Cooling of post extruded products is important, especially as it relates to the production of Full Fat and ExPress Soy.
Acceptable levels of urease and trypsin inhibitors, achieved during extrusion, are reactivated if the product is sent to storage before it is properly cooled. This will result in poor performance and possible digestive problems in the animals being fed the product. It can also cause storage problems such as steeping, discoloration and flowability.
Proper cooling can be challenging when outside temperatures are over 100°F. Industry standards say that product going to storage should be less than 120°F.
To achieve maximum dwell time in the cooler, you should have a minimum of a 2 inch drop from the inlet to the outlet of the cooler. This adjustment is made by turning the threaded bolts on the bottom of the cooler up and down as needed.
It is important to maintain a minimum 2 inch drop. Less than 2 inches can cause overloading. This results in stress to the center shaft, gear box and drive motor, or meal leakage at the inlet side of the drum.
In case of a power failure, the cooler should be cleaned out before restarting. Starting the cooler under a load can stress the main shaft to the point of breakage.
Airflow is adjusted with a damper that is located in the plenum, positioned behind the meal inlet. Adjust for as much airflow as possible, without sucking meal out of the cooler drum.
Check the cyclone outlet to see how much meal is being pulled through the air ducting. Because of the oily nature of the product, meal can stick to and build up on the inside of the whole cooling system.
The inside of the cooler drum should be cleaned at least once a week, as should the fan blades of the fan impeller. The ducting should also be inspected regularly for build-up. Finally, always make sure the cyclone outlet is open and free flowing.
Proper cooling is critical to maintain quality in the finished product. So, pay close attention!