube design very seriously, as they have a dramatic effect on the separation efficiency of solids in a Dissolved Air Flotation System.
As with all FRC systems, great detail has been given to each design element of the F-Series Flocculators, making them arguably the best performing chemical reaction vessels on the market.
How Flocculators Work
The main objective of a flocculator is to mix coagulants and flocculants into wastewater and form floatable solids. The main components include a frame, inlet, sample ports, injection ports, pipes, and an outlet. The pipes are configured in a climbing, serpentine manner to reduce the amount of floor space needed to provide sufficient chemical reaction time.
What occurs in a flocculator is conceptually quite simple:
- Water is pumped under pressure into the inlet of the flocculator.
- Immediately after the inlet, injection ports are provided for chemical dosing, typically coagulants.
- After several pipe runs, a flocculant polymer is injected and mixed in the subsequent pipe sections. Some units come with an inline pH meter and injection points for neutralizing agents.
- Ultimately the water exits the flocculator and flows into a DAF unit.
Of course, FRC F-Series Flocculators have several unique design features that give them added process advantages.
Inline Mixing Zones
How and where chemicals are mixed in a pipe flocculator has been debated in various technical forums. Some manufacturers advocate high turbulence and shear forces at 90-degree elbows in the pipe turns. They say that this causes back-mixing and aids in floc formation. FRC, however, argues that this approach is contradictory to the fundamental design philosophy of pipe flocculators – to simulate a singular, straight run of pipe.
To achieve proper mixing, FRC employs inline mixing zones by reducing and expanding the pipe diameter over a short pipe run. This accelerates flow-through velocity and disperses chemicals in and immediately after the mixing zone (see red zones in diagram). Chemicals are mixed where and how we want them to mix.
Air Injection Ports
As flocculant polymer is dosed into the flocculator it starts grabbing onto coagulated particles and forming larger solids. By adding micro bubbles to the mix, the polymers actually wrap around the bubbles, entraining air pockets within their structure. This effect is like wrapping a wet towel around a beach ball submersed under water – as soon as it’s released it floats to the surface.
This design feature allows for faster separation in a DAF vessel. Faster separation means you can use a smaller tank. And a smaller tank means a smaller price tag.
Wide-Radius Pipe Sweeps
For the exact opposite reason manufacturers use tight 90-degree elbows in their pipe turns, FRC employs sweeping, wide-radius fittings. Where others want to exact shear forces and create mixing action in the turns, FRC aims to eliminate shearing so that flocs can grow larger and fluffier over the rest of their retention time in the flocculator.
By not shearing flocculated solids after they’ve been formed, operators end up requiring less chemicals to achieve the desired level of separation and clarification.
- Improves separation efficiency of solids
- Inline mixing zones accelerates flow through velocity
- Air injection ports allows for faster separation in a DAF vessel
- Use less chemicals to achieve the desired level of separation and clarification
- Flow Rates range from 7 to 2,000 gpm
- Materials of Construction: PVC/HDPE/SS or HDPE/SS