Static mixers: homogeneous mixing without moving parts
Injecting a chemical into the line is not enough — it has to mix. A static mixer does this with the energy of the flow itself, with no motor and no maintenance.
The pump may be correctly selected and the injection valve in the right place, yet the chemical can still travel down one side of the pipe. The analyser reads it as “under-dosed”, the dose is increased — while the real problem is mixing.
How it works
A static mixer is a set of fixed elements inside the pipe. As the flow passes over them it is divided, rotated and recombined. There are no moving parts; the energy for mixing comes from the flow itself. The price is a small pressure drop, which is accounted for in the design.
Where it is used
- Disinfection: even distribution of chlorine, chlorine dioxide or hypochlorite solution in the main line.
- Treatment: coagulant and polymer blending, acid/caustic dosing for pH correction.
- Industry: colour, additive and resin blending; gas–liquid contacting.
- Open channel: channel-type mixers for unpressurised flows.
Three things that decide the selection
- Mixing quality: the required homogeneity (coefficient of variation) sets the number of elements. The closer the measuring point, the better the mixing must be.
- Pressure drop: it must be included in the pump head calculation.
- Material: housing and elements are chosen for the fluid and chemical — stainless steel, PVC, PP, PVDF and special alloys.
A practical rule
If the distance between the injection point and the measuring point is short, always use a static mixer. Otherwise the analyser sees only one part of the cross-section, the control loop works on wrong data and the system keeps over- or under-dosing.
Hidrodos has represented Statiflo static mixers in Türkiye since 2015. Let us determine the right type and element count for your line — get in touch.
