Equipment Introduction
The bucket elevator is a core piece of vertical, enclosed, continuous bulk material conveying equipment. It relies on circulating buckets within the casing to vertically transfer materials from a low to a high position. It is widely used in complete production lines for organic fertilizer and compound fertilizer, and is also applied in the grain, chemical, mining, and building materials industries.
- Core Advantages
1) Minimal Footprint: Pure vertical conveying, occupying only a small amount of ground space, suitable for compact factory layouts;
2) Fully Enclosed and Dustproof: The entire machine is sealed with steel plates, preventing dust leakage and meeting the environmental protection requirements of fertilizer plants;
3) Low Energy Consumption and Stable Conveying: Low vertical lifting resistance, with power consumption per unit material far lower than belt-driven inclined conveyors;
4) Full Range of Models: Available in three types: TD belt type, TH chain type, and NE plate chain heavy-duty type, suitable for dry powder, wet granules, and high-temperature lumpy materials;
5) Adjustable Height: Standard lifting height 4–40m, with support for customized height increases, compatible with silos, dryers, wrapping machines, packaging machines, and other equipment;
6) Low Breakage Design: Shallow/deep hoppers are available, gently scooping and unloading, with a fertilizer granule breakage rate of <1%.
- Applicable Scenarios
| Applicable Materials | Max Material Temperature |
|---|---|
| Dry non‑corrosive powder, granular organic fertilizer, grain, feed | Normal belt ≤60℃, Heat‑resistant belt ≤200℃ |
| Medium‑abrasion compound fertilizer, fermented hot wet manure, small‑lump raw materials | ≤250℃ |
| High‑capacity, high‑density, high‑abrasion ore, heavy‑duty compound fertilizer | ≤250℃, for heavy‑load long‑distance transportation |
Equipment Structure Composition
The entire machine is divided into five major systems: the machine head, intermediate cylinder, machine base, traction hopper assembly, and drive tensioning system. The structure is standardized and components are interchangeable:
- Machine Head Assembly (Upper): Includes drive motor, reducer, head wheel (drive roller/sprocket), discharge port, and maintenance platform with guardrail; the power system drives the traction components in a cyclical motion, and the arc-shaped section of the machine head completes material unloading.
- Intermediate Enclosed Cylinder: Segmented flange-connected steel plate shell, housing the traction components and hopper running channels, with observation and maintenance doors on the side; fully enclosed to prevent dust leakage and material spillage.
- Machine Base Assembly (Bottom): Includes feed inlet, tail wheel (tensioning roller/sprocket), screw manual tensioning mechanism, and cleaning and maintenance port; the tensioning device adjusts the belt/chain tension to prevent slippage and deviation; the bottom allows for cleaning of clumped residual material.
- Traction and Hopper Assembly (Core Conveying Unit)
- Traction Components: Three types: belt, ring chain, and plate chain;
- Hoppers: Shallow hopper (for moist, sticky materials), deep hopper (for dry, free-flowing particles), stamped from wear-resistant steel plate, bolted to the traction components;
- Supporting Auxiliary Components: Anti-deviation limit switch, backstop (to prevent material backflow during shutdown), material level monitoring switch, sealing dustproof pad, shock-absorbing base, lubricating nozzle.
Raw Materials for the Equipment
Bucket elevators are suitable for conveying various forms of bulk materials, but must meet the following basic conditions:
- Form: Powdered, granular, and small lump materials are best suited, such as fertilizer granules, organic fertilizer powder, coal, sand, cement, crushed ore, and grain.
- Bulk Density: Generally suitable for materials with a loose density ρ < 1.5 t/m³.
- Temperature: TD belt type typically requires a material temperature ≤ 60°C (rubber belts have limited temperature resistance); TH ring chain type can reach 250°C; NE plate chain type can adapt to high-temperature materials up to 400°C.
- Unsuitable Materials: Wet sludge, highly viscous materials, materials prone to severe agglomeration, and oversized, sharp, and highly abrasive rocks (which must be crushed first).
