The design of a premix, compound feed or petfood production facility has one main goal: how to get all the raw materials into the end product(s). Of course in an accurate, time- and cost-efficient and flexible fashion with the desired capacity and footprint, while respecting any contamination groups. And last but not least, within budget.
So there’s of course a lot more than just the one goal while designing the ideal process. That always makes for an interesting discussion on how to approach the design, since everyone in the production process has his or her own approach and requirements. Perhaps the three most important are nutritionist requirements, production requirements, and (of course) commercial requirements.
Nutritionists need a wide variety of raw materials to be available 24/7 to dose a large selection of recipes automatically – of course with minimum manual interferences and maximum accuracy. This allows the nutritionist to produce specialized formulas without manual dosing, and a lot of different materials readily available.
Developments in nutritional science are producing more efficient compound feed and feed additives (premixes). They are also however increasing the demand for faster, more accurate and cleaner dosing, transport and mixing equipment. Generally speaking, there are nowadays more ingredients and often small doses.
Process requirements depend strongly on the type of production facility. Whereas a compound feed facility may focus on output and efficiency, a dedicated premix facility might focus on maximum flexibility in exotic or customer-specific premix production to serve demanding (niche) markets. This may allow longer batch times, but require more ingredients per dosing installation, and the ability to dose small and large components from a single silo. Flow characteristics of ingredients are often poor, and hygroscopic materials need to be treated carefully. This indicates different design parameters for storage and dosing equipment.
Many larger compound feed facilities are adding a dedicated premix line, bringing the supply of the most popular premixes in house. That not only shortens lead time, it also provides a significant economic advantage. Depending on demand, in-house production can also dose in-line, dosing the various additives directly into the mixer. Some plants find it more efficient to create larger quantities of premixed additives and carriers in one go. Doing so allows larger dosing sizes, and the production of premix when time is available. Additional storage might here be a problem, but again each different process and facility will have to prove which way works best.
What your design will need to consider
Studying the process will tell you the best equipment and batch size for a specific project. You can gain insight by analyzing the required production capacity for each of a selection of representative recipes. This can be a complex calculation, though. Process related variables include number of ingredients, batch cycle times, collection and internal transport times, and mixing times. Broader considerations include working hours, physical space, seasonal production peaks, and available budget.
Once you’ve decided on the key process equipment and how to set up the process itself, next is to fit all equipment within the available footprint and height. In existing buildings, adding or extending production lines is often a challenge and needs creative design by experienced process engineers.
And commercial requirements
Commercial requirements include delivering a range of products with as short a lead time as possible, with low capital and operating costs, and without compromising quality. In our experience, the best starting points for a process design or redesign are a thorough analysis of (realistic) wishes, with a good balance of nice-to-have features and future-proof design. Don’t overdo the nice-to-have and future-proof parts, though. The optional extras might tick all the boxes, but not fit the budget.
Author: Tim Broeke – Project Sales Engineer