Live Bottom Screw Conveyor | Anti-Bridging Multi-Screw Bin Discharger
A live bottom screw conveyor is a heavy-duty multi-screw extraction unit mounted beneath bunkers, silos and storage hoppers. A bank of parallel, synchronised screws forms an active live bottom to extract bulk solids evenly across the full bin width, rather than drawing material only from a single outlet point. This design removes dead zones and stops common issues such as bridging, arching and ratholing for sticky, compressible and stringy materials. We supply both shafted and shaftless live bottom screw feeders fitted with wear-resistant liners, suitable for continuous 24-hour operation in waste-to-energy, biomass and pulp processing lines. Variable speed drive delivers stable volumetric feeding to match downstream process throughput.
Working Principle The live bottom screw conveyor relies on a set of parallel screws running in synchronous rotation at the base of the storage bin. Instead of pulling material locally at one discharge opening, the rotating screws mobilise the entire material bed across the full bin width. This uniform extraction breaks up material arches and prevents bridging and ratholing, which frequently occur with cohesive, compressible bulk solids like sludge, RDF and wet biomass. By adjusting the screw rotating speed via variable frequency drive, the system achieves accurate volumetric feeding and feeds material steadily to downstream conveying or processing equipment.
H2: Key Advantages
- Effective anti-bridging and anti-ratholing performance for sticky, compressible and tangled bulk materials
- Full-width uniform material extraction without dead zones inside the bunker
- Optional shafted or shaftless screw configuration to suit different material characteristics
- Heavy-duty construction designed for 24/7 continuous operation in harsh industrial environments
- Wear-resistant liner protection for long service life when handling abrasive materials
- Stable volumetric feeding with adjustable throughput by variable speed control
- Compact layout for easy integration under bunkers, silos and hoppers
- Lower maintenance demand compared with other mechanical bin discharge devices
Typical Applications Our live bottom screw conveyor is widely deployed for difficult bulk solids in the following industries:
- Waste-to-energy (WtE) plants: municipal solid waste (MSW), RDF / refuse derived fuel
- Biomass power stations: wood chips, bark, straw and agricultural residues
- Sludge treatment facilities: dewatered sludge, filter cake
- Pulp and paper mills: bark, pulp rejects and process sludge
- Recycling & composting plants: organic waste, plastic flake, light fraction waste
- Anaerobic digestion projects: green waste, organic feedstock
H2: Optional Configurations
- Shafted screw / shaftless screw version selection
- Hardened wear liners for abrasive materials
- Variable speed drive (VSD) for adjustable feeding rate
- Different material options: carbon steel, 304 / 316L stainless steel
- Sealed housing for odour containment
- Safety guards, access covers and inspection ports
FAQ
Q: What is a live bottom screw conveyor? A live bottom screw conveyor is a multi-screw bin discharger installed under bunkers. Synchronised parallel screws extract material evenly over the full bin width to avoid bridging and ratholing for cohesive bulk solids.
Q: What is the difference between a live bottom screw conveyor and a standard silo screw conveyor? A standard silo screw only draws material at a single outlet point. The live bottom design mobilises the whole material bed across the bin width, which is critical for sticky, compressible materials prone to arching.
Q: Shafted or shaftless live bottom screw, which should I pick? Choose shafted screws for free-flowing or abrasive materials. Shaftless screws work better for stringy, tangled materials such as wet fibres, sludge and long organic waste.
Q: Can live bottom screw conveyors run continuously? Yes. Our heavy-duty live bottom screw feeders are engineered for 24/7 continuous operation in harsh industrial processing lines.
Q: What bulk materials are not suitable for live bottom screw conveyors? Large, hard lumps with excessive size may cause jamming. Contact us to check material properties for custom selection.
SELECTION & TECHNICAL QUESTIONS
Q1: How do I select the right conveyor model? What information should I provide?
> To recommend the most suitable solution, please provide the following details:
> 1. Material type: What material are you conveying? (e.g., fly ash, wood chips, biomass pellets, bottom ash, etc.)
