Screw conveyor

IFAMAC screw conveyors transport bulk solids with a moderate particle size continuously and under controlled conditions. A rotating screw installed inside a trough or casing moves the material from the infeed point to the discharge.

These machines can be used to convey aggregates, fine biomass, ash, coal and other materials compatible with this system. Each conveyor is designed according to the product properties, required capacity, route length and operating conditions.

IFAMAC manufactures screw conveyors in carbon steel or stainless steel and can incorporate cooling jackets around the casing and shaft when required by the process temperature.

Continuous conveying by screw

The material enters the conveyor through an inlet and comes into contact with the screw. Its rotating movement progressively moves the product through the casing towards the discharge point.

The rotational speed, diameter, pitch and screw geometry are selected according to the required capacity and the material’s behaviour.

This configuration maintains a regular flow and, when a closed casing is used, reduces the product’s exposure to the surrounding environment.

Applications involving solids with a moderate particle size

Screw conveyors can handle solid products whose particle size and behaviour are compatible with transportation by a rotating screw.

Possible applications include the transportation of:

• Aggregates and minerals.
• Fine biomass.
• Ash.
• Coal.
• Powders and granular materials.
• Other bulk solids with a moderate particle size.

Compatibility must be determined by considering particle size, moisture content, density, abrasiveness, temperature and the material’s tendency to compact or adhere.

Configuration adapted to the material

IFAMAC determines the conveyor diameter, screw pitch, speed, power and length according to the requirements of each process.

The design also takes into account the route inclination, filling level, number of intermediate supports and characteristics of the inlet and discharge points.

Components exposed to contact and wear are selected according to the material’s abrasiveness and operating conditions.

Carbon-steel or stainless-steel construction

The conveyors can be manufactured in carbon steel or stainless steel, depending on the material, working environment and installation requirements.

Carbon steel can be used for general industrial applications, while stainless steel is suitable when greater corrosion resistance or specific cleaning and product-compatibility conditions are required.

The material grade, thickness and finish are determined individually for each project.

Conveying inside an enclosed casing

The screw can be installed inside a covered trough or an enclosed tubular casing, depending on the process requirements.

An enclosed configuration helps contain the material, reduce dust emissions and protect the product from the external environment.

Covers, inspection openings and access points are designed according to the installation’s inspection, cleaning and maintenance requirements.

Optional cooling jackets

When the process handles products at elevated temperatures or requires thermal conditions to be controlled during transportation, the equipment can incorporate cooling jackets.

Cooling can be applied to the outer casing and, where technically feasible, to the screw shaft.

The system is sized according to the inlet temperature, flow rate, residence time and thermal properties of the material.

One or more inlet and discharge points

The conveyor can be configured with several inlets and outlets to collect or distribute material at different points in the process.

This makes it easier to integrate the conveyor beneath hoppers, silos, filters, preparation equipment and other systems that need to discharge or distribute bulk solids.

The position and dimensions of each connection are determined according to the required capacity and plant layout.

Difference between a screw conveyor and a screw feeder

The main purpose of a screw conveyor is to transport material between different points in an installation.

A screw feeder, by contrast, is designed to extract and meter a controlled quantity of product from a hopper or storage vessel. Its operation must regulate the flow supplied to the downstream equipment.

Although both systems use a rotating screw, their sizing and configuration must correspond to the specific function they perform within the process.

Integration with bulk-material handling systems

Screw conveyors can be integrated with hoppers, silos, feeders, screens, mills, filters, conveyors and other process equipment.

Sensors and the control system coordinate feeding, speed and discharge to maintain operation in line with the installation’s capacity.

The equipment can be incorporated into both new plants and existing bulk-solid conveying systems.

Custom design and manufacture

IFAMAC adapts the length, diameter, screw, drive, construction materials and connection points to the requirements of each project.

The design takes into account the available space, maintenance access, structural loads and communication with upstream and downstream equipment.

Each solution is developed based on an analysis of the material and the actual operating conditions.