Working Principle of the Equipment
The working principle of a bucket elevator mainly consists of four continuous stages: loading, lifting, unloading, and empty bucket return.
- Loading (Feeding): Material enters from the feed inlet at the bottom of the equipment and is loaded into the buckets using either a scooping or inflow method. Scooping is suitable for powdery or granular materials, where the buckets directly scoop up material as they pass through the bottom storage area; inflow is suitable for lumpy or abrasive materials, where the material flows directly into the buckets.
- Lifting: The buckets, filled with material, are driven by a traction component (belt or chain) to move upwards at a constant speed along the ascending channel within the enclosed casing. The entire process is continuous.
- Unloading After the hopper is lifted to the top and passes the head wheel, it is thrown into the discharge port in one of three ways, depending on the material characteristics and equipment type:
1) Centrifugal unloading: Utilizing centrifugal force to throw the material out; suitable for dry, free-flowing powdery or granular materials.
2) Gravity unloading: The material slides down under its own weight; suitable for lumpy, abrasive, or moist materials.
3) Mixed unloading: A combination of both.
- Empty Hopper Return After unloading, the empty hopper continues to be carried by the traction component around the top and returns to the bottom along the descending channel (unloaded branch), re-entering the loading area. This cycle repeats continuously, achieving continuous vertical conveying.
The entire process is completed within a sealed casing, effectively preventing dust leakage.
Applications of the equipment
Bucket elevators are used in almost all industrial sectors that require the vertical transport of bulk materials:
| Industry | Typical Application Scenarios |
|---|---|
| Fertilizer Industry | Vertical lifting and inter‑process transfer of organic fertilizer, compound fertilizer, NPK granular and powder raw materials |
| Cement & Building Materials | Lifting raw meal, clinker, cement, limestone and gypsum into silos |
| Grain Processing | Vertical conveying for grain, seeds and feed in drying, storage and packaging lines |
| Chemical Industry | Lifting and batching of urea, ammonium phosphate, potash fertilizer and chemical powder |
| Mining & Metallurgy | Vertical transportation of coal, ore, mineral powder and coke |
| Port & Wharf | Ship loading, unloading and warehouse stacking for bulk materials |
Equipment demand groups
Bucket elevators are intended for all industrial users who need vertical bulk material transportation, mainly including:
- Fertilizer production enterprises: organic fertilizer factory, compound fertilizer factory, BB fertilizer factory, high-tower fertilizer factory, used for vertical transportation of raw materials and finished products.
- Grain and feed processing enterprises: upgrading and warehousing of grain drying lines and feed processing lines.
- Cement and building materials companies: efficient warehousing of raw materials, clinker, and finished cement products.
- Chemical and mining enterprises: vertical transportation of granular and powdery chemical raw materials and ores.
- Port and logistics warehousing: loading, unloading and silo stacking of bulk materials.
Standard operating procedures and full lifecycle maintenance methods
| Module Category | Operation Stage | Key Operation & Maintenance Points |
|---|---|---|
| Operation Specification | Pre‑start Preparation | Check fastening bolts and housing sealing; confirm bearing housing and reducer oil level; inspect tensioning device; clean residual materials inside housing; clear feeding port and remove bulk lumps and metal debris from materials. |
| Operation Specification | Start‑up Operation | Start with no‑load, verify motor rotation direction; feed materials evenly after no‑fault running; adjust running speed according to throughput; forbid loaded start‑up. |
| Operation Specification | In‑operation Monitoring | Monitor motor running status and abnormal noise; check buckets for jamming or deviation; observe discharging condition and material returning; detect bearing temperature. |
| Operation Specification | Shutdown Operation | Stop feeding first; turn off main motor after all internal materials are conveyed out; clean residual materials inside housing periodically. |
| Maintenance | Lubrication Maintenance | Fill gear oil for reducer for first time, replace oil every 4 months; fill or replace grease for bearing housing every 3 months; inspect head and tail wheel bearings regularly; apply lubricant for chain transmission parts periodically. |
| Maintenance | Periodic Inspection | Calibrate bucket belt / chain tension; check buckets for wear, deformation and falling‑off; inspect wear of head and tail wheels; check aging and cracks of traction components(belt / chain); fasten all connecting bolts. |
| Safety Regulation | Safety Regulation | Special personnel for equipment management and maintenance; no internal maintenance during running; forbid start‑up without qualified earthing protection. |
Application Technology of Bucket Elevators in Fertilizer Production Lines
Complete Fertilizer Production Line Process Link (Multiple Bucket Elevators Included)
Raw Material Bin → TD/TH Bucket Elevator → Crusher → Batching and Mixing Machine → Bucket Elevator → Granulator → Dryer → Cooler → Bucket Elevator → Coating Machine → Screening Machine → Finished Product Bin → Automatic Packaging Machine
Sectional Logic
- Raw Material Section: Straw and manure piled on the ground are vertically lifted to the feed inlet of the crusher and mixer, saving manual handling.
