Use of Centrifuges for Rendering

If your business operations entail conversion of animal waste into more useful, value-added materials like lard or tallow, then you know how essential a centrifuge is to accomplishing that aim. Maybe you are on the hunt for a new, reconditioned or used centrifuge to replace your current one, or perhaps you are entirely new to the world of rendering. Either way, shopping for a centrifuge can be confusing. We hope this primer will help make the purchasing process less baffling for you.

The first question you may be asking yourself is whether it matters if the tallow you are rendering is edible or inedible. Obviously there are certain regulations that will need to be met when dealing with edible byproducts. However, the rendering system options are the same.

Following are the three general types of centrifuges that are used in both edible and inedible rendering.

Method #1: Autoclaves – A strong, heated container used for chemical reactions and other processes using high pressures and temperatures, autoclaves have, in most situations, been replaced by other rendering systems. However, there may be very specific instances in which you want to use this particular type of centrifuge in your rendering processes. That’s where dealing with a seller of used and reconditioned process equipment can really work to your advantage. Case in point, Aaron Equipment currently has almost two dozen autoclaves in stock and we try to maintain a constant inventory.

Method #2: Dry Rendering – A process of cooking animal tissues in the absence of water for extraction of the fat, dry rendering is just how it sounds: it is a dry process. As a result, the centrifuges used to accomplish the fat extraction have their own unique processes. Dry rendering is also the most commonly encountered rendering methodology in use today. It has two subsets: batch dry rendering and continuous dry rendering. With both of these methods, the tallow is typically removed by pressing—either hydraulic or screw.

Dry rendering centrifuges offer several advantages. The centrifuges used are more economical when it comes to the energy they consume. They also provide a better protein yield. Processing is faster with these rendering centrifuges as well. And finally, much of the stench involved in the tallowing process is eliminated. Super helix centrifuges offer continuous dry rendering while basket centrifuges are more typically designed for batch dry rendering.

Method #3: Continuous Wet Rendering – Because it produces a premier grade fat and edible meat fractions, this rendering process is the most frequently encountered in edible tallowing. Unlike continuous dry rendering, it involves a short contact time between the water used and the raw material. As a result, the tallow quality does not have time to degrade. The centrifuges used in continuous wet rendering are decanter and disc types. The decanter centrifuge process occurs first, where the liquid phase offers further treatment and the meat fractions are taken away. The second phase involves the disc type centrifuge, whereby remaining water and fines are removed from the fat. This type of rendering process yields 99.7% edible fat.

Aaron Equipment’s centrifuge expert, Whitney Craig, can be contacted for advice and help steer you through your many centrifuge options from decanter centrifuges to bottom dump centrifuges. Whitney also has expertise in disc and filtering centrifuges.

Feel free to connect with Whitney on his Centrifuge Specialist Facebook page or on LinkedIn.