Agitators for digester
Depending on the shape of the digesters, top entry, side entry and also inclined agitators are used.
The most frequent are top-entry agitators that are used for the height of liquids higher than the diameter of the tank.
- Specific design for each project.
- They ensure the homogeneity of the entire tank content by recirculating the fluids from bottom to top.
- They prevent the formation of crusts and reduce inert solids at the bottom.
- Easy to assemble.
- Low power consumption and very high efficiency.
- Simple and inexpensive maintenance.
- Height-adjustable propellers along the axis.
GEARED MOTOR of leading brand, with protection against explosion by the emission of gases during fermentation. ATEX.
WATERPROOF, labyrinth type hydraulic lock, with safety system always full. Manufactured in stainless steel. Possibility of installing mechanical seals on request.
SHAFT in several sections with flanged connections that facilitate the assembly. Manufactured in stainless steel.
SUPERIOR PROPELLER Type PD12. Prevents the formation of crust on the surface, favouring the rise of methane. Manufactured in stainless steel.
LOWER PROPELLER. Larger diameter PD10 type. They are high performance mobiles with a low percentage of turbulence. They generate large flows with very little shearing. Manufactured in stainless steel.
As an alternative to top-entry agitators with large shafts, chimneys can be used that direct the flow of the sludge and suck it from the bottom.
This has the great advantage of minimizing the dimensions of the agitator and therefore the costs. In this case there is only one mobile located in the highest part of the chimney.
G&G digester agitator at Ibarra WWTP in Ecuador
G&G Ingenieros has supplied, through the consortium Acciona Agua-Eduinter, a 9.2 kW Top-entry agitator for sludge digestion at the Ibarra wastewater treatment plant in Ecuador.
The WWTP has been designed following a rigorous plan of environmental protection through an advanced system of biological purification of nutrients.
Mixing is very important in a digester because a good mixing equipment accelerates digestion because it achieves the following objectives:
- Maintenance of the homogeneity of the reactor content.
- Prevention of crust formation.
- Maximum use of the total content of the digester and reduction of inert solids in the bottom.
An agitator installed in a digestion tank suspends the organic material and prevents the formation of a floating film or crust. The purpose of the agitator is to create a vertical recirculation from bottom to top, for this and due to the large size of the digesters is placed a vertical agitator with 2 propellers, one at the bottom and the other on the surface of the fluid, as can be seen in the following drawing.
The propeller located on the fluid surface is the one that will prevent the formation of the crust, which can be dangerous because it makes the methane not go to the surface of the reactor.
The agitator must have an ATEX motor due to the high presence of methane in the reaction.