U-Type Screw Conveyor for Feed Mills

In feed mill applications, U-type screw conveyors are used for cracked grain, bran, premix, flour, granules, pellets and similar bulk materials. The final design should always match the product characteristics, required capacity and plant layout.

What Is a U-Type Screw Conveyor?

A U-type screw conveyor transfers powder, granule or small-particle bulk materials from one process point to another. The system generally consists of a U-shaped trough body, screw flight, shaft, drive unit, inlet, outlet and removable or hinged covers.

Because the product moves inside a covered trough, the line stays cleaner than open transfer points. This makes U-type screw conveyors practical for controlled feeding, intermediate transfer and short to medium-distance conveying applications.

Where Is a U-Type Screw Conveyor Used?

U-type screw conveyors can be installed under or between different equipment in a production line. They are commonly used below mixers, hoppers, silos, crushers, dosing units and packaging systems.

In silo discharge applications, a U-type screw conveyor helps control material flow from the bottom of the silo or bin to the next process stage. In mixer discharge lines, it can support controlled transfer after the batch is completed.

Typical applications include:

• Feed mill conveying systems
• Silo discharge lines
• Mixer discharge lines
• Premix and additive handling
• Grain, flour and bran transfer
• Granule and pellet conveying
• Horizontal or low-incline material transfer
• Dosing and controlled feeding points

Key Advantages of U-Trough Screw Conveyors

U-type screw conveyors are preferred where controlled transfer, practical access and compact installation are important. Their U-shaped body allows easier inspection and cleaning compared with fully tubular conveyor designs.

Main advantages include:

• Controlled transfer of powders, granules and bulk materials
• Covered structure to help reduce dust and product spillage
• Multiple inlet and outlet options where required
• Compact installation in narrow production areas
• Practical access for cleaning, inspection and maintenance
• Easy integration with silos, mixers, hoppers and packaging lines

For production lines that handle different recipes, premix materials or additives, cleaning access is especially important. Removable or hinged covers make it easier to inspect the screw and clean the conveyor body when required.

Screw Flight Options

Screw flight selection should not be based only on the product name. Density, moisture level, flow behaviour, abrasiveness, stickiness and particle size all affect the correct design.

Full Flight Screw

A full flight screw is commonly used for wheat, barley, corn, flour, premix and fine granule products. It provides continuous and stable material flow in many standard conveying applications.

Ribbon Flight Screw

A ribbon flight screw can be preferred for sticky, moist or lump-forming products. Its open structure may help reduce material build-up around the centre shaft.

Paddle Screw

A paddle screw can be used when light mixing is required during conveying. It may be preferred in premix and additive handling lines depending on the process.

Cut Flight Screw

A cut flight screw can be used for products with a higher risk of bridging, compaction or irregular flow. It can create a light mixing and aeration effect during transfer.

Shaftless Screw

A shaftless screw may be considered for fibrous, sticky or wrapping-prone materials. Since there is no centre shaft, the risk of blockage can be reduced in suitable applications.

U-Type Screw Conveyor vs Tubular Screw Conveyor

U-type screw conveyors and tubular screw conveyors both transfer bulk materials, but their body structures are different.

A U-type screw conveyor has a U-shaped trough body with removable or hinged covers. This design offers easier access for cleaning, inspection and maintenance. It is often preferred in horizontal or low-incline lines where service access matters.

A tubular screw conveyor has a closed pipe body. It may be useful where a fully enclosed conveying route is required or where the system must fit into a compact sealed layout.

The right choice depends on product type, cleaning frequency, hygiene requirements, incline angle, capacity and plant layout.

U-Type Screw Conveyor vs Chain Conveyor

A U-type screw conveyor is generally used for short to medium-distance transfer, controlled feeding and dosing applications. It moves the product with a rotating screw flight inside a U-shaped trough.

A chain conveyor is usually preferred for longer horizontal transfer lines, silo discharge systems and higher-capacity enclosed conveying applications. It moves the product with chain-driven scraper flights inside a closed casing.

In many feed mill projects, both systems can be used in different parts of the same production line. The correct selection depends on product behaviour, transfer distance, required capacity and process layout.

Capacity and Design Criteria

The capacity of a U-type screw conveyor depends on several technical factors. Screw diameter, pitch, rotation speed, filling rate, product density, conveyor length and incline angle all affect the final result.

Important design criteria include:

• Product type and bulk density
• Required conveying capacity
• Conveyor length
• Incline requirement
• Inlet and outlet positions
• Screw diameter and pitch
• Rotation speed
• Product moisture and flow behaviour
• Abrasiveness and wear risk
• Cleaning and maintenance access
• Daily operating time

If these details are not evaluated correctly, the conveyor may experience irregular feeding, product build-up, excessive wear or capacity loss.

Kardev Project-Specific U-Type Screw Conveyor Solutions

Kardev designs and manufactures project-specific U-type screw conveyors for feed mills, grain processing plants, flour facilities, premix lines and bulk material handling applications.

Each conveyor is configured according to product type, required capacity, line length, incline, working conditions and plant layout. Screw flight type, body structure, cover design, drive arrangement, inlet position and discharge points are evaluated according to the needs of the production line.

Kardev U-type screw conveyor systems can be designed for:

• Horizontal and low-incline conveying
• Controlled material transfer
• Silo discharge applications
• Mixer discharge lines
• Premix and additive handling
• Grain, flour, bran and granule transfer
• Project-specific inlet and outlet positions
• Practical cleaning and maintenance access

For applications involving different recipes, premix materials or frequent cleaning, the U-type body design can offer a practical maintenance advantage.

FAQ

What products can a U-type screw conveyor carry?

A U-type screw conveyor can carry feed, grain, flour, bran, premix, granules, pellets and similar bulk materials. The final design should be selected according to product density, flow behaviour, moisture level and required capacity.

What is the difference between a U-type screw conveyor and a tubular screw conveyor?

A U-type screw conveyor has a U-shaped trough body with practical access for cleaning and maintenance. A tubular screw conveyor has a closed pipe body and may be preferred where a fully enclosed conveying route is required.

What factors affect U-type screw conveyor capacity?

Capacity is affected by screw diameter, pitch, rotation speed, product density, filling rate, conveyor length and incline angle. Product moisture, flow behaviour and daily operating time should also be considered.

Which screw flight type should be selected?

The screw flight type should be selected according to the product. Full flight screws are common for free-flowing materials, while ribbon, paddle, cut flight or shaftless designs may be preferred for sticky, moist, fibrous or mixing-related applications.

Can Kardev manufacture project-specific U-type screw conveyors?

Yes. Kardev can design and manufacture U-type screw conveyors according to product type, capacity requirement, line length, incline, inlet-outlet layout and process needs.

Request a Project-Specific U-Type Screw Conveyor Design

If you need a U-type screw conveyor for a feed mill, grain processing line, flour plant, premix system or bulk material handling application, the correct design should start with product and capacity data.

Kardev can evaluate your product type, line layout, required capacity, incline, inlet-outlet positions and cleaning requirements to design a suitable screw conveyor system for your production line.