298 94 307/02 Untersuchungen zum Stand der Umsetzung des ...

Teil 3 Seite 8-27
For the wastewater from the meat meal industry, mainly sludge catchers, fat separators,
sieve rakes, micro-strainers, and also settlement tanks are used. As a rule, the mechani-
cal stages in the mainstream are implemented before any mixing or equalisation tank.
The fat separation can prove to be considerably difficult, as the animal fat contained in
the wastewater can occur in the finest of forms. This is particularly the case when the
temperatures are high and when the wastewater also contains tensides. High pH-values
do also impair the fat separation due to the saponification effect.
Fat separators before the mixing and equalisation tanks must be dimensioned for the
maximum wastewater production, that is not for the equalised production. This maximum
production occurs, for instance, during the exhaust vapour relaxation. Moreover, the fol-
lowing items must be considered for the dimensioning:
- Temperature
- Influence of rinsing and cleaning agents
- Production of the different kinds of fat to be separated and their density.
In many plants, the fat separator is followed by additional strainer units with sieve aper-
tures of 0,5 to 2 mm for an even more extensive solids separation.
8.2.3.2 Recycling of all process waters to the raw material (Kurztechniken
C.)
Example plants
Corporate clarification plant of the Kraftisried animal carcass disposal plant,
87647 Unterthingau
Corporate clarification plant of the East Bavarian Meat Flour Association,94447 Plattling
Corporate clarification plant of the Eiweiß- und Fettverwertung GmbH & Co, 49191
Belm-Icker, Germany
Clarification plant of the Union for Animal Carcass Disposal (Zweckverband für Tierkör-
perbeseitigung) Lenz, 01561 Lenz, Germany
Rethmann TBA Genthin GmbH, 39307 Mützel, Germany Oberding animal carcass dis-
posal plant, Germany
8.2.3.3 Separate thermal desinfection for the whole waste water of the
"dirty areas"; exhaust air temperatur