Insects have long been acknowledged as a rich source of protein, and they place a much smaller burden on the environment compared to animals that are traditionally farmed for meat. It is therefore no coincidence that process technology expert Hosokawa Micron is seeing a growing demand for insect-processing equipment.
Ashwin Jagmohan, Application Engineer Food at Hosokawa Micron, has noticed a rising interest in the company’s mixing and drying equipment for insect-based applications. “A growing proportion of the food and feed-related inquiries we receive are for the processing of insects such as black soldier fly larvae, mealworms, and crickets,” he says. “Another interesting area is the drying and milling of waste streams such as fish heads because of a more cradle-to-cradle mindset. At Hosokawa, we’re in an ideal position to help those customers if they require powder technology. Our Drymeister (DMR-H) flash dryer is widely used all over the world to turn products such as corn fibers, wheat gluten, starch, shrimps, krill, and so on into a high-value protein powder – and it’s perfectly capable of doing the same with insects and by-products.”
Drying, milling and classifying in one
The Drymeister combines drying, milling, and classifying in one efficient and continuous process step. The material is fed into the grinding and drying section of the dryer’s main body. The Drymeister can cope with various kinds of wet feed material, from slurries and pastes to whole insects. The grinding rotor disperses the wet material into fine particles, which are fluidized in the grinding chamber by hot, temperature-controlled gas. The system is kept under slightly negative pressure by the exhaust fan, and the surface area of the product is increased so that the moisture is evaporated instantaneously. The gas stream conveys the particles to the top section of the dryer where a classifying wheel selects the particles by size. Then the particles are conveyed with the exhaust air to a powder-air separating system such as a cyclone and pulse-air filter.
Overcoming the challenges
Insects can be difficult to handle when wet because of poor flow characteristics and cohesive tendency, plus they are temperature sensitive. The DMR-H overcomes these challenges easily, however. “The Drymeister has been engineered to dry highly moisturized material in a matter of seconds without damaging the delicate proteins. The system runs at a high air inlet temperature of up to 300 ⁰C, but actually heats the solids to no more than 90 ⁰C; the energy is focused on evaporating the water, so the nutrients and other properties are retained,” states Ashwin. The Drymeister also offers impressive flexibility: “There are lots of different process parameter settings that can be adapted to achieve the optimal particle size and moisture content – from the speed of the mill disc and the classifying wheel to the feed rate, the air temperature, and the airflow. If desired, we can produce a fine powder with as little as 0.5% moisture in the end product.”
“Thermal drying processes use lots of energy. Our Drymeister is already very energy-efficient, but we’re continuously calculating for maximum energy reduction for each industrial system we offer,” continues the application engineer. “For example, with our economizing step we’re able to preheat inlet air with exhaust air in a closed-loop configuration. Besides that, effective insulation materials allow us to achieve considerable energy recovery.”
Another benefit of the Drymeister is its small footprint – it is around 75% smaller than ring dryers or spray dryers. Furthermore, the Drymeister offers good accessibility for cleaning, inspection, or maintenance purposes.
Insect farmers have to meet certain quality criteria with their products. But the quality of insect harvests can fluctuate due to seasonal influences, for example, which means that each harvest can have a different size, nutritional quality, and so on. “Therefore, insect farmers can use our batch mixing technology to mix several batches of insects to achieve a consistent overall quality level,” says Ashwin. “Moreover, all our conical paddle mixers (CPM) and Nauta® mixers can be executed with a liquid injection system. This can be used for adding flavorings, colorings, or oils during the mixing process. So we can support powder/powder and powder/liquid mixing in line with whatever type of insect-based product is needed for further processing.”
All potential insect-based applications are extensively tested at Hosokawa’s in-house test center, which is unique in Europe in terms of its size and diversity.
The Hosokawa Micron Group is an international supplier of machinery, systems, processes, and services for the field of powder and particle processing. A multitude of different specialists combines knowledge and experience in the Hosokawa Group to find optimal solutions. Regardless of the size, i.e. production-scale systems, pilot systems, or laboratory ...