Bin discharger with double extraction screws

Bin discharger with double extraction screws designed and manufactured in accordance with EC-1935/2004 (the food directive). The bin is manufactured with a mixing screw rotor inside the bin. The double extraction screws delivers the material to a screw pump. The extractions screws are separated via a gear box that ensures that they run in intersection.

The design has taken hygienic issues into consideration. Whereever possible horizontal surfaces are avoided to ensure that cleaning water can easily drain off. BEMA has over the years gained experience in designing applications for the food industry. It requires skilled engineering capabilities to ensure workable hygienic designs of screws for food applications.

Issues to consider when designing a bin with a screw conveyor for the food industry

1. Ensure that it is as easy to clean as possible
2. Define the level of surface treatment of steel in contact with the material
3. Ensure that all material in contact with the food is in accordance with EC-1935/2004
4. Define the level of documentation you want for your application

BEMA has a design department that can assist you in selecting the right level for your application. Always keep in mind that surface treatment is expensive and can become more and more expensive when you increase your demands. We recoomend you to be critical from the beginning for the design with respect to surface treatment. Hygienic surfaces is not only a discussion of small Ra values. In most of the cases 2B colled rolled plates, TIG welding and acid pickling is enough. See similar examples of screw conveyors for food application

FAQ: Bin Discharger with Double Extraction Screws

1. What is a bin discharger with double extraction screws used for?

This solution is designed for controlled storage, mixing, and extraction of food materials. The integrated mixing screw ensures uniform material consistency inside the bin, while the two extraction screws deliver the product directly to a screw pump for continuous downstream processing.

2. How do the double extraction screws operate?

The two extraction screws are mechanically separated by a gearbox that ensures they run in intersection. This synchronized movement prevents material buildup, improves flow stability, and supports accurate dosing into the pump. The system is delivered on a frame with a wheel station for the pumping unit, making installation efficient.

3. What hygienic design features are included?

The bin is engineered according to EC‑1935/2004 food‑contact requirements. Horizontal surfaces are avoided wherever possible to ensure water drains easily during cleaning. Surfaces in contact with food are carefully selected, typically using 2B cold‑rolled plates, TIG welding, and acid pickling to achieve a hygienic and easy‑to‑clean finish.

4. What should be considered when designing screw‑based food equipment?

Key considerations include defining the required surface treatment level, ensuring all contact materials comply with food regulations, and determining the necessary documentation. BEMA’s engineering team assists in selecting the right design level while balancing hygiene, durability, and cost.