Cooling Screw Conveyor
A cooling screw conveyor takes hot product off a kiln, furnace, dryer, fluidized bed or reactor and brings it down to a safe handling temperature while it moves. Cooling water or another coolant flows through hollow flights, the shaft and a jacketed trough. The coolant never touches the product, so the screw cooler suits processes that need strict separation, including food and chemical applications.
Typical materials include bottom ash and fly ash, lime, clay, calcined petroleum coke, carbon black, metal oxides, cement raw meal, plastics, salts, biochar, pyrolysis residues and pastes. Inlet temperatures can reach about 2,190°F (1,200°C). Every product-contact surface is actively cooled, which protects the steel and extends service life.
Screw coolers can discharge directly from a fluidized bed, or be arranged in a cascade of several units to cool large mass flows gently and in stages.
Cooling Screw Conveyors - Benefits
A cooling screw conveyor combines continuous conveying and controlled cooling in one compact system. It cools hot bulk materials efficiently, handles them gently, and keeps the coolant safely separated from the product.
High Cooling Efficiency −
Actively cooled surfaces give high heat transfer and fast temperature reduction in a compact unit.
Gentle Material Handling +
Combined Cooling and Conveying +
Reliable Temperature Control +
Suitable for High-Temperature Materials +
Low Maintenance and Long Service Life +
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Contact us todayCooling Screw Conveyor - Features
The cooling screw conveyor circulates coolant through hollow screw flights to maximize heat transfer while conveying. Shaft design, trough shape and options are engineered for each application.
- Hollow Flight CoolingHollow screw flights for efficient cooling.
- Single or Multi-Shaft DesignSized for a wide range of cooling duties and materials.
- Safe Cooling Medium SeparationCoolant fully separated from the product.
- Self-Cleaning OptionReduces buildup of sticky materials.
- Multiple Trough DesignsPipe, U-trough and custom trough configurations.
- Custom Cooling IntegrationOptional piping, valves, insulation and temperature monitoring.
Hollow-Flight Screw Cooler Design
A standard jacketed screw exchanges heat only through the trough and the shaft tube. Our hollow-flight principle also cools through the flights, which are in constant contact with the product. That gives much higher power density, so a smaller cooler can do the same duty, and larger duties become practical.
Self-Cleaning Option for Sticky Materials
Some products stick or bridge and form an insulating layer on the flights. Our self-cleaning twin-shaft design closes the gap between intermeshing flights and creates high relative speed between the shaft surfaces. Built-up material is scraped away continuously and cooling performance stays steady.
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Our experts can help you select the right cooling screw conveyor solution for your material and production requirements.
Trough Shapes and Configurations
Coolers are available with pipe, U, ω and double-ω troughs and with one or more shafts, so the geometry can match fill level, throughput and residence time. Upstream, the cooler pairs with a heating screw conveyor or kiln. Downstream, it feeds a screw conveyor, bucket elevator or bagging line.
Sizing a Cooling Screw Conveyor
For a quote, send us the throughput in lb/h or tons/h, inlet and target outlet temperatures in °F, bulk density, particle size and the coolant available. We calculate the required heat transfer area and propose the shaft and trough layout.
Frequently Asked Questions
A cooling screw conveyor is a thermal processing machine that conveys and cools bulk material at the same time. It uses indirect heat transfer through cooled hollow flights, shaft and trough.
Coolant, usually water or a thermal fluid, circulates inside the hollow flights and shaft. Heat moves from the hot product through the steel surfaces into the coolant while the screw keeps the material moving.
Common materials include fly ash and bottom ash, lime, clay, cement raw meal, calcined coke, carbon black, activated carbon, metal oxides, salts, plastics, biochar, sludges and other hot powders or granules.
Benefits include efficient cooling, gentle handling, a compact footprint, continuous operation and full separation of coolant and product. Controlled cooling also protects downstream conveyors, silos and packaging.
A hollow-flight cooling screw conveyor has internal channels in the flights for coolant. Since the flights stay in constant contact with the product, they provide a large cooling surface and high performance.
A self-cleaning cooling screw conveyor uses two intermeshing shafts with very small clearance. The relative motion scrapes product off the flights, so sticky or adhesive materials do not insulate the cooling surfaces.
Use a self-cleaning design for sludges, pastes, sticky powders and any product that forms a layer on cooling surfaces. It keeps cooling stable and cuts cleaning downtime.
Screw coolers are common in coal and biomass power plants, cement and lime plants, chemical processing, waste-to-energy, battery recycling, plastics and mineral processing.
The range depends on the product and process. High-temperature designs can accept material at about 2,190°F (1,200°C) and discharge it at a temperature that is safe for conveying, storage or packaging.