> 2. Material properties: Particle size, temperature, moisture content, abrasiveness
> 3. Capacity requirement: How many tons per hour (t/h) do you need?
> 4. Installation conditions: Conveying distance, incline angle, space limitations
> 5. Application industry: Which industry is this for? (e.g., waste-to-energy plant, biomass power plant, cement plant)
> You can also email us or contact us via WhatsApp. Our engineers will get back to you within 24 hours.
Q2: What is the difference between screw conveyors and chain conveyors? Which one should I choose?
> Both types have different applications:
> – Screw Conveyors: Best for powdery and small-grain materials (e.g., fly ash, cement powder). Good sealing performance, simple structure, low maintenance cost.
> – Chain Scraper Conveyors: Best for bulky, highly abrasive materials (e.g., bottom ash, municipal solid waste, biomass fragments). Supports multiple inlet and outlet points.
> – Bucket Elevators: Ideal for vertical or steep-incline material lifting.
> If you are not sure, tell us your material and working conditions, and our engineers will help you choose.
Q3: Can your equipment handle high-temperature materials? What is the maximum temperature?
> We can customize equipment according to material temperature:
> – Standard type: 0~80°C, carbon steel
> – Medium temperature type: 80~200°C, thickened wear-resistant liner
> – High temperature type: 200~400°C, special heat-resistant steel, optional cooling jacket
> Please tell us your material temperature, and we will recommend the most suitable material solution.
Q4: Are there any limits on conveying distance and lifting height?
> Standard design range:
> – Screw conveyor: Single section up to 70 meters; multiple sections can be connected for longer distances
> – Chain conveyor: Single machine up to 60 meters
> – Bucket elevator: Lifting height up to 50 meters
> We can also customize for extra-long distances or special angles. Contact us for detailed solutions.
Q5: Do you provide explosion-proof design?
> Yes. For explosive and flammable conditions such as pulverized coal and biomass dust, we offer:
> – Explosion-proof motors (Ex d IIB T4 standard)
> – Reserved openings for explosion vents / rupture discs
> – Fully sealed structure to prevent dust leakage
> Please specify your explosion-proof rating requirements.
CUSTOMIZATION & MANUFACTURING
Q6: Do you support customization? What is the lead time?
> Over 90% of our equipment is customized according to customer working conditions. Standard models take about 90–120days. Special customizations take 120–180 days, depending on configuration complexity.
Q7: What material options do you offer?
> Common materials include:
> – Carbon steel (Q235B): Standard working conditions
> – Wear-resistant steel (NM400/NM500): Highly abrasive materials
> – Stainless steel 304/316L: Food, chemical, corrosion-resistant requirements
> – Bi-metal wear-resistant composite plate: Extreme abrasion conditions
> We will recommend the most cost-effective material solution based on your material properties.
Q8: What certifications do you have?
> We hold the following certifications:
> – ISO 9001:2015 Quality Management System
> – ISO 14001 Environmental Management System
> – ISO 45001 Occupational Health & Safety Management
> – CE Certification (EN 1090 Steel Structure)
> If you need scanned copies of specific certificates, please contact us.
DELIVERY & LOGISTICS
Q9: Which countries do you export to? Do you have export experience?
> Our equipment has been exported to more than 20 countries worldwide, including:
> – Europe: Germany, France, Poland, Turkey, etc.
> – Southeast Asia: Singapore, Thailand, Indonesia, Vietnam, etc.
> – Middle East: Saudi Arabia, UAE, etc.
> – South America**: Brazil, Chile, etc.
> We are familiar with the full export process: packaging, customs declaration, and ocean freight. We can provide FOB, CIF, and other trade terms.
Q10: What is your packaging method? Is it suitable for long-distance ocean shipping?
