Optimizing Powder Handling with Customized Flexible Screw Conveyors
Flexible screw conveyors are widely used in industrial and manufacturing sectors for material handling, particularly in the transportation of powders. Their popularity stems from their simplicity, low cost, and flexibility. While these conveyors offer a reliable solution for handling various materials, including powders, their design must be tailored to meet specific operational and material characteristics.
Why Customization Matters
Flexible screw conveyors can be customized to address the unique challenges posed by different materials. The performance of a conveyor is influenced by factors such as material size, shape, weight, moisture content, and environmental conditions. These variables affect how effectively a conveyor can move materials, which is why a one-size-fits-all solution rarely works. Customization of key components like the screw itself, hopper design, and motor speed is crucial for optimal performance.
Key Customizable Features for Powder Handling
- Screw Design
- Flat Wire Augers: Ideal for light materials, flat wire augers provide a positive forward force while reducing outward pressure against the tube walls, enhancing efficiency and minimizing material degradation.
- Beveled Wire Augers: These are effective for powders that tend to build up on surfaces (e.g., TiO₂ and other oxides), preventing material buildup and ensuring smooth operation.
- Center Cores: For dense or fluidized powders, a center core reduces the available space within the screw, easing the load and improving conveyance efficiency.
- Hopper Designs
- Vibratory Hoppers: These promote consistent material flow and eliminate bridging in the hopper. They come in both standard and custom sizes and are available in stainless steel for enhanced durability.
- Hopper-Mounted Air Pads: Air pads fluidize the material, making it easier to move and preventing blockages.
- Mobile Bases
- Optional mobile bases enable flexible screw conveyors to be relocated within a plant, reducing equipment redundancy and capital costs. These bases provide discharge heights up to 12 ft (3.66 m), making them versatile for different production areas.
- Agitation and Flow Promotion
- Ribbon and Pin Agitators promote the flow of sluggish or high-moisture powders, ensuring smooth transport and avoiding blockages in the hopper.
Operational Considerations for Maximum Efficiency
- Running Conditions
Flexible screw conveyors should not be operated empty for extended periods, as this can cause excessive wear. Sensors can be installed at the pickup point to automatically shut off the conveyor when no material is present, preventing unnecessary strain on the system. - Dry Operations
When the conveyor is running at high fill percentages and then runs dry, slippage and a decrease in output can occur. To address this, conveyors should be designed with the appropriate outer tube and screw configuration, along with slower RPM settings to maintain material flow even when the hopper is nearly empty. - Hi/Lo and Tilt-Style Conveyors
Hi/Lo conveyors are ideal for operations where total evacuation of materials is critical. They allow operators to easily adjust the conveyor’s angle for cleaning or maintenance without the need for lifts or ladders. This feature simplifies washdowns, cleanouts, and auger changes. - Batch, Intermittent, and Continuous Operations
- Batch Operation: This method is straightforward and effective when dealing with one material at a time. For minimal loss, batch processing should start with the largest ingredients and gradually introduce smaller components.
- Intermittent Operation: For processes that require frequent starts and stops, special modifications can be made to strengthen the conveyor and ensure smooth startup, even with heavy materials.
- Continuous Operation: Conveyors designed for continuous operation should be sized and engineered to run efficiently over long periods.
Maintenance and Residual Product Removal
Even with customized components, flexible screw conveyors will leave some residual material in the inlet tube once the hopper is empty. Quick evacuation is possible by removing the end cleanout cap and reversing the screw. For further cleaning, air, water, or solvents can be used. In more demanding applications, the outer tube and screw can be removed and cleaned thoroughly.
Preventive Maintenance (PPM)
A well-planned preventive maintenance schedule is essential to ensure reliable operation and maximize the conveyor’s lifespan. Regular checks and cleaning reduce wear and prevent performance issues, ensuring desired production levels are maintained.
Conclusion
Customization is key to optimizing the performance of flexible screw conveyors in powder handling applications. From screw design to hopper configuration and mobile options, selecting the right features for specific material handling needs can significantly improve efficiency and reduce operational costs. By working with an experienced equipment provider, manufacturers can ensure their conveyor systems meet all operational demands while maximizing productivity and profitability.