Wednesday, October 8, 2014

08/10/2014: RAS water technology overview - Faivre Drum Filters

The operating system is simple. The water to be filtered is directed into a rotating drum. The outer surface of the drum is manufactured with a number of stainless steel plates covered with stainless steel (or Nylon) mesh plates. Suspended solids larger than the perforations are unable to pass through the mesh and thus, are retained in the drum.
 

http://issuu.com/international_aquafeed/docs/current_issue/32

The slowly rotating drum separates the solids from the water and discharges the solids through a discharge channel located at the top of the drum as indicated on sketch.

FAIVRE filters are designed to resist to all corrosion, due to their construction entirely of stainless steel type AISI 304L for fresh water, and type AISI 316L for salt water. All parts of the filter have been engineered and calibrated for their specific duty.

FAIVRE drum filters are manufactured with less moving parts as possible. The drum is driven by belts so as maintenance is reduced to a minimum.

The efficiency of the design is contained within the construction of the stainless filter plates that are integrated into a strong stainless steel framework. Replacement of filter plates is operated in a few minutes due to the exclusive design. The filter plates are easily cleaned and re placed on the drum.

FAIVRE offers a complete range of efficient filters, strongly made and economic to
operate.

Primzone Ozone
Research shows that water treatment with ozone increases productivity at RAS aquaculture systems.

Three reasons why ozone in aquaculture improves water quality and increases aquaculture productivity.

As recirculating aquaculture systems (RAS) operate by reusing the fish tank water it is essential to control the water quality. Many studies show that treating RAS systems with ozone increases productivity as fish health and survival is increased.

At RAS the organic load tend to be high and the homogeneous fish stock leads to a high risk of infections and problems with bacteria, fungi and viruses. Although ozone is not primarily used for disinfection at RAS the reduction of solids and DOC often creates an environment that is less favourable for bacterial growth and thus creates a reduced need for disinfection.

1. Removal of colloidal solids with ozone micro flocculation
The organic load is a constant concern for RAS systems, especially when the fish density is high and the water exchange rate low. Oz one has the ability to cause clumping or micro flocculation of fine and colloidal solids, which in turn facilitates removal by filtration and sedimentation.

2. Removal of dissolved organic compounds Ozone changes the characteristics of the dissolved organic compounds (DOC) by oxidation and precipitation that makes it easier to
remove the DOC by bio filtration and sedimentation.

3. Turn lethal nitrite into harmless nitrate with o zone treatment A high organic load is a favourable environment for nitrite growth. When reducing the organic load with ozone treatment the risk of n itrite growth is also reduced. Ozone also has the ability to oxidize nitrite to nitrate.

Suffer with any of the above problems with water quality at your RAS plant? Contact our Aquaculture Specialist Dan Johansson.


Read more HERE.

The Aquaculturists
This blog is maintained by The Aquaculturists staff and is supported by the
magazine International Aquafeed which is published by
Perendale Publishers Ltd

For additional daily news from aquaculture around the world: aquacutlure-news

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