Evodos Algae Dewatering Systems
February 21, 2011
he Evodos Spiral Plate Technology for separating micro algae, is based on centrifugal force, however the rotation is at much lower speed than conventional plate centrifuges. Both the fluid dynamics and the mechanical dynamics are completely different from conventional machinery.
The Evodos technology harvests at 3,000 times gravity. Particle count on feed flow and discharge flow, according to Evodos, show harvest at greater than 95% of the algae. The dry solid content of the produced algae-cake (after infra-red drying) is ~ 31.5%, so almost all extra-cellular water is removed. Microscopic evaluation shows that there is no thermal or shear damage to the algae. The system removes the extra-cellular water but not the liquids enclosed in the algae.
Running at 3000 times gravity, the energy demand of the system is ~ 1.3 kW H/M3 feed flow including the pump—well below the energy demand of high speed disc stack or decanter type centrifuges.
Evodos machines are completely self-contained, automated and need no infrastructure or sound protection. Units are free standing, with feed and discharge flexibly mounted. The process is PLC controlled and needs no supervision. All “wet” parts of Evodos machines are made from stainless steel.
The Evodos 2/25 series machine processes up to 13 GPM automatically. The enclosed low speed mono-type feed pump has frequency control allowing the machine to be tuned to the production level.
Evodos is coming out with a new model specifically designed for universities and for harvesting specialty strains at larger algae plants. This new model, Evodos 2/10, is a semi-automatic machine with a drum volume of 10 liters and a hydraulic capacity of 500-1000 l/h, based on their patented SPT technology. It has the same high performance as the Evodos 2/25 machine, however the 2/10 will require an operator. The detailed specifications will be made public at the end of first quarter of 2011, when it is available for sale. First deliveries will begin at the end of the second quarter 2011.
In order for Evodos to quote an accurate capex to demonstrate return-on-investment to clients, they request the following questions be answered:
- Harvested flow / hour.
- Operating hours / year.
- Type of algae and the size range (microns)
- Dry solid content (weight) of the live algae.
- Dry solid content (weight) of the harvested flow, directly from pond or PBR.
- Do algae deposit in a settling tank?
- Water temperature
- Water salinity
- Depreciation, % per year
- Interest, % per year
- Local energy cost rate, in kW/hour