What is the advantages to avoid gate valves on outlets?

1. When the gate valve is closed there will always gather material between the gate valve plate and the U-trough
2. Using a concept with reversible screw conveyors ensures that you can empty the screw conveyor and increase the hygienic level
3. Over time gate valves have a tedency to leak material – this is problematic in clean areas/hygienic areas

BEMA have years of experience in designing and manufacturing U-trough screw conveyors for the food industry. See another example of a powder distribution system without gate valves

What are the characteristics for U-trough screw conveyors?

1. The design of the U-through is a simple and economical design that resembles the “U”
2. The construction consists of a U-shaped structure that is relatively stiff and ensure that the complete screw conveyor is self carried
3. U-trough screw conveyors can handle a wide range of materials and are very often used for handling bulk material

Key issues to consider when designing screw conveyors for food the food indstry

1. Aviod areas where the material can collect – dead areas
2. Use correct material overall
3. Ensure all connections are 100% fully welded
4. Clean the weldings afterwards by acid pickling

FAQ – U‑trough Screw Conveyors for Powder

1. Purpose of U‑trough screw conveyors

U‑trough screw conveyors are designed for efficient powder transport in the food and process industry. They ensure controlled distribution of material from one inlet to multiple outlets while maintaining high hygiene standards in accordance with EC‑1935/2004 requirements .

2. How material distribution is achieved

The system distributes powder from one inlet to four outlets without using gate valves. This is accomplished by using three reversible screw conveyors that direct the flow precisely and maintain a stable, predictable material movement through the system .

3. Why gate valves are avoided

Gate valves tend to accumulate material between the valve plate and the U‑trough, which reduces hygiene and increases cleaning needs. Over time, gate valves may also leak, making them unsuitable for clean or hygienic production areas. Reversible screw conveyors eliminate these issues and allow complete emptying of the trough .

4. When a guide plate is relevant

A hygienically designed manual guide plate is used when the material flow is high and the density is low. In such cases, the powder behaves fluidically, and the guide plate prevents unintended flow toward the wrong outlet, ensuring accurate distribution .

5. Key characteristics of U‑trough screw conveyors

The U‑shaped construction is simple, economical and self‑supporting. It handles a wide range of bulk materials and is widely used in food industry applications. Proper design focuses on avoiding dead zones, using correct materials, fully welded connections and post‑weld acid pickling for optimal hygiene .