Different types of process agitators are required in water treatment plants.
All these industrial water agitators are subjected to continuous operation under demanding conditions. They must therefore be robust agitators to ensure long-term fault-free operation.
G&G Ingenieros studies and offers optimized agitators.
Using high-performance slim profile (PD) mobiles and energy-efficient motors.
The objective is undoubtedly to minimize the energy consumed and reduce the environmental impact.
The fields of application are for example:
- Coagulation and mixing.
- Suspension of solids.
- Destratification and recirculation.
- Nitrification / Desnitrification.
- Preparation of flocculants.
- Preparation of lime slurry.
- Preparation of reagents.
- Homogenization of sludge.
Coagulation and mixing
With the name of "flash mixing" the operations of mixing the water to be treated with reagents are known.
The objective is coagulation, which consists of destabilizing colloidal particles by neutralizing their electrical charges.
It is therefore a matter of mixing the reagents (metallic salts of aluminium or iron) intimately with the water to be treated.
This mixture must be fast as the coagulation time is very short and it is necessary to avoid that the reagents react and precipitate.
The use of thin-profile propellers provides the advantage of high performance.
In other words, under the principle of generating a sufficient minimum turbulence and recirculating the entire fluid mass through it, the same mixing result is achieved as with a generalised turbulence to the fluid mass, but with much lower installed powers.
Suspension of solids
To make the suspension of solid particles in a liquid, the agitation mobile must exert an energetic action on the bottom of the tank to provoke the sliding and rolling of the particles.
It is then necessary that the circulation of the liquid is sufficient to be able to drag the particles within the liquid phase.
This characteristic value used to define the suspension of solid particles in the liquid phase is the minimum rotation speed of all the particles on the bottom of the tank.
At G&G Ingenieros we recommend the use of large diameter axial propellers, which also allows us to limit abrasion phenomena.
Flocculation is the intermediate operation between coagulation and decanting in water treatment.
Therefore, once coagulation has been carried out, which consists of destabilising the colloidal particles by neutralising their electrical charges, it is necessary to join these particles by forming flocs to favour their decantation and separation.
What do we need to achieve?
Water and wastewater agitators It is necessary to suspend the floc sludge and generate its movement throughout the liquid mass with the highest possible flow.
Therefore, the obvious limitation lies in the fact that the velocity gradients generated do not cause a shear that breaks the floc and opposes the desired objective.
Then, the solution is to place agitators with axial flow propellers.
In the case of flocculation in several stages, it is recommended that the flocculators are of decreasing speeds, since in the first stage it is where more agitation is needed as the flocs are smaller, even with the risk of a certain breakage.
In the following stages, the apparent density of the flocs will decrease and lower speeds will suffice to suspend them, thus favouring the fattening of the more sensitive or less cohesive flocs.
G&G Agitators at PTAR in Panama
G&G Ingenieros has supplied 2 top entry Agitators of 3kW for Coagulation through its client Degremont for the Wastewater Treatment Plant that is generated in the metropolitan area of Panama City, before unloading them at the mouth of the Juan Díaz River.
G&G Agitators in ETAP Montfulla
G&G Ingenieros supplied through its client Degremont 2 top entry agitators of 4kW for mixing and coagulation for the Montfulla drinking water treatment plant.
Vertical agitators for the Cabrutica Water Treatment Plant
G&G Ingenieros has supplied several agitators to Petróleos de Venezuela, S.A.
They have been supplied through their client Ondeo Industrial Solutions.