ROYAL DUTCH KUSTERS ENGINEERING
The New, High-Quality Black Soldier Fly Larvae and Frass Separator

When Black Soldier Fly Larvae are fully grown, it is time to harvest them before they transform into prepupae. By harvesting, the larvae are separated from the remains of the (food) waste and insect manure, the so-called frass. This is where the Royal Dutch Kusters Engineering Rotoshifter comes in.
Manual versus automated sieving
Manually harvesting Black Soldier Fly Larvae (BSFL) can be very time consuming and requires the presence of one or more operators. Moreover, it is impossible to reach the same shaking frequencies as automated shaking sieves. The mesh size of the sieve should be smaller when manually sieving, which means it takes even more time to separate the frass from the larvae. Even more so, sieving can require multiple sieving steps. Finally, higher moisture levels can cause separating problems and could even require a different separating method.

Alternative to sieving
But there is a third way: The Royal Dutch Kusters Engineering Rotoshifter separates BSFL using air and rotational forces and several drum screens simultaneously. This system combines two proven technologies into one, ensuring the larvae are efficiently separated from the frass.
Five benefits of the Rotoshifter technology:
- High-quality separation
- Less loss of fresh larvae in frass
- Easily adjustable to match the input
- Low energy consumption
- Small footprint
High purity level and customizable capacity
The Rotoshifter reaches a purity level of clean larvae of 97,5 to 99,0%, assuming the systems’ variables are optimized for purity. Moreover, the maximum moist levels of the mix of BSFL
and frass could be up to 60%*. The purity level of the frass could be up to 99,9%.
*material depending
“Its customizable settings make the Rotoshifter fit in nearly any insect rearing process..” – ROYAL DUTCH KUSTERS ENGINEERING
Finally, the throughput capacity of the Rotoshifter is available in various models with different diameters and lengths. Royal Dutch Kusters Engineering can provide solutions for 0,5 up to 20 m³ per hour.
Furthermore, Royal Dutch Kusters Engineering can also provide a system to optimize the feed efficiency of the larvae. The Organic Liquefying Press separates organic waste from other (inert) materials to gain virtually pure organics.