- Granulation and Drying Section: Wet granules are lifted into the drum dryer, and after drying, the high-temperature granules are lifted and transferred for cooling.
- Finished Product Refining Section: After cooling, the fertilizer is vertically fed into the coating machine and screening equipment. The screened fine powder is returned to the mixer for secondary granulation via a small elevator.
- Storage and Packaging Section: Finished granules are lifted to a high-level bin and flow into the automatic packaging machine by gravity.
Common Faults, Causes, and Standardized Solutions
| Fault Phenomenon | Root Causes | Professional Solutions |
|---|---|---|
| Belt / chain slipping, overload shutdown | Insufficient tension; over‑feeding; reduced friction of head wheel lining; housing material blockage | 1. Adjust tension screw to increase tension force; 2. Reduce feeding speed; 3. Replace head wheel rubber lining; 4. Stop machine and clear blocked bulk materials |
| Trailing component deviation, housing scraping | Misaligned head‑tail wheels; excessive housing verticality error; skewed belt joint; loose unilateral buckets | 1. Adjust screw rods to align head‑tail wheels horizontally; 2. Calibrate unit verticality (deviation ≤2mm per meter); 3. Re‑bond belt joint; 4. Tighten loose bucket bolts |
| Excessive material returning at head section, capacity drop | Over‑filled buckets; improper discharge baffle position; leakage caused by worn & deformed buckets; mismatched lifting speed | 1. Reduce feeding volume; 2. Lower head discharge baffle; 3. Repair or replace damaged buckets; 4. Adjust motor speed to match materials |
| Abnormal internal noise, bucket hitting housing | Over‑loose traction parts; foreign objects jammed inside housing; loose & falling buckets; worn chain links | 1. Increase tension force; 2. Stop machine and clear foreign matters; 3. Tighten bucket bolts; 4. Replace worn chain / belt |
| Bearing temperature＞60℃, abnormal noise | Insufficient lubrication; bearing wear, dust ingress; shaft misalignment | Stop machine and inject grease; replace bearing for severe wear; clean bearing housing dust cover |
| Chain fracture, belt tearing | Long‑term overload, deviation scraping, impact from bulk hard materials, aging | Replace traction components; realize even feeding; install pre‑screening for impurity removal; replace aged belt periodically |
Summary of Equipment’s Comprehensive Technical Features:
- High Space Utilization: Pure vertical conveying, requiring only 1-3 square meters of factory space, suitable for small and medium-sized fertilizer workshops;
- Environmentally Friendly and Enclosed: Fully enclosed steel plate shell, preventing dust leakage and meeting environmental protection standards for organic fertilizer plants;
- Wide Material Compatibility: Belt, chain, and plate chain structures cover dry, wet, powdery, and granular fertilizers;
- Low Maintenance Costs: Standardized wear parts, clear lubrication and maintenance cycles, and simple parts replacement;
- Continuous Automation: Can be integrated into an entire production line for unattended continuous conveying, with variable frequency speed control to adjust capacity;
- Good Particle Protection: Shallow hopper, low-speed gravity unloading, low fertilizer breakage rate, ensuring the appearance of the finished product.
