Cooling Screw Conveyor
Cooling screw conveyors are used to chill a wide range of bulk materials and pasty media. For a variety of application areas and bulk material compositions, cooling screw conveyors with specialized features are offered on the market. Cooling screw conveyor is suitable for all applications in which not only cautious handling of the bulk product, but also rigorous separation of the cooling medium and the bulk product is necessary, such as in food processing. Cooling screw conveyors can be used to transport various materials such as coal bottom ash and fly ash, plastics, sewage sludge, salts, cyanide, metal oxides, cement raw meal, pyrolysis residues and pastes of various formulations.
The application and temperature range of the cooling screw conveyors extends up to 1,200°C. Through active cooling of all surfaces touched by the product, long service life and low material impact can be achieved.
There are hardly any limits to their use – direct removal from the fluidized bed is just as easy for our cooling screw conveyors as their use in cooler cascades to gently control the temperature of large volume and mass flow rates.
Cooling Screw Conveyors - Benefits
A Cooling Screw Conveyor combines continuous material conveying and controlled cooling in a single compact system. It provides efficient thermal treatment of hot bulk materials while maintaining gentle handling, reliable operation, and safe separation between the cooling medium and product.
High Cooling Efficiency −
Provides excellent heat transfer performance through active cooling surfaces, reducing product temperature effectively within a compact design.
Gentle Material Handling +
Combined Cooling and Conveying +
Reliable Temperature Control +
Suitable for High-Temperature Materials +
Reduced Maintenance and Long Service Life +
Cooling Screw Conveyor - Features
A Cooling Screw Conveyor combines continuous material conveying and controlled cooling in a single compact system. It provides efficient thermal treatment of hot bulk materials while maintaining gentle handling, reliable operation, and safe separation between the cooling medium and product.
- Hollow Flight CoolingHollow screw flights provide efficient cooling.
- Single or Multi-Shaft DesignAvailable for various cooling capacities and materials.
- Safe Cooling Medium SeparationPrevents contamination between product and cooling media.
- Self-Cleaning OptionReduces buildup of sticky materials.
- Multiple Trough DesignsAvailable in pipe, U-trough, and custom configurations.
- Custom Cooling IntegrationIncludes optional piping, valves, insulation, and temperature monitoring.
Technical specification of Cooling Screw Conveyor:
Operation temperatures
up to 1200°C
Shaft version
Single or multiple
Shaft design
Through-Shapes (Pipe Trough, U-Trough, ω-Trough, ωω-Trough)
Cooling Screw Conveyor or Screw cooler:
Due to their design, our screw heat exchangers differ from the standard models available on the market mainly due to the proven and tested hollow flight principle, which combines several advantages. The most outstanding advantage is the achievable power density-compared to energy transfer via shaft tube and trough (housing) only, the hollow flight principle achieves a far greater transfer performance.
This results in higher efficiency, or rather a smaller machine is required for a specific output and applications within higher output ranges are made possible by the hollow flight principle.
As some bulk products tend to form adhesions and tend to be bridging, they often build an insulating layer on the hollow flights.
Depending on the condition of your bulk product, sludge or paste, the self-cleaning provides a proven, reliable option for the screw heat exchanger, which ensures uniformly clean hollow flight surfaces. As these constitute the main surfaces for heat transfer, efficient operation can thus be ensured.
By using a special geometry, the gap in-between the hollow flights is nearly eliminated and a high relative speed is generated between the surfaces of the screw shafts. This in turn has a cleaning effect; it removes adhering bulk materials and results in greater efficiency. Only our self-cleaning technology allows the use of when processing adhesive and pasty bulk materials.
To achieve the above-named properties, the specially designed shafts are operated with equidirectional rotation, a speed ratio of 2:1 (shaft 1 to shaft 2) and relatively small spacings.
Available trough-shapes of cooling screw conveyors include Pipe trough, U-trough, ω-trough and ωω-trough .
Frequently Asked Questions
A Cooling Screw Conveyor is a thermal processing system that simultaneously conveys and cools bulk materials during transportation. It uses indirect heat transfer through cooled screw flights and shafts to reduce product temperature while maintaining a compact and efficient design.
A Cooling Screw Conveyor uses hollow screw flights and/or shafts where a cooling medium, such as water, thermal oil, or another coolant, circulates. Heat is transferred from the hot material through the screw surfaces to the cooling medium while the product is continuously conveyed.
Cooling Screw Conveyors are suitable for a wide range of bulk materials, including ashes, cement raw materials, pyrolysis residues, salts, plastics, activated carbon, metal oxides, sludges, and other high-temperature powders or granules.
A Cooling Screw Conveyor provides efficient cooling, gentle product handling, compact installation, continuous operation, and reliable separation between the cooling medium and the conveyed material. It can also reduce product degradation and improve downstream process performance.
A Hollow Flight Cooling Screw Conveyor uses specially designed screw flights with internal channels for coolant circulation. Since the flights are continuously in contact with the product, they provide a large heat transfer surface and efficient cooling performance.
A Self-Cleaning Cooling Screw Conveyor is designed for sticky, adhesive, or difficult-to-handle materials that may build up on cooling surfaces. The special twin-shaft design creates a cleaning effect by removing product buildup from the screw flights, maintaining efficient heat transfer.
A Self-Cleaning Cooling Screw Conveyor is recommended when processing materials such as sludges, pastes, sticky powders, or products that tend to form insulating layers on cooling surfaces. The self-cleaning mechanism helps maintain stable cooling performance and reduces maintenance requirements.
Cooling Screw Conveyors are widely used in industries such as aluminum, cement, chemical processing, energy, waste treatment, plastics, and mineral processing where controlled cooling of bulk solids is required.
The operating temperature range depends on the material and process conditions. Advanced Cooling Screw Conveyors can be designed for high-temperature applications, including cooling bulk materials from temperatures up to approximately 1,200°C.
