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How Does a Destoner Work?

We often emphasize the importance of properly cleaning your incoming material in order to produce the highest-quality meal. As the old adage goes “garbage in, garbage out.” The extruder is not a magical machine; it responds to the inputs that it is given. Beyond simple cleaning, the next best thing to do in preparing beans for extrusion is to use a destoner.

 

How Is It Different?

Some might think they can get by with cleaning only. In specific instances, this may be correct. A cleaner will separate stones from soybeans, but the main method for doing so is by size only.  What if there are stones that are the same size as the soybean itself? This is where the destoner comes into play.

 

Installed Destoner

 

Destoners operate using the idea of a fluidized bed to separate material based on their bulk density. Bulk density is the material weight per cubic space it takes up. This is typically expressed as pounds per cubic foot or kilograms per cubic meter.

 

Destoners have a large table that vibrates at various frequencies that can be tilted up or down.  Tilting the destoner makes it possible to adjust how fast the material moves.  Additionally, there is a fan blowing through the table to help fluidize the material.  The key with this machine is the frequency – similar to a retention time setting

 

Once dialed in, the stones will bounce and move in one direction while the beans move another. The stones will actually travel uphill if properly set! The stones will fall out of the back of the machine and are usually collected in small buckets due to the low volumes, but could easily be routed to a trash carrying conveyor out of the building.

 

Image courtesy of Oliver Manufacturing 

 

Is It Necessary?

We get this question often and it ultimately comes down to your supplier of beans. If you know they do a thorough job of pre-cleaning, there may not be a need for a destoner after the cleaner. Though, it’s always better to be safe than sorry. Think of it as insurance to reduce potential wear on your extruder parts. In some parts of the world, it is known that suppliers will add stones to bags in order to make them heavier!  Having extra protection will increase part life and the quality of your end product. Interested in learning more about destoners? Send us a message.