How Do You Apply A Pelleting Aid?

Pelletizing is the process of converting finely ground feed into dense, free-flowing pellets or capsules. In this section, we'll delve into the art and science of pelletizing. Learn how the industry got started, how pellets are made, and what components and aids are needed to produce high-quality pellets.

1. The history of animal feed pelleting

For centuries, people allowed their pigs and chickens to forage for food, occasionally throwing them some food scraps. The industrial revolution changed that.

Farmers now need horsepower. Horses that provide power need high energy feed. Horses providing transportation needed to have feeding stations along the way. Horses that went to war had to carry feed with them.

The British developed the first compound feed as transportable nutrition for war horses. This feed resembled large baked cookies and was a mixture of oats, peas, rye, flax, wheat or corn. According to feeding experiments conducted by the Prussian Army, 1.5 kg (3 3/8 lbs) of this compound horse feed could replace 5 kg (11 lbs) of oats.

The concentration of food processing, especially in large flour mills, created a new environmental problem: these mills (conveniently built near water) began dumping waste into rivers and streams.

Pellet Mill

As tons of wheat intermediate grains polluted the waters, the government intervened and banned dumping by law. Intermediate grains have nutritional value for animals, but are not pleasant to eat because of their poor fluidity, low bulk density and dusty texture. Whey from cheese production and meat and bone meal from packing plants were equally problematic.

The need for efficient animal feed and industrial food waste utilization were both greatly met in 1928 when Purina began pelletizing flour mill wastes. Wheat flour was mixed with animal by-products or bean cakes, combined with ground corn and minerals, and then pressed into convenient pellets. The obvious advantages are

Less dust

Increased stacking density

Improved flowability

Improved palatability

Reduced feed waste

Increased consumption rate

Less energy consumed

Dense minerals are not separated out

2. How do I use pelletizing aids?

All pelletizing aids are available as powders or liquids. Powders should be added to the mixer at the same time as the other intermediate ingredients. Liquids can be added to the mixer or applied in the conditioning chamber. There is much debate as to which method is best.

Consider a commercial feed mill that produces pellets for a variety of species. This plant may have several presses with production rates ranging from 2 to 10 tons per hour (TPH), and the same 3-ton blender can supply all the presses. In that case, adding to the mixer can supply pelletizing aids to any of the three presses with a single application system. If the dosage is 1%, it may be easy to add 30 kg of liquid granulation aid to the mixing cycle. However, if the liquid is very viscous, effective mixing may be difficult to achieve. Another advantage of applying on a mixer is to be sure that the correct dosage is included.

Now consider an integrated granulator that runs two presses at 50 TPH, both supplied by a 10-ton mixer. Adding 1% of granulation aid to the mixer requires 100 kg per batch. This can be difficult to apply and mix in short mixing cycles. Adding 1% liquid granulation aid to the conditioner means a speed of less than 1 liter per minute, which requires smaller pumps that need to be integrated into the control system. In addition, when liquid granulation aids are added with steam and mixed in the conditioner, the distribution is continuous and uniform. Adding a regulator with a variable speed pump makes it easy to change the dose as needed. Of course, the formulator may be resistant to any changes of this type.