Are you tricantering my man? Three-in-one for the price of two

World Fishing trawled back to August 1999 and found a lesson to be learnt from Klaus Ertl of Germany-based Flottweg, a company with family links to the BMW car startup a company in 1900. Klaus puts the case for learning a lesson from South American fishmeal processors.

"Years ago it was claimed that there was no application for the technology of tricanters in the fish processing industry. But recent experience has proved this wrong. Nobody believed this at the start of the 1990s, when the fishmeal industry was trying to introduce tricanter technology. The critics said it would contribute little to efficiency and competitiveness in the fish industry.

Back in the early 1990s, common arguments put forward against a tricanter included: 1. You cannot point to a fish-processing plant anywhere using this technology. 2. It is impossible to make one single machine do the work that has had to be done with a two-phase decanter plus a separator. 3. No one has invented the technology to control process parameters such as liquid-liquid-separation in the tricanters.

Yet, South America now has a high number of tricanters in the fish industry showing critics were wrong. They give excellent separation results and improvements in the quality of the fishmeal and fish.

So what is a tricanter?

Our three-phase decanter, FLOTTWEG TRICANTER®, is able to separate two different liquid phases and one heavy solids phase in only one separation step. The two liquid phases form one inner and one outer layer of liquid and these are discharged separately through different exit valves so they do not cross-contaminate each other. Gravity does the work of discharging the light liquid phase into the housing of the machine. The heavy liquid phase is discharged through a variable impeller, allowing the operator to optimise the liquid-liquid-separation during the process.

The biggest advantage of the tricanter is the ability to have only one single machine to separate solids, stick water and oil phase in one simul-taneous separation step.

Compare that with the conventional system where you have a pre-separation of solids taking place in a two-phase decanter. Then you have to separate the discharged liquid, oil and stick water, in a second machine -- a separator.

The tricanter is fed with the fish press liquid from the screen and the press. Under the influence of centrifugal force, the incoming three-phase of solids, oil and water, are separated according to the different densities of the phases.

Economic advantages

You cut costs for the fishmeal and fishoil scenario because you do not need a feed pump to decanter (fish press liquid from press and strainer), a pump for clarified press water from decanter, a buffer tank for clarified press water (feed to separator), a feed pump for separator, a heat exchanger for mixture, oil and stick water, a pump for the solids discharge separator and a movable water system and cleaning system for the separators. And that is before higher installation, operation and maintenance costs which are avoided with the tricanter. For sardines, a tricanter can handle 80 per cent more than a press. And quality goes up because the raw material is processed for far less time, high temperature damage is reduced and fish oil comes out at 99.8 per cent quality. South American experience also shows a final fish meal with low fat content."