Pipe Flocculator PPF

 

In a PPF flocculator the mixing energy for flocculation is obtained by the turbulence in the mixing unit and the pipe.

A coagulant is usually dosed to the raw water at the inlet of the PPF. Immediately after the dosing point a mixing unit is installed for the mixing of coagulant and raw water.

The reaction is completed in the pipe following the mixing unit.

Mixing energy and reaction energy in the mixing unit and the pipe are a result of turbulence (Reynolds number).

The PPF is characterized by the plug flow model. The retention time is almost uniform and mixing energy is constant in the pipe cross section as such all particles will be subjected to the same amount of mixing energy and for the same period. This will result in a highly uniform floc with excellent separation characteristics.

 

The flocculator can be provided with additional fittings for dosing of chemicals for neutralisation and dissolved air, in case of dissolved air assisted separation of the floc.

Coagulation is the destabilization of the polluted matter in the raw water. Fine particles are formed, which are not yet ideal for separation. Flocculation has to be added to obtain separable particles.

When the coagulation is completed a flocculant is dosed. Mixing of water and the flocculant takes place in a second mixing unit. The mixing energy in the mixing units is the most critical part of the flocculator, whereas the pipesections are providing the retention time to complete the reaction.

Floc growth will further be completed in the pipe following the mixing unit.

In this way a uniform, ideal floc can be formed for the separation of floc and water in a separator.