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

Economics
Driving force for implementation
Example plants
Teil 3 Seite 8-20
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 disposal plant, Germany
Reference literature
8.2.1.3 Drying
8.2.1.3.1 Description of the methods
The broken-up and sterilised material can be dried discontinuously or continuously. Dur-
ing the drying process, the viscosity increases the more the less fat is contained in the
material. This is the reason why the fat is only very rarely cut off prior to the drying, as had
been done in the wet method. In many cases, fat is used additionally during the drying.
The following drying systems are used:
• continuous disk dryer with or without fat addition
• recirculation dryer
For the stirring dryers, which are designed for filling amounts from 1 to 15 t, the drying
time is 2,5 to 3,5 h. Their construction resembles that of the stirring implements for the
sterilisation. For the continuous drying, double-walled cylinders with installed stirrers are
used, the shaft of which is heated as well. The material is extracted at the end of the dryer
with a conveyor screw. The processing capacity is 2 to 4 t/h, with a contact time of approx.
45 minutes.
The disk dryer is a lying apparatus which is equipped tightly with heatable disks and a
stirrer. The capacities amount to 8 Mg/h for fat-containing material or 4 t/h for material with
low fat contents.
In contrast to all other dryer types, in the grinding drying heat is supplied directly via
heating gas. This type is no longer used today, because of the high energy demand and
the problems with emerging odours. However, there are modern dryers of this type, which
are designed as closed unit where the used dry air is fed back into the air heater via a
Venturi washer unit (so-called flash-dryer). The material to be dried is there conveyed