Tolva

A tolva, known in English as a hopper, is a storage container with a funnel-shaped body that holds bulk materials and releases them by gravity into a downstream process. Tolvas are used in agriculture, mining, manufacturing, cement, plastics, and food processing to store and meter items such as grain, sand, cement powder, plastic pellets, and other granules.

Most tolvas feature an outlet at the base and a discharge mechanism, such as a gate, slide, rotary valve, or feeder, to control flow. The interior bottom profile determines whether the material flows in a mass flow fashion or funnel flow, and some designs aim to prevent arching or ratholing. Designers consider the material’s bulk density, angle of repose, moisture, and flowability when selecting size and outlet geometry.

Common construction materials include carbon steel and stainless steel, with coatings or linings for wear resistance or hygienic applications. For food or pharmaceutical use, hygienic design and cleanability are essential. Hoppers may be insulated for temperature-sensitive materials and can be integrated with conveyors, silos, or feeders to form part of a larger material-handling system.

Operation and safety considerations include preventing bridging and blockages, using vibration or agitators as needed, and implementing dust control to reduce explosion risk. Regular inspection, cleaning, and compliance with relevant standards (for example, food safety or occupational safety guidelines) are recommended to maintain performance and safety.