Page 38 - Commercial Catalogue 2011

This is a SEO version of Commercial Catalogue 2011. Click here to view full version

« Previous Page Table of Contents Next Page »
33 Commercial Catalogue
Tel: +44 (0) 1923 284151 www.tropicalmarinecentre.co.uk
Skimmers for Saltwater Applications
TMC Protein Skimmers
Tropical Marine Centre System Protein Skimmers are designed for the effective removal of dissolved
proteins and other organic matter.All units feature venturi gas injection via an included dedicated venturi
pump and are suitable for use with ozone.
Process water enters the top of the reaction chamber through the side of the unit and leaves under
gravity via an external exit pipe.A gate/ball valve on the exit pipe is used to control the water flow and
foam height inside the skimmer.All units are designed to be sited alongside or above a system reservoir.
All Tropical Marine Centre System Protein Skimmers feature our unique, flexible double o-ring inlet and
outlet boss system for easy service and the simple removal and replacement of pipework and
components.
Protein Skimming/Foam Fractionation
Protein skimming, or foam fractionation, is the process by which dissolved and particulate organic
carbons are removed from a liquid, in this case the fish culture water, by adsorbing them onto the
surface of fine bubbles rising in a closed contact column against a counter-
current water flow.The bubbles burst and form stable foam at the top of
the water column and the accumulated organic wastes are discharged from
the column along with the foam produced.The removed substances are
called “surfactants” because they are surface active or “charged”.
Benefits of Protein Skimming include:-
• Removal of suspended solids
• Removal of proteins and high molecular weight compounds
• Increased water clarity through removal of humic and phenolic
compounds
• Increased oxygenation of the culture water
• pH stabilisation through removal of organic acids
The performance of the protein skimmer is dependent on many factors:-
• Salinity
• Air to water ratio
• Air bubble diameter
• Column height
• Air/water contact time
• Use of ozone
Bubble size is the most important of these and within the control of the design of the protein skimmer.An
efficient air diffuser or venturi plays an important part in generating a swarm of bubbles that are as small
as possible, ensuring maximum surface area for adsorption of the organic compounds. Smaller bubbles
also rise more slowly, allowing more contact time with the process water. Generally it is difficult to
generate a small enough bubble size in freshwater to achieve effective foam production (except in cases of
very high organic loading) and therefore protein skimming is mainly only recommended for seawater or
brackish applications where the salinity is more than 16 ppt. However a number of freshwater skimmers
are available for use in ponds. Protein skimming is further enhanced by the application of ozone into the
air mixture, which further oxidises and breaks down complex organic compounds as well as providing a
degree of disinfection, depending on the quantity used. For further information on ozone
p.40
Water outlet
Water inlet
Air inlet
(counter-
current)