> Export-standard packaging:
> – Large items / complete machines**: Rust prevention + waterproof film + fumigated solid wood pallet
> – Precision components: Wooden case with shock-absorbing filling
> – Random accessories: Categorized packing with detailed packing list
> All wooden packaging meets IPPC fumigation standards for direct customs clearance.
Q11: What is your minimum order quantity?
> We do not have a strict minimum order quantity. Single-unit orders are welcome. Bulk orders can enjoy more favorable pricing.
INSTALLATION & AFTER-SALES
Q12: Do you provide installation guidance? Do engineers need to come to site?
> We offer two service options:
> 1. Remote guidance: Detailed installation drawings and operation manuals, video guidance for installation (free of charge)
> 2. On-site service: Dispatch engineers to site for installation and commissioning (travel costs are additional)
> Most customers choose remote guidance. Our equipment is designed as a modular structure for easy installation.
Q13: What is the warranty period? What are the wearing parts?
> Standard warranty period is 12 months (from the date of arrival at port).
> Wearing parts list:
> – Chain / screw flights: Approximately 1–3 years, depending on material abrasiveness
> – Liners: Approximately 2–4 years
> – Bearings: Approximately 2–3 years
> We recommend ordering a wearing-parts spare kit together with your first order.
Q14: How do you solve problems during operation?
> We provide 7×24 technical support:>
> – Response within 24 hours for technical issues
> – Remote video troubleshooting guidance
> – Engineer on-site service when necessary
> – Common spare parts in stock for fast delivery
QUOTATION & COOPERATION
**Q15: How can I get a quote? How long does it take?
> Quotation process:
> 1. You provide material parameters, capacity, installation conditions, and other requirements
> 2. Our engineers evaluate and select the appropriate model
> 3. Formal quotation and technical proposal provided within 7 working days
> You can contact us via email, or the online inquiry form.
Q16: What are your payment terms?
> Standard payment terms:
> – 30% advance payment: After contract signing, to start production
> – 70% balance: Before shipment, or against copy of Bill of Lading
For long-term cooperative customers, more flexible payment terms can be negotiated.
Follow these 3 steps to find your ideal conveyor solution
Step 1: Identify Your Material Type
Different materials require different conveyor designs. Tell us what you are conveying:
| Material Category | Examples | Recommended Conveyor Type |
| Powder / Fine Granules | Fly ash, cement powder, lime powder | Screw Conveyor |
| Small Granules / Pellets | Biomass pellets, plastic granules, grain | Screw Conveyor / Belt Conveyor |
| Fragments / Chips | Wood chips, bark, agricultural residues | Chain Scraper Conveyor |
| Bulky / Abrasive | Bottom ash, slag, MSW, clinker | Chain En-Masse Conveyor |
| Vertical Lift | Any bulk material needs vertical transport | Bucket Elevator |
Step 2: Define Your Working Conditions
Please prepare the following parameters before contacting us:
| Parameter | Why It Matters | Example |
| Capacity (t/h) | Determines conveyor size and power | 10 t/h, 50 t/h, 100 t/h |
| Conveying Distance (m) | Determines machine length | 15m horizontal, 30m incline |
| Incline Angle (°) | Affects capacity and design | 0° horizontal, 30° incline |
| Material Temperature (°C) | Determines material grade | Ambient, 150°C, 300°C |
| Moisture Content (%) | Affects discharge design | Dry, damp, wet (needs dewatering) |
| Abrasiveness | Determines liner thickness | Low, medium, high |
| Application Industry | Determines certification needs | Power plant, cement, mining, recycling |
Step 3: Choose Configuration Options
Based on your answers above, our engineers will recommend:
Material grade — carbon steel / wear-resistant steel / stainless steel
Sealing type — open trough / fully enclosed / gas-tight
Drive system — motor power, gearbox brand, speed range
Auxiliary options — explosion-proof motor, cooling jacket, cleaning device, level sensors
Not Sure Where to Start?
Send us your basic requirements, and our engineers will design a customized solution for you — completely free.
Email: bootec@bootecgroup.com Response time: Within 24 hours
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