SPIRAC’s shaftless screw conveyors provide reliable, low-maintenance conveying of sludge, screenings, grit and other difficult-to-handle materials. Designed for municipal wastewater treatment plants, industrial facilities and solids handling applications, our shaftless spiral conveyor systems deliver superior performance, higher fill rates and reduced operating costs compared to conventional screw conveyors.
What Is a Shaftless Spiral (Screw) Conveyor?
A shaftless spiral (screw) conveyor uses a heavy-duty spiral without a central shaft to transport bulk materials efficiently. This unique design provides increased conveying capacity and allows sticky, stringy, viscous and abrasive materials to move freely through the system.
SPIRAC pioneered shaftless spiral (screw) conveying technology and continues to provide customised conveying solutions for wastewater treatment, industrial processing and solids handling facilities worldwide.
By eliminating the centre shaft and internal bearings, SPIRAC shaftless screw conveyors minimise blockages, reduce wear and maximise operational reliability in demanding environments.
Shaftless Screw Conveyor Benefits
SPIRAC shaftless screw conveyors offer numerous advantages over traditional screw conveyor systems:
- No centre shaft to restrict material flow
- No intermediate or end bearings within the conveyed material
- Higher filling rates
- Reduced wear and maintenance
- Lower operating costs
- Improved energy efficiency
- Reliable handling of difficult materials
- Long service life
- Customisable design options
The shaftless spiral design enables lower operating speeds while maintaining performance, resulting in less downtime and reduced maintenance requirements.
SPIROLINE® Horizontal and Inclined Conveyors
SPIROLINE® shaftless screw conveyor is designed for horizontal and inclined conveying via a U-trough configuration.
Suitable Applications
- Wastewater screenings handling
- Sludge transport
- Grit conveying
- Industrial solids handling
- Food waste processing
SPIROLINE® systems can be configured for conveying inclines of up to 30 degrees while maintaining efficient material transport.
SPIROLIFT® Vertical Conveyors
SPIROLIFT® shaftless screw conveyors are designed for vertical and steep incline conveying using an OK-trough design.
Ideal For
- Vertical sludge transport
- Screenings lifting
- Grit handling systems
- Confined plant layouts
SPIROLIFT® systems are suitable for conveying applications above 30 degrees where space is limited and vertical transport is required.
Designed for Difficult-to-Handle Materials
SPIRAC shaftless screw conveyors are specifically engineered to transport materials that traditionally cause problems for conventional conveying systems.
Typical materials include:
- Municipal dewatered sludge
- Wastewater screenings
- Grit and sand
- Industrial sludges
- Organic waste
- Viscous materials
- Sticky products
- Stringy and fibrous materials
The open-centre shaftless design significantly reduces the risk of clogging and material build-up.
Premium Swedish Steel Spirals
SPIRAC shaftless spirals are manufactured from high-strength Swedish steel specifically selected for its superior mechanical properties and tensile strength.
The robust construction provides:
- Increased torque capacity
- Reduced wear
- Longer service life
- Improved operational reliability
This makes SPIRAC shaftless screw conveyors particularly suitable for harsh wastewater and industrial environments.
Customised Shaftless Spiral (Screw) Conveyor Solutions
Every application is different. SPIRAC offers a wide range of spiral diameters, pitches, cross-sections and trough configurations to match specific throughput, torque and material characteristics.
Single Section Spirals
Single section spirals are ideal for:
- Horizontal conveying
- Short conveying distances
- Lower torque applications
- Sludge handling
- Screenings transport
Welded Insert Spirals
For greater efficiency and strength, SPIRAC offers spirals with welded inserts that:
- Reduce material fallback
- Increase conveying performance
- Improve inclined transport
- Enhance handling of sticky materials
For lime-treated sludge and similar products prone to build-up, spirals with inserts and scraping edges may be recommended.
Applications for Shaftless Spiral (Screw) Conveyors
SPIRAC shaftless screw conveyors are widely used across a range of industries.
Municipal Wastewater Treatment
- Sludge handling
- Screenings transport
- Grit conveying
- Biosolids management
Industrial Wastewater Treatment
- Industrial sludge handling
- Process waste transport
- Solids conveying
Food and Beverage Processing
- Organic waste transport
- By-product handling
- Residuals conveying
Pulp and Paper
- Fibre residual handling
- Process waste transport
- Sludge